Endoscopic carpal tunnel release surgery: retrospective study of 390 consecutive cases.

Endoscopic carpal tunnel release (ECTR) surgery was developed by Okutsu and Chow in 1989. Many reports indicated that the endoscopic technique reduces postoperative morbidity with minimal incision, minimal pain and scarring, a shortened recovery period and high level of patient satisfaction. To evaluate these reports, a retrospective study was conducted with 390 procedures of two-portal Chow technique for idiopathic carpal tunnel syndrome. Follow-up was performed at 1, 3 and 6 months and overall results were backed up by telephone questionnaire (Health Outcomes Carpal Tunnel Questionnaire, Health Outcomes, Bloomington, MN, USA). Results were favourable in 98% and 2% unfavorable for persistent pain. Rate of satisfaction of the patients was 90%. Average time of patient's return to work was 20 days. Eleven procedures (2.8%) were converted to open release. There was one case (0.2%) of incompleted section of the perineurium due to failure of endoscopic visualization of the ligament. In this case the procedure was converted to open and was completed with perineurium sutura. In six cases (1.5%) there were injury to superficial palmar arch. During the follow-up period there were no recurrences and no re-exploration. The mean preoperatively obtainable distal motor latency (DML) and sensory conduction velocity (SCV) values were 6.7 m/s and 29.2 m/s, respectively. The mean DML and SVC values at final follow-up were 3.8 msec and 42.3 m/s, respectively. In conclusion, ECTR can be used in the carpal tunnel syndrome and is a reliable alternative to the open procedure with excellent self-report of patient satisfaction. Reduced recovery period with minimal tissue violation and incisional pain can be expected.