There is no strong evidence supporting the need for replacement of standard open carpal tunnel release by existing alternative surgical procedures for the treatment of carpal tunnel syndrome. The decision to apply endoscopic carpal tunnel release instead of open carpal tunnel release seems to be guided by the surgeon's and patient's preferences 1).
Several studies have shown less postoperative pain and improvement in grip and pinch strength with the endoscopic technique. The goal of a study was to prospectively examine outcomes, patient satisfaction, and complications after both ECTR and OCTR in the opposite hands of the same patient.
This was a prospective study in which patients with bilateral carpal tunnel syndrome underwent surgical release with both techniques, with initial operative approach randomized in the more symptomatic hand. Demographic data and functional outcomes were recorded, including the pain score, 2-point discrimination, Semmes-Weinstein monofilament testing, thenar strength testing, grip strength, carpal tunnel syndrome functional status score, carpal tunnel syndrome symptom severity score, and overall satisfaction.
Thirty patients completed the study; there were no significant differences in any measure at any of the postoperative time points. Symptom severity and functional status scores were not significantly different between groups at any evaluation. Subjectively, 24 of 30 patients did state they preferred the ECTR, mostly citing less pain as their primary reason, although pain scores were not significantly different. Differences in overall satisfaction were also not significant.
Both techniques are well tolerated with no differences in outcomes. With the added cost and equipment associated with ECTR, and no added benefit, the usefulness of ECTR is questionable 2).
63 patients were allocated to endoscopic surgery and 65 patients to open surgery, with no withdrawals or dropouts. Pain in the scar or proximal palm was less prevalent or severe after endoscopic surgery than after open surgery but the differences were generally small. At three months, pain in the scar or palm was reported by 33 patients (52%) in the endoscopic group and 53 patients (82%) in the open group (number needed to treat 3.4, 95% confidence interval 2.3 to 7.7) and the mean score difference for severity of pain in scar or palm and limitation of activity was 13.3 (5.3 to 21.3). No differences between the groups were found in the other outcomes. The median length of work absence after surgery was 28 days in both groups. Quality of life measures improved substantially.
In carpal tunnel syndrome, endoscopic surgery was associated with less postoperative pain than open surgery, but the small size of the benefit and similarity in other outcomes make its cost effectiveness uncertain 3).
A 64-year-old woman undergone endoscopic carpal tunnel release (ECTR) for right carpal tunnel syndrome 16 months earlier. Thereafter, she reported persistent dysesthesia in the thumb and index finger, developed burning pain in the middle and ring finger, paleness, coldness, and edema of the hand, a decreased range in hand motion, and a painful subcutaneous nodule just distal to the portal in the forearm. Based on physical, radiological, and electrophysiological studies, the diagnosis was incomplete carpal tunnel release associated with complex regional pain syndrome (CRPS). At open revision surgery, the carpal tunnel was released completely and the nodule was removed. Symptoms other than hypesthesia in the middle and ring fingers improved. Pathologically, the nodule was an amputation neuroma. Her CRPS was attributed to ECTR complications; i.e., persistence of median nerve compression and the formation of an amputation neuroma in the palmar cutaneous branch of the ulnar nerve at the portal. Surgeons must be aware that ECTR, a less invasive technique, may result in serious complications including CRPS 4).
Aslani H, Zafarani Z, Najafi A, Alizadeh K, Farjad R, Ghahremani S, Mosavvari M, Lahiji FA. Comparison of morphologic consequences of open and endoscopic carpal tunnel release. Clin Neurol Neurosurg. 2014 May;120:96-8. doi: 10.1016/j.clineuro.2014.02.025. Epub 2014 Mar 7. PubMed PMID: 24731585.
Ryu SJ, Kim IS. Pseudoaneurysm of ulnar artery after endoscopic carpal tunnel release. J Korean Neurosurg Soc. 2010 Oct;48(4):380-2. doi: 10.3340/jkns.2010.48.4.380. Epub 2010 Oct 30. PubMed PMID: 21113371; PubMed Central PMCID: PMC2982922.
Law TY, Rosas S, Hubbard ZS, Chieng LO, Chim HW. Trends in open and endoscopic carpal tunnel release utilization in the Medicare patient population. J Surg Res. 2017 Jun 15;214:9-13. doi: 10.1016/j.jss.2017.02.055. Epub 2017 Mar 6. PubMed PMID: 28624065.