Transferring fascicles of obturator nerve restoring vesical branch of pelvic nerve to treat the micturition function of patients caused by sacral plexus injury

Abstract

Objective To explore the feasibility of transferring of the obturator nerve onto the vesical branch of pelvic nerve with direct anastomosis, in order to restore the automatic micturition function of patients with bilateral lower sacral plexus injury (S2-S4). Methods Data of five patients (4 males and 1 female) with bilateral lower sacral plexus injury who had surgery from May to July 2018 were retrospectively analyzed. The average age was 26 years old (range, 23-30 years old) and the average delay from injury to operation was 10.2 months (range, 7-14 months). Three patients suffered with fell off injury and two patients had car accident injury. All patients presented with continence and the urodynamics revealed flaccid neuropathic bladder with neurogenic adynamia of detrusor muscle. The vesical branch of pelvic nerve was dissected between the bladder and the ureter where it entered the bladder neck from backward to forward almost vertically. The obturator nerve was dissected along the pelvic sidewall, and the comparable bundle branch of obturator nerve was transferred onto the vesical branch of pelvic nerve with direct anastomosis. The diameter and freed length of pelvic nerve and the fascicles of the obturator nerve were measured intraoperatively, and the cutaneous sensation of medial thigh and the muscle strength of hip adduction were evaluated postoperatively. Results The surgery was performed through the traditional abdominal paramedian approach in 3 patients and through the pararectus approach in 2 patients. The vesical branch of pelvic nerve in all five patients could be revealed clearly and there was enough operative space for nerve transferring. The surgery was successful in all five patients without any complication. The donor nerves were anterior branch of obturator nerve in 2 patients, posterior branch of obturator nerve in 1 patient, 2/3 fascicles of anterior branch of obturator nerve in 1 patient and 2/3 fascicles of posterior branch of obturator nerve in 1 patient. The average length and diameter of freed fascicles of obturator nerve were 2.28 cm (range, 1.9-2.6 cm) and 1.36 mm (range, 1.2-1.5 mm). The average length and diameter of pelvic nerve were 2.46 cm (range, 2.2-2.7 cm) and 1.2 mm (range, 1.1-1.3 mm). The vesical branch of pelvic nerve and the bundle branch of the obturator never were comparable and anastomosed free of tension. The sensation of medial aspect of thigh was almost normal and the muscle strength of hip adduction was M4 postoperatively. Conclusion The vesical branch of pelvic nerve can be well exposed via pararectus approach. Transferring of the fascicles of obturator nerve onto the vesical branch of pelvic nerve is feasible and safe. Key words: Obturator Nerve; Splanchnic nerves; Lumbosacral plexus; Nerve transfer