When CMS added CPT 29848 (wrist endoscopy) to the ASC Medicare List in July 2003, it made endoscopic carpal tunnel release a Group 9 procedure - $1,339 by today's unadjusted rate. Open carpal tunnel release (CPT 64721) is a Group 2 procedure, reimbursed at $446, nearly three times less than the endoscopic procedure. It was around this time that more surgeons began discovering the benefits of minimally invasive surgical techniques for carpal tunnel release. The closed-wrist procedure is said to be quicker and cleaner - albeit trickier - to perform, and you can perform it in a procedure room rather than an OR.

Medicare is slated to scale back what it pays for CPT 29848 if'the proposed Medicare Payment Modernization Act is passed. After a four-year implementation of these reimbursement changes, the new fee is anticipated to be $1,197, making endoscopic carpal tunnel release comparable to other endoscopic procedures of the knee (29881) or shoulder (29823), says Judie English, the vice president of business operations for Surgery Center Billing, LLC.

Minimally invasive technique
The endoscopic procedure, developed in the 1990s, uses one or two incisions to let surgeons scope the median nerve, the nine tendons and tenosynovium that pass through the semi-circle formed by carpal bones on three sides. The surgeon then uses a blade to divide the ligament, creating space and relieving pressure on the nerve. Since endoscopic CTR doesn't involve slicing through the muscle and flesh in the open wrist, there's less chance of infection, and patients recover full function more quickly, say proponents.

Both open as well as endoscopic procedures accomplish the same thing; however, endoscopic carpal tunnel release requires only a small incision (1.5 cm to 2 cm) in the wrist and an endoscope to visualize the carpal ligament, which the surgeon cuts with a small blade under direct visualization. With the open carpal tunnel procedures, a relatively long incision is required - usually 4 cm to 8 cm - to release the carpal tunnel. By using an endoscopic technique for surgery, it is believed that the skin and soft tissue of the palm can be preserved and therefore causing less post-operative pain and promoting more rapid recovery.

But the procedure involves specialized training, so it hasn't caught on everywhere. "There's widespread confusion about the pros and cons of both open and endoscopic procedures," says Michael G. Brown, MD, founder of the Hand Center in Houston, who developed and patented the Brown Procedure for endoscopic CTR. "As with anything new, including many medical advances over the century, education is warranted."

With his technique, says Dr. Brown, the overlying palmaris brevis muscle, palmar fascia, thenar and hypothenar muscle fibers, fat and nerve fibers contained within it, and the skin remain intact. "In the open carpal tunnel release procedure, all of these layers are divided, as the hand is filleted open from the skin all the way down to the median nerve," says Dr. Brown. "The result is scar-tissue formation from the skin all the way down to the carpal tunnel."

Patients can often return to work the next day after his endoscopic technique "if they are engaged in sedentary-type work activities," says Dr. Brown. "They can write and type with the operated hand. They are simply a bit slower. At 10 days, the sutures are removed and the dressings removed and there are no restrictions whatsoever."

For more on Dr. Brown's technique, see "Key Points to Remember."

Better or not?
Gabrielle White, RN, director of the Orthopedic Surgery Center of Orange County in Newport Beach, Calif., says endoscopic carpal tunnel release takes about the same amount of time as an open procedure - 30 minutes to induce MAC anesthesia, 10 minutes for the procedure and 45 minutes for recovery.

"I've seen it done in six minutes," says Faris Zureikat, the administrator at the North Texas Surgery Center in Dallas. His center uses the 3M Agee Carpal Tunnel Release System.

Some centers do endoscopic release in procedure rooms, while others keep it in the OR. In terms of scheduling, Ms. White says it's a good idea to line up your CTR cases in the same room. Do all the left-hand procedures first, for example, then all the rights. "Moving the equipment takes more time than the actual surgery," she says. At a center he once ran, David Kelso, RN, PhD, had a surgeon who performed closed-wrist procedures in continuously running rooms. "You need to have a surgeon who knows how to work two rooms," says Dr. Kelso, now the director of St. James Healthcare, an acute care hospital in Butte, Mont.

Why not more?
As appealing as the endoscopic procedure seems, not everyone has abandoned the open procedure, based on the interviews we conducted. Of Ms. White's four hand surgeons, three do the closed procedure and one, the youngest doctor, prefers the open procedure. "It's all a comfort thing," she says. "Maybe the open procedure gives you more control - seeing it retracted versus seeing it on screen."

At Mr. Zureikat's center, eight physicians are credentialed to perform carpal tunnel release, and only one regularly performs the endoscopic procedure. That, he says, could mean there's a shortage of physicians who can do the procedure.

Dr. Kelso had one surgeon who was very efficient in doing endoscopic CTR, but that surgeon is serving in Iraq, so the center is now doing only the open-wrist procedure.

"It is a fact of life that time is money and endoscopic CTR is a much faster procedure at our facility, whereas open procedure would easily run a multiple of that number," says Mr. Zureikat. "In our area, Medicare reimbursement for endoscopic CTR is more than double that of open CTR."

Not everyone is enamored of the endoscopic process, even if they're familiar with it. "The learning curve is pretty steep," says Michael Kalson, MD, who practices at the Academy Orthopedic Ambulatory Surgery Center in Cumming, Ga.

Dr. Kalson says he feels the open-wrist procedure is safer, quicker and has just as good outcomes. Open-wrist patients can usually resume some work the day after the procedure and are back to full strength when the stitches come out 10 days later, says Dr. Kalson. "The incision is not that big to begin with," he says.

Karen Bennett, RN, ONC, the administrator of Academy Orthopedics, says surgeons used to do the endoscopic procedure at her center but became wary after reports of complications with it and stopped.

Mr. Zureikat says there's some chance for complications by surgeons who haven't become completely proficient in the process. Surgeons need to really see the nerve on the monitor. "If you don't see the nerve, you don't cut," he says.

Dr. Kelso thinks that the endoscopic procedure could catch on the way other changes have occurred in the ambulatory surgery industry. "People used to go to the hospital for cataracts," he says. "Now they have it done in an office."