Intraoperative bulbocavernosus reflex monitoring for predicting postoperative voiding dysfunction in patients with distal intraspinal tumors.

OBJECTIVE

To investigate the predictive value of intraoperative bulbocavernosus reflex (BCR) monitoring for voiding dysfunction post-operatively in patients with distal intraspinal tumors and to determine an appropriate timing for postoperative follow-up assessment.

METHODS

Patients with distal intraspinal tumors who underwent surgery with BCR monitoring were collected. Patients were classified into BCR absent and present groups according to the monitoring responses at the end of surgery. Voiding function was evaluated at 1 week, 2 months, 4 months, and 6 months after surgery.

RESULTS

A total of 52 patients were included. There were 30 (57.7 %) males and the mean age was (48.6 ± 17.2) years. Forty-nine (94.2 %) patients were adult. BCR was preserved in 50 (96.2 %) patients and completely disappeared in 2 cases at the end of the surgery. The sensitivity of intraoperative BCR loss for worsened voiding were 20.0 %, 33.3 %, 66.7 %, and 100.0 % at 1 week, 2 months, 4 months, and 6 months post-operatively respectively. The specificity was all 100.0 % at the four follow-ups. Preoperative voiding difficulty was more common in patients suffering from worsened voiding than those maintained at 1 week post-operatively (P < 0.05).

CONCLUSIONS

Intraoperative BCR monitoring is a reliable technique to predict the postoperative voiding dysfunction in patients with distal intraspinal tumors. Preservation of the BCR is a robust indication for favorable postoperative urinary function as time goes on and 6-month post-operatively may be an optimal timing for functional assessment with high sensitivity and specificity. Preoperative voiding symptoms may be a risk factor for voiding difficulty at early stage after surgery.