Predictive value of intraoperative bulbocavernosus reflex during untethering surgery for post-operative voiding function

Objective To evaluate the clinical significance of intraoperative bulbocavernosus reflex (BCR) during untethering surgery in predicting post-operative voiding function. Methods We conducted a retrospective review of pediatric patients who underwent untethering surgery with available intraoperative baseline BCR. BCR response during surgery was classified into loss or maintenance. Post-operative voiding function was determined as worsened or maintained based on history, postvoid residual urine measurement, and urodynamic study (UDS). Data regarding demographics, diagnosis, pre-operative voiding difficulty, re-untethering, syrinx, and abnormalities in electromyography were collected for analysis. Results We included 106 patients, with a mean age of 3.3 years, and 49 patients were male. BCR was lost in 15 patients during surgery and voiding function worsened in 14 patients after surgery. Lumbosacral lipoma was the most common diagnosis, and 16 patients were diagnosed with lipomyelomeningocele (LMMC). The sensitivity and specificity of intraoperative BCR for post-operative worsening of voiding function were 35.7%, and 88.5% at 6 months, respectively. The diagnosis of LMMC was statistically significant in a logistic regression analysis. The specificity of BCR at 6 months in patients with diagnosis other than LMMC was 93.4%, and intraoperative BCR was significant in a logistic regression analysis. Conclusions Intraoperative BCR during untethering could predict bladder function 6 months post-operatively with high specificity (88.5%), particularly in cases other than LMMC (93.4%), indicating that voiding function deterioration will not occur if intraoperative BCR is preserved. Significance Intraoperative BCR during untethering surgery is a useful tool to predict post-operative voiding outcome.