URINARY RETENTION AFTER HYSTERECTOMY: SACRAL NEUROMODULATION TO RESTORE MICTURITION

Abstract

A 44-year-old woman presented in nonobstructive urinary retention, which had developed after she had undergone hysterectomy for myoma of the uterus in January 1996. An indwelling catheter was placed for 1 week but overflow incontinence resumed after catheter removal. Residual urine was 600 to 1,000 ml. and the sensation of bladder filling was lost. Recurrent cystitis was accompanied by back and bladder pain when she tried to void. The frequency of bowel emptying, which had been every other day before hysterectomy, decreased to once a week and constipation developed. Excretory urography showed normal renal function without urinary obstruction. Neurological examination revealed irritation of the right plexus lumbosacralis with reduction of perianal and dermatomes Th12 and L1 sensitivity. Urodynamic evaluation demonstrated a bladder capacity of 1,000 ml. without bladder sensation or detrusor contraction, despite stimulation with rapid filling, coughing and intramuscular injection of 0.25 mg. carbachol. Maximal urethral closure pressure was 32 cm. water, and functional sphincteric length was 24 mm. Incontinence did not occur. Results of psychological evaluation were normal. Administration of 10 mg. bethanechol 3 times daily to strengthen the detrusor did not restore micturition, and the patient began clean intermittent self-catheterization. In June transurethral electrical bladder stimulation with continuous pulses of 10 Hz. for 1 hour at night, pulse duration 250 milliseconds and current less than 60 mA was performed for 4 weeks without success. Symptomatic cystitis recurred every 2 months for 2 years, despite antibiotics and careful clean intermittent catheterization. In October 1998 we tested percutaneous sacral neuromodulation. When the sacral spinal nerves S2, S3 and S4 on both sides were stimulated with 12 Hz., 2 to 5 V., a slight contraction of the levator ani muscle was elicited only with stimulation of the left spinal nerve of S3. During 3 days of test stimulation, the patient emptied the bladder completely. When stimulation was turned off near normal voiding ensued after 40 seconds (fig. 1). The voiding protocol indicated volumes of 200 to 800 ml. with residual volumes of less than 10%. When the test electrode was removed the patient was again unable to void. In December a permanent stimulator was implanted with the stimulating wire close to the left S3 spinal nerve (fig. 2). The stimulator (monopolar stimulation, 4.5 volts) was activated 3 days after implantation. With gradual cessation of back pain while in a sitting position (a consequence of surgery) the patient was increasingly able to relax the pelvic floor, resulting in complete bladder emptying. At followup in February 1999 urodynamic measurement during voiding revealed a detrusor contraction to 20 to 30 cm. water after the stimulator was turned off and the onset of voiding in about 1 minute. In April residual volumes of as much as 800 ml. and pain in the left buttock and thigh developed, and so stimulation was turned off. Initially electrode 1 was negative and the stimulator was positive. When electrode 3 was programmed to be negative the pain was gone and the stimulatAccepted for publication July 30, 1999. * Requests for reprints: Department of Urology, University of Munster, Albert Schweitzer Str. 33, 48129 Munster, Germany. FIG. 1. Micturition occurred after stimulation ceased