The Case for Endoscopic Carpal Tunnel Release

Patients who experience numbness and pain in their hands — the telltale symptoms of carpal tunnel syndrome — can opt to have the condition treated with open surgery performed through an inch-long incision made on the palm of the hand or endoscopically through a 2 cm incision made at the base of the wrist. Both techniques are effective and reliable, but the endoscopic approach results in less post-op pain and leads to faster recoveries, according to Brad Hill, MD, a hand and upper extremity surgeon at Vanderbilt University Medical Center in Nashville, Tenn.

Dr. Hill says the open and endoscopic techniques show similar outcomes at six months after surgery. However, he adds, the endoscopic approach has been shown to improve patient satisfaction, especially among patients with bilateral disease, who Dr. Hill believes are the best candidates for the minimally invasive procedure. “If I were to perform open surgery on both hands, the patient would have difficulty bathing, brushing their teeth and using the toilet,” he explains. “Recovery is much smoother following endoscopic surgery.”

The carpal tunnel is comprised of bones along the bottom and sides and the transverse carpal ligament along the top. It’s filled with tendons that control the movement of the fingers and the median nerve, which runs from the forearm to the palm of the hand. Carpal tunnel syndrome is caused by swelling of the tendons within the tunnel, which can grow larger through overuse and compress the median nerve. Compression of the nerve leads to hand weakness, loss of feeling or significant pain that can impede normal function — the symptoms that send patients to seek help.

Treatment with anti-inflammatories is intended to shrink the swelling of the tendons and relieve pressure on the median nerve. The treatment is a temporary solution, however, and doesn’t have a high success rate in terms of sustained relief from the symptoms of carpal tunnel syndrome, according to Charles S. Day, MD, MBA, executive vice chair and chief of hand and upper extremity surgery at Henry Ford Hospital in Detroit.

Carpal tunnel release surgery, a more permanent fix to relieving pressure on the median nerve, involves cutting the transverse carpal ligament to expand the space that the enlarged tendons occupy. “The result is a carpal tunnel with a 50% larger diameter,” says Dr. Day.

Open carpal tunnel release involves splitting the ligament from above. Endoscopic surgery involves making a small incision at the base of the inside of the wrist where the skin is less sensitive, which limits the pain patients experience.

Surgeons who use the endoscopic approach enter one end of the tunnel and deploy a knife that cuts the ligament under direct visualization. The endoscopic approach is performed with light sedation — or no sedation at all — and local anesthesia, making it an appropriate treatment in office-based procedure areas.

Dr. Day says the data is mixed on which approach is the best option for patients, but he believes endoscopic surgery is safer and faster — the direct and magnified views of the ligament let him perform more precise cuts — than the open technique. He concedes the treatment of choice for surgeons is based on how they were trained and which one they’re comfortable performing, with older surgeons tending to prefer the open technique and younger surgeons gravitating toward the endoscopic approach.

Dr. Hill says he can perform endoscopic carpal tunnel release in less than 10 minutes and points out that the technique lowers the risk of wound healing complications and results in improved recoveries. His patients often return to work and life activities within a week, much sooner than they would after open surgery, which increases their satisfaction with the treatment.

“Endoscopic carpal tunnel release lets patients recover faster and in less pain, factors that make it the better treatment option,” says Dr. Hill. “I find increasing its use comes down to educating patients about the latest treatment options and presenting the best available outcomes data.”

Dr. Day’s recent research, which was published in the March 2021 issue of the Journal of Occupational and Environmental Medicine, revealed carpal tunnel syndrome isn’t a condition suffered exclusively by office workers. He found rates among individuals in construction and manufacturing industries — in which high-force hammering, extreme wrist motions and the use of vibrating equipment are common — outpace rates among office workers.

“This study is an important reminder that carpal tunnel is a primary contributor to hand and upper extremity pain in both clerical and manufacturing workplaces, and that ergonomic conditions for workers in both industries should be equally considered,” says Dr. Day. He also points out that diabetes, thyroid dysfunction, rheumatoid arthritis, fluid retention during pregnancy and history of wrist fractures or trauma are conditions that can cause carpal tunnel syndrome.

Patients are realizing that ignoring the symptoms and putting off treatment can cause muscles in the wrist to atrophy and irreversible nerve damage. Splinting and physical therapy can improve the symptoms, but patients often seek a more permanent fix to the problem.

Each week, Dr. Day sees 10 to 15 patients who are suffering from carpal tunnel syndrome and performs four to five endoscopic surgeries to treat the condition. He says about half of his patients opt to undergo wide awake surgery, part of a growing trend among hand specialists. Patients receive a shot of local anesthetic at the incision site and are in and out of the procedure room in minutes.

“Expanding the treatment to more outpatient locations allows us to offer it to patients who qualify for the procedure while preserving hospital resources for those patients who require acute care,” says Dr. Day. OSM

Note: This three-part article series is supported by Hand Biomechanics Lab.