Intraoperative bulbocavernosus reflex monitoring in posterior lumbar fusion surgery.

Objective: To assess the utility of intraoperative bulbocavernosus reflex (BCR) monitoring in posterior lumbar fusion surgery.

Methods: We retrospectively evaluated 153 patients undergoing posterior lumbar fusion with intraoperative BCR monitoring. Voiding function was assessed at discharge and two follow-ups.

Results: BCR was preserved in 151 patients and completely disappeared in two patients at the end of surgery. For patients in whom BCR was preserved, voiding difficulties at discharge and 1-month and 6-month follow-ups were noted in 16 (10.6%), 9 (6.0%), and 0 (0.0%) patients, respectively. However, patients with BCR loss experienced voiding difficulties at all three time-points. Statistical analysis showed a significant difference in voiding between those with preserved and disappeared BCRs at 6 months postoperatively. BCR disappeared during surgery but recovered before the end of surgery in six patients. Among these patients, one experienced transient voiding difficulties postoperatively but with good recovery. However, the other five patients did not experience postoperative voiding difficulties.

Conclusions: BCR had low sensitivity for voiding dysfunction at discharge, but had high accuracy at 6-month follow-up examinations. BCR loss was associated with new voiding dysfunction.

Significance: Intraoperative BCR monitoring is a potentially useful tool for enhancing safety during posterior lumbar fusion by predicting postoperative voiding dysfunction.