U.S. patent application number 10/348991 was filed with the patent office on 2004-05-20 for combination thrombolytic infusion catheter and dilator system.
This patent application is currently assigned to AngioDynamics, Inc.. Invention is credited to Schur, Israel.
Application Number | 20040097880 10/348991 |
Document ID | / |
Family ID | 32233145 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040097880 |
Kind Code |
A1 |
Schur, Israel |
May 20, 2004 |
Combination thrombolytic infusion catheter and dilator system
Abstract
The present systems combines a drug delivery catheter and a
dilator apparatus for use in lysing of clots wherein an internal
dilator has a central lumen and an outer catheter is arranged
coaxially about said internal dilator. An annular space for fluid
passage is sealingly formed between an outer wall of the internal
dilator and an inner wall of the outer infusion catheter. Apertures
are located in the outer wall of the outer catheter for
distributing fluid from the annular space. The internal dilator has
a tip element and the outer catheter has an end opening so that
together the end opening is occluded by the tip element which
protrudes beyond the outer catheter when the outer catheter is
arranged coaxially about the internal dilator and additionally the
internal dilator is removable from the outer catheter to enable the
introduction of a larger guide wire for further medical
procedures.
Inventors: |
Schur, Israel; (Englewood,
NJ) |
Correspondence
Address: |
REED SMITH, LLP
ATTN: PATENT RECORDS DEPARTMENT
599 LEXINGTON AVENUE, 29TH FLOOR
NEW YORK
NY
10022-7650
US
|
Assignee: |
AngioDynamics, Inc.
|
Family ID: |
32233145 |
Appl. No.: |
10/348991 |
Filed: |
January 22, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60427603 |
Nov 19, 2002 |
|
|
|
Current U.S.
Class: |
604/164.01 ;
604/164.13; 604/528; 977/875; 977/906 |
Current CPC
Class: |
A61M 25/007 20130101;
A61M 25/0097 20130101; A61M 29/00 20130101 |
Class at
Publication: |
604/164.01 ;
604/528; 604/164.13 |
International
Class: |
A61M 005/178 |
Claims
What is claimed is:
1. A combination drug delivery catheter and dilator apparatus for
use in lysing of clots comprising: an internal dilator with a
central lumen; an outer catheter arranged coaxially about said
internal dilator wherein an annular space for fluid passage is
sealingly formed between an outer wall of the internal dilator and
an inner wall of said outer infusion catheter; apertures located in
an outer wall of said outer catheter for distributing fluid from
said annular space; said internal dilator having a tip element;
said outer catheter having an end opening; wherein said end opening
is occluded by said tip element which protrudes beyond said outer
catheter when said outer catheter is arranged coaxially about said
internal dilator and wherein said the internal dilator is removable
from said outer catheter.
2. The combination drug delivery catheter and dilator apparatus for
use in lysing of clots of claim 1 wherein: said central lumen of
said internal dilator is dimensioned to accept up to a 0.025"
diameter first guide wire and said outer infusion catheter is
dimensioned to internally accept up to a 0.038" diameter second
guide wire after the internal dilator is removed.
3. The combination drug delivery catheter and dilator apparatus for
use in lysing of clots of claim 2 wherein: said first guide wire
has substantially a 0.018" diameter and said second guide wire has
substantially a 0.035" diameter.
4. The combination drug delivery catheter and dilator apparatus for
use in lysing of clots of claim 2 wherein: said internal dilator
has an outer diameter of 3 French; and said outer catheter has an
outer diameter of 5 French.
5. The combination drug delivery catheter and dilator apparatus for
use in lysing of clots of claim 1 wherein: said outer infusion
catheter includes marking bands located near said apertures to
indicate where a region containing said apertures begins and ends
in said outer wall of said outer catheter.
6. The combination drug delivery catheter and dilator apparatus for
use in lysing clots of claim 1 wherein: said apertures are
uniformly positioned in said outer wall of said outer catheter for
uniformly distributing fluid from said annular space.
7. The combination drug delivery catheter and dilator apparatus for
use in lysing clots of claim 1 wherein: said apertures are pressure
actuated recloseable exit slits normally biased in a closed
position for uniformly distributing fluid in response to
pressure.
8. The combination drug delivery catheter and dilator apparatus for
use in lysing clots of claim 1 wherein: said apertures are small
open orifices.
9. A method for an improved thrombolytic lysing technique
comprising: puncturing a graft with a micropuncture needle;
inserting a micropuncture guide wire through the micropuncture
needle into the graft; removing said needle from the graft;
inserting a combined dilator and catheter apparatus over said guide
wire into the graft, infusing a lysing agent into the graft through
said combined dilator and catheter apparatus via an annular space
formed between an internal dilator and a catheter component with
apertures to distribute the lysing agent to a clot; removing said
internal dilator component of said combined dilator and catheter
apparatus; inserting a second larger guide wire into said catheter
component of said combined dilator and catheter apparatus; and
removing said catheter component from the graft while maintaining
access via said second larger guide wire for subsequent medical
procedures.
10. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said internal dilator component is dimensioned to
accept up to 0.025" diameter first guide wire; said catheter
component is dimensioned to internally accept up to a 0.038"
diameter second guide wire after said internal dilator component is
removed.
11. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said first guide wire has substantially a 0.018"
diameter and second larger guide wire has substantially a 0.035"
diameter.
12. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said internal dilator component has an outer
diameter of 3 French; and said catheter component has an outer
diameter of 5 French.
13. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said catheter component includes marking bands
located near said apertures to indicate where a region of said
apertures begins and ends in said catheter.
14. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said apertures are uniformly positioned in said
outer wall of said outer catheter for uniformly distributing fluid
from said annular space.
15. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said apertures are pressure actuated recloseable
exit slits normally biased in a closed position for uniformly
distributing fluid in response to pressure.
16. The method for an improved thrombolytic lysing technique of
claim 9 wherein: said apertures are small open orifices.
17. A method for enhancing declotting clinic capabilities to
minimize patient time and costs incurred in using specialized
procedure rooms associated with thrombolytic declotting procedures
comprising: performing on a patient located outside of the
specialized procedure rooms the steps of: puncturing a graft with a
micropuncture needle, inserting a micropuncture guide wire into the
graft through the micropuncture needle; removing the micropuncture
needle from the graft; inserting a combined dilator and catheter
apparatus over said guide wire into the graft; infusing a lysing
agent into the graft through said combined dilator and catheter
apparatus to distribute lysing agent to a clot; removing an
internal dilator component of said combined dilator and catheter
apparatus and removing said micropuncture guide wire; and inserting
a second larger guide wire into a remaining catheter component of
the dilator and catheter apparatus to maintain graft access in
preparation for further medical procedures.
18. The method of claim 17 wherein said micropuncture guide wire
has substantially a 0.018" diameter and said second larger guide
wire has substantially a 0.035" diameter.
19. The method of claim 17 wherein the further medical procedure is
declotting of veins or arteries.
20. The method of claim 17 wherein the further medical procedure is
angioplasty.
21. A combination drug delivery dilator and catheter medical kit
system enabling performance of a further medical procedure
following a thrombolytic procedure comprising: an internal dilator
with a central lumen adapted to accept a first guide wire, and with
a dilator tip adapted for track dilation and occlusion; an outer
infusion catheter arranged coaxially and moveably about said
internal dilator wherein an annular space for fluid passage is
sealingly formed between an outer wall of the internal dilator and
an inner wall of said outer infusion catheter, for introducing said
fluid into said annular space; apertures located in an outer wall
of said outer infusion catheter for distributing the fluid from
said annular space; said internal dilator being removable from said
outer infusion catheter to enable subsequent passage of a second
larger guide wire through said outer infusion catheter.
Description
[0001] This application claims priority under 35 U.S.C. .sctn.119
(e) to U.S. provisional application, 60/427,603, filed Nov. 19,
2002, the disclosure of which is hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a medical device apparatus
and method for infusion therapy. More particularly, the present
invention relates to a coaxial infusion catheter device and method
for use in dissolving blood clots.
BACKGROUND OF THE INVENTION
[0003] Thrombosis, or blood clot formation, is the most common
cause of hemodialysis access graft failure. Graft thrombosis
usually results from venous flow obstruction, or stenosis. The
location of the stenosis is most commonly found at the graft-vein
anastomosis. A narrowing at this area causes a slow down or
obstruction of blood flow resulting in the formation of the
thrombus within the graft. Venous stenosis is present in over
eighty-five percent of clotted grafts. The underlying venous
anastamotic stenosis must be corrected in order to avoid recurrence
of the thrombus. The venous stenosis is usually treated with
balloon angioplasty after the graft has been cleared of the
thrombus.
[0004] Treatment options for thrombosed grafts include surgical
thrombectomy, graft replacement, or percutaneous endovascular
thrombolysis. Percutaneous thrombolysis is the least invasive
treatment option and has rapidly become the preferred method of
treatment at most institutions. It can be accomplished using
mechanical thrombectomy devices that macerate the clot or by using
a thrombolytic agent to dissolve the clot. Mechanical thrombectomy
devices are expensive and often require capital investment.
Thrombolytic agents provide a less expensive treatment option.
[0005] Tissue plasminogen activators, also known as TPA, are one of
the most commonly used thrombolytic agents for clearing dialysis
grafts. The drug is introduced into the clotted graft via an
infusion catheter or a needle. TPA has a high affinity and
specificity for fibrin, a major component of blood clots. It acts
upon the clot by binding to the surface and dissolving it by an
enzymatic reaction. Time until clot dissolution is dependent on the
length and size of the clot, the amount of drug delivered, and
method used for drug delivery.
[0006] With the "lyse and wait" technique of thrombolysis, TPA or
other thrombolytic agent such as urokinase or retaplase is
delivered to the graft by a small gauge needle or an infusion
catheter. Manual compression is applied to the graft anastomoses
during drug administration to ensure targeted drug delivery is
restricted to the graft. The procedure is performed without the aid
of fluoroscopic guidance. The therapeutic action of the lytic agent
typically takes at least one hour depending on the effective
distribution of the lytic agent. After clot dissolution, the
patient typically is brought into the angiographic suite for
fluoroscopic imaging of the graft to identify and visualize
residual venous stenosis. Angioplasty of the stenosed segment can
then be performed.
SUMMARY OF THE INVENTION
[0007] The "lyse and wait" technique of graft clearance has several
advantages over other treatment options. With "lyse and wait", the
overall procedure time is shortened, the AngioSuite time is
minimized, the costs associated with expensive mechanical
thrombolysis devices is eliminated and the success rate for
clearance is relatively high. Despite these advantages, the
traditional "lyse and wait" technique has several potential
problems which prevent these advantages from being widely accepted
in practice.
[0008] When a needle, catheter, or other end hole device is used,
non-uniform distribution of the lytic agent across the clot occurs.
Therapeutic drug delivery using an end hole device results in
concentrated lytic action at the location in the graft where the
tip is positioned and insufficient lytic action at locations
distant from the tip. This non-uniform drug delivery can result in
incomplete thrombus resolution, reduced flow rates, and potential
clot migration downstream. In addition, the non-uniform drug
delivery results in a longer clot dissolution time period,
potentially several hours in duration. Accordingly, there exists a
need to provide a uniform distribution of the lytic agent across
the entire clot without the use of fluoroscopy.
[0009] Furthermore, when an end hole infusion catheter is used as
the drug delivery device, the drug must be slowly infused to
prevent concentrated jet action through the end hole. Not only does
this jet action concentrate the lytic agent in a single location,
but it also may cause clot fragmentation and subsequent migration.
To avoid high pressure localized delivery and the potential
complications, the drug is delivered using a slow infusion method
which typically takes three to five minutes with adequate clot
dissolution taking up to several hours. Accordingly, there exists a
need for an infusion catheter assembly which can a deliver lytic
agent quickly and uniformly across the clot without causing a
potentially harmful jet action.
[0010] To retain the lysing agent within the graft when an end hole
catheter or needle is used, the ends of the graft are radially
compressed during the injection period. The infusion of the lytic
agent through an end hole catheter or angiocath needle is
administered slowly over a 3-5 minute period. Compression is
required during this infusion time period to ensure that the
concentrated drug bolus remains within the graft. Without
compression, distribution of the drug to non-targeted areas outside
the graft is possible. Providing a infusion catheter device which
does not require manual compression during drug injection would
allow physicians to quickly and efficiently administer the drug
without the assistance of additional medical personnel.
[0011] To overcome the non-uniform distribution of the lytic agent,
a standard infusion catheter is sometimes used. The catheter is
designed with either side holes or slits located along a specified
segment of the catheter shaft. The drug exits these side holes
equally along the entire length of the clot. Injections using a
side hole catheter can be accomplished in one bolus action in three
to five seconds rather than over a five-minute period as with an
end-hole catheter. Typical drug dwell time within the graft is much
less than with an end hole catheter due to uniform and more
complete distribution of lytic agent.
[0012] Although it provides uniform drug delivery, the infusion
catheter technique requires the use of multiple components. In
order to access the graft, a needle, guidewire and micropuncture
sheath introducer with dilator are required. After the
sheath/dilator is removed, an infusion catheter is inserted over
the guidewire and into the graft. These additional components not
only add to the cost of the device but also add time to the
procedure.
[0013] In summary, there exists a need for a thrombolytic device
that can be percutaneously placed in an outpatient procedural room
setting without the use of fluoroscopic guidance. The insertion
device should create a minimal puncture. In a preferred embodiment,
the device should be able to go over a 0.018" guidewire and provide
uniform delivery of the thrombolytic agent without requiring manual
compression of graft ends. The procedure should minimize catheter
exchanges during a declotting procedure by using a micropuncture
catheter as both an access device and an infusion device. The
device should allow for the exchange to a 0.035" guidewire and
associated procedural components so as to eliminate the need for
multiple dilation steps. In addition, the product should be simple
to use and inexpensive to manufacture which further improves the
business method aspects of the present invention.
[0014] Disclosed is an improved infusion catheter device and method
for de-clotting procedures. Specifically, a medical device kit is
disclosed comprised of components to access the graft, rapidly
deliver the therapeutic agent in a uniform distribution pattern
across the entire clot, or in a concentrated pattern, and to
maintain graft access in preparation for stenosis treatment using
angioplasty. By combining components needed for micro-access with a
novel infusion catheter/dilator assembly, the procedure eliminates
the need for exchange of catheters to accommodate the 0.035" wire
or other second guide wire which is larger than the first guide
wire. By using a micropuncture catheter as both an access device
and an infusion device, the present invention eliminates catheter
exchanges during the graft-declotting portion of the procedure.
[0015] In a preferred embodiment, the system and apparatus is a kit
comprised of a micropuncture needle and compatible guide wire and
an infusion catheter/dilator assembly.
[0016] Initial access to the graft may be established using
standard Seldinger technique. A small-gauge standard micropuncture
needle, typically 21-gauge, is inserted into the graft. An 0.018"
guidewire is then inserted into the graft through the needle lumen
and the needle is removed. The infusion catheter/dilator assembly
is inserted into the graft over the guidewire. The size and
configuration of the catheter/dilator assembly are designed for
easy insertion over an 0.018" guidewire without the need for a
micro-access sheath/dilator component to pre-dilate the tract.
Typically in the present invention the outer diameter of the
catheter/dilator assembly is 5 French approximately 0.067 inches
and the outer diameter of the internal dilator is 3 French
approximately 0.040 inches.
[0017] Once the device is positioned within the graft, the lytic
agent is infused into the outer catheter using a standard syringe.
The drug is preferably delivered through a side port in the
catheter in a single bolus. Under low, steady pressure, the fluid
advances into the annular space formed between the dilator and
catheter. Occlusion of the catheter end hole by the dilator causes
the drug to exit from the slits in the wall of the catheter into
the clot mass. The drug will not exit from the end hole of the
catheter because it is completely occluded by the dilator.
[0018] Only a small amount of drug is required because of the
efficient delivery distribution. In addition, there is no need to
reposition the catheter to ensure drug application to all segments
of the clot. Because the side slits are used for drug delivery
rather than the catheter end hole, drug delivery is rapid and
uniform with no end hole "jet action". Accordingly, there is no
need to apply manual compression to the graft anastomoses during
drug delivery to ensure uniform and localized drug
distribution.
[0019] The present invention includes marking bands that show the
position and length of the infusion section or region with the
slits or small openings for distributing the lysing agent. These
slits allow drug injection at a much faster rate. Typically, 5-10
cc of lytic agent can be delivered to the clot within 3-5 seconds.
Because of the rapid and efficient distribution of the lytic agent,
time to clot dissolution is decreased. Typically, only 20 to 45
minutes is necessary to declot the graft. Therefore, the efficiency
and capacity of the whole clinic is improved because more patients
can be treated in a shorter period of time within the outpatient
area. Procedural time requiring use of the more expensive angio
and/or fluoroscopy suites is limited to the angioplasty
procedure.
[0020] Once the drug is delivered, the dilator is removed and the
catheter is capped off using a standard closed connector type
component. When ready for the angioplasty procedure, an 0.035"
guidewire or other suitable device can be inserted into the graft
through the lumen of the infusion catheter component. An additional
catheter exchange is not required because the infusion catheter
component will accommodate the larger guidewire size. The infusion
catheter component can then be removed leaving the 0.035" guidewire
in place to maintain site access. Angioplasty can then be performed
using the already placed guidewire. Re-establishing access to the
graft and use of a separate dilator is not required.
RELATED PRIOR ART
[0021] Micro access sets have been available for years and are
considered public domain material. Thrombolysis as a therapy for
vascular graft clearance has been taught since the late-1970s.
Several infusion catheter designs have been patented. These designs
focus on the uniform distribution of the therapeutic agent across
the entire clot surface.
[0022] U.S. Pat. No. 5,425,723, Wang covers an infusion catheter
with an infusion segment at its distal end. The device includes an
inner and outer tubular body. The inner tubular body is spaced
apart from the outer tube to provide an annular passageway for the
delivery of fluid. The design provides for a uniform average flow
rate of therapeutic fluid along the length of the infusion segment
by the positioning of fluid exit holes on both the inner and outer
tubes.
[0023] Fluid is introduced to the central lumen of the inner
catheter. The therapeutic fluid flows distally and also out the
inner catheter exit holes into the annular space between the inner
and outer catheter. From the annular space, the fluid flows through
the outer catheter exit holes and into the vessel. This indirect
flow path counterbalances the decreasing pressure gradient at the
distal segment of the catheter, providing a more even drug
delivery.
[0024] Although an annular space exists for fluid flow between the
inner and outer catheter components, the device disclosed by Wang
differs significantly from the device of the present invention. The
Wang catheter design requires the introduction of fluid into the
inner catheter lumen and the fluid only indirectly flows into the
annular space. In addition, the inner catheter does not perform a
dilation function nor does it occlude the end hole of the outer
catheter. The inner catheter cannot be removed to allow the
introduction of a larger guidewire.
[0025] U.S. Pat. 5,800,408 Strauss, et al., covers an improvement
on the Wang '723 concept of an infusion catheter. Like Wang's
patent, the device includes an inner and outer tubular body with
annular passageway between the two for fluid delivery. Instead of
having a series of equally spaced exit holes on the inner catheter,
Strauss et al., provides a distal and proximal set of exit holes on
the inner catheter. This configuration forces fluid to flow
distally in the annular space from the proximal holes and
proximally from the distal holes. This flow configuration provides
enhanced uniform distribution patterns. Strauss et al., also
discloses a proximal hub mechanism for adjusting the flow path from
one lumen to another.
[0026] Again, the concept outlined in the patent differs
significantly from the concept of the present invention. The flow
path adjustment mechanism can be used to divert flow completely to
the annular passageway between the two catheter tubes. Strauss et
al., teaches this flow pattern as a way of concentrating fluid
delivery proximally rather than for achieving equal flow
distribution. Like the Wang disclosure, the inner catheter does not
perform a dilation function nor does it occlude the end hole of the
outer catheter. The inner catheter cannot be removed to allow the
introduction of a larger guidewire.
[0027] U.S. Pat. No. 5,250,034 Appling, et al., covers a single
lumen infusion catheter for introducing therapeutic agents into the
body. The distal segment of the catheter includes pressure
responsive valves that provide for uniform fluid distribution.
Appling et al., teaches the use of this catheter design for
high-pressure injection at relatively high velocities. An occluding
ball wire occludes the catheter end hole.
[0028] While the patent does include the concept of pressure
responsive slits for uniform drug delivery, it uses an occluding
ball and does not disclose the use of dilator insertion technique.
In addition, Appling does not teach the combination of a
micro-puncture access set with an infusion catheter specifically
for use in outpatient pre-angioplasty graft de-clotting
procedures.
[0029] U.S. Pat. No. 5,021,044, Sharkawy covers a multi-lumen
catheter for delivery of thrombolytic agents to a blood vessel. The
catheter has a first inner lumen for receiving a guidewire, and at
least one additional lumen for the delivery of drugs. The coaxial
catheter design includes an annular space for the fluid path
between the inner and outer catheter tubes. A side-arm port is used
to direct drug delivery into the catheter through the annular space
between the two catheter tubes. Flow passageways are provided on
the distal portion of the outer catheter. These passageways
increase in cross-sectional area in a distal direction. The
difference in cross-sectional areas provides for uniform fluid
delivery.
[0030] Although Sharkawy teaches a coaxial catheter to direct the
drug flow uniformly through side holes in the catheter, the claims
focus on maintaining a desired flow pattern to the target site
through the use of non-uniform side holes. He does not teach using
the inner catheter for dilation nor does he disclose use of the
inner catheter to provide an end hole occluding function. The inner
catheter cannot be removed to accommodate introduction of a larger
guidewire. There is no discussion of micro access or of specific
teachings for dialysis graft de-clotting.
[0031] U.S. Pat. No. 6,245,045 Stratienko covers a vascular
interventional device for introduction over a guidewire with an end
hole and side holes for fluid infusion. The catheter hub is
designed to accept another device through its lumen (a dilator) and
to accept fluid through a side port. The device includes a dilator
for insertion into the device which is dimensioned such that it
will fit over a guidewire and within the lumen of the catheter.
[0032] There are several key differences between this patent and
the present invention. The dilator and sheath components of the
'045 invention fit snugly together. This fit does not provide
sufficient annular space between the components for infusion of
fluid. The coaxial lumen is simply too small for infusions. Before
a fluid can be introduced, the dilator must be withdrawn from the
sheath and another interventional device inserted. In addition,
Stratienko's device includes a standard hemostasis sheath.
Hemostasis sheaths are intended to accommodate large interventional
devices. The micropuncture set design of the present invention on
the other hand is intended to minimize the access puncture size.
The micro access components, unlike the hemostasis sheath, allow
access with minimal trauma and provide a gradual transition path
for larger devices.
BRIEF DESCRIPTION OF THE FIGURES
[0033] FIG. 1 is a cross-sectional view of the preferred embodiment
of the present infusion catheter/dilator system and apparatus.
[0034] FIG. 2 is a plan view of the inner dilator.
[0035] FIG. 3 is a plan view of the outer catheter.
[0036] FIG. 4 is a plan view of the preferred embodiment of the
infusion catheter/dilator assembly.
[0037] FIG. 5A is a schematic view of the infusion catheter/dilator
assembly within a dialysis graft prior to lysing treatment.
[0038] FIG. 5B is a schematic view of the infusion catheter/dilator
assembly within a dialysis graft during the lysing procedure.
[0039] FIG. 5C is a schematic view of the infusion catheter within
the dialysis graft after undergoing lysing showing the clot
cleared.
DESCRIPTION OF REFERENCE NUMERALS
[0040] Turning now descriptively to the drawings, similar reference
characters denote similar elements throughout the views. The
following numbering is used throughout the various drawing
figures:
[0041] 1 Coaxial infusion catheter system
[0042] 2 Inner dilator
[0043] 3 Outer catheter
[0044] 4 Dilator side port hub
[0045] 5 Annular fluid passage way
[0046] 6 Outer catheter side hole slits
[0047] 7 Distal infusion zone marker
[0048] 8 Proximal infusion zone marker
[0049] 9 Dilator shaft
[0050] 10 Dilator through lumen
[0051] 11 Dilator hub
[0052] 12 Dilator distal tip
[0053] 13 Catheter distal tip
[0054] 14 Dilator through lumen port
[0055] 15 Dilator end hole
[0056] 16 Rotating collar of dilator
[0057] 17 Outer catheter hub
[0058] 18 Outer catheter through lumen
[0059] 19 Infusion zone
[0060] 20 Positioning marker
[0061] 21 Outer catheter end hole
[0062] 22 Graft
[0063] 23 0.018" guidewire
[0064] 24 Clot mass
[0065] 25 Syringe
[0066] 26 Venous stenosis
[0067] 27 0.035" guidewire
[0068] 28 Puncture site
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0069] The present invention can be understood by reference to the
FIGS. 1 through 5A-5C. The preferred embodiment of the present
invention is based on a coaxial infusion catheter system 1 depicted
in FIG. 1. The system is comprised of an internal dilator 2
component shown in FIG. 2 and an outer catheter 3 component shown
in FIG. 3. Fluid is infused through a sideport hub 4 into the
annular space or annular fluid passageway 5 between the outer wall
of dilator 2 and the inner wall of outer catheter 3. For example, a
syringe 25 containing the lytic agent can be connected to the
sideport hub 4. When injected through the side port 4, the fluid
advances through the annular fluid passageway 5 exiting through the
side port slits 6 of the outer catheter 3 into the graft.
[0070] The device components are dimensioned such that the infusion
zone 19 (defined as the distance between the distal infusion zone
marker 7 and the proximal infusion zone marker 8 in FIG. 3) is
maximized and the device length outside the patient is minimized.
Specifically, the infusion zone 19 length must correspond to the
patient's overall graft or clot mass 24 length (see FIGS. 5A-5C) in
order to ensure uniform drug delivery throughout the graft 22. The
portion of the device external to the patient is kept as short as
possible to avoid complications arising from patient movement
during lyse time which is performed in an outpatient waiting room
as opposed to a specialized procedure room such as an AngioSuite or
fluoroscopy suite. In addition, the sterile field within an
outpatient waiting room setting is restricted. The guidewire,
catheter hub and other components external to the patient are
intentionally dimensioned to work within restricted or small
sterile fields. After the lytic agent is injected, the dilator and
guidewire are typically removed and the outer catheter capped off
to minimize external component exposure and to maintain the sterile
field.
[0071] In the preferred embodiment, the removable inner dilator 2
of FIG. 2 is comprised of a tubular dilator shaft 9 made of nylon
or other similar material and a plastic dilator hub 11. Preferably,
the dilator 2 has a 3 French outer diameter with a central lumen 10
that is continuous from the dilator hub 11 to the distal tip end 12
and which accepts a standard 0.018" micro-access guidewire. The
dilator tip 12 is tapered to facilitate insertion and dilation of
the access track. When assembled with the outer catheter 3 as shown
in FIG. 4 the dilator tip 12 extends beyond the catheter distal tip
13 by 1 to 2 cm. The combined dilator tip 12/catheter tip 13
provides an a traumatic profile for gradual access track
dilation.
[0072] The hub end 11 of the dilator 2 preferably includes two
separate infusion ports, a straight through lumen port 14 and a
side port 4. Lumen 10 is continuous from the hub port 14 to the
distal end of the dilator tip 12 thus providing a direct fluid path
from the hub 14 to the end hole 15. Side port 4 is used to inject
fluid into the annular space 5 created when the catheter 3 and
dilator 2 are assembled together as shown in FIG. 1. Fluid entering
through the side port 4 flows into the annular space 5 between the
outer wall of the dilator shaft 9 and the inner wall of the outer
catheter 3. The hub end 11 of the dilator 2 preferably includes a
rotating male luer thread collar 16. When the dilator 2 and
catheter 3 are assembled, collar 16 engages the outer catheter hub
17, providing a sealed connection between the two components. The
rotating design of the collar 16 allows disengagement of dilator 2
from the outer catheter 3 without causing movement and possible
misalignment of the outer catheter 3 within the graft.
[0073] Referring now to FIG. 3, the outer infusion catheter 3 has a
nylon (or other suitable material) tubular body. In the preferred
embodiment, the catheter 3 is of 5 French diameter with a central
lumen 18 that is continuous from the proximal to the distal end of
the catheter 3. The tubular shaft portion of the catheter 3
includes an infusion zone 19 with a plurality of slits 6, which
serve as pressure responsive valves, as described in U.S. Pat. Nos.
5,205,034 and 5,267,979. The pressure responsive slits 6 permit
fluid to exit from the catheter lumen 18 in response to a pressure
level created by introduction of fluid into the lumen by a syringe.
Alternatively, the outer infusion catheter 3 may include a
plurality of side holes rather than pressure responsive slits.
[0074] As shown in FIG. 3, the infusion zone 19 of the outer
catheter 3 is defined as the shaft portion between the distal
infusion zone marker 7 and the proximal infusion zone marker 8.
Lytic agent injected through the dilator side port 4 into the
annular space 5 will exit from the slits 6 on the shaft portion
between the two markers 7 and 8 as shown in FIG. 4. Typically,
marker 8 is positioned 1 cm proximal to the proximal most pressure
responsive slit 6 and marker 7 is positioned on the catheter 3
approximately 1 cm distal to the distal most pressure responsive
slit 6. The outer catheter 3 may also have an additional marker,
the positioning marker 20. The purpose of positioning marker 20 is
to assist the physician in accurately positioning the infusion zone
19 within the graft. Typically, indicator marker 20 is positioned
on the catheter 3 shaft about 1 cm proximal to infusion zone marker
8. Positioning marker 20 provides a visual indication of location
and depth of the infusion zone 19 segment of the catheter 3, thus
ensuring that lytic agent is not infused into a non-target area
outside of the graft.
[0075] As depicted in FIG. 4, the dilator 2 fits within outer
catheter 3 and is sealably connected to the catheter hub 17 by
engaging the rotating collar 16. In the preferred embodiment, the
outer catheter 3 is a 5 French catheter with an outer diameter of
approximately 0.067" and an inner diameter of approximately 0.048".
The annular passageway for fluid flow is created between the 3
French dilator and the 5F outer catheter when assembled together.
The dimensions of the annular space is sufficient to allow the
desired fluid flow into the clot.
[0076] The dilator 2 also performs the function of occluding the
outer catheter 3 end hole 21 when fully inserted into the catheter
lumen 18. The dilator 2 and catheter 3 components are dimensioned
such that the dilator 2 fits snugly within and occludes the
catheter end hole 21. In the preferred embodiment, the outer
diameter of the dilator 2 and the end hole 21 of the outer catheter
3 are both approximately 0.040" thus providing occlusion of the
catheter end hole 21. The lumen 18 of the outer catheter 3 is
approximately 0.048" in diameter transitioning down to a 0.040"
diameter at the outer catheter tip area 13. A separate occluding
element such as an occluding ball or wire is not required with the
current invention.
[0077] The dilator distal tip 12 extends approximately 1-2cm beyond
the distal tip 13 of the outer catheter 3. Tip 12 is tapered to
provide a smooth, gradual transition between the 0.018" guidewire
diameter and the dilator outer diameter. Similarly, the outer
catheter 3 distal tip 13 is also tapered to provide a smooth
transition between the dilator 2 and the outer diameter of catheter
3. This transition zone facilitates insertion and dilation of the
access track without requiring the use of a separate micropuncture
sheath dilator.
[0078] The catheter/dilator assembly 1 depicted in FIG. 1 is novel
in several aspects. The annular space 5 between the catheter 3 and
dilator 2 is large enough to provide a fluid passageway. The
pressure responsive valves 6 ensure uniform distribution of the
drug. The dilator 2 provides multiple functions including track
dilation, which eliminates the need for a separate
introducer/sheath dilator as required in the art. The dilator 2
also acts as the occluding mechanism for the catheter end hole 21,
eliminating the need for an occluding ball guidewire or other
standard end hole occlusion mechanism as required in the art. The
dilator 2 accepts up to an 0.025" guidewire, but can be removed to
allow the insertion of up to an 0.038" guide wire through the
catheter lumen 18, whereby eliminating the need to re-establish
access for angioplasty for example. Therefore, the present
invention eliminates steps and structures required in the art,
allows the patient to be in the outpatient room or clinic receiving
lyse and wait therapy to dissolve the clot, which minimizes the
time the patient will have to spend in the much more expensive
angio suite or fluoroscopy room. Accordingly, the entire clinic is
made more efficient from a capacity and business standpoint.
[0079] Method of Use
[0080] The method of use of the current invention is described in
reference to FIGS. 5A through 5C. While in the outpatient area, a
micropuncture needle (not shown) is used to puncture the skin
adjacent to the graft at puncture site 28. The needle is inserted
into the graft 22 pointing in the direction of the venous
anastomosis. An 0.018" guidewire 23 is inserted through the needle
and into the graft 22. After the needle is removed, the
dilator/catheter assembly 1 of the current invention is introduced
into the graft 22 by advancing the assembly 1 over the guidewire
23. The catheter/dilator assembly 1 is advanced as a unit into the
graft 22 until positioned within the clot mass 24 as shown in FIG.
5A. The positioning marker 20 is used as a visual indicator of the
overall position of the infusion zone 19, thus providing the
physician with confirmation that the infusion zone 19 is completely
within the occluded graft 22 as shown in FIG. 5B.
[0081] While still in the outpatient clinic area, a syringe 25
containing the lytic agent is connected to the side port hub 4 of
the catheter/dilator assembly 1. The lytic agent is injected
through the annular passageway 5 between the inner dilator 2 and
outer catheter 3 (FIG. 1) and exits from the plurality of slits 6
into the clot mass 24 as depicted in FIG. 5B. Typically, between 5
and 10 cc of lytic agent is injected uniformly into the clot mass
24 over a period of 3-5 seconds. Manual compression of the arterial
and venous ends of the graft 22 is not required due to the targeted
distribution of the lytic agent which is restricted to the clotted
25 area. The 0.018" guidewire 23 may remain in place within the
lumen 10 of the dilator 2 or may be removed, based on the
physician's preference. The patient remains in the outpatient
clinic area while the lytic agent dissolves the clot mass 24. Due
to the uniform distribution of the drug across the entire clot mass
24, lysing time may be a short as 20 minutes.
[0082] When lysis is complete, the patient is brought into the
fluoroscopic or angiographic suite for an angiogram of the graft
22. Injection of contrast media can be administered directly
through the dilator/infusion catheter system 1. Typically, dilator
2 is removed and contrast media is injected directly into hub 17 of
outer catheter 3 exiting from the end hole 21. Alternatively,
contrast media is injected through the straight through port 14
into the lumen of the inner dilator and exits out of the dilator
end hole 15. Contrast media can also be injected through the side
port 4 causing distribution of the fluid through the side holes or
slits 6. The angiogram will identify any residual venous stenosis
26.
[0083] In preparation for dilation of the venous lesion 26, the 3F
dilator 2 is detached and removed from the outer catheter 3. A
0.035" guidewire 27 is then inserted through the lumen 18 of the
outer catheter 3 and advanced through the catheter end hole 21 into
the venous stenosis 26, as depicted in FIG. 5C. Once guidewire 27
is positioned across the venous stenosis 26, the outer catheter 3
is removed from the cleared graft 22. A high-pressure angioplasty
balloon is typically used to dilate the stenosed venous segment 26.
The angioplasty balloon can be advanced directly over the
already-in-place 0.035" guidewire 27 or can be introduced using a
standard sheath assembly.
[0084] Other Embodiments
[0085] While certain novel features of this invention have been
shown and described above, the present invention may be embodied in
other specific forms without departing from the spirit or essential
characteristics of the invention such as different catheter sizes,
materials, and configurations and different guide wire sizes. The
described embodiments are to be considered in all respects only as
illustrative and not as restrictive. Clearly, the invention also
envisions the use of different sized catheters and wires. For
example, in the future where still conceptual devices such as
nano-technology sized microsurgical robots, and fiber optics for
lasers, may be guided over wires and into grafts or other ports to
the body. Various omissions, modifications, substitutions and
changes in the forms and details of the device illustrated and in
its operation can be made by those skilled in the art without
departing in any way from the spirit of the present invention.
* * * * *