Prolonged Sacral Neuromodulation Testing Using Permanent Leads: a More Reliable Patient Selection Method?

Objective: To assess the effect of prolonged sacral neuromodulation testing using permanent leads comparing the usual evaluation period of 4 to 7 days to a prolonged evaluation period of a minimum of 14 days.

Patients And Methods: A consecutive series of 20 patients (16 females and 4 males) undergoing prolonged sacral neuromodulation testing using permanent leads between September 2000 and March 2004 were evaluated retrospectively. 10 suffered from urgency-frequency syndrome, 3 from urge incontinence and 7 from non-obstructive chronic urinary retention. Key bladder diary variables at baseline, after the usual and prolonged evaluation period and at the last follow-up were compared.

Results: The median age was 52 years (interquartile range (IQR) 38-59) and the median evaluation period 28 days (IQR 18-29). 16 of the 20 patients (80%) had successful prolonged sacral neuromodulation testing and underwent the implantation of the IPG that was placed in the anterior abdominal wall in 6 and in the upper buttock in 10 patients. The eligibility for IPG implantation was significantly (p=0.031) increased from 50% after the usual to 80% after the prolonged evaluation period. At a median follow-up of 22 months (IQR 12-34), sacral neuromodulation was successful in 14 (88%) of the 16 IPG implanted patients but failed in 2.

Conclusions: Prolonged sacral neuromodulation testing using permanent leads is more reliable for accurate patient selection than the usual evaluation period. Therefore, this method is strongly recommended and suggested to become the standard test procedure.