Comparison of Carpal Tunnel Release Methods and Complications

Carpal tunnel release is one of the most common hand surgeries performed at the North Florida/South Georgia Veterans Health System (NFSGVHS). Depending on surgeon experience and comfort level, surgeries are performed through either the traditional open method or the endoscopic method, single or double port (Figures 1 and 2). The advantage of the endoscopic method is faster recovery and return to work; however, the endoscopic method requires more expensive equipment and a steeper learning curve for surgeons. Complications are uncommon but can create unsatisfactory patient experiences because of costly lost workdays and long travel distances to the medical facility.

The purpose of this study was to compare the endoscopic method with the open carpal tunnel release method to determine whether there was an increased complication risk. Researchers anticipated that this information would help surgeons better inform patients of operative risks and prompt changes in NFSGVHS treatment plans to improve the quality of veteran care.

Methods

An Institutional Review Board- approved (#647-2011) retrospective review was done of patients who had carpal tunnel surgery performed by the NFSGVHS plastic surgery service from January 1, 2005, to December 31, 2010. Surgeries included in the review took place at the Malcom Randall VAMC in Gainesville and at the Lake City VAMC, both in Florida. Most of the surgeries included in the study were performed by a resident or fellow under the supervision of an attending physician. Eight different attending surgeons staffed the operations. Seven were board-certified or board-eligible plastic surgeons, 2 had advanced hand fellowship training, and 1 was a general surgeon with hand fellowship training. All hand fellowship-trained surgeons were in their first year of practice at the time of the study.

Only primary carpal tunnel releases were included in the study. Exclusion criteria included patients who were operated on by a service section other than the plastic surgery service (orthopedics or neurosurgery) and hands on which other procedures were performed during the same operation. Charts were reviewed for up to 1 year post surgery. Complications that required intervention were recorded. Researchers did not include pillar tenderness or an increase in occupational therapy visits as complications, due to the wide variety of patient tolerance to postoperative pain and varying motivation to return to work and daily routine.

Methods of release were endoscopic, open, or endoscopic converted to open. All but 6 of the completed endoscopic surgeries were performed using the double port Chow technique. The other 6 endoscopic surgeries were performed using the single port Agee technique at the distal wrist crease. There were 3 endoscopic converted to open cases that were performed using a single port, proximally-based technique in the midpalm. This method was abandoned after 3 unsuccessful endoscopic attempts, 1 resulting in digital nerve injury despite interactive cadaver labs prior to operative experience.

Endoscopic surgeries converted to open were recorded as open surgeries, because the patients had the full invasive experience. Researchers used the chi-square test and P value < .05 to compare the different methods of carpal tunnel release with identified complications.

Results and Complications

A total of 584 hands belonging to 452 patients were included in the study. Patients included 395 men and 57 women aged from 33 to 91 years. There were 271 endoscopic releases, 228 open releases, and 85 endoscopic converted to open releases. The NFSGVHS conversion rate was 23.7%. Complications in the converted cases (n = 4) were included in the open release results.

There were 40 complications in 38 hands. The overall complication rate was 6.5%. Complications noted were tendonitis presenting as De Quervain disease or trigger finger (9 endoscopic surgeries; 6 open surgeries), infection (2 endoscopic surgeries; 6 open surgeries), wound dehiscence (5 open surgeries), nerve injury (1 open surgery), respiratory distress (1 endoscopic), complex regional pain syndrome (1 open surgery), and scheduled returns to the operating room (OR) for recurrent, ongoing, or worsening symptoms (5 endoscopic surgeries; 5 open surgeries). Complications with an n > 1 were evaluated for statistical significance with P value < .05 (Table 1).

The NFSGVHS study had 10 patients return to the OR for open exploration (Table 2). Nine of these patients went back to the OR based on symptoms consistent with nerve conduction studies that had deteriorated compared with their preoperative studies. One endoscopic case was brought back to the OR for a suspected nerve injury without nerve conduction studies. Findings during reoperation included scar adhesions, incomplete release of ligaments, digital nerve injury, and negative explorations.

Two hypothenar fat transfers were performed to prevent scar adhesions in cases that had originally been open releases.¹ Two of the open cases were endoscopic converted to open cases. One went back to the OR with a suspected nerve injury. Dense adhesions and an injured common digital nerve were identified and repaired. The second converted case that went back to the OR had a suspected, but unconfirmed, nerve injury to the motor branch. The diagnosis and treatment were delayed for more than a year due to the patient having other pressing medical and family concerns. An exploration found significant scar adhesions, and an opponensplasty was performed.