Endoscopic Carpal Tunnel Release Without Invading the Tunnel: A New Transretinacular Technique.

Established endoscopic carpal tunnel release (ECTR) techniques carry a not entirely eludible risk of iatrogenic complications, mainly because of incomplete view of the cutting blade and intraoperative pressure increase inside the carpal tunnel (CT). We describe a novel single-portal ECTR method, conceived to reduce these risks, by optimizing visual control and avoiding dilatation of the CT. After incising the well exposed proximal third of the transverse carpal ligament (TCL), transection of the remainder is completed using a pediatric urethrotome. This small caliber instrument is moved in the plane of the TCL, without invading the tunnel, and provides detailed view of the TCL and any crossing anatomical structures at any given moment. We present the technique and the results of a retrospective case series of 33 patients with CT syndrome who underwent the procedure, after failing to respond to conservative treatment. Because of improved view and the avoidance of intraoperative pressure trauma to structures passing through the CT, the described approach may contribute to prevent iatrogenic complications and represent a valid improvement over conventional ECTR procedures.