Endoscopic carpal tunnel release

For ECTR or any carpal tunnel release surgery while there are many different blades and techniques the primary goal is to release the transverse carpal ligament (TCL) that overlies and compresses the median nerve within the carpal tunnel. It is this compression on the median nerve that leads to the characteristic 'pins and needles' paresthesia in the thumb, index, long and ring fingers. The primary benefit of endoscopic releases versus traditional open carpal tunnel release is often perceived to be the smaller incision size. ECTR incisions are commonly less than 1 cm (0.39 in) compared to a 2–4 in (51–102 mm) longitudinal incision with a traditional carpal tunnel release. However, the incision size is not the only factor that differentiates the two methods. The principle behind the endoscopic release is that the Palmar aponeurosis, a thick tough layer of tissue that lines the palm, is not divided with endoscopic methods. In addition, the endoscopic methods offer less dissection and interruption of tissue planes than the open methods because the endoscopic methods do not divide the subcutaneous tissues or the palmar fascia to the same degree as the open method does.[3] Thus, a more rapid recovery is generally touted with ECTR as the normal skin above the TCL is not incised. Surgery, either open or endoscopic is a way to treat Carpal Tunnel Syndrome. A meta-analysis supports the conclusion that endoscopic carpal tunnel release is favored over the open carpal tunnel release in terms of a reduction in scar tenderness and increase in grip and pinch strength at a 12-week follow-up [4]

The use of an endoscope to release the carpal tunnel was first described in 1989 by Okutsu et al.[5] Here a flexible clear plastic tube was used with a standard endoscope to identify the transverse carpal ligament and release it with a retrograde knife.

It has been shown in recent literature that there is a learning curve for a hand surgeon who begins to use an endoscopic technique to release the transverse carpal ligament.[7] However this same recent study also showed no significant morbidity associated with the endoscopic method.

Brown et al. conducted a prospective, randomized, multi-center study and found no significant differences between the two groups with regard to secondary quantitative outcome measurements.[8] However, the open technique resulted in more tenderness of the scar than the endoscopic method. A prospective randomized study done in 2002 by Trumble revealed that good clinical outcomes and patient satisfaction are achieved more quickly with the endoscopic method. Single-portal endoscopic surgery is a safe and effective method of treating carpal tunnel syndrome. There was no significant difference in the rate of complications or the cost of surgery between the two groups. However, the open technique caused greater scar tenderness during the first three months after surgery, and a longer time before the patients could return to work.[9] In addition, in patients without workers compensation issues, the single-incision endoscopic carpal tunnel release led to less palmar tenderness and a quicker return to work compared to the two-incision endoscopic carpal tunnel release [10]

Despite these views, some surgeons have suggested that in their own hands endoscopic carpal tunnel release has been associated with a higher incidence of median nerve injury, and for this reason, it has been abandoned at several centers in the United States. At the 2007 meeting of the American Society for Surgery of the Hand, a former advocate of endoscopic carpal tunnel release, Thomas J. Fischer, MD, retracted his advocacy of the technique, based on his own personal assessment that the benefit of the procedure (slightly faster recovery) did not outweigh the risk of injury to the median nerve. Contrary to this one or any one opinion of any individual surgeon it has been shown that while there is a learning curve for a hand surgeon who begins to use an endoscopic technique to release the transverse carpal ligament no significant safety issues or morbidity associated with the endoscopic method exist.[11] The use of endoscopic carpal tunnel release has continued to spread around the world and clinical and nerve electrophysiological states are significantly improved at the long-term follow-up after endoscopic carpal tunnel release.[12] A meta-analysis supports the conclusion that endoscopic carpal tunnel release is favored over the open carpal tunnel release in terms of a reduction in scar tenderness and increase in grip and pinch strength at a 12-week follow-up[13][14]

A study comparing the open method and endoscopic method resulted in a longer interval until the patient could return to work (median, twenty-eight days, compared with fourteen days for the open-release and endoscopic-release groups).[15]

A recent study regarding outcome of Endoscopic carpal tunnel release has shown that clinical and nerve electrophysiological states are significantly improved at the long-term follow-up after endoscopic carpal tunnel release.[16] Further evidence supports that carpal tunnel release done endoscopically offers benefits in the early post operative period beyond that of open carpal tunnel syndrome. This came in the form of level 1 evidence as a meta-analysis that supports the conclusion that endoscopic carpal tunnel release is favored over the open carpal tunnel release in terms of a reduction in scar tenderness and increase in grip and pinch strength at a 12-week follow-up [17]

• Chow, J (1989). "Endoscopic release of the carpal ligament: A new technique for carpal tunnel syndrome". Arthroscopy. 5 (1): 19–24. doi:10.1016/0749-8063(89)90085-6. PMID 2706047.
• Chow, J. C. Y. (1990). A Breakthrough in Carpal Tunnel Release. Andover, Massachusates: Smith & Nephew Dyonics.
• 3M Company (1990). The Agee surgical technique and user's guide: Agee Inside Job™ carpal tunnel release system. St. Paul, Minnesota: 3M Orthopedic Products Division.
• Tsai, T; Tsuruta, T; Syed, S; Kimura, H (1995). "A new technique for endoscopic carpal tunnel decompression". The Journal of Hand Surgery. 20 (4): 465–9. doi:10.1016/S0266-7681(05)80154-8. PMID 7594984. S2CID 42282449.
• US patent 5282816, Miller, Brent W.; Resnick, Charles T., "Apparatus for subligamentous endoscopic transverse carpal ligament release", issued February 1, 1994
• Brown, RA; Gelberman, RH; Seiler Jg, 3rd; Abrahamsson, SO; Weiland, AJ; Urbaniak, JR; Schoenfeld, DA; Furcolo, D (1993). "Carpal tunnel release. A prospective, randomized assessment of open and endoscopic methods". The Journal of Bone and Joint Surgery. American Volume. 75 (9): 1265–75. doi:10.2106/00004623-199309000-00002. PMID 8408148.