At 1 year 7 patients (78%) had a reproducible increase in bladder pressure with stimulation of the dermatome. Two patients were able to stop catheterization and all safely stopped antimuscarinics. No patient achieved complete urinary continence. The majority of subjects reported improved bowel function. One patient was continent of stool at baseline and 4 were continent at 1 year. Of the patients 89% had variable weakness of lower extremity muscle group at 1 month. One child had persistent foot drop and the remainder returned to baseline by 12 months.
The authors present the first North American experience with lumbar to sacral nerve rerouting for patients with spina bifida. The results from this study and previous animal and clinical studies by Xiao clearly demonstrate that nerve rerouting produces a somatic-autonomic or cutaneous/bladder reflex with stimulation of the lower extremity dermatome. What is also clear is that the clinical benefit of the procedure is not at all similar to previous reports.Although the authors did an excellent job of following the patients and characterizing their changes, the results are hard to validate without a control population going through the same rigorous surveillance regimen. In particular the improved bowel continence and minimal changes in bladder compliance may not be statistically significant. The fact that most patients were still on clean intermittent catheterization and none achieved complete urinary continence is troubling in light of the report of 87% success with 110 children with spina bifida presented by Xiao. One has to wonder if most of these children are not voiding volitionally or using the newly developed cutaneous reflex, and how much reinnervation has a role in this surgery. Is it possible that unilateral denervation of the S3 ventral motor nerve produced improved compliance and continence, as previously reported in numerous clinical series?I congratulate the authors for taking on this challenge. I hope this study leads to a rebirth or refocus regarding neurosurgical treatments of neuropathic bowel and bladder. I strongly agree with the authors that this procedure should remain on a research protocol only.
One of the most curious findings is the discrepancy between urodynamic data and subjective voiding. One patient exhibited a decrease in capacity and an absence of reflex arc, and yet he subjectively reported improved bladder and bowel function! I could not help but speculate that his voiding after the procedure could simply be the bladder emptying via intra-abdominal pressure generation against an open bladder neck, given his preoperative stress incontinence. Xiao reported that more than 87% of 110 patients gained sensation and continence within 1 year (reference 7 in article). In comparison, the current patients undergoing the identical procedure with the help of Xiao himself only showed a modest improvement in objective urodynamic studies and subjective reporting. Unless the innovators provide a sound argument and data for the validity of the procedure, there is a great danger of its improper and rapid adaptation by patients and the medical community at large.