Safety of prolonged sacral neuromodulation tined lead testing

Prolonged sacral neuromodulation (SNM) testing is more reliable for accurate patient selection than the usual test period of 4-7 days. However, prolonged testing was suspected to result in a higher complication rate due to infection via the percutaneous passage of the extension wire. Therefore, we prospectively assessed the complications associated with prolonged tined lead testing.

A consecutive series of 44 patients who underwent prolonged tined lead testing for at least 14 days between May 2002 and April 2007 were evaluated. Complications during prolonged tined lead testing, during and after tined lead explantation and during follow-up after implantation of the implantable pulse generator (IPG) were registered prospectively.

Four patients suffered from urgency-frequency syndrome, 13 from urge incontinence, 18 from non-obstructive chronic urinary retention and nine from chronic pelvic pain syndrome. The median test phase was 30 days (interquartile range [IQR] 21-36). Thirty-two of the 44 patients (73%) had successful prolonged tined lead testing and 31 of these (97%) underwent the implantation of the IPG. The median follow-up of the IPG implanted patients was 31 months (IQR 20-41). The complication rate was 5% (2/44) during prolonged tined lead testing and 16% (5/31) during follow-up of the IPG implanted patients, respectively. None of the complications could be attributed to prolonged testing. No infections were observed during the study period.

This prospective, observational non-randomised study suggests prolonged SNM tined lead testing is a safe procedure. Based on the low complication rate and the increased reliability for accurate patient selection, this method is proposed as a possible standard test procedure, subject to confirmation by further randomised, controlled clinical studies.