FORT LAUDERDALE, FLA. — Chronic sacral nerve stimulation with the implantable InterStim system bridges the gap between conservative treatment and highly invasive procedures such as urinary diversion, Dr. Gamal M. Ghoniem said at a symposium on pelvic floor disorders sponsored by the Cleveland Clinic Florida.
InterStim uses a small device to deliver mild electrical pulses to the sacral nerves that influence the behavior of the bladder, sphincter, and pelvic floor muscles.
The therapy should be considered before ablative or reconstructive surgery when medical therapy has failed, said Dr. Ghoniem, head of the section of voiding dysfunction, female urology, and reconstruction at the Cleveland Clinic Florida in Weston.
In a multicenter study conducted in Europe and North America, the mean number of urinary incontinence (UI) episodes per day decreased from 10 to 2.6 in 250 patients who were implanted with the InterStim device. Patients had chronic symptoms of urge incontinence, urgency frequency, and urinary retention.
After successful completion of a nerve stimulation test, the study population was divided into a delayed group and an implant group. The delayed group members served as controls for 3 and 6 months, and then were implanted.
At 6 months after implantation with InterStim, 47% of the urge incontinence patients were dry, and an additional 28% were greatly improved.
These results were maintained at 12 and 18 months. Urgency/frequency patients had a significant 50% reduction in the number of voids per day, and 61% of the urinary retention patients were able to resume urination without catheterization.
Another 16% had a significant reduction in the number of catheterizations per day, Dr. Ghoniem reported.
The controls did not show any significant improvement in their condition during the observation period, he added.
No permanent injuries were reported. Adverse side effects included pain (15% of patients), infection (6.1%), transient electric shock (5.5%), adverse change in bowel function (3%), and suspected lead migration (8.4%). Nevertheless, the patient satisfaction rate was 84%, Dr. Ghoniem said.
Since this study, there have been several improvements in the technique of implantation and in the equipment used.
The previous technique necessitated an incision in the abdomen to place the control unit, whereas now it is placed over the gluteal region. This shortens the duration of the procedure by 30–54 minutes.
The leads are now placed percutaneously, whereas before, they were placed via incisions over the sacrum. As a result, the incidence of adverse events is considerably lower than reported in the earlier review, Dr. Ghoniem said.
Suitable patients benefit greatly from this therapy, said Dr. Ghoniem. “This disorder can make people very upset and anxious. They have had urinary incontinence for years. They've tried different medications, different doctors, and nothing works—they still go to the bathroom all day and all night and they are miserable. But once this changes for them, they are ecstatic.”