CATHETER AND METHOD OF INSERTION

Abstract

A balloon catheter system includes a tube and a dilator detachable from the tube after the tube is inserted into a cavity in the patient. The cavity may be filled with gas or liquid to expand the viscera surrounding the cavity and the guidewire may be inserted using a trochar, for example. The tube includes one or more lumen to expandable balloons that are inflatable by fluid inserted through the lumen and into the balloon or balloons, which are formed by elastic film sealed on opposite ends to the external diameter of the tube. The dilator is held in place during insertion, such as by a stainless steel shaft and a sheath portion of the dilator extending over the end of the tube being inserted into the cavity. A portion of the sheath may extend over and protect the balloon. A retractor net may be used to capture and remove the dilator or the dilator may be designed as a bioabsorbable or digestible material or of a material that passes safely through the digestive tract of a patient.

Claims

1. A balloon catheter system for insertion into a patient, using a guidewire previously inserted into a cavity of the patient, the system comprising: a balloon catheter comprised of a tube having a first end, a second end opposite of the first end, a central bore fluidically coupling an inlet at the first end of the tube with an outlet at the second end of the tube and a lumen fluidically coupling a connector disposed adjacent the first end of the tube with a balloon disposed adjacent to the second end of the tube, the balloon being formed by a tubular film sealed at opposite aids of the tubular film to an external surface of the tube, the lumen having a lumen outlet such that fluid injected into the connector and through the lumen exits through the external surface of the tube at the lumen outlet and into an expandable cavity between the balloon, which is made of a flexible, resilient material, and the external surface of the tube, whereby the balloon is capable of being expanded by injecting fluid into the expandable cavity through the lumen; a dilator, comprised of a sheath portion extending from a solid body, the solid body having a central bore passing through the solid body such that an annular shaft passing through the central bore of the tube of the balloon catheter and the central bore of the solid body retains the dilator on the annular shaft at the second end of the tube, and the sheath portion extends seamlessly from a portion of the solid body having a first diameter, the first diameter being sized to an outer diameter of the tube such that the sheath portion extends over the outer diameter of the tube, and the solid body has a tip distal from the portion of the solid body having the first diameter, the tip having a second diameter, and the solid body having a transition region having an external diameter decreasing over a length of the transition region from the first diameter, larger than the second diameter, to the second diameter at the tip of the detachable dilator, the second diameter at the tip being substantially the same as an outer diameter of the annular shaft, where the tip, distal from the portion of the solid body having the first diameter, extends from the outer diameter of the annular shaft, and the annular shaft having an inner diameter greater than the diameter of the guidewire, such that the guidewire is insertable into the inner diameter of the annular shaft, and the annular shaft is guidable over the guidewire, the dilator being engaged on the annular shaft, such that, the dilator extends into the cavity of the patient as the annular shaft is guided over the guidewire, and when the annular shaft is withdrawn from the central bore of the tube the dilator detaches from the annular shaft and remains in the cavity of the patient.

2. The balloon catheter system of claim 1, wherein the annular shaft is of a stainless steel.

3. The balloon catheter system of claim 2, wherein the annular shaft has a pointed tip extending from the dilator.

4. The balloon catheter system of claim 1, wherein the sheath portion of the detachable dilator is formed of a flexible, resilient material, and the sheath portion closes in on itself, when the detachable dilator is detached from the tube.

5. The balloon catheter system of claim 1, wherein the dilator is made of a digestible material.

6. The balloon catheter system of claim 1, wherein the sheath portion is made of a digestible material.

7. The balloon catheter system of claim 1, wherein the external diameter of the transition region changes non-linearly with length.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGS. 1A-1C illustrate a detachable dilator as seen (A) externally and (B) in a cross sectional view, while the sheath portion is spread for insertion of the catheter tube, and (C) in a cross sectional view with the sheath portion folded in on itself.

[0018] FIG. 2 illustrates an example of the use of a detachable dilator, shown in cross section, fitted with a needle introducer and a balloon catheter.

[0019] FIG. 3 illustrates another example of the use of a detachable dilator, shown in cross section, fitted with a needle introducer, a balloon catheter, in partial cross section, and an example of a detacher.

[0020] FIG. 4 illustrates a perspective view of an example of a detacher head.

[0021] FIG. 5 illustrates a perspective view of an example of a detacher handle.

[0022] FIG. 6 illustrates a partially exploded view of a detacher head, a detacher handle and a needle introducer.

[0023] FIG. 6A illustrates a perspective view of an example of a double balloon feeding tube with both balloons expanded; FIG. 6B illustrates a cross sectional view of the feeding tube of FIG. 6A.

[0024] FIG. 7 illustrates a detail, perspective view of a balloon separate from the feeding tube.

DETAILED DESCRIPTION

[0025] The examples described and the drawings rendered are illustrative and are not to be read as limiting the scope of the invention as it is defined by the appended claims.

[0026] The method of insertion of a balloon catheter using a detachable dilator is similar to the procedure used in the Nath Application. However, instead of withdrawing the needle with a flexible sheath through the large channel in the feeding tube of the Nath Application, only the needle introducer is withdrawn through the catheter. The dilator is detached from the catheter after insertion of the catheter. In one example, the dilator is made of a biocompatible and/or digestible polymer. For example, a polytetrafluoroethylene may be used for the dilator and provides exceptional biocompatibility together with advantageous tribology. However, other polymer materials may be used, such as polyvinylchloride, polyethylene, polypropylene, polyethylene terephthalate, other polyesters, polymethylmethacrylate, polycarbonates, polyamides, polyacetals, polysulfones and co-polymers, such as tetrafluoroethylene and hexafluoropropylene and polyurethane block co-polymers.

[0027] In one example, the dilator is withdrawn using minimally invasive techniques. For example, a snare, such as one of the net-like snares capable of being used with an endoscope, is used to capture and remove the dilator. For example, a Roth Net® foreign body standard snare may be used..sup.1

[0028] In other examples, the dilator is not withdrawn but is made of a bioabsorbable or digestible material or a material that passes harmlessly through the digestive tract. For example, a dilator may be made of a polylactide, which exhibits high tensile strength and rigidity, but hydrolyzing breaks the polylactide down to lactic acid, which digestible or passes harmlessly through the digestive tract. Other bioabsorbable materials include poly(trimethyl carbonate), poly(carbonate) and starch-based polymers and gels, which may provide sufficient rigidity to serve as a dilator.

[0029] FIG. 1A illustrates a dilator 10, having an asymmetric nose 14 and an integrally formed protective sheath 12, as illustrated in the cross sectional view of FIG. 1B. In FIG. 1C, a resilient, flexible material, such as PEEK or silicone rubber, is used to form the sheath portion of the dilator, and the sheath portion is capable of returning to a shape folded in on itself. This may make it possible for the dilator to pass through the digestive tract with no harm to the patient, for example, and reduces the length of the dilator, if it is to be captured by a net, for example. FIG. 2 illustrates use of the detachable dilator 10 with a needle introducer 20 and a tri-funnel balloon catheter 30. The tip 22 of needle introducer 20 is inserted through a channel defined by the inner diameter of the annular dilator 10. In one example, the needle introducer 20 and dilator 10 are sized, such that the needle introducer may be withdrawn from the dilator 10 and the catheter 30 by pulling the protector 24 while pushing on the catheter 30 to keep the catheter 30 stationary. In this way, both the needle introducer 20 and a guide wire inserted through the needle introducer may be withdrawn from the catheter 30. The dilator 10 is then free to be detached from the catheter 30. In one example, an integrally formed sheath 12 is thin, such as less than 1 millimeter in thickness, and non-rigid, and the dilator 10 dislodges from the catheter 30 as soon as the needle introducer 10 is removed. Alternatively, the dilator 10 may be dislodged from the catheter 30 by expanding the balloon 38, which is attached at the end of the catheter 30 by adhesive bonds 39 on each end of the balloon, for example. A balloon lumen 56 may be coextruded such that fluid inserted by syringe at the luer lock 58 inflates the balloon with a liquid, such as water or saline. A plurality of balloons may be provided by having additional coextruded balloon lumen, for example. The sheath 12 may protect each of the plurality of balloons, a single balloon or a portion of a single balloon. FIG. 2 illustrates a sheath protecting a leading edge of a balloon 38, for example. .sup.1 ROTH NET® is a trademark of US Endoscopy.

[0030] An external bolster 40 provides a flange 42 that may be slid downward, once the balloon 38 is inflated and the catheter 30 is in place. In the example of FIGS. 2 and 3, a tri-funnel connector 50 is attached to the tube of the catheter by a transition region 32. The catheter has a main feeding channel, which may be closed by a flexibly attached plug 51 and a secondary drainage port 52, which may be connected to a drainage bag. The main channel may be flushed with sterile water or saline to keep the catheter free of obstructions and dots. A second plug 53 may be used to close the drainage port 52, when it is not being used. A luer lock 58 seals the balloon inflation lumen 56, which may be used to fill or drain the balloon 38 using a syringe.

[0031] FIG. 3 illustrates the use of a detachment mechanism 60, 70, which includes a head 60, a handle 70 and a hollow push rod 61, which has a channel through which the needle introducer 20 extends, when preassembled prior to insertion, for example. As illustrated in FIG. 4, the head 60 has finger holds 69 on one end and slots or channels 64, 66 on the opposite end. The slots 64, 66 are dimensioned to accommodate the narrow portions 74 of the handle 70. A central bore 67 of the head 60 is sized to accommodate the diameter of the push rod 61. The push rod 61 is coupled to the handle 70 and one end of the push rod 61 extends from one side of the handle 70. The opposite end of the push rod 61 is capable of contacting the dilator 10 to force detachment of the dilator 10 from the catheter 30, when the handle 70 is backed-off, and rotated 90 degrees in the head 60, as illustrated in FIG. 6, aligning the narrow portion 74 of the handle 70 with the elongated channels 66. The user's fingers may compress the finger holds 76 of the handle 70 toward the finger holds 69 of the head 60, which are reinforced by arcuate supports 68. The head 60 has a funnel shape surrounding the central bore 67, which provides a centering function when the push rod 61 is inserted into the central bore 67. A tapered retention plug 62 extends from the tubeward side of the head 60 and is capable of mating with the main channel of the tri-funnel connector 50 as illustrated in FIG. 3. A slightly tapered plunger barrel 72 extends into the head 60 and acts to guide the handle 70 into the head 60 during compression. The handle 70 includes a central bore 71 that is capable of accommodating the needle introducer 20, as illustrated in FIG. 6. The protector 24 on the outward end of the needle introducer 20 may be held with one hand, while the other hand is used to plunge the handle into the head, keeping the needle introducer 20 in place while the dilator 10 is detached from the catheter 30. Alternatively, the needle introducer may be withdrawn prior to detaching the dilator 10 using the detachment mechanism 60, 70.

[0032] In FIG. 6A-6B, a double balloon (dumbbell-shaped) catheter is illustrated. The addition of a second balloon 88, in addition to the balloon nearest the outlet of the catheter 38, is provided to use in patients where a single balloon is insufficient. One or both of the balloons may have a larger volume than a single balloon device. For example, if a single balloon device has a balloon is filled with 20 cubic centimeters of liquid, and then one or both of the double balloons may be filled with 40 cubic centimeters of liquid. Alternatively, each balloon may be filled with the same volume of liquid, for example 20 cubic centimeters. In one example, each of the balloons in the double balloon device are capable of being filled to a maximum volume of 120 cubic centimeters, and use of the catheter is indicated for obese patients that have failed to control weight through diet and exercise. Each balloon has its own, independent luer lock 58, 59 and lumen 56, 59 for expansion and contraction of the balloon volumes in FIGS. 6A-6B. The gap between the two balloons 38,88 provides a path for food and liquid to pass from the esophagus, through the stomach and to the intestines. A feeding port and drainage port are provided as illustrated in the single balloon catheter of FIGS. 2-3.

[0033] A typical balloon 38 is illustrated in FIG. 7, and the adhesive layer 39 is represented by the cross-hatched region on the end of the balloon.

[0034] Additional examples and configurations of the features of the examples shall be understood based on these examples and are intended to be included within the scope of the claims, which are not to be limited by the details of the examples provided.