Clinical Neurophysiologist Northwell Health Hauppauge, New York, United States
Introduction: Intraoperative bulbocavernosus reflex (BCR) can evaluate sacral nervous system function. There is paucity in literature surrounding the use of BCR monitoring and no alarm criterion has been established. Herein we describe our initial experience adding novel recordings of the external urethral sphincter reflex (EUSR) to monitor contemporaneously with the BCR.
Methods: We prospectively collected neuromonitoring data for spinal surgeries involving the sacral spinal cord and/or sacral nerve roots adding the EUSR to our pelvic floor neuromonitoring paradigm. Operative and neuromonitoring reports were reviewed. Surgeries without tumor pathology were excluded. Comparative analysis was performed in each patient and across the cohort.
Results: A total of 18 procedures on 14 patients met the inclusion criteria (8 Female/6 male). These included sacrectomy (n14), intradural tumor removal (n3), and epidural tumor removal (n1). Reliable BCR recordings were obtained in 14 (78%) procedures, whereas reliable EUSR recordings were obtained in 13(72%) procedures. The BCR and EUSR were obtained contemporaneously in 67% (n12) of procedures. Two procedures had simultaneous attenuation of the BCR and EUSR recording amplitudes after planned ligation of the sacral roots. Both patients awoke with expected bowel and bladder dysfunction. Two other patients exhibited isolated EUSR amplitude deterioration with no deviation of the BCR recordings. One of these patients exhibits persistent bladder incontinence at 4-months post-op, while the other had their Foley catheter removed post-op day 4 and was discharged without the need for further catheterization. All other patients with stable BCR and EUSR remain neuro-urologically intact.
Conclusion : The EUSR is a novel technique which can be applied in surgeries when bowel/bladder function, are at risk. Our group succeeded in obtaining stable, non-habituating EUSR signals in order to bring redundancy and add complementarity to our previously established pelvic floor neuromonitoring paradigm. Further research is needed with a larger sample size to establish efficacy and statistical significance.
