Tissue slitting methods and systems

Abstract

Methods and systems for separating an object, such as a lead, from formed tissue are provided. Specifically, a tissue slitting device is configured to engage patient formed tissue at a slitting engagement point. While the object is subjected to a first traction force, the tissue slitting device is caused to move further into the engaged tissue and slit the tissue past the point of engagement. The slitting device causes the tissue to separate along an axial direction of the length of the formed tissue and releases at least some of the force containing the object. The methods and systems are well suited for use in cardiac pacing or defibrillator lead explant procedures.

What is claimed is: 
     
         1 . A tissue slitting apparatus comprising:
 a shaft, wherein the shaft is flexible, the shaft having a proximal and a distal end, and wherein the shaft includes an inner lumen running from the proximal to the distal end to receive at least one of an implanted object and mechanical traction device; and   a fluid conveying device disposed adjacent to the distal end of the shaft, wherein the fluid conveying device is configured to separate a tissue growth along a side and a length of the tissue growth using a pressurized fluid.   
     
     
         2 . The tissue slitting apparatus of  claim 1 , wherein the fluid conveying device further comprises:
 at least one fluid channel; and   at least one port, operatively connected to the at least one fluid channel, wherein the at least one port is configured to direct the pressurized fluid in a direction toward a section of the tissue growth.   
     
     
         3 . The tissue slitting apparatus of  claim 2 , wherein the at least one port further comprises a nozzle disposed at a distal end of the at least one port, the nozzle having an inlet side and an outlet side, and wherein the nozzle is configured to receive a fluid at a first pressure at the inlet side and increase the pressure of the fluid to a second pressure at the outlet side. 
     
     
         4 . The tissue slitting apparatus of  claim 2 , wherein the pressurized fluid comprises at least one of saline, sodium chloride (“NaCl”), and magnesium chloride (“MgCl”). 
     
     
         5 . The tissue slitting apparatus of  claim 2 , wherein the at least one port is disposed at an angle to the inner lumen of the tissue slitting apparatus such that pressurized fluid is diverted to a point of contact between the tissue growth and the implanted object. 
     
     
         6 . The tissue slitting apparatus of  claim 2 , wherein the at least one fluid channel is configured to convey fluid from the proximal to the distal end of the shaft. 
     
     
         7 . The tissue slitting apparatus of  claim 2 , further comprising an array of ports operatively connected to the at least one fluid channel and disposed adjacent to the distal end of the shaft. 
     
     
         8 . The tissue slitting apparatus of  claim 2 , wherein the fluid conveying device is disposed at an angle to an axis running along the inner lumen of the shaft. 
     
     
         9 . The tissue slitting apparatus of  claim 2 , wherein the fluid conveying device is disposed substantially parallel to an axis running along the inner lumen of the shaft and proximally tangential to a circumference of the inner lumen. 
     
     
         10 . A method, the method comprising:
 separating only a portion of a tissue growth at least substantially surrounding an implanted object in a patient; and   thereafter removing the implanted object from the tissue growth.   
     
     
         11 . The method of  claim 10 , wherein the separating and thereafter removing steps comprise the sub-steps:
 attaching a mechanical traction device to the implanted object;   inserting the mechanical fraction device into a tissue slitting apparatus, the tissue slitting apparatus further comprising:
 a flexible shaft, wherein the flexible shaft has a proximal and a distal end; 
 an internal lumen, wherein the internal lumen is configured to allow at least one of an implanted object and mechanical traction device to pass therethrough; and 
 a fluid conveying device operatively connected with the distal end of the flexible shaft; 
   applying a mechanical traction force to the mechanical traction device;   indexing the tissue slitting apparatus to an engagement area of the tissue growth in contact with the implanted object;   moving the fluid conveying device adjacent to the tissue growth; and   activating the fluid conveying device, such that a section of the tissue growth is ablated and separated from the implanted object at least at the engagement area with pressurized fluid directed via the fluid conveying device.   
     
     
         12 . The method of  claim 11 , wherein the fluid conveying device separates a first, but not a second, portion of the tissue growth around a circumference of the implanted object and wherein prior to indexing the tissue slitting apparatus to the engagement area, the method further comprises:
 orienting the fluid conveying device to separate tissue along a free length of the tissue growth where the tissue growth is free from attachment to a portion of vasculature of the patient.   
     
     
         13 . The method of  claim 12 , wherein orienting the fluid conveying device further comprises:
 aligning the fluid conveying device along an area of the free length of the tissue growth wherein a thickness of the first section of the tissue growth surrounding the implanted object is less than a thickness of a second section of the tissue growth surrounding the implanted object, and wherein the second length of the tissue growth is attached to the vasculature of the patient.   
     
     
         14 . The method of  claim 11 , further comprising:
 determining whether the tissue growth is completely separated along a length of the tissue growth surrounding the implanted object; and   moving the fluid conveying device further into the tissue growth to ablate and separate any tissue growth determined to remain along the length of the tissue growth surrounding the implanted object.   
     
     
         15 . The method of  claim 10 , wherein the tissue growth is subjected to a slitting action about a partial periphery of an internal diameter of the tissue growth adjacent to and at least substantially surrounding the implanted object at any point along the implanted object. 
     
     
         16 . A system to remove tissue from a vascular lumen, the system comprising:
 a lead locking device for locking onto a lead within the vascular lumen;   a flexible shaft comprising
 a proximal end; 
 a distal end comprising a fluid conveying device capable of ablating tissue; and 
 an internal lumen configured to allow at least one lead to pass therethrough, wherein the lead locking device holds the lead while the fluid conveying device ablates tissue surrounding at least a portion of the lead. 
   
     
     
         17 . The system according to  claim 16 , wherein the fluid conveying device further comprises:
 at least one fluid channel; and   at least one port, operatively connected to the at least one fluid channel, wherein the at least one port is configured to direct the pressurized fluid in a direction toward a section of the tissue growth.   
     
     
         18 . The system according to  claim 17 , wherein the at least one port further comprises a nozzle disposed at a distal end of the at least one port, the nozzle having an inlet side and an outlet side, and wherein the nozzle is configured to receive a fluid at a first pressure at the inlet side and increase the pressure of the fluid to a second pressure at the outlet side. 
     
     
         19 . The system according to  claim 16 , wherein the lead locking device is configured to lock onto an internal structure of the lead. 
     
     
         20 . The system according to  claim 16 , wherein the lead locking device is configured to lock onto an external structure of the lead.