Is pelvic plexus nerve documentation feasible during robotic assisted laparoscopic ureteral reimplantation with extravesical approach?

Purpose: Urinary retention is a known complication of using an extravesical approach for ureteral reimplantation, especially in bilateral cases. The etiology may be secondary damage to pelvic nerves during ureteral dissection. Recent literature suggests that it is possible to visually identify these nerves during a robotic assisted laparoscopic approach. We performed an exploratory study to identify and document them in pediatric patients by means of electrophysiologic recordings.

Material And Methods: Seven consecutive patients undergoing robotic assisted laparoscopic ureteral reimplantation with extravesical approach were prospectively enrolled in the study. Following dissection of the ureter below the level of vas deferens in male and the uterine artery in female, staying close to the adventitia and approaching the ureterovesical junction, the fibers as described in human cadaveric studies were identified dorsomedial to the ureter and preserved. Stimulating and recording electrodes were passed through to record post-synaptic compound muscle action potentials of the bladder.

Results: Even though the nerve fibers were visually identified, we were unable to consistently and reproducibly record compound muscle action potentials after stimulation of putative pelvic plexus fibers at the distal ureter, despite modulation in stimulation intensity, pulse characteristics, signal recording sensitivity and stimulator probe variation.

Conclusions: In this pilot study, the inconsistent findings raise questions about the exact location of the neurovascular bundle, nature of bladder smooth muscle electrophysiology and the appropriate methodology of evaluation. This may provide a reason to reexamine the intraoperatively expected location of pelvic plexus nerve fibers.