WO2010126786A1

WO2010126786A1 - Aspiration catheter with thrombus removing device

Info

Publication number: WO2010126786A1
Application number: PCT/US2010/032171
Authority: WO
Inventors: Kurt J. Tekulve; Meridith A. Cavett
Original assignee: Cook Incorporated
Priority date: 2009-05-01
Filing date: 2010-04-23
Publication date: 2010-11-04

Abstract

The present disclosure provides an aspiration catheter (20) for removing thrombus from a lumen of a hemodialysis catheter (100). One embodiment of the aspiration catheter comprises an elongate flexible shaft having a proximal end and a distal end. The aspiration catheter further comprises an operable device at the distal end of the elongate flexible shaft to be inserted through the lumen of the hemodialysis catheter. The operable device (30) is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter. The operable device is configured to engage and remove thrombus from the lumen of the hemodialysis catheter. The aspiration catheter further comprises a source of negative pressure. The aspiration catheter further comprises a connector adapted to connect the source of negative pressure and the proximal end of the elongate flexible shaft. The elongate flexible shaft is configured to draw debris into the aspiration catheter.

Description

ASPIRATION CATHETER WITH THROMBUS REMOVING DEVICE

BACKGROUND

[0001] The present disclosure relates generally to apparatus and methods for catheters, and more specifically, for an aspiration catheter or an aspiration apparatus with a thrombus removing device.

[0002] Catheters have been introduced as a minimal invasive device in many medical applications for temporary catheterization such as clot aspiration and long term catheterization such as hemodialysis. Hemodialysis catheters usually stay in the subject body for extended periods of time (e.g. several weeks or more) to withdraw fluid from the body for processing and simultaneously introduce processed fluid back into the body. Although hemodialysis catheters are minimally invasive, they are foreign to the body and may cause an inflammatory reaction. The reaction may introduce thrombus around the surface of hemodialysis catheters especially on the catheter tip. The thrombus may obstruct or even completely block the fluid flow in the hemodialysis catheters, which will result in a low blood flow rate and insufficient hemodialysis. [0003] Various devices and procedures are known for removing thrombus and keep the patency of hemodialysis catheters. A device such as a J-tipped guide wire or a biopsy brush can be passed through the obstructed hemodialysis catheter to remove thrombus from the lumens of the catheter. Thrombolytic agents can also be infused into the catheter to remove thrombus from the lumens. External snares have also been used to remove thrombus from the outside of the catheter by advancing the snare alongside the hemodialysis catheter and looping the snare over the distal end thereof. However, the advance of and manipulation of an external snare is difficult and time consuming. Moreover, the presence of thrombus may make it impossible to loop the snare over the end of the catheter.

SUMMARY

[0004] The present disclosure provides apparatus and methods for removing thrombus inside or outside of a hemodialysis catheter by providing an aspiration catheter with an operable member configured to be advanced through a lumen of the hemodialysis catheter. [0005] One embodiment of the aspiration catheter for removing thrombus from a hemodialysis catheter comprises an elongate flexible shaft having a proximal end and a distal end. The aspiration catheter further comprises an operable device at the distal end of the elongate flexible shaft configured for insertion through a lumen of the hemodialysis catheter. The operable device is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter. The operable device is configured to engage and remove thrombus from the hemodialysis catheter. The aspiration catheter further comprises a source of negative pressure. The aspiration catheter further comprises a connector adapted to connect the proximal end of the elongate flexible shaft to the source of negative pressure. The elongate flexible shaft is configured to draw debris into the aspiration catheter.

[0006] In one embodiment, the operable device comprises a rod and an expandable brush device fixed to the distal end of the rod, wherein the operable device is advanceable through the lumen of the aspiration catheter and beyond a distal end thereof. In another embodiment, the operable device is fixed to the distal end of the aspiration catheter. In either embodiment, the operable device is capable of being extended beyond a distal end of a lumen of a hemodialysis catheter and is configured to engage and remove thrombus from the hemodialysis catheter. [0007] In another embodiment, the elongate flexible shaft of the aspiration catheter has a tapered, angled, bent, or curved tip. An operable device is fixed to the nonlinear tip of the elongate flexible shaft.

[0008] A method to use the above embodiment of the aspiration catheter for removing thrombus inside or outside of a hemodialysis catheter includes providing an aspiration catheter having an operable device and a source of negative pressure. An operator inserts the aspiration catheter into a lumen of the hemodialysis catheter. The operator manipulates the operable device to break up thrombus. The operator then removes the broken thrombus. In particular, the operator may adjust the source of negative pressure to aspire the broken thrombus and debris.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The disclosure can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.

[0010] FIG. 1 is a side view of a first embodiment of an aspiration catheter for removing thrombus off the hemodialysis catheter with an operable device.

[0011] FIG. 2 is a side view of the first embodiment of the aspiration catheter disposed in a hemodialysis catheter.

[0012] FIG. 3 is a side view of a second embodiment of an aspiration catheter for removing thrombus off the hemodialysis catheter with an operable device.

[0013] FIG. 4 is a side view of a third embodiment of an aspiration apparatus for removing thrombus off the hemodialysis catheter with an operable device.

[0014] FIG. 5 is a side view of the third embodiment of the aspiration apparatus disposed in a hemodialysis catheter.

[0015] FIG. 6 is a side view of a fourth embodiment of an aspiration catheter for removing thrombus off the hemodialysis catheter with an operable device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In the present application, the term "proximal" refers to a direction that is generally toward a physician during a medical procedure, while the term "distal" refers to a direction that is generally toward a target site within a patient's anatomy during a medical procedure. [0017] Referring now to FIG. 1 and FIG. 2, a first embodiment of an aspiration catheter 20 for hemodialysis treatment is described. The aspiration catheter 200 may be disposed in a lumen of a hemodialysis catheter 100. The hemodialysis catheter 100 comprises an elongate shaft 80 comprising a first lumen 60, a second lumen 70, and a fitting 40, as shown in FIG. 2. The first lumen 60 and the second lumen 70 may have a first fitting 65 and a second fitting 75, respectively. The hemodialysis catheter 100 has a proximal portion 2 and a distal portion 4. The aspiration catheter 200 comprises an elongate flexible shaft 20, an operable device 30, a source of negative pressure 51, and a connector 24, as shown in FIG. 1. The elongate flexible shaft 20 has a proximal end 22 and a distal end 26. The source of negative pressure 51 may be a syringe. The connector 24 may be adapted to connect the source of negative pressure 51 and the proximal end 22 of the elongate flexible shaft 20. The distal end 26 may be curved or angled to facilitate engagement of the operable member 17 with the hemodialysis catheter 100. The aspiration catheter 200 may be inserted through the first lumen 60 of the hemodialysis catheter 100. More specifically, the operable device 30 at the distal end 26 of the elongate flexible shaft 20 may be inserted through the first lumen 60 of the hemodialysis catheter 100. The operable device 30 may be extended beyond a distal end 66 of the first lumen 60 of the hemodialysis catheter 100. The operable device 30 may be configured to engage and remove thrombus from one of the first lumen 60 and the second lumen 70 of the hemodialysis catheter.

[0018] The operable device 30 comprises an operable member 17. The operable member 17 may have an angled, bent, curved, or tapered tip attached near the distal end. The operable member 17 may comprise an expandable brush near the distal end 15 configured to engage and remove thrombus from a lumen of the hemodialysis catheter 100. The operable member 17 may also comprise, for example, an expandable snare or a retrievable basket device. The operable device 30 may further comprise a hook device 19 near the distal end 15 configured to engage and remove thrombus from a lumen of the hemodialysis catheter 100. The operable device 30 may further comprise a controller 11 near a proximal portion 12 of the operable device 30. The controller 11 may be used by an operator to manipulate or control the position of the operable member 17. The operable device 30 may further comprise a rod 10 with the hook device 19 fixed thereon near the distal end configured to engage and remove thrombus from the hemodialysis catheter 100. The distal portion of the rod 10 may be angled or curved to facilitate engagement of the operable member 17 with the hemodialysis catheter 100. The removed thrombus and debris may be further removed from the blood vessel through the aspiration catheter 200.

[0019] The connector 24 may be a three way Toughy Borst connector. The connector 24 may further comprise a tighten down fitting or other sealable fitting. The connector 24 is used to hook up the aspiration catheter 200 and the source of negative pressure 51. The source of negative pressure 51 may be a syringe. The syringe may be connected to the connector 24 using a side connector 55. Adapters 23 and 53 may be used to further improve the hermetic connections between the source of negative pressure 51 and the aspiration catheter 200. [0020] During a hemodialysis treatment, an operator such as a doctor or a nurse uses the above described aspiration catheter 200 to remove the accumulated clot or thrombus around the inside or outside surface of the hemodialysis catheter 100. More specifically, the aspiration catheter 200 is used to break up and aspirate the thrombus around a first distal port 62 of the first lumen 60 and/or a second distal port 72 of the second lumen 70.

[0021] In the first step, the operator inserts the aspiration catheter 200 with the operable device 30 to the first lumen 60 or the second lumen 70 of the hemodialysis catheter 100. The operable device 30 may be extended beyond the first distal port 62 or the second distal port 72 of the hemodialysis catheter 100. The operable device 30 may be in a contracted state when it is inside of the aspiration catheter 200. The operable device 30 may be in an expanded state when it is outside of the aspiration catheter 200. Preferably, the operator may expand and retrieve the operable member 17.

[0022] In the second step, the operator manipulates the operable device 30 to break up the thrombus. Preferably, the operator may manipulate the operable device 30 with the help of a medical imaging device such as a real time ultrasound imaging system. The operator may twist the operable member 17 back and forth to clear thrombus.

[0023] In the third step, the operator adjusts the source of negative pressure 51 to create a vacuum. More specifically, the operator may pull a syringe to aspire the broken thrombus and debris. Once the syringe is pulled down, then the operable member 17 would be pulled back catching any thrombus flapping around the distal portion 4 of the hemodialysis catheter 100. The operable member 17 may be collapsed as it is pulled back.

[0024] In the final step, the operator may remove the aspiration catheter 200 with the operable device 30 for cleaning or other purposes. The operator may remove the operable device 30 only. The operator may pull back the operable member 17 and clean the operable member 17. If there is no more thrombus, the operator may remove the aspiration catheter 200 and the operable device 30.

[0025] The operable device 30 may be rigid or flexible as desired. The operable device 30 may be manufactured from a material, e.g., PEBAX, nylon, Hytrel, Arnitel, stainless steel, Nitinol, or other metals or polymers, which may be suitable for use during an interventional procedure. The operable member 17 may be made from rigid or flexible material. The operable member 17 may be inflated or deflated by an operator through the operable device 30. The rod 10 may be made from Nitinol, stainless steel, or other metals that would be suitable for use. [0026] Additionally, or alternatively, the operable member 17 may comprise therapeutic agents to improve the performance and efficiency of removing clots, thrombus or other undesired material.

[0027] A second embodiment of an aspiration catheter for removing thrombus from a hemodialysis catheter is shown in FIG. 3. The aspiration catheter 200 comprises an elongate flexible shaft 20 having a proximal end 22 and a distal end 26. The aspiration catheter 200 further comprises an operable device 30 extending and fixed to the distal end 26 of the aspiration catheter 200. The aspiration catheter 200 may be configured for insertion through a lumen of the hemodialysis catheter. The operable device 30 is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter. The operable device 30 is configured to engage and remove thrombus from the hemodialysis catheter. The aspiration catheter 200 further comprises a source of negative pressure 51. The aspiration catheter 200 may further comprise a connector 24 adapted to connect the source of negative pressure 51 and the proximal end 22 of the elongate flexible shaft 20. The elongate flexible shaft 20 is configured to draw debris into the aspiration catheter 200.

[0028] One of the differences between the first embodiment and the second embodiment of the aspiration catheter is that the operable device 30 is fixed to the distal end 26 of the aspiration catheter 200. The operator is capable of manipulate the operable device 30 by manipulating the aspiration catheter 200 directly.

[0029] The operable device 30 comprises an operable member 17 configured to engage and remove thrombus from a hemodialysis catheter. The operable member 17 may be collapsed while being disposed inside a lumen of the hemodialysis catheter. The operable member 17 may be expanded to break the thrombus. The operable device 30 may further comprise a hook 19 configured to engage and remove thrombus from the hemodialysis catheter. The operable device 30 may be bended if necessary to break and remove thrombus. [0030] The connector 24 is used to hook up the aspiration catheter 200 and the source of negative pressure 51. The source of negative pressure 51 may be a syringe. The syringe may be connected to the connector 24 using an adapter 53. An adapter 23 may be used to further improve the hermetic connections between the source of negative pressure 51 and the aspiration catheter 200.

[0031] When using the second embodiment of the aspiration catheter 200, an operator manipulates the operable device 30 to break thrombus from a hemodialysis catheter while adjusting the source of negative pressure 51. The operator may catch and remove broken thrombus by adjusting the source of negative pressure 51 and manipulating the operable device 30 simultaneously. Thus the thrombus can be broken and removed from the hemodialysis catheter and the blood vessel at the same time. No debris would be left to cause any problem. [0032] Another embodiment of an aspiration apparatus 200 for removing thrombus from a hemodialysis catheter is shown in FIG. 4 and FIG. 5. The difference between the embodiment in FIG. 4 and the first embodiment in FIG. 1 is that the flexible elongate shaft 20 is omitted. In this case, an operator inserts the aspiration apparatus 200 directly into a lumen 60 of a hemodialysis catheter 100 as shown in FIG.5. Alternatively, the operator may insert the aspiration apparatus 200 directly into a lumen 70 of the hemodialysis catheter 100. The aspiration apparatus 200 may comprise a connector 23 adapted to connect a source of negative pressure 51 and a proximal end 62 of the lumen 60 of the hemodialysis catheter 100 as shown in FIG. 5. The operator then manipulates the operable member 17 to break the thrombus adjusting the source of negative pressure 51. The broken thrombus is sucked into the lumen 60 of the hemodialysis catheter 100 and removed. The operable member 17 may comprise a brush, an expandable wire bracket, or a retriever.

[0033] Another embodiment of an aspiration catheter 200 for removing thrombus from a hemodialysis catheter is shown in FIG. 6. The first difference between the embodiment in FIG. 6 and the second embodiment in FIG. 3 is that the flexible elongate shaft 20 may comprise a tapered tip 28. The tapered tip 28 may be angled, bent, or curved as well. The second difference between the embodiment in FIG. 6 and the second embodiment in FIG. 3 is that the operable device 30 is fixed to the tapered tip 28. Specifically, the operable member 17 is fixed to the tapered tip 28. The tapered tip 28 may be angled or curved to facilitate the engagement the operable member 17 with the hemodialysis catheter 100. The operable member 17 may comprise an expandable brush. The operable device may further comprise a hook 19. [0034] In all the above embodiments, the distal end of the operable device and/or the distal end of the flexible shaft of the aspiration catheter may have a nonlinear profile and/or a nonuniform cross section to facilitate engagement of the operable member 17 with the thrombus inside or outside of the hemodialysis catheter 100.

[0035] While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. The different aspects of the described embodiments may be combined together to improve the performance of the hemodialysis catheter. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Moreover, the advantages described herein are not necessarily the only advantages of the invention and it is not necessarily expected that every embodiment of the invention will achieve all of the advantaged described.

Claims

CLAIMS What is claimed is:

1. An aspiration catheter for removing thrombus from a hemodialysis catheter comprising: an elongate flexible shaft having a proximal end and a distal end; an operable device configured to engage and remove thrombus from the hemodialysis catheter; a source of negative pressure; and a connector adapted to connect the source of negative pressure to the proximal end of the elongate flexible shaft, wherein the source of negative pressure is configured to draw debris into the elongate flexible shaft of the aspiration catheter.

2. The aspiration catheter of claim 1 wherein the operable device is disposed at the distal end of the elongate flexible shaft configured for insertion through a lumen of the hemodialysis catheter, and wherein the operable device is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter,

3. The aspiration catheter of claim 2 wherein the operable device comprises one of a brush, a hook, a snare, and a retrieval basket disposed near the distal end configured to engage and remove thrombus from the lumen of the hemodialysis catheter.

4. The aspiration catheter of claim 3 wherein the operable device further comprises a rod attached to the one of the brush, the hook, the snare, and the retrieval basket, the rod being configured to be advanced through the elongate flexible shaft.

5. The aspiration catheter of claim 2 wherein the connector is a Toughy Borst connector.

6. The aspiration catheter of claim 2 wherein the connector comprises a sealable fitting.

7. The aspiration catheter of claim 2 wherein the operable device comprises an angled tip.

8. The aspiration catheter of claim 1 wherein the operable device extends and is fixed to the distal end of the aspiration catheter, wherein the aspiration catheter is configured for insertion through a lumen of the hemodialysis catheter, and wherein the operable device is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter.

9. The aspiration catheter of claim 8 wherein the operable device comprises one of a hook, a brush, a snare, and a retrieval basket disposed near the distal end and configured to engage and remove thrombus from the lumen of the hemodialysis catheter.

10. The aspiration catheter of claim 8 wherein the connector comprises a sealable fitting.

11. The aspiration catheter of claim 8 wherein the distal end of the elongate flexible shaft comprises a tapered tip, and wherein the operable device is fixed to the tapered tip of the elongate flexible shaft.

12. The aspiration catheter of claim 1 wherein the operable device is configured for insertion through a lumen of the hemodialysis catheter, and wherein the operable device is capable of being extended beyond a distal end of the lumen of the hemodialysis catheter.

13. The aspiration apparatus of claim 12 wherein the operable device comprises one of a brush, a hook, a snare, and a retrieval basket disposed near the distal end and configured to engage and remove thrombus from the lumen of the hemodialysis catheter.

14. The aspiration apparatus of claim 12 wherein the operable device comprises an angled tip at the distal end of the elongate flexible shaft.