WO2012170460A2

WO2012170460A2 - Balloon-type fistula catheter

Info

Publication number: WO2012170460A2
Application number: PCT/US2012/040988
Authority: WO
Inventors: Yosuke Sakai
Original assignee: Tyco Healthcare Group LP
Current assignee: Covidien LP
Priority date: 2011-06-06
Filing date: 2012-06-06
Publication date: 2012-12-13
Anticipated expiration: 2013-12-06
Also published as: WO2012170460A3; JP2012249934A

Abstract

A balloon-type fistula catheter is disclosed wherein a balloon can reliably expand or contract and which is provided with a balloon-type part affixed inside the body that can reduce the burden on the surgeon and on the patient. The fistula catheter has shape memory rods that can be bowed radially outward at the portions of a guide groove in conjunction with the movement of a base end side main body part so as to expand the balloon by pushing from the inner surface side thereof.

Description

BALLOON-TYPE FISTULA CATHETER

Background

[0001] The present invention relates to a fistula catheter which is provided with a balloon-type part affixed inside the body, which is used to supply fluids such as liquid foods and nutrients into the digestive tract of a patient.

[0002] Parenteral nutrition, wherein liquid foods and nutrients are supplied using a fistula catheter, has been performed for people (patients) with reduced ability to ingest food orally due to old age or illness. For example, when percutaneous endoscopic gastrostomy (PEG) is used, a through-hole (a fistula such as a gastric fistula) is formed perforating the abdominal wall and the gastric wall of the patient and a fistula catheter is placed in the through-hole through which liquid food is fed to the patient through the fistula catheter.

[0003] Such fistula catheters used in parenteral nutrition is provided with a part affixed inside the body on the internal side of the wall of the digestive tract in the fistula used for ingestion provided in the abdomen of the patient, and a tube member, the tip of which is connected to the part affixed inside the body and the base of which extends through the fistula to outside the body of the patient. Fistula catheters can be classified into balloon-type or bumper- type, depending on the shape of the part affixed inside the body. Relative to the bumper-type, the balloon-type catheter typically has less frequency of injury to the fistula when replaced, and is more often used for home-care patients. The latter also can be easily replaced even by an inexperienced physician and it has the further advantage of posing less of a burden to the patient when replaced.

[0004] It has been disclosed that the balloon is made to function as the part affixed inside the body by injecting distilled water so as to expand the same (for example, see Publication of JP 2005-523077). In some fistula catheters with a balloon expanded by injecting distilled water, the distilled water in the balloon may gradually decrease after the catheter has been placed (e.g., by spontaneously discharged water). The decrease of distilled water in the balloon may cause the balloon to shrivel and may cause a decline in regularly check the status of the injected water in the balloon. However, the labor of regularly checking the status of the injected water in the balloon is extremely troublesome.

[0005] When detaching a balloon-type fistula catheter, the catheter is typically removed after discharging the distilled water n the balloon. In some cases, however, the distilled water may not be completely discharged from the balloon. The tendency for such an event to occur is particularly high when a fistula catheter has been used for a long time. In such instances, the balloon is deliberately ruptured. Although methods exist in order to deliberately rupture the balloon, such as forcibly injecting distilled water into the balloon or using another tool such as an endoscope, such techniques may not be preferable because there is a risk of causing complications to the patient and because of the increased burden on the surgeon.

Summary

[0006] The present invention advantageously provides a balloon-type fistula catheter provided with a balloon-type part affixed inside the body made such that the balloon can be reliably expanded and contracted which can reduce the burden on the surgeon and on the patient.

[0007] In accordance with one or more aspects, the balloon-type fistula catheter according to the present invention typically has a catheter part, an internal part which is typically a part affixed inside the body provided on the tip end side of the catheter part and placed in the wall of the digestive tract, and an external part which is typically a part affixed outside the body provided on the base end side of the catheter part maintaining the wall of the digestive tract and the abdominal wall between the part affixed inside the body. In accordance with some configurations pertinent to one or more aspects of the invention, the catheter part is typically provided with a multi-lumen tube having a plurality of sub-lumens on the outside of a main lumen, and the part affixed inside the body is typically provided with an expanding and self-contracting balloon and shape memory rods that ca modify the balloon. In accordance with some particular configurations of the invention, the shape memory rods in which the tip end sides can be supported at the outer circumference of the tip end of the main lumen and the base end sides thereof can be supported at the part affixed outside the body, can be inserted into the sub-lumens so that a portion thereof can be exposed from the sub-lumens to, preferably, create a state radially bowed outward at a portion exposed from the sub- lumens due to the tip ends and base ends thereof approaching in the axial direction which can then provide the balloon that can be expanded from the inner surface side.

[0008] In the balloon-type fistula catheter in accordance with one or more aspects of the present invention, the shape memory rods enter a nearly straight state in relation to the sub-lumens by axially distancing the tip ends and base ends thereof, and release the expansion from the inner surface side of the balloon.

[0009] In the balloon-type fistula catheter in accordance with one or more aspects of the present invention, the pail affixed outside the body is provided with a support part supporting the base end side of the shape memory rod, a tip end side main body pail supporting the base end side of the catheter part, and a base end side main body part which can be moved along with the support part, such that a bowed state and a nearly straight state can be maintained by the shape memory rods.

[00010] The balloon-type fistula catheter in accordance with one or more aspects of the present invention can have a protruding part that is projected radially outward on part of the periphery of the tip end side main body part, and can have a groove part on the base end side main body part that guides the protruding part. The movable range of the base end side main body part can be regulated by the groove part, and the base end side main body part and tip end side main body part can be locked by mating the protruding part to the terminating end of the groove part.

[00011] In the balloon-type fistula catheter in accordance with one or more aspects of the present invention, the shape memory rods can remember or has a tendency to retain the shape of the state bowed radially outward at the portion exposed from the sub- lumens. of the present invention can be expanded without the use of distilled water (or other liquid), which can obviate periodically checking or verifying the distilled water content in the balloon after placement, and which can significantly reduce the burden managing or maintaining the catheter by the surgeon or by the patient.

[00013] One or more aspects of the invention can be directed to a fistula catheter comprising a catheter part having a main lumen with an opening at an end thereof and a plurality of sub-lumens peripherally disposed around the main lumen; an external part at a base end of the catheter part, the external part comprising a plurality of through-holes, each of the plurality of through-holes aligned with one of the plurality of sub-lumens, a tip-end-main-body-part having a guide protrusion, a base-end-main-body-part having a groove part extending along the tip-end-main-body-part and a support, the guide protrusion engageable with the groove, the groove having a first locking part at a first end of the groove and a second locking part at a second end of the groove, and a flange-part projecting from a periphery of the tip-end-main-body-part; and an internal part at a tip end of the catheter part, the internal part having a plurality of guide grooves each deiming a channel, each of the plurality of guide grooves aligned with one of the plurality of sub- lumens, a tip flange disposed proximate the opening, a balloon, a plurality of shape rods, each of the plurality of shape rods disposed in one of the plurality of guide grooves, one of the plurality of sub-lumens, and one of the plurality of through-holes, each of the plurality of shape rods having a rod tip end and a rod base end, the rod tip end supported at the tip flange and each of the rod base end supported at the support of the base-end- main-body-part.

Description of the Drawings

[00014] An embodiment of the present invention is described herein with reference to the accompany drawings which are not drawn to scale.

[00015] Fig. 1 is a schematic illustration showing a front view of a fistula catheter according to a first embodiment, in accordance with one or more aspects of the invention. [00016] Fig. 2 is a schematic illustration showing a side view of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00017] Fig. 3 is a schematic illustration showing a cross-sectional view of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00018] Fig. 4 is a schematic illustration showing a cross-sectional view of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00019] Fig. 5 is a schematic illustration showing a cross-sectional view of the catheter part of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00020] Fig. 6 is a schematic illustration showing a front view of the expanded state of the balloon of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00021] Fig. 7 is a schematic illustration showing a side view of the expanded state of the balloon of the fistula catheter accordmg to the first embodiment, in accordance with one or more aspects of the invention.

[00022] Fig. 8 is a schematic illustration showing a cross- sectional view of the expanded state of the balloon of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00023] Fig. 9 is a schematic illustration showing a cross-sectional perspective view of the expanded state of the balloon of the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention.

[00024] Figs. 10(a) and 10(b) are schematic illustrations showing the operation for inserting/removing the fistula catheter according to the first embodiment, in accordance with one or more aspects of the invention. 10 multi -lumen tube, 11 main lumen, 11a tip flange part, 12 sub-lumens, 12a guide groove, 20 balloon, 21 shape memory rods, 30 tip end side main body part , 31a first through-hole, 31b second through-holes, 32 tip taper part, 33 peripheral surface, 33a protruding part, 34 flange part, 35 base end side main body part, 35a grove part, 35b gap part, 36 tip locking part, 37 base locking part, 38 support part, 39 partition plate, 50 tube, 71 stomach wall, 72 wall of the digestive tract, 73 fistula, A catheter part, B internal part or part affixed inside the body, and C external part or part affixed outside the body.

Detailed Description

[00026] As exemplarily illustrated, a fistula catheter 1 in accordance with one or more aspects of the invention can have a catheter part A, a part affixed inside the body B, and a part affixed outside the body C. Catheter part A is inserted into a fistula and serves to permit the flow of liquid food. Part affixed inside the body B is positioned in a wall of the digestive tract, such as the stomach wall, by placing into a fistula of the patient, and typically serves to prevent fistula catheter 1 from or being removed or dislodged or falling out of the fistula in the patient. Part affixed outside the body C, once fistula catheter 1 has been attached to the fistula, serves to hold or secure the wall of the digestive tract such as the stomach wail and the abdominal wall between the part affixed inside the body. The side of part affixed outside the body C illustrated on the upper part of the page is referred to as the base end side, and the side of part affixed inside the body B illustrated on the lower part of the page is referred to as the tip end side.

[00027] One or more aspects of the invention can be directed to fistula catheter.

One or more embodiments of the invention pertinent to one or more aspects of the invention can involve a fistula catheter comprising a catheter part having a main lumen with an opening at an end thereof, a plurality of sub- lumens peripherally disposed around the main lumen, and an internal part at a tip end of thereof; and an external part at a base end of the catheter part, the external part comprising a plurality of through-holes, each of the plurality of through-holes aligned with one of the plurality of sub-lumens, a tip-end- main-body-part having a guide protrusion, a base-end-main-body-part having a groove part extending along the tip-end-main-body-part, and a support, the groove having a first locking part at a first end of the groove and a second locking part at a second end of the groove, the guide protrusion engageable with the groove. The internal part can have a plurality of guide grooves each defining a channel, each of the plurality of guide grooves aligned with one of the plurality of sub-lumens, a tip flange disposed proximate the opening, a balloon, a plurality of shape rods, each of the plurality of shape rods disposed in one of the plurality of guide grooves, one of the plurality of sub-lumens, and one of the plurality of through-holes, each of the plurality of shape rods having a rod tip end and a rod base end, the rod tip end supported at the tip flange and each of the rod base end supported at the support of the base-end-main-body-part.

[00028] Further aspects of the invention can be directed to methods of preparing a fistula catheter. In accordance with one or more such aspects of the invention, the method can comprise providing a catheter part having a main lumen with an opening at an end thereof, a plurality of sub-lumens peripherally disposed around the main lumen, and an internal part at a tip end of thereof; and providing an external part at a base end of the catheter part, the external part comprising a plurality of through-holes, each of the plurality of through-holes aligned with one of the plurality of sub-lumens, a tip- end- main-body-part having a guide protrusion, a base-end-main-body-part having a groove part extending along the tip-end-main-body-part, and a support, the groove having a first locking part at a first end of the groove and a second locking part at a second end of the groove, the guide protrusion engageable with the groove. In accordance with one or more further embodiments, providing the catheter part can comprise providing the catheter part wherein the internal part has a plurality of guide grooves each defining a channel wherein each of the plurality of guide grooves can be aligned with one of the plurality of sub-lumens. In accordance with one or more further embodiments, providing the catheter part can comprise providing a tip flange disposed proximate the opening, a balloon, a plurality of shape rods, each of the plurality of shape rods disposed in one of the plurality of guide grooves, one of the plurality of sub-lumens, and one of the plurality of through-holes, each of the plurality of shape rods having a rod tip end and a rod base end, the rod tip end supported at the tip flange and each of the rod base end supported at the support of the base-end-main-body-part. [00030] Catheter part A links the outside of the patient's body with the inside of the patient's body, for example, intragastrically, and supplies fluids such as liquid foods and nutrients from outside the body of the patient into the body of the patient. The catheter part A is provided with a multi-lumen tube 10. Multi-lumen tube 10 is constituted of a resin material such as, for example, polyurethane resin, polyvinyl chloride resin, or silicone resin, and has a lumen (main lumen 11) for the passage of liquids such as liquid food thereinto. Also, multi-lumen tube 10 has the function of preventing the tendency of the fistula to close up when fistula catheter 1 is placed in a fistula formed in the abdomen of the patient.

[00031] As illustrated in Fig. 5, multi-lumen tube 10 has a plurality (four as exemplarily shown) of sub-lumens 12 on the outside or peripherally of main lumen 11. Main lumen 11 allows the passage of fluids such as liquid foods. Preferably, the inner diameter of sub-lumens 12 is made to be less than the wall thickness of multi-lumen tube 10. Sub-lumens 12 are sized and configured for shape memory rods 21, forming balloon 20 and part affixed inside the body B described below, to be inserted therethrough. In some cases, each of sub-lumens 12 is sized and configured for a shape memory rod 21, forming balloon 20 and part affixed inside the body B described below, to be inserted therethrough. Also, the number of sub-lumens 12 is not particularly limited, but three or more may be formed. In this case, sub-lumens 12 may be uniformly arranged, but they need not be distributed uniformly around main lumen 11.

[00032] Multi-lumen tube 10 is formed such that the axial length of sub-lumens 12 is shorter than the axial length of main lumen 11. Main lumen 11 is open-mouthed at the tip end and at the base end, and thus has the same axial length as multi-lumen tube 10. In contrast, sub-lumens 12 are open-mouthed at the base ends and the tip ends are positioned at the outer periphery of the tip end of main lumen 11. The outer periphery of the tip end of main lumen 11 is formed with a flange shape protruding radially outward, hereinafter referred to as tip flange part 11a. The wall surfaces of sub -lumens 12 between the base end surface of tip flange part 1 la to the base end side mounting part of balloon 20 described below are notched to act as guide groove 12a, such that shape memory rods 21 are exposed from sub-lumens 12. Preferably, at least a portion of shape memory rods is exposed at guide groove 12a. Also, if the tip ends of shape memory rods 21 described below can be supported, then the tip ends of sub-lumens 12 may be opened by perforating tip flange part 11a.

[00033] Part Affixed Inside the Body B

[00034] When fistula catheter 1 is inserted into a fistula in the patient, the shape of part affixed inside the body B is deformed from that of when fistula catheter 1 is placed in the fistula in the patient, and the same prevents the tendency of fistula catheter 1 to come out of the fistula in the patient when fistula catheter 1 has been placed in a fistula in the patient. The part affixed inside the body B has balloon 20 constituted of an expanding and self-contracting material, and shape memory rods 21 which deform the shape of balloon 20.

[00035] Balloon 20 is mounted at the tip end side of multi-lumen tube 10. Specifically, one end of balloon 20 is fixed to the periphery of tip flange part 1 la of main lumen 11, and the other end is mounted at the periphery of sub-lumens 12 that is positioned more to the base end side than the guide groove 12a, and is mounted so as to cover guide grooves 12a. The balloon 20 is formed with an expanding and self- contracting material (such as, for example, silicone resin). When fistula catheter 1 is placed in a fistula in the patient, the balloon 20 is deformed by expansion so as to provide resistance against the fistula and prevent the tendency of fistula catheter 1 to come out of the fistula in the patient.

[00036] In some configurations, balloon 20, rather than being expanded by injecting distilled water, can be deformed by the action of shape memory rods 21 so as to be pushed from within, and is in an expanded state when the inside is filled with air. With fistula catheter 1, because fluid such as distilled water is typically not used to expand balloon 20, there is no longer the tendency of balloon 20 to shrivel due to spontaneously discharged water, nor the tendency of the distilled water to be discharged therefrom. In some aspects of the invention, the plurality of shape memory rods 21 serves as ribs to support balloon 20 and can reduce pressure applied on any fluid contained therein. \.;ν/ν/.? j ine oase e d si ies ox n pe memory o is Δ ί arc iixcti s on _¾ described below and are inserted through second through-holes 31b of tip end side main body part 30 described below and through the sub-lumens 12, and the tip end sides thereof are fixed to the tip flange part 1 la via the guide groove 12a. Shape memory rods 21 are typically exposed at the guide groove 12a part. The shape memory rods 21 can be formed with a material so as to be able to maintain a prescribed shape when the part affixed inside the body is placed inside the body. The material of shape memory rods 21 is not particularly limited, but it may be formed

a shape memory alloy such as an alloy of titanium and nickel or an alloy of iron, manganese and silicon, for example, or with a thermoformable resin such as polypropylene (PP) or polyethylene (PE).

[00038] Shape memory rods 21 typically extend radially outward at the guide groove 12a part and can be configured to retain the shape of the state deformed so as to bow; the state in which balloon 20 is deformed by expansion. Balloon 20 fulfills the function of acting as part affixed inside the body B when in an expanded state, and shape memory rods 21 remember the shape so that balloon 20 can be in an expanded state.

[00039] Part Affixed Outside the Body C

[00040] When fistula catheter 1 is attached to the fistula, part affixed outside the body C holds the wall of the digestive tract, such as the stomach wall, and the abdominal wall between part affixed inside the body B, but can also prevent the tendency of fistula catheter 1 to be drawn into the body. The part affixed outside the body C comes into contact with the base end side periphery of catheter part A and includes tip end side main body part 30 fixedly supporting the base end side of catheter part A, base end side main body part 35 that covers tip end side main body part 30 when fistula catheter 1 is placed in the fistula, and support part 38 provided within base end side main body part 35 and fixedly supporting the base end sides of shape memory rods 21.

[00041] Tip end side main body part 30 is constituted of a roughly cylindrical member wherein a first through-hole 3 la is formed in the center thereof, and a plurality of second through-holes 31b are formed on the outside of first through-hole 31a. In tip end side main body part 30, tip taper part 32 is formed projecting out such that the diameter of the tip end side center part is progressively reduced towards the tip end, with the intention of facilitating mounting in the fistula and reducing resistance against the fistula. Accordingly, the axial lengths of first through-hole 31a and second through-holes 31b can include the tip taper part 32. The base end side of catheter part A is mounted at the tip end side of the first through-hole 31 a, and catheter part A is fixedly in contact therewith. Tube 50, which connects with catheter part A, is typically inserted into first through-hole 31a via base end side main body part 35. Thus, the tube 50 is typically made such that the tip thereof is inserted into the base of catheter part A and connects with catheter part A.

[00042] Second through-holes 31b have the same number as sub-lumens 12, and are made to be coaxial with sub-lumens 12 in the state wherei catheter part A has been mounted to the tip end side of first through-hole 31a. Second through-holes 31b can be configured such that shape memory rods 21, which extend from sub-lumens 12 in the base end side direction, can be inserted therethrough in an almost straight state. Note that herein, although the examples illustrate a state wherein second through-holes 31b have been provided, second through-holes 31b are not required, and shape memory rods 21 may be made to be inserted through first through-hole 31a.

[00043] Although not illustrated, if an optional check valve is provided at the part connecting catheter part A and tube 50, fistula catheter 1 can then to be used as a button- type fistula catheter.

[00044] Base end side main body part 35 is movably attached to peripheral surface 33 of tip end side main body part 30. Protruding part 33a is thus formed to project radially outward at a part of peripheral surface 33 of tip end side main body part 30. The protruding part 33a is made to be movable relative to groove part 35a formed in base end side main body part 35, and can be a lock mechanism in conjunction with groove part 35a. Although the examples show a state wherein only one protruding part 33a has been formed, the number of protruding parts 33a is not to be limited. Also, by providing a screw thread on peripheral surface 33 and providing a screw groove on base end side main body part 5, base end side main body part 35 may be made to attach to tip end side main body part 30 by using a screw construction. [00045] F urinermore, a flange part 34 can project radially outward at the periphery of the tip of tip end side main body part 30. The flange part 34 can be a stopper that prevents or at least partially inhibits lateral movement of the tip of base end side main body part 35. Flange part 34 can prevent or at least partially inhibit the tendency of fistula catheter 1 to be drawn into the body of the patient when fistula catheter 1 has been placed because the tip end surface thereof is typically in contact with the skin of the patient. It is furthermore intended to reduce invasiveness against the skin of the patient. The material constituting tip end side main body part 30 is not particularly limited, but tip end side main body part 30 may be formed with, for example, plastic parts such as polyurethane or other inert material.

[00046] Base end side main body part 35 is movably attached to peripheral surface 33 of tip end side main body part 30, such that nearly the entirety of tip end side main body part 30 is covered when fistula catheter 1 is placed in the fistula. Specifically, base end side main body part 35 moves so as to guide protruding part 33a of tip end side main body part 30 along grove part 35a. Axially extending groove part 35a can be configured so as to perforate a part of the side wall of base end side main body part 35 and guide the movement of protruding part 33a. The axial length of groove part 35a is determined by the degree to which base end side main body part 35, which is positioned at the base end side of tip end side main body part 30, contacts flange part 34 of tip end side main body part 30. The range of motion of base end side main body part 35 is typically determined by the groove part 35a.

[00047] Preferably, groove part 35a is terminated with a bent portion in the direction that is substantially orthogonal to the axial direction at the tip end and at the base end. By mating protruding part 33a to the terminating end, base end side main body part 35 is locked to tip end side main body part 30. In the description below, the tip end side terminating end of groove part 35a is called tip end side locking part 36, and the base end side terminating end of groove 35a is called base end side locking part 37. Also, although the material constituting base end side main body part 35 is not particularly limited, base end side main body part 35 may be formed out of plastic parts such as, for example, polyurethane or other inert material. Base end side main body part 35 and tip end side main body part 30 may be formed of different materials.

[00048] Support part 38 may be positioned at gap part 35b formed between partition plate 39, which is formed by projecting a portion of the inner wall surface of base end side main body part 35 radially inward, and the upper surface of base end side main body part 35, and can fixedly support the base end sides of shape memory rods 21 constituting the part affixed inside the body B. The support part 38 is preferably movable with base end side main body part 35, and accommodates moving the bases of shape memory rods 21 either toward the tip end side or toward the base end side of the part affixed outside the body B. Thus, support part 38, base end side main body part 35, and tip end side main body part 30 constitute a shaping mechanism making it possible to maintain the shape of shape memory rods 21 (in either a bowed state or in a nearly straight state). Specifically, it is possible to maintain the shape of the shape memory rods 21 by means of protruding part 33a, tip locking part 36, and base locking part 37.

[00049] Support part 38 may be constituted of plastic parts from, for example, polyurethane or other suitable material into a disc shape. The support part 38 is rotatable in the cncumferential direction relative to base end side main body part 35 without being fixed to base end side main body part 35. Note that the example illustrates cases wherein support 38 is disc-shaped, but it is not limited thereto, and may have a shape wherein the base end sides of the shape memory rods 21 are fixedly supported and can be movably mounted relative to the base end side main body part 35. Also, the examples describe embodiments wherein the base end side main body part 35 is configured so as to cover the tip end side main body part 30, but the tip end side main body part 30 may be configured so as to cover the base end side main body part 35.

[00050] Fig. 6 is a front view of the expanded state of balloon 20 of fistula catheter 1 according to the First Embodiment of the present invention. Fig. 7 is a side view of the expanded state of balloon 20 of fistula catheter 1. Fig. 8 is a cross-sectional schematic of the expanded state of balloon 20 of fistula catheter 1. Fig. 9 is a cross-sectional perspective view of the expanded state of balloon 20 of fistula catheter 1. The operation of fistula catheter 1 shall be explained based on Figs. 1-9.

m ain hrwiir r-.nri i c positioned at the base end side in an unexpanded state of balloon 20. The protruding part 33a enters a state mated to tip locking part 36 in the unexpanded state of balloon 20. When balloon 20 has not been expanded, the base end side main body part 35 is first rotated around the axis, and the protruding part 33a is unfastened from tip locking part 36. In doing so, the lock of the base end side main body part 35 is released, and it becomes possible to move the base end side main body part 35.

[00052] Base end side main body part 35 is moved to the tip end side of the tip end side main body part 30 while protruding part 33a is guided along grove part 35a. Once protruding part 33a reaches the tip end side of groove part 35a, base end side main body part 35 is not moved any further toward the tip end side of the tip end side main body part 30. Protruding part 33a is then mated to base locking part 37. In doing so, base end side main body part 35 is once again in a locked state, and the movement of the base end side main body part 35 is prevented.

[00053] In conjunction with the movement of the base end side main body part 35, the base end sides of the shape memory rods 21, which are fixedly supported by support part 38, are also moved toward the tip end side. However, in order to fix the tip end sides of the shape memory rods 21 to the tip flange part 11a, the shape memory rods 21 preferably extend radially outward at the uncovered exposed parts of second through- holes 31b and sub-lumens 12, at the guide groove 12a part, and are deformed so as to become bowed. The shape memory rods 21 are deformed so as to become bowed by causing the tip ends and base ends of the shape memory rods 21 to approach axially. In this way, shape memory rods 21 come into contact with the inside of balloon 20 and enter a state wherein balloon 20 is pushed outwardly from within.

[00054] At this time, a fluid such as air enters into balloon 20 via the second through-holes 31b, sub-lumens 12 and guide groove 12a, and balloon 20 enters an expanded state (the state illustrated in Figs. 6-9). Balloon 2 is deformed so as to be mechanically pushed from within by the action of the shape memory rods 21, and enters a state expanded by the influx of air. [00055] The shape memory rods 21 remember or have a tendency to form into the shape of this state (the state deformed so as to be bowed wherein they have extended radially outward at the guide grove 12a part), and are therefore able to maintain the expanded state of balloon 20. Accordingly, in fistula catheter 1, because distilled water is not used to expand balloon 20, the balloon 20 does not shrivel due to spontaneously discharged water, nor does distilled water discharge therefrom.

[00056] If it is desired to restore balloon 20 to the original state, the base end side main body part 35 is first rotated along the axis, and then the protruding part 33a is unclasped from base locking part 37. In doing so, the lock of the base end side main body part 35 is released, and the base end side main body part 35 can be moved.

[00057] Base end side main body part 35 is moved to the tip end side of the tip end side main body part 30 while protruding part 33a is guided along grove part 35a. Once protruding part 33a reaches the tip end side of groove part 35a, the base end side main body part 35 is not moved any further toward the base end side of the tip end side main body part 30. Protruding part 33a can be mated to tip locking part 36. In doing so, the base end side main body part 35 is in a locked state with the tip end side main body part 30, and the movement of the base end side main body part 35 is prevented.

[00058] In conjunction with the movement of the base end side main body part 35, shape memory rods 21, which are typically fixedly supported by support part 38, are also moved towards the base end side. By causing the tip ends and base ends of the shape memory rods 21 to approach axially, shape memory rods 21 are deformed to a state stretched to be nearly straight relative to sub-lumens 12. In so doing, shape memory rods 12, which have been stretched straight, are housed in guide groove 12a. Thus, shape memory rods 21 release pushing the inner surface side of balloon 20. As a result, balloon 20 also enters a deflatable state, and returns to the state illustrated in Figs. 1-4. Although shape memory rods remember or tend to the shape of the state deformed so as to be bowed by extending radially outward at the guide groove 12a parts, the nearly straight state is maintained in order to be in the state wherein the base end side main body part 35 is locked to the tip end side main body part 30. described with reference to Figs. 10(a)- 10(b), which are drawings illustrating operations for inserting/removing the fistula catheter in accordance with one or more embodiments of the invention.

[00060] As illustrated in Fig. 10(a), the fistula catheter 1 of the deflated state of balloon 20, the state wherein the base end side main body part 35 is positioned at the base end side of the tip end side main body part 30, is inserted into fistula 73 formed in abdominal wall 71 and wall of the digestive tract 72. The diameter of fistula catheter 1 is about the same as the maximum diameter of catheter part A added to the thickness of the deflated-state balloon 20, such that resistance when passed through fistula 73 is low. The risk of damage to fistula 73 is therefore low.

[00061] Thus, at an adequate insertion depth, once flange part 34 is in contact with the skin of the patient, catheter part A is held to the abdominal wall 71 side so as to not come out, while the surgeon twists the base end side main body part 35. By twisting with a force exceeding the mating force of the protruding part 33a and the tip locking part 36, the base end side main body part 35 is rotated along the axis, and the mated state of protruding part 33a and tip locking part 36 is released such that it becomes possible to move the base end side main body part 35.

[00062] The base end side main body part 35 can be moved to the tip end side. At this configuration, because the base end sides of the shape memory rods 21 are also moved therewith to the tip end side, the balloon 20 is deformed to an expanded state as illustrated in Fig. 10(b). To maintain the expanded shape of balloon 20, the base end side main body part 35 can be twisted in the opposite direction of the begimiing. In doing so, the base end side main body part 35 is rotated around the axis and protruding part 33a is mated to base locking part 37, such that base end side main body part 35 enters a locked state with the tip end side main body part 30.

[00063] In this way, balloon 20 enters an expanded state - a state wherein the part affixed inside the body B is formed - thus placing fistula catheter 1 within the wall of the digestive tract. Thus, in fistula catheter 1, placed in the digestive tract, the upper surface of balloon 20 (the base end side surface) comes into contact with the wall of the digestive tract 72. Because balloon 20 is constituted of a material having expansion and contraction properties, the contact thereof against wall of the digestive tract 72 is soft with little invasiveness against wall of the digestive tract 72. Accordingly, it is possible to reduce the risk of ulceration of the wall of the digestive tract or buried bumper syndrome. Also, because balloon 20 is maintained in an expanded state by the shape memory rods 21, the fixed state of the part affixed inside the body B inside wall of the digestive tract 72 is unlikely to be released, and unintentional removal such as spontaneous removal and the like is thereby prevented.

[00064] Furthermore, when an indwelling-state fistula catheter 1 is removed from fistula 73, balloon 20 of fistula catheter 1 may be removed in a deflated state by the opposite procedure from that of the time of insertion.

[00065] As above, according to fistula catheter 1, because it is possible to expand balloon 20 without using distilled water, it is not necessary to regularly check the distilled water content in balloon 20 once fistula catheter 1 has been placed. As a result, the labor of the one managing the catheter can be greatly reduced. Also, because balloon 20 can be mechanically expanded and contracted without using distilled water, there is no shriveling when removal is desired, and the insertion and removal operations of fistula catheter 1 can be reliably performed such that the burden on the patient is greatly reduced. Furthermore, according to fistula catheter 1, because a configuration that injects distilled water is not necessary, a small size for the part affixed outside the body C can be particularly realized.

[00066] What is claimed:

Claims

ί~Ί nitric

1. A balloon-type fistula catheter, comprising:

a fistula catheter that includes a catheter part, an internal part disposed on the tip end side of the catheter part and configured to be placed inside the wall of the digestive tract, and an external part disposed on the base end side of the catheter part configured to hold the wall of the digestive tract and the abdominal wall between the internal part, wherein the catheter part has a multi-lumen tube having a plurality of sub-lumens on a periphery of a main lumen; the internal part having a balloon and one or more shape memory rods configured to deform the balloon; and the shape memory rods, in which the tip end sides are supported at the peripheral part of the tip end of the main lumen while the base end sides are supported at the part fixed outside the body, are insertable into the sub-lumens so that a portion thereof is exposed from the sub-lumens, the memory rods deformable to be radially bowed outward at an exposed portion thereof from the sub- lumens when the tip ends and base ends thereof approach in the axial direction such that the balloon is expanded from the inner surface side,

2. The balloon-type fistula catheter according to Claim 1 , wherein the shape memory rods enter an almost straight state relative to the sub-lumens by causing the tip ends and base ends thereof to approach axially, so as to release the pushing from the inside surface side of the balloon.

3. The balloon-type fistula catheter according to Claim 1 wherein the shape memory rods can maintain a bowed state or a nearly straight state, and wherein the part affixed outside the body is provided with a support part that supports the base end sides of the shape memory rods, a tip end side main body part that supports the base end side of the catheter part, and a base end side main body part that has the ability to move in conjunction with the support part.

4. The balloon-type fistula catheter according to Claim 3, wherein a protruding part is provided that projects radially outward on a part of the periphery of the tip end side main body part, and a groove part is provided at the base end side main body part, which guides the protruding part, and the base end side main body part has a range of motion that is determined by the groove part, and the base end side main body part and the tip end side main body part are locked by mating the protruding part to the

terminating end of the grove part.

5. The balloon-type fistula catheter according to any one of Claims 1- 4, wherein the shape memory rods remember the shape of the state bowed radially outward at the portion exposed from the sub-lumens.

6. A fistula catheter, comprising:

a catheter part having a main lumen with an opening at an end thereof, a plurality of sub-lumens peripherally disposed around the main lumen, and an internal part at a tip end of thereof; and

an external part at a base end of the catheter part, the external part comprising a plurality of through-holes, each one of the plurality of through-holes aligned with one of the plurality of sub-lumens, a tip-end-main-body-part having a guide protrusion, a base- end-main-body-part having a groove part extending along the tip-end-main-body-part, and a support, the groove having a first locking part at a first end of the groove and a second locking part at a second end of the groove, the guide protrusion engageable with the groove,

the internal part having a plurality of guide grooves each defining a channel, each one of the plurality of guide grooves aligned with one of the plurality of sub-lumens, a tip flange disposed proximate the opening, a balloon, a plurality of shape rods, each one of the plurality of shape rods disposed in one of the plurality of guide grooves, one of the plurality of sub-lumens, and one of the plurality of through-holes, each of the plurality of shape rods having a rod tip end and a rod base end, each of the rod tip end supported at the tip flange and each of the rod base end supported at the support of the base-end -main- body-part.