What happens to patients who have a first carpal tunnel surgery that isn’t entirely successful and then need a second (revision) procedure? Do they get better after the second surgery? How long do the results last? These are questions asked by researchers from the Division of Plastic and Reconstructive Surgery (Washington University in St. Louis School of Medicine). They conducted a retrospective study (taking a look back) of their patients over a 10 year period of time.
The patients were all adults who had their first carpal tunnel surgery before 2001. Each one was evaluated and placed in one of three groups. The groups included patients who had carpal tunnel symptoms that continued after the first surgery (group one), recurrent (group two: symptoms went away after surgery but then came back), or group three: new symptoms developed.
Medical records for each patient were reviewed and analyzed looking at a variety of information and factors. For example, they paid attention to the surgeon’s notes during the revision procedure. Two areas of interest from the notes were: 1) how the revision procedure was done and 2) what the surgeon found at the time of the surgery.
Information about the patients (e.g., age, work status, use of pain medications, results of electrodiagnostic tests) was collected and compared among the three groups. Clinical measures of grip and pinch strength were also measured, reported, and compared. Pain level and quality of life were also assessed. The authors provided all of this information for each group in a table for anyone interested in the exact details.
The groups divided up as follows: 42 per cent of the patients were in group one (persistent symptoms), 20 per cent had recurrent symptoms, and 37 per cent were in the new symptom group. When trying to find some differences among the three groups, the only significant factors were diabetes and longer time between first and second surgeries. These two variables were specific to the group with recurrent symptoms. New symptoms occurred more often in people who had an unintended nerve injury during the first surgery.
Clinically, everyone in all three groups did get pain relief with the revision surgery. Pain is not a key symptom in primary (first) episodes of carpal tunnel syndrome. Instead, numbness seems to be more common. The presence of scar tissue around the median nerve and nearby soft tissue structures may explain the pain feature. Loss of blood supply to those areas because of scar tissue pressing and blocking the nerve may be part of the picture. The senior surgeon on this project recommends entering the carpal tunnel away from the nerve to reduce the risk of complications from the second surgery.
Grip and pinch strength improved for the persistent and new group (as symptoms resolved) but not for the recurrent group. Those patients who used pain medication were more likely to experience no change (or even pain that got worse) after the second surgery. Overall, the long-term results were positive for all groups. This is good news for patients facing a second surgery for carpal tunnel syndrome when the first procedure was less than successful.