Sacral Nerve Stimulation Works, but Beware of Adverse Events.

SCOTTSDALE, ARIZ. -- Implanted sacral nerve stimulators can work wonders in patients with bladder overactivity or urinary retention, but the treatment comes with its share of problems, Dr. Jeffrey L. Cornella said.

The procedure is approved for patients who have failed at least two trials of medications for overactive bladder as well as some form of conservative therapy. The prime candidate is a young patient with idiopathic bladder retention without obstruction who has to self-catheterize to void. "People who have not voided in years may void the same day" they get the implant, he said at a urogynecology meeting sponsored by the Mayo Clinic Scottsdale.

Nevertheless, the treatment can have adverse effects such as pain at the neurostimulator site or transient electrical shock. About 15% of patients require reoperation, said Dr. Cornella of the clinic.

Normally, candidates for the device undergo a 3- to 7-day test in which electrodes are inserted in their [S.sub.3] foramen, taped in place over the sacrum, and attached to an external stimulating device. If the test produces at least a 50% improvement in symptoms, the patient qualifies for a permanent implant.

Somewhat paradoxically, sacral nerve stimulation can treat both bladder retention and overactivity through sensory functions. How the device works is not well understood.

In a study published last year of 51 patients who received permanent implants, significant decreases in voiding frequency, urinary volumes, and urgency were sustained at 6 months of follow-up, said Dr. Cornella, who disclaimed any financial interest in the device.

In a separate prospective study of 581 patients with urge incontinence, urgency-frequency problems, or bladder retention, those who responded to the test stimulation were randomized to immediate permanent ...