U.S. patent application number 11/304662 was filed with the patent office on 2006-05-04 for catheter system for vascular re-entry from a sub-intimal space.
Invention is credited to Benjamin J. Clark, Jeffrey L. Emery, Michael D. Keleher, David J. Kupiecki, Allen W. Madsen, C. Danielle Pinson, Sergio Salinas, Matthew R. Selmon, Brent D. Seybold, Kurt D. Sparks.
Application Number | 20060094930 11/304662 |
Document ID | / |
Family ID | 27581190 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060094930 |
Kind Code |
A1 |
Sparks; Kurt D. ; et
al. |
May 4, 2006 |
Catheter system for vascular re-entry from a sub-intimal space
Abstract
A catheter system and corresponding methods are provided for
accessing a blood vessel true lumen from a sub-intimal plane of the
vessel. The catheter system includes visualization elements for
determining the orientation of the true lumen with respect to the
sub-intimal plane at an identified entry site from a position in
the sub-intimal plane. The entry site is distal to a chronic total
occlusion (CTO). The catheter system also includes a system for
physically securing tissue of the sub-intimal plane at the entry
site to the catheter system. The attaching system reduces or
eliminates catheter float within the sub-intimal space. The
catheter system further includes re-entry devices to establish and
maintain a path from the sub-intimal plane back into the vessel
true lumen.
Inventors: |
Sparks; Kurt D.; (Palo Alto,
CA) ; Emery; Jeffrey L.; (San Mateo, CA) ;
Seybold; Brent D.; (Santa Clara, CA) ; Kupiecki;
David J.; (San Francisco, CA) ; Pinson; C.
Danielle; (Mountain View, CA) ; Madsen; Allen W.;
(San Jose, CA) ; Keleher; Michael D.; (Fremont,
CA) ; Salinas; Sergio; (Redwood City, CA) ;
Clark; Benjamin J.; (Redwood City, CA) ; Selmon;
Matthew R.; (Atherton, CA) |
Correspondence
Address: |
COURTNEY STANIFORD & GREGORY LLP
P.O. BOX 9686
SAN JOSE
CA
95157
US
|
Family ID: |
27581190 |
Appl. No.: |
11/304662 |
Filed: |
December 13, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10010410 |
Dec 5, 2001 |
7004173 |
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11304662 |
Dec 13, 2005 |
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60251756 |
Dec 5, 2000 |
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60255729 |
Dec 14, 2000 |
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60263350 |
Jan 22, 2001 |
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60263397 |
Jan 22, 2001 |
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60263579 |
Jan 22, 2001 |
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60263580 |
Jan 22, 2001 |
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60263589 |
Jan 22, 2001 |
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60268263 |
Feb 12, 2001 |
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60301537 |
Jun 27, 2001 |
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60329936 |
Oct 17, 2001 |
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Current U.S.
Class: |
600/104 |
Current CPC
Class: |
A61B 90/37 20160201;
A61B 2017/22094 20130101; A61B 17/320783 20130101; A61B 2017/22077
20130101; A61B 2017/00252 20130101; A61B 17/3207 20130101; A61B
2090/3782 20160201; A61B 2090/378 20160201; A61B 2017/22095
20130101 |
Class at
Publication: |
600/104 |
International
Class: |
A61B 1/00 20060101
A61B001/00 |
Claims
1. A method for accessing a true lumen of a blood vessel from a
sub-intimal plane of the vessel, comprising: identifying a site to
enter the true lumen from a position in the sub-intimal plane
distal to a chronic total occlusion (CTO); determining an
orientation of the true lumen with respect to the sub-intimal plane
at the selected site; physically securing tissue of the sub-intimal
plane at the selected site; and establishing a path from the
sub-intimal plane into the vessel true lumen.
2. A method for crossing a chronic total occlusion (CTO) in
vasculature, comprising: forming a track from a true lumen into a
sub-intimal space of a blood vessel, wherein the track extends from
a position proximal to the CTO in the true lumen to a position
distal to the CTO in the sub-intimal space; determining an
orientation of the true lumen with respect to the sub-intimal plane
at an identified re-entry site from a position in the sub-intimal
plane, wherein the re-entry site is distal to the CTO; physically
securing tissue of the sub-intimal plane at the selected site; and
selectively forming a path from the sub-intimal plane back into the
true lumen.
3. A catheter system for accessing a true lumen of a blood vessel
from a sub-intimal plane of the vessel, comprising: at least one
visualization element for determining an orientation of the true
lumen with respect to the sub-intimal plane at an identified entry
site from a position in the sub-intimal plane distal to a chronic
total occlusion (CTO); at least one system for physically securing
tissue of the sub-intimal plane at the entry site to the catheter
system; and at least one re-entry device for establishing and
maintaining a path from the sub-intimal plane into the vessel true
lumen.
4. A catheter system for crossing chronic total occlusions (CTOs)
in vasculature, comprising: means for forming a track from a true
lumen into a sub-intimal space of a blood vessel, wherein the track
extends from a position proximal to the CTO in the true lumen to a
position distal to the CTO in the sub-intimal space; means for
determining an orientation of the true lumen with respect to the
sub-intimal plane at an identified re-entry site, wherein the
re-entry site is distal to the CTO; means for physically securing
tissue of the sub-intimal plane at the selected site; and means for
selectively forming a path from the sub-intimal plane back into the
true lumen.
Description
[0001] This application relates to and claims the benefit of the
following U.S. Patent Application Nos. 60/251,756 filed Dec. 05,
2000; 60/255,729 filed Dec. 14, 2000; 60/263,350, 60/263,397,
60/263,579, 60/263,580, and 60/263,589, all filed Jan. 22, 2001;
60/268,263 filed Feb. 12, 2001; 60/301,537 filed Jun. 27, 2001; and
60/329,936 filed Oct. 17, 2001; all of which are incorporated
herein by reference in their entirety.
TECHNICAL FIELD
[0002] The disclosed embodiments relate to catheter systems for
crossing vascular occlusions.
BACKGROUND
[0003] An interventional guide wire or other interventional device
is often used in medical procedures that attempt to establish a
pathway through a heavily stenosed or chronically occluded vessel.
A chronically occluded vessel is referred to as containing a
chronic total occlusion (CTO). During these procedures, the guide
wire or device can only be of clinical benefit to establish vessel
patency if it is advanced distally into the vessel true lumen.
[0004] At times during the.process of advancing the guide wire or
device through the stenosed vessel or CTO, and beyond the control
of the operator, the guide wire or device may inadvertently enter
into the wall of the vessel itself, i.e. the sub-intimal plane or
space, or dissection plane. Once in this sub-intimal plane, it
becomes difficult to navigate the guide wire or device through the
sub-intimal tissue to re-gain access into the vessel true lumen at
points distal to the occlusion. The layer of tissue that separates
the vessel true lumen from the sub-intimal plane is typically in
the range from 100 to 500 micrometers for vessels in the diameter
range from 2 mm to 4 mm, and from 100 to 3000 microns, in the
largest vessels of the body. The composition of the tissue may be
such that no guide wire or interventional device currently on the
market can re-access the true lumen.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1 is a catheter system of an embodiment including a
rotational cutting element for re-entry and an imaging element for
visualization.
[0006] FIG. 2 is a catheter system including a forward cutting
element for re-entry, under an alternative embodiment, and an
imaging element for visualization.
[0007] FIG. 3 is a catheter system including a reverse cutting
element for re-entry, under yet another alternative embodiment, and
an imaging element for visualization.
[0008] FIG. 4 is a catheter system including a lumen for receiving
at least one of an optical fiber system, a radio frequency (RF)
system, and a specialized guide wire, as another embodiment for
re-entry, and an imaging element for visualization.
[0009] FIG. 5 is a catheter system embodiment including radio
frequency (RF) electrodes or contacts for re-entry and an imaging
element for visualization.
[0010] FIG. 6 is a catheter system embodiment including radio
frequency (RF) electrodes or contacts of an alternative
configuration for re-entry and an imaging element for
visualization.
[0011] FIG. 7A is a catheter system embodiment including separate
radio frequency (RF) electrode ports and vacuum/guide wire ports,
along with an imaging element for visualization.
[0012] FIG. 7B is a catheter system embodiment including a lumen
that accepts a fiber optic system or a guide wire, separate vacuum
ports, and an imaging element for visualization.
[0013] FIG. 8 is a catheter system of an embodiment including
tissue-holding skewers, a re-entry element or pierce tool, and an
imaging element for visualization.
[0014] FIG. 9A is a catheter system including a nosecone with an
internal ramp to guide an internal cannula element or laser for
re-entry, under an embodiment.
[0015] FIG. 9B is a catheter system in an initial position prior to
cannula deployment, under the embodiment of FIG. 9A.
[0016] FIG. 9C is a catheter system with a cannula deployed and a
re-entry element advanced across sub-intimal tissue, under the
embodiment of FIG. 9A.
[0017] FIG. 9D is a catheter system with a cannula advanced into a
vessel true lumen, under the embodiment of FIG. 9A.
[0018] FIG. 9E is a catheter system following retraction of a
re-entry element with the cannula maintained in the vessel true
lumen, under the embodiment of FIG. 9A.
[0019] FIG. 9F is a catheter system with a guide wire advanced into
a vessel true lumen, under the embodiment of FIG. 9A.
[0020] FIG. 10A is a catheter system including a nosecone with an
internal ramp to guide a specialized guide wire for re-entry, under
an alternative embodiment of FIGS. 9A and 9B.
[0021] FIG. 10B is a catheter system including a nosecone, under
the embodiment of FIG. 10A, showing a specialized guide wire
deploying from the internal ramp.
[0022] FIG. 10C is a catheter system including a nosecone, under
the embodiment of FIG. 10A, showing a distal taper of the
specialized guide wire deploying from the internal ramp.
[0023] FIG. 10D is a catheter system including a nosecone, under
the embodiment of FIG. 10A, showing the distal taper of the
specialized guide wire repositioning from the internal ramp through
the nosecone slot.
[0024] FIG. 10E is a catheter system including a nosecone, under
the embodiment of FIG. 10A, showing catheter removal from a
treatment site following deployment of the specialized guide wire
using the nosecone.
[0025] FIG. 11 is a catheter system including a nosecone with an
internal ramp, under an embodiment, for use with a typical guide
wire.
[0026] FIG. 12A is a catheter system including a nosecone with an
internal ramp and an internal slidably disposed tube in a retracted
position, under an embodiment, for use with a typical guide wire,
specialized guide wires, RF systems, and optical fiber systems.
[0027] FIG. 12B is a catheter system including the nosecone with
the internal ramp and internal slidably disposed tube, under the
embodiment of FIG. 12A, where the internal slidably disposed tube
is in an extended position.
[0028] FIG. 13 is a catheter system including a curved distal
catheter tip, under an embodiment, for guiding typical guide wires,
specialized guide wires, optical fiber systems, and RF systems.
[0029] FIG. 14A is a catheter system of an embodiment including a
nosecone with an internal slidably disposed push ramp for guiding
typical guide wires, specialized guide wires, optical fiber
systems, and RF systems.
[0030] FIG. 14B is a catheter system under the embodiment of FIG.
14A showing the internal slidably disposed push ramp in a retracted
position.
[0031] FIG. 15 is a catheter system including a dual lumen shaft
that transitions distally to a single lumen shaft, under an
embodiment.
[0032] FIG. 16 is a specialized guide wire including a distal end
that is machined to provide cutting flutes, under an
embodiment.
[0033] FIG. 17A is an optical fiber system of an embodiment,
capable of deployment in a catheter system, for delivering laser
energy to a distal termination.
[0034] FIG. 17B is an optical fiber system including a lumen, under
an alternative embodiment of FIG. 17A.
[0035] FIG. 18 is a slidably disposed element that translates
within a catheter lumen and includes one or more electrodes capable
of transmitting radio frequency energy, under an embodiment.
[0036] FIG. 19 is a rotational Intra-Vascular Ultrasound (IVUS)
element including an integral distal tip for re-entry, under an
embodiment.
[0037] FIG. 20 is a flow diagram for vascular re-entry from a
sub-intimal space.
[0038] FIG. 21 is a flow diagram for identifying and determining
orientation of a vessel true lumen using IVUS, under an
embodiment.
[0039] FIG. 22 is a flow diagram for identifying and determining
orientation of a vessel true lumen using OCT, under an
embodiment.
[0040] FIG. 23 is a flow diagram for identifying and determining
orientation of a vessel true lumen using optical fiber
visualization systems, under an embodiment.
[0041] FIG. 24 is a flow diagram for identifying and determining
orientation of a vessel true lumen using Doppler ultrasound
systems, under an embodiment.
[0042] FIG. 25 is a flow diagram for identifying and determining
orientation of a vessel true lumen using fluoroscopic marking
systems, under an embodiment.
[0043] FIG. 26 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site by evacuating fluid of the sub-intimal
plane, under an embodiment.
[0044] FIG. 27 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site using vacuum, under an embodiment.
[0045] FIG. 28 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site using mechanical devices, under an
embodiment.
[0046] FIG. 29 is a flow diagram for cutting through sub-intimal
tissue into a true lumen, under an embodiment.
[0047] FIG. 30 is a flow diagram for piercing a pathway through
sub-intimal tissue into a true lumen, under an embodiment.
[0048] FIG. 31 is a flow diagram for establishing a pathway through
sub-intimal tissue into a true lumen, under an alternative
embodiment.
[0049] FIG. 32 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under an embodiment.
[0050] FIG. 33 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a first alternative embodiment.
[0051] FIG. 34 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a second alternative embodiment.
[0052] FIG. 35 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a third alternative embodiment.
[0053] FIG. 36 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a fourth alternative embodiment.
[0054] FIG. 37 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a fifth alternative embodiment.
[0055] FIG. 38 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a sixth alternative embodiment.
[0056] FIG. 39 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a seventh alternative embodiment.
[0057] FIG. 40 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under an eighth alternative embodiment.
[0058] FIG. 41 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a ninth alternative embodiment.
[0059] FIG. 42 is a flow diagram for establishing a path into a
vessel true lumen using radio frequency (RF) energy, under an
embodiment.
[0060] FIG. 43 is a flow diagram for establishing a path into a
vessel true lumen using RF energy, under a first alternative
embodiment.
[0061] FIG. 44 is a flow diagram for establishing a path into a
vessel true lumen using RF energy, under a second alternative
embodiment.
[0062] FIG. 45 is a flow diagram for establishing a path into a
vessel true lumen using RF energy, under a third alternative
embodiment.
[0063] FIG. 46 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under an embodiment.
[0064] FIG. 47 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under a first alternative
embodiment.
[0065] FIG. 48 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under a second alternative
embodiment.
[0066] FIG. 49 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under a third alternative
embodiment.
[0067] FIGS. 50A and 50B are a flow diagram for establishing a path
into a vessel true lumen using laser energy, under a fourth
alternative embodiment.
[0068] FIGS. 51A and 51B are a flow diagram for establishing a path
into a vessel true lumen using laser energy, under a fifth
alternative embodiment.
[0069] FIG. 52 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under a sixth alternative
embodiment.
[0070] In the drawings, the same reference numbers identify
identical or substantially similar elements or acts. To easily
identify the discussion of any particular element or act, the most
significant digit or digits in a reference number refer to the
Figure number in which that element is first introduced (e.g.,
element 902 is first introduced and discussed with respect to FIG.
9).
[0071] Figure numbers followed by the letters "A," "B," "C," etc.
indicate either (1) that two or more Figures together form a
complete Figure (e.g., FIGS. 50A and 50B together form a single,
complete FIG. 50), but are split between two or more Figures
because of paper size restrictions, amount of viewable area within
a computer screen window, etc., or (2) that two or more Figures
represent alternative embodiments or methods under aspects of the
invention.
[0072] Unless described otherwise below, the construction and
operation of the various blocks and components shown in the figures
are of conventional design. As a result, such blocks need not be
described in further detail herein, because they will be understood
by those skilled in the relevant art. Such further detail is
omitted for brevity and so as not to obscure the detailed
description of the invention. Any modifications necessary to the
blocks or components in the figures can be readily made by one
skilled in the relevant art based on the detailed description
provided herein.
[0073] The headings provided herein are for convenience only and do
not necessarily affect the scope or meaning of the claimed
invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0074] A catheter-based system, or catheter system, is described
for the purpose of gaining access to the true lumen of a blood
vessel (coronary or peripheral artery or vein) from a space within
the vessel wall itself, referred to herein as a sub-intimal plane,
or dissection plane. Throughout this document, the various catheter
embodiments are referred to as the re-entry catheter or catheter
system.
[0075] The following description provides specific details for a
thorough understanding of, and enabling description for,
embodiments of the invention. However, one skilled in the art will
understand that the invention may be practiced without these
details. In other instances, well-known structures and functions
have not been shown or described in detail to avoid unnecessarily
obscuring the description of the embodiments of the invention.
[0076] Unless described otherwise herein, the embodiments described
herein are well known or described in detail in the above-noted and
cross-referenced provisional patent applications. Indeed, much
of.the detailed description provided herein is explicitly disclosed
in the provisional patent applications; most or all of the
additional material of aspects of the invention will be recognized
by those skilled in the relevant art as being inherent in the
detailed description provided in such provisional patent
applications, or well known to those skilled in the relevant art.
Those skilled in the relevant art can implement aspects of the
invention based on the detailed description provided in the
provisional patent applications.
[0077] FIGS. 1 through 19 show numerous different embodiments of
catheter systems or platforms and associated components. For each
system, the different methods and steps described may be combined
to construct unique embodiments. Note that the various combinations
of methods and steps yield additional embodiments of the catheter
system. It is understood by those skilled in the art that these
additional combinations/embodiments are intuitive in view of the
platforms presented herein. A description of the numerous
embodiments now follows.
[0078] FIG. 1 is a catheter system 100 of an embodiment including a
rotational cutting element 102 for re-entry and an imaging element
104 for visualization. In addition to the rotational or crown
cutting element 102 and the imaging element 104, the catheter
system 100 includes an outer shaft 106 that houses at least one
vacuum lumen 108 or port. The outer shaft 106 couples to a nosecone
110 that includes a guide wire lumen 112. A typical outside
diameter of the outer shaft/nosecone is approximately 0.060 inches,
while that of the cutting element is approximately 0.045 inches and
that of the imaging element is approximately 0.030 inches, but the
embodiment is not so limited.
[0079] FIG. 2 is a catheter system 200 including a forward cutting
element 202 for re-entry, under an alternative embodiment, and an
imaging element 204 for visualization. In addition to the forward
or beveled needle cutting element 202 and the imaging element 204,
the catheter system 200 includes an outer shaft 206 that houses at
least one vacuum lumen 208 or port. The outer shaft 206 couples to
a nosecone 210 that includes a guide wire lumen 212.
[0080] FIG. 3 is a catheter system 300 including a reverse cutting
element 302 for re-entry, under yet another alternative embodiment,
and an imaging element 304 for visualization. In addition to the
reverse cutting element 302 and the imaging element 304, the
catheter system 300 includes an outer shaft 306 that houses at
least one vacuum lumen 308 or port. The outer shaft 306 couples to
a nosecone 310 that includes a guide wire exit lumen 312.
[0081] FIG. 4 is a catheter system 400 including at least one lumen
402 for receiving re-entry working elements 414 including optical
fiber systems, rotational Intra-Vascular Ultrasound (IVUS) systems
including those having a specialized distal tip, radio frequency
(RF) systems, and specialized guide wires. The catheter system 400
includes a nosecone 410 coupled to a catheter outer body 406. The
catheter outer body 406 includes a marker band for fluoroscopic
visualization 422.
[0082] The nosecone 410 includes the lumen 402 for receiving any of
a variety of working elements 414. The lumen 402 for receiving
working elements terminates with an exit ramp 418 and a lateral
exit port.
[0083] The nosecone 410 also includes a lumen 416 for receiving
working elements including an imaging element 404 and a guide wire
(not shown), for example. A visualization window 424 is included
for use with the imaging element 404. The lumens 402 and 416 may
also serve as vacuum ports or pathways 420, but are not so limited.
The nosecone 410 also includes a guide wire exit lumen 412 in a
distal end.
[0084] FIG. 5 is a catheter system embodiment 500 including radio
frequency (RF) electrodes or contacts 502 for re-entry and an
imaging element 504 for visualization. In addition to the RF
electrodes 502 and the imaging element 504, the catheter system 500
includes an outer shaft 506 that houses at least one vacuum lumen
508 or port. The outer shaft 506 couples to a nosecone 510 that
includes a distal guide wire exit lumen 512.
[0085] FIG. 6 is a catheter system embodiment 600 including radio
frequency (RF) electrodes or contacts 602 of an alternative
configuration. In addition to the opposing RF electrodes 602 the
catheter system 600 includes an imaging element 604 and at least
one vacuum lumen 608 or port. The nosecone 610 includes a distal
guide wire exit lumen 612, but other embodiments may not include
the exit lumen 612.
[0086] FIG. 7A is a catheter system embodiment 700 including a
nosecone 710 having separate ports 702 that accept radio frequency
(RF) electrodes 712 for vessel tissue ablation. Further, the
nosecone 710 includes a vacuum and guide wire port 704, or vacuum
port. The vacuum port 704, besides delivering vacuum to the
nosecone, accepts working elements including, for example, a guide
wire 714. The nosecone also includes an imaging element 706 and a
distal guide wire port 708.
[0087] FIG. 7B is a catheter system embodiment 750 including a
nosecone 760 with a lumen 754 that accepts working elements 764
including guide wires and fiber optic tissue systems, for example
fiber optic tissue ablation systems. Further, the nosecone 760
includes separate vacuum lumens or ports 752 that deliver vacuum to
the nosecone. The nosecone also includes an imaging element 756 and
a distal guide wire port 758.
[0088] FIG. 8 is a catheter system 800 of an embodiment having a
nosecone 810 that accommodates tissue-holding skewers 802, a
re-entry element or pierce tool 804, and an imaging element 806 for
visualization. The lumen 808 carrying the pierce tool 804 can be
used to support introduction of a guide wire (not shown). The
nosecone 810 also includes a guide wire exit lumen 812. The lumens
814 that accept the tissue holding skewers 802 also provide vacuum
to the nosecone 810.
[0089] FIG. 9A is a catheter system including a nosecone 902 with
an internal ramp 904 to guide an internal cannula element and a
re-entry laser system, under an embodiment. The nosecone 902 also
includes a guide wire distal exit port 906, and a cutout 908 to
guide fluoroscopic alignment. A side view 912, top view 914 and
front view 916 of the nosecone 902 are shown.
[0090] FIG. 9B is a catheter system in an initial position prior to
cannula deployment, under the embodiment of FIG. 9A. The catheter
shaft 930 and nosecone 902 is positioned within a sub-intimal plane
940 of the vessel wall 950. The cannula 920 is positioned in the
catheter system at a position proximal to the exit ramp 904. The
re-entry element 924 is advanced into the cannula 920. A variety of
re-entry elements or devices 924 are deployable through the cannula
920, including typical guide wires, specialized guide wires (see
FIG. 16 and the associated description herein), fiber optic systems
(see FIGS. 17A and 17B and the associated description herein), RF
electrode systems (see FIG. 18 and the associated description
herein), and Intra-Vascular Ultrasound Systems (IVUS) (see FIG. 19
and the associated description herein). When the IVUS system is
used for visualization, its visualization position 926 is shown.
The catheter system of an embodiment also includes vacuum ports
922.
[0091] FIG. 9C is a catheter system with the slidably disposed
cannula 920 deployed from the nosecone 902 via the exit ramp 904.
The re-entry element 924 advances across sub-intimal tissue 942,
establishing a path into the vessel true lumen 960. FIG. 9D shows
the cannula 920 advanced into the vessel true lumen 960. FIG. 9E is
the catheter system following retraction of the re-entry element
924 with the cannula 920 maintained in the vessel true lumen 960,
under the embodiment of FIG. 9A. FIG. 9F shows a guide wire 928
advanced into the vessel true lumen 960 through the cannula 920,
following retraction of the re-entry element 924.
[0092] FIG. 10A is a catheter system including a nosecone 1002 with
an internal ramp to guide a specialized guide wire for re-entry,
under an alternative embodiment of FIGS. 9A and 9B. The nosecone
1002 of this embodiment has a modified guide wire exit port 1006 to
accommodate the specialized guide wire or a specialized cannula.
FIGS. 10B-10E show deployment of the specialized guide wire.
[0093] FIG. 10B shows the specialized guide wire 1010 in an initial
phase of deployment using the internal ramp 1012. The specialized
guide wire 1010 of an embodiment includes at least one distal taper
section 1014. FIG. 10C shows the specialized guide wire 1010 in a
further state of deployment. FIG. 10D shows that the nosecone slot
1016 allows the specialized guide wire 1010 to translate or
reposition 1020 into the guide wire exit port 1006 as the distal
taper section 1014 of the specialized guide wire 1010 reaches the
top of the exit ramp 1012. FIG. 10E shows that the nosecone 1002
and catheter system are retracted 1030 or removed from a treatment
site following deployment of the specialized guide wire using the
nosecone.
[0094] FIG. 11 is a catheter system 1100 including a nosecone 1102
coupled to a catheter shaft 1104. The nosecone 1102 includes an
internal ramp 1106. A variety of working elements or devices 1108
are deployable using the internal ramp 1106, including typical
guide wires, specialized guide wires (see FIG. 16 and the
associated description herein), fiber optic systems (see FIGS. 17A
and 17B and the associated description herein), RF system
components (see FIG. 18 and the associated description herein), and
IVUS (see FIG. 19). The catheter system 1100 further includes a
vacuum lumen 1110 and at least one region 1112 housing fluoroscopic
visualization elements.
[0095] FIG. 12A is a catheter system 1200 including a nosecone 1202
with an internal ramp 1204 and an internal slidably disposed tube
1206, under an alternative embodiment of FIGS. 9A, 9B, and 10A-10E.
The position of the internal tube 1206 is controllable to aid in
steering a working element 1208 deployed via the catheter system
1200. When the internal tube 1206 is in this retracted position,
the working element 1208 is deployed at a shallower deployment
angle relative to a longitudinal axis of the catheter system 1200.
FIG. 12B shows the catheter system 1200 when the internal tube 1206
is in an extended position. Extension of the internal tube 1206
results in deployment of the working element 1208 at deployment
angles that are progressively more acute. A variety of working
elements or devices 1208 are deployable using the internal ramp
1204, including typical guide wires, specialized guide wires (see
FIG. 16 and the associated description herein), fiber optic systems
(see FIGS. 17A and 17B and the associated description herein), RF
system components (see FIG. 18 and the associated description
herein), and IVUS (see FIG. 19 and the associated description
herein).
[0096] FIG. 13 is a catheter system 1300 including a curved distal
catheter tip 1302, under an embodiment. The curved distal tip 1302
is coupled to a distal coil 1304 that, in one embodiment, is formed
from platinum. The distal coil 1304 may include a visualization
window 1306, but is not so limited. The distal coil 1304 couples to
a braided catheter shaft 1308, but may be used with various types
of catheter shafts known in the art. The catheter system 1300 can
be used for guiding various working elements including typical
guide wires, specialized guide wires, optical fiber systems (see
FIGS. 17A and 17B and the associated description herein), and IVUS
(see FIG. 19 and the associated description herein).
[0097] FIGS. 14A and 14B show a catheter system 1400 including a
catheter shaft 1401 having a nosecone 1402 with an internal
slidably disposed push ramp 1404 coupled to an internal push tube
1406. Extension of the internal push ramp 1404 (FIG. 14A) helps in
directing a working element 1410 to a re-entry site. The nosecone
1402 further includes a nosecone slot 1408 that allows the working
element 1410 to translate or reposition into the guide wire exit
port 1412 as the internal ramp 1404 is retracted (FIG. 14B). A
variety of working elements or devices 1410 are deployable using
the internal push ramp 1404, including typical guide wires,
specialized guide wires (see FIG. 16 and the associated description
herein), fiber optic systems (see FIGS. 17A and 17B and the
associated description herein), RF system components (see FIG. 18
and the associated description herein), and IVUS (see FIG. 19 and
the associated description herein).
[0098] FIG. 15 is a catheter system 1500 including a catheter shaft
having dual lumens 1502 and 1504 in a proximal region, under an
alternative embodiment of FIG. 13. In a distal region, the two
lumens 1502 and 1504 merge to form a single lumen 1506. A variety
of working elements or devices are deployable using this catheter
system 1500, including typical guide wires, specialized guide wires
(see FIG. 16 and the associated description herein), fiber optic
systems (see FIGS. 17A and 17B and the associated description
herein), RF system components (see FIG. 18 and the associated
description herein), and IVUS (see FIG. 19 and the associated
description herein).
[0099] FIG. 16 is a specialized guide wire 1600, under an
embodiment. The guide wire 1600 includes a distal end that is
machined to provide cutting flutes 1602, under an embodiment. In an
alternative embodiment, the distal tip may be processed with a
generally abrasive surface.
[0100] FIG. 17A is an optical fiber system 1700 of an embodiment.
This optical fiber system 1700 can be deployed, using any of the
catheter systems described herein, to deliver laser energy to a
distal termination. The optical fiber system 1700 includes a fiber
optic core 1702 surrounded by an outer sheath 1704. The sheath 1704
can be formed, for example, from polyimide or polyethylene, but is
not so limited. The fiber optic system 1700 terminates at the
distal end in either a normal configuration 1706 or an angled
configuration 1708, relative to the longitudinal axis, but any mode
of termination known in the art may be used. The optical fiber
system 1700 of one embodiment has an outside diameter of
approximately 0.010 to 0.018 inches, but the diameter can vary
depending on the planned application.
[0101] FIG. 17B is an optical fiber system 1750 including a lumen
1752, under an alternative embodiment of FIG. 17A. The lumen 1752
is surrounded by a polymer encasement 1754. The encasement 1754 of
one embodiment is formed, for example, from nylon or polyethylene,
but is not so limited. The encasement 1754 includes individual
optical fibers 1756, where the number of optical fibers 1756 varies
in accordance with planned applications. The individual fibers can
terminate in any mode known in the art. The optical fiber system
1750 of one embodiment has an outside diameter of approximately
0.020 to 0.030 inches, but the diameter can vary with particular
applications.
[0102] FIG. 18 is a radio frequency (RF) element 1800 including one
or more electrodes 1802 capable of transmitting RF energy, under an
embodiment. The RF electrodes 1802 are housed in a polymer
sheathing 1804 that translates within a catheter lumen (not shown).
The polymer sheathing 1804 is formed from polyethylene or nylon,
but other materials may be used. The RF element 1800 can be used
with the catheter system embodiments described herein.
[0103] FIG. 19 is a rotational IVUS element 1900 including an
integral distal tip 1902 for re-entry, under an embodiment. The
distal tip 1902 is coupled to a torqueable drive train 1904. The
element 1900 further includes an imaging element 1906 and an
imaging transducer 1908. The element 1900 is encased in a sleeve
1910 that, in one embodiment, is formed of polyethylene. The
outside diameter of the element is approximately 0.030 inches, but
is not so limited.
[0104] All catheter systems presented herein are delivered to the
vascular site via tracking over a conventional guide wire. In some
instances the guide wire is removed and other catheter elements are
advanced during the course of a procedure involving the catheter
system while, or in other instances, the guide wire remains in the
catheter throughout the procedure.
[0105] FIG. 20 is a flow diagram for vascular re-entry from a
sub-intimal space. In general, the process of re-entry from a
sub-intimal plane into a vessel true lumen of an embodiment is
described herein using three steps, with numerous methods and
embodiments described under each step. Fundamentally, any methods
from any steps can be combined to formulate a valid sequence and
basis for a catheter embodiment to describe the overall procedures.
The three steps include:
[0106] Step 1: Identify and determine the orientation of the vessel
true lumen with respect to the sub-intimal plane. Approaches are
presented under this step including the use of catheter system
on-board guidance, and external guidance. Further, five methods of
visualization are described.
[0107] Step 2: Physically secure the sub-intimal tissue at the
re-entry site, to enable a method of re-entry into the true lumen,
as described in Step 3. Three methods are described herein for
securing the sub-intimal tissue.
[0108] Step 3: Establish a re-entry path from the sub-intimal plane
into the vessel true lumen. Six methods of vessel re-entry are
described below.
The steps are now described in detail, including the associated
methods and embodiments.
[0109] Step 1: Identify and Determine the Orientation of the Vessel
True Lumen With Respect to the Sub-Intimal Plane
[0110] As the catheter is positioned within a sub-intimal plane,
the re-entry mechanism is orientated towards the vessel true lumen.
When the catheter is properly aligned, the re-entry mechnism
directly faces the sub-intimal tissue that separates the dissection
plane from the vessel true lumen.
[0111] Method 1 Under Step 1: Intra-Vascular Ultrasound (IVUS)
(FIGS. 1-15)
[0112] FIG. 21 is a flow diagram for identifying and determining
orientation of a vessel true lumen using IVUS, under an embodiment.
Two IVUS systems are readily available as stand-alone devices that
may serve as an element within the Re-Entry Catheter. One system,
manufactured by Boston Scientific Corporation, utilizes an
ultrasound element, or crystal, which is mounted at the distal end
of a rotational shaft. This shaft is rotated at a specified speed
while the crystal is excited by electrical signals. The crystal
produces acoustic wavefronts, and the reflection of the acoustic
wavefronts by tissue types of varying density are received by the
crystal. Algorithms decipher the reflected acoustic signals, and
the system provides a cross sectional view of the tissue
surrounding the sub-intimal plane. This method easily resolves
surrounding tissue and aids in identifying the vessel true
lumen.
[0113] Another IVUS system, manufactured by Endosonics utilizes an
array of individually mounted crystals or elements in a fixed
circumferential orientation at the distal end of a small catheter
shaft. This system does not rotate. Rather, each crystal is
sequentially excited by an electrical signal and each crystal also
receives the reflected acoustic signal. Algorithms decipher the
reflected signals, and the system constructs a cross sectional
image of the tissue surrounding the crystal network. This method
resolves surrounding tissue and helps identify the vessel true
lumen.
[0114] Typical outer diameter dimensions for IVUS systems are on
the order of approximately 0.030 inches, but are not so
limited.
[0115] Method 2 Under Step 1: Optical Coherence Tomography (OCT)
(FIGS. 1-15)
[0116] FIG. 22 is a flow diagram for identifying and determining
orientation of a vessel true lumen using OCT, under an embodiment.
In general, the OCT system delivers infrared (IR) light into tissue
from the distal end of a rotating optical fiber. Delivery of the
light into the tissue is accomplished by terminating the optical
fiber at an angle to achieve internal reflection of the light at an
approximate right angle to the central axis of the optical fiber.
The fiber also receives reflected light from various tissue types.
While the reflected OCT signals comprise light waves rather than
acoustic waves, the reflected signals are deciphered and a cross
sectional image is produced of the tissue surrounding the distal
tip of the optical fiber, similar to the approach described in
Method 1 under Step 1 above. While this technology has yet to be
released to the market as a tool to be used within the vascular
space, OCT is a proven technology that provides image resolution 5
to 25 times greater than current ultrasound embodiments.
[0117] Further, OCT technology is not able to produce an image
through blood because it uses infrared light. However, the system
of an embodiment evacuates fluids and/or blood from the sub-intimal
plane in an embodiment, as described below. Thus, with the removal
of fluids and/or blood from the sub-intimal plane, the utilization
of infrared light wavelengths allows the OCT technology to create
an image of the surrounding tissue and identify the true lumen.
Further, the wavelength of light may be modified so as to be able
to pass through blood and still produce an image of the surrounding
tissue. Typical outer diameter dimensions for the OCT system are on
the order of approximately 0.015 inches, but are not so
limited.
[0118] Method 3 Under Step 1: Optical Fiber Visualization System
(FIGS. 1-15)
[0119] FIG. 23 is a flow diagram for identifying and determining
orientation of a vessel true lumen using optical fiber
visualization systems, under an embodiment.
[0120] This method uses an optical fiber system for visualization
as in Method 2 under Step 1 above, except that the optical fiber
system does not continuously rotate. A broad-spectrum light is
applied to the proximal end of the optical fiber. The light is
reflected at the distal terminal end of the fiber into surrounding
body tissue by terminating the optical fiber at an approximate
right angle. Specific wavelengths of light are absorbed and/or
transmitted and/or reflected based upon the type of tissue exposed
to the light. The reflected light signals are processed to produce
a spectral graph. This method, therefore, incrementally rotates the
fiber, sending and receiving broadband light signals, until the
specific absorption peaks are received that signal the presence of
the true lumen. Typical outer diameter dimensions of the fiber
optic system may range from 0.010 to 0.020 inches, but are not so
limited.
[0121] This method can be implemented using three techniques that
are now described.
Technique 1 (Method 3 Under Step 1):
[0122] The absorption peak of hemoglobin is sought, which indicates
the presence of a blood pool, i.e. the true lumen. Note that in the
case where re-entry of an artery is desired, the absorption peak
sought is that of oxygenated hemoglobin, which is a double peak
signal having peaks at known wavelengths in the spectrum. Since
large veins also are in close proximity to arteries, it would be
important to distinguish between the single absorption peak of
de-oxygenated hemoglobin, and the desired double peak of oxygenated
hemoglobin. Once the double absorption peaks of de-oxygenated are
identified, the direction of the true lumen is determined.
Technique 2 (Method 3 Under Step 1):
[0123] Local injection into the vessel true lumen with an agent
having a characteristic absorption peak can selectively tag blood
cells only in the vessel true lumen. Various tagging agents
approved by the Food and Drug Administration (FDA) can be used to
tag blood cells. Tagging the blood cells in the vessel true lumen
is accomplished from a distal entry point to the vessel.
[0124] As an example, consider an occlusion in the right coronary
artery of the coronary vasculature. The re-entry catheter described
herein is advanced into the dissection plane. By definition, the
vessel true lumen at this time in the procedure has not been
accessed. However, many times collateral vessels from the left
coronary vasculature will branch to the right coronary artery at
various locations, and often at connection points which are distal
to typical occlusion locations in the right coronary artery. Thus,
by injecting this agent into the left coronary vasculature, some of
the agent will travel through the collateral vessels and feed into
the right coronary artery, distal to the occlusion, i.e. the true
lumen of the vessel the re-entry catheter is attempting to access.
This procedure uses efficient timing of the injection of the agent
and interpretation of the absorption peaks, because the agent will
clear from the distal portion of the right coronary artery
typically within 5-10 seconds. Note that this example is easily
applicable to a blockage in the left arterial system, with
collateral connections from the right coronary artery.
Technique 3 (Method 3 Under Step 1):
[0125] A systemic injection with an agent that tags red blood cells
is used. In this case, the agent tags all viable red blood cells in
the entire vascular system, both arterial and venous. The agent is
chosen to provide an identifiable absorption peak. One advantage of
this method is that a continuous generation of spectral data can be
performed since the agent bond to the blood cells has a long
half-life.
[0126] Method 4 Under Step 1: Doppler Ultrasound (FIGS. 1-8,
15)
[0127] FIG. 24 is a flow diagram for identifying and determining
orientation of a vessel true lumen using Doppler ultrasound
systems, under an embodiment. Doppler ultrasound is also used to
identify blood flow in the vessel true lumen, under an embodiment.
The fundamental basis of this technique is not unlike that used to
generate weather radar maps. The Doppler method emits acoustic
energy from a transducer/receiver mounted in the catheter. The
transducer/receiver subsequently recognizes and measures phase
shifts in these acoustic signals that are reflected off of moving,
formed blood components, e.g. red blood cells and/or white blood
cells in the vessel true lumen, thereby establishing an
orientation. Details of the Doppler method are understood by those
knowledgeable in this art. Typical outer diameter dimensions of the
doppler system are approximately 0.020 inches.
[0128] Note that the visualization hardware referenced in Methods 1
through 4 under Step 1 may be an integral component of the
embodiments of FIGS. 7, 8, and 15, i.e., not removed from the
catheter during the procedure. However, in the embodiments of FIGS.
1 through 6 and 9 through 14 this hardware is used as part of the
catheter system at the beginning of the procedure to determine
orientation of the vessel true lumen, and then removed to allow the
introduction of other elements used to conduct the procedure.
[0129] Method 5 Under Step 1: Fluoroscopic Marking System (FIGS.
1-15)
[0130] FIG. 25 is a flow diagram for identifying and determining
orientation of a vessel true lumen using fluoroscopic marking
systems, under an embodiment. This method describes the use of a
fluoroscopic marking system at the distal end of the catheter to
identify the location of the re-entry mechanism, with respect to
the vessel true lumen. One implementation of this method takes
advantage of the catheter nosecone itself which may be fabricated
from a fluoroscopic material, e.g. stainless steel, platinum, or
gold coated ceramic. For example the side port of the nosecone,
which identifies the re-entry direction of the catheter, should be
readily visible under fluoroscopy. Alternatively, a marking cutout
may be placed within the proximal section of the nosecone, the
design of which would indicate the position of the re-entry
mechanism of the catheter. [0131] Step 2: Physically Secure the
Sub-Intimal Tissue at the Re-Entry Site
[0132] In the formation of a sub-intimal plane, extra-vascular
fluid as well as blood may collect in this space, and the
sub-intimal space may grow in volume. A re-entry catheter advanced
into the sub-initimal space can thus "float" within this space.
This can result in the catheter's inability to establish a
"purchase" on the sub-intimal tissue that separates the catheter
from the vessel true lumen. Thus, it is procedurally important to
evacuate this volume of fluid so as to allow the re-entry portion
of the catheter to be placed in direct, intimate contact with the
sub-intimal tissue. This increases the likelihood of the re-entry
mechanism successfully establishing a re-entry path to the vessel
true lumen.
[0133] Method 1 Under Step 2: Evacuating Fluid of Sub-Intimal Plane
(FIGS. 1-15)
[0134] FIG. 26 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site by evacuating fluid of the sub-intimal
plane, under an embodiment. This method describes the action of
evacuating the volume of fluid that is typically contained within
the sub-intimal plane. The action of evacuating the sub-intimal
plane of all extra-vascular fluid and blood, can subsequently
"lock" the sub-intimal tissue onto the surface of the catheter.
Thus, the sub-intimal tissue that separates the sub-intimal plane
from the true lumen is held in position on the surface of the
re-entry catheter, facilitating a chosen method of creating a
re-entry pathway back to the true lumen.
[0135] More specifically, the embodiments described herein and
shown in the Figures include a distal nosecone having a sideport or
catheter distal termination with ports which may be used to
translate a vacuum to within the sub-intimal space. Note that in
some embodiments the distal guide wire port serves to communicate
vacuum to within the sub-intimal space. Further, additional
evacuation/vacuum ports of various sizes and shapes may be
positioned along the distal portion of the catheter which would
reside in the sub-intimal plane.
[0136] Method 2 Under Step 2: Application of Vacuum (FIGS. 1-3,
5-12, 14)
[0137] FIG. 27 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site using vacuum, under an embodiment. This
method describes the further application of vacuum such that the
sub-intimal tissue that separates the sub-intimal plane from the
vessel true lumen is invaginated within a distal portion of the
catheter. Once this tissue is contained within the interior of the
catheter itself, various methods may be subsequently employed to
establish a physical pathway through it and back to the vessel true
lumen, as detailed below. One advantage of this method is that all
re-entry techniques may be performed within the catheter, reducing
risk to any surrounding vascular tissue and inadvertent perforation
of the vessel wall to the pericardial space.
[0138] Method 3 Under Step 2: Mechanical Means (FIG. 8)
[0139] FIG. 28 is a flow diagram for securing sub-intimal tissue at
a vessel re-entry site using mechanical devices, under an
embodiment. This method describes mechanically securing the
sub-intimal tissue prior to employment of a re-entry mechanism to
gain access into the vessel true lumen, per Step 3 below. Physical
or mechanical securing of the sub-intimal tissue may be
accomplished by a variety of embodiments. Mechanical means
including tweezing or forcep action, pinch rollers, or skewers are
used to grab and secure the sub-intimal tissue. The tweezing- or
forcep-type mechanical system can be used to simply hold the tissue
secure against the nosecone, or grab and pull the sub-intimal
tissue within the nosecone. Skewers may be used to pierce the
sub-intimal tissue and hold it intimately against the catheter, or
grab and pull the sub-intimal tissue within the nosecone. The
skewer tip could remain embedded in the sub-intimal tissue, or
could advance through the tissue such that the skewer tip pierces
in and out of the tissue and the skewer is directed into a
receiving port at the opposite section of the nosecone. In this
last configuration, the tissue is held captive on the skewer.
[0140] Step 3: Establish a Re-Entry Path From the Sub-Intimal Plane
Into the Vessel True Lumen
[0141] This section describes the methods to establish the re-entry
pathway. As each method may apply to various ones of the
embodiments herein, numerous combinations of method/catheter
platform are presented.
[0142] Method 1 Under Step 3: Cutting Sub-Intimal Tissue (FIGS.
1-3) This method describes the cutting of a pathway through the
sub-intimal tissue into the true lumen. Three embodiments for this
method include a catheter shaft with a nosecone termination which
houses the visualization element (Step 1, Methods 1-4) and the
cutting member as shown in the referenced figures, and further
described below. The nosecone has a sideport opening which allows
for visualization of the vascular area (per Step 1, Methods 1
through 4) and identification of the orientation of the vessel true
lumen. Fluoroscopic features of the nosecone can also be used in
conjunction with the primary visualization method to facilitate
alignment to the true lumen. The nosecone also has a distal end
port that allows the catheter to be tracked in a co-linear fashion
over a conventional guide wire to the chosen vascular site.
[0143] Contained within the outer shaft is an internal shaft to
which a distal cutting element is attached. The catheter outer
shaft and the internal shaft may be fabricated using any number of
methods know in the art. An example would be polymer lamination
onto a stainless steel braided tube. Alternatively, either shaft
may be fabricated as described in U.S. patent application Ser. No.
09/984,498, filed Oct. 16, 2001. The cutting member may be
fabricated starting with a stainless steel hypotube, and forming
the appropriate cutting features, e.g. serrations (FIG. 1), needle
point (FIGS. 2 and 3), or a sharpened conical termination (not
shown). The cutting features may be formed using standard machining
methods or electronic discharge machining (EDM).
[0144] Representative dimensions of a cutting element may range
from approximately 0.030 to 0.040 inches in diameter. The nosecone
may be fabricated of similar materials, using similar fabrication
methods.
[0145] FIG. 29 is a flow diagram for cutting through sub-intimal
tissue into a true lumen, under an embodiment. Procedurally, prior
to introducing the catheter into the vasculature, the imaging
element is removed from the catheter. The inner shaft/cutting
element is first positioned such that it covers the nosecone
sideport. For the embodiments of FIGS. 1 and 2, the cutting element
is advanced fully distal such that the distal termination of the
cutting element is "garaged" within the distal receiving section of
the nosecone. In the embodiment of FIG. 3, the cutting element is
rotated until it is positioned opposite the nosecone sideport,
e.g., the sideport is covered by the wall of the hypotube opposite
the cutting feature. In these configurations, the cutting element
covers the nosecone sideport and presents an uninterrupted surface
that can be effectively tracked through the vasculature. The
catheter may then be introduced onto a guide wire and tracked to
the appropriate vascular location.
[0146] Once the vascular site has been reached, the guide wire is
removed and the imaging element is introduced and advanced until it
is positioned at the nosecone sideport. The cutting element is
retracted, exposing the sideport. The imaging element is activated
and the sideport is rotationally positioned towards the vessel true
lumen. Vacuum is applied to the interior of the catheter outer
shaft per Step 2, Method 2, thus beginning the process to
invaginate the sub-intimal tissue into the nosecone sideport. While
confirming that the sideport remains directed towards the vessel
true lumen, the imaging element is retracted, allowing more space
for the sub-intimal tissue to further invaginate into the nosecone
sideport. Note that under this configuration, visualization of the
vessel true lumen is no longer possible since the imaging element
is retracted proximal to the sideport. While maintaining vacuum,
the cutter is then advanced, distally for the embodiments of FIGS.
1 and 2, and proximally for the embodiment of FIG. 3. In the
embodiment of FIG. 1, the cutting element may also be rotated to
facilitate the cutting action. In this process, the actuation of
the cutting element mechanically traps and compresses the tissue
within the sideport, allowing the cutting features to propagate an
incision through the sub-intimal tissue, and through to the vessel
true lumen.
[0147] Note that an alternative to the process described above is
to not retract the visualization element prior to the cutting
action. Thus the visualization element is postioned at the nosecone
sideport, and cutting is performed while simultaneously viewing the
alignment to the vessel true lumen. Also note that in this
alternative technique, the presence of the visualization element in
the nosecone prevents maximum invagination of tissue into the
nosecone. Thus the first technique allows cutting through thicker
sub-intimal tissue which separates the sub-intimal plane from the
vessel true lumen.
[0148] Upon establishment of a pathway into the vessel true lumen,
the vacuum still applied at the nosecone will aspirate blood from
the vessel true lumen, through the pathway in the sub-intimal
tissue and into the catheter shaft, ultimately reaching the
proximal end of the catheter. The vacuum will also be lost. These
two events would indicate that a pathway has been successfully
established into the vessel true lumen.
[0149] Once a pathway has been established into the vessel true
lumen, the imaging element is removed, the cutting element is once
again positioned to cover the nosecone sideport, and a guide wire
is advanced through the catheter to exit the nosecone endport. The
guide wire is thus manipulated through the pathway into the vessel
and the catheter is removed from the vasculature.
[0150] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.060 to 0.070 inches; cutting element outside diameter is
approximately 0.040 to 0.050 inches; and imaging element outside
diameter is as described above.
[0151] Method 2 Under Step 3: Piercing (FIGS. 8 and 9)
[0152] This method describes the general piercing of a pathway
through the sub-intimal tissue into the true lumen. This can be
approached under a first embodiment where the sub-intimal tissue is
held onto the surface of the catheter via vacuum (FIG. 9), or under
a second embodiment where the sub-intimal tissue is invaginated
into the catheter via vacuum (FIG. 8). These two embodiments are
now described.
[0153] Embodiment 1 (Method 2 Under Step 3) (FIG. 9)
[0154] This embodiment includes a nosecone or molded catheter
termination attached to the distal end of the catheter, and an
internal slidably disposed actuating cannula.
[0155] The catheter shaft may be any of a number of catheter shafts
known in the art. The nosecone includes a side exit port and a
distal end port coupled via a slot which, and as will be described
below, allows the guide wire to move from the side port into the
distal end port when the catheter is retracted proximally over the
guide wire. The cannula is guided out of the nosecone sideport via
two internal exit ramps, one on either side of the cannula. The
distal end port of the nosecone allows the catheter to be tracked
in a co-linear fashion over a standard coronary guide wire.
[0156] FIG. 30 is a flow diagram for piercing a pathway through
sub-intimal tissue into a vessel true lumen under an embodiment.
Procedurally, a guide wire is placed in the sub-intimal space of
the target vasculature such that the guide wire distal end is
located distal to the occluded area of the vessel. The cannula is
retracted to a position proximal to the exit ramp so that the
cannula exit port is co-linear with the inner diameter of the
nosecone. This configuration allows the proximal end of the guide
wire to be passed through the nosecone distal end port. The
cannula, the catheter shaft, and thus the catheter may be tracked
over the guide wire to the vascular site.
[0157] The catheter is then aligned to the vessel true lumen. This
is accomplished per Step 1, Methods 1 through 4, or Step 1, Method
5. FIG. 9 illustrates both configurations. In the case using Step
1, Methods 1 through 4, the guide wire is retracted from the
catheter, and the visualization element is advance into the
nosecone. The element is activated at the nosecone side port and
the side port is rotated to face the vessel true lumen. The
visualization element is removed, and the cannula and guide wire
are re-introduced.
[0158] In the case using Method 5, the side port is rotated to face
the vessel true lumen per fluoroscopic visualization.
[0159] The distal tip of the guide wire is now positioned
approximately 2 centimeters (cm) proximal from the distal tip of
the nosecone. At this point the application of vacuum as described
in Step 2, Method 1 can be used to evacuate fluid from the
sub-intimal plane and lock the sub-intimal tissue onto the surface
of the nosecone.
[0160] Next, the cannula is advanced distally and guided out of the
nosecone sideport via the internal exit ramps to pierce the
sub-intimal tissue and gain access to the vessel true lumen. Once
the vessel true lumen is accessed, the cannula remains in place
while the guide wire is advanced into the true lumen. The cannula
may then be retracted into the catheter and resume its original
position. The cannula may have various distal terminations, e.g.
needle shaped, sharpened conical shaped, or circular serrations.
The angle of the internal ramp can vary from approximately 30 to 80
degrees, but is not limited to these angles.
[0161] Lastly, the guide wire is held in position while the
catheter is removed. As the catheter is retracted proximally over
the guide wire, the floppy distal end of the guide wire may be able
to pass through the nosecone side port. However, as the nosecone
reaches the stiff mid and proximal sections of the guide wire, the
guide wire falls through the slot connecting the side port with the
end port. Therefore, as the catheter nosecone is retracted over the
mid and proximal sections of the guide wire, it does so with the
guide wire traveling through the nosecone distal port.
[0162] Typical dimensions of the catheter components are as
follows: outer shafunosecone outside diameter is approximately
0.050 to 0.060 inches; cannula element outside diameter is
approximately 0.020 to 0.030 inches.
[0163] Embodiment 2 (Method 2 Under Step 3) (FIG. 8)
[0164] This embodiment includes: a nosecone or molded catheter
termination attached to the distal end of the catheter lumen which
houses the visualization element (Step 1, Methods 1 through 4); a
lumen which houses either a guide wire or the piercing element;
lumens for vacuum ports; and optional forceps to physically secure
the sub-intimal tissue.
[0165] The nosecone has a side port opening which allows for
visualization of the vascular area (per Step 1, Methods 1-4) and
identification of the orientation of the vessel true lumen. It also
has an end port for tracking over a guide wire. Fluoroscopic
features of the nosecone may also be used in conjunction with the
primary visualization method to facilitate alignment to the true
lumen. The nosecone also has a distal end port that allows the
catheter to be tracked in a co-linear fashion over a conventional
guide wire to the chosen vascular site.
[0166] The catheter shaft may be any of a number of catheter shafts
known in the art. An example includes polymer lamination onto a
stainless steel braided tube. Alternatively, the shafts may be
fabricated as described in U.S. patent application Ser. No.
09/984,498, filed Oct. 16, 2001. The nosecone may be
fabricated/machined from stainless steel and EDM methods.
[0167] FIG. 31 is a flow diagram for piercing a pathway through
sub-intimal tissue into a vessel true lumen, under an alternative
embodiment. Procedurally, a guide wire is placed in the sub-intimal
space of the target vasculature such that the guide wire distal end
is located distal to the occluded area of the vessel. The pierce
element is removed from the catheter, and the forceps (optional)
are retracted to within the nosecone. The catheter is loaded onto
the guide wire and tracked to the vascular site. The guide wire is
removed. The pierce tool may be loaded into the catheter and the
distal tip positioned just proximal to the nosecone sideport. The
visualization element is activated and the sideport is directed
towards the vessel true lumen.
[0168] Next, vacuum is applied to the vacuum lumens per Step 2,
Method 2 thus beginning the process to invaginate the sub-intimal
tissue into the nosecone sideport. While confirming that the
sideport remains directed towards the vessel true lumen, the
skewers/forceps may be advanced thereby further securing the
sub-intimal tissue per Step 2, Method 3.
[0169] The imaging element is then retracted, allowing more space
for the sub-intimal tissue to further invaginate into the nosecone
sideport. Note that under this configuration, visualization of the
vessel true lumen is no longer possible since the imaging element
is retracted proximal to the sideport.
[0170] Next, while maintaining vacuum, the pierce tool is advanced
to pierce a pathway through the sub-intimal tissue, and through to
the vessel true lumen. The pierce element is one of two fundamental
types: including a lumen for a guide wire; and without a lumen.
Each pierce element can have a variety of distal terminations,
e.g., needle shaped, sharpened conical shaped or circular
serrations around the outer diameter.
[0171] When using the pierce element without a lumen, once the
pierce element has pierced a pathway across the sub-intimal tissue,
it is retracted and removed from the catheter, and a guide wire
introduced into the same catheter lumen and advanced through the
sub-intimal tissue, and into the vessel true lumen.
[0172] When using the pierce element with an end lumen, once the
pierce element has pierced a pathway across the sub-intimal tissue,
its distal position is maintained within the vessel true lumen
while a guide wire is advanced through the pierce element lumen.
The guide wire exits the distal end of the pierce element and
enters the vessel true lumen. The pierce element is then retracted
fully into the nosecone.
[0173] For procedures using a pierce tool having a side lumen,
after piercing, the guide wire is passed through the side port and
into the vessel true lumen. The pierce tool is not retracted, and
the catheter is removed over the guide wire.
[0174] Note that an alternative to the process described above is
to not retract the visualization element prior to the piercing
action. Thus the visualization element is positioned at the
nosecone side port, and piercing is performed while simultaneously
viewing the alignment to the vessel true lumen. Also note that in
this alternative technique, the presence of the visualization
element in the nosecone prevents the maximum invagination of tissue
into the nosecone. Thus the first technique allows cutting through
thicker sub-intimal tissue which separates the sub-intimal plane
from the vessel true lumen.
[0175] Once a pathway is established into the vessel true lumen,
the vacuum still applied at the nosecone aspirates blood from the
vessel true lumen through the pathway in the sub-intimal tissue and
into the catheter shaft, ultimately reaching the proximal end of
the catheter. Further, the vacuum is lost. These two events may
indicate that a pathway has been successfully established into the
vessel true lumen. Once a pathway is established the guide wire is
advanced into the true lumen, and the guide wire is held in
position while the catheter is removed.
[0176] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.050 to 0.060 inches; pierce element outside diameter is
approximately 0.010 to 0.015 inches; and the imaging element
outside diameter is as described in Step 1 above.
[0177] Method 3 Under Step 3: Guidewire (FIGS. 4, and 7 through
15)
[0178] This method describes a catheter system which facilitates
the use of either a conventional guide wire or specialized guide
wire to establish a pathway across the sub-intimal tissue. The
guide wire may be specially designed with a tip configuration that
contains minute cutting members, or flutes, or the tip may be
processed to provide an abrasive surface. In either case, these tip
surface features would cut or abrade a pathway through the
sub-intimal tissue.
[0179] Micro-machining methods to fabricate the flutes or cutting
features may include laser machining, electric discharge machining
(EDM), or high-precision conventional machining. An abrasive tip
surface may be fabricated using a micro-abrasive blaster using
abrasive materials such as titanium oxide, or sodium bicarbonate.
Very small abrasive features may also be laser machined on to the
surface of the guide wire tip by the use of an Excimer laser in
combination with a de-focusing mask. The de-focusing mask is a flat
sheet fabricated from metal or other appropriate material, designed
with a pattern of holes and/or slits or other shapes, which is
placed between the laser light and the guide wire tip. This pattern
is reduced in size and ablated onto the surface of the guide wire
tip by the laser light that passes through the mask.
[0180] Note that these specialized guide wire tips are designed to
cut or abraid a pathway through sub-intimal tissue when
agitated/rotated and used in conjunction with the re-entry
catheter, yet once introduced into the vessel true lumen, would not
have the ability to exit into an extra-vascular space.
[0181] Embodiment 1 (Method 3 Under Step 3) (FIG. 4)
[0182] A first embodiment includes a distal nosecone and dual lumen
catheter shaft. One lumen of the catheter shaft houses the imaging
element, per Step 1, Methods 1-4, and the other lumen houses the
guide wire.
[0183] FIG. 32 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under an embodiment. Procedurally, the visualization element
is removed from the catheter, and using this lumen the catheter is
tracked over a guide wire to the desired sub-intimal location.
[0184] Once the catheter is properly advanced in the sub-intimal
plane, the guide wire is removed and the visualization element is
advanced to the distal end of the nosecone. The visualization
element is activated and the catheter is properly aligned to the
vessel true lumen. Note that the pathway of the visualization
element to the tissue may be through the shaft material itself. In
the case of IVUS, this type of visualization may "see" through
HDPE, and thus this is the preferred material for the dual lumen
shaft for the visualization element lumen and the guide wire lumen.
Alternatively, other visualization methods, e.g. Doppler, fiber
optic, OCT may require a "window" through the visualization lumen
to view the tissue.
[0185] Vacuum may be applied per Step 2, Method 1, evacuating the
dissection plane and locking the sub-intimal tissue on the surface
of the catheter. The guide wire is then pushed, and/or rotated to
allow the guide wire distal tip to establish a pathway through the
sub-intimal tissue and into the vessel true lumen. Lastly, while
maintaining the guide wire position, the catheter is retracted and
removed from the vasculature.
[0186] Typical dimensions of the catheter components are: outer
shaft/nosecone outside diameter is approximately 0.050 to 0.070
inches; specialized guide wire outside diameter is approximately
0.010 to 0.018 inches; imaging element outside diameter is as
described in Step 1 above.
[0187] Embodiment 2 (Method 3 Under Step 3) (FIGS. 7 and 8)
[0188] This embodiment includes a distal nosecone and a multiple
lumen catheter shaft that houses a visualization element per Step
1, Methods 1 through 4, a specialized guide wire, and optional
separate vacuum ports.
[0189] FIG. 33 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a first alternative embodiment. Prior to the
introduction of the catheter into the vasculature, the specialized
guide wire is removed. Using this same lumen, the catheter is
tracked over a guide wire to the desired sub-intimal location. Once
the catheter is properly advanced in the sub-intimal plane, the
guide wire is removed and replaced by the specialize guide
wire.
[0190] The visualization element is activated and the catheter is
properly aligned to the vessel true lumen. Vacuum may be applied
per Step 2, Method 2, evacuating the dissection plane and
invaginating the sub-intimal tissue into the catheter. Note that
vacuum may be applied through the guide wire lumen, the
visualization element lumen, or through optional vacuum ports as
shown in FIG. 7. At this point, the visualization element may be
retracted proximally into the catheter shaft, adding more room for
the sub-intimal tissue to be invaginated into the nosecone. This
may be desired in the case that the sub-intimal tissue is thick,
and requires a deeper purchase in order to create a pathway into
the vessel true lumen. Note FIG. 8 is a similar embodiment which
shows optional forceps or skewers to hold the sub-intimal
tissue.
[0191] Next, the guide wire is pushed, and/or rotated to allow the
guide wire distal tip to establish a pathway through the
sub-intimal tissue and into the vessel true lumen. While
maintaining the guide wire position, the catheter is retracted and
removed from the vasculature.
[0192] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.050 to 0.060 inches; specialized guide wire outside diameter is
approximately 0.010 to 0.018 inches; imaging element outside
diameter is as described in Step 1 above.
[0193] Embodiment 3 (Method 3 Under Step 3) (FIG. 9)
[0194] This embodiment includes a nosecone or molded catheter
termination attached to the distal end of the catheter, and an
internal slidably disposed actuating cannula. The catheter shaft
may be any of a number of catheter shafts known in the art. The
nosecone includes a side exit port and a distal end port coupled
via a slot which, and as will be described later, allows the guide
wire to move from the side port into the distal end port when the
catheter is retracted proximally over the guide wire. The cannula
is guided out of the nosecone side port via internal exit ramps.
The angle of the internal ramp is from approximately 30 degrees to
80 degrees, but not necessarily limited to these angles. The distal
end port of the nosecone allows the catheter to be tracked in a
co-linear fashion over a standard coronary guide wire.
Representative dimensions are as follows: side port width is
approximately 0.027 inches; slot width and distal port widths are
approximately 0.016 inches; cannula outside diameter is
approximately 0.025 inches; and cannula inside diameter is
approximately 0.016 inches. Note that the internal ramp is the same
width as the side port.
[0195] FIG. 34 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a second alternative embodiment. Procedurally, a guide
wire is placed in the sub-intimal space of the target vasculature
such that the guide wire distal end is located distal to the
occluded area of the vessel. The cannula is retracted to a position
proximal to the exit ramp so that the cannula exit port is
co-linear with the inner diameter of the nosecone. This
configuration allows the proximal end of the guide wire to be
passed through the nosecone distal end port, the cannula and the
catheter shaft, and thus the catheter may be tracked over the guide
wire to the vascular site.
[0196] The catheter is then aligned to the vessel true lumen. This
may be accomplished per Step 1 Methods 1-4, or Step 1, Method 5. In
the case where Methods 1-4 are used, the guide wire (and optionally
the cannula) is retracted from the catheter, and the visualization
element is advance into the nosecone. The element is activated at
the nosecone sideport and the side port is rotated to face the
vessel true lumen. The visualization element is removed, and the
cannula and guide wire are re-introduced. When Method 5 is used,
the side port is rotated to face the vessel true lumen per
fluoroscopic visualization.
[0197] The distal tip of the guide wire is now positioned
approximately 2 centimeters proximal from the distal tip of the
nosecone. At this point the application of vacuum as described in
(Step 2, Method 1) may be used to evacuate fluid from the
sub-intimal plane and lock the sub-intimal tissue onto the surface
of the nosecone.
[0198] Next, the cannula is advanced distally and guided through
the internal ramp until it is brought into secure purchase with the
sub-intimal tissue. The guide wire is then advanced until the tip
is coincident with the cannula distal tip, such that both are in
contact with the sub-intimal tissue. Utilizing the combined effects
of the vacuum and the slight extension of the cannula against the
sub-intimal tissue, the guide wire is then rotated and pushed to
initiate a pathway through the sub-intimal tissue.
[0199] After a re-entry pathway has been formed, the cannula is
advanced into the true lumen, the RF system removed, and a
conventional guide wire is placed into the true lumen.
Alternatively, the cannula may remain retracted in the nosecone,
and the guide wire fed directly through the pathway in the
sub-intimal tissue and into the true lumen.
[0200] After the guide wire has been advanced into the vessel true
lumen, the cannula may then be retracted into the catheter and
resume its original position.
[0201] The position of the guide wire is maintained in the vessel
true lumen, and the entire catheter system is retracted from the
vasculature. As the catheter is retracted proximally over the guide
wire, the floppy distal end of the guide wire may be able to pass
through the nosecone side port, however as the nosecone reaches the
stiff mid and proximal sections of the guide wire, the guide wire
must now fall through the slot connecting the side port with the
end port. Therefore, as the catheter nosecone is retracted over the
mid- and proximal sections of the guide wire, it does so with the
guidewire traveling through the nosecone distal port.
[0202] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.050 to 0.060 inches; cannula element outside diameter is
approximately 0.020 to 0.030 inches; and specialized guide wire
outside diameter is approximately 0.010 to 0.018 inches.
[0203] Embodiment 4 (Method 3 Under Step 3) (FIG. 10)
[0204] This embodiment includes a catheter having a nosecone or
molded distal termination, a single lumen catheter shaft, and a
specialized guide wire to be used specifically with the catheter.
This guide wire will be described in detail later. The catheter
shaft may be any of a number of catheter shafts known in the art.
The nosecone is similar to the nosecone of FIG. 9 in that it
includes a side exit port and a distal end port coupled via a slot.
However, the dimensions of these features are peculiar to this
design.
[0205] As previously stated, the nosecone of FIG. 10 is similar to
that of FIG. 9 with the exception that the width of the side port
and the outside diameter of the end port are slightly larger than
the width of the connecting slot. As example dimensions, the width
of the side port and the outside diameter of the end port may be
approximately 0.016 inches, and the slot may be approximately 0.012
inches. The significance of these dimensions will become evident
once the guide wire is dimensionally described. The internal ramp
has a width approximately equal to the size of the side port. The
angle of the internal ramp may also vary from approximately 30
degrees to 80 degrees, but is not necessarily limited to these
angles. The distal end port of the nosecone allows the catheter to
be tracked in a co-linear fashion over the specialized guide
wire.
[0206] The guide wire may be fabricated using standard methods and
materials known by those skilled in the art. The outside diameter
over the distal most 5-8 centimeters may be approximately 0.014
inches, followed proximally by a 1-2 centimeter portion with an
outside diameter of approximately 0.010 inches, followed proximally
by the remainder of the guide wire with an outside diameter of
approximately 0.014 inches.
[0207] FIG. 35 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a third alternative embodiment. Procedurally, the
catheter is tracked over a standard guide wire, or over the
specialized guide wire, either of which has been placed in the
desired sub-intimal space of the target vasculature. If a standard
guide wire is initially used, it may then be removed and the
specialized guide wire advanced into the catheter.
[0208] Next, the catheter must be aligned to the vessel true lumen.
This may be accomplished per Step 1 Methods 1-4, or Step 1, Method
5. In the case where Methods 1-4 are used, the guide wire is
retracted from the catheter, and the visualization element is
advance into the nosecone. The element is activated at the nosecone
sideport and the side port is rotated to face the vessel true
lumen. The visualization element is removed, and the specialized
guide wire is re-introduced. In the case that Method 5 is used, the
side port is rotated to face the vessel true lumen per fluoroscopic
visualization.
[0209] Next, the distal tip of the specialized guide wire is
positioned approximately 2 centimeters proximal from the distal tip
of the nosecone. At this point the application of vacuum as
described in (Step 2, Method 1) may be used to evacuate fluid from
the sub-intimal plane and lock the sub-intimal tissue onto the
surface of the nosecone.
[0210] The specialized guide wire is now advanced distally. Note
that because the nosecone exit port is co-incident with the
catheter lumen, the natural tendency of the specialized guide wire
may be for it to simply pass out the distal port of the nosecone.
The intent, however is to advance the specialized guide wire out of
the nosecone side port. This issue is easily resolved. Prior to the
introduction of any guide wire into the vasculature, the physician
routinely places a small curve on the end of the guide wire to
facilitate negotiating the tortuosity in the vasculature.
Therefore, the specialized wire need only be rotated until the
curved distal portion of the wire engages the internal rails. It
may then be advanced onto the internal ramp of the side port.
[0211] The distal 5-8 centimeters of the specialized guide, at a
width of approximately 0.014 inches, will advance on the two rails
of the internal ramp, since the rails are separated by the
0.012-inch width of the slot, and the side port is 0.016 inches
wide. The specialized guide wire is brought into contact with the
sub-intimal tissue. Utilizing the effect of the vacuum, the
specialized guide wire can be rotated and pushed to initiate a
pathway through the sub-intimal tissue.
[0212] After the specialized guide wire has crossed to the vessel
true lumen, the wire is advanced further distally. In this process,
the 5-8 centimeters of distal length guide wire (0.014 inches
outside diameter) continues to advance over the internal rails,
until the 1 centimeter section of guide wire (0.010 inches outside
diameter) reaches the distal edge of the ramp. At this point the
section of guide wire having a 0.010 inch outside diameter falls
through the 0.012-inch wide slot and into the 0.016-inch wide
distal end port.
[0213] At this point, the distal 6-9 centimeters of the guide wire
is across the sub-intimal plane and into the vessel true lumen.
While maintaining the wire position in the vasculature, the
catheter may now be retracted proximally along the wire, because
the nosecone end port is 0.016 inches in diameter, and the proximal
portion of the wire is 0.014 inches in diameter.
[0214] Typical dimensions of the catheter components are as
follows: outer shafunosecone outside diameter is approximately
0.030 to 0.050 inches; specialized guide wire outside diameter is
as described above.
[0215] Embodiment 5 (Method 3 Under Step 3) (FIG. 11)
[0216] This embodiment includes a catheter having a simple nosecone
or molded distal termination, and a single lumen catheter shaft.
The catheter shaft may be any of a number of catheter shafts known
in the art. The nosecone includes an internal ramp connecting the
catheter lumen with a single side exit port. This embodiment has no
distal port to track over a guide wire. This catheter can be used
in conjunction with a conventional guide wire, or a specialized
guide wire as described at the end of this section.
[0217] FIG. 36 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a fourth alternative embodiment. Procedurally, the
catheter is tracked over a standard guide wire which has been
placed in the desired sub-intimal space of the target vasculature.
Note that since the guide wire emerges laterally from the nosecone,
the very tip of the catheter will track eccentrically over the
guide wire.
[0218] Next, the catheter is aligned to the vessel true lumen. This
may be accomplished per Step 1 Methods 1-4, or Step 1, Method 5.
FIG. 11 shows both configurations. In the case of Methods 1-4, the
guide wire is retracted from the catheter, and the visualization
element is advanced into the nosecone. The element is activated at
the nosecone side port and the side port is rotated to face the
vessel true lumen. The visualization element is removed, and the
guide wire is re-introduced. In the case of Method 5, the side port
is rotated to face the vessel true lumen per fluoroscopic
visualization.
[0219] Next, the distal tip of the guide wire is.positioned
approximately 2 centimeters proximal from the distal tip of the
nosecone. At this point the application of vacuum as described in
(Step 2, Method 1) may be used to evacuate fluid from the
sub-intimal plane and lock the sub-intimal tissue onto the surface
of the nosecone. Vacuum is translated to the nosecone via the
single shaft lumen.
[0220] The guide wire is then advanced distally into the nosecone.
The guide wire is brought into contact with the sub-intimal tissue
at the nosecone side port at an angle determined by the exit ramp
of the nosecone. The wire is then rotated and pushed in order to
initiate and propagate a pathway through the sub-intimal tissue.
The angle of the internal ramp may vary from approximately 30
degrees to 80 degrees, but is not necessarily limited to these
angles.
[0221] After the guide wire has successfully been advanced into the
vessel true lumen, the guide wire position is maintained and the
catheter may be retracted proximally over the guide wire and
removed from the vasculature.
[0222] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; specialized guide wire outside diameter is
approximately 0.010 to 0.018 inches.
[0223] Embodiment 6 (Method 3 Under Step 3) (FIG. 12)
[0224] This embodiment includes a catheter having a nosecone or
molded distal termination, a single lumen catheter shaft, and an
internal slidably disposed tube the distal end of which translates
within the catheter nosecone. The distal end of the push tube or
member is slidably disposed within the nosecone. Upon actuation of
the push member in a distal direction, a percentage of the proximal
section of the nosecone side port is covered. The percentage of
coverage is controlled by a distal stop within the nosecone that
limits the distal translation of the internal sliding member or
tube. In the case the internal sliding member is a tube, the
internal sliding member becomes the guide wire lumen.
[0225] As the internal sliding member is advanced into this distal
position, it reduces the effective length of the nosecone side
port. This forces the guide wire to exit the side port at a more
acute angle that is more normal to the axis of the catheter, and
more normal to the sub-intimal tissue plane. The exit angle of the
guide wire is governed by the proximal contact point against the
internal sliding member, and the distal contact point against the
exit ramp of the nosecone. The greater acute angle allows the guide
wire to produce more force normal to the sub-intimal tissue
surface, and improves the ability of the wire to establish a
pathway across the sub-intimal tissue.
[0226] FIG. 37 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a fifth alternative embodiment. Procedurally, the
sliding tube may remain in the catheter at all times. In
preparation of the catheter and during delivery of the catheter to
the vascular site, the tube is retracted just proximal to the
nosecone. Prior to the advancement of the guide wire out of the
nosecone sideport, the sliding tube is advance to its distal most
position, thus reducing the effective length of the nosecone
sideport.
[0227] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; internal slide tube outside diameter is
approximately 0.020 to 0.030 inches; and specialized guide wire
outside diameter is approximately 0.010 to 0.018 inches.
[0228] Embodiment 7 (Method 3 Under Step 3) (FIG. 13)
[0229] FIG. 13 is a diagram of a single lumen catheter shaft,
terminated in a "J" tip, used in conjunction with a conventional or
specialized guide wire. The "J" tip configuration of the catheter
is designed to be torqued into position within the sub-intimal
plane and directed towards the sub-intimal tissue. The guide wire
is directed at an angle normal to the sub-intimal tissue, which
improves the ability of the wire to establish a pathway across the
sub-intimal tissue.
[0230] The "J" termination of the catheter can be fluoroscopically
visible to facilitate the positioning process in the sub-intimal
plane. This type of termination may be easily fabricated or molded
from fluoroscopically visible materials such as platinum coils or
gold coated stainless steel coils laminated with a variety of
polymers, e.g. nylons, HDPE, or Pebax. The "J" tip is designed to
straighten in order to track over a guide wire to the vascular
site, yet re-form its shape when positioned in the vasculature, and
the guide wire is retracted. A visualization window may be
incorporated just proximal to the "J" tip to be used in conjunction
with an on-board visualization technique, per Step 1, Methods 1-4.
For the use of IVUS, for example, this window may be fabricated
from HDPE.
[0231] FIG. 38 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a sixth alternative embodiment. Procedurally, a guide
wire is positioned in the sub-intimal space.
[0232] The distal end of the catheter is loaded onto the guide
wire. In this process the "J" tip is straightened as it tracks over
the wire and to the sub-intimal site. Once the terminal end of the
catheter has reached the desired location, the guide wire is
retracted, allowing the "J" tip to re-form.
[0233] The catheter is now aligned to the vessel true lumen. This
may be accomplished per Step 1 Methods 1-4, or Step 1, Method 5.
FIG. 13 shows both configurations. In the case of Methods 1-4, the
guide wire is retracted from the catheter, and the visualization
element is advanced to the visualization window. The visualization
element is activated at the window and the "J" tip is rotated to
face the vessel true lumen. The visualization element is removed,
and the guide wire is re-introduced. In the case of Method 5, the
side port is rotated to face the vessel true lumen per fluoroscopic
visualization.
[0234] Next, vacuum may be applied through the catheter lumen per
Step 2, method 1 to evacuate the sub-intimal plane. The guide wire
is then advanced until it is brought into contact with the
sub-intimal tissue. Procecturally, the wire is then pushed or
rotated as required in order to initiate and propagate a pathway
through the sub-intimal tissue and into the vessel true lumen. Once
the guide wire has established a pathway through the sub-intimal
tissue, the wire position is maintained, and the catheter is
retracted, leaving the distal portion of the wire positioned in the
vessel true lumen.
[0235] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; specialized guide wire outside diameter is
approximately 0.010 to 0.018 inches.
[0236] Embodiment 8 (Method 3 Under Step 3) (FIG. 14)
[0237] This embodiment includes a catheter having a nosecone or
molded distal termination, an internal push-ramp which is actuated
by an internal push tube or member, and a single lumen catheter
shaft. The push ramp may be constructed of a flexible metal such as
Nitinol or spring steel, or a polymer such as nylon or PEEK, any of
which fabricated with or without appropriate detents to allow for
bending, as required. The distal end of the push ramp is connected
or hinged in some fashion about the internal distal termination of
the catheter shaft, opposite the side port. When the push tube or
member is fully retracted proximally, the push ramp assumes a
linear configuration, lying essentially flat against the inside
wall of the catheter, opposite the nosecone side port. When the
push tube or member is advanced distally, the push ramp forms an
incline that leads from the proximal end of the ramp, opposite the
nosecone side port, to the distal end of the side port. This ramp
will re-direct the guide wire out of the nosecone side port as it
is advanced distally in the catheter.
[0238] This catheter system may be used with any of the
visualization techniques of Step 1.
[0239] FIG. 39 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a seventh alternative embodiment. Procedurally, a
guide wire is positioned in the sub-intimal space. The pull tube or
member is retracted proximally, and the distal end of the catheter
is loaded onto the guide wire. Once the terminal end of the
catheter has reached the desired location, the guide wire is
retracted just proximal to the proximal portion of the ramp.
[0240] The catheter is aligned to the vessel true lumen. This may
be accomplished per Step 1 Methods 1-4, or Step 1, Method 5. FIG.
13 shows both configurations. In the case of Methods 1-4, the guide
wire is retracted from the catheter, and the visualization element
is advanced to the visualization window. The visualization element
is activated at the nosecone sideport and the sideport is rotated
to face the vessel true lumen. The visualization element is
removed, and the guide wire is re-introduced. In the case of Method
5, the side port is rotated to face the vessel true lumen per
fluoroscopic visualization.
[0241] Next, vacuum may be applied through the catheter lumen per
Step 2, method 1 to evacuate the sub-intimal plane. The push tube
or member is then advanced distally to urge the push ramp into its
hinged configuration. The guide wire is then advanced distally,
following the ramp to the nosecone cone port until it is brought
into contact with the sub-intimal tissue. Procedurally, the wire is
then pushed or rotated as required in order to initiate and
propagate a pathway through the sub-intimal tissue and into the
vessel true lumen. Once the guide wire has established a pathway
through the sub-intimal tissue, the wire position is maintained and
the catheter is retracted, leaving the distal portion of the wire
positioned in the vessel true lumen.
[0242] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; internal push tube outside diameter is
approximately 0.020 to 0.030 inches; and specialized guide wire
outside diameter is approximately 0.010 to 0.018 inches.
[0243] Embodiment 9 (Method 3 Under Step 3) (FIG. 15)
[0244] This embodiment includes a dual lumen catheter shaft
terminating in a single lumen "J" tip, and is used in conjunction
with a conventional or specialized guide wire. This dual lumen
catheter has the same "J" type single lumen distal termination as
described in Method 3, Embodiment 7, with the exception that it
transitions proximally to a dual lumen catheter shaft. Fabrication
and materials for the "J" tip are as stated in Method 3, Embodiment
7. The dual lumen catheter shaft may be fabricated using standard
materials and methods known to those skilled in the art. Only one
of the slidably disposed elements contained within either lumen can
be advanced individually into the "J" tip single lumen, as required
by the procedure. The "J" tip may accommodate only one element at
any time.
[0245] For example, one lumen may contain the guide wire while the
other lumen may be used to deliver various elements to the vascular
site, e.g. visualization elements per Step 1, Methods 1-4, or other
types of re-entry elements such as a wire with a stiff distal tip
which could be used only to pierce a hole through the sub-intimal
tissue, but would be too stiff to be advanced into the vessel true
lumen.
[0246] FIG. 40 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under an eighth alternative embodiment. In a first scenario,
the first lumen of the dual lumen contains a standard guide wire
and the second lumen contains a re-entry wire or re-entry element
to pierce or otherwise establish a pathway into the vessel true
lumen. Procedurally, one lumen is loaded with a re-entry wire or
element and advanced just proximal to the entrance to the single
distal lumen.
[0247] The distal end of the catheter is then loaded onto a
standard guide wire which has been advanced into a sub-intimal
plane. The catheter is advanced to the desired vascular location,
and the guide wire withdrawn just proximal to the entrance to the
single lumen. The catheter is now aligned to the vessel true lumen.
This embodiment would make use of Step 1, Method 5 to align the
catheter.
[0248] The sub-intimal plane is now evacuated per Step 2, Method 2.
Next, the guide wire or re-entry element is advanced into the "J"
tip and manipulated to establish a pathway through the sub-intimal
plane and into the vessel true lumen. The re-wire or re-entry
element is retracted out of the single lumen. The standard guide
wire may then be advanced into the distal single lumen, and out of
the "J" tip, through the pathway produced in the sub-intimal
tissue, and into the vessel true lumen. Lastly, the guide wire is
held in place while the catheter is retracted proximally and
removed from the vasculature.
[0249] FIG. 41 is a flow diagram for using a guide wire to
establish a pathway through sub-intimal tissue into a vessel true
lumen, under a ninth alternative embodiment. In a second scenario,
the first lumen of the dual lumen contains a visualization element,
per Step 1, Method 1-4, and the second lumen contains a re-entry
wire to establish a pathway into the vessel true lumen.
[0250] Procedurally, one lumen is loaded with the visualization
element and advanced proximal to the entrance to the distal single
lumen. The distal end of the catheter is then loaded onto a
standard guide wire that has been advanced into a sub-intimal
plane. The catheter is advanced to the desired vascular location,
the guide wire is removed from the catheter and replaced with the
re-entry wire. Next the visualization element is advanced into the
distal single lumen within the area of the window for viewing, and
the "J" tip is aligned with the vessel true lumen. The
visualization element is then withdrawn to within the dual lumen
portion of the shaft.
[0251] The sub-intimal plane is now evacuated per Step 2, Method 2.
This is best accomplished through the lumen which houses the
visualization element because the visualization element need not be
translated proximally/distally through the proximal hemostasis seal
for the remainder of the procedure. Next, the re-entry wire is
advanced into the "J" tip and manipulated to establish a pathway
through the sub-intimal tissue and into the vessel true lumen. The
re-entry wire is retracted and replaced with the guide wire, and
the guide wire is held in place while the catheter is retracted
proximally and removed from the vasculature.
[0252] In a third scenario, all steps are similar to the second
scenario, with the exception that a stiff re-entry wire or element
is used to establish the pathway through the sub-intimal tissue,
and is then replaced by a standard guide wire and advanced into the
vessel true lumen before removal of the catheter.
[0253] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; dual lumen shaft is approximately 0.030 to 0.050
inches (each lumen); and specialized guide wire outside diameter is
approximately 0.010 to 0.018 inches.
[0254] Method 4 Under Step 3: Radio Frequency (RF) Energy (FIGS. 5,
6, 7, 9, 11 through 15, and 18)
[0255] This method describes the application of radio frequency
(RF) energy to ablate a select section of sub-intimal tissue to
create a path into the true lumen. The RF energy can be delivered
as continuous with an unspecified duration. Alternatively, the RF
energy may be gated such that it is defined by a pre-determined
duration, e.g., 5-50 milliseconds.
[0256] Two separate modes of application of RF energy may be
employed, unipolar or bi-polar. Both methods may be employed in all
embodiments described herein.
[0257] In a unipolar configuration, a single active electrode (or a
group of common electrodes) is located at a distal position of the
re-entry catheter. The active electrode(s) may be contained on the
outside surface of the catheter, or within the distal nosecone or
distal termination of the catheter, such that a communication path
exists to the outside of the catheter. The placement of the active
electrode(s) is such that when the catheter is aligned to the
vessel true lumen per Step 1, the electrode(s) faces the
sub-intimal tissue to be ablated. A second grounding electrode is
external to the patient and placed against the patient's buttocks.
The surface area of the grounding electrode is very large with
respect to the catheter active electrode.
[0258] As RF energy is applied between the catheter active
electrode(s) and the grounding electrode, a closed circuit is
established from one electrode to the other, through the patients
body tissue. The energy density (RF power) and duration is adjusted
to ablate only the sub-intimal tissue that separates the dissection
plane from the vessel true lumen. As the RF energy travels between
the catheter electrode(s) and the grounding electrode, the energy
density decreases significantly such that immediately peripheral to
the volume of sub-intimal tissue to be ablated, the energy density
is insufficient to affect the surrounding vessel structure or other
body tissues.
[0259] In a bipolar configuration both the active electrode and the
grounding electrode are contained at the distal portion of the
catheter. One or both can be mounted on the outside surface of the
catheter, or within the catheter itself. Both electrodes are
intended to be of similar size, although exact size and
configuration may vary to meet the overall design requirements of
the re-entry catheter system. The placement of the electrodes is
such that when the catheter is aligned to the vessel true lumen per
Step 1, the sub-intimal tissue to be ablated completes the circuit
between electrodes.
[0260] As RF energy is applied between the catheter electrodes, a
closed circuit is established from one electrode to the other,
co-linear with the sub-intimal tissue plane that separates the
dissection plane from the vessel true lumen. The energy density (RF
power) and duration is adjusted to ablate the sub-intimal tissue
that separates the dissection plane from the vessel true lumen.
Unlike the unipolar technique described above, the energy density
between the two bipolar electrodes is relatively constant, and only
the sub-intimal tissue along the path between the two electrodes is
ablated. It is surmised that the bipolar mode may have more
accurate control over tissue ablation than the unipolar
configuration.
[0261] Embodiment 1 (Method 4 Under Step 3) (FIGS. 5 through
7A)
[0262] This embodiment includes a catheter having a nosecone or
molded distal termination, an internal visualization element, and
one or more RF electrodes. In this embodiment the single lumen
catheter shaft is terminated by a formed nosecone having a sideport
for imaging the sub-intimal tissue and locating the vessel true
lumen, and an endport for tracking the catheter over a guide wire.
The nosecone is also shown with one or more RF electrodes, suitable
to embody either the unipolar or bipolar configuration.
[0263] FIG. 42 is a flow diagram for creating a path into a vessel
true lumen using radio frequency (RF) energy, under an embodiment.
Procedurally, the visualization element is removed from the
catheter (FIG. 5 and 6 only), and the catheter is loaded onto a
guide wire that has been advanced into a sub-intimal plane. The
catheter is tracked to the vascular site, and the guide wire is
removed. The visualization element is loaded into the catheter, and
advanced into the nosecone sideport. The visualization element is
activated and the sideport is directed towards the vessel true
lumen.
[0264] Next, vacuum is applied within the catheter lumen per Step
1, Method 1 to secure the sub-intimal tissue to the nosecone, and
bring the sub-intimal tissue into contact with the RF electrodes.
Next, RF energy may be applied to the electrodes as required to
ablate the sub-intimal tissue and form a pathway into the vessel
true lumen.
[0265] If the sub-intimal tissue is thick, it may be advantageous
to invaginate more sub-intimal tissue into the nosecone by
retracting the visualization element and continuously applying
vacuum per Step 2, Method 2. This enhances the likelihood of
ablating the volume of sub-intimal tissue necessary to establish a
pathway into the true lumen.
[0266] As addressed in the beginning of this Method, RF energy may
be applied in the unipolar configuration to one or more of the
electrodes mounted on the catheter, treating the electrodes as a
common pole with respect to the grounding plate. Alternatively, in
the bipolar configuration, the RF signal may be applied to one of
the catheter mounted electrodes, using the other as the ground
return.
[0267] The visualization element is removed (FIG. 5 and 6 only),
and a standard guide wire is introduced either through the nosecone
end port or side port into the vessel true lumen.
[0268] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.040 to 0.060 inches; imaging element outside diameter is as
described in Step 1 above.
[0269] Embodiment 2 (Method 4 Under Step 3) (FIG. 9)
[0270] This embodiment includes a nosecone or molded catheter
termination attached to the distal end of the catheter, an internal
slidably disposed actuating cannula, and an element slidably
disposed in the cannula which contains distal electrodes.
[0271] FIG. 43 is a flow diagram for creating a path into a vessel
true lumen using radio frequency (RF) energy, under a first
alternative embodiment. This embodiment is essentially similar to
that of Method 3, Embodiment 3 with the exception that in place of
the guide wire, an element is delivered inside the cannula which
contains one or more electrodes to ablate the sub-intimal
tissue.
[0272] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; cannula element outside diameter is approximately
0.020 to 0.030 inches; and RF element outside diameter is
approximately 0.015 to 0.020 inches.
[0273] Embodiment 3 (Method 4 Under Step 3) (FIG. 11)
[0274] This embodiment includes a catheter having a simple nosecone
or molded distal termination, a single lumen catheter shaft and an
element slidably disposed in the catheter which contains distal
electrodes.
[0275] FIG. 44 is a flow diagram for creating a path into a vessel
true lumen using radio frequency (RF) energy, under a second
alternative embodiment. Procedurally, this embodiment is
essentially similar to that of Method 3, Embodiment 5 with the
exception that in place of the guide wire, an element is delivered
inside the catheter which contains one or more distal electrodes to
ablate the sub-intimal tissue.
[0276] After a pathway has been established through the sub-intimal
tissue, the slidably disposed element is removed from the catheter,
and a standard guide wire is advanced into the vessel true
lumen.
[0277] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; and RF element outside diameter is
approximately 0.015 to 0.020 inches.
[0278] Embodiment 4 (Method 4 Under Step 3) (FIG. 12)
[0279] This embodiment includes a catheter having a simple nosecone
or molded distal termination, a single lumen catheter shaft, an
internal slidably disposed tube, and an element slidably disposed
in the tube which contains distal electrodes.
[0280] FIG. 45 is a flow diagram for creating a path into a vessel
true lumen using radio frequency (RF) energy, under a third
alternative embodiment. Procedurally, this embodiment is
essentially similar to that of Method 3, Embodiment 6, with the
exception that in place of the guide wire, a slidably disposed
element is used which contains one or more electrodes to ablate the
sub-intimal tissue.
[0281] After a pathway has been established through the sub-intimal
tissue, the slidably disposed element is removed from the catheter,
and a standard guide wire is advanced into the vessel true
lumen.
[0282] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; internal slide tube outside diameter is
approximately 0.020 to 0.030 inches; and RF element outside
diameter is approximately 0.015 to 0.020 inches.
[0283] Embodiment 5 (Method 4 Under Step 3) (FIG. 13)
[0284] This embodiment includes a single lumen catheter shaft,
terminated in a "J" tip, used in conjunction with an element
slidably disposed in the catheter which contains distal electrodes.
Procedurally, this embodiment is used in a similar fashion to
Method 3, Embodiment 7. In this embodiment, and with further
reference to FIG. 38, the slidably disposed element contains one or
more electrodes to ablate the sub-intimal tissue, and takes the
place of the guide wire.
[0285] After a pathway has been established through the sub-intimal
tissue, the slidably disposed element is removed from the catheter,
and a standard guide wire is advanced into the vessel true
lumen
[0286] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; and RF element outside diameter is approximately
0.015 to 0.020 inches.
[0287] Embodiment 6 (Method 4 Under Step 3) (FIG. 14)
[0288] This embodiment includes a catheter having a nosecone or
molded distal termination, an internal push-ramp which is actuated
by an internal push tube or member, an element slidably disposed in
the catheter which contains distal electrodes and a single lumen
catheter shaft.
[0289] Procedurally, this embodiment is used in a similar fashion
to Method 3, Embodiment 8. In this embodiment, and with further
reference to FIG. 39, the slidably disposed element contains one or
more electrodes to ablate the sub-intimal tissue, and takes the
place of the guide wire.
[0290] After a pathway has been established through the sub-intimal
tissue, the slidably disposed element is removed from the catheter,
and a standard guide wire is advanced into the vessel true
lumen
[0291] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; internal push tube outside diameter is
approximately 0.020 to 0.030 inches; and RF element outside
diameter is approximately 0.015 to 0.020 inches.
[0292] Embodiment 7 (Method 4 Under Step 3) (FIG. 15)
[0293] Describes a dual lumen catheter shaft, terminated in a
single lumen "J" tip, used in conjunction with an element slidably
disposed in the catheter which contains distal electrodes.
Procedurally, this embodiment is used in a similar fashion to
Method 3, Embodiment 9. In this embodiment, and with further
reference to FIGS. 40 and 41, the slidably disposed element
contains one or more electrodes to ablate the sub-intimal tissue,
and takes the place of the guide wire.
[0294] After a pathway has been established through the sub-intimal
tissue, the slidably disposed element is removed from the catheter,
and a standard guide wire is advanced into the vessel true
lumen
[0295] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; dual lumen shaft outside diameter is approximately
0.030 to 0.050 inches (each lumen); and RF element outside diameter
is approximately 0.015 to 0.020 inches.
[0296] Method 5 Under Step 3: Laser Energy (FIGS. 4, 7 through 15;
and 17)
[0297] This method describes the application of laser energy to
ablate the sub-intimal tissue that separates the dissection plane
from the vessel true lumen. In the following embodiments, optical
fiber(s) is/are contained within the catheter, such that the
terminal end of the optical fiber(s) is/are positioned to deliver
laser energy to ablate the sub-intimal tissue.
[0298] In the following embodiments, the optical fiber element may
comprise: a single optical fiber contained within a protective
sheath such as polyimide or high density polyethelene; a bundle of
optical fibers collectively protected by a sheath such as
polyimide, or high density polyethelene; or an optical fiber bundle
arranged in an annular fashion, such that the interior of the
bundle is an open lumen sized to accommodate a standard guide wire.
In this embodiment, the optical fibers may be arranged in the
annular fashion within a polymer extrusion. The extrusion design
thus encases the fibers in the annular arrangement, provides a
lumen within the extrusion for the passage of a guide wire, and
provides an outer smooth surface, such that the fiber optic bundle
may be translated within a catheter lumen. These optical fiber
embodiments are shown in FIG. 16.
[0299] Embodiment 1 (Method 5 Under Step 3) (FIG. 4)
[0300] This embodiment includes a distal nosecone or molded shaft
termination and dual lumen catheter shaft. A first lumen of the
catheter shaft houses the imaging element, per Step 1, Method 1-4,
and a second lumen houses the optical fiber system or a guide
wire.
[0301] This embodiment allows simultaneous visualization of the
true lumen and sub-intimal tissue, while delivering laser energy
via the optical fiber system to ablate the sub-intimal tissue. In
operation, small volumes of sub-intimal tissue are sequentially
ablated with each pulsed delivery of optical energy, until a
pathway has been established. The exit angle from the nosecone of
the lumen which houses the optical fiber system is approximately in
the range of 20 degrees to 90 degrees, but is not necessarily
limited to these angles.
[0302] The termination of the optical fiber may be normal to the
axis of the optical fiber, such that the exit angle is zero degrees
with respect to the optical fiber. Alternatively, the termination
of the optical fiber may be angled with respect to the axis to
provide total internal reflection of the light, such that the light
emerges at an angle to the axis of the optical fiber. The angle
termination provides a greater overall exit angle of the laser
light, when combined with the angle by which the optical fiber
exits the corresponding lumen, and provides overall operational
flexibility.
[0303] FIG. 46 is a flow diagram for creating a path into a vessel
true lumen using laser energy, under an embodiment. Procedurally,
prior to introducing the catheter into the vasculature, the optical
fiber system is loaded into a lumen, and the visualization element
is removed from the catheter. Using the visualization lumen, the
catheter is loaded onto a guide wire that has been advanced into a
sub-intimal plane, and the catheter is advanced to the desired
vascular site. In this configuration, the catheter tracks on the
wire in a co-linear fashion.
[0304] The guide wire is next removed from the catheter and the
visualization element is advanced in the same lumen until it is
properly positioned at the distal end of the catheter. The optical
fiber system is advanced until the distal termination is coincident
with the lateral exit port at the nosecone.
[0305] Next, the visualization element is activated and the
catheter is properly aligned to the vessel true lumen. Note that
the pathway from the visualization element to the tissue may be
through the shaft material itself. In the case of IVUS, this type
of visualization may "see" through HDPE, and thus is the preferred
material for the dual lumen shaft, the visualization element lumen,
and the guide wire lumen. Alternatively, other visualization
methods, e.g., Doppler, fiber optic, and OCT may require a "window"
from the visualization lumen to view the tissue.
[0306] Vacuum is now applied per Step 2, Method 1, evacuating the
dissection plane and locking the sub-intimal tissue onto the
surface of the catheter. Vacuum may be applied through the
visualization element lumen, the optical fiber lumen, or both
lumens.
[0307] Laser energy is delivered to the optical fiber system as
required to ablate the sub-intimal tissue which separates the
dissection plane from the vessel true lumen. If the fiber optic
system that does not incorporate the guide wire is used, the fiber
optic system is removed and a standard guide wire is introduced for
advancement through the pathway in the sub-intimal tissue and into
the true lumen. In the case of the fiber optic system that contains
a guide wire lumen, a guide wire is simply advanced through the
lumen, through the pathway in the sub-intimal tissue, and into the
true lumen.
[0308] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.050 to 0.070 inches; fiber optic system outside diameter is
approximately 0.010 to 0.030 inches; and imaging element outside
diameter is as described in Step 1 above.
[0309] Embodiment 2 (Method 5 Under Step 3) (FIGS. 7 and 8)
[0310] The embodiment of FIG. 7 includes a distal nosecone and a
muti-lumen catheter shaft which house a visualization element per
Methods 1-4 under Step 1, an optical fiber system, and optional
separate vacuum ports. The embodiment of FIG. 8 includes optional
sub-intimal tissue forceps.
[0311] FIG. 47 is a flow diagram for creating a path into a vessel
true lumen using laser energy, under a first alternative
embodiment. Prior to the introduction of the catheter into the
vasculature, the optical fiber system is removed from a
corresponding lumen. The catheter is tracked over a guide wire
within this lumen to the desired sub-intimal location. Once the
catheter is properly advanced in the sub-intimal plane, the guide
wire is removed and the optical fiber system is replaced.
[0312] The visualization element is now activated and the catheter
is properly aligned to the vessel true lumen. Next, vacuum may be
applied per Step 2, Method 2, thereby evacuating the dissection
plane and invaginating the sub-intimal tissue into the catheter
nosecone or distal termination. Note that vacuum may be applied
through the fiber optic lumen, the visualization element lumen, or
through optional vacuum ports like those shown in FIGS. 7 and
8.
[0313] While maintaining alignment to the vessel true lumen, the
visualization element may be retracted proximally into the catheter
shaft, making more room for the sub-intimal tissue to be
invaginated into the nosecone. This may be desired in the case that
the sub-intimal tissue is thick, and requires a deeper purchase in
order to create a pathway into the vessel true lumen. FIG. 8 is a
similar embodiment showing optional forceps or skewers holding the
sub-intimal tissue.
[0314] Next, laser energy is delivered to the optical fiber system
as required to ablate the sub-intimal tissue that separates the
dissection plane from the vessel true lumen. If a fiber optic
system that does not incorporate the guide wire is used, the fiber
optic system is removed and a standard guide wire is introduced for
advancement through the pathway in the sub-intimal tissue and into
the true lumen. In the case of the fiber optic system that contains
a guide wire lumen, a guide wire is simply advanced through the
lumen, through the pathway in the sub-intimal tissue, and into the
true lumen.
[0315] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.050 to 0.060 inches; fiber optic system outside diameter is
approximately 0.010 to 0.030 inches; and imaging element outside
diameter is as described in Step 1 above.
[0316] Embodiment 3 (Method 5 Under Step 3) (FIG. 9)
[0317] This embodiment includes a nosecone or molded catheter
termination attached to the distal end of the catheter, an internal
slidably disposed actuating cannula, and an optical fiber
system.
[0318] The catheter shaft may be any of a number of catheter shafts
known in the art. The nosecone includes a side exit port and a
distal end port coupled via a slot which, and as is described
below, allows the guide wire to translate or move from the side
port into the distal end port when the catheter is retracted
proximally over the guide wire. The cannula is guided out of the
nosecone sideport via an internal exit ramp. The cannula tip of an
embodiment is bluntly terminated, but is not so limited. The angle
of the internal ramp may vary from approximately 30 degrees to 80
degrees, but is not necessarily limited to these angles. The distal
end port of the nosecone allows the catheter to be tracked in a
co-linear fashion over a standard coronary guide wire.
Representative component dimensions of an embodiment are as
follows: side port width is approximately 0.027 inches; slot width
and distal port width are both approximately 0.016 inches; and
cannula outside diameter is approximately 0.025 inches and inside
diameter is approximately 0.016 inches. Note that the internal ramp
is the same width as the side port.
[0319] FIG. 48 is a flow diagram for creating a path into a vessel
true lumen using laser energy, under a second alternative
embodiment. Procedurally, a guide wire is placed in the sub-intimal
space of the target vasculature such that the guide wire distal end
is located distal to the occluded area of the vessel. The cannula
is retracted to a position proximal to the exit ramp so that the
cannula exit port is co-linear with the inner diameter of the
nosecone. This configuration allows the proximal end of the guide
wire to be passed through the nosecone distal end port, the cannula
and the catheter shaft. Thus the catheter may be tracked over the
guide wire to the vascular site.
[0320] Next, the catheter is aligned to the vessel true lumen. This
may be accomplished per under Step 1, Methods 1-4 or Step 1, Method
5. In the scenario where any of Methods 1-4 are used, the guide
wire (and optionally the cannula) is retracted from the catheter,
and the visualization element is advance into the nosecone. The
element is activated at the nosecone side port and the side port is
rotated to face the vessel true lumen. The visualization element is
then removed. When using Method 5, the side port is rotated to face
the vessel true lumen per fluoroscopic visualization. The guide
wire is then removed.
[0321] The cannula and fiber optic system are re-introduced. The
distal tip of the optical fiber system is positioned approximately
2 centimeters proximal from the distal tip of the nosecone. At this
point, the application of vacuum can be used to evacuate fluid from
the sub-intimal plane and lock the sub-intimal tissue onto the
surface of the nosecone.
[0322] Next, the cannula is advanced distally and guided through
the internal ramp until it is brought into secure purchase with the
sub-intimal tissue. The optical fiber system is then advanced until
the tip is coincident with the cannula distal tip such that both
are in contact with the sub-intimal tissue.
[0323] Laser energy is now delivered to the optical fiber system as
required to ablate the sub-intimal tissue that separates the
dissection plane from the vessel true lumen. If the fiber optic
system that does not incorporate the guide wire is used, the fiber
optic system is removed and a standard guide wire is introduced for
advancement through the pathway in the sub-intimal tissue and into
the true lumen. In the case of the fiber optic system that contains
a guide wire lumen, a guide wire is advanced through the lumen,
through the pathway in the sub-intimal tissue, and into the true
lumen. The cannula is subsequently retracted to its original
position, so that its distal end is positioned just proximal to the
nosecone internal ramp.
[0324] The position of the guide wire is maintained in the vessel
true lumen, and the entire catheter system is retracted from the
vasculature. As the catheter is retracted proximally over the guide
wire, the floppy distal end of the guide wire may be able to pass
through the nosecone side port. However as the nosecone reaches the
stiff mid and proximal sections of the guide wire, the guide wire
falls through the slot connecting the side port with the end port.
Therefore, as the catheter nosecone is retracted over the mid- and
proximal sections of the guide wire, it does so with the guide wire
traveling through the nosecone distal port.
[0325] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; cannula element outside diameter is approximately
0.020 to 0.030 inches; and fiber optic system outside diameter is
approximately 0.010 to 0.030 inches.
[0326] Embodiment 4 (Method 5 Under Step 3) (FIG. 11)
[0327] This embodiment includes a catheter having a simple nosecone
or molded distal termination, a single lumen catheter shaft, and a
fiber optic system slidably disposed in the catheter lumen. The
catheter shaft can be any of a number of catheter shafts known in
the art. The nosecone includes an internal ramp connecting the
catheter lumen with a single side exit port. This design has no
distal port to track over a guide wire. The fiber optic system is
as described above.
[0328] FIG. 49 is a flow diagram for creating a path into a vessel
true lumen using laser energy, under a third alternative
embodiment. Procedurally, the optical fiber system is removed from
the catheter and the catheter is tracked over a standard guide wire
placed in the desired sub-intimal space of the target vasculature.
Because the guide wire emerges laterally from the nosecone, the tip
of the catheter will track eccentrically over the guide wire.
[0329] The catheter is aligned to the vessel true lumen in
accordance with Step 1, Methods 1-4 or Step 1, Method 5 above. In
the case of Methods 1-4, the guide wire is retracted from the
catheter, and the visualization element is advanced into the
nosecone. The element is activated at the nosecone side port and
the side port is rotated to face the vessel true lumen. The
visualization element is removed, and the fiber optic system is
re-introduced. When Method 5 is used the side port is rotated to
face the vessel true lumen per fluoroscopic visualization.
[0330] The distal tip of the fiber optic system is now positioned
approximately 2 centimeters proximal from the distal tip of the
nosecone. At this point the application of vacuum as described
above may be used to evacuate fluid from the sub-intimal plane and
lock the sub-intimal tissue onto the surface of the nosecone.
Vacuum is translated to the nosecone via the single shaft
lumen.
[0331] Next, the fiber optic system is advanced distally into the
nosecone. The fiber optic system is brought into contact with the
sub-intimal tissue at the nosecone side port at an angle determined
by the exit ramp of the nosecone. The angle of the internal ramp
may vary from approximately 30 degrees to 80 degrees, but is not
necessarily limited to these angles.
[0332] Next, laser energy is delivered to the optical fiber system
as required to ablate the sub-intimal tissue separating the
dissection plane from the vessel true lumen. If the fiber optic
system does not incorporate the guide wire, the fiber optic system
is removed and a standard guide wire is introduced for advancement
through the pathway in the sub-intimal tissue and into the true
lumen. In the case of the fiber optic system including a guide wire
lumen, a guide wire is simply advanced through the lumen, through
the pathway in the sub-intimal tissue, and into the true lumen.
[0333] The vacuum is now released, the guide wire position is
maintained, and the catheter is retracted from the vasculature,
leaving the distal portion of the guide wire in place in the vessel
true lumen.
[0334] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; and fiber optic system outside diameter is
approximately 0.010 to 0.030 inches.
[0335] Embodiment 5 (Method 5 Under Step 3) (FIG. 12)
[0336] This embodiment includes a catheter having a simple nosecone
or molded distal termination, a single lumen catheter shaft, an
internal slidably disposed tube, and a fiber optic system which is
slidably disposed in the internal tube. The distal end of the push
tube or member is slidably disposed within the catheter shaft and
nosecone. Upon actuation of the push member in a distal direction,
a percentage of the proximal section of the nosecone side port
becomes covered. The percentage of coverage is controlled by a
distal stop within the nosecone that limits the distal translation
of the internal sliding member or tube. When the internal sliding
member is a tube, it becomes the lumen for both the fiber optic
system and guide wire.
[0337] As the internal sliding member advances into the distal
position, it reduces the effective length of the nosecone side port
and forces the fiber optic system or guide wire to exit the side
port at a more acute angle, or an angle that is more normal to the
axis of the catheter, and more normal to the sub-intimal tissue
plane. This angle is governed by the proximal contact point which
is against the internal sliding member, and the distal contact
point which is against the exit ramp of the nosecone. The greater
acute angle is designed to allow the laser energy to ablate a more
direct and efficient pathway across the sub-intimal tissue.
[0338] FIGS. 50A and 50B show a flow diagram for creating a path
into a vessel true lumen using laser energy, under a fourth
alternative embodiment. Procedurally, the sliding tube may remain
in the catheter at all times. In preparation of the catheter and
during delivery of the catheter to the vascular site, the distal
end of the tube is retracted just proximal to the nosecone.
[0339] The optical fiber system is removed from the catheter and
the catheter is tracked over a standard guide wire placed in the
desired sub-intimal space of the target vasculature. Because the
guide wire emerges laterally from the nosecone, the tip of the
catheter will track eccentrically over the guide wire.
[0340] Next, the catheter is aligned to the vessel true lumen. This
is accomplished per Step 1, Methods 1-4 or Step 1, Method 5. In the
case of Methods 1-4, the guide wire is retracted from the catheter,
and the visualization element is advanced into the nosecone. The
element is activated at the nosecone side port and the side port is
rotated to face the vessel true lumen. The visualization element is
removed. In the case of Method 5, the side port is rotated to face
the vessel true lumen per fluoroscopic visualization. The guide
wire is then removed.
[0341] The internal sliding tube is then advanced until the distal
end reaches the internal stop within the nosecone. The fiber optic
system is introduced into the internal sliding tube and advanced to
within 2 centimeters of the distal tip of the nosecone. At this
point the application of vacuum can be used to evacuate fluid from
the sub-intimal plane and lock the sub-intimal tissue onto the
surface of the nosecone. Vacuum may be translated to the nosecone
via the inner sliding tube, or via the annular lumen between the
catheter shaft and the inner sliding tube. The fiber optic system
is subsequently advanced distally into the nosecone, engaging the
internal ramp, until a distal end reaches the exit of the side port
and is in approximate contact with the sub-intimal tissue.
[0342] Laser energy is delivered to the optical fiber system as
required to ablate the sub-intimal tissue separating the dissection
plane from the vessel true lumen. If the fiber optic system without
a guide wire is used, the fiber optic system is removed and a
standard guide wire is introduced for advancement through the
pathway in the sub-intimal tissue and into the true lumen. When the
fiber optic system includes a guide wire lumen, a guide wire is
advanced through the lumen, through the pathway in the sub-intimal
tissue, and into the true lumen. The vacuum is then released, the
guide wire position is maintained, and the catheter is retracted
from the vasculature, leaving the distal portion of the guide wire
in place in the vessel true lumen.
[0343] Typical dimensions of the catheter components are as
follows: outer shaft/nosecone outside diameter is approximately
0.030 to 0.050 inches; internal slide tube outside diameter is
approximately 0.020 to 0.030 inches; and fiber optic system outside
diameter is approximately 0.010 to 0.030 inches.
[0344] Embodiment 6 (Method 5 Under Step 3) (FIG. 13)
[0345] This embodiment includes a single lumen catheter shaft,
terminated in a "J" tip, used with a fiber optic system, and a
standard guide wire. The "J" tip configuration can be torqued into
position within the sub-intimal plane and directed towards the
sub-intimal tissue. This allows the fiber optic system to be
directed at an angle normal to the sub-intimal tissue, to ablate
the minimum tissue necessary to establish a pathway across the
sub-intimal tissue and into the vessel true lumen.
[0346] The "J" termination of the catheter can be fluoroscopically
visible in an embodiment to facilitate the positioning process in
the sub-intimal plane. This type of termination is fabricated or
molded from fluoroscopically visible materials such as platinum
coils or gold coated stainless steel coils laminated with a variety
of polymers, e.g., nylons, HDPE, and Pebax.
[0347] The "J" tip is designed to straighten in order to track over
a guide wire to the vascular site, yet re-form to the "J" shape
when positioned in the vasculature and the guide wire is retracted.
One embodiment incorporates a visualization window just proximal to
the "J" tip that is used in conjunction with an on-board
visualization technique, per Step 1, Methods 1-4. For the use of
IVUS, for example, this window can be fabricated from HDPE.
[0348] FIGS. 51A and 51B are a flow diagram for creating a path
into a vessel true lumen using laser energy, under a fifth
alternative embodiment. Procedurally, a guide wire is positioned in
the sub-intimal space. The fiber optic system is removed from the
catheter. The distal end of the catheter is loaded onto the guide
wire. In this process the "J" tip is straightened as it tracks over
the wire to the sub-intimal site. Once the terminal end of the
catheter has reached the desired location, the guide wire is
retracted, allowing the "J" tip to re-form.
[0349] The catheter is now aligned to the vessel true lumen per
Step 1, Methods 1-4, or Step 1, Method 5. In the case of Methods
1-4, the guide wire is retracted from the catheter, and the
visualization element is advanced to the visualization window. The
visualization element is activated at the window and the "J" tip is
rotated to face the vessel true lumen. The visualization element is
then removed. In the case of Method 5, the side port is rotated to
face the vessel true lumen per fluoroscopic visualization. The
guide wire is then removed.
[0350] The fiber optic system is then loaded into the catheter and
advanced to within 1 centimeter of the distal end of the catheter
tip. Vacuum is applied through the catheter lumen per Step 2,
method 1 to evacuate the sub-intimal plane. The fiber optic system
is then advanced until its distal end is coincident with the distal
end of the catheter "J" tip, and is brought into approximate
contact with the sub-intimal tissue.
[0351] Laser energy is delivered to the optical fiber system as
required to ablate the sub-intimal tissue that separates the
dissection plane from the vessel true lumen. If the fiber optic
system does not include the guide wire, the fiber optic system is
removed and a standard guide wire is introduced to be advanced
through the pathway in the sub-intimal tissue and into the true
lumen. When the fiber optic system includes a guide wire lumen, a
guide wire is advanced through the lumen, through the pathway in
the sub-intimal tissue and into the true lumen.
[0352] The vacuum is then released, the guide wire position is
maintained, and the catheter is retracted from the vasculature,
leaving the distal portion of the guide wire in place in the vessel
true lumen.
[0353] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; and fiber optic system outside diameter is
approximately 0.010 to 0.030 inches.
[0354] Embodiment 7 (Method 5 Under Step 3) (FIGS. 14A and 14B)
[0355] This embodiment includes a catheter having a nosecone with a
side port and end port connected by a slot, an internal push-ramp
that is actuated by an internal push tube or member, and a fiber
optic system slidably disposed in the catheter. This catheter
includes a distal nosecone having a side port and a separate end
port, a single lumen catheter shaft, and an internal push-tube or
member that is attached to an internal hinged ramp which actuates
within the nosecone side port. This catheter system may be used
with any of the visualization techniques of Step 1.
[0356] The push ramp may be constructed of a flexible metal such as
Nitinol or spring steel, or a polymer such as nylon or PEEK, any of
which can be fabricated with or without appropriate detents to
allow for bending, as required. The distal end of the push ramp is
connected or hinged about the internal distal termination of the
catheter shaft, opposite the side port. When the push tube or
member is fully retracted proximally, the push ramp assumes a
linear configuration, lying essentially flat against the inside
wall of the catheter, opposite the nosecone side port.
[0357] When the push tube or member is advanced distally, the push
ramp forms an incline that leads from the proximal end of the ramp,
opposite the nosecone side port, to the distal end of the side
port. This ramp re-directs the fiber optic system or guide wire
within the nosecone side port as either is advanced distally
through the nosecone side port.
[0358] FIG. 52 is a flow diagram for establishing a path into a
vessel true lumen using laser energy, under a sixth alternative
embodiment. Procedurally, a guide wire is positioned in the
sub-intimal space. The push tube or member is retracted proximally,
and the distal end of the catheter is loaded onto the guide wire.
The catheter is tracked over the guide wire to the desired vascular
location.
[0359] The catheter is then aligned to the vessel true lumen per
Step 1, Methods 1-4, or Step 1, Method 5. When Methods 1-4 are
used, the guide wire is retracted from the catheter, and the
visualization element is advanced to the visualization window. The
visualization element is activated at the nosecone side port and
the side port is rotated to face the vessel true lumen. The
visualization element is subsequently removed.
[0360] When Method 5 is used, the side port is rotated to face the
vessel true lumen per fluoroscopic visualization. The guide wire is
then removed.
[0361] The fiber optic system is loaded into the catheter and the
distal end advanced until it is approximately 2 centimeters
proximal to the nosecone or proximal to the push ramp. Vacuum is
then applied through the catheter lumen per Step 2, method 1 to
evacuate the sub-intimal plane. Vacuum may be applied via within
the push tube or via the annular space between the push-tube and
the catheter shaft. The optical fiber system is then advanced
following the ramp to the nosecone cone port until it is brought
into contact with the sub-intimal tissue.
[0362] Next, laser energy is delivered to the optical fiber system
as required to ablate the sub-intimal tissue separating the
dissection plane from the vessel true lumen. If the fiber optic
system does not incorporate the guide wire, the fiber optic system
is removed and a standard guide wire is introduced for advancement
through the pathway in the sub-intimal tissue and into the true
lumen. When the fiber optic system incorporates a guide wire lumen,
a guide wire is simply advanced through the lumen, through the
pathway in the sub-intimal tissue and into the true lumen.
[0363] The push tube or member is now retracted proximally,
collapsing the internal push ramp to a flat configuration, and
allowing the guide wire to fall through the slot and into the
nosecone distal exit port. The vacuum is then released, the guide
wire position is maintained, and the catheter is retracted from the
vasculature. As the catheter is retracted, the guide wire will
gradually translate through the slot to the nosecone distal end
port, allowing the catheter to be retracted over the guide wire in
a co-linear fashion, and leaving the distal portion of the guide
wire in place in the vessel true lumen.
[0364] Typical dimensions of the catheter components are as
follows: outer shafunosecone outside diameter is approximately
0.030 to 0.050 inches; internal push tube outside diameter is
approximately 0.020 to 0.030 inches; and the fiber optic system
outside diameter is approximately 0.010 to 0.030 inches.
[0365] Embodiment 8 (Method 5 Under Step 3) (FIG. 15)
[0366] This embodiment includes a dual lumen catheter shaft
terminating in a single lumen "J" tip, used in conjunction with an
optical fiber system, an optional visualization system, and guide
wires. This dual lumen catheter shaft has the same "J" type single
lumen distal termination as described in Method 3, Embodiment 7,
with the exception that it transitions proximally to a dual lumen
catheter shaft. Fabrication and materials for the "J" tip are as
described in Method 3, Embodiment 7. The dual lumen catheter shaft
may be fabricated using materials and methods known in the art, and
as cited in other embodiments in this description. This embodiment
allows one of the slidably disposed elements included within either
lumen to be advanced individually into the "J" tip single
lumen.
[0367] The procedure for using this dual lumen catheter is now
described with further reference to FIG. 40. The working element
described in this figure is the fiber optic system discussed
below.
[0368] In a first scenario the first lumen of the dual lumen
includes a standard guide wire and the second lumen includes a
fiber optic system. Procedurally, the fiber optic system is loaded
into its lumen and advanced until it is just proximal of the
entrance to the distal single lumen ("J" tip). The catheter is
loaded onto a guide wire that has been advanced into a sub-intimal
plane. The catheter is then advanced over the guide wire until it
reaches the desired vascular location, and the guide wire withdrawn
just proximal to the entrance to the single lumen. Next, the
catheter is aligned to the vessel true lumen. This embodiment makes
use of Step 1, Method 5 to align the catheter.
[0369] The sub-intimal plane is now evacuated per Step 2, Method 2,
and the optical fiber system is advanced into the "J" tip so that
its distal end is approximately coincident with the distal tip of
the catheter, or pointed towards the sub-intimal tissue. The
procedure used dictates whether the tip of the fiber optic system
is or is not in contact with the sub-intimal tissue. Laser energy
is then delivered as required through the fiber optic system to
ablate the sub-intimal tissue and create a pathway into the vessel
true lumen. Once the pathway is established, the distal end of the
fiber optic system is retracted from the single lumen, and into the
dual lumen. The standard guide wire is then advanced into the
distal single lumen, and out of the "J" tip, through the pathway
produced in the sub-intimal tissue, and into the vessel true lumen.
Lastly, the guide wire is held in place while the catheter is
retracted proximally and removed from the vasculature.
[0370] In a second scenario, the first lumen of the dual lumen
initially contains a visualization element, per Step 1, Method 1-4,
and is exchanged for the fiber optic system. The second lumen
contains a standard guide wire. Procedurally, one lumen of the dual
lumen shaft is loaded with the visualization element and advanced
proximal to the entrance to the distal single lumen. The distal end
of the catheter is then loaded onto a standard guide wire that has
been advanced into a sub-intimal plane. The catheter is advanced to
the desired vascular location, and the guide wire is removed from
the catheter and replaced with the fiber optic system.
[0371] The visualization element is then advanced into the distal
single lumen 25 within the area of the window for viewing, and the
"J" tip is aligned with the vessel true lumen. The visualization
element is then withdrawn from the catheter, and a standard guide
wire is advance into this lumen to just proximal of the single
lumen. Next, the sub-intimal plane is evacuated according to Step
2, Method 2. This may be accomplished through the lumen that houses
either the guide wire, the optical fiber system, or both. Next, the
optical fiber system is advanced into the "J" tip so that its
distal end is approximately coincident with the distal tip of the
catheter, or pointed towards the sub-intimal tissue. The tip of the
fiber optic system may or may not be required to be in contact with
the sub-intimal tissue, as directed by the particular procedure in
use.
[0372] Laser energy is then delivered as required through the fiber
optic system to ablate the sub-intimal tissue and create a pathway
into the vessel true lumen. Once the pathway has been established,
the distal end of the fiber optic system is retracted from the
single lumen, and into the dual lumen. The standard guide wire may
then be advanced into the distal single lumen, and out of the "J"
tip, through the pathway produced in the sub-intimal tissue, and
into the vessel true lumen. Finally, the guide wire is held in
place while the catheter is retracted proximally and removed from
the vasculature.
[0373] Typical dimensions of the catheter components are as
follows: single lumen shaft outside diameter is approximately 0.030
to 0.050 inches; the dual lumen shaft outside diameter is
approximately 0.030 to 0.050 inches (each lumen); and the fiber
optic system outside diameter is approximately 0.010 to 0.030
inches.
[0374] Method 6 Under Step 3: Rotational IVUS Element (FIGS. 9,
11-15, and 19)
[0375] This method describes re-entry using a rotational IVUS
element including a specialized distal boring tip.
[0376] Embodiment 1 (Method 6 Under Step 3) (FIG. 9)
[0377] This embodiment includes a nosecone or molded catheter
termination attached to the distal end of the catheter, an internal
slidably disposed actuating cannula, and an IVUS system with a
specialized tip. Dimensions of the catheter components are as
follows: the single lumen shaft outside diameter is approximately
0.055 inches; the cannula element outside diameter is approximately
0.040 inches; and the IVUS system outside diameter is approximately
0.030 inches.
[0378] Procedurally, with further reference to FIG. 34, this
embodiment is similar to that described for Method 3, Embodiment 3,
with the exception that the IVUS system with the specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0379] Embodiment 2 (Method 6 Under Step 3) (FIG. 11)
[0380] This embodiment includes a catheter having a nosecone or
molded distal termination, a single lumen catheter shaft and an
IVUS system with a specialized tip. Dimensions of the catheter
components are as follows: outer shaft/nosecone outside diameter is
approximately 0.045 inches; and the IVUS system outside diameter is
approximately 0.030 inches.
[0381] Procedurally, with further reference to FIG. 36, this
embodiment is similar to that described for Method 3, Embodiment 5,
with the exception that the IVUS system with a specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0382] Embodiment 3 (Method 6 Under Step 3) (FIG. 12)
[0383] This embodiment includes a catheter having a nosecone or
molded distal termination, a single lumen catheter shaft, an
internal slidably disposed tube, the distal end of which translates
within the catheter nosecone, and an IVUS system with a specialized
tip. Dimensions of the catheter components are as follows: outer
shaft/nosecone outside diameter is approximately 0.050 inches; the
internal slide tube outside diameter is approximately 0.040 inches;
and the IVUS system outside diameter is approximately 0.030
inches.
[0384] Procedurally, with further reference to FIG. 37, this
embodiment is similar to that described for Method 3, Embodiment 6,
with the exception that the IVUS system with a specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0385] Embodiment 4 (Method 6 Under Step 3) (FIG. 13)
[0386] The embodiment includes a single lumen catheter shaft,
terminated in a "J" tip, and an IVUS system with a specialized tip.
Dimensions of the catheter components are as follows: the single
lumen shaft outside diameter is approximately 0.040 inches; and the
IVUS system outside diameter is approximately 0.030 inches.
[0387] Procedurally, with further reference to FIG. 38, this
embodiment is similar to that described for Method 3, Embodiment 7,
with the exception that the IVUS system with a specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0388] Embodiment 5 (Method 6 Under Step 3) (FIG. 14)
[0389] This embodiment includes a catheter having a nosecone or
molded distal termination, an internal push-ramp which is actuated
by an internal push tube or member, a single lumen catheter shaft,
and an IVUS system with specialized tip. Dimensions of the catheter
components are as follows: outer shaft/nosecone outside diameter is
approximately 0.050 inches; the internal push tube outside diameter
is approximately 0.040 inches; and the IVUS system outside diameter
is approximately 0.030 inches.
[0390] Procedurally, with further reference to FIG. 39, this
embodiment is similar to that described for Method 3, Embodiment 8,
with the exception that the IVUS system with a specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0391] Embodiment 6 (Method 6 Under Step 3) (FIG. 15)
[0392] FIG. 15 is an embodiment that includes a dual lumen catheter
shaft, terminated in a single lumen "J" tip, and an IVUS system
with specialized tip. Dimensions of the catheter components are as
follows: the single lumen shaft outside diameter is approximately
0.040 inches; the dual lumen shaft outside diameter is
approximately 0.040 inches (per lumen); and the IVUS system outside
diameter is approximately 0.030 inches.
[0393] Procedurally, with further reference to FIG. 40, this
embodiment is similar to that described under Method 3, Embodiment
9, with the exception that the IVUS system with a specialized tip
provides visualization as well as the subsequent re-entry
mechanism.
[0394] In general, alternatives and alternative embodiments
described herein are substantially similar to previously described
embodiments, and common elements and acts or steps are identified
by the same reference numbers. Only significant differences in
construction or operation are described in detail. The elements and
acts of the various embodiments described above can be combined to
provide further embodiments.
[0395] All of the above references and U.S. patents and
applications are incorporated herein by reference. Aspects of the
invention can be modified, if necessary, to employ the systems,
functions and concepts of the various patents and applications
described above to provide yet further embodiments of the
invention.
[0396] Unless the context clearly requires otherwise, throughout
the description and the claims, the words "comprise," "comprising,"
and the like are to be construed in an inclusive sense as opposed
to an exclusive or exhaustive sense; that is to say, in a sense of
"including, but not limited to." Words using the singular or plural
number also include the plural or singular number respectively.
Additionally, the words "herein," "hereunder," and words of similar
import, when used in this application, shall refer to this
application as a whole and not to any particular portions of this
application.
[0397] The above description of illustrated embodiments of the
invention is not intended to be exhaustive or to limit the
invention to the precise form disclosed. While specific embodiments
of, and examples for, the invention are described herein for
illustrative purposes, various equivalent modifications are
possible within the scope of the invention, as those skilled in the
relevant art will recognize. The teachings of the invention
provided herein can be applied to other catheter systems, not only
for the catheter system described above.
[0398] In general, in the following claims, the terms used should
not be construed to limit the invention to the specific embodiments
disclosed in the specification and the claims, but should be
construed to include all medical systems that operate under the
claims. Accordingly, the invention is not limited by the
disclosure, but instead the scope of the invention is to be
determined entirely by the claims.
[0399] While certain aspects of the invention are presented below
in certain claim forms, the inventors contemplate the various
aspects of the invention in any number of claim forms. Accordingly,
the inventors reserve the right to add additional claims after
filing the application to pursue such additional claim forms for
other aspects of the invention.
* * * * *