U.S. patent application number 13/466276 was filed with the patent office on 2012-11-08 for catheter assembly including internal bolster.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Changqing LI, Gene McCALLISTER.
Application Number | 20120283643 13/466276 |
Document ID | / |
Family ID | 38335752 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120283643 |
Kind Code |
A1 |
LI; Changqing ; et
al. |
November 8, 2012 |
CATHETER ASSEMBLY INCLUDING INTERNAL BOLSTER
Abstract
A catheter assembly includes an internal bolster comprising a
plurality of resilient members collectively forming an anchor at a
first end of the catheter. Each resilient member is reversibly
transformable between a spiral shape, when at rest, and a
straightened shape, when forcibly unfurled. The catheter assembly
may be used in a method for inserting a gastrostomy tube into a
patient. The catheter assembly is inserted into the patient's
stomach with the resilient members in the unfurled straightened
state. Once the resilient members have entered the patient, the
resilient members are allowed to return to the relaxed spiral
shape, thereby anchoring the catheter assembly in the patient.
Inventors: |
LI; Changqing;
(Ellettsville, IN) ; McCALLISTER; Gene; (Spencer,
IN) |
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
38335752 |
Appl. No.: |
13/466276 |
Filed: |
May 8, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12974363 |
Dec 21, 2010 |
8192419 |
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13466276 |
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11389801 |
Mar 27, 2006 |
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12974363 |
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Current U.S.
Class: |
604/175 ;
604/174 |
Current CPC
Class: |
A61J 15/0038 20130101;
A61M 25/04 20130101; A61J 15/0015 20130101 |
Class at
Publication: |
604/175 ;
604/174 |
International
Class: |
A61M 25/04 20060101
A61M025/04 |
Claims
1. A catheter assembly comprising: (a) a catheter, the catheter
having a first end and a second end; and (b) an internal bolster
disposed at the first end of the catheter, the internal bolster
comprising a plurality of resilient members collectively forming an
anchor reversibly transformable between a radially expanded state
and a radially condensed state.
2. The catheter assembly as claimed in claim 1 wherein each of the
resilient members is reversibly transformable between a spiral
shape, when at rest, and a straightened shape, when forcibly
unfurled.
3. The catheter assembly as claimed in claim 2 wherein the spiral
shape extends radially outwardly from the catheter and towards the
second end of the catheter.
4. The catheter assembly as claimed in claim 2 wherein the spiral
shape extends radially outwardly from the catheter and away from
the second end of the catheter.
5. The catheter assembly as claimed in claim 1 wherein each of the
resilient members comprises a resilient wire and a protective
jacket, the protective jacket covering at least a portion of the
resilient wire.
6. The catheter assembly as claimed in claim 5 wherein each of the
resilient wires is coupled to a common base embedded in the
catheter.
7. The catheter assembly as claimed in claim 1 wherein the internal
bolster comprises exactly two resilient members.
8. The catheter assembly as claimed in claim 1 wherein the internal
bolster comprises more than two resilient members.
9. The catheter assembly as claimed in claim 8 wherein the internal
bolster comprises exactly six resilient members.
10. The catheter assembly as claimed in claim 1 wherein the
catheter and the resilient members form a unitary structure made
entirely of silicone rubber.
11. A catheter assembly comprising: (a) a catheter, the catheter
having a first end and a second end; and (b) a plurality of
resilient members disposed at the first end of the catheter, each
of the resilient members being reversibly transformable between a
spiral shape, when at rest, and a straightened shape, when forcibly
unfurled.
12. The catheter assembly as claimed in claim 11 wherein the spiral
shape extends radially outwardly from the catheter and towards the
second end of the catheter.
13. The catheter assembly as claimed in claim 11 wherein the spiral
shape extends radially outwardly from the catheter and away from
the second end of the catheter.
14. The catheter assembly as claimed in claim 11 wherein each of
the resilient members comprises a resilient wire and a protective
jacket, the protective jacket covering at least a portion of the
resilient wire.
15. The catheter assembly as claimed in claim 11 wherein there are
exactly two resilient members.
16. The catheter assembly as claimed in claim 11 wherein there are
exactly six resilient members.
17. A kit for use in implanting a catheter assembly in a patient,
the kit comprising: (a) a catheter assembly, the catheter assembly
comprising (i) a catheter, the catheter having a first end and a
second end, and (ii) an internal bolster disposed at the first end
of the catheter, the internal bolster comprising a plurality of
resilient members, each of the resilient members being reversibly
transformable between a spiral shape, when at rest, and a
straightened shape, when forcibly unfurled, the spiral shape
extending radially outwardly from the catheter and towards the
second end of the catheter; and (b) a delivery device, the delivery
device being a tubular member appropriately dimensioned to be
inserted over the catheter assembly from the second end of the
catheter and to unfurl the resilient members.
18. The kit as claimed in claim 17 wherein the delivery device has
a sharpened distal end.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to medical catheters
and relates more particularly to medical catheters of the type
having an internal bolster disposed at one end of said medical
catheter for retaining said end of said medical catheter within a
patient.
[0002] Certain patients are unable to take food and/or medications
transorally due to an inability to swallow. Such an inability to
swallow may be due to a variety of reasons, such as esophageal
cancer, neurological impairment and the like. Although the
intravenous administration of food and/or medications to such
patients may be a viable short-term approach, it is not well-suited
for the long-term. Accordingly, the most common approach to the
long-term feeding of such patients involves gastrostomy, i.e., the
creation of a feeding tract or stoma between the stomach and the
upper abdominal wall. (A less common approach involves jejunostomy,
i.e., the creating of a feeding tract or stoma leading into the
patient's jejunum.) Feeding is then typically performed by
administering food through a catheter or feeding tube that has been
inserted into the feeding tract, with one end of the feeding tube
extending into the stomach and being retained therein by an
internal anchor or bolster and the other end of the feeding tube
extending through the abdominal wall and terminating outside of the
patient.
[0003] Although gastrostomies were first performed surgically, most
gastrostomies are now performed using percutaneous endoscopy and
result in the implantation in the patient of a feeding
tube/internal bolster assembly (said feeding tube/internal bolster
assembly also commonly referred to as a percutaneous endoscopic
gastrostomy (PEG) device). Two of the more common percutaneous
endoscopic techniques for implanting a PEG device in a patient are
"the push method" (also known as "the Sacks-Vine method") and "the
pull method" (also known as "the Gauderer-Ponsky method").
Information regarding the foregoing two methods may be found in the
following patents, all of which are incorporated herein by
reference: U.S. Pat. No. 5,391,159, inventors Hirsch et al., which
issued Feb. 21, 1995; U.S. Pat. No. 5,167,627, inventors Clegg et
al., which issued Dec. 1, 1992; U.S. Pat. No. 5,112,310, inventor
Grobe, which issued May 12, 1992; U.S. Pat. No. 4,900,306,
inventors Quinn et al., which issued Feb. 13, 1990; and U.S. Pat.
No. 4,861,334, inventor Nawaz, which issued Aug. 29, 1989.
[0004] In addition to the above-described endoscopic techniques for
implanting PEG devices, there also exist direct percutaneous
techniques. Typically, such direct percutaneous techniques involve
(i) inserting an endoscope into the patient and, through
transillumination, identifying a desired insertion site; (ii) using
sutures or T-fasteners, placed one at a time, to secure the
abdominal wall to the stomach wall in a plurality of locations
surrounding the future insertion site; (iii) using a scalpel to
make an incision at the insertion site; (iv) using a series of
dilators to enlarge the insertion site opening until said opening
is large enough to pass therethrough the internal bolster at the
distal end of a gastrostomy tube; and (v) sliding an external
bolster over the proximal end of the gastrostomy tube down to skin
level over the T-fastener wires or sutures.
[0005] Other direct percutaneous techniques are disclosed in the
following patents and published patent applications, all of which
are incorporated herein by reference: U.S. Pat. No. 6,030,364,
inventors Durgin et al., which issued Feb. 29, 2000; U.S. Pat. No.
6,402,722, inventors Snow et al., which issued Jun. 11, 2002; and
U.S. Published Patent Application No. US-2004-0059293-A1, which was
published Mar. 25, 2004.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a novel
catheter assembly.
[0007] Therefore, according to one aspect of the present invention,
there is provided a catheter assembly comprising (a) a catheter,
said catheter having a first end and a second end; and (b) an
internal bolster disposed at said first end of said catheter, said
internal bolster comprising a plurality of resilient members
collectively forming an anchor reversibly transformable between a
radially expanded state and a radially condensed state.
[0008] According to one embodiment, the catheter assembly includes
a medical catheter preferably made of extruded silicone rubber. The
catheter is shaped to include a cylindrical wall defining a primary
longitudinal bore. A plurality of secondary longitudinal bores are
provided in the cylindrical wall, the secondary bores being evenly
spaced around the primary bore. The assembly also includes a
plurality of identical resilient members collectively forming an
anchor at a first end of the catheter. Each resilient member
comprises a resilient wire and a protective jacket. Each wire is
preferably made of a shape-memory material and is reversibly
transformable between a spiral shape that extends radially
outwardly and towards the second end of the catheter, when at rest,
and a straightened shape that extends away from the second end of
the catheter, when forcibly unfurled. One end of each wire is
disposed within a secondary bore of the catheter, with the
remainder of each wire extending out from the catheter. Each jacket
is preferably made of silicone rubber and encapsulates all of the
length of its wire, except for the small portion of the wire
inserted into the bore.
[0009] According to another embodiment, each resilient member is
made by insert-molding the protective jacket over the entirety of
the wire and then insert-molding the catheter around one end of
each of the plurality of resilient members.
[0010] According to still another embodiment, there is provided a
unitary insert shaped to include an annular base portion and a
plurality of resilient wires extending from the annular base
portion. Silicone rubber or a similarly suitable material is then
insert-molded over the insert to cover the resilient wires and to
define an associated catheter.
[0011] According to yet another embodiment, the resilient members
do not include an embedded wire, the catheter assembly instead
being a unitary structure made entirely of silicone rubber or a
similarly suitable material.
[0012] According to another aspect of the invention, there is
provided a catheter assembly comprising (a) a catheter, said
catheter having a first end and a second end; and (b) a plurality
of resilient members disposed at said first end of said catheter,
each of said resilient members being reversibly transformable
between a spiral shape, when at rest, and a straightened shape,
when forcibly unfurled.
[0013] According to yet another aspect of the invention, there is
provided a kit for use in implanting a catheter assembly in a
patient, said kit comprising (a) a catheter assembly, said catheter
assembly comprising (i) a catheter, said catheter having a first
end and a second end, and (ii) an internal bolster disposed at said
first end of said catheter, said internal bolster comprising a
plurality of resilient members, each of said resilient members
being reversibly transformable between a spiral shape, when at
rest, and a straightened shape, when forcibly unfurled, said spiral
shape extending radially outwardly from said catheter and towards
said second end of said catheter; and (b) a delivery device, said
delivery device being a tubular member appropriately dimensioned to
be inserted over said catheter assembly from said second end of
said catheter and to unfurl said resilient members.
[0014] For purposes of the present specification and claims,
various relational terms like "top," "bottom," "proximal" and
"distal" are used to describe the present invention when said
invention is positioned in or viewed from a given orientation. It
is to be understood that, by altering the orientation of the
invention, certain relational terms may need to be adjusted
accordingly.
[0015] Additional objects, as well as features and advantages, of
the present invention will be set forth in part in the description
which follows, and in part will be obvious from the description or
may be learned by practice of the invention. In the description,
reference is made to the accompanying drawings which form a part
thereof and in which is shown by way of illustration certain
embodiments for practicing the invention. The embodiments will be
described in sufficient detail to enable those skilled in the art
to practice the invention, and it is to be understood that other
embodiments may be utilized and that structural changes may be made
without departing from the scope of the invention. The following
detailed description is, therefore, not to be taken in a limiting
sense, and the scope of the present invention is best defined by
the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are hereby incorporated
into and constitute a part of this specification, illustrate
various embodiments of the invention and, together with the
description, serve to explain the principles of the invention. In
the drawings wherein like reference numerals represent like
parts:
[0017] FIGS. 1(a) and 1(b) are perspective and longitudinal section
views, respectively, of a first embodiment of a catheter assembly
constructed according to the teachings of the present invention,
the internal bolster of the catheter assembly being shown in an
expanded state;
[0018] FIG. 2(a) through 2(e) are fragmentary schematic views,
partly in section, illustrating the manner in which the catheter
assembly of FIGS. 1(a) and 1(b) may be implanted in a patient in
accordance with the teachings of the present invention;
[0019] FIGS. 3(a) and 3(b) are perspective and longitudinal section
views, respectively, of a second embodiment of a catheter assembly
constructed according to the teachings of the present invention,
the internal bolster of the catheter assembly being shown in an
expanded state;
[0020] FIGS. 4(a) and 4(b) are perspective and longitudinal section
views, respectively, of a third embodiment of a catheter assembly
constructed according to the teachings of the present invention,
the internal bolster of the catheter assembly being shown in an
expanded state;
[0021] FIG. 5 is a perspective view of the wire insert of the
catheter assembly of FIGS. 4(a) and 4(b);
[0022] FIGS. 6(a) and 6(b) are perspective and longitudinal section
views, respectively, of a fourth embodiment of a catheter assembly
constructed according to the teachings of the present invention,
the internal bolster of the catheter assembly being shown in an
expanded state;
[0023] FIG. 7 is a side view of the catheter assembly of FIGS. 6(a)
and 6(b), the internal bolster being shown in an unfurled state;
and
[0024] FIG. 8 is a perspective view of a fifth embodiment of a
catheter assembly constructed according to the teachings of the
present invention, the internal bolster of the catheter assembly
being shown in an expanded state.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Referring now to FIGS. 1(a) and 1(b), there are shown
perspective and longitudinal section views, respectively, of a
first embodiment of a catheter assembly constructed according to
the teachings of the present invention, said catheter assembly
being shown with its internal bolster in an expanded state, said
catheter assembly being represented generally by reference numeral
11.
[0026] Catheter assembly 11 includes a medical catheter 13 and an
internal bolster 15.
[0027] Catheter 13 is an elongated, unitary, tubular structure
preferably made of a flexible, biocompatible material, such as
silicone rubber. Catheter 13, which is preferably made by
extrusion, is shaped to include a cylindrical wall 17 terminating
in a first end 19 and in a second end 21, cylindrical wall 17
coaxially surrounding and defining a primary longitudinal bore 23.
As will be discussed further below, primary longitudinal bore 23 is
preferably used to convey fluids, such as food and/or medications,
to a patient in need thereof. A plurality of secondary longitudinal
bores 25 are provided in cylindrical wall 17, bores 25 being evenly
spaced around the periphery of primary longitudinal bore 23. As
will be discussed further below, secondary longitudinal bores 25
are used in the mounting of internal bolster 15 to catheter 13. A
series of ruler markings (not shown) are printed on catheter 13 and
extend several inches from first end 19 in the direction of second
end 21 to facilitate the cutting of catheter 13 to a desired length
after catheter 13 has been implanted in a patient.
[0028] Internal bolster 15 comprises a plurality of identical
resilient members 27 disposed at first end 19 of catheter 13,
resilient members 27 collectively functioning as a reversibly
transformable anchor. In the present embodiment, this anchor is in
the form of an iris diaphragm; however, the anchor may take forms
other than that of an iris diaphragm. Each resilient member 27
comprises a resilient wire 29 and a protective jacket 31. Each wire
29 is made of a material that permits its reversible transformation
between a spiral shape, when relaxed, and a straightened shape,
when forcibly unfurled. Examples of the materials that may be used
to make wire 29 include shape-memory materials, such as nitinol (a
nickel/titanium alloy), and elastomeric materials. Each wire 29 has
a first end 33 and a second end 35. The first end 33 of each wire
29 is disposed within a corresponding bore 25 of catheter 13, with
the remainder of each wire 29 extending out from first end 19 of
catheter 13. Each jacket 31, which is preferably made of silicone
rubber or a similarly flexible, biocompatible material,
encapsulates most of the length of wire 29, except for the small
portion of wire 29 inserted into bore 25. Each jacket 31 has a
first end 37 and a second end 39. First end 37 of jacket 31 is in
contact with first end 19 of catheter 13, and second end 39 of
jacket 31 extends for a distance beyond second end 35 of wire 29 so
that no part of wire 29 is exposed to the patient. Preferably, each
member 27 is made by (i) inserting first end 33 of wire 29 into
bore 25, first end 33 fitting within bore 25 by an interference
fit, (ii) straightening wire 29, and (iii) insert-molding jacket 31
around the exposed portion of straightened wire 29 and to catheter
13.
[0029] As can be seen, members 27 are oriented relative to catheter
13 so that (i) when each member 27 is in a relaxed state, said
member 27 spirals radially outwardly relative to catheter 13 and in
the direction of second end 21 of catheter 13 and (ii) when each
member 27 is in an unfurled state, said member 27 extends parallel
to the longitudinal axis of catheter 13, with its free end
extending away from first end 19 of catheter 13 in the direction
opposite to second end 21.
[0030] It should be understood that, although the present
embodiment includes six resilient members 27 spaced around first
end 19 of catheter 13, there could be as few as two resilient
members 27 spaced around first end 19 of catheter 13 or more than
six resilient members 27 spaced around first end 19 of catheter 13.
In addition, it should be understood that resilient members 27 are
not limited to assuming, when at rest, the particular spiral shape
shown in FIGS. 1(a) and 1(b). Rather, resilient members 27 may
instead form a looser curl, a tighter curl, a longer curl, a
shorter curl, a fatter curl, a thinner curl, etc. In addition,
there may be alternate geometries to spirals, such as balled or
knotted members, that may have improved strength. Moreover, there
may be various types of resilient members disposed around the
catheter.
[0031] Referring now to FIGS. 2(a) through 2(e), there is
schematically shown the manner in which catheter assembly 11 may be
implanted in a patient. (For illustrative purposes, catheter
assembly 11 is herein shown as an initial placement PEG device
being implanted in the stomach of a patient; however, it is to be
understood that catheter assembly 11 may be either an initial
placement device or a replacement device and may be implanted in
the stomach of a patient or at other locations within a patient
where the delivery and/or drainage of fluids is desirable.) First,
referring to FIG. 2(a), distal end D of endoscope E is inserted
into the stomach of a patient, and an intense light source L
disposed within endoscope E is used to transilluminate the stomach
wall S and the abdominal wall A of the patient so as to indicate
externally a desired incision site. Preferably, while the
aforementioned transillumination process is conducted, a supply of
gas is used to inflate the patient's stomach, thereby distending
the stomach and facilitating the transillumination process.
[0032] Next, as seen in FIG. 2(b), using a scalpel P, incisions are
made in the abdominal wall A and in the stomach wall S of the
patient at the desired incision site. Next, as seen in FIG. 2(c),
assembly 11 (which is not shown in section) is loaded into a
delivery device 51, delivery device 51 being a tubular member whose
inner diameter is appropriately dimensioned to receive assembly 11
and to unfurl members 27 to their respective straightened states.
As shown in the present embodiment, delivery device 51 preferably
has a sharpened distal end 53 to facilitate its insertion through
abdominal wall A and stomach wall S. Next, as seen in FIG. 2(d),
the distal ends of delivery device 51 and assembly 11 are inserted
through abdominal wall A and stomach wall S at the incision site.
It should be noted that, in addition to being used to straighten
members 27, delivery device 51 also provides stiffening support to
catheter 13, which possesses limited inherent stiffness and,
therefore, cannot easily be inserted by itself through the incision
site. Next, as seen in FIG. 2(e), while keeping assembly 11
stationary, delivery device 51 is withdrawn from the patient in the
direction indicated by arrow A. The removal of device 51 from
members 27 permits members 27 to assume their relaxed, expanded
states, thereby causing catheter 13 to be anchored within the
stomach of the patient. The implanted device may then be
endoscopically checked for proper placement, cut to a desired
length, and secured to an external bolster, Y-port and/or clamp in
the conventional manner. Food and/or medications may then be
delivered to the patient through the central bore of catheter
13.
[0033] When catheter assembly 11 is thus implanted in a patient,
catheter assembly 11 is preferably able to withstand a pull force
of about 14 pounds applied to second end 21 of catheter 13, without
permitting assembly 11 to be withdrawn from the patient.
[0034] To safely remove assembly 11 from a patient, one may insert
delivery device 51 over the implanted assembly 11, thereby causing
members 27 to be unfurled, and may then remove delivery device 51
and assembly 11 together from the patient.
[0035] Referring now to FIGS. 3(a) and 3(b), there are shown
perspective and longitudinal section views, respectively, of a
second embodiment of a catheter assembly constructed according to
the teachings of the present invention, the internal bolster of the
catheter assembly being shown in an expanded state, said catheter
assembly being represented generally by reference numeral 101.
[0036] Assembly 101 includes a catheter 103 and an internal bolster
105. Catheter 103 is an elongated, unitary, tubular structure
preferably made of a flexible, biocompatible material, such as
silicone rubber. Catheter 103 is shaped to include a cylindrical
wall 107 terminating in a first end 109 and in a second end 111,
cylindrical wall 107 coaxially surrounding and defining a
longitudinal bore 113 adapted to convey fluids, such as food and/or
medications, to a patient in need thereof. A series of ruler
markings (not shown) are printed on catheter 103 and extend several
inches from first end 109 in the direction of second end 111 to
facilitate the cutting of catheter 103 to a desired length after
catheter 103 has been implanted in a patient.
[0037] Internal bolster 105 comprises a plurality of identical
resilient members 127 collectively forming a reversibly
transformable anchor at first end 109 of catheter 103. In the
present embodiment, this anchor is in the form of an iris
diaphragm; however, the anchor may take forms other than that of an
iris diaphragm. Each resilient member 127 comprises a resilient
wire 129 and a protective jacket 131. Each wire 129 is made of a
material that permits its reversible transformation between a
spiral shape, when relaxed, and a straightened shape, when forcibly
unfurled. Examples of the materials that may be used to make wire
129 include shape-memory materials, such as nitinol (a
nickel/titanium alloy), and elastomeric materials. Each wire 129
has a first end 133 and a second end 135. Each jacket 131, which is
preferably made of silicone rubber or a similarly flexible,
biocompatible material, encapsulates the entire length of its wire
129. Each jacket 131 has a first end 137 and a second end 139.
[0038] Preferably, assembly 101 is made by insert-molding jacket
131 around each wire 129 to form each member 127 and then
insert-molding catheter 103 around the first end 137 of the six
members 127.
[0039] It should be understood that, although the present
embodiment includes six resilient members 127 spaced around first
end 109 of catheter 103, there could be as few as two resilient
members 127 spaced around first end 109 of catheter 103 or more
than six resilient members 127 spaced around first end 109 of
catheter 103. In addition, it should be understood that resilient
members 127 are not limited to assuming, when at rest, the
particular spiral shape shown in FIGS. 3(a) and 3(b). Rather,
resilient members 127 may instead form a looser curl, a tighter
curl, a longer curl, a shorter curl, a fatter curl, a thinner curl,
etc. In addition, there may be alternate geometries to spirals,
such as balled or knotted members, that may have improved strength.
Moreover, there may be various types of resilient members disposed
around the catheter.
[0040] Assembly 101 may be implanted, used and removed in the same
fashion as described above for assembly 11.
[0041] It should be understood that, instead of insert-molding
catheter 103 around the first end 137 of the six members 127, one
could simply bond the six members 127 to an end of a suitable
medical catheter.
[0042] Referring now to FIGS. 4(a) and 4(b), there are shown
perspective and longitudinal section views, respectively, of a
third embodiment of a catheter assembly constructed according to
the teachings of the present invention, the internal bolster of the
catheter assembly being shown in an expanded state, said catheter
assembly being represented generally by reference numeral 201.
[0043] Assembly 201 includes a catheter 203 and an internal bolster
205. Catheter 203 is an elongated, tubular structure made primarily
of a flexible, biocompatible material, such as silicone rubber.
Catheter 203 is shaped to include a cylindrical wall 207
terminating in a first end 209 and in a second end 211. Cylindrical
wall 207 coaxially surrounds and defines a longitudinal bore 213
adapted to convey fluids, such as food and/or medications, to a
patient in need thereof. A series of ruler markings (not shown) are
printed on catheter 203 and extend several inches from first end
209 in the direction of second end 211 to facilitate the cutting of
catheter 203 to a desired length after catheter 203 has been
implanted in a patient.
[0044] Internal bolster 205 comprises a pair of identical resilient
members 227 collectively forming a reversibly transformable anchor
at first end 209 of catheter 203. In the present embodiment, this
anchor is in the form of an iris diaphragm; however, the anchor may
take forms other than that of an iris diaphragm. Each resilient
member 227 comprises a resilient wire 229 and a protective jacket
231. Each wire 229 is made of a material that permits its
reversible transformation between a spiral shape, when relaxed, and
a straightened shape, when forcibly unfurled. Each wire 229 has a
first end 233 and a second end 235. The second ends 235 of the two
wires 229 are joined to a common annular base 236 to form a unitary
insert 241, base 236 being embedded within cylindrical wall 207 of
catheter 203 proximate to first end 209. (Insert 241 is shown
separately in FIG. 5.) Each jacket 231, which is preferably made of
silicone rubber or a similarly flexible, biocompatible material,
encapsulates the entire length of its wire 229.
[0045] Preferably, assembly 201 is made by injection molding insert
241 and then insert-molding silicone rubber or the like over insert
241.
[0046] It should be understood that, although assembly 201 includes
two resilient members 227, assembly 201 could be modified to
include more than two resilient members 227. In addition, it should
be understood that resilient members 227 are not limited to
assuming, when at rest, the particular spiral shape shown in FIGS.
4(a) and 4(b). Rather, resilient members 227 may instead form a
looser curl, a tighter curl, a longer curl, a shorter curl, a
fatter curl, a thinner curl, etc. In addition, there may be
alternate geometries to spirals, such as balled or knotted members,
that may have improved strength. Moreover, there may be various
types of resilient members disposed around the catheter.
[0047] Assembly 201 may be implanted, used and removed in the same
fashion as described above for assembly 11.
[0048] Referring now to FIGS. 6(a) and 6(b), there are shown
perspective and longitudinal section views, respectively, of a
fourth embodiment of a catheter assembly constructed according to
the teachings of the present invention, the internal bolster of the
catheter assembly being shown in an expanded state, said catheter
assembly being represented generally by reference numeral 301.
[0049] Catheter assembly 301 comprises a medical catheter 303 and
an internal bolster 305. Medical catheter 303 is an elongated,
tubular structure preferably made of a flexible, biocompatible
material, such as silicone rubber. Catheter 303 is shaped to
include a cylindrical wall 307 terminating in a first end 309 and
in a second end 311, cylindrical wall 307 coaxially surrounding and
defining a longitudinal bore 313 adapted to convey fluids, such as
food and/or medications, to a patient in need thereof. A series of
ruler markings (not shown) are printed on catheter 303 and extend
several inches from first end 309 in the direction of second end
311 to facilitate the cutting of catheter 303 to a desired length
after catheter 303 has been implanted in a patient.
[0050] Internal bolster 305 comprises a pair of identical resilient
members 327 collectively forming a reversibly transformable anchor
at first end 309 of catheter 303. In the present embodiment, this
anchor is in the form of an iris diaphragm; however, the anchor may
take forms other than that of an iris diaphragm. Each resilient
member 327 is reversibly transformable between a spiral shape, when
relaxed, and a straightened shape, when forcibly unfurled. As can
be seen, assembly 301 differs notably from assemblies 11, 101 and
201 in that members 327 are oriented relative to catheter 303 so
that (i) when each member 327 is in a relaxed state, said member
327 spirals radially outwardly relative to catheter 303 and in a
direction away from second end 311 of catheter 303 and (ii) when
each member 327 is in an unfurled state, said member 327 extends
parallel to the longitudinal axis of catheter 303, with its free
end 328 extending in the direction from first end 309 to second end
311.
[0051] Assembly 301 additionally differs from assemblies 11, 101
and 201 in that resilient members 327 do not include an embedded
wire. Instead, assembly 301 is preferably a unitary structure made
entirely of injection molded silicone rubber, said silicone rubber
being of sufficient strength for members 327 to retain catheter 303
in a patient.
[0052] It should be understood that, although the present
embodiment includes two resilient members 327 spaced around first
end 309 of catheter 303, there could be more than two resilient
members 327 spaced around first end 309 of catheter 303. In
addition, it should be understood that resilient members 327 are
not limited to assuming, when at rest, the particular spiral shape
shown in FIGS. 6(a) and 6(b). Rather, resilient members 327 may
instead form a looser curl, a tighter curl, a longer curl, a
shorter curl, a fatter curl, a thinner curl, etc. In addition,
there may be alternate geometries to spirals, such as balled or
knotted members, that may have improved strength. Moreover, there
may be various types of resilient members disposed around the
catheter.
[0053] Assembly 301 may be implanted in a patient in much the same
way as assemblies 11, 101 and 201, the principal difference being
that assembly 301 does not require the use of an extraneous
delivery device to straighten resilient members 327 during
implantation. This is because, due to the direction in which
resilient members 327 are coiled, one may simply hold members 327
in an unfurled state against the length of catheter 303 with one's
hand while inserting first end 309 of catheter 303 into the
patient. Once the free ends of resilient members 327 have entered
the patient and are released by the medical professional, they will
return to their expanded state on their own.
[0054] To remove assembly 301 from a patient, one simply pulls on
the external portion of catheter 303 until resilient members 327
unfurl.
[0055] It should be understood that, if desired, one could insert a
wire into each of the resilient members 327 of assembly 301.
[0056] Referring now to FIG. 8, there is shown a perspective view
of a fifth embodiment of a catheter assembly constructed according
to the teachings of the present invention, the internal bolster of
the catheter assembly being shown in an expanded state, said
catheter assembly being represented generally by reference numeral
401.
[0057] Catheter assembly 401 is similar in many respects to
catheter assembly 11, the principal difference between the two
assemblies being that catheter assembly 401 includes resilient
members 403, instead of resilient members 27. Resilient members 403
differ principally from resilient members 27 in that resilient
members 403, when at rest, assume a coiled shape that is
substantially non-planar or three-dimensional (i.e., the coils
extends laterally relative to the length of the resilient member)
whereas resilient members 27, when at rest, assume a spiral shape
that is substantially planar or two-dimensional. It should be
understood that, although the present embodiment includes two
resilient members 403, there could be more than two members 403.
Also, instead of using resilient members 403, one could use other
types of resilient members that have three-dimensional shapes to
increase the extent of engagement between the resilient members and
the patient, examples of such resilient members including
spiral-type resilient members that bend laterally or that twist
away from the perpendicular.
[0058] Assembly 401 may be implanted, used and removed in the same
fashion as described above for assembly 11.
[0059] In another embodiment (not shown), the resilient members are
disposed within the catheter during deployment and, thereafter, are
pushed out or pulled out of the catheter to assume their expanded
state.
[0060] In still another embodiment (not shown), instead of or in
addition to the automatic curling of the members forming the
anchor, the curling may be effected or locked by means of a
filament or the like. Such locking may involve the distal end of
the resilient member locking into itself or the catheter.
[0061] In still yet another embodiment (not shown), the distal end
of the catheter is made to include a plurality of resilient members
covered with a sheath. As the sheath is moved proximally relative
to the resilient members, the resilient members become uncovered
and are allowed to assume their relaxed, curled state. As more of
the length of the resilient members is exposed by continued
withdrawal of the sheath, the size of the curled resilient members
increases.
[0062] The embodiments of the present invention described above are
intended to be merely exemplary and those skilled in the art shall
be able to make numerous variations and modifications to it without
departing from the spirit of the present invention. All such
variations and modifications are intended to be within the scope of
the present invention as defined in the appended claims.
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