Urological Outcome of the Xiao Procedure in Children with Myelomeningocele and Lipomyelomeningocele Undergoing Spinal Cord Detethering

Purpose Although previous studies have revealed high success rates (70% to 85%) after an intradural somatic-to-autonomic nerve transfer procedure in children with spinal dysraphism, no study has had a control group or blinded observers. We report a rigorously designed study to investigate the effectiveness of the Xiao procedure. Materials and Methods Children with neurogenic bladder dysfunction related to myelomeningocele or lipomyelomeningocele who required spinal cord detethering were randomized to 2 groups at surgery, with half undergoing only spinal cord detethering and half undergoing the Xiao procedure in addition to detethering. Double-blind evaluations were performed at regular intervals during the 3-year followup. Results A total of 10 patients underwent spinal cord detethering only and 10 underwent detethering plus the Xiao procedure. The Xiao procedure did not result in voluntary voiding or continence in any patient, but patients undergoing spinal cord detethering plus the Xiao procedure were more likely to have greater improvements in total bladder capacity, bladder overactivity and overall quality of life than those who underwent detethering only. By the end of the study no participant or evaluator was able to accurately predict to which group the patients had been assigned. Conclusions The results of this randomized controlled trial are in agreement with recently published similarly poor results of the Xiao procedure in patients with spinal cord injury. Improvements in bladder parameters observed in this study may be related to sacral nerve root section, a necessary portion of the Xiao procedure, instead of reinnervation. Confirmatory animal studies are recommended before further clinical trials of the Xiao procedure are performed in humans.