Background/Purpose: The gold standard for definitive treatment of severe carpal tunnel syndrome is surgery, either endoscopic or open.  Unfortunately, both surgical procedures have pitfalls including relatively long term recovery, complications, and lack of success, which often is due to incomplete transection of the TCL.

The Guo TCTR technique is an innovative method for releasing the carpal tunnel.  Performed using local anesthetic with ultrasound needle guidance, a loop of proprietary metal-impregnated cutting thread is looped around the TCL.  This is accomplished by inserting an 18 gauge spinal needle just proximal to the superficial palmar arterial arch (SPA) and guiding it proximally, superficial to the SPA, then deep, to pierce the proximal part of the palmar aponeurosis and run on the deep surface of the TCL.  This needle is ultrasonographically guided proximally, until it surfaces through the skin at the exit point, 1 cm proximal to the proximal wrist crease, in the Nakamichi safe zone, between the median nerve and the ulnar artery.  The thread is passed through this needle and the needle is removed.  A second spinal needle is then passed through the same entrance and exit points, except that this 2nd needle is guided along the superficial surface of the TCL.  When the 2^ndneedle is in place, the proximal end of the thread is passed through it, and the needle is removed.  This results in the thread looped around the TCL with both ends of the thread protruding through the skin at the initial entry point.  The operator grasps the two ends of the thread, and uses a to-and-fro sawing motion.   The thread cuts through the TCL.

Methods: To determine whether this method performed a complete TCL transection, we performed eight carpal tunnel release procedures in eight cadaver wrists.  After each case, surgical dissection was done to directly view the results.  Dissection of the first case performed with the entry point at the typical site of carpal tunnel release (trapezium/hamate line) showed incomplete distal release of the TCL and the proximal palmar aponeurosis, creating an incomplete release.  The subsequent seven procedures used a more distal needle insertion point, and we added initial hydrodissection of the proximal palmar aponeurosis with a 27 gauge needle to move the “duck’s beak” of the distal TCL edge to a more volar position.  This permitted more exact placement of the thread loop to encompass the entirety of the distal TCL. 

Results: All seven of the procedures using the revised more distal approach resulted in total TCL release from the proximal to the distal TCL border.  No damage to neural or vascular structures occurred. Previous clinical experience with this method has shown excellent results with minimal morbidity. (Guo D, Tang Y, Ji Y, Sun T, Guo J, Guo D. A non-scalpel technique for minimally invasive surgery: percutaneously looped thread transection of the transverse carpal ligament. Hand. 2015; 10:40-48).  Conclusion: The advantages of this procedure are the relative lack of invasiveness, use of local anesthetic only, shorter recuperation, decreased likelihood of complications, and greater assurance of complete transection of the TCL.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/thread-carpal-tunnel-release-tctr-completely-divides-the-transverse-carpal-ligament-tcl-as-well-as-open-and-endoscopic-surgery-a-cadaver-study/