|Editor: Alan R. Cohen, MD||Spring 2009|
At the conclusion of the recent First World Congress on Spina Bifida Research and Care in Orlando, Fla., the Spina Bifida Association hosted a two-day postgraduate course on the promising but controversial new surgical procedure known as the lower urinary tract refunctionalization by somatic/autonomic nerve root transposition. This procedure was pioneered by Chuan-Guo Xiao, MD, from the Union Hospital of Tongji Medical College in China. Dr. Xiao is a urologist who has dedicated the last two decades of his career to the development of these techniques.
The procedure, commonly called the Xiao procedure, involves the surgical transposition of functional lumbar ventral roots to sacral roots. Typically the L5 ventral root is partially or completely divided and rerouted/anastamosed to the S3 root or complex of sacral roots containing S3 and S4. The rationale for the procedure centers on the spinal reflex-arc and on the capability of somatic motor axons to regenerate into and replace preganglionic axons. Clinically vigorous stimulation within the dermatome of the transposed lumbar root initiates a spinal reflex that results in bladder contraction. Experimental work done by Xiao and colleagues in the late 1980s and early 1990s in rat, cat and dog models demonstrated histological evidence of bladder reinnervation. Between 1995 and 2002, 86 patients with spinal cord injuries were treated, and the reported success rate was 80 percent. The National Institutes of Health sponsored a trial for 40 spinal-cord-injured patients at New York University in 2003. An 80 percent response rate was reported. Between 2000 and 2003, 40 patients with spina bifida were treated and an 85 percent effectiveness rate was observed. Between 2003 and the time of the meeting presentation, approximately 1,300 children had undergone the Xiao procedure in China. Only 400 patients were available for follow-up due to cultural and geographic issues, but Dr. Xiao and his team observed an 87 percent rate of effectiveness.
As a result of these reported outcomes there has been great excitement among spina bifida patients and their families about the procedure. Other urologists and neurosurgeons throughout the world have become sufficiently interested in learning the procedure, and Dr. Xiao has lectured and operated extensively. The Orlando meeting was the first time that he taught the surgical technique in a postgraduate course in North America. More than 75 attendees were present and were evenly divided between urologists and neurosurgeons.
The Xiao procedure has been performed in the United States by a group from William Beaumont Hospital in Royal Oak, Mich., led by urologist Ken Peters. Dr. Peters traveled to China to learn the procedure and invited Dr. Xiao to be present at the initial surgeries in Michigan. Financing was achieved through philanthropic benefactors, and follow-up has been comprehensive and essentially uniform. Dr. Peters also presented at the Orlando postgraduate course. A total of nine patients were operated upon and their outcomes were reviewed with up to a three-year follow-up. Dr. Peters reported that two patients are no longer requiring catheterization and that seven of nine patients have some measureable return of reflex. Bowel function improved more quickly and more extensively than bladder function. Eight-to-nine patients had bilateral leg weakness initially, yet their weakness improved back to baseline such that only one patient has residual weakness. One patient has foot drop.
In addition to the Beaumont group, several groups in North America have learned the procedure and prepared a protocol for treatment. These include groups in Tampa, Fla., led by Gerald Tuite, MD, and in Atlanta, Ga., led by urologist Edwin Smith. Dr. Tuite also traveled to China to learn the surgical technique directly from Dr. Xiao. Immediately before the meeting Dr. Tuite invited Dr. Xiao to Tampa, and eight children were treated under the direction of both surgeons. Dr. Tuite’s partners and Tae Sung Park, MD, from Washington University/St. Louis Children’s Hospital also observed or participated in the surgeries. The Atlanta group has approved a protocol and has institutional review board approval, but it has not yet operated upon any patients.
Extensive discussion and rigorous debate ensued and closed out the first day of the postgraduate course. The second day was dedicated to discussions regarding how best to initiate trials in the U.S. and elsewhere. The Beaumont, Atlanta and Tampa groups all presented proposed protocols. The Tampa protocol is unique in that it proposes performing the procedure only in the context of detethering a tethered spinal cord. Significant debate about protocols ensued. There was a strong consensus of opinion that the procedure should only be done in the setting of a cooperative, properly constructed (good design, sufficient power, etc.), organized multicenter clinical trial. There was uniformity of opinion across disciplines that children with spina bifida and society at large are poorly served when multiple centers undertake small, independent studies, and that such studies are counterproductive to proper assessment of the technique. The Beaumont, Atlanta and Tampa groups all agreed to halt further surgery until a unified neurosurgery/urology research design could be developed.
A task force headed by Jeffrey Blount, MD, and Dr. Tuite was formed that will coordinate the development of an organized approach in neurosurgery. There will be a meeting of all interested groups at the upcoming AANS Annual Meeting to further these discussions and move forward with the development of protocols. The meeting time and location will be forthcoming.
Jeffrey P. Blount, MD, University of Alabama at Birmingham, and Gerald Tuite, MD, University of South Florida, Tampa.