U.S. patent application number 10/748036 was filed with the patent office on 2004-08-05 for devices, systems and methods for creating sutureless on-demand vascular anastomoses and hollow organ communication channels.
Invention is credited to Kim, Ducksoo, Levine, Andy H., Nissenbaum, Michael.
Application Number | 20040153112 10/748036 |
Document ID | / |
Family ID | 24866713 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040153112 |
Kind Code |
A1 |
Nissenbaum, Michael ; et
al. |
August 5, 2004 |
Devices, systems and methods for creating sutureless on-demand
vascular anastomoses and hollow organ communication channels
Abstract
The present invention provides devices, systems, assemblies, and
methods intended for the introduction and sutureless juncture of a
prepared communication channel to the interior spatial volume of a
blood vessel or a hollow organ within a living subject. The
introducer assembly and system is functional and suitable as a
complete substitute and replacement for conventionally used
apparatus and methods for performing vascular bypass graft surgery
in order to overcome an obstruction in a major artery or vein
in-vivo. The introducer assembly and system is also most
appropriate for use in providing penetration and juncture of a
tubular conduit for use as an access duct in order to drain
materials from or introduce fluids into the interior spatial volume
of a hollow organ in-vivo.
Inventors: |
Nissenbaum, Michael;
(Frenchville, ME) ; Kim, Ducksoo; (Dover, MA)
; Levine, Andy H.; (Newton, MA) |
Correspondence
Address: |
David Prashker
DAVID PRASHKER, P.C.
P.O. Box 5387
Magnolia
MA
01930
US
|
Family ID: |
24866713 |
Appl. No.: |
10/748036 |
Filed: |
December 29, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10748036 |
Dec 29, 2003 |
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09713589 |
Nov 15, 2000 |
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6669708 |
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60169874 |
Dec 9, 1999 |
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Current U.S.
Class: |
606/185 ;
606/213 |
Current CPC
Class: |
A61B 17/11 20130101;
A61B 2017/1107 20130101; A61B 2017/00252 20130101 |
Class at
Publication: |
606/185 ;
606/213 |
International
Class: |
A61B 017/08 |
Claims
What we claim is:
1. A catheterless, piercing introducer assembly suitable for the
introduction and sutureless juncture of a prepared communication
channel to the interior space of an anatomic body part within a
living subject, said introducer comprising: a perforator instrument
comprised of (i) at least one elongated supporting shaft of
predetermined overall dimensions and axial configuration, (ii) a
handle attached at one end to said supporting shaft; and (iii) a
perforating headpiece integrally joined to the other end of said
supporting shaft, said perforating headpiece comprising a
perforating tip, a penetrating body, and a base aspect; and
communication channel controlling means disposed adjacent to said
perforating headpiece on said supporting shaft of said perforator
instrument.
2. A catheterless, piercing introducer assembly suitable for the
introduction and sutureless juncture of a prepared communication
channel to the interior space of an anatomic body part within a
living subject, said introducer assembly comprising: a perforator
instrument comprised of (i) at least one elongated supporting shaft
of predetermined overall dimensions and axial configuration (ii) a
handle attached at one end to said supporting shaft; and (iii) a
perforating headpiece integrally joined to the other end of said
supporting shaft, said perforating headpiece comprising a
perforating tip, a penetrating body, and a base aspect;
communication channel controlling means disposed adjacent to said
perforating headpiece on said supporting shaft of said perforator
instrument; a volumetric shaft having two open ends and at least
one sidewall of determinable dimensions, said sheath being (1)
sized at one open end for on-demand placement adjacent to and
aligned closure with said perforating headpiece of said perforator
instrument, (2) substantially annular in configuration over its
axial length, and (3) adapted for protective positioning around and
volumetric spatial envelopment of at least a portion of said
supporting shaft extending from said perforating headpiece of said
perforator instrument, said sheath providing a protective covering
for said enveloped spatial volume then surrounding said supporting
shaft; and position holding means attachable to and detachable from
said volumetric sheath and said supporting shaft of said perforator
instrument for holding said volumetric sheath and the enveloped
spatial volume at a set position around said supporting shaft of
said perforator instrument.
3. A catheterless, piercing introducer assembly suitable for the
introduction and sutureless juncture of a prepared communication
channel to the interior space of an anatomic body part within a
living subject, said introducer assembly comprising: a perforator
instrument comprised of (i) at least one elongated supporting shaft
of predetermined overall dimensions and axial configuration, (ii) a
handle attached at one end to said supporting shaft, (iii) a
perforating headpiece integrally joined to the other end of said
supporting shaft, said perforating headpiece comprising a
perforating tip, a penetrating body, and a base aspect, and
communication channel controlling means disposed adjacent to said
perforating headpiece on said supporting shaft of said perforator
instrument; a volumetric sheath having two open ends and at least
one sidewall of determinable dimensions, said sheath being (1)
sized at one open end for on-demand placement adjacent to and
aligned closure with said perforating headpiece of said perforator
instrument, (2) substantially annular in configuration over its
axial length, and (3) adapted for protective positioning around and
volumetric spatial envelopment of at least a portion of said
supporting shaft extending from said perforating headpiece of said
perforator instrument, said sheath providing a protective covering
for said enveloped spatial volume then surrounding said supporting
shaft; position holding means attachable to and detachable from
said volumetric sheath and said supporting shaft of said perforator
instrument for holding said volumetric sheath and the enveloped
spatial volume at a set position around said supporting shaft of
said perforator instrument; and a prepared communication channel
comprising a linking connector including at least a first portion
of determined dimensions and configuration which is deformable
on-demand, said first portion of said linking connector being
suitable for passage through an aperture and deformation within the
interior space of an anatomic body part whereby said deformation
serves to secure said communication channel to the interior of the
anatomic body part and places said secured communication channel in
fluid flow communication with the interior space of the anatomic
body part, and a second portion of determined dimensions and
configuration which is permanently joined to the sidewall of a
tubular conduit such that said joining retains and secures the
tubular conduit for fluid flow communication; and a tubular conduit
of fixed dimensions and configuration having two open ends and at
least one internal lumen, said tubular conduit being permanently
joined at one open end to said linking connector.
4. The introducer assembly as recited in claim 1, 2 or 3 wherein
said supporting shaft is hollow over at least a portion of its
length.
5. The introducer assembly as recited in claim 1, 2 or 3 wherein
said supporting shaft of said perforating assembly is comprised of
multiple, co-axially arranged, sliding shaft segments.
6. The introducer assembly as recited in claim 1, 2, or 3 wherein
said communication channel comprises an expandable and collapsible
stopper member mounted upon said supporting shaft.
7. The introducer assembly as recited in claim 1, 2, or 3 wherein
said communication channel controlling means comprises an
inflatable and deflatable on-demand balloon appliance disposed
adjacent to said perforating headpiece.
8. The introducer assembly as recited in claim 7 further comprising
a luer fitting in communication with said balloon appliance on said
perforator instrument.
9. The introducer assembly as recited in claim 2 or 3 wherein said
volumetric sheath is divided into a plurality of tangs at one open
end.
10. The introducer assembly as recited in claim 1, 2 or 3 further
comprising an internal lumen within said perforator instrument
which extends through said perforating headpiece and at least a
portion of said supporting shaft.
11. The introducer assembly as recited in claim 1, 2 or 3 wherein
said perforating headpiece further comprises at least one grooved
recess for aligned closure with said sized open end of said
volumetric sheath.
12. The introducer assembly as recited in claim 1, 2 or 3 wherein
said perforating headpiece further comprises a substantially
cone-shaped element disposed upon said base aspect.
13. The introducer assembly as recited in claim 2 or 3 wherein said
volumetric sheath is formed as a substantially inflexible
shell-like protective covering.
14. The introducer assembly as recited in claim 2 or 3 wherein said
volumetric sheath is formed as a flexible fabric-like protective
covering.
15. The introducer assembly as recited in claim 2 or 3 wherein said
volumetric sheath further comprises a flange exteriorly mounted on
the sheath sidewall at one open end.
16. The introducer assembly as recited in claim 3 wherein said
linking connector of said communication channel is formed of a
shape-memory alloy.
17. The introducer assembly as recited in claim 3 wherein said
linking connector is a wire meshwork.
18. The introducer assembly as recited in claim 3 wherein said
linking connector of said communication channel is in substantially
cylindrical form.
19. The introducer assembly as recited in claim 3 wherein said
linking connector of said communication channel is configured in
T-shaped form.
20. The introducer assembly as recited in claim 3 wherein said
linking connector of said communication channel is configured in
L-shaped form.
21. The introducer assembly as recited in claim 3 wherein said
linking connector of said communication channel is configured in
H-shaped form.
22. The introducer assembly as recited in claim 3 wherein said
communication channel further comprises a vascular bypass graft
segment for a blood vessel.
23. The introducer assembly as recited in claim 3 wherein said
communication channel further comprises an access duct for a hollow
organ.
24. The introducer assembly as recited in claim 3 wherein said
communication channel further comprises a tubular conduit formed of
naturally occurring matter.
25. The introducer assembly as recited in claim 3 wherein said
communication channel further comprises a tubular conduit formed of
a synthetic material.
26. A perforator instrument suitable for the introduction and
sutureless juncture of a prepared communication channel to the
interior space of an anatomic body part within a living subject,
said introducer perforator instrument comprising: (i) at least one
elongated supporting shaft of predetermined overall dimensions and
axial configuration, (ii) a handle attached at one end to said
supporting shaft; and (iii) a perforating headpiece integrally
joined to the other end of said supporting shaft, said perforating
headpiece comprising a perforating tip, a penetrating body, and a
base aspect.
27. A volumetric sheath suitable for use within a catheterless,
piercing introducer assembly for the introduction and sutureless
juncture of a prepared connecting conduit apparatus to the interior
space of an anatomic body part within a living subject, said
volumetric sheath comprising: a shell covering having two open ends
and at least one sidewall of determinable dimensions, said shell
covering being (1) sized at one open end for on-demand placement
adjacent to and aligned closure with an introducer instrument; (2)
substantially annular in configuration over its axial length; and
(3) adapted for protective positioning around and volumetric
spatial envelopment of at least a portion of a perforator
instrument, wherein said volumetric sheath provides a protective
covering for said enveloped spatial volume of the perforator
instrument.
28. A method for introduction and sutureless juncture of a prepared
communicating channel to the interior space of an anatomic body
part within a living subject, said method comprising the steps of:
obtaining an introducer assembly comprised of a perforator
instrument including (i) at least one elongated supporting shaft of
predetermined overall dimensions and axial configuration; (ii) a
controlling handle attached at one end to said supporting shaft;
and (iii) a perforating headpiece integrally joined to the other
end of said supporting shaft, said perforating headpiece comprising
a perforating tip, a penetrating body, and a base aspect; and
communication channel controlling means disposed adjacent to said
perforating headpiece on said supporting shaft; preparing a
communicating channel comprising a linking connector including at
least a first portion of determined dimensions and configuration
which is permanently deformable on-demand, said first portion of
said linking connector being suitable for passage through an
aperture and deformation within the interior space of an anatomic
body part whereby said deformation serves to secure said
communicating channel to the interior of the anatomic body part and
places said secured communicating channel in fluid flow
communication with the interior space of the anatomic body part,
and a second portion of determined dimensions and configuration
which is permanently joined to the sidewall of a tubular conduit
such that said joining retains and secures the tubular conduit for
fluid flow communication; and a tubular conduit of fixed dimensions
and configuration having two open ends and at least one internal
lumen, said tubular conduit being permanently joined at one open
end to said linking connector; positioning said prepared
communicating channel around said supporting shaft of said
perforator; introducing said positioned communicating channel using
said introducer assembly to the interior space of an anatomic body
part within a living subject such that said first portion of said
linking connector of said positioned communicating channel becomes
deformed and secures said joined tubular conduit to the interior
space of the anatomic body part for fluid flow communication.
29. A method for introduction and sutureless juncture of a prepared
communicating channel to the interior space of an anatomic body
part within a living subject, said method comprising the steps of:
obtaining an introducer assembly comprised of a perforator
instrument including (i) at least one elongated supporting shaft of
predetermined overall dimensions and axial configuration; (ii) a
controlling handle attached at one end to said supporting shaft;
and (iii) a perforating headpiece integrally joined to the other
end of said supporting shaft, said perforating headpiece comprising
a perforating tip, a penetrating body, and a base aspect; a
volumetric sheath having two open ends and at least one sidewall of
determinable dimensions, said sheath being (1) sized at one open
end for on-demand placement adjacent to and aligned closure with
said perforating headpiece of said perforator instrument, (2)
substantially annular in configuration over its axial length, and
(3) adapted for protective positioning around and volumetric
spatial envelopment of at least a portion of said supporting shaft
extending from said perforating headpiece of said perforator
instrument, said sheath providing a protective covering for said
enveloped spatial volume then surrounding said supporting shaft;
position holding means attachable to and detachable from said
volumetric sheath and said supporting shaft of said perforator
instrument for holding said volumetric sheath and the enveloped
spatial volume at a set position around said supporting shaft of
said perforator instrument; and a prepared communicating channel
comprising a linking connector including at least a first portion
of determined dimensions and configuration which is deformable
on-demand, said first portion of said linking connector being
suitable for passage through an aperture and deformation within the
interior space of an anatomic body part whereby said deformation
serves to secure said communication channel to the interior of the
anatomic body part and places said secured communication channel in
fluid flow communication with the interior space of the anatomic
body part, and a second portion of determined dimensions and
configuration which is permanently joined to the sidewall of a
tubular conduit such that said joining retains and secures the
tubular conduit for fluid flow communication; and a tubular conduit
of fixed dimensions and configuration having two open ends and at
least one internal lumen, said tubular conduit being permanently
joined at one open end to said linking connector; positioning said
prepared communicating channel around said supporting shaft of said
perforator instrument such that said volumetric sheath envelops and
protects said positioned communicating channel; and introducing
said positioned communicating channel using said introducer
assembly to the interior space of an anatomic body part within a
living subject such that said portion of said linking connector of
said positioned communicating channel becomes deformed and secures
said joined tubular conduit to the interior space of the anatomic
body part for fluid flow communication.
Description
PROVISIONAL PATENT APPLICATION
[0001] This invention was first filed as a Provisional Patent
Application on Dec. 9, 1999 as U.S. Application Serial No.
60/169,874.
FIELD OF THE INVENTION
[0002] The present invention is concerned generally with minimally
invasive methods for accessing the vascular system and hollow
organs of the body; and is directed to an assembly and methodology
for creating sutureless vascular anastomoses and hollow organ
communication channels on-demand.
BACKGROUND OF THE INVENTION
[0003] Coronary artery disease is the single leading cause of human
mortality and is annually responsible for over 900,000 deaths in
the United States alone. Additionally, over 3 million Americans
suffer chest pain (angina pectoris) because of it. Typically, the
coronary artery becomes narrowed over time by the build up of fat,
cholesterol and blood clots. This narrowing of the artery is called
arteriosclerosis; and this condition slows the blood flow to the
heart muscle (myocardium) and leads to angina pectoris due to a
lack of nutrients and adequate oxygen supply. Sometimes it can also
completely stop the blood flow to the heart causing permanent
damage to the myocardium, the so-called "heart attack."
[0004] The conventional treatment procedures for coronary artery
disease vary with the severity of the condition. If the coronary
artery disease is mild, it is first treated with diet and exercise.
If this first course of treatment is not effective, then the
condition is treated with medications. However, even with
medications, if chest pain persists (which is usually secondary to
development of serious coronary artery disease), the condition is
often treated with invasive procedures to improve blood flow to the
heart. Currently, there are several types of invasive procedures:
(1) Catheterization techniques by which cardiologists use balloon
catheters, atherectomy devices or stents to reopen up the blockage
of coronary arteries; or (2) Surgical bypass techniques by which
surgeons surgically place a graft obtained from a section of artery
or vein removed from other parts of the body to bypass the
blockage.
[0005] Conventionally, before the invasive procedures are begun,
coronary artery angiography is usually performed to evaluate the
extent and severity of the coronary artery blockages. Cardiologists
or radiologists thread a thin catheter through an artery in the leg
or arm to engage the coronary arteries. X-ray dye (contrast medium)
is then injected into the coronary artery through a portal in the
catheter, which makes the coronary arteries visible under X-ray, so
that the position and size of the blockages in the coronary
arteries can be identified. Each year in U.S.A., more than one
million individuals with angina pectoris or heart attack undergo
coronary angiographies for evaluation of such coronary artery
blockages. Once the blocked arteries are identified, the physician
and surgeons then decide upon the best method to treat them.
[0006] In the surgical correction of vascular disease in the human
body, it is frequently necessary to attach blood vessels to each
other. A native blood vessel may be diseased with conditions that
cause blockages, such as atherosclerosis. In this situation, it is
frequently necessary to reroute the blood that would ordinarily
traverse the diseased vessel via the creation of a vascular bypass.
The conduit used to form this bypass around an obstructed segment
may be another blood vessel native to the patient, such as a vein
or artery harvested from elsewhere in the body; or may be a
man-made conduit of either synthetic or biological material.
Methods for attaching blood vessels to each other include: end to
end attachments, where the result is a linear conduit for blood
flow with the bypassing vessel and the vessel to which it is
attached lying in parallel, in-line with each other; side to side
attachments, where the result is a staggered, linear channel, where
the bypassing vessel and the vessel to which it is attached are in
parallel but offset by the width of one of the blood vessels; and
end to side attachments, where the bypassing vessel meets the
vessel which it is to supply with flow at some angle of less than
180 degrees, and typically approximately 90 degrees and often as a
`T` or `L` or `H` type of connection.
[0007] It is useful here to understand in depth what the
traditional coronary arterial bypass entails and demands both for
the patient and for the cardiac surgeon. In a standard coronary
bypass operation, the surgeon must first make a foot-long incision
in the chest and split the breast bone of the patient. The
operation requires the use of a heart-lung machine that keeps the
blood circulating while the heart is being stopped and the surgeon
places and attaches the bypass grafts. To stop the heart, the
coronary arteries also have to be perfused with a cold potassium
solution (cardioplegia). In addition, the body temperature of the
patient is lowered by cooling the blood as it circulates through
the heart-lung machine in order to preserve the heart and other
vital organs. Then, as the heart is stopped and a heart-lung
machine pumps oxygenated blood through the patient's body, the
surgeon makes a tiny opening into the front wall of the target
coronary artery with a very fine knife (arteriotomy); takes a
previously excised saphenous vein (a vein from a leg) or an
internal mammary artery (an artery from the chest); and sews the
previously excised blood vessel to the coronary artery. Synthetic
substitutes for a naturally occurring blood vessel are available
and often used.
[0008] To create the anastomosis at the aorta, the ascending
thoracic aorta is first partially clamped using a curved vascular
clamp to occlude the proper segment of the ascending aorta; and a
hole is then created through the front wall of the aorta to anchor
the vein graft (or synthetic substitute) with sutures. The graft
bypasses the blockage in the coronary artery and restores adequate
blood flow to the heart. After completion of the grafting, the
patient is taken off of the heart-lung machine and the patient's
heart starts beating again. Most of the patients can leave the
hospital in about 6 days after the surgical procedure.
[0009] It will be noted that coronary artery bypass surgery is
considered a definitive method for treating coronary arterial
disease because all kinds of obstructions cannot be treated by
angioplasty; and because a recurrence of blockages in the coronary
arteries even after angioplasty is not unusual. Also coronary
artery bypass surgery usually provides for a longer patency of the
grafts and the bypassed coronary arteries in comparison with the
results of an angioplasty procedure. However, traditional coronary
artery bypass surgery is a far more complicated procedure, having
need of a heart-lung machine and a stoppage of the heart. Also, it
is a more invasive procedure and is more expensive to perform.
Therefore, cardiac surgeons have recently developed an alternative
to the standard bypass surgery, namely "minimally invasive bypass
operation" (MIBO) in order to reduce the risks and the cost
associated with the surgery. Also, the MIBO is performed without
use of a heart-lung machine or the stopping of the heart. Some of
the current methods for creating these connections include handsewn
surgical anastomoses, where a surgeon places a series of surgical
knots around the circumference of the vascular connection, forming
a liquid-tight connection; as well as a variety of vascular staple
type devices, where mechanical apparatii are used to effect the
connection, generally using a two or more part apparatus comprising
the staple introducer and an `anvil` type of part against which the
staples are curved back, bent, or otherwise fixed into position
around the circumference of the vascular connection.
[0010] Another approach has been the introducer catheter based
methods and apparatii for the creation of an end-to-side vascular
connection (anastomosis) using an implanted device comprising a
deformable flange or retained portion and deformable flange, to
which a biological or synthetic conduit has been pre-attached
ex-vivo; and a variety of configurations for introducer mechanisms
and systems for inserting this implantable device into the side of
the blood vessel. For the purposes of this description, the blood
vessel is generally defined as the blood vessel which is punctured
and which receives the collar or deformable flange portion of the
implantable device into its internal lumen. The receiving blood
vessel may be either the source or the recipient of blood flow,
depending on the required and existing direction of blood flow.
Merely illustrative and representative of these introducer catheter
based vascular bypass graft systems and techniques are U.S. Pat.
Nos. 6,007,544; 5,797,920, and 5,676,670 all of which describe a
catheter apparatus and methods for creating a bypass on-demand
between an unobstructed and obstructed blood vessel using a
deformable cuff connector and graft segment in tandem; as well as
Nos. 6,036,702; 6,013,190; 6,001,124; 5,972,017; 5,941,908; and
5,931,842 which illustrate a range and variety of T-shaped,
L-shaped, H-shaped, and oblique-angle graft connectors available
for medical use.
[0011] A key advantage of the methods and devices described in
these issued U.S. Patents is the ability to create a vascular
anastomosis while maintaining high blood pressures (systemic and
greater) within the receiving blood vessels. These devices and
systems therefore allow the creation of the proximal anastomosis in
Coronary Artery Bypass Grafting procedures (CABG) to be performed
without need to exclude blood from the aorta where the site of
anastomosis is to be. This in turn obviates the need for use of the
cardiopulmonary bypass machine, a device (which takes over the
pumping of the blood through the body while the proximal aorta is
made blood pressure free); and eliminates the Aortic Side Biting
Clamp, a semicircular clamp which pinches off a portion of the
aorta, creating a blood pressure free pocket to which the handsewn
graft attachment was previously made. Use of both the machine and
the side biting clamp result in trauma to the aorta; and such
trauma causes, among other things, the release of embolic debris
from the aortic wall (a cause of stroke, cognitive deterioration,
and other morbidities), and/or damage to the lining of the aorta
which can result in separation of the layers of the aorta,
resulting in dissection, a potentially lethal complication.
Frequently also, the time required for surgery is shortened because
intricate in-vivo suturing techniques are not required to ensure
acceptable patency rates and no leakage at the handsewn anastomoses
of the new grafts.
[0012] There remains, however, a long-standing and continuing need
for additional improvements in bypass technique and apparatus which
would allow surgeons to perform more simple multiple bypass
procedures in a minimally invasive way using tubular grafts as
vascular shunts; and, in particular, a need remains for a
catheterless method to place one or more vein grafts or other
conduits proximally to the aorta and distally to the coronary
artery without using a heart-lung machine, and without stopping the
heart, and without using the side biting clamp.
[0013] In addition to the foregoing difficulties, there exists also
a very different medical problem in the non-vascular realm, in
particular with regard to obtaining in-vivo access to a hollow
organ within the body of a living subject.
[0014] Access to the interior of a hollow organ is often needed for
a number of reasons, depending on the organ system. These accesses
may be required to supply food substances into the stomach or small
bowel in patients who are unable to eat (gastrostomy and
jejunostomy, respectively); and/or to eliminate wastes or the
buildup of pressure in other organs whose outlets are blocked or
dysfunctional, as may occur in the obstructed urinary system
(nephrostomy or cystostomy), respiratory system (tracheostomy), or
the pathologically dilated cecum (proximal large bowel and
cecostomy). Occasionally, a hollow organ space or body cavity is
filled with infected material, and it is clinically desirable to
create a communication channel allowing the infected contents to be
drained rather than surgically removing the infected organ. Such a
situation may occur within the gallbladder, and the communication
channel so created is then called a cholecystostomy. Occasionally,
a communication channel is required between hollow body cavities,
such as between a cyst originating in the pancreas, and the inside
of the stomach. Periodically as well, a communication channel is
required into a spatial area or zone within the body, such as the
peritoneal cavity, in order to instill fluids for dialysis. Thus, a
number of different devices and systems now exist for the on-demand
creation of these types of communication channels between hollow
organs; or between body cavities and the skin surface; or between
two hollow organs within the body.
[0015] It will be noted that many hollow organ surgical procedures
are now performed using trocars and cannulas. Originally these
devices were used for making a puncture and leaving a tube to drain
fluids. As technology and surgical techniques advanced, it became
possible to insert surgical instruments through the cannulas to
perform invasive procedures through openings less than half an inch
in diameter, whereas in the past these procedures required
incisions of many inches. By using a trocar and minimizing the
incision, the stress and loss of blood suffered by patients was
reduced. A range and variety of trocar assemblies are known. These
are represented by U.S. Pat. Nos. 4,601,710; 5,545,150; 5,122.122;
5,112,321; and 6,063,099.
[0016] Today, surgical trocars are most commonly used in
laparoscopic surgery. Prior to use of the trocar, the surgeon will
usually introduce a Veress needle into the patient's abdominal
cavity. The Veress needle has a stylet which permits the
introduction of gas into the abdominal cavity. After the Veress
needle is properly inserted, it is connected to a gas source and
the abdominal cavity is insufflated to an approximate abdominal
pressure of 15 mm Hg. By insufflating the abdominal cavity,
pneumoperitoneum is created separating the wall of the body cavity
from the internal organs.
[0017] A trocar is then typically used to puncture the body cavity.
The piercing tip or obturator of the trocar is inserted through the
cannula; and the cannula partially enters the body cavity through
the incision made by the trocar. The obturator is then removed from
the cannula. An elongated endoscope or camera may be then inserted
through the cannula to view the body cavity; or surgical
instruments may be inserted through the cannula to perform
ligations or other procedures.
[0018] A great deal of force is often required to cause the
obturator to pierce the wall of the body cavity. When the piercing
tip breaks through the cavity wall, resistance to penetration
ceases and the tip may reach internal organs or blood vessels, with
resultant lacerations and potentially serious injury. For this
reason, a variety of trocar designs have been developed with spring
loaded shields surrounding the piercing tip of the obturator. Once
the piercing tip of the obturator has completely pierced the body
cavity wall, the resistance of the tissue to the spring loaded
shield is reduced and the shield springs forward into the body
cavity and covers the piercing tip. The shield thereby protects
internal body organs and blood vessels from incidental contact with
the piercing tip and resultant injury. Such trocars including
various safety shield designs are illustrated by U.S. Pat. Nos.
4,535,773; 4,654,030; and 4,601,710; 5,104,382; 4,902,280;
5,030,206; 5,545,150; and 5,350,393.
[0019] Clearly both the realms of performing vascular bypass graft
procedures and accessing the interior of a hollow organ can and
would benefit from structural devices and improved surgical methods
which offer simplified means for joining a prepared communication
channel to a blood vessel or a hollow organ on-demand in a
minimally invasive way. Moreover, were such simplified means
developed such that the presently existing requirement and
necessity of using a catheter or cannula is eliminated and avoided,
such an improvement would be generally recognized in the medical
arts as a major advance and unusual benefit to both the surgeon and
his patient.
SUMMARY OF THE INVENTION
[0020] The present invention has multiple formats and applications.
A first format is a catheterless, piercing introducer assembly
suitable for the introduction and sutureless juncture of a prepared
communication channel to the interior space of an anatomic body
part within a living subject, said introducer assembly
comprising:
[0021] a perforator instrument comprised of
[0022] (i) at least one elongated supporting shaft of predetermined
overall dimensions and axial configuration,
[0023] (ii) a controlling handle attached at one end to said
supporting shaft; and
[0024] (iii) a perforating headpiece integrally joined to the other
end of said supporting shaft, said perforating headpiece comprising
a perforating tip, a penetrating body, and a base aspect; and
[0025] communication channel controlling means disposed adjacent to
said perforating headpiece on said supporting shaft of said
perforator instrument.
[0026] A second format is a catheterless, piercing introducer
assembly suitable for the introduction and sutureless juncture of a
prepared communication channel to the interior space of an anatomic
body part within a living subject, said introducer assembly
comprising:
[0027] a perforator instrument comprised of
[0028] (i) at least one elongated supporting shaft of predetermined
overall dimensions and axial configuration
[0029] (ii) a controlling handle attached at one end to said
supporting shaft; and
[0030] (iii) a perforating headpiece integrally joined to the other
end of said supporting shaft, said perforating headpiece comprising
a perforating tip, a penetrating body, and a base aspect.
[0031] communication channel controlling means disposed adjacent to
said perforating headpiece on said supporting shaft of said
perforator instrument;
[0032] a volumetric sheath having two open ends and at least one
sidewall of determinable dimensions, said sheath being
[0033] (1) sized at one open end for on-demand placement adjacent
to and aligned closure with said perforating headpiece of said
perforator instrument,
[0034] (2) substantially annular in configuration over its axial
length, and
[0035] (3) adapted for protective positioning around and volumetric
spatial envelopment of at least a portion of said supporting shaft
extending from said perforating headpiece of said perforator
instrument, said sheath providing a protective covering for said
enveloped spatial volume then surrounding said supporting shaft;
and
[0036] position holding means attachable to and detachable from
said volumetric sheath and said supporting shaft of said perforator
instrument for holding said volumetric sheath and the enveloped
spatial volume at a set position around said supporting shaft of
said perforator instrument.
[0037] A third format of the present invention is a catheterless,
piercing introducer assembly suitable for the introduction and
sutureless juncture of a prepared communication channel to the
interior space of an anatomic body part within a living subject,
said introducer assembly comprising:
[0038] a perforator instrument comprised of
[0039] (i) at least one elongated supporting shaft of predetermined
overall dimensions and axial configuration
[0040] (ii) a controlling handle attached at one end to said
supporting shaft; and
[0041] (iii) a perforating headpiece integrally joined to the other
end of said supporting shaft, said perforating headpiece comprising
a perforating tip, a penetrating body, and a base aspect;
[0042] communication channel controlling means disposed adjacent to
said perforating headpiece on said supporting shaft of said
perforator instrument;
[0043] a volumetric sheath having two open ends and at least one
sidewall of determinable dimensions, said sheath being
[0044] (1) sized at one open end for on-demand placement adjacent
to and aligned closure with said perforating headpiece of said
perforator instrument,
[0045] (2) substantially annular in configuration over its axial
length, and
[0046] (3) adapted for protective positioning around and volumetric
spatial envelopment of at least a portion of said supporting shaft
extending from said perforating headpiece of said perforator
instrument, said sheath providing a protective covering for said
enveloped spatial volume then surrounding said supporting
shaft;
[0047] position holding means attachable to and detachable from
said volumetric sheath and said supporting shaft of said perforator
instrument for holding said volumetric sheath and the enveloped
spatial volume at a set position around said supporting shaft of
said perforator instrument; and
[0048] prepared communication channel comprising
[0049] a linking connector including at least
[0050] a first portion of determined dimensions and configuration
which is deformable on-demand, said first portion of said linking
connector being suitable for passage through an aperture and
deformation within the interior space of an anatomic body part
whereby said deformation serves to secure said communication
channel to the interior of the anatomic body part and places said
secured communication channel in fluid flow communication with the
interior space of the anatomic body part, and
[0051] a second portion of determined dimensions and configuration
which is permanently joined to the sidewall of a tubular conduit
such that said joining retains and secures the tubular conduit for
fluid flow communication; and
[0052] a tubular conduit of fixed dimensions and configuration
having two open ends and at least one internal lumen, said tubular
conduit being permanently joined at one open end to said linking
connector.
BRIEF DESCRIPTION OF THE FIGURES
[0053] The present invention may be better appreciated and more
easily understood when taken in conjunction with the accompanying
drawing, in which:
[0054] FIG. 1 is a perspective illustration of a first preferred
embodiment of the introducer assembly comprising the present
invention;
[0055] FIGS. 2A and 2B are illustrations of the perforator
instrument comprising a component part of the introducer assembly
of FIG. 1;
[0056] FIGS. 3A and 3B are illustrations of the volumetric sheath
comprising a component part of the introducer assembly of FIG.
1;
[0057] FIGS. 4A and 4B are illustrations of the position holding
means comprising a component part of the introducer assembly of
FIG. 1;
[0058] FIG. 5 is an illustration of the inter-relationship between
the volumetric sheath of FIGS. 3A and 3B and the position holding
means of FIGS. 4A and 4B;
[0059] FIGS. 6A, 6B, and 6C are illustrations of a linking
connector and tubular conduit which comprise a prepared
communication channel to be used with the introducer assembly of
FIG. 1;
[0060] FIG. 7 is an illustration of the inter-relationship between
the prepared communication channel of FIGS. 6B and 6C and the
perforator instrument of FIGS. 2A and 2B;
[0061] FIGS. 8A and 8B are perspective and partial cross-sectional
illustrations of the prepared communication channel of FIGS. 6B and
6C when positioned within and part of the complete introducer
assembly of FIG. 1;
[0062] FIG. 9 is an illustration of the complete introducer
assembly of FIGS. 8A and 8B when approaching a sidewall of a blood
vessel or hollow organ in-vivo;
[0063] FIG. 10 is an illustration of the complete introducer
assembly after piercing and penetrating through an aperture in the
sidewall of a blood vessel or hollow organ;
[0064] FIG. 11 is an illustration of the advancement forward of the
prepared communication channel into the internal spatial volume of
a blood vessel or hollow organ using the complete introducer
assembly;
[0065] FIG. 12 is an illustration of the deployment in-situ and the
sutureless securing of the prepared communication channel within
the internal spatial volume of a blood vessel or hollow organ;
[0066] FIG. 13 is an illustration of the partial rearward
withdrawal of the introducer assembly after the communication
channel has been deployed and secured to a blood vessel or hollow
organ;
[0067] FIG. 14 is an illustration of the joined and secured
communication channel after the introducer assembly has been
removed;
[0068] FIG. 15 is an illustration of one alternative embodiment for
the perforating headpiece of the perforator instrument of FIG.
2;
[0069] FIG. 16 is an illustration of a second alternative
embodiment for the perforating headpiece of the perforator
instrument of FIG. 2;
[0070] FIGS. 17A and 17B are cross-sectional and perspective
illustrations of the perforating headpiece of FIG. 16;
[0071] FIG. 18 is an illustration of one alternative embodiment for
the volumetric sheath of FIG. 3;
[0072] FIG. 19 is an illustration of the relationship between the
prepared communication channel of FIG. 6C when used in the
perforating headpiece of FIGS. 16 and 17 and the volumetric sheath
of FIG. 18;
[0073] FIG. 20 is an illustration of a second alternative
embodiment for the volumetric sheath of FIG. 3;
[0074] FIG. 21 is an illustration of one alternative embodiment of
the introducer assembly of FIG. 1;
[0075] FIG. 22 is a detail partial cross-sectional illustration of
the alternative introducer assembly of FIG. 21;
[0076] FIG. 23 is a perspective illustration of a second preferred
embodiment of the introducer assembly comprising the present
invention;
[0077] FIG. 24 is an illustration of the perforator instrument
comprising a component part of the introducer assembly of FIG.
23;
[0078] FIG. 25 is an illustration showing details of the coaxial
supporting shafts in the perforator instrument of FIG. 24;
[0079] FIG. 26 is an illustration showing details of the
perforating headpiece in the perforator instrument of FIG. 24;
[0080] FIG. 27 is an illustration of the volumetric sheath
comprising a component part of the introducer assembly of FIG.
23;
[0081] FIGS. 28A and 28B are illustrations of the communication
channel controlling means comprising part of the introducer
assembly of FIG. 23;
[0082] FIG. 29 is a partial cross-sectional illustration of the
prepared communication channel of FIG. 6C positioned within the
complete introducer assembly of FIG. 23;
[0083] FIG. 30 is a cross-sectional illustration of the complete
introducer assembly of FIG. 29 after piercing and penetrating
through an aperture in the sidewall of a blood vessel or hollow
organ;
[0084] FIG. 31 is an illustration of a deployment at will within
the internal spatial volume of a blood vessel or hollow organ and
the securing of the communication channel to the blood vessel or
hollow organ;
[0085] FIG. 32 is an illustration of the partial rearward
withdrawal of the introducer assembly of FIG. 23 after the
communication channel has been deployed and secured to a blood
vessel or hollow organ;
[0086] FIG. 33 is an illustration of the secured communication
channel after the introducer assembly of FIG. 23 has been
removed;
[0087] FIGS. 34A and 34B are illustrations of a first linking
connector;
[0088] FIGS. 35A and 35B are illustrations of a second linking
connector;
[0089] FIGS. 36A and 36B are illustrations of a third linking
connector;
[0090] FIGS. 37A and 37B are illustrations of a fourth linking
connector;
[0091] FIGS. 38A and 38B are illustrations of an unbranched tubular
conduit;
[0092] FIG. 39 is an illustration of a multi-branched tubular
conduit;
[0093] FIGS. 40A and 40B are illustrations of a first type of
tubular conduit construction;
[0094] FIGS. 41A and 41B are illustrations of a second type of
tubular conduit construction;
[0095] FIGS. 42A and 42B are illustrations of a third type of
tubular conduit construction;
[0096] FIGS. 43A and 43B are illustrations of a fourth type of
tubular conduit construction;
[0097] FIG. 44 is a cross-sectional illustration of a first style
of internal lumen for a tubular conduit;
[0098] FIG. 45 is a cross-sectional illustration of a second style
of internal lumen for a tubular conduit;
[0099] FIG. 46 is a cross-sectional illustration of a third style
of internal lumen for a tubular conduit; and
[0100] FIG. 47 is a cross-sectional illustration of a fourth style
of internal lumen for a tubular conduit.
DETAILED DESCRIPTION OF THE INVENTION
[0101] The present invention is an introducer assembly and surgical
technique for creating a single channel bypass or multiple channel
bypasses on-demand between blood vessels such as the aorta and an
obstructed coronary artery in-vivo; and for creating an access
channel or duct to the interior space of a hollow organ in-vivo.
The present invention can utilize a synthetic tubular conduit as a
communication channel; or a previously excised vascular segment as
a grafted tubular conduit; or any other biological conduit created
via hormonally or genetically modified cellular means. In addition,
the invention employs a catheterless introducer assembly and system
in combination with the prepared communication channel to create
single or multiple conduit shunts or grafts in-vivo. The grafted
tubular conduit will then be used either to deliver blood from a
primary blood vessel, around the obstruction, into a secondary
artery or vein in order to increase and/or maintain proper blood
circulation in the living body; or provide an access duct or portal
into a hollow organ in the body of a living subject. A number of
substantial advantages and major benefits are therefore provided by
the present invention, some of which include the following:
[0102] 1. The present invention provides the means for surgeons to
perform single or multiple channel grafts in a minimally invasive
manner. The methodology permits the surgeon to utilize either
synthetic tubular conduits as communication channels or previously
excised veins or arteries or other biological conduit as bypass
grafts; and allows the surgeon to place each of the tubular
conduits from a primary unobstructed artery (such as the aorta) to
a secondary obstructed artery (such as the obstructed coronary
artery) without using a heart-lung machine and without need for
stopping the heart during the surgery.
[0103] 2. The present methodology also avoids the prior need to
exclude blood from the section of the primary vessel to which the
graft is being attached. In the case of CABG surgery, for example,
there would be no further need for an aortic side biting clamp--a
device with rough semi-circular jaws that isolates a centrally
located zone of the aorta from the blood and blood pressure then
present in the rest of the aorta.
[0104] 3. The present invention simplifies the complexity of
conventional vascular bypass or hollow organ surgery and makes the
surgery less invasive. Moreover, the introducer assembly and
technique provides the ability to create multiple communication
channels using a sutureless and catheterless procedure which not
only shortens the conventional operation time for surgery but also
makes the surgery safer and more cost effective.
[0105] 4. The present invention is suitable for creating a single
conduit graft or multiple conduit grafts in any medical situation,
condition, or pathology in which there is a need for to direct
blood flow to a specific blood vessel or vascular area or body
region. The cause or source of the medical problem may be an
obstruction in a blood vessel; or a narrowing or thickening of a
blood vessel wall; or a diminution or narrowing of a vascular
section in a particular blood vessel. Each of these medical
conditions has its particular cause, origin, or source; and each of
these pathologies, though different in origin, causes a similar
effect overall--a loss of blood flow and blood pressure within the
blood vessel. Accordingly, the present invention is deemed useful
and desirable to overcome any of these particular medical
conditions and instances where there is a demonstrated need for
increased blood pressure and blood volume flow within a particular
blood vessel in the body, and where that blood may be supplied from
a suitable adjacent vessel using the present system.
[0106] 5. The present apparatus and methodology can be employed to
create a bypass conduit between any two blood vessels. In many
instances, the bypass conduit will be made between a primary
unobstructed artery and a secondary obstructed artery, a typical
example being a bypass between the ascending aorta and an
obstructed coronary artery. However, a bypass shunt may also be
created between any two veins (such as between the portal vein and
the inferior vena cava); or between an artery and a vein (such as
between the superior vena cava and a pulmonary artery) between the
different chambers of the heart, or between the heart chambers and
blood vessels. Equally important, although the primary focus of the
present invention is the thoracic cavity and the recognized need
for bypass conduits among the blood vessels found therein, the
present apparatus and methodology may be employed anywhere in the
human body where there is a need for increased vascularization or
revascularization of the local region. The sole limitation,
therefore, is a means of access for the catheter apparatus, the
introducer system, and the methodology to be performed by the
skilled surgeon, or interventional radiologist, or other medical
specialist.
[0107] 6. The introducer assembly and method of use provides
on-demand duct access to the interior of a hollow organ in a
variety of applications. These grafted ducts provide access to
supply food substances into the stomach or small bowel in patients
who are unable to eat (gastrostomy and jejunostomy, respectively);
and/or as a channel to eliminate wastes or the buildup of pressure
in other organs whose outlets are blocked or dysfunctional, as may
occur in the obstructed urinary system, respiratory system, or the
pathologically dilated. Also, when a hollow organ or cavity is
filled with infected material, the introducer system creates a
communication channel for egress, thereby allowing the infected
contents to be drained rather than surgically removing the infected
organ or cavity. Such a situation typically occurs within the
gallbladder and the communication channel so created is then called
a cholecystostomy. In addition, the system will provide a
communication channel between hollow body cavities, such as between
a cyst originating in the pancreas, and the inside of the stomach
or between ventricles of brain and peritoneum or vascular system;
and when a communication channel is required to be placed into a
spatial area or zone within the body, such as the peritoneal
cavity, in order to instill fluids for dialysis.
[0108] In order to better appreciate and more clearly understand
the introducer assembly and the system of intended usage, the
invention as a whole will be described as first and second
preferred embodiments which describe both the requisite and
optional component parts and subassemblies in detail; and also
present a series of alternative embodiments and features which can
be optionally employed at will in addition to or in place of
pertinent parts in either of the preferred embodiments described
herein.
[0109] I. A First Preferred Embodiment
[0110] A first preferred format and embodiment of the introducer
assembly is exemplified and illustrated by FIGS. 1-14 respectively.
As shown therein, FIGS. 1-8 identify the preferred introducer
assembly in its minimal and optional component parts; while FIGS.
9-14 respectively illustrate the intended method of usage and
system which uses the introducer assembly to achieve a sutureless
juncture of a prepared communication channel to a blood vessel or
to the interior of a hollow organ.
[0111] The introducer assembly as a whole is illustrated by FIGS. 1
and 2. As seen therein, the optimized introducer assembly is
comprised of a perforator instrument 10; and the communication
channel controlling means 40 which appears as an inflatable and
deflatable on-demand balloon appliance in this preferred
embodiment; a volumetric sheath 50; and sheath position holding
means which appear in this preferred embodiment as the grasping
member 70. The introducer assembly exemplified by FIG. 1 is in
completely assembled form; comprises each of the requisite and
optional component parts and sub-assemblies in its appropriate
placement and position; and shows the entire optimized apparatus in
a state ready for immediate usage. Details of the individual
component parts of the introducer assembly are shown by FIGS. 2-8
respectively.
[0112] FIG. 2 shows the minimal introducer assembly in detail which
comprises only the perforator instrument 10 and the balloon
appliance 40 which serves as one specific means for controlling and
deploying a prepared communication channel. As illustrated by FIGS.
2A and 2B, the perforator instrument 10 of the minimalist
introducer assembly is comprised of at least one elongated
supporting shaft 12 of predetermined overall dimensions and axial
length having two ends 14, 16; and has a internal lumen 18. Knob
handle 15 is attached at the end 16 of the supporting shaft 12; and
a perforating headpiece 30 is joined to the supporting shaft at the
other shaft end 14. The perforating headpiece 30 is integrally
joined to the end 14 of the supporting shaft 12 and itself
comprises a perforating tip 32, a penetrating body 34, and a base
aspect 36.
[0113] The perforator instrument 10 is thus itself an assembly of
parts which provides a knob handle for the surgeon and a cutting
headpiece suitable for penetrating the sidewall tissue of a blood
vessel or hollow organ and forming an aperture in-situ.
[0114] Disposed adjacent to the perforating headpiece 30 on the
supporting shaft 12 of the perforator instrument 10 is an
inflatable and deflatable on-demand balloon appliance 40. In this
minimalist format and first preferred embodiment, the balloon
appliance 40 structurally serves as communication channel
controlling means for the deployment of the introducer assembly as
a whole; and provides the primary apparatus for controlling the
positioning of a previously prepared communication channel which,
after proper placement within the assembly, will serve either as a
vascular bypass graft or an access duct in-vivo.
[0115] The balloon appliance 40--the communication channel
controlling means in this embodiment--is comprised of an expandable
and deflatable balloon 42 whose interior volumetric space can be
increased and decreased on demand repeatedly without difficulty; an
inflation line 44 joined to the interior space of the balloon 42;
and a luer lock fitting 48 joined to the inflation line 44 but
positioned adjacent to the knob handle 15. The luer lock fitting 48
provides the direct communication means for introducing a inflation
fluid from an external source (not shown) into the inflation line
44 through which the inflation fluid will be carried and
transported into the interior volumetric space of the balloon 42.
By adding fluid through or allowing fluid to flow out of the luer
lock fitting 48, the degree of inflation or deflation for the
balloon appliance 40 can be controlled and maintained at will.
[0116] The volumetric sheath 50, an optional but highly desirable
structure of the introducer assembly, is illustrated by FIGS. 3A
and 3B respectively. The optional volumetric sheath 50 has two open
ends 52, 54 and at least one sidewall 56 of predetermined
dimensions. The volumetric sheath 50 is sized at the open end 52
for on-demand placement adjacent to and aligned closure with the
perforating headpiece 30 of the perforator instrument 10. In
addition, the optional volumetric sheath 50 is substantially
annular in configuration over its axial length but is desirably
constricted at the open end 52 to conform to the particular
dimensions of the perforating headpiece 30. The essential purpose
and function of the volumetric sheath 50 is protection such that
its internal spatial volume 58 over its axial length becomes
available and adapted for protective positioning around and
volumetric spatial envelopment of at least a portion of the
supporting shaft 12 which extends from the perforating headpiece 30
of the perforator instrument 10.
[0117] As shown in FIG. 1 previously, the optional volumetric
sheath 50 when properly positioned provides a protective covering
and envelope for the spatial volume and ambient environment then
surrounding the supporting shaft 12; and any contents (including a
prepared communication channel which is then positioned within the
internal spatial volume 58 of the volumetric sheath 50) will become
protectively surrounded and enveloped by the sheath sidewall 56
over the entirety of the axial length for the configured volumetric
sheath 50. For the introducer assembly as a whole, particularly as
depicted by FIG. 1, the volumetric sheath 50 provides the
protective envelopment of an ambient environment spatial volume and
all its interior contents which then surround the supporting shaft
12 and the introducer assembly as an integrated unit.
[0118] The optional position holding means 70 and its intended
function within the preferred introducer assembly is illustrated by
FIGS. 4 and 5 respectively. FIGS. 4A and 4B each illustrate the
grasping member 70 which is the specific embodiment of the optional
position holding means in this assembly; while FIG. 5 shows the
interrelationship between the grasping member 70 and the volumetric
sheath 50 as intended by the assembly of parts.
[0119] As shown by FIGS. 4A and 4B, the grasping member 70
comprises a grip 72; a shaft mounting 74 configured for disposition
around the support shaft 12 of the perforator instrument 10; and a
sheath positional end fitting 76 which is annular or circular in
overall configuration and dimensioned to fit snugly in a friction
holding position with the open end 54 of the volumetric sheath 50.
It will be noted and appreciated also that the shaft mounting 74 is
itself substantially circular in configuration and is comprised of
a flange 75 and a encircled aperture 77 through which the
supporting shaft 12 will pass axially.
[0120] When properly aligned with the optional volumetric sheath
50, the overall result is illustrated by FIG. 5. Clearly, the open
ends 52, 54 of the volumetric sheath 50 are in alignment with the
grasping member 70; and the entire internal spatial volume 58 of
the volumetric sheath 50 is encompassed by the attachment of the
position holding grasping member 70 at the end 54. The grasping
member thus provides position holding means and maintenance for the
volumetric sheath within the introducer assembly over most of its
axial length.
[0121] The arrangement of each of the requisite and optional
component parts illustrated by FIGS. 2-5 is thus shown properly
aligned and assembled as a preferred structural apparatus by FIG.
1. As the grasping member 70 is advanced forward or pulled rearward
over the supporting shaft 12 of the perforating instrument 10, the
volumetric sheath 50 will concomitantly be advanced forward or
pulled rearward as a consequence. Thus, at any moment or instance
of use, the volumetric sheath 50 as a whole and its internal
spatial volume 58 as well as any contents to be found within the
internal spatial volume itself can be advanced to and beyond the
perforating headpiece 30 or pulled rearward to reveal the component
parts of the perforator instrument. In this manner the perforating
headpiece 30 can be alternatively and repeatedly exposed or hidden
within the internal spatial volume 58 of the volumetric sheath
50.
[0122] The purpose and function of the introducer assembly is to
provide for a catheterless and sutureless juncture of a prepared
communication channel to the interior of a blood vessel or a hollow
organ in-vivo. For descriptive purposes, the prepared communication
channel is briefly illustrated by FIGS. 6A, 6B, and 6C which show
the proper parts of a prepared communicating channel to be used
within the introducer assembly. The essential parts are briefly
illustrated by FIG. 6; but a far more detailed description of the
major forms and alternative embodiments of communicating channels
as a manufactured article are subsequently disclosed herein as well
as illustrated by FIGS. 34-47 inclusive.
[0123] As shown by FIG. 6, a prepared communication channel 80 is
comprised of a linking connector 82 and a tubular conduit 90. The
tubular conduit 90 is any tube or hollow channel having two open
discrete ends 92, 94; at least one tubular sidewall 96; and an
internal lumen 98 of fixed spatial volume. The tubular conduit 90
accordingly also has an internal sidewall surface 95 which is
co-extensive with the internal lumen 98; and an external sidewall
surface 97 of predetermined dimensions and overall configuration.
Further details regarding the tubular conduit 90 are described
hereinafter.
[0124] The linking connector 82 is shown as an open wire meshwork
construction in FIGS. 6B and 6C respectively. The linking connector
includes at least a first cuff portion 84 of predetermined
dimensions and configuration which is superelastic and/or
thermo-elastic, thermoplastic and deployable on-demand. The first
cuff portion 84 is configured for passage through an aperture in
the wall of a blood vessel or a hollow organ; is superelastic; and
is deformable and deployable on-demand whereby the act of
deformation in-situ within the interior volumetric space of a blood
vessel or hollow organ serves to secure the joined tubular conduit
interior of the blood vessel or hollow organ and places the secured
tubular conduit in fluid flow communication with the interior
volumetric space of the blood vessel or hollow organ proper. The
linking connector also includes a second conduit retaining portion
86 of determined dimensions and configuration which is joined to
the sidewall 96 of the tubular conduit 90 such that the joining
retains and secures the tubular conduit 90 for fluid flow
communication purposes.
[0125] The juncture of the linking connector 82 may be made either
at the external sidewall surface 97 as shown in FIG. 6B or
alternatively at the internal sidewall surface 95 as illustrated by
FIG. 6C. In many instances the juncture of the second conduit
retaining portion 86 is desirably done within the internal lumen 98
by direct joining to the internal sidewall surface 95. However, any
format of juncture [using staples, sutures or any other permanent
means for joining] is suitable for use within the introducer
assembly. Accordingly, the prepared communication channel 80 as a
prepared article of manufacture is shown equally by FIG. 6B or 6C
without distinction or meaningful difference.
[0126] For purposes of further description the communication
channel 80 will be prepared in the manner illustrated by FIG. 6C
where the linking connector 82 is joined along its retaining
portion 86 to the internal sidewall surface 95 of the tubular
conduit 90. The placement of the prepared communication channel as
embodied by FIG. 6C is shown in FIG. 7.
[0127] As illustrated by FIG. 7, the prepared communication channel
80 is intended to be positioned over perforator instrument 10. This
positioning is accomplished by inserting the perforating headpiece
30 and the supporting shaft 12 of the perforator instrument 10 into
the internal lumen 98 of the tubular conduit 90 via the open end
94. The perforating headpiece 30 is then extended through the
internal lumen 98 until it exits the communication channel 80 at
the other tubular conduit end, thereby concomitantly also passing
through the joined linking connector 82 in its entirety. Supporting
shaft 12 will then hold and support the entirety of the prepared
communication channel 80 in this position within the introducer
assembly; and the volumetric sheath with grasping member 70 is
subsequently placed around prepared communication channel 80. This
results in the completely arranged introducer assembly illustrated
by FIG. 8.
[0128] As seen therein, FIG. 8A shows a perspective view of the
complete introducer assembly with the prepared communication
channel 80 contained within the internal spatial volume 58 of the
volumetric sheath 50. To illustrate better the aligned positioning
within the introducer assembly, a cross sectional view along the
axis AA' of FIG. 8A is provided and shown in detail via FIG. 8B. As
seen therein, the prepared communication channel 80 is housed
within the internal spatial volume 58 of the volumetric sheath 50;
is completely enveloped by the volumetric sheath 50; and is
protected by the covering of the volumetric sheath 50 while
supported on the supporting shaft 12 of the perforator instrument
10. The first cuff portion 84 has been placed adjacent the
penetrating body 34 of the perforating headpiece 30 while the
second conduit retaining portion 86 joined to the internal sidewall
surface 95 of the tubular conduit 90 appears positioned around the
balloon appliance 40. As noted previously, the balloon appliance
may be inflated and deflated at will; and by inflating the balloon
appliance 40 in this setting, the inflated balloon will thus hold
the entirety of the prepared communication channel 80 firmly and
indefinitely and prevent the channel from moving linearly until
such time that the balloon 40 is deflated again. Equally important,
the entirety of the perforator instrument 10 including the
perforating headpiece 30 may be advanced forward or pulled rearward
at will at any time while positioned within the internal lumen 98
of the tubular conduit 90 and the joined linking connector 82. In
this manner, the entire axial length of the perforator instrument
may be advanced or withdrawn while the prepared communication
channel 80 remains in a single position within the enveloped
spatial volume 58 provided by the protective volumetric sheath
50.
[0129] The complete introducer assembly illustrated by FIG. 8 is
shown in the intended application and usage for the introduction
and sutureless juncture of a prepared communication channel by
FIGS. 9-14 respectively. These FIGS. 9-14 inclusive illustrate that
the anatomic body part penetrated is typically a blood vessel or a
hollow organ 100. The targeted body part 100 has at least two walls
102, 104 and an internal spatial organ volume 108. This is
illustrated in its generic form within FIGS. 9-14.
[0130] FIG. 9 shows the complete introducer assembly as it
approaches the front sidewall 102 of the blood vessel or hollow
organ. It will be seen therein that the open end 52 of the
volumetric sheath is placed adjacent to and in aligned closure with
the perforating headpiece 30 of the perforator instrument. The
prepared communication conduit 80 lies entirely within the internal
spatial volume 58 of the volumetric sheath 50 as does the balloon
appliance 40 and the supporting shaft 12 of the perforator
instrument. Also, as shown by FIG. 10, the balloon appliance is in
the deflated state thereby permitting the entirety of the
perforator instrument 10 and the penetrating tip 32 in particular
to pass out of the enveloped spatial volume provided by the
volumetric sheath 50; then to cut into the sidewall 102; and
thereby form an aperture 110. The introducer assembly as a whole is
then advanced forward through the newly formed aperture 110.
[0131] FIG. 10 also shows the position of the prepared
communication channel as an integrated unit through the aperture
110 in the front wall 102 of the blood vessel or hollow organ. As
seen therein, the volumetric sheath 50 housing the linking
connector 82 has been pushed forward such that the first cuff
portion 84 lies positioned within the internal spatial volume of
the blood vessel or hollow organ 100; and the perforating headpiece
30 and the deflated balloon appliance 40 have also been extended
into the internal spatial volume 108 and thus support the prepared
communication channel in this position.
[0132] The balloon appliance then is preferably inflated by
introducing fluid via the luer lock fitting (not shown) which is
passed through the inflation line and inflates the balloon interior
space 42 thereby holding the prepared communication channel 80 in
place within the aperture 110 itself. This is illustrated by FIG.
11.
[0133] Accordingly, the linking connector 82 which has been
permanently joined to the internal sidewall surface 95 of the
tubular conduit 90, is then allowed to deform on-demand and deploy
in-situ. This event is shown by FIG. 12. The individual acts of
deformation and deployment of the first cuff portion 84 within the
internal spatial volume 108 of the blood vessel or hollow organ 100
thus serve to secure the prepared communication channel 80 to the
interior of the anatomic body part; and concurrently places the
secured communication channel 80 in fluid flow communication with
the internal spatial volume 108 of the blood vessel or hollow
organ. Moreover, while the act of deployment within the internal
spatial volume 108 occurs as illustrated by FIG. 12, the tubular
conduit permanently joined to the second conduit retaining portion
86 remains in place and in a somewhat expanded state by
superelasticity, thermoelasticity, and/or balloon inflation. This
retained portion 86 permanently joined to the sidewall of the
tubular conduit retains and secures the tubular conduit 90 for
unobstructed fluid flow communication.
[0134] The final stages of the method and system are illustrated by
FIGS. 13 and 14 respectively. FIG. 13 shows the introducer assembly
being withdrawn after deflation of the balloon from within the
internal lumen 98 of the tubular conduit 90. FIG. 14 illustrates
the final desired result and shows the sutureless juncture of the
prepared communication channel 80 in position through the aperture
110 in the front wall 102 of the blood vessel or hollow organ 100.
As seen therein, the prepared communication channel is joined to
the interior space of the blood vessel or hollow organ; is secured
in a fluid-tight manner to the internal spatial volume 108 of the
blood vessel or hollow organ interior; and is in fluid flow
communication with the interior space of this anatomic body part.
The linking connector 82 shows the first cuff portion 84 in the
deformed state within the interior space of the blood vessel or
hollow organ and shows that this in-situ deformation acts to secure
the tubular conduit 90 to the interior spatial volume of the blood
vessel or hollow organ and places the prepared communication
channel in fluid flow communication for whatever purpose is desired
by the surgeon for his patient.
II. Alternative Embodiments And Formats
[0135] The first preferred embodiment described previously herein
is merely one structural assembly format whose component parts may
be alternatively configured for a variety of purposes. To
demonstrate the variety of alternative embodiments and structural
formats, the following structural designs and constructions are
provided. It will be expressly understood, however, that these
described alternative embodiments and constructions are merely
illustrative of the wide range and broad variety of alternatives
which is well within the skill of the ordinary person skilled in
this technical field; and that the described formats are merely
representative examples of many other constructions which may be
used equally well for a particular medical application or specific
patient purpose.
[0136] Alternative embodiment 1:
[0137] A first alternative design and construction facilitates the
passage and removal of the prepared communication channel over the
axial length of the perforator instrument and concurrently allows
for easy removal of the perforator instrument as well as the
introducer assembly as a whole after the communication channel has
been joined in-situ to the interior spatial volume of a blood
vessel or hollow organ. For this purpose a first alternative
construction for the perforating headpiece of the perforator
instrument is provided as illustrated by FIG. 15. As seen therein,
the perforating headpiece 130 now comprises a perforating cutting
tip 132, a penetrating body 134 of diminished dimensions and size
in comparison to that described previously herein; has a base
aspect 136 which is now serving as a surface for a cone-shaped end
element 138. As before, the perforating headpiece 130 is integrally
joined to the supporting shaft 12 of the perforator instrument. In
this construction, the point of juncture and integral union for the
perforating headpiece 130 as a unit is at the cone-shaped end
element 138.
[0138] The benefit and major advantage of this construction is that
the cone-shaped base end element 138 is tapered along its sides
140; and that this tapered sidewall 140 for the cone-shaped end
element 138 will not only permit easier passage and withdrawal
through the linking connector; but also, if necessary, dilate the
linking connector structure to permit an unobstructed withdrawal of
the perforating headpiece 130 after the communication channel has
been joined to the blood vessel or hollow organ interior space. If
desired, the entire external surface of the perforating headpiece
and the sides 140 of the cone-shaped base end element 138 in
particular may be covered with a hydrophilic coating in order to
provide a more slippery surface and ensure an easier passage.
[0139] Alternative embodiment 2:
[0140] This second alternative embodiment and structural
construction is illustrated by FIGS. 16-19 respectively. There are
two essential parts to this second alternative embodiment. The
first is revealed by FIGS. 16, 17A, and 17B respectively which
reproduce in part the perforating headpiece 130 illustrated by FIG.
15 and described herein previously. In this alternative
construction, the perforating headpiece 130 again includes a
perforating tip 132, a penetrating body 134, a base aspect 136, and
a cone-shaped end element 138; but also now comprises a plurality
of recesses which individually appear as a groove 165 and a furrow
167 within the penetrating body portion 134 and the base aspect 136
respectively.
[0141] Particular details of this structural construction are shown
by FIGS. 17A and 17B respectively. As seen therein the recessed
groove 165 is circumferentially extensive and deep within the
penetrating body 134. Similarly, the recessed furrow 167
circumferentially penetrates sharply through the base aspect 136
and the interior of the penetrating body 134. The cross sectional
view illustrated by FIG. 17A shows the manner in which the recessed
groove 165 and recessed furrow 167 exist in depth; in comparison,
the cross-sectional view of the perforating headpiece 130 (looking
forward from the supporting shaft towards the perforating tip 132)
of FIG. 17B shows the concentric ring nature and annular alignment
of the recessed groove 165 in comparison to the recessed furrow
167.
[0142] This second alternative embodiment of the perforating
headpiece 130 having recessed groove 165 and recessed furrow 167 is
intended to be employed with a modified construction for the
volumetric sheath illustrated by FIG. 18. In this modified design
structure and construction, the volumetric sheath 150 has a front
open end 152 which is configured as multiple segmented tangs 154.
The multiple segmented tangs 154 are preferably evenly spaced
around the circumference of the open end 152 and are desirably
biased such that the preferred positioning of the segmented tangs
is in the open position as shown in FIG. 18. The multiple biased
segmented tangs 154 when compressed annularly into the closed
position will form a single circular and unified open end 152; and
while in the closed position will provide a unitary opening 152 for
the entirety of the volumetric sheath 150 despite being constructed
as multiple segmented pieces. In this manner, the segmented tangs
154 will remain preferably in the open, biased position; but at
will can be compressed to form a single circular or annular front
end opening 152 and access to the interior spatial volume of the
volumetric sheath 150.
[0143] The positioning of the multiple segmented tangs 154 in the
closed position is intended for placement within the recessed
groove 165 of the perforating headpiece 130 illustrated previously
in FIGS. 16 and 17 respectively. The segmented tangs 154 will fit
into and be held by the recessed groove 165; and form itself within
the interior space of the groove as the unitary annular opening
152. This is shown by FIG. 19. In addition, the recessed furrow 167
will receive and hold the first cuff portion 84 of the linking
connector 82 after it has been permanently joined to the tubular
conduit as the prepared communication channel. The placement of the
linking connector 82 at the first cuff portion 84 into the recessed
furrow 167 is also illustrated in FIG. 19. This linking connector
placement thus allows a further degree of certainty and safety for
the prepared communication channel after it has been positioned
around the supporting shaft of the perforator instrument and has
been enveloped by the volumetric sheath 150.
[0144] Alternative Embodiment 3:
[0145] A third alternative construction provides a variant format
for the volumetric sheath of the introducer assembly. This third
alternative construction is illustrated by FIG. 20 and utilizes in
part the volumetric sheath structure illustrated by FIG. 18 and
described in detail previously herein. In this alternative
embodiment, however, the variant structure includes inner sleeve
160 which is of predetermined dimensions and substantially
cylindrical configuration. The inner sleeve 160 comprises a open
front end 162, an open rear end 164, and a cylindrically-shaped
grip 161 joined to the rear end 164. Not only does the inner sleeve
160 slide forward and rearward at will within the interior volume
of the volumetric sheath 150; but as the inner sleeve 160 is slid
forward towards the segmented tangs 154, the front end 162 engages
the segmented tangs 154 of the volumetric sheath 150 and forces the
tangs open as a consequence of the physical engagement. This allows
quick and easy removal of the volumetric sheath 150 from the
introducer assembly, especially after the segmented tangs 154 have
been placed in the closed position forming a unitary annular front
end.
[0146] One major benefit and advantage of this alternative
construction using the inner sleeve 160 as illustrated within FIG.
20 is that this format allows the volumetric sheath 150, the outer
sheath covering, to be made of a woven synthetic textile material
which is prepared in advance and coated with a non-porous polymer
coating. The polymer coating would preferably bias the woven
textile material of the outer volumetric sheath in the closed
position in which the multiple segmented tangs would reform as a
single annular opening. Thus, as the inner sleeve is advanced
within the outer volumetric sheath, it would effectively expand the
polymer coated woven textile material and permit removal of the
outer volumetric sheath in a far easier fashion.
[0147] Clearly this type of construction and format allows for a
volumetric sheath which is composed or designed using a woven
synthetic textile material; and thus allows a fabric type
construction and a fabric arrangement for the outer sheath which
acts as the protective barrier and covering around the perforating
instrument. This type of woven textile construction and embodiment
for the volumetric sheath, with or without the presence and use of
an inner sleeve as shown within FIG. 20, is merely one variant of
the many different constructions and materials which may be
employed with the introducer assembly as a whole.
[0148] Alternative embodiment 4:
[0149] A fourth alternative design and construction is illustrated
by FIGS. 21 and 22 respectively. This format and structural design
permits the surgeon to utilize the Seldinger technique, a favored
procedure for this kind of surgery. In this technique, a guidewire
is positioned in the targeted blood vessel or hollow organ wall;
and it is this guidewire which is then utilized as the means for
precise guidance and placement of the introducer assembly as a
whole at that precise anatomic location. For this purpose the
alternative construction of FIGS. 21 and 22 is added to the first
preferred embodiment previously described herein.
[0150] As illustrated, the perforator instrument is comprised of
the supporting shaft 12, the perforating headpiece 30 and the knob
handle 15. However, within the internal lumen 18 of the support
shaft 12, a second hollow lumen 180 exists which extends and passes
through the axial length of the perforator instrument 10. This is
shown by FIG. 21. The guidewire hollow lumen 180 extends through
the perforating headpiece 30, through the supporting shaft 12 over
its axial length, and exits adjacent to the handle 15 where it is
joined to flexible tubing 182. The flexible tube 182 is joined to
the hollow lumen 180 at the juncture point 186; and the flexible
tube 182 provides an entry portal 184 through which the guidewire
exits. A cross sectional view of this internal arrangement, the
perforating headpiece end, is illustrated by FIG. 22.
[0151] The use of the Seldinger technique and the ability to pass a
guidewire from the anatomic targeted site at the blood vessel wall
or hollow organ wall directly through the perforating tip of the
perforating headpiece and continuously through the entirety of the
introducer assembly provides a major advantage and benefit for the
assembly.
III. A Second Preferred Embodiment
[0152] A second preferred embodiment of the introducer assembly and
system which is the present invention is illustrated by FIGS. 23
through 33 respectively. This second preferred embodiment conforms
to and satisfies the minimal component part requirements of each
and every introducer assembly as a whole; but this preferred
embodiment is a far more elaborate and sophisticated engineering
design and construction.
[0153] An overview of this second preferred embodiment is provided
by FIG. 23 which shows the introducer assembly 202 as an arranged
apparatus comprising a perforator instrument 210, volumetric sheath
250, and position holding means configured as a pistol-grip
mounting 204.
[0154] A detailed view of the perforator instrument 210 and the
means for controlling the communication channel configured as a
cuff stopper/holder subassembly 270 are shown by FIGS. 24, 25, 26,
and 27 respectively. As seen therein, the perforator instrument 210
is comprised of two coaxial support shafts 212 and 222. The longer
and innermost support shaft 212 has two ends 214, 216 and an
internal lumen 218. A knob handle 215 is joined to the support
shaft 212 at the end 216. At the other shaft end 214 is attached to
a perforating headpiece 230.
[0155] The second coaxial support shaft 222 is somewhat larger in
overall diameter over its axial length than counterpart support
shaft 212. This second support shaft 222 has two ends 224, 226; and
a control knob 225 joined to the shaft 222 at the end 226. When
coaxially joined together the support shaft 222 serves as the
external or outermost shaft whereas the innermost support shaft 212
lies internally and coaxially within its diameter. This
relationship is illustrated by FIGS. 26 and 24 respectively.
[0156] The perforating headpiece 230 is seen in detail within FIG.
26 and is comprised of a multi-faceted cutting tip 232, a
penetrating body 234, a base aspect 236, a recessed furrow 267, and
a cone-shaped base end element 238. The cone-shaped base end
element is collapsible to accommodate the positioning of the cuff
into the cone-shaped base element and expandible to accommodate the
withdrawal of the headpiece through the deployed cuff. This
perforating headpiece 230 is integrally joined to the supporting
shaft 212 at the front shaft end 214.
[0157] One advantage of the perforating headpiece 230 is the
multi-faceted cutting tip 232 which provides multiple faces and
cutting edges 232. The number of multiple faces and edges is
typically from 3-5 edges; and such a multi-faced and multi-edged
bladed tip is deemed to be more effective as a cutting tool than a
single bladed tip. In addition, it is recognized that single bladed
or edged perforating tips often produce lacerations in the blood
vessel or hollow organ wall which subsequently may fracture or
fragment. For this reason it is believed that multi-faced and
multi-edged cutting tips are preferred and would be ideal in most
use applications.
[0158] The communication channel controlling means is specifically
embodied as connector stopper/holder subassembly 270 and is best
illustrated by FIGS. 26, 28A, and 28B. As seen therein, the
collapsed position for the stopper/holder 270 is illustrated by
FIG. 28A while the open or expanded position is illustrated by FIG.
28B. As seen therein, the stopper subassembly 270 comprises
expandable and collapsible segments 274, each of which is mounted
on a segment supporting strip 276. The stopper subassembly 270 is
joined to coaxial supporting shaft via the support strips 276; and
passes coaxially over the inner supporting shaft 212 over its axial
length within the internal lumen 301 of the outer supporting shaft
300. When the outer supporting shaft 300 is withdrawn rearward, the
stopper 270 expands into its open position as shown; and when outer
supporting shaft 300 is advanced forward over the supporting strips
276, the stopper segments 274 are pulled together forcing the
stopper subassembly into the collapsed state as shown by FIG.
28.
[0159] The purpose of the stopper/holder subassembly 270 is to
provide a structural backstop for the linking connector (then
already joined to the tubular conduit as the prepared communication
channel); and to support the back of the linking connector during
withdrawal of the perforating headpiece 230. The stopper/holder
assembly 270 is expanded during placement of the linking connector;
and the expanded stopper subassembly engages the end of the linking
connector as a back stop. When properly, the linking connector
(already joined to the tubular conduit) will thus rest against the
front face 280 of the stopper subassembly; and the stopper
subassembly thereby provides the means for controlling the prepared
communication conduit while positioned within the introducer
assembly. Once the prepared communication conduit is deployed into
the interior space of a blood vessel or hollow organ target, the
stopper/holder subassembly 270 is reduced into the collapsed state
and allows the subassembly to be withdrawn rearward as part of the
perforator instrument 210.
[0160] The volumetric sheath 250 of the second preferred embodiment
is shown in detail by FIG. 27. As seen therein, the volumetric
sheath 250 comprises two open ends 252, 254; a sidewall 256; and an
internal spatial volume 258. In this embodiment for the volumetric
sheath 250, a flange 260 is mounted on the exterior surface of the
volumetric sheath at the open end 252. This end flange 260 has an
extended annular rib 262 and a rib perimeter 264 of predetermined
dimensions. At the other open end 254 is a sidewall alignment hole
266 which is utilized in the positioning of the volumetric sheath
250 within the introducer assembly by acting to stop the forward
motion of the introducer assembly and to limit entry of the
assembly to only that degree which is needed.
[0161] Finally, the position holding means which are attachable to
and detachable from the volumetric sheath of FIG. 27, and used for
holding the volumetric sheath 250 and its enveloped spatial volume
at a set position around the two supporting shafts 300, 212, 222,
is best seen in FIG. 23. As illustrated therein, the position
holding means is embodied as a pistol-grip mounting 204 having a
mounted body 206 and a finger grip 208. The volumetric sheath 250
is internalized at the end 254 and held in aligned position via the
sidewall alignment hole 266; and the pistol-grip mounting holds the
volumetric sheath via the alignment hole 266 in the complete
introducer assembly.
[0162] One additional feature is provided as an extra point of
manipulation and control for the introducer assembly as a whole.
This is shown as the knob 285 and appears in FIGS. 23 and 28 to
best advantage. The controller knob 285 is mounted on the exterior
surface of the outermost support shaft 300. In aligned position,
the control knob 285 is located within the pistol-grip mounting
204; allows for manipulation of the outer most supporting shaft
300; and is a controller for placing the stopper subassembly 270
from an open position into a collapsed position and subsequently
back into an open position repeatedly on-demand. This is an
optional feature but a preferred item in this embodiment because it
provides precision control for the connector stopper subassembly
without major change in position of either coaxial supporting shaft
212 and 222 respectively.
[0163] When a prepared communication channel 80 is positioned
within this introducer assembly 250, the complete system
methodology is ready to be used by the surgeon. A cross sectional
detail of the complete introducer assembly is provided by FIG. 29.
As seen therein, the communication channel 80 is positioned within
the internal spatial volume 258 of the volumetric sheath 250.
Placed within the internal lumen 98 of the tubular conduit 90 is
the perforator instrument 210 including the perforating headpiece
230, the inner supporting shaft 222, the stopper subassembly 270 in
the expanded state, and the outer supporting shaft 300. By use of
the stopper subassembly 270 which is positioned against the second
retained portion 86 of the linking connector 82, full manipulative
control of the communication channel as a prepared article of
manufacture is maintained throughout.
[0164] The deployment and method of usage for this second preferred
embodiment is shown by FIGS. 30-33 respectively. The complete
introducer assembly illustrated within FIG. 29 and generally by
FIG. 23 is employed as shown to penetrate the wall of a targeted
blood vessel or hollow organ. This is shown by FIG. 30. The
perforating headpiece 230 has penetrated into the interior spatial
volume of the targeted blood vessel or organ while the end flange
260 of the volumetric sheath 250 remains against the exterior
surface of the target. The end flange 260 serves to stop the
forward motion of the introducer assembly as a whole by providing a
larger diameter sheath than the aperture formed by the perforating
headpiece 230. After the perforation aperture has been made, the
perforating headpiece 230 alone is advanced forward thereby
releasing the first cuff portion 84 from the recessed furrow 267.
The linking connector is now free to deform in full and to be
deployed completely in-situ within the internal spatial volume of
the penetrated target vessel or organ. This is illustrated by FIG.
31.
[0165] Subsequently, the perforating headpiece 230 may be withdrawn
through the internal lumen of the joined and secured communicating
channel. This is illustrated by FIG. 32 and is achieved by
manipulating the controlling knobs 215 and 225 rearward. The knob
285 is then advanced to collapse the stopper subassembly. The
entire introducer assembly is then pulled back using the finger
grip 208 of the pistol-grip mounting 204, the deformed linking
connector and tubular conduit joined and secured to the internal
spatial volume of the targeted blood vessel or hollow organ. This
result is illustrated by FIG. 33.
IV. The Prepared Communication Channel
A. The Linking Connector
[0166] An essential component part of the prepared communicating
channel is the presence and use of a superelastic and thermoelastic
linking connector preferably comprised of a shape-memory alloy
composition.
[0167] The shape-memory metal alloy compositions preferably used
with the present invention constitute conventionally known blends
and formulated metallic mixtures of nickel and titanium which
undergo a phase transition--that is, a molecular rearrangement of
atoms, molecules or ions within a lattice structure--due to a
temperature change. The unique capability of shape-memory alloys is
that these alloys are extremely elastic, flexible, and durable;
these alloys change shape or configuration as a direct consequence
of a change in temperature; and the alloy composition "remembers"
its earlier and specifically prepared shape because the phase
change affects its structure on the atomic level only, without
disturbing the arrangement of the molecules which would otherwise
be irreversible.
[0168] Superelasticity and Thermoelasticity
[0169] When these shape-memory alloys are intentionally superheated
far above their transition temperature (either electrically or by
external heat), a stretched temperature transformed alloy format
results which contracts and exerts considerable force; and the
temperature transformed alloy composition will become memory-shaped
(deformable in-situ) in a fixed specific configuration. Afterwards,
when cooled to below its transition temperature, the prepared alloy
composition presents superelasticity properties which allow the
alloy to be bent and shaped into other configurations while
retaining the fixed "memory" of the particular shape in the earlier
superheated condition, the thermoelastic properties. Thus, these
shape-memory alloy compositions are recognized as being both
superelastic and thermoelastic compositions of matter.
[0170] Alloy Formulations
[0171] At least twenty different formulations of these superelastic
and thermoelastic alloys are conventionally known, all of these
comprising different mixtures of nickel and titanium in varying
percentage ratios [Design News, Jun. 21, 1993 issue, pages 73-76].
These metal alloys are conventionally utilized today in the
manufacture of diverse products. For example, a range of different
shape-memory alloy wires are commercially available in diameters
from 0.001-0.010 inches [Dynalloy, Inc., Irvine, Calif.]. In
addition, surgical anchors having such superelastic properties and
formed by two or more arcs of wire strands (which can withstand
strains exceeding 10%) have been developed [Mitek Surgical
Products, Inc., Norwood, Mass.]. Also, blood clot filters formed of
superelastic shape-memory alloy wires are commercially sold for
implantation in large blood vessels such as the vena cava [Nitinol
Medical Technologies, Inc., Boston, Mass.]. While these
commercially available products illustrate the use of one or more
superelastic and thermoelastic properties as particular articles, a
more general listing of conventionally known properties and
characteristics for shape-memory alloy compositions is provided by
Table 1 below.
1TABLE 1 Conventionally Known Properties of Shape-Memory
Alloys.sup.1 Transformation Properties Transformation Temperature
-200 to -110.degree. C. Latent Heat Of 5.78 cal/g Transformation
Transformation Strain (for polycrystaline material) for a single
cycle 8% maximum for 10.sup.2 cycles 6% for 10.sup.5 cycles 4%
Hysteresis* 30 to 50.degree. C. Physical Properties Melting point
1300.degree. C. (2370.degree. F.) Density 6.45 g/cm.sup.3 (0.0233
lb/in.sup.3) Thermal Conductivity austenite 0.18 W/cm .multidot.
.degree. C. (10.4 BTU/ft .multidot. hr .multidot. .degree. F.)
martensite 0.086 W/cm .multidot. .degree. C. (5.0 BTU/ft .multidot.
.degree. F.) Coefficient of Thermal Expansion austenite 11.9
.times. 10.sup.-6/.degree. C. (6.11 .times. 10.sup.-6/.degree. F.)
martensite 6.6 .times. 10.sup.-6/.degree. C. (3.67 .times.
10.sup.-6/.degree. F.) Specific Heat 0.20 cal/g .multidot. .degree.
C. (0.20 BTU/lb .multidot. .degree. F.) Corrosion Performance**
excellent Electrical Properties Resistivity (.rho.) [resistance =
.rho. .multidot. length/ cross-sectional area] austenite .about.100
.mu..OMEGA. .multidot. cm (.about.39.3 .mu..OMEGA. .multidot. in)
martensite .about.80 .mu..OMEGA. .multidot. cm (.about.31.5
.mu..OMEGA. .multidot. in) Magnetic Permeability <1.002 Magnetic
Susceptibility 3.0 .times. 10.sup.6 emu/g Mechanical Properties
Young's Modulus*** austenite .about.83 GPa (.about.12 .times.
10.sup.6 psi) martensite .about.28 to 41 GPa (.about.4 .times.
10.sup.6 to 6 .times. 10.sup.6 psi) Yield Strength austenite 195 to
690 MPa (28 to 100 ksi) martensite 70 to 140 MPa (10 to 20 ksi)
Ultimate Tensile Strength fully annealed 895 MPa (130 ksi) work
hardened 1900 MPa (275 ksi) Poisson's Ratio 0.33 Elongation at
Failure fully annealed 25 to 50% work hardened 5 to 10% Hot
Worability quite good Cold Workability difficult due to rapid work
hardening Machineability difficult, abrasive techniques are
preferred *Values listed are for a full martensite to austenite
transition. Hysteresis can be significantly reduced by partial
transformation or temary alloys. **Similar to 300 series stainless
steel or titanium. ***Highly nonlinear with temperature
[0172] All the different specific formulations and metallic blends
comprising nickel and titanium which yield a deformable,
thermoelastic, shape-memory alloy composition are suitable for use
when practicing the present methodology. All of these shape-memory
alloys rely on a crystal phase change from a higher temperature
Austenite form to a lower temperature Martensite form to accomplish
the memory effect. The cubic Austenite phase behaves much like
ordinary metals as it deforms. In contrast, the complex crystal
Martensite form can be found by reversible movement of twin
boundaries to change the average "tilt" or strain in each segment
of the alloy. The overall strain can be eliminated by releasing the
stress, by maintaining it if it is not thermally stable (the
superelastic effect), or by heating the alloy to change it back to
Austenite form (shape-memory effect).
[0173] The crystal transformation of shape-memory alloy
compositions is, by definition, thermoelastic--i.e., it progresses
in one direction on cooling below the transition temperature and in
the other direction upon heating above the transition temperature.
The amount of transformation change versus temperature, measured
either as the percent of Martensite form or the strain in a
constantly stressed element, is a function of and can be plotted
against temperature (.degree. C.) directly; and the change from one
phase (and identifiable shape) to another typically occurs in a
narrow temperature range (often 5-10.degree. C.). Hysteresis takes
place before the reverse transformation occurs.
[0174] The amount of strain accommodated due to the movement of
twin boundaries, differs in each metallic alloy blending system. In
the nickel-titanium system for example, up to 8% reversible tensile
strain is available; however, to guarantee a long life use, the
strain is often limited to 4-5%.
[0175] The stress-strain behavior of shape-memory alloy
compositions is employed to help explain the shape-memory effect.
For instance, Martensite is much easier to deform than Austenite.
Therefore, one can deform the alloy while cold with much less force
than when heated to change it back into Austenite form. As a
result, the alloy converts thermal energy to mechanical work at
high forces.
[0176] Fixing the Memory-Shaped Configuration in the Metal
Alloy
[0177] To prepare and fix the particular (or desired) shape to be
"remembered" when the alloy undergoes a temperature phase
transition, the alloy composition must be superheated initially to
about 500.degree. C. (or roughly 930.degree. F.) for an hour while
held in the fixed shape and position to be memorized. During the
superheating process, the native alloy blend enters what is called
the Austenite phase--a rigid lattice of nickel atoms surrounded by
titanium alloys. Then, as the alloy metal cools below its
transition temperature (which will vary with the percentage
proportions of nickel and titanium), the alloy composition adopts
the Martensite phase, in which the nickel and titanium atoms assume
a very different arrangement--one that is very easy to bend and
deform. Subsequently, when the deformed metallic alloy is reheated
to the chosen transition temperature range between 25-35.degree.
C., thermal motion causes the atoms to snap back into the Austenite
phase, thereby restoring the fixed memory-shaped configuration of
the object [Invention & Technology, Fall 1993, pages
18-23].
[0178] For purposes of practicing the present invention, it is most
desirable that the shape-memory alloy composition be prepared in a
metallic blend and formulation such that the temperature transition
phase occurs at a temperature less than about 35.degree. C.; but
greater than about 25.degree. C.; and preferably be in the range
from about 30-35.degree. C. This preferred 30-35.degree. C.
transition phase temperature range is dictated by the demands of
the human body which maintains a normal temperature at about
37.degree. C. (98.6.degree. F.); and typically shows a normal
temperature range and variance of one or two degrees Celsius above
and/or below this normative temperature standard. It is for this
reason that the broad temperature range be about 25-35.degree. C.
and the preferred temperature transition occur in the range of
30-35.degree. C.; but that such transformation into the intended
and fixed memory-shaped configuration occur at least by a
temperature of 35.degree. C. to insure a safety margin of medical
usefulness.
B. Thermoelastic Properties of the Linking Connector
[0179] The shaped connector configurations of the thermoelastic
alloy composition at temperatures less than about 25-35.degree. C.
(a temperature below its transition temperature at which the alloy
exists in the Martensite phase) may take a broad variety of
different lengths, diverse dimensions, and disparate overall
configuration. Merely exemplifying the range and diversity of
three-dimensional forms into which the alloy compositions can be
shaped into a linking connector structure at temperatures below
25.degree. C. are those illustrated by FIGS. 34-37 respectively.
For purposes of practicing the present invention, FIGS. 34-35 are
considered more preferred embodiments and constructions of the
shaped alloy structures, while FIGS. 36-37 respectively represent
formats and fabrications of the deformed in-situ alloy compositions
in less frequently utilized shaped configurations.
[0180] Effect of Temperatures Less than and Greater than
25-35.degree. C.
[0181] As illustrated and embodied by FIGS. 34A and 34B, the
deformable in-situ, thermoelastic linking connector is a
substantially cylindrical-shaped collar which is open at each of
its ends 302, 304. The linking connector 300 is hollow; is
substantially round or oval (in cross-sectional view); and has a
determinable first configuration and dimensions initially which are
deformed at will into a second memory-shaped configuration when
placed at a temperature greater than about 25-35.degree. C.
[0182] It is most desirable that the thermoelastic material
constituting the sidewall 306 of the connector 300 be prepared and
shaped as a first-configuration along the axis AA' as shown within
FIG. 34A; and that the thermoelastic material constituting the
sidewall 306 be an open-weave pattern of a memory-shaped alloy
rather than take form as a solid mass of thermoelastic alloyed
material. For this reason, the sidewall 306 illustrated within FIG.
34A appears in the first configuration as an open meshwork of wires
308 which are intertwined to form a substantially hexagonal
pattern. This open meshwork of wires 308 provides the desired
resiliency, flexibility, and memory-shaped deformation capability
(particularly along the axis AA') such that the first or upper cuff
portion of the sidewall 306 will become deformed and flared
outwardly on-demand to yield the memory-shaped second configuration
constituting the flared-lip deformity 310 shown by FIG. 34B.
[0183] It will be recognized and appreciated that the deformed cuff
portion shown by FIG. 34B is merely the result of removing the cuff
structure from a temperature less than 25-35.degree. C. and placing
it into a temperature environment greater than about 35-35.degree.
C. Thus, solely as a consequence of the change in temperature, the
uppermost cuff portion 309 of the open meshwork of wires 308 above
the axis AA' has become deformed in-situ such that the upper
sidewall 309 adjacent to the open end 302 has expanded outwardly,
flared, and become bent into a curved lip configuration in the
memory-shaped deformed state. Note that FIG. 34B shows the upper
deformation in the fully deployed state; while the open meshwork of
wires constituting the lower retaining portion 307 of the sidewall
306 at the other open end 304 remains relatively stable and
substantially unaltered in its original shape and state.
Alternatively, however, the lower retaining sidewall portion 307
can be made to expand or diminish slightly so that it will
annularly fit more tightly outside of or within the conduit wall.
The deformation in-situ thus is controlled thermally and the forces
at the upper curve sidewall portion from the AA' axis cause the
outwardly extending, flared lip result as the fully deployed state.
Moreover, the resulting flared lip zone 310 retains structural
strength and resiliency as an open meshwork of superelastic wires
despite having been deformed in-situ and deployed in full. The
ability of the first cuff portion to be deformed and deployed in
the manner illustrated by FIGS. 34A and 34B respectively is an
attribute and characteristic of each embodiment and construction
for the thermoelastic linking connector.
[0184] The construction and design for the linking connector is an
example of the engineering principle that structural form at will
follow intended function. As a component part of the system
apparatus and methodology for attaching a tubular conduit in-vivo,
the functions of the linking connector are twofold in nature: (1)
the temperature-deformable linking connector is intended to engage
and become joined to either a synthetic duct prosthesis or a
previously excised vascular segment which will serve as the tubular
conduit in-vivo; and (2) the temperature-deformable linking
connector is intended to be positioned within the internal lumen of
an unobstructed major blood vessel (such as the aorta) or within a
hollow organ cavity such that a first portion of the connector wall
becomes positioned and secured within the internal lumen (the blood
flow channel) of the unobstructed blood vessel or the interior of
the hollow organ permanently in a fluid-tight manner. Thus, as
illustrated by the embodiments of FIGS. 34A and 34B, the uppermost
cuff region 309 of the alloy comprising the linking connector will
be deformed on-demand merely by warming the article to a
temperature greater than 25-35.degree. C.; and such deformation
when deployed into a flared outwardly bent form will become secured
within the lumen of the unobstructed artery or vein or the cavity
of the hollow organ. Concomitantly, the retained portion 307 will
remain permanently joined in substantially unaltered form to the
tubular conduit.
[0185] Several attributes and characteristics are commonly to be
shared among all embodiments and constructions of the thermally
deformable and deployable on-demand linking connector. These
include the following:
[0186] (a) Only a portion of the alloy material constituting the
memory-shaped linking connector need be thermally deformable and
deployable on-demand. For convenience and greater facility in
achieving such temperature initiated deformation in the degree and
at the time desired, it is preferred that the alloy composition
forming the linking connector be an open weave or wire meshwork
rather than a solid sheet alloy mass, which is considered to be
more difficult to deform in a thermally-controlled manner. There
is, however, no substantive restriction or limitation as such at
any time or under any intended use circumstances which necessitates
an avoidance of a solid sheet of material, either as a single alloy
sheet or as a laminated plank of alloy material. Accordingly, the
choice of whether to use an open wire meshwork or a solid sheet of
alloy material is left to the discretion of the user.
[0187] (b) The thermoelastic linking connector need only be
comprised of superelastic, resilient and flexible metallic alloy
matter. A number of different alloys of varying formulations may be
usefully employed when making a deformable memory-shaped linking
connector suitable for use with the present invention. Among the
desirable alloy formulations are those characterized by Table 1
above.
[0188] (c) After the deformable in-situ and deployable at will
linking connector has been manufactured using shape-memory alloy
materials, the first configured cuff portion structure (prior to
thermal deformation) may be covered to advantage with one or more
biocompatible coatings. These biocompatible coatings are intended
to water tighten the article and to facilitate the sewing of the
tubular conduit to the linking connector as well as to reduce the
interactions of the immune system and tissue reaction with the
prepared communicating channel after it has been secured in their
appropriate locations in-vivo. Such biocompatible coatings are
conventionally known; will reduce the severity and duration of
immune or tissue reactions which frequently disrupt or interfere
with grafts; and are considered desirable in a majority of use
instances in order to minimize the body reaction to surgery. A
representative listing of biocompatible coatings deemed suitable
for use with the deformable thermoelastic connector is provided by
Table 2 below.
2TABLE 2 Biocompatible Coatings High temperature pyrongen-free
carbon; Polytetrafluoroethylene (PTFE) and other polyhalogenated
carbons; Fibronection; Collagen; Hydroxyethyl methacrylates (HEMA);
Serum albumins; Suprafilm (Genzyme Corp.); Silicone polymer;
Polyurethanes; Tetrathane (Dupont); Polytetramethylene polymers;
Dacron; Polyester woven fabric; and Polycarbonated urethanes.
[0189] (d) Although the configuration of the memory-shaped linking
connector prior to thermal deformation (as exemplified by FIG. 34A)
may appear as a geometrically regular and coherent structure, there
is no requirement or demand that either the detailed structure or
overall appearance of any configured connector conform to these
parameters. Accordingly, it will be recognized and understood that
the deformable and deployable shape-memory alloy structure need not
take form as a completely encircling band or collar of
thermoelastic material. To the contrary, L-shaped, T-shaped or
H-shaped constructions of alloy material where the annular
sidewalls do not overlap or join completely and/or where a gapped
distance separates the arms of the linking connector are both
permitted and envisioned. Moreover, although the isotropic
cylindrical-shaped format of the connector illustrated by FIG. 34
is highly desirable in many instances, there is no requirement that
the diameter of the connector structure prior to or after thermal
deformation be constant or consistent over its entire axial length.
Thus, anisotropic structures as well as isotropic constructions are
intended and desirable. In this manner, the linking connector in
its initial state prior to thermal deformation may have a variable
internal diameter over the axial length of the article in which one
open end may be either greater or lesser in size than the other
open end; and there may be multiple increases and decreases in
diameter size successively over the entire axial length of the
connector itself. All of these variations in construction and
structure are within the scope of the present invention.
[0190] To illustrate some of the more common variations and
differences available and envisioned for a deformable in-situ and
deployable at will linking connector intended for use with the
present invention, the alternative embodiments illustrated by FIGS.
35-37 are provided. As shown within FIGS. 35A and 35B, the initial
shaped configuration for the thermoelastic structure 330 appears as
a cylindrical-shaped article or cuff having two open ends 332, 334
and a rounded sidewall 336. The body of the sidewall 336 is an open
meshwork of closed wire loops 338, each closed wire loop being
joined at multiple points along its perimeter to at least one other
closed wire loop--thereby forming an open grid meshwork. A notable
feature of the connector construction within FIG. 35A is the outer
edges of the open ends 332, 334, each of which is formed by a
closed wire loop which is more easily bent and thermally deformed
in-situ than the closed-loop meshwork in the middle of the sidewall
336. In many instances, the availability of closed-loop edges 340,
342 provide an enormous benefit and advantage when thermal
deformation of the linking connector occurs in-situ. In addition,
the first portion of the article shown by FIG. 35A has been
memory-shaped to deform substantially at the midline along the axis
BB' such that the upper sidewall upper portion 339 near the open
end 332 and the edge 340 will deform in-situ and flair outwardly as
a consequence of placing the sidewall in a temperature environment
greater than about 25-35.degree. C.
[0191] The result of thermal deformation in-situ at a temperature
greater than about 25-35.degree. C. and deployment of the
deformation in full is shown by FIG. 35B. The sidewall upper
portion 339 has become deformed and bent from the open end 332 to
about the midline axis BB'. However, the lower sidewall retainer
portion 337 has remained substantially unaltered overall its
surface area from the midline axis BB' to the other open end 334.
The full deployment of this memory-shaped second configuration is
illustrated by FIG. 35B and represents the thermally deformed
structure which attaches and secures a tubular conduit to the
internal lumen of an artery or vein in-vivo or into the internal
cavity of a hollow organ.
[0192] A third embodiment of a thermally deformable linking
connector is illustrated by FIGS. 36A and 36B. As shown therein,
the initial configuration for the deformable linking connector 360
is illustrated by FIG. 36A and appears primarily as a series of
coiled wires 368 whose overlapping and intersecting junctures have
been fused together to make a coiled unitary article. The
deformable article has two open ends 362, 364 and an open coiled
sidewall 336 formed from the commonly fused coils of wire. The open
lattice work of coiled wires 368 provides the flexible and
resilient meshwork suitable for achieving the primary functions of
the memory-shaped linking connector. The sidewall 366 also has been
pre-stressed along the middle axis CC' such that the uppermost
sidewall portion 369 will become bent and deformed outwardly when
exposed to an environment temperature greater than about
25-35.degree. C.
[0193] The consequence of placing the coiled linking connector in
an ambient temperature greater than about 25-35.degree. C. is shown
by FIG. 36B. It will be appreciated that the memory-shaped
configuration of FIG. 36B is intended to be an in-situ generated
event and result, which can be deployed fully and completely at
will. Thus, when fully deformed and deployed, the flared out upper
sidewall portion 369 has become bent at nearly a 90 degree angle
with respect to the lower retained sidewall portion 367; and the
midline CC' will generally serve as the axis of thermal deformation
and deployed curvature for the coiled linking connector.
[0194] A fourth alternative embodiment is provided by FIGS. 37A and
37B in which a thermally deformable cuff or band-shaped linking
connector 380 is shown having two open ends 382 and 384. In this
instance, however, the sidewall 386 of the linking connector is
comprised of a solid sheet of alloy material. Two other features
are also included in this embodiment of the thermally deformable
structure due to its construction using a solid sheet of resilient
material as the sidewall 386 for the linking connector. The
sidewall 386 has been preferably pre-scored to form cross-hatched
squares over the axial length of the sidewall; and the pre-scored
sidewall thus will deform far more easily and bend outwardly along
the scored lines of demarcation as shown when the linking connector
is placed in an ambient temperature greater than 25-35.degree. C.
Similarly, the sidewall material has been pre-stressed along the
midline axis DD' such that the upper most region 389 nearest the
opening 382 will become bent far more easily and deform in a
controlled fashion when and as required by the user.
[0195] The effect and consequences of placing the linking connector
380 in an ambient environment whose temperature is greater than
about 25-35.degree. C. is shown by FIG. 37B. The uppermost sidewall
portion 389 has thermally deformed into the memory-shaped second
configuration; and in the fully deployed state has become bent into
a curved lip extending outwardly from the midline axis DD'.
However, the lower sidewall portion 387 has remained substantially
unchanged from its initial shape and size. The memory-shaped
deformation characteristics have thus generated an in-situ
deformation and deployed configuration most suitable for the
attachment and securing of a tubular conduit in-vivo.
C. Superelastic Properties of the Linking Connector
[0196] It will be noted and appreciated also that the superelastic
properties and use characteristics of the linking connector as a
structural entity exist in addition to and concurrently with its
thermoelastic properties and the ability to thermoelastically
deform in-situ on-demand. The superelastic properties of each
linking connector in any of its many structural formats typically
include: (a) extreme elasticity in being able to return to its
original size and shape after having been stretched, compressed or
altered in configuration; (b) resilience in which the strain or
energy created by a bending movement, force, torque or shear force
and applied to an elastic material is converted and does not cause
fragmentation, or cracking, or a mechanical breakdown of the
material; and (c) malleability in being able to be mechanically
altered in shape or configuration (whether by rolling, forging,
extrusion, etc.) without rupture and without pronounced increase in
resistance to deformation. For purposes of practicing the present
invention, all of the conventional nickel-titanium metallic
formulations which are shape-memory alloys as described herein and
characterized by Table 1 previously also are alloys which have and
present superelastic properties.
[0197] The value of employing linking connectors which exhibit
superelastic properties in addition to their demonstrable
thermoelastic capabilities lies in the user's ability to control
separately and individually the physical deployment of the linking
connector in its intended memory-shaped configuration--in terms of
choosing the precise timing, physical location, and exact
placement--after thermoelastic deformation and shape-memory
reconfiguration of the linking connector structure itself has been
initiated. Thus, the act of and means for controlled
deployment--the spreading or arranging in appropriate position--for
the linking connector is separate and distinct from the thermal
initiation and event of thermoelastic deformation on-demand for the
linking connector in-situ. The differences are easily illustrated
by easy reference to the introducer assemblies shown by FIGS. 8B
and 29 and to the method of introducing a prepared communication
channel to a blood vessel or hollow organ as illustrated by FIGS.
9-14 and 30-33 respectively.
[0198] It is the user's choice and option, whether by personal
intent or necessity, when to allow the linking connector (then
joined to the tubular conduit) to reach the critical temperature
required for thermal deformation to occur. However, once this
critical temperature is reached, thermal deformation and thermally
caused alteration of the linking connector transient structure into
its permanent memory-shaped configuration will occur--if and only
if there is then sufficient physical space and ambient environment
room for the act of structural deformation to be performed fully
and completely. Yet, if the linking connector (and the joined
tubular conduit) lie within a constrained and limited space and/or
a close boundary environment at the moment of thermoelastic
initiation, then the thermally initiated act of deformation and
reconfiguration becomes restrained, incomplete, repressed, and
unfulfilled. No physical deployment and actual structural
alteration into the shape-memory configuration can or will occur
unless and until the physical constraint(s) are removed and the
linking connector is released and has sufficient spatial freedom of
movement and rotation to complete the act of shape deformation in
full and to present the intended shape-memory configuration in an
unconfined form.
[0199] Accordingly, if for example the critical temperature were
reached for the linking connector 82 as shown in FIG. 29, the
initiation and event of thermoelastic deformation will have
occurred and begun in-situ while the linking connector was
spatially confined within the internal volume of the sheath 250;
and the first sidewall portion 84 of the linking connector would be
physically constrained and be prevented from deforming in full by
the limited space and physical obstruction created by the interim
diameter size of the volumetric sheath 250. Similarly, as seen in
FIG. 3D, the first sidewall portion 84 remains restrained and
confined by being positioned within the recessed furrow 267 of the
perforating headpiece 230 such constraint and physical confinement
is removed and the linking connector released from the constrained
setting for an at-will controlled deployment and proper positioning
by the acts shown in FIG. 31.
[0200] It is essential therefore to recognize and appreciate that
while thermoelastic deformation in-situ for the linking connector
occurred on-demand--that is, within the volumetric sheath of the
introducer assembly, the act of physically deploying the
thermoelastically activated linking connector was purposefully
delayed and the act of thermal deformation itself was restrained
and controlled spatially until the moment the user chose for most
effective anatomic placement and appropriate local positioning for
the memory-shaped configuration. Clearly, it is the superelastic
properties of the alloy formulations which provide the user with
the capability not only to separate the individual act of
thermoelastic deformation in-situ on-demand from the act of spatial
deployment and constrained control at will of the spatial
deployment of the thermoelastically deforming linking connector;
but also to allow the user to choose for himself the precise
timing, physical location, and proper placement for the deployment
of a thermoelastically deforming linking connector as a direct
consequence and result of being able to control such spatial
deployment.
D. The Tubular Conduit
[0201] The tubular conduit comprises any biocompatible tube,
sleeve, channel, flow line, hose, piping, duct, or configured
outlet which allows and provides an unobstructed conveyance and
transport of fluid matter through its interior space. By
definition, the term "fluid matter" includes and encompasses any
and all flowing solids, liquids, and/or gases as well as any
mixture of these materials without regard to their chemical
composition, degree of purity, amassed volume or quantity, and/or
medical significance or value.
[0202] The tubular conduit has at least one tubular wall of fixed
axial length; has at least one proximal end for entry; has at least
one distal end for egress; and has at least one internal lumen of a
volume sufficient to allow for on-demand passage therethrough of
any fluid matter.
[0203] Many different types and constructions of tubular conduits
are conventionally known and used; and a wide range and variety of
tubular conduits are available which are extremely diverse in
shape, design, and specific features. All of the essential
requirements of a tubular conduit exist as conventional knowledge
and information; and all of the information regarding conduit
design and described in summary form hereinafter is publicly known,
widely disseminated, and has been published in a variety of texts.
The reader is therefore presumed to be both familiar with and have
an in-depth knowledge and a general understanding of conventional
tubular conduits.
[0204] A number of specific types of tubular conduits are known
today; but for purposes of practicing the present invention, a
number of newly designed or specifically designed conduits of
varying lengths and sizes suitable for use are expected and
intended to be developed and manufactured subsequently. Equally
important, minor modifications of the presently existing general
categories of tubular conduits are equally appropriate and are
expected to be found suitable for use when practicing the present
invention.
[0205] Merely representative of tubular conduits in general without
regard to their specific past usages or intended applications, are
those illustrated by FIGS. 38-47 respectively. As exemplified by
FIG. 38, a tubular conduit 550 is seen having a tubular wall 552 of
fixed axial length; having two proximal open ends 554 and 556 which
together generate the egress and exit to the interior of the
conduit, a single internal lumen 558.
[0206] Another variation commonly known is illustrated by FIG. 39
which shows a conduit 560 having a central tubular wall portion 572
of fixed axial length; having two or more branches 574, 576
respectively which collectively form the proximal ends 596, 594 for
entry into the internal volume of the conduit; and a single
unbranched end 580. It will be appreciated and understood that
FIGS. 38-47 are presented merely to show the overall general
construction and relationship of parts present in each flexible
tubular conduit suitable for use with the present methodology.
[0207] Also, in accordance with established principles of
conventional construction, the axial length of the conduit may be
composed of one or several layers in combination. In most
multilayered constructions, one hollow tube is stretched over
another to form a bond; and the components of the individual layers
determine the overall characteristics for the conduit as a unitary
construction. Some multilayered conduit structures comprise an
inner tube of teflon, over which is another layer of nylon, woven
Dacron, stainless steel or nitonol braiding. A tube of polyethylene
or polyurethane is then heated and extruded over the two inner
layers to form a bond as the third external layer. Other
constructions may consist of a polyurethane inner core, covered by
a layer of stainless steel or nitinol braiding, and a third
external jacket layer formed of polyurethane.
[0208] Several examples of basic conduit construction and design
are illustrated by FIGS. 40-47 respectively. FIGS. 40A and 40B are
perspective and cross-sectional views of a single tubular wall
considered the standard minimum construction for a conduit. FIGS.
41A and 41B are perspective and cross-sectional views of a
thin-walled design for a single layer extruded conduit. In
comparison, FIGS. 42A and 42B are perspective and cross-sectional
views of a standard multilayered construction having a braided
stainless steel midlayer in its structure. Finally, FIGS. 43A and
43B are perspective and cross-sectional views of a thin-walled
design for a multilayered conduit with a braided stainless steel
middle layer.
[0209] In addition, a number of different dual-lumen conduits are
known today. These differ in size and spatial relationship between
their individual lumens. The construction difference are
illustrated by FIGS. 44-47 respectively which show different
dual-lumen constructions for four tubular conduits having similar
or identical overall diameter size.
[0210] As shown therein, FIG. 44 shows a dual-lumen conduit 630
wherein a first external tubular wall 632 provides an outer lumen
volume 634 into which a second internal tubular wall 636 has been
co-axially positioned to provide an inner lumen volume 638.
Clearly, the construction of conduit 630 is a co-axial design of
multiple tubular walls spaced apart and co-axially spaced but
separate internal lumens of differing individual volumes.
[0211] In comparison, FIG. 45 shows a second kind of construction
and design by dual-lumen conduit 640 having a single external
tubular wall 642; and an centrally disposed inner septum 644 which
divides the interior tubular space into two approximately equally
lumen volumes 646 and 648 respectively. Thus, in this construction,
the diameter, length, and volume of internal lumen 646 is
effectively identical to the diameter, length and volume of
internal lumen 640; and both of these exist and are contained
within a single, commonly-shared, tubular wall.
[0212] A third kind of construction is illustrated by FIG. 46 and
shows an alternative kind of construction and design. As seen in
FIG. 46, the dual-lumen conduit 656 has a single external tubular
wall 652; and contains an asymmetrically positioned internal
divider 650 which divides the interior tubular space into two
unequal and different lumen volumes 650 and 658 respectively. Thus,
in this alternative construction, the discrete volume of internal
lumen 650 is markedly smaller than the volume of the adjacently
positioned internal lumen 658; and yet both of these internal
lumens 650 and 658 exist in, are adjacently positioned, and are
both contained within a commonly-shared single tubular wall.
[0213] A fourth construction and design for a dual-lumen conduit is
presented by FIG. 47 which shows a conduit 660 having a single
external tubular wall 662 of relatively large size and thickness.
Within the material substance 668 of the tubular wall 660 are two
discrete bore holes 664 and 666 of differing diameters which serve
as two internal lumens of unequal volume. Internal lumen 664 is
clearly the smaller while internal lumen 666 is far greater in
spatial volume. Yet each internal lumen volume 664 and 666 is
adjacent to the other, lies in parallel, and follows the other over
the axial length of the conduit.
[0214] In general, the tubular body conduit is flexible over most
of its length and may have one or more bends or curves towards the
ends. Conventional practice also permits using a number of
differently formed ends or tips which vary in design and
appearance. Accordingly, for purposes of practicing the present
invention, any construction of the tubular conduit whether having
one or more curves, or none; and whether or not there is more than
one designed portal for exiting or entering the lumen or multiple
lumens are all considered conventional variations in construction
design. Any and all of these designs and constructions are
therefore deemed to be encompassed completely and to lie within the
general scope of construction suitable for use with the present
invention.
1. Vascular Conduit Bypass Graft Material
[0215] Two major sources of conduits suitable for use as a vascular
bypass graft are presently known and available. These are:
synthetic prosthetic channel sections and previously excised blood
vessel segments.
[0216] The choice of graft conduit is crucial to the success of
coronary artery bypass grafting surgery (CABG) because the patency
of a coronary conduit is closely associated with an uneventful
postoperative course and a better long-term patient survival. The
standard vascular conduits used for CABG are excised blood vessel
segments taken from the greater saphenous vein (GSA) or another leg
or arm vein. An excellent substitute conduit for coronary bypass
operations that can be available on demand is certainly the desire
of every practicing cardiac surgeon. However, virtually every
synthetic alternative to arterial conduits or autologous fresh
saphenous vein conduits has proved disappointing. Fortunately,
patients with absolutely no autologous conduit are uncommon.
Circumstances exist, however, that often necessitate the use of
alternative synthetic conduits such as young hyperlipemic patients;
as absent or unsuitable autologous internal mammary artery and
greater saphenous vein as a result of previous myocardial
revascularization, peripheral arterial reconstruction; and varicose
vein ligation procedures. In the present era of increasing numbers
of repeat coronary revascularizations, approximately 15% of
patients requiring CABG are now in need of alternative synthetic
conduits.
a. Synthetic Conduits
[0217] The desired characteristics of synthetic conduits used as
bypass grafts are nonimmunogenicity, easy availability and storage,
less risk of kinking (due to its stiffness), a less turbulent flow
(due to uniform diameter), and an absence of branches.
[0218] The medical value of synthetic conduits as bypass grafts
in-vivo has been substantially investigated. See for example:
Foster et. al., Circulation 79 (Sup 1): 134-139 (1989); and Canver,
C. C., Chest 108: 1150-1155 (1995); and the other references cited
below. A summary review of the recent reports evaluating these
conduits thus is in order.
[0219] Historically, Sauvage and associates in 1976 [J. Thorac.
Cardiovasc. Surg. 72; 418-421 (1976)] described the placement of a
4.0-cm long, 3.5-mm diameter knitted Dacron flamentous vascular
prosthesis as an interposition graft between the aorta and right
coronary artery during repair of a vascular aneurysm of the
ascending aorta in an adult. The graft was demonstrated to be
patent by angiography 16 months after operation. A literature
search at the time found only two other prior reports of successful
aortocoronary grafting with synthetic conduits, both involving
children with congenital coronary defects. Two factors present in
all three cases that were suggested as promoting long-term patency
were that only short segments of prosthetic graft were placed, and
that they were implanted as interposition grafts from the end of
the coronary artery to the aorta.
[0220] The initial results of CABG with expanded
polytetrafluoroethylene (PTFE) (Gore-Tex. W. L. Gore and
Associates, Elkton, Md.) grafts were encouraging; however, this
impression was based on single-case reports or series with small
numbers of patients. Molins and co-authors in 1978 [J. Thorac.
Cardiovasc. Surg. 75: 769-771 (1978)] presented a patient in whom
they had constructed a bypass to the distal right coronary artery
with a 4.0 mm diameter PTFE graft, found patent on catheterization
3 months after surgery. Also, Yokoyama and associates in 1978 [J.
Thorac. Cardiovasc. Surg. 76: 552-555 (1978)] described five
aortocoronary bypass patients in whom 3.0-5.0-mm PTFE grafts had
been used. Four of five of these grafts were open on restudy 3-6
months postoperatively. Subsequently, Islam and colleagues in 1981
[Ann. Thorac. Surg. 31: 569-573 (1981)] reported that a 6-mm
diameter PTFE graft used for aorta-to-right coronary artery bypass
remained widely patent on repeat angiography 18 months after
surgery.
[0221] An indication of the early and midterm results of CABG with
PTFE grafts was provided in the 1981 report of Sapsford and
associates [J. Thorac. Cardiovasc. Surg. 81: 860-864 (1981)].
Twenty-seven coronary bypasses were constructed in 16 patients with
4.0-mm PTFE grafts. Eleven patients were restudied at 3 months
after surgery, and a 61% (11 of 18) graft patency rate was found,
in six patients who had repeat angiography 12-29 months after CABG,
six of nine PTFE grafts were open. Then, Murta and co-authors in
1985 [Ann. Thorac. Surg. 39: 86-87 (1985)] detailed a single case
experience where two 4.0-mm diameter PTFE aortocoronary grafts
remained present 53 months postoperatively. More recently, Chard
and associates reported in 1987 [J. Thorac. Cardiovasc. Surg. 94:
132-134 (1987)] long-term patency results with PTFE aortocoronary
grafts. Using both end-to-side and multiple, sequential,
side-to-side anastomoses, they constructed a total of 28 distal
coronary grafts in eight patients. Patency rates on repeat
angiography were 64% (18 of 28) at 1 year, 32% (9 of 28) at 2
years, 21% (6 of 28) at 3 years, and 14% (4 of 28) at 45
months.
[0222] The choices of materials recognized as being suitable for
the making of a biocompatible synthetic conduit are quite limited.
These are provided by Table 3 below.
b. The Excised Blood Vessel Segment
[0223] A variety of blood vessel segments excised from the vascular
system in-vivo are suitable for use as bypass graft conduits. A
representative, but incomplete, listing is provided by Table 4
below.
3TABLE 3 Synthetic Conduit Materials Synthetic Substances Dacron
(knitted or woven) polymer; Polytetrafluoroethylene or "PTFE"
(knitted or woven); Impra; Teflon polymer; Kevlar polymer;
Polycarbonated urethan; Silicone; Thermoplastic polymers and
elastomers; and Collagen, human or bovine.
[0224]
4TABLE 4 Vascular Conduits For Bypass Grafting Venous Conduits (a).
Autologous vein conduits. Greater saphenous vein segments; Lesser
saphenous vein segments; Upper extremity (cephalic and basilic)
vein segments. (b). Nonautologous vein conducts. Umbilical vein
segments; Greater saphenous vein homografts. Arterial Conduits (a).
Autologous arterial conduits. Internal mammary artery segments;
Right gastroepiploic artery segments; Inferior epigastric artery
segments; Radial artery segments; Splenic artery segments;
Gastroduodenal artery segments; Left gastric artery segments;
Intercostal artery segments. (b). Nonautologous arterial conduits.
Bovine internal thoracic artery segments.
[0225] The preferred sources of blood vessels suitable for use as a
vascular bypass graft are the saphenous veins. These veins
constitute the superficial veins of the lower extremities and
comprise both the greater (or long) saphenous and the lesser (or
short) saphenous veins. Anatomically, the long saphenous vein
begins on the medial side of the foot and ends in the fermoral vein
below the inguinal ligaments; and the short saphenous vein begins
behind the lateral malleous and runs up the back of the leg to end
in the popliteal vein. However, if the saphenous veins of the
particular patient are unsuitable or unavailable for any reason,
either the cephalic or the basilic veins are very acceptable
substitutes for use as a vascular bypass conduit. However, if these
leg or arm veins are not available, synthetic or other biologic
materials may also be used as substitutes.
[0226] The medical procedure to isolate and excise the saphenous
vein of choice is conventionally known and considered a routine
surgical technique. The saphenous vein is harvested under general
anesthesia. An incision is first made in the medial malleolus,
where the saphenous vein is often dilated. The saphenous vein is
identified and then dissected with a single incision made along its
course with scissors. Branches are doubly clamped with hemostatic
clips and divided. The saphenous vein is then freed up and removed
from the leg. The leg wound is closed with subcutaneous sutures and
Steristrip adhesive over the incision. The vascular segment is
prepared on a separate sterile table with adequate light and
loupes, and branches are selectively ligated with 4-0 silk. An
oval-tip needle on a syringe is inserted into the graft to gently
dilate it by administering a balanced electrolyte solution (pH 7.4,
chilled to 7.degree. to 10.degree. C.) and 10,000 units/liter of
heparin. A valvulotome is inserted into the vein graft segment and
the valves clipped with a 3-mm right-angle stainless steel
instrument with a highly polished ball tip on the right angle. The
knife edge is protected and sharply splits the cusp, causing
valvular incompetence. Measurements for the approximate lengths of
the grafts may be made with umbilical tapes, and the appropriate
lengths may be chosen before it is sewn to the cuff and coronary
arteries.
2. Tubular Conduits Suitable for Use as Access Ducts
[0227] In the main, many of the same tubular conduits formulated
and composed of synthetic materials may be used as access ducts
when joined to a hollow organ. Accordingly, these same materials
previously listed within Table 4 herein as synthetic conduit
materials are most suitable and desirable for use as access duct
conduits.
[0228] In addition, in order to improve the performance of the
access duct conduit when joined and secured into the internal
spatial volume a hollow organ in-situ, it is most desirable to
provide the exterior surface of the access duct with a hydrophilic
coating or to mold the entirety of the exterior surface at least
using a hydrophilic plastic composition. By providing the access
duct with appropriate hydrophilic properties, the tubular conduit
will have a lower coefficient of friction and will more easily
slide through the aperture to be made in the body cavity wall.
[0229] These highly desirable hydrophilic coatings or plastics are
substantially non-reactive with respect to living tissue and are
non-thrombogenic when placed in contact with blood or other body
fluids. Appropriate hydrophilic coatings therefore would include
polyvinylpyrrolidone--polyurethane or polyvinylbutyrol
interpolymers as described in U.S. Pat. Nos. 4,100,309 and
4,119,094. In addition, appropriate molding compounds which could
alternatively be applied as coatings, include hydrophilic polymer
blends with thermoplastic polyurethane or polyvinylbutyrol and
hydrophilic polyvinylpyrrolindone or other poly(N-vinyl lactans) as
described in U.S. Pat. Nos. 4,642,267 and 4,847,324. Such
hydrophilic coatings will typically reduce the coefficient of
friction by over sixty percent for metals and can reduce the
coefficience of friction for plastics by over ninety percent.
[0230] The present invention is not to be restricted in form nor
limited in scope except by the claims appended hereto.
* * * * *