Retractor endoscopic techniques in the treatment of entrapment peripheral neuropathies

With increasing awareness for minimally invasive approaches, endoscopic techniques for peripheral nerve decompression are becoming increasingly popular. The first endoscopic approach to release a pinched nerve was for carpal tunnel release through a single entry port, whereby the compressed canal was dilated with bougies and an endoscope introduced into this canal to transect the transverse carpal ligament. Since most of the manipulations with the blunt bougie in this technique were done in a blind fashion, there was a lurking potential for iatrogenic nerve injury using the bougie technique. Thus the retractor-integrated endoscopic technique was developed. In this technique, the retractor bearing the endoscope is introduced into a plane above the compressing ligaments and the nerve proper and a bird's eye perspective of the anatomical site is gained. Owing to the simplicity of the technique, the retractor-endoscope was used to decompress any nerve at any site in the body: furthermore it was employed for harvesting nerves, vessels and tendons for transplantation. In this paper, we describe the various endoscopic techniques used for decompression in peripheral nerve entrapment syndromes and provide a comprehensive and comparative metaanalysis of the techniques.