Methods and systems for restoring patency

Abstract

A method for maintaining patency in a duct or hollow vessel located within the body of a patient is described wherein the duct includes one or more obstructions. The method comprises the steps of introducing a device into the duct, the device comprising a catheter having a distal and a proximal end, wherein the distal end includes a distal tip portion and wherein the distal tip portion comprises at least one energy delivery member; locating the device within the duct at a position proximal to the obstruction; delivering energy to the duct and any surrounding tissue via the at least one energy delivery member for a specified time period, so that the obstruction is removed from the duct; and withdrawing the device from the duct. It is optional to subsequently place a device such as a stent at the therapy site in order to further maintain long term patency of the duct. It is also optional to apply a dilation force to the duct or hollow vessel after the energy delivery phase. Systems are also described for performing the methods of the disclosure.

1 . A method for maintaining patency in a duct located within the body of a patient, wherein the duct includes one or more obstructions, the method comprising the steps of:
 (a) introducing a device into the duct, the device comprising a catheter having a distal and a proximal end, wherein the distal end includes a distal tip portion and wherein the distal tip portion comprises at least one energy delivery member;   (b) locating the device within the duct at a position proximal to the obstruction;   (c) delivering energy to the duct and any surrounding tissue via the at least one energy delivery member for a specified time period, so that the obstruction is removed from the duct; and   (d) withdrawing the device from the duct.   
     
     
         2 . The method of  claim 1 , wherein the distal tip portion of the device comprises a plurality of energy delivery members. 
     
     
         3 . The method of  claim 1 , wherein the energy delivery member comprises a radiofrequency (RF) electrode. 
     
     
         4 . The method of  claim 1 , wherein the energy delivery member comprises at least two RF electrodes arranged in a bipolar configuration. 
     
     
         5 . The method of  claim 4 , wherein the at least two RF electrodes are spaced at least about 1 mm and at most about 15 mm apart. 
     
     
         6 . The method of  claim 4 , wherein the at least two RF electrodes are spaced no more than about 8 mm apart. 
     
     
         7 . The method of  claim 1 , wherein the device further comprises a sensor for measuring impedance in the tissue whilst energy is delivered to the duct and surrounding tissues in step (c). 
     
     
         8 . The method of  claim 1 , wherein the device further comprises a temperature sensor within the distal tip portion. 
     
     
         9 . The method of  claim 1 , further comprising the additional step of:
 (e) inserting a stent into the duct at the location proximal to the obstruction where the energy was delivered so as to maintain patency in the duct.   
     
     
         10 . The method of  claim 1 , wherein the position proximal to the obstruction in step (e) already comprises a pre-located stent that has become obstructed subsequent to placement in the duct. 
     
     
         11 . The method of  claim 1 , further comprising the additional step of:
 (e) applying a dilation force to the duct so as to maintain patency.   
     
     
         12 . The method of  claim 11 , wherein the dilation force is applied via use of a balloon dilation catheter. 
     
     
         13 . The method of  claim 11 , wherein the dilation force is applied via use of a tethered SEMS catheter. 
     
     
         14 . The method of  claim 1 , wherein the duct is a duct comprised within the biliary tree. 
     
     
         15 . The method of  claim 1 , wherein the duct is a fallopian tube. 
     
     
         16 . The method of  claim 1 , wherein the duct is a bronchiole. 
     
     
         17 . The method of  claim 1 , wherein the duct is the oesophagus. 
     
     
         18 . The method of  claim 1 , wherein the duct is part of the urinary tract. 
     
     
         19 . The method of  claim 1 , wherein the duct is part of the gastrointestinal tract, including the stomach. 
     
     
         20 . The method of  claim 1 , wherein the obstruction is tumor. 
     
     
         21 . The method of  claim 1 , wherein the obstruction comprises granulation tissue. 
     
     
         22 . The method of  claim 1 , wherein the obstruction comprises a thrombosis. 
     
     
         23 . The method of  claim 1 , wherein the obstructions comprises a stricture. 
     
     
         24 . The method of  claim 1 , wherein the obstruction comprises varices. 
     
     
         25 . The method of  claim 1 , wherein an energy level of no more than about 10 Watts is applied in step (c). 
     
     
         26 . The method of  claim 1 , wherein an energy level of no less than about 1 and no more than about 8 Watts is applied in step (c). 
     
     
         27 . The method of  claim 1 , wherein the specified time period for delivery of energy is no less than about 10 and no more than about 300 seconds. 
     
     
         28 . The method of  claim 1 , wherein the specified time period for delivery of energy is no more than about 2 minutes (120 seconds). 
     
     
         29 . A method for maintaining the method comprising the steps of:
 (a) introducing a first device into the duct, the first device comprising a catheter having a distal and a proximal end, wherein the distal end includes a distal tip portion and wherein the distal tip portion comprises at least one energy delivery member;   (b) locating the first device within the duct at a position proximal to an obstruction;   (c) delivering energy to the duct and any surrounding tissue via the at least one energy delivery member for a specified time period, so that the obstruction is removed from the duct, and then withdrawing the first device from the duct; and   (d) introducing a second device into the duct and locating the second device at the position proximal to the obstruction, wherein the second device is configured to apply a dilation force to the duct so as to maintain patency.   
     
     
         30 . The method of  claim 29 , wherein the second device comprises a balloon dilation catheter. 
     
     
         31 . The method of  claim 29 , wherein the second device comprises a stent delivery catheter. 
     
     
         32 . A system for restoring at least partial patency of a duct that has been subject to an occlusion, by increasing the luminal diameter of the duct, in a patient in need thereof, the system comprising:
 (i) a first device that comprises an endoscope, the endoscope comprising at least one central lumen extending along its length;   (ii) a second device that comprises a catheter, the catheter having a distal terminus and a region proximal to the distal terminus defining a distal tip region, the distal tip region comprising at least one RF electrode; and   (iii) a third device that comprises a stent delivery catheter and a stent that is to be delivered by the stent delivery catheter;   
       wherein the central lumen of the first device is configured so as to be of a diameter that is able to accommodate the second and third devices consecutively. 
     
     
         33 . The system of  claim 32 , wherein the central lumen is a biopsy channel. 
     
     
         34 . The system of  claim 32 , wherein the second device comprises a second lumen, and wherein the second lumen is configured in order that the second device can be mounted on a guide wire. 
     
     
         35 . The system of  claim 32 , wherein the second device comprises at least two RF electrodes in a bipolar configuration. 
     
     
         36 . The system of  claim 32 , wherein the at least two RF electrodes are spaced no more than about 8 mm apart. 
     
     
         37 . The system of  claim 32 , wherein the stent is a SEMS. 
     
     
         38 . A system for restoring at least partial patency of a duct that has been subject to an occlusion, by increasing the luminal diameter of the duct, in a patient in need thereof, the system comprising:
 (i) a first device that comprises an endoscope, the endoscope comprising at least one central lumen extending along its length;   (ii) a second device that comprises a catheter, the catheter having a distal terminus and a region proximal to the distal terminus defining a distal tip region, the distal tip region comprising at least one RF electrode; and   (iii) a third device that comprises a balloon dilation catheter;   
       wherein the central lumen of the first device is configured so as to be of a diameter that is able to accommodate the second and third devices consecutively. 
     
     
         39 . The system of  claim 38 , wherein the central lumen is a biopsy channel. 
     
     
         40 . The system of  claim 38 , wherein the second device comprises a second lumen, and wherein the second lumen is configured in order that the second device can be mounted on a guide wire. 
     
     
         41 . The system of  claim 38 , wherein the second device comprises at least two RF electrodes in a bipolar configuration. 
     
     
         42 . The system of  claim 38 , wherein the at least two RF electrodes are spaced no more than about 8 mm apart.