Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR ELECTROSURGICALLY OBTAINING
ACCESS TO THE BILIARY TREE AND PLACING A STENT THEREIN
BACKGROUND
1. Field of the Invention
The present invention is directed to catheters
adapted for passage through the accessory channel of an
endoscope into a duct or passageway within the
gastrointestinal system of the body. Although not limited
in its applicability and scope, the invention has particular
applicability to procedures which involve the advancement of
the catheter to positions within the biliary tract and
especially to the practice of Endoscopic Retrograde
Cholangiopancreatography.
2. Description of the Prior Art
A number of procedures have evolved in recent
years using instruments intended to be inserted through an
endoscope in various positions within the gastrointestinal
system for the purpose of diagnosis and for therapeutic
procedures, including the insertion of stem s, devices for
the extraction of stones from the biliary duct, the removal
of polyps and the extraction of tissue for biopsy purposes.
One diagnostic technique which has come into use
is Endoscopic Retrograde Cholangiopancreatography (ERCP)
which is described in copending application Serial
No. 07/880,842, filed May 11, 1992. The FRCP technique is
an endoscopic technique which involves the placement of a
side-viewing instrument within the descending duodenum. The
procedure eliminates the need
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for invasive surgical procedures for identifying biliary
stones and other obstructions of the biliary and
pancreatic ducts. As background of the invention, the
ERCP technique exemplified the problems and difficulties ,
which the present invention addresses.
Utilizing this technique, the-Papilla of Vater
and common biliary duct are cannulated, contrast medium
injected and pancreatic ducts and the- hepatobiliary tree
visualized radiographically or examined with a duodeno
fiberscope. Skilled medical practitioners can visualize
approximately 90-950 of the biliary and pancreatic ducts
using this technique.
ERCP is-typically performed on an X-ray table.
During the procedure, the patient's oropharynx is
anesthetized with topical lidocaine, and the patient is
sedated intravenously with diazepam. Atropine and
glucagon are given intravenously to relax the duodenal
muscles.
The FRCP procedure has heretofore- typically
been performed by the endoscopic introduction of a
single lumen catheter into the pancreatic and common
biliary ducts of a patient. Such ERCP catheters have
typically been constructed from Teflon. At times, a
spring wire guide may be placed in the lumen of the
- catheter to assist in cannulation of the ducts. A
stylet, used to stiffen the catheter, must first be
removed prior to spring wire' guide insertion. The
introduction of the spring wire guide eliminates the
ability to injec-t contrast -medium or makes it highly
cumbersome. -
To summarize the procedure, an ERCP catheter is
initially inserted through the endoscope and into the
biliary or pancreatic ducts. If difficulty is '
encountered or i-f the operator so desires, a spring wire
guide is threaded into the catheter to assist in the
cannulation. After the catheter is inserted into the
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duct and threaded over the spring wire guide, the spring
wire guide is removed. A radio-opaque contrast medium
is then injected through the single lumen of the
catheter in order to identify obstructions such as bile
stones. Once located and identified, such stones can
then be eliminated or destroyed by methods such as
mechanical lithotripsy utilizing a device such as an
Olympus BML-10/20 Mechanical Lithotriptor.
This method of performing ERCP has several
disadvantages. Most notably, the process of withdrawing
the stylet or spring wire guide in order to clear the
single lumen for contrast medium or dye infusion
frequently repositions the catheter. Thus, when the
radio-opaque or contrast medium is injected into the
catheter, the catheter is often improperly positioned
for proper fluoroscopy or X-ray visualization.
Moreover, this method presents the further problem of
having to repeatedly remove the stylet or an
approximately six foot long spring wire guide, maintain
its cleanliness and then reinsert it into the catheter.
In addition, the dye is sticky and reintroduction of the
guide wire is made -difficult due to the frictional
resistance offered by it. Finally, single lumen
catheters frequently experience the problem of back-flow
in which the radio-opaque dye is squirted back out the
side port of the catheter and onto the administering
medical professional.
The above problems often result in the need to
repeat the procedure and a time consuming exercise of
trial and error. Multiple attempts at properly
positioning the catheter and spring wire guide are often
necessary. Increased amounts of tracer dye associated
with multiple injections increase the risk of
pancreatitis. Because the ERCP procedure is performed
under sedation, the additional time required for proper
catheter positioning tends to increase the risk to the
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patient. Furthermore, because ofthe-- considerable
expense of maintaining a procedure room,-- the use of
single lumen FRCP catheters can add considerably to the
expense of the procedure. Accordingly, practice of FRCP
procedures has heretofore been limited to only the most
skilled endoscopists.
SUMMARY OF THE INVENTION __
The invention has particular applicability in
the performing of ERCP procedures, other diagnostic and
surgical procedures performed within the biliary system,
as well as other parts of the gastrointestinal system in
general, by the,-- use in such procedures of catheters
having at least two lumens, and preferably three or four
lumens. The mufti-lumen catheter assemblies of the
invention are specially designed to be inserted into a
duct or body passage through the accessory channel of an
endoscopic instrument. A catheter assembly for use in
carrying out the invention comprises, in its broadest
aspects, a catheter body of substantially cylindrical
shape and substantially uniform diameter having a
plurality of independent lumens extending lengthwise
thereof . At least two lumens exit at the distal tip of
the catheter body with each exit port facing generally
distally along -the passage being explored axially and
forwardly. The catheters of the present invention are
sized to be passed through the accessory port of a
conventional endoscopic instrument. The catheters have
a combined length sufficient to extend the length of the
standard accessory channel and into the more remote
portions of the-- duct or passage and further have a
proximal section extending proximally of the endoscope '
channel for asufficient distance to allow for
manipulation of .the catheter by the user into the most '
extreme position. In the exemplary case of the biliary
system, the invention allows for substantially complete
exploration and visualization without the need to remove
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the spring wire guide. Follow-up procedures, such as
stmt placement, tissue sampling, use of a papillotome/
sphincteratome or the like are accomplished through a
lumen of the catheter already placed and may be
accompanied by periodic dye injection and visualization
without removal of the catheter. For- certain of these
procedures, the wire guide is preferably left in place,
as will be noted in the explanation which follows. A
further advantageous embodiment of the invention
involves a multi-lumen catheter with a reduced diameter
distal tip portion on which a dilatation balloon is
secured. In a related embodiment, a reduced diameter
distal end portion serves as a platform for a stmt.
Alternatively, a stmt may be advanced over a catheter
after performing the ERCP procedure by severing the ERCP
catheter with a catheter cutter and then advancing the
stmt over the FRCP catheter with a second catheter.
Yet another embodiment employs a needle-knife assembly
which may be used in an ERCP procedure to facilitate
easier access to the common-bile duct.
The use of multi-lumen catheters for procedures
such as described above offers many advantages over the
prior art- practice of using single-lumen catheters. As
noted above, one important advantage is the facility for
injection of contrast medium so as to attain complete
visualization of a system of passages, such as the
biliary tract, without the need to remove the spring
wire guide. When one recognizes that a catheter for use
in ERCP procedures must be approximately 200 cm in
length and the spring wire guide must be an additional
200 cm or so in length, the very act of removal of the
spring wire guide to allow for injection of contrast
medium through a single-lumen catheter can be seen to be
both awkward and time consuming: Since the spring wide
guide is needed again for repositioning the catheter,
its extreme length and resilient nature makes it very
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difficult to avoid loss of sterility when it is
temporari-ly removed from the catheter. Furthermore, when
the spring wire guide is reinserted after injection of
the contrast medium through the single lumen, it has ,
been found that hecause the contrast medium tends to be
sticky, the resistance offered within the lumen impedes
reintroduction. This condition is aggravated due to the
relatively small diameter and the length of the lumen
through which the spring wire guide must be passed.
Since the catheters can be properly placed much more
easily with less trial and error,- the provision of
separate lumens for dye injection and guide wire
placement has been found to dramatically reduce the use
of tracer dye. In addition, the provision of a separate
lumen for guide wire placement eliminates the risk that
air will enter the biliary tract as may occur when a
single lumen is used for dye and guide wire. Still
further, it is highly desirable to have further lumens
within the catheter to allow for -other procedures-,- such
as the introduction and removal of stems, the use of
instruments, such as papillotomes, biopsy cutters, stone
extractors, forc-eps, knives and the like. Accordingly,
it is an important objective of the invention, to provide
a multi-lumen catheter of small enough diameter to pass
through the accessory channel of -,the endoscopic
instrument having the following characteristics: to
provide for additional lumens sized to permit the
aforementioned procedures within the limited
cross-section available; to .retain the requisite
flexibility so as to facilitate passage to a final
position within an extended tortuous passageway; and to
maintain the patency of the lumens without bunching up
or kinking as the catheter is advanced over the spring
wire guide and into a final position.
One aspect of the invention is the provision of
a catheter constructed from a blend of resins producing
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a catheter body having peak stress of at least 8000 psi
s and a torqueability of at least .3 inch ounce at body
temperature, wherein torqueability is measured as
resistance to twisting through 360° with one end of the
catheter fixed. An important feature of the present
invention involves the treatment of at least the distal
end section of the catheter with a hydrophilic coating.
The hydrophilic coating of the present invention
provides a highly lubricated surface which is activated
l0 by the presence of moisture. In the case of a biliary
catheter, the biliary fluids activate the coating as it
enters the biliary passage of the patient. The
hydrophilic coating serves the further function of
softening the catheter body so as to increase its
suppleness and kink resistance and lubricity. Further,
the softened distal portion is less traumatic to the
tissue within the body passage. In a preferred
embodiment, the lubricous hydrophilic coating is
confined to that portion of the catheter liable to be
inserted within the endoscope and the body passage.
This facilitates initial passage of the catheter to the
desired- position within the passageway, since the
catheter remains in a firmer state until itcontacts the
body fluid. Since the coating is quite slippery, its
absence from the proximal end of the catheter allows the
medical professional to retain a firm grip on the
catheter as it is manipulated to the desired position.
The lubricous hydrophilic coating may optionally also be
applied- within the spring wire. guide lumen and other
lumens provided for the insertion of instruments.
Preferably, catheters formed according to the
invention are extruded, utilizing a blend of polymers
comprised of nylon, especially nylon 11, and an ester
linked polyether-polyamide copolymer (PEBA). In the
case of biliary catheters, catheters having two or more
lumens, one of which is of sufficient--diameter to allow
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passage of a guide wireand to allow passage of another
device and the other for a dye or other injectable fluid
and having an external diameter of between about 1.8 mm
and about 3.8 mm can be formed by an extrusion process. ,
These catheters, when coated with the lubricous
hydrophilic coatings of the type herein referred, are
extremely supple and offer a kink resistance not
obtainable with -prior art catheters formed of Teflon.
When formed from the resin blends of the present
invention, the catheter material does not exhibit the
tendency to bunch up on the wire guide as the catheter
is pushed through the passageway. The catheters have
good "torqueability", that is to say, the tip follows
the proximal end without undue twisting when the medical
professional rotates the catheter duringplacement.
Preferably, the catheter has a central section
substantially equivalent in length tothe length of the
accessory channel of a standard video duodenoscope, a
distal section substantially equal in length to the
portion of the -body passage to be negotiated and a
proximal section of-a length sufficient to--allow for
manual manipulation when the distal section is- in an
extreme position within the body passage. At least the
distal section but not the proximal section is coated
with a hydrophilic coating which provides. lubricity
within the passage. _ __,
By providing exit ports in the distal tip of
the catheter and orienting the ports in a generally
axial direction, so that devices or injectable fluids
exit distally of- the catheter, procedures. which, involve
the advancement of the catheter over the spring wire '
guide, use of a papillotome or other instrument and
injection of contrast medium at successive locations '
along a relatively confined duct or passageway, such as
the biliary duct;- are facilitated. By use of at least
two lumens having ports facing generally forwardly in
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the direction of movement of the catheter, removal of
- the wire guide from the catheter during other procedures
can be avoided. Direct visualization devices and other
instruments can be passed through one lumen while the
spring wire guide remains in place in a second lumen for
ongoing repositioning of the catheter as is desired by
the user. Catheters according to the invention may be
provided with a dilatation balloon or a supporting
surface on the distal tip portion for support of a
stent. Desirably, additional lumens are reserved for
the injection of a tracer dye and aspiration of biliary
fluid.
The ERCP procedure described herein can be made
easier by using a pre-loaded needle-knife in a
dual-lumen catheter in accordance with the present
invention, to obtain easier access to the biliary tree.
Because the entrance to the biliarytree is guarded by
the sphincter muscle, it is often difficult for the
physician to place the catheter into the common bile
duct. Typically, an electrosurgical sphincteratome is
used in this application. Sometimes, it is not possible
to obtain access without exploratory surgery. The
incorporation of a needle- knife into a multi-lumen
catheter enables several diagnostic and therapeutic
procedures to be performed with only one cannulation of
the bile duct. In the preferred embodiment, the
needle-knife is disposed in an elongated sheath which is
removably installed in one lumen of a dual lumen
catheter. The physician can use the needle-knife to
incise tissue proximal to the papillary orifice and then
immediate canulate and visualize the common bile duct
with the catheter by introducing a contrast medium
through the other lumen of- the catheter. The
needle-knife sheath and internally disposed needle-knife
can be left in the catheter to function as a stiffening
element to assist in the cannulazion, or the sheath and
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needle-knife can be removed and a wire guide inserted in the
lumen. This procedure does not require the catheter to be
withdrawn from the patient and considerably reduces the time
and effort necessary when compared with the prior art
methods.
Another aspect of the invention relates to the use
of a catheter cutter to separate the catheter from a
catheter connector to facilitate placement of a stmt in the
biliary tree. After cannulating and visualizing the area
under study in a duct of the patient, the catheter is
severed from the catheter connector and a stmt is then
advanced over the catheter with a second catheter having at
least one lumen of a sufficient diameter. The catheter
cutter is generally comprised of a pair of members, each
having a pair of hingedly connected tines, which members are
clamped together about a pair of centrally disposed cutting
blades. The catheter cutter is positioned at a proximal end
of the catheter near the catheter connector and, in a manner
similar to a wire cutter, hand pressure is applied to the
tines of the catheter cutter to sever the catheter from the
catheter hub without severing the wire guide. This method
overcomes the more difficult and time consuming process of
first withdrawing the catheter over the wire guide and then
threading the stmt over the wire guide.
According to another aspect of the present
invention, there is provided a catheter for
electrosurgically obtaining access to the biliary tree of a
patient and visualizing a duct thereof, said apparatus
comprising: at least a first lumen and a second lumen
defined therethrough, each lumen terminating in an opening
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defined at a distal end of said catheter, a needle-knife
disposed in said first lumen, a deployment means connected
to said needle-knife at a proximal end of said catheter for
extending and retracting said needle-knife between a
deployment position and a sheathed position relative to said
distal end of said catheter, and said needle-knife
electrically communicating with a power source.
According to still another aspect of the present
invention, there is provided a catheter for
electrosurgically obtaining access to a duct of a patient,
said catheter comprising: at least a first lumen and a
second lumen defined therethrough, each lumen terminating in
an opening defined at a distal end of said catheter, an
elongated sheath threaded through said first lumen, a
needle-knife disposed in said sheath, a deployment means
connected to said needle-knife at a proximal end of said
sheath for extending and retracting said needle-knife
between a deployment position and a sheathed position
relative to a distal end of said sheath, and said needle-
knife electrically communicating with a power source.
According to yet another aspect of the present
invention, there is provided a catheter for
electrosurgically obtaining access to a bile duct of a
patient, said catheter comprising: at least a first lumen
and a second lumen defined therethrough, each lumen
terminating in an opening defined at a distal end of said
catheter, an elongated sheath threaded through said first
lumen, a needle-knife disposed in said sheath, a deployment
means connected to said needle-knife at a proximal end of
said sheath for extending and retracting said needle-knife
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between a deployment position and a sheathed position
relative to a distal end of said sheath, and said needle-
knife electrically communicating with a power source.
According to a further aspect of the present
invention, there is provided a catheter for placing a stmt
in a duct of a patient, said catheter comprising: a first
catheter having a proximal end and a distal end, said first
catheter having a catheter connector at said proximal end
thereof and at least a first lumen and a second lumen, said
first lumen having a wire guide threaded therethrough, a
second catheter having at least one lumen defined
therethrough for enabling said second catheter to be
threaded over said first catheter to advance said stmt over
said first catheter, and a catheter cutting means for
cutting said first catheter near said proximal end of said
first catheter to separate said catheter connector from
first said catheter.
According to yet a further aspect of the present
invention, there is provided a catheter for placing a
biliary stmt around a biliary calculus in a biliary duct of
a patient, said catheter comprising: a first catheter
having a proximal end and a distal end, said first catheter
having a catheter connector attached to said proximal end
thereof and at least a first lumen and a second lumen, said
first lumen having a wire guide threaded therethrough, a
second catheter having at least one lumen defined
therethrough for enabling said second catheter to be
threaded over said first catheter to advance said stmt over
said first catheter, and a catheter cutting means for
cutting said first catheter near said proximal end of said
first catheter to sever said catheter connector from said
first catheter.
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According to still a further aspect of the present
invention, there is provided a catheter for placing a stmt
around a pancreatic obstruction in a pancreatic duct of a
patient, said catheter comprising: a first catheter having
a proximal end and a distal end, said first catheter having
a catheter connector attached to said proximal end thereof
and at least a first lumen and a second lumen, said first
lumen having a wire guide threaded therethrough, a second
catheter having at least one lumen defined therethrough for
enabling said second catheter to be threaded over said first
catheter to advance said stmt over said first catheter, and
a catheter cutting means for cutting said first catheter
near said proximal end of said first catheter to sever said
catheter connector from said first catheter.
According to another aspect of the present
invention, there is provided a catheter for placing a stmt
around a cystic obstruction in a cystic duct of a patient,
said catheter comprising: a first catheter having a
proximal end and a distal end, said first catheter having a
catheter connector attached to said proximal end thereof and
at least a first lumen and a second lumen, said first lumen
having a wire guide threaded therethrough, a second catheter
having at least one lumen defined therethrough for enabling
said second catheter to be threaded over said first catheter
to advance said stmt over said first catheter, and a
catheter cutting means for cutting said first catheter near
said proximal end of said first catheter to sever said
catheter connector from said first catheter.
In accordance with the present invention, it is an
object thereof to provide multi-lumen catheters for use in
gastrointestinal and other procedures.
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It is a further object of the invention to provide
a method for performing cannulation and visualization of a
duct of a patient with a multi-lumen catheter having at
least one lumen for receiving a wire guide and another lumen
for injecting a contrast medium through the catheter and out
of an opening in the distal tip thereof.
It is another object of the invention to provide a
method of using a multi-lumen catheter as
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described above, having a needle-knife contained in a
- sheath disposed in a first lumen of the catheter for
incising tissue proximal to the entrance to a duct of a
. patient to obtain access to the duct, where the duct can
be cannulated and visualized by passing a contrast
medium through a second lumen of the catheter without
removing the sheath and needle-knife from the catheter.
It is still another object of the invention to
provide a method of using a mufti-lumen catheter having
a needle-knife contained in a sheath disposed in a first
lumen of the catheter for incising tissue proximal to
the entrance to a duct of a patient to obtain access to
the duct, where the sheath and needle-knife may be
removed from the first lumen ofthe catheter while
maintaining the catheter in position near the entrance
to the duct, and a wire guide then inserted in the first
lumen of the catheter to enable cannulation of the duct
and visualization of the duct by infusing a contrast
medium through a second lumen of-the catheter while the
wire guide remains in the first lumen of the catheter,
and, if necessary, adjustment of the position of the
distal tip of the catheter -by advancing the wire guide
along the duct and then advancing the catheter over the
wire guide to visualize the duct at a desired location.
It is a further object of the invention to
provide a catheter cutter for severing a first catheter
used in an ERCP procedure from a catheter connector to
enable threading of a stmt over the first catheter with
a second catheter to place the, stmt in a duct of a
patient without having to withdraw and remove the first
catheter over the wire guide.
In accordance with the above objects, the
present invention will now be described with specific
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an overall view of a dual-lumen
biliary catheter of the present invention;
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Figure 2 is a partially broken away, partial
section view on an enlarged scale as compared-to Figure
1 of a- dual-lumen biliary catheter of the present
invention;
Figure 3.is a side view, partly in section, of
a dual-lumen biliary catheter body formed according to
the present invention illustrating the distal tip
illustrating the contrast stripes at the distal end of
the catheter;
Figure 3A is a section view illustrating the
dual lumens of the biliary catheter of Figures 1-3 taken
along line 3A-3A of Figure 3;
Figure 3B is a fragmentary side view of a dual
lumen catheter having a balloon at the distal tip and
having the cross-sectional configuration of Figure 3A;
Figure 4 illustrates a biliary catheter of the
present invention through an endoscope accessory channel
at the point of introduction into the common biliary
duct; - - _ _.
Figure 5 is an enlarged detailed view of a
catheter of the present invention illustrating its exit
from the distal tip of- the accessory channel of the
endoscope -
Figure 6-is a side elevational view of an
alternative distal tip configuration for the biliary
catheter of the present invention;
Figure 7 illustrates the catheter and including
a wire guide feed apparatus utilized with the present
invention;
Figures 8 and 8A illustrate views- illustrating
the unlocked and locked position of a wire guide locking '
mechanism used with the invention;
Figures -9A and 9B are side and top views,
respectively, of a catheter of the -invention having a
beveled tip and digitized markings;
Figure 10 is an end view of the catheter of
Figures 9A and 9B;
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Figures 11 and 12 are side and end views of the
distal tip section of a triple-lumen polypectomy
catheter formed according to the invention;
> Figure 12A is a cross-sectional view of a
modified form of the polypectomy catheter illustrated in
Figures 11 and 12;
Figures 13A and 13B illustrate the distal and
proximal end sections, respectively, of a triple-lumen
dilatation balloon catheter formed according to the
invention;
Figure 14 is a detail view on an enlarged
scale, in section, of a portion of the catheter of
Figures 13A and 13B;
Figure 15 is a sectional view on an enlarged
scale taken on line 15-15 of Figure 13A;
Figure 16 is a sectional view on an enlarged
scale taken on line 16-16 of Figure 13A;
Figures 17A and 17B illustrate the distal and
proximal end sections of a mufti-lumen catheter for
placing a stmt;
Figure 18 is a sectional view enlarged with
respect to Figures 17A -and 17B illustrating the distal
portion of the catheter with the stmt in position;
Figure 19 is a cross-sectional view of a
four-lumen catheter used for the purposes of cannulating
the common bile duct and the pancreatic duct;
Figure 20 is a cross-sectional view of a
triple-lumen catheter in which a papillotome is
accorninodated for the purpose of tissue cutting as an
aid to catheter insertion;
Figure 21 illustrates a modified form of
dual-lumen catheter useful for stone removal;
' Figure 22 is a cross-sectional view of a
triple-lumen catheter used for stone visualization and
removal;
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Figure 23 is a cross-sectional view of an
alternative embodiment of a catheter used for the ,
purposes explained with respect to Figures 13A-16;
Figure 24 is a cross-sectional view of a
catheter used for stmt placement and removal;
Figure 25 is a side elevational view of a
catheter cutter in accordance with the present invention;
Figure 26 is a sectional view depicting the
catheter cutter assembly comprised of top and bottom
components and-centrally disposed cutting elements;
Figure 27 is an exploded sectional view
depicting the cutter top and bottom components and
cutting blades prior to assembly;
Figure 28 is a side elevational view of the
inside of the top cutter component;
Figure 29 is a side elevational view of the
inside of the bottom cutter component;
Figure 30 is a side elevational view of a
catheter and catheter connector of.the type shown in
FIG. 1;
Figure 31 is a side elevational view of the
catheter and catheter connector shown in FIG. 30 with
the catheter cutter disposed so as to sever a portion of
the catheter to remove the catheter connector from the
catheter;
Figure 32 is a side elevational- view of the
catheter being separated from the catheter connector;
Figure 33 is a side elevational view of a stmt
being threaded over the catheter. with a.guiding catheter
placed behind the stmt to advance- the stmt into
position;
Figure 34 is a top plan view of a needle-knife
assembly where- the needle-knife sheath, connecting tube
and needle-knife are disposed within a multi-lumen
catheter in accordance with the present invention and
the needle-knife is retracted in a sheathed position;
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Figure 35A is a top plan view thereof with the
needle-knife in a deployed position;
Figure 35B is a sectional detail view of the
distal end of the catheter, catheter sheath and
needle-knife in the deployed position; and
Figure 36 is a sectional view depicting details
of' the needle-knife actuator assembly, sheath and
connecting tube.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Preferred embodiments of the improved catheters
of the present invention are described with reference to
Figures 1-18, wherein unless otherwise indicated, the
same numbers are utilized to denote the same or
equivalent parts. For the purpose of description, the
present invention will be described in the context of
its use in the cannulation and visualizing of the common
biliary duct of a patient pursuant to an ERCP
procedure. It is to be recognized that the present
invention is applicable to all ERCP procedures involving
the cannulation and radiological visualization of the
common biliary, pancreatic, common hepatic and cystic
ducts and to related procedures, including those
involving cholecystectomy, papillotomy, polypectomy and
sphincteratomy, as well as biopsies, placement of stem s
and the use of cytology brushes.
Referring generally to Figures 1-3, a
dual-lumen biliary catheter 10, constructed in
accordance with the present invention, is illustrated.
In Figure l, showing a preferred embodiment of a
dual-lumen catheter, the catheter of the present
invention comprises a cannula or tubular catheter body
12 having a proximal end 12a for connection to a
branching- connector 14 and a distal end 12b for
insertion into the biliary duct of a patient. Tubular
body 12 has a substantially circular cross-sectional
shape and a uniform outer diameter. Two independent
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lumens extend lengthwise thereof and exit through
separate--ports at the distal tip. Preferably, the ,
catheter is provided with a tip having a relatively
sharp bevel, although unbevelled blunt tips and
sonically formed tips may sometimes be employed. For
reasons which will be understood from the following
explanation, the-- two lumen ports within the tip are
oriented so that they face forwardly and substantially
along the path of- advance of-the catheter.
Tubular-body 12, in a preferred embodiment of a
biliary catheter, has a length of approximately 200 cm.
This length is sufficient to allow the catheter 10 to be
inserted endotracheally into a patient via an endoscope
and to reach within the biliary and pancreatic ducts
located adjacent- the patient's duodenum via an attached
fiberscope during an ERCP procedure.
The proximal end 12a of catheter body 12
attaches to branching means 14 which couples the body 12
to wire guide feeding means 16-and contrast medium
infusion means 18. In a preferred embodiment as shown
in Figures 1, 2 and 4, branching means 14 comprises a
polymeric branching connector 15 which joins the wire
guide feeding means 16 and contrast medium infusion
means 18. The branching connector 15 may include a
connector -19 having an affixed apertured wing 20.
Referring to Figures 1 and 2,-the wire guide
feeding means 16, in a preferred embodiment, comprises a
port having an eighteen gauge luer lock hub 17 which is
affixed to the branching connector means 14. The wire
guide feeding means 16 is utilized to feed a wire guide
24 into and out of one lumen of the catheter 10. The
wire guide 24 may be threaded in one lumen of the
catheter l0 prior to introduction of the catheter and
wire guide into the endoscope. A wire guide utilized in
the embodiment of Figures 1-3A preferably has a diameter
of about .035 inches. The use of a wire guide having,
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this diameter permits the wire guide to be used for
placing an indwelling scent, to be discussed below.
The wire guide 24 may optionally be coated with
Teflon in order to add to its lubricity. The wire
guide of the present invention is preferably fed and
withdrawn with the assistance of an auxiliary apparatus,
such as the wire guide feed apparatus disclosed in U. S.
Serial No. 07/608,234 entitled "Hand weld Device For
Feeding A Spring Wire Guide", filed November 2, 1990,
and now U.S. Patent No. 5,125,906 assigned to Arrow
International Investment Corp., assignee of the present
invention. An overall view of such a device 27 is
illustrated in Figure 7. Device 27 includes an
elongated coiled conduit 27a within which the wire guide
24 resides when not in use and a feed device 27b which
allows for hand feed of the wire. As shown in Figures 7,
8 and 8A, the wire guide feed device 27 is preferably
affixed to the inlet hub of a wire clamping means, such
as snap lock adapter 29 for locking the position of the
wire. Snap lock adapter 29 basically comprises a knob
29a which cams a tubular portion 29b radially inwardly
to grip the wire guide upon relative movement of the
parts toward one another. Figures 8 and 8A illustrate
the respective unlocked and locked positions of the
adapter.
Referring to Figures 1 and 2, the contrast
medium infusion means 18, in a preferred embodiment,
preferably comprises a polymeric tube 26 which includes
a twenty-gauge connector 28 secured to tube 26 at one
end. The connector 28 has a threaded outer surface 30
onto which a cap or stopper (not shown) may be affixed.
The interior 28a of the connector 28 is typically luer
shaped and is designed to be ccupled to a syringe
containing radio-opaque contrast medium or dye. The
contrast medium or dye is injected down tube 26 and into
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a contrast medium lumen 34 of the catheter, as discussed
below. ,
Referring to Figures 2 and 3, the distal end
12b of the tube -12 is shown in detail. The distal end
of the catheter includes a bevelled tip portion 12b and
means 25 extending proximally of the tip portion for
rendering sections of contrasting the._outer distal
surface of catheter radio-opaque. Contrast means 25
facilitates the visual identification of the distal end
of catheter 10 by the endoscope. In a preferred
embodiment, means 25 comprises a plurality of non-toxic
ink stripes 25a, formed using an ink such as is sold
under the specification 2920 by Gem Gravure of West
Hanover, Massachusetts. It is to be appreciated that
contrast stripes 25a comprising other materials may be
utilized in the catheter of the present invention.
Moreover, it is to be appreciated by those skilled in
the art that the entire catheter 10, or portions
thereof, may be or applied with any acceptable contrast
medium. As shown in Figures 9A and 9B, the tip 12b of
the catheter may be calibrated as at 25a at
predetermined intervals, such as 5 mm.
As further illustrated in Figures 1-3, 9A and
9B, the preferred catheter tip 12b-_isbeveled to
facilitate ease of insertion and passage. A relatively
steep bevel has been found to be an optimal
configuration in that it is relatively easy and
non-traumatic to position the catheter -and affords
reasonable resistance to bending and buckling.
Referring to Figures 3 and 3A, the lumens 32,
34 of a preferred form of dual-lumen catheter 10 of the '
present invention are shown so as to_ detail their
cross-sectional shape. The catheter 10 includes wire '
guide lumen means_32 and contrast medium lumen means
34. The lumen means 32, 34 extend the entire length of
the catheter body, along parallel paths between the
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proximal end 12a and distal end 12b. Referring to
Figures-9A, 9B and 10, distal end 12b is shown bevelled
with the contrast medium lumen means 34 terminating just
distally of the wire guide lumen means 32. In all
embodiments, lumens 32 and 34 exit through ports in the
distal tip which are oriented so that they face
generally lengthwise or axially of the catheter. As
illustrated in Figures 9A and 10, the contrast lumen
port 34 is located in the perpendicular portion of the
l0 tip, whereas the major portion of the wire guide lumen
port is in the beveled position. In biliary catheters,
it is preferred that the port for lumen 32 be within
about one-quarter inch of the distal tip. Preferably,
the dye lumen is at the tip so as to eliminate
interference with dye flow by the side walls of a narrow
passageway and/or by the guide wire.
As best shown in Figures 3A and 10 , wire guide
lumen means 32 is circular in cross-section and has a
diameter of about .05 mm to allow passage of a .035 mm
wire guide, a stmt or other device of similar size.
The top of wire guide lumen 32 is defined by an arcuate
septum 32a which defines the interior sidewall of the
contrast medium lumen 34. In a preferred dual-lumen
embodiment, contrast medium lumen 34 is crescent
shaped. While certain preferred embodiments of the
present invention are described in the context of -a
biliary catheter having dual lumens, the present
invention such catheters having more than two lumens.
Further, while the present invention is described with
respect to a contrast medium lumen 34 having a crescent
shape as a means of maximizing lumen size within a
relatively small diameter catheter body, certain of -the
objectives of the invention may be achieved when the
contrast medium lumen assumes one of a plurality of
other geometric shapes.
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Catheters of the present invention may be
constructed from extrudible polymers. Preferable
proportions are about 18-22 wt. obarium sulfate, about
40 wt. % to about 60 wt o nylon 11 and about 20 wt. % to
about 4 0 wt . o PEBA . A blend o f 6 0 wt . o nylon 11, 2 0
wt. o PEBA and 20 wt. o barium sulfate is especially
preferred. Nylon 11 sold under the trademark BESVOA and
PEBA sold under the trademark Pebax are available from
Elf Atochem, Philadelphia, Pennsylvania. The barium
sulphate allows for easy visualization and- catheter
location under fluoroscopy and has been observed to
increase stiffness. This blend is readily extruded into
multi-lumen catheters having an o.d. ranging from 3.8 mm
down to about 1.8 mm. Catheters formed from this blend
have the requisite balance of torqueability, resistance
to bunching and stretching and good flexibility.
A further important feature of the present
invention is the addition of a hydrophilic coating on
the outer surface of the catheter 10 and optionally
within the wire guide lumen 32. The hydrophilic
coating, when -applied to the catheter, imparts
suppleness and kink resistance to the catheter. The
hydrophilic coating _ furtherapparently reduces the
hardness of the polyurethane or nylon. The hydrophilic
coating of the preferred embodiment comprises Methylene
Chloride (MeCl), Polyethylene Oxide (PEO) and Tyrite
7617 Adhesive.
The hydrophilic coating is preferably applied
to the catheter pursuant to the following process.
Initially, 1400 ml of MeCll is poured into a container
which is placed on stirrer plate. A stirring magnet is
then dropped into the beaker, and the stirring plate is
activated. Stirring is adjusted until a vortex forms.
Next, 14.91 g. ~ .02 g. of PEO are slowly added tothe
stirring solution. The solution is stirred continuously
for about 10 minutes in order to break up any lumps of
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PEO. Using a syringe, about 15.75 ml Tyrite 7617
adhesive is added to the stirring solution which is
stirred for an additional five minutes. The stirred
- solution is then poured into a treatment tank.
The catheter 10, with its end sealed off, is
then dipped into the tank until the portion to be coated
is immersed. The catheter 10 is left in the tank for
about 1 second, quickly retrieved and the excess
solution allowed to drip into the tank. The catheter is
then air dried for about 8 hours.
The catheter 10 with hydrophilic coating
provides a highly lubricated surface which is activated
by the biliary fluids of the patient. The hydrophilic
coating may also be activated by the gastric fluids
which enter the endoscope. The hydrophilic coating
reduces the durometer of =the catheter and imparts kink
resistance and suppleness to the catheter. The coating
has been found to yield a lower coefficient of friction
than that of comparable Teflon catheters. While the
present invention is being described in the context of a
preferred hydrophilic coating, it is to be appreciated
that other hydrophilic coatings may be utilized in the
present invention. Examples of such hydrophilic
coatings are found and described in U.S. Patent No.
4,943,460 entitled "Process for Coating Polymer Surfaces
and Coated Products Produced Using
Such Process." Another hydrophilic coating is Hydromer
"Slippery When Wet" coating manufactured by Hydromer,
Inc. of Whitehouse, New Jersey. Preferably, the
slippery coating is not applied to the proximal end
section of the catheter so as to facilitate manual
manipulation thereof during catheter placement.
The operation and use of the biliary catheter
10 as so far described is now explained with reference
to the Figures. Initially, the patient is sedated or,
in rare situations, placed under- general anesthesia.
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Using the wire guide advancer 27 of the type shown in
FIG. 7, the wire guide 24 is inserted through an ,
endoscope and exits through the .side of an attached
fiberscope 36, the end of which is shown in Figure 5 is
situated in the patient's duodenum 38 as shown in FIG.
4. The catheter10 is then threaded over the spring
wire guide 24 via spring wire guide lumen 32 or the
catheter 10 having the wire guide 24 threaded
therethrough is fed through the accessory channel 36 and
both the catheter and wire guide are advanced into the
common bile duct 40.
Next, as shown in FIG. 1, a pre-filled syringe
of radio-opaque dye or contrast medium is attached to a
connector 28. A sufficient amount of dye to fill the
catheter is then injected into tube 26. A clamp or
adhesive tape may be used to lock the relative positions
of the catheter and wire guide. An example of a clamp
which achieves the function is a clamp of the Series 340
clamps marketed by Halkey Medical of St. Petersburg,
Florida. Contrast medium is then injected into the
contrast medium lumen 34 as shown in FIG. 3A which exits
at distal end 12b and into the common biliary duct 40,
thereby permitting X-ray orfluoroscopic visualization
of the duct 40. Markings 25a facilitate - precise
adjustment of the catheter. If.the position of the
catheter needs to be adjusted, the wire guide 24 is
advanced and the catheter 10 advanced accordingly. The
catheter can be rapidly adjusted and contrast medium or
dye can be repeatedly infused without the need for
repeated
insertion and removal of the wire guide 24. '
The present invention thus provides for probing
with the wire guide 24 via lumen 32 and the injection of '
contrast medium or dye via contrast medium lumen 34, and
further probing and further injection of dye until a
proper catheter.-- position is achieved. The present
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invention eliminates the time consuming step of removing
. the wire guide 24 prior to each change in catheter
position and contrast medium infusion. The use of the
- catheter of the present invention can save over 20
minutes of time during a typical ERCP procedure. In
addition, a laser fiber for biliary lithotripsy can be
placed through one lumen with ongoing injection of
contrast medium or fluid in the second lumen. Further,
selective cannulation of the right and left hepatic
ducts, cystic ducts or pancreas becomes more directed,
safe and efficient.
A particular feature of the present invention
is its adaptability for use in placing a stmt around a
biliary calculus 42 or cystic or pancreatic
obstruction. In approximately 50 of all FRCP
cannulations, surgery is mandated. However, surgery is
often not always possible at the time of the FRCP
procedure. In such situations,- a stmt is typically
placed within the common biliary or pancreatic duct
around the calculus.
As used in one procedure for stmt placement,
the catheter 10 is utilized in association with-a wire
guide 24-having a length greater than twice the length
of the catheter 10, or over 400 cm in length. The wire
guide may be threaded with the catheter into the
endoscope, as described above. The wire guide utilized
in this embodiment should preferably have a diameter of
about .035 inches. The stmt is tubular with a
longitudinally extending slit which permits it to be
fitted over the wire guide.
The wire guide is advanced to a desired
position within the common biliary duct and the catheter
then advanced relative to the wire into a final
position. Contrast medium or dye is infused, and the
calculus 42 is located, as shown in Figure 6. The
catheter 10 is then removed from the endoscope.
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Because the wire guide 24 has a length greater
than twice that of the catheter 10 , the catheter 10 can ,
be completely removed from the endoscope over the wire
guide 24 without the need for withdrawing the wire
guide . After the catheter 10 is removed, a stmt may be
placed forward of the catheter over the wire guide. The
catheter is utilized to push the stmt into the
endoscope, over the wire guide, into the common biliary
duct and around the biliary calculus 42. When the stmt
is in position, the wire guide 24 is then removed along
with the catheter.
Referring now to FIGS. 25-33, there is depicted
an illustrative embodiment of a catheter cutter 100 for
severing a catheter 12 from a connector 14 of the type
described above and illustrated in detail in FIG. 1, 9A,
9B and 10 to enable a second catheter 106 to be threaded
over catheter 12 to advance a stmt 108 into a desired
position in a duct of -a patient.
As illustrated in FIGS. 25-27 and 29, catheter
cutter 100 is comprised of a top half 110a and a bottom
half 110b which retain a pair of-cutting blades 112 as
described in more detail below. Top half 110a includes
a pair of tines 114a which are hingedly connected at
area 116a to enable them to flex inwardly towards one
another upon the application of hand pressure. The
tines 114a each define a semi-circular inner bore 118a
bounded by projections 120a which engage corresponding
shelves 121a to- limit inward flex. At the outer end
122a of top half110a, the semi-circular inner bore 118a
of each tine communicates with a second larger
semi-circular bore 124a from which a plurality of '
projections 126a project radially inwards -to engage the
flanged hub portion 19 of the connector hub 14 as '
illustrated in FIGS . 26 and 31 . At the inner end 128a,
a pair of outer bosses 130 and- inner bosses 132 project
for engaging the cutting blades 112 as described below.
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To facilitate assembly, a plurality of guideways 138 are
. defined inwardly from inner end 128a to facilitate
assembly as shown in FIG. 26 and described below.
The bottom half 110b is of similar construction
to top half 110a, and is principally comprised of a pair
of tines 114b which are hingedly connected at area
116b. The tines 114a each define a semi-circular inner
bore 118b bounded by projections 120b which engage
corresponding shelves 121b. At the outer end 122b of
bottom half 110b, the semi-circular inner bore 118b of
each tine communicates with a second larger
semi-circular bore 124b from which a plurality of
projections 126b .project radially inwards as described
above. At the inner end 128a, a pair of recesses 134
are formed, in which cutting blades 112 are disposed.
The cutting blades 112 are fabricated from stainless
steel and are preferably about .006 inches thick. The
cutting blades are held in place by pressure between the
top half 110a and the bottom half 110b when the
components shown in the exploded view of FIG. 27 are
assembled as depicted in FIG. 26. In order to
facilitate assembly, the bottom half 110b includes a
plurality of flexible fingers 136 which are received in
guideways 138 of top half 110a in locking relation (FIG.
26).
Referring now to FIGS. 30-33, the catheter
cutter 100 may be used to sever a catheter 12 from a
connector 14 to enable a stmt 108 to be advanced over
catheter 12 without having to remove the catheter 12.
The use of this procedure for stmt placement as
described above with respect to placing a stmt around
the biliary calculus, cystic obstruction or pancreatic
obstruction, obviates the requirement for a wire guide
having a length greater than twice the length of the
catheter and the need to subsequently unthread the
catheter over the wire guide 24. After performing.
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cannulation and visualization of the duct in accordance
with the procedure described above, the method entails ,
the steps of placing the catheter cutter 12 over the
flanged hub portion 19 of the connector- 14 near the
proximal end 12a of the catheter -12, applying hand
pressure to the tines 114a and 114b until the catheter
12 is severed from the connector 14, stripping the
connector 14 from the catheter 12, and then placing a
stent 108 over the outer surface of the catheter and
advancing the stmt with a second catheter 106.
A catheter, as shown in Figures 3 and 3A,
having a balloon adjacent its distal tip, as shown in
Figure 3B, may be used with a wire guide (not shown)
having an iridium charge placed in its distal tip so as
to dispose iridium for treatment in the biliary tract.
In this treatment application, the wire employed is
preferably .035 inches in thickness and is passed
through a nasalpassage using an endoscope. After the
wire guide is positioned within the biliary tract, the
endoscope is removed and the catheter -is advanced over
the wire guide using lumen 32 as the wire guide lumen
adapted to be passed through round lumen 32 having a
diameter of :040 inches. Lumen 34 serves as the
inflation lumen and exits in a radial port for inflation
of the balloon. The overall diameter of the catheter is
2.8 mm. Once the iridium, which may be fitted into the
tip of the catheter at 35, is properly placed, the
balloon is inflated through lumen 34 to maintain both
catheter and iridium in place. Although the catheter
may be deployed orally as in other procedures due to the
length of the iridium treatment, the catheter is
preferably inserted through a nasal passage.
Catheters having the cross-section of Figure 3 '
are also useful for tissue sampling with a brush. In
this application,- lumen32- preferably has--a diameter of
about .040 inches. Lumen 34 is utilized for a saline
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solution for the purpose of cleansing the tissue to be
- sampled prior to obtaining the sample with the brush. A
triple-lumen catheter used in the practice of
polypectomy is disclosed in Figures 11 and 12. The
catheter illustrated in Figures 11 and 12 has a first
lumen 48 dimensioned to pass a polypectomy snare, a
second lumen 49 through which an injection medium will
be passed and a retrieval lumen 50 for passage of a
basket or other retrieval device. Lumen 49 or lumen 50
may be used to pass a flexible plastic or stainless
steel needle for injecting a polyp once it is visualized
to further assist the physician in excising the polyp
with a snare. As indicated in Figure 11, where a snare
is illustrated projecting from the lumen port 48, the
snare is a device which uses radio frequency energy to
cauterize the root of the polyp and the energy so used
exits through a plate in which the patient is seated.
Once the polyp is incised, a net, basket or other
retrieval device of known construction is passed through
lumen 49 for grasping and retrieval of the polyp through
the lumen. If a large polyp is to be removed, the
catheter. itself is removed at this point. The catheter
of Figures 11 and 12 has an external diameter of 2.5
mm. The snare lumen has a diameter of .5 mm, whereas
the lumens 49 and 50 have diameters of =4 mm. Lumen 48
exits through the bevelled portion of the distal tip,
whereas lumens 49 and 50 exit through the portion
disposed perpendicular to the long axis of the catheter.
For certainpurposes, the dual-lumen catheter
configuration of Figure 12A may be satisfactory for the
practice of polypectomy. As utilized, the catheter
configuration of Figure 12A is provided with a lumen 48a
of about .050 inches in diameter for passage of the
snare and a lumen 49a of about .040 inches in diameter
for-the injection needle device. Retrieval is effected
by withdrawal of the catheter with the embodiment of
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Figure 12A. The catheter illustrated in Figure 12A
preferably has an outside diameterof about 2.8 mm.
Still another embodiment of the invention, as
illustrated in Figures 13A-16, is a triple-lumen
catheter having a dilatation balloon 52 which may be
used, for example, to facilitate removal of gall stones
by the dilation of a restricted portion of the biliary
tract. The catheter of Figures 13A-16 has a main body
portion 53 of a first uniform outer diameter and a
distal tip portion 54 of a smaller uniform outer
diameter. Preferably, the distal tip has a bevelled
configuration similar to the tip of the embodiment of
Figures 1-3.
The catheter of Figures 13A-16 has a first
lumen 55 which extends lengthwise thereof from a
connector 56 to an exit port at the distal tip in the
manner illustrated in Figure 10. Lumen 55 is preferably
sized .to permit _the passage of a .035- inch guide wire.
A second crescent shaped lumen 57, as illustrated in
Figures 15 and 16, also exits in a port at the distal
tip and provides for the injection of tracer dye. The
catheter is also provided with a third lumen 58 which
exits in a shoulder 59 separating the larger diameter
main body portion 53 from the smaller diameter tip
portion 54. Lumen 58 is provided for the delivery of an
inflation medium for inflating the balloon 52. The
inflation medium employed is desirably anincompressible
fluffd and is typically a saline solution. The fluid may
include a tracer dye to permit visualization of the
balloon by fluoroscopy. The catheter of Figures 13A-16
has a maximum diameter of 2.8 mm to allow for passage '
through the accessory channel of an eridoscope and a
diameter.of approximately 1.8 mm in the distal tip
portion. The use of a smaller diameter distal tip
portion facilitates passage into more remote portions of
the biliary tract and also provides room for packing the
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uninflated balloon so that it does not project
appreciably beyond the surface of the large diameter
catheter body portion. Another catheter configuration
for use with a dilation balloon 52 is shown in FIG. 23
and described below.
In use, the catheter of Figures 13A-16 is
advanced utilizing the wire guide, as described above,
until the desired position is reached, utilizing a
tracer dye and fluoroscopy to assist-in the guidance of
the catheter to the desired location. Balloon 52 is
inflated when the event a stricture in the biliary duct
is encountered. Once the duct is dilated, stones
encountered may, in many cases, dislodge and begin to
remove themselves naturally, but if need be, a stmt may
be inserted to maintain patency of the duct to encourage
the passage of the stone or the guide wire may be
removed and an extractor device may be employed
utilizing lumen 55.
Figures 17A-18 illustrate a catheter having
utility for the placement of a stmt in the biliary
tract. The catheter of Figures 17A-18 is similar in
structure to the- catheter of Figures 13A-16 in that it
has a main body portion 60 of a first diameter and a
distal tip portion 61 of a second similar diameter on
which a stmt 62 is supported. In the illustrative
embodiment, the distal portion 61 has an outer diameter
of 1.8 mm which is suitable for supporting a 10 French
tubular stent formed of a biologically inert material,
such as polyurethane . As seen in Figure 18 , when stmt
62 is placed on the distal tip portion, its proximal end
- surface bears against a shoulder formed between the
larger diameter body portion 60 and the reduced diameter
distal end portion 61. In the illustrative embodiment,
main body portion 60 has an outer diameter of 2.8 mm for
passage through a 3.2 mm endoscope accessory channel.
The outer diameter of stmt 62 is approximately 3 mm.
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The catheter of Figures 17A-18 is provided-with two
independent and continuous lumens 55 and 57 preferably
having the configurations of the lumens in Figure 16.
Lumen 55 is dimensioned to accept a .035 wire guide
which exits at the distal tip. The crescent shaped
lumen 57 provides for the injection of tracer dye for
use in visualization of the passage and location of the
stricture where the stmt is intended- to be placed. In
use, the catheteris advanced over the wire guide using
the tracer dye to assist in placing it. When the
stricture is located and the~stent properly positioned,
the catheter and wire guide are withdrawn leaving the
stmt in place . As is known in the art, stmt 62 is
provided with barbs 63 which hold the steiZt in position
as the catheter-.is withdrawn. The barbs are yieldable
upon application of a predetermined force by a retrieval
device when it is desired to remove the stmt. An
advantage of the embodiment of Figures 17A-18 is that
the relatively small diameter distal portion relatively
easily negotiates restricted portions of the duct. The
procedure is facilitated by maintaining the wire guide
within the catheter to impart stiffness to the catheter
and resistance to kinking.
Catheters having three or more lumens, as
illustrated in Figures 11-16, allow for the performance
of other procedures in conjunction with ERCP or the use
of a lighting device while allowing the wire guide to
remain in place. Triple-lumen catheters having outside
diameters rangingfrom 3.8 mm down to about 1.8 mm may
be extruded utilizing the resin blends described above
with three lumens having inside diameters of .5 mm with -
a minimal wall thickness of .005 inches. One such lumen
will accommodate- a .018 mm wire guide, while the second
lumen is reserved for infusion of contrast medium, and a
third such lumen is reserved for additional instruments,
such as a papillotome or sphincteratome, a snare, a
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basket and other accessories, such as forceps, stone
- extractor, biopsy cutters or direct visualization
lighting devices. Additionally, a lumen may be provided
which exits radially at a location spaced adjacent the
distal tip for inflation of a dilation balloon used for
dilating the tract for removing bile stones or a
previously introduced stmt. Catheters formed in
accordance with the invention are useful for the
endos,copic examination and treatment of other parts of
the gastrointestinal system as well. Multi-lumen
catheters can be provided with outer diameters of 3.8,
2.8 and 1.8 mm which allow for use with standard
endoscopes having channels with internal diameters of
4.2, 3.2 and 2.2 mm, respectively.
- An important advantage of a catheter having
three or more lumens is that the wire guide may be
maintained within its lumen while performing a procedure
involving advancement of a device, such as a cytology
brush, papillotome or an optical visualizer, allowing a
third lumen to be reserved for the injection of dye.
The presence of the wire guide serves to prevent kinking
and collapse of all lumens, thus allowing for unimpeded
advancement of the device employed, dye injection and/or
aspiration of bile for laboratory analysis through a
lumen not contaminated with dye. The wire guide also
facilitates switching from one device to another. When
using an optical device, a fourth lumen may be
advantageously reserved for injection of saline solution
to clear the area being visualized prior to use of the
device.
Further specific embodiments and procedures of
use for -mufti-lumen catheters formed according to the
invention are described with particular reference to the
cross-sectional views of Figures 19-24.
Figure 19 is a cross-section of a mufti-lumen
catheter utilized for disposing two .035 inch wire
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guides simultaneously, one within the pancreatic duct
and one throughthe cystic duct through lumens 70 and
71, utilizing contrast medium injected through lumens 72
and 73. Once the wire guides are in place, the catheter
of Figure 19 is withdrawn and individual catheters -
advanced over -- the selected guide wire for
catheterization of either the pancreatic or cystic
duct . The catheter of Figure 19 preferably has an outer
diameter of about 2.8 mm. The catheter of Figure 19 is
of advantage when an uncertainty exists as to the extent
and location of patient stress.
Figure 20 illustrates a cross-section of a
catheter with which a papillotome is used for tissue
cutting as an aidfor catheter insertion. In use of the
catheterof Figure 20, circular lumen 74 is reserved for
a papillotome which is preferably permanently mounted in
the lumen. Placement of the catheter of Figure 20
involves use -of additional lumen 75 for a wire guide and
additional lumen 76 for contrast medium in the manner
described above.- with respect to Figures 1-12. The
catheter of Figure 20 preferably has an outside diameter
of about 2.8 mm.
Figure 21 is a cross-section of a catheter
useful in procedures for stone removal. Lumen 78
(upper) is used for the passage alternatively of a guide
wire or a fiber optic device for visualization of
stones. Lumen 79 is reserved for passage of a stone
basket. Alternatively, the catheter of Figure 21 may be
equipped with a--dilatation balloon adjacent its distal
tip which is- inflated with an incompressible medium.
After placementof the distal tip, the balloon is '
inflated to dilate the duct to effect dislodgment of the
stone. A catheter so constructed will have an outside '
diameter of approximately 2.8 mm. At the option of the
physician, the guide wire may be removed and replaced
with the optical device for visualization of the stone
removed by the basket or by dislodgment with the balloon. -
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An alternative use of a catheter having the
. configuration of Figure 21 includes use of a vacuum
assist for stone removal by application of a vacuum to
one of the lumens while reserving the other either for a
stone retrieval basket or as the inflation lumen for the
balloon. To maximize lumen size in this application,
the catheter preferably has an outside diameter of about
3.8 mm.
The cross-sectional view of Figure 22 depicts
an alternative form of catheter used for visualization
and removal of gall stones. As illustrated in Figure
22, lumens 82, 83 are used for injection ofcontrast
medium and for a guide wire respectively. Lumen 84 is
reserved for a basket for the removal of stones. Once
the catheter is within the biliary tract, the wire guide
is removed from lumen 83 and replaced with a fiber optic
visualization device to confirm that the stone, not a
air bubble, is present. The basket is then manipulated
through lumen 84 to retrieve the stone. The catheter of
Figure 22has an outside diameter of about 2.8 mm.
Figure 23 is an end view of triple-lumer_
catheter having an alternative configuration to the one
illustrated in Figure 15, for use with the dilation
balloon 52 in which the inflation lumen, shown at 86, is
an annular lumen. The annular inflation lumen 86
facilitates more rapid inflation and deflation of the
balloon 52 because of the greater volume of air which
may be passed therethrough as compared to the catheter
configuration depicted in FIG.. 15. The catheter is
provided with a circular lumen 87 for a .035 inch wire
guide and a crescent-shaped lumen 88 for injection of
contrast medium. The catheter of Figure 23 pref-erably
has a 2.8 mm outside diameter and is in other respects
substantially the same as the embodiment illustrated in
Figures 13A-16.
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Figure 24 illustrates an end view of a modified
version of the catheter of Figures 17 and 18. According ,
to Figure 24, the catheter depicted has a wire guide
lumen 90, a retrieval lumen 92 for a basket or snare and r
a dye lumen 94, all extending through the reduced
diameter distal tip portion. Except for.. the inflation
lumens, the lumens in Figures 19-24 extend continuously
and independently and exit through axially facing
ports. The catheter of Figure 24 has a maximum outside
diameter of about 3.8 mm. The reduced diameter distal
portion has a diameter of about 2.8 mm which allows for
support of a 7 French stmt 95 having its circumference
flush with the circumference of the remainder of the
catheter. Once the stmt is visualized, the snare is
utilized to grasp its proximal end. The stmt is
withdrawn by withdrawing the snare and, if necessary,
the catheter until the stent is within the large
intestine where it may be released. Thereafter, the
guide wire is -used to locate the tip of the catheter at
the desired location with the biliary or cystic duct.
The catheter is withdrawn with the stent remaining in
place and the catheter then removed further until it is
within the intestine. The snare or basket is then used
to pick up the old stmt and the -endoscope and catheter
are then withdrawn from the
body.
Referring now to FIGS. 34-36, there is depicted
a needle-knife assembly 200 adapted for use with the
multi-lumen catheter-_12 shown in FIGS. 1, 9A, 9B and
10. The needle-knife assembly 200 is principally
comprised of . _a- deployment mechanism 202, and an '
elongated sheath 204 having an elongated connecting tube -
205 and needle-knife 206 disposed therein. '
The deployment mechanism 202 includes a body
208 having a pair of rails 210 which define a centrally
disposed slot 212. Body 208 includes a-first end 214 in.
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which a thumb ring 216 is disposed, and a second end 218
. at which a fitting 220 is located for receiving the
sheath 204 and connecting tube 205 as described below.
A sliding member 222 is slidably connected to the body
208. The sliding member 222 includes a pair of opposed
finger rings 224 which enable a user to grasp the same
with the forefinger and index finger. By placing a
thumb through thumb ring 216, the sliding member 222 may
be advanced towards the second 218 of the body 208 to
deploy the needle-knife 206, and retracted towards the
first end 214 and against stops 221 towithdraw the
needle-knife 206 into the sheath 204 as described
below. The sliding member 222 has an internally
disposed brass insert 224 which electrically
communicates with a brass binding post 226 for making an
electrical connection to a power source (not shown) to
provide a cutting/coagulating current as is well known
in the art. The binding post 226 is situated within a
connector cap 228 integral with sliding member222.
As shown in FIG. 35, the elongated connecting
tube 205 is attached to and electrically communicates
with the insert 224. The connecting tube 205 is
fabricated from stainless steel and extends through the
fitting 220 in the second end 218 of the mechanism body
208 and terminates in a distal end 230. The connecting
tube 205 has a hollow bore (not shown) into which the
needle-knife 206 is partially disposed near distal end
230. The connecting tube 205 is then crimped over the
needle-knife 206 at location 234 as shown in FIG. 36.
The fitting 220 tightly receives the elongated tubular
sheath 204 and provides strain relief therefor. In a
preferred embodiment, the sheath 204 is made from
' polyimide material with a Tefloncoating. This enables
fabrication of a sheath 204 with an outer diameter as
small as approximately .035 inches, to enable advancing
the same through one lumen of the dual lumen catheter 12.
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used in an ERCP procedure in accordance with the present
invention. The use of polyimide material provides good
kink resistance, even if the sheath is fabricated with a
very thin wall thickness, and the Teflon coating
provides a -smooth surface to enable the sheath 204 to be
easily inserted and removed from the catheter 12. FIG.
35B shows the orientation of the connecting tube 204
disposed within -the catheter 12, where the distal end
232 of the sheath 204 extends a nominal distance from
the distal end 12b of the catheter 12.
In the preferred embodiment, the needle-knife
206 has a diameter of approximately .006 inches, and is
fabricated from a "memory" metal alloy such as Nitonil.
As is known in the art, memory metals undergo a
crystalline phase change and thermoelastically deform
when heated and cooled. These crystal phase changes
between what are known as high temperature Austenite and
low temperature Martensite, enable a component made from
such material to contract when heated, and to return to
its original configuration when cooled. Moreover, the
stress-strain behavior of a memory metal alloy makes the
material much easier to deform when cooled (Martensite)
than when at an elevated temperature (Austenite). In
the present invention, the use of this material is
advantageous since the needle-knife 206 is very thin and
susceptible to deformation during the cutting
procedure. The__memory material helps it return to its -
original orientation if deformed by stress during the
cutting procedure. When the needle-knife 204 is heated
by applying -the cutting/coagulating current, the
crystalline transformation to Austenite makes it much
more difficult to deform. If a sufficient force is then
applied to the needle-knife 206 during the procedure,
the material can strain to relieve the applied stress as
it transforms back to Martensite, and once the stress is
reduced, it will unstrain and revert back to Austenite.
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Finally, after the applied current is removed, the
resulting cooling of the needle-knife material and
associated crystal phase change to Martensite makes it
more flexible.
Referring now to FIGS. 34, 35A and 35B, the
needle-knife 206 is disposed so as to remain in a
sheathed position within sheath 204 with respect to the
distal end 232 thereof. The sheath 204 is inserted
through lumen 32 of catheter 12 so that the distal end
232 of the sheath protrudes slightly beyond the distal
end 12b of the catheter 12. The catheter assembly (of
the type shown in FIG. 1) is attached to the deployment
mechanism 202 by threading the luer lock hub 17 of the
connector 14 into the insert 220 at the second end 218
of the deployment mechanism 202.
Preferably, the needle-knife assembly 200 is
pre-loaded in the catheter 12. This facilitates the use
of the needle-knife assembly in a typical FRCP procedure
using a multi-lumen catheter. In this method, the
physician advances the catheter 12through an endoscope
(as shown in FIG. 4) and into the patient's duodenum
proximal to the entrance to the common bile duct 40,
typically into or just above the papillary orifice. By
grasping the deployment mechanism 202 by finger rings
224 and thumb ring 216, the physician then advances the
sliding member 222 towards the second end 218 of the
deployment mechanism 202 to cause the needle-knife 206
to extend from the distal end of the sheath 204 as shown
in FIGS. 35A and 35B. The. physician applies an
appropriate amount of cutting/ coagulating current to
the needle-knife 206 through the binding post 226, and
manipulates the needle-knife by using the elevator
and/or positioning controls of the endoscope to incise
tissue. Typically, a 3-5 millimeter across by 2-4
millimeter deep incision into the papilla is
sufficient. The needle-knife 206 is then retracted into
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the distal end 232 of the sheath 204 by moving the
sliding member 222 rearwardly towards the first- end-214
and against the stops 221 of the deployment mechanism
202. This enables the physician to insert the catheter ,
12 into the common bile duct with less effort. Once
access is gained to the common bile duct, the physician
can then cannulate and visualize the same in accordance
with the ERCP procedure described in the foregoing. The
sheath 204 and needle-knife 206 can be left within the
first lumen 32 of the catheter 12 to function as a
stiffening element to enable advancing the catheter into
the common bile duct 40 (see FIG. 4) , or the sheath 204
and needle-knife 206 may be withdrawn from the catheter
12, and a wire guide 24 then inserted in its place by
simply unthreading the luer lock hub 17 from deployment
mechanism 202 and attaching a wire guide feeding
apparatus 27 as shown in FIG. 7 and described above.
The common bile duct 40 can then be visualized by
infusing a contrast medium through lumen- 34. To
facilitate further cannulation and/or visualization of
the common bile or other ducts, the wire guide 24 may be
advanced along -the duct and the catheter 12 then
repositioned by advancing the-catheter 12- over the wire
guide to the appropriate location, and the -infusion
procedure may be repeated.
This method saves a considerable amount of time
over prior art procedures where cutting instruments had
to be.removed prior to infusing the contrast medium. By
keeping the needle-knife assembly 200 in place, the
physician can perform several diagnostic and therapeutic
procedures with only one cannulation ofthe common bile
duct.
The present invention has been described with
reference to the attached Figures and described
embodiments. It is to be appreciated that other
embodiments may fulfill the spirit and scope of the
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present invention and that the true nature and scope of
the present invention is to be determined with reference
to the claims appended hereto.
10
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25
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