Methods and devices for in situ formed nerve cap with rapid release

Abstract

Disclosed are methods, devices and materials for the in situ formation of an implant for treating a nerve. A treatment site on a nerve is positioned within a cavity defined by a form. A transformable media is introduced into the form cavity to surround the treatment site. The media is permitted to undergo a transformation from a first, relatively flowable state to a second, relatively non flowable state to form a protective barrier surrounding the treatment site. A hydrophilic characteristic of the media cooperates with a hydrophobic characteristic of the surface of the cavity to facilitate a rapid release of the implant from the cavity following the transformation. The implant may be a growth inhibiting nerve cap to inhibit neuroma formation following planned or traumatic nerve injury, a growth permissive conduit for facilitating reconnection of a severed nerve, or an anchor for stabilizing a pain management electrode with respect to a nerve. Access to the nerve treatment site may be open surgical or percutaneous.

1 . A method of in situ formation of an implant, comprising the steps of:
 identifying a nerve;   positioning the nerve in a cavity defined by a form;   introducing media into the cavity to surround the nerve; and   permitting the media to undergo a transformation from a first, relatively flowable state to a second, relatively non flowable state to form a protective barrier surrounding the nerve;   wherein a hydrophilic characteristic of the media cooperates with a hydrophobic characteristic of the cavity to facilitate a rapid release of the implant from the cavity following the transformation.   
     
     
         2 . The method of in situ formation as in  claim 1 , comprising positioning a severed end of a nerve into the cavity, and permitting the media to undergo a transformation state to form a protective barrier surrounding the severed end of the nerve. 
     
     
         3 . The method of in situ formation as in  claim 1 , wherein the implant can be removed from the cavity by a pull force of no more than about 10 N, applied for no more than about 5 seconds. 
     
     
         4 . The method of in situ formation as in  claim 1 , wherein the implant can be removed from the cavity by a pull force of no more than about 5 N. 
     
     
         5 . The method of in situ formation as in  claim 1 , wherein the implant can be removed from the cavity by a pull force of no more than about 2 N applied for no more than about 2 seconds. 
     
     
         6 . The method of in situ formation as in  claim 1 , wherein the implant can be removed from the cavity within about 2 seconds, without disrupting attachment between the implant and the nerve. 
     
     
         7 . The method of in situ formation as in  claim 1 , wherein the in situ formation occurs through chemical or photo crosslinking. 
     
     
         8 . The method of in situ formation as in  claim 1 , wherein the introducing media step includes introducing a first volume of media, and following transformation of the first volume, introducing a second volume of media. 
     
     
         9 . A method of in situ formation of an implant, comprising the steps of:
 identifying an implant formation site;   positioning a form having an implant cavity at the site;   introducing media into the cavity to form an implant precursor; and   permitting the media to undergo a transformation from a first, relatively flowable state to a second, relatively non flowable state to form the implant;   wherein a hydrophilic characteristic of the media cooperates with a hydrophobic characteristic of the cavity to facilitate a rapid release of the implant from the cavity following the transformation.   
     
     
         10 . The method of in situ formation as in  claim 9 , wherein the implant is a nerve cap for inhibiting neuroma formation around a severed nerve end. 
     
     
         11 . The method of in situ formation as in  claim 9 , wherein the implant is a nerve conduit for guiding growth of a nerve. 
     
     
         12 . The method of in situ formation as in  claim 9 , wherein the implant is a nerve wrap for preventing scar tissue-related nerve compression and nerve tethering. 
     
     
         13 . The method of in situ formation as in  claim 9 , wherein the implant reduces the incidence or persistence of chronic pain. 
     
     
         14 . The method of in situ formation as in  claim 9 , wherein the implant is a tissue bulking implant. 
     
     
         15 . The method of in situ formation as in  claim 9 , wherein the implant is a vascular occlusion device. 
     
     
         16 . The method of in situ formation as in  claim 9 , wherein the implant is a tendon repair device. 
     
     
         17 . A method of in situ formation of a nerve cap, comprising the steps of:
 identifying a severed end of a nerve;   positioning the severed end into a cavity defined by a form;   introducing media into the cavity to surround the severed end; and   permitting the media to undergo a transformation from a first, relatively flowable state to a second, relatively non flowable state to form a protective barrier surrounding the severed nerve end;   wherein a hydrophilic characteristic of the media cooperates with a hydrophobic characteristic of the cavity to facilitate a rapid release of the nerve cap from the cavity following the transformation.   
     
     
         18 . A method of in situ formation of a nerve cap as in  claim 17 , further comprising the step of removing the form. 
     
     
         19 . A method of in situ formation of a nerve cap as in  claim 17 , comprising identifying a surgically or traumatically severed nerve. 
     
     
         20 . A method of in situ formation of a nerve cap as in  claim 17 , wherein the form comprises a nerve guide, and said positioning step comprises positioning the nerve such that the nerve guide maintains the severed end within the cavity spaced apart from a sidewall of the form. 
     
     
         21 .- 99 . (canceled)