Clinical study of reconstructed bladder innervation below the level of spinal cord injury to produce urination by Achilles tendon–to-bladder reflex contractions

Abstract

Object Neurogenic bladder dysfunction following spinal cord injury (SCI) is a major medical and social problem for which there is no ideal treatment strategy. In the present study, the authors analyze the effectiveness of neurogenic bladder reinnervation in patients with SCIs by using Achilles tendon reflexes below the paraplegic level. Methods Spinal root anastomoses were performed in 12 paraplegic patients with hyperreflexic neurogenic bladder and detrusor external sphincter dyssynergia (DESD) caused by complete suprasacral SCI, in an attempt to reinnervate the bladder. The surgery anastomosed the unilateral proximal end of the S-1 ventral root and the distal end of the S-2 and/or S-3 ventral roots to build the Achilles tendon–to-bladder reflex, while the S-1 dorsal root was kept intact as the trigger for micturition after axonal regeneration. All patients underwent urodynamic evaluation before surgery and at follow-up. Results The mean follow-up duration was 3 years. Of the 12 patients, 9 (75%) regained satisfactory bladder control within 6 to 12 months after ventral root microanastomosis. In these 9 patients, urodynamic studies revealed a change from detrusor hyperreflexia with DESD and high detrusor pressure to almost normal storage and synergic voiding without DESD. The average bladder capacity increased from 258 ± 33 ml to 350 ± 49 ml, residual urine decreased from 214 ± 36 ml to 45 ± 11 ml, and urinary infections were not observed. Patients with impaired renal function experienced a full recovery. Three patients failed to show any improvement after the operation. Conclusions These results suggest the effectiveness of bladder innervation below the level of SCI to produce urination by Achilles tendon–to-bladder reflex contractions, and might therefore provide a new clinical approach to reconstructing spasmodic bladder urination function.