Pre- and postoperative Guyon's canal pressure change in endoscopic carpal tunnel release: correlation with transient...

Perioperative Guyon's canal and carpal canal pressure in one-forearm portal endoscopic carpal tunnel release surgery were measured in resting position and during active power gripping in 66 hands. This was done using the continuous infusion technique with a local anaesthetic and without pneumatic tourniquet. Immediate mean postoperative Guyon's canal and carpal canal pressure decreased in both measurements. During active power gripping, postoperative Guyon's canal pressure was less than 40 mmHg in 61 hands, however, this increased to over 40 mmHg in five hands. In these five hands, Guyon's canal syndrome did not develop. Guyon's canal and carpal canal pressures were only correlated during postoperative active power gripping. It remains unclear whether immediate postoperative Guyon's canal pressure correlates with higher pressures a few days later as reported in cases of transient postoperative Guyon's canal syndrome.