Objective: To evaluate bladder and urethral sphincter reinnervation mechanisms during long-term follow-up in patients with lower motor neuron neurogenic bladder following neurological surgical injury.
Methods: A urodynamic study was conducted in 30 patients (21 male and 9 female; mean age 53.4 years) with lower motor neuron neurogenic bladder dysfunction arising from neurological injury sustained during surgery. The protocol included cystometry and periurethral electromyography (EMG) at 3, 6, 9, 12 months and once a year for 7 years, and videocystography at 3, 12 months and once a year for 7 years. Functional parasympathetic (detrusor) reinnervation criteria were cystometric. Functional sympathetic (bladder neck) reinnervation criteria were cystographic. Functional pudendal (periurethral sphincter) reinnervation criteria were electromyographic (increase of polyphasic and long amplitude and/or long time potentials).
Results: Detrusor reinnervation was demonstrated in 6 male patients (20%) with an average period of 44.6 months. Pudendal reinnervation was demonstrated in 17 patients (77.2%) with an average period of 17.6 months. EMG potentials were polyphasic in 17 cases and long amplitude/long time potentials in 3 cases. Sympathetic reinnervation was demonstrated in one patient (16.6%) at 60 months.
Conclusions: Functional pudendal reinnervation of the periurethral sphincter was more frequent and was demonstrated earlier than reinnervation in vegetative elements (parasympathetic and sympathetic). Parasympathetic reinnervation had long-term therapeutic implications. Ongoing urodynamic assessment in patients with lower motor neuron neurogenic bladder following abdominoperineal resection or intervertebral disc prolapse surgery is warranted. Sympathetic reinnervation was scanty and was demonstrated later in relation to distal postganglionic fibers.