Bladder leak point pressure: the measure for sphincterotomy success in spinal cord injured patients with external detrusor-sphincter dyssynergia.

PURPOSE: Transurethral resection of the external sphincter in patients with spinal cord injury and detrusor-external sphincter dyssynergia has high failure and reoperation rates. Retrospectively we examined elevated bladder leak point pressure after transurethral resection of the external sphincter as an indicator of failure.

MATERIALS AND METHODS: A total of 55 spinal cord injury patients (mean age 50 years) underwent 1 or more sphincter resections, most recently a mean of 11 years ago. We reviewed the most recent urodynamic studies for bladder leak point pressure, bladder compliance and persisting external detrusor-sphincter dyssynergia. Each patient was assessed for the presence of an indwelling catheter, upper tract damage, stones, bacteriuria, autonomic dysreflexia and vesicoureteral reflux. The incidence of each of these urodynamic and clinical parameters among patients with bladder leak point pressure less than 40 cm. water was compared to the incidence among those with bladder leak point pressure greater than 40 cm. water.

RESULTS: Patients with bladder leak point pressure greater than 40 cm. water had a significantly higher incidence of upper tract damage (p = 0.021) and persisting external detrusor-sphincter dyssynergia (p = 0.00008). The incidence of an indwelling catheter was no different between patients with bladder leak point pressure less than and greater than 40 cm. water.

CONCLUSIONS: Bladder leak point pressure greater than 40 cm. water is a valid indicator of failure of transurethral resection of the external sphincter since there is a significantly higher incidence of upper tract damage and persisting external detrusor-sphincter dyssynergia in these patients. Patients with favorable urodynamic parameters after transurethral resection of the external sphincter but with indwelling catheters were poorly selected for this procedure. Furthermore, those without an indwelling catheter after transurethral resection of the external sphincter may still have adverse urodynamic parameters and are at significant risk for upper tract damage.