Method and apparatus for thread transection of a ligament

Abstract

A method and apparatus for transecting soft tissue, such as a ligament, and more particularly, the transverse carpal ligament. A retrieval tool and a threadlike cutting element enable the method to performed in a minimally invasive manner. The cutting element is routed into position about the target ligament such that the cutting element both enters and exits the body from the same side of the ligament. The smooth exterior surface of the cutting element serves to provide for a kerf-less cut.

What is claimed is: 
     
         1 . A system for transecting a ligament within a body, comprising:
 a flexible cutting element having a smooth surface;   a substantially rigid, needle-like retrieval tool of a length sufficient to extend from a first location transversely adjacent to such ligament to a second location transversely adjacent to such ligament and opposite to such first location, and of a configuration for releasably engaging said cutting element and maintaining engagement therewith under a tensile load; and   an imaging device capable of visualizing said retrieval tool relative to a ligament.   
     
     
         2 . The system of  claim 1 , wherein said cutting element has a diameter less than 0.5 mm . 
     
     
         3 . The system of  claim 1 , wherein said cutting element has a zero bend radius. 
     
     
         4 . The system of  claim 1 , wherein said cutting element has a bend radius less than about half the thickness of said ligament. 
     
     
         5 . The system of  claim 1 , wherein said cutting element has a tensile strength of greater than 500 MPa. 
     
     
         6 . The system of  claim 1 , wherein said retrieval tool has a hook-shaped void formed therein near its distal end. 
     
     
         7 . The system of  claim 1 , wherein said imaging device comprises an ultrasound imaging device. 
     
     
         8 . The system of  claim 1 , further comprising a thin-walled, flexible protective tube dimensioned to receive said cutting element and formed of a material selected to allow movement of said cutting element thereto without being cut thereby. 
     
     
         9 . The system of  claim 1 , wherein said retrieval tool has a sharp distal tip. 
     
     
         10 . The system of  claim 1 , wherein said retrieval tool comprises a hypodermic needle and distal portion configured for engaging said cutting element, wherein said distal portion is attachable to said hypodermic needle. 
     
     
         11 . The system of  claim 1 , wherein said distal portion has a blunt distal tip.