Is the screening method of sacral neuromodulation a prognostic factor for long-term success?

We evaluated whether there is a difference in long-term outcomes between patients screened with percutaneous nerve evaluation and a first stage tined lead procedure. We also evaluated the outcome in patients who only responded to screening with the tined lead procedure after failed initial percutaneous nerve evaluation.

We evaluated all patients screened for eligibility to receive sacral neuromodulation treatment since the introduction of the tined lead technique in our center in 2002. In May 2009 all implanted patients were asked to maintain a voiding diary to record the effect of sacral neuromodulation on urinary symptoms. Chi-square analysis was used to evaluate differences in the long-term outcomes of the separate screening methods.

A total of 92 patients were screened for sacral neuromodulation. Of the 76 patients screened with percutaneous nerve evaluation 35 (46%) met the criteria for permanent implantation. In 11 of the 16 patients (69%) who underwent direct screening with the tined lead procedure permanent stimulators were placed. Of the 41 patients in whom percutaneous nerve evaluation failed and who subsequently underwent screening with tined lead procedure 18 (44%) were implanted with a neurostimulator after a successful response. Statistical analysis showed no difference between screening type and long-term success (p = 0.94).

The first stage tined lead procedure is a more sensitive screening tool than percutaneous nerve evaluation but long-term success seems to be independent of the screening method. Patients in whom percutaneous nerve evaluation initially failed but who responded to prolonged screening the with tined lead procedure appeared to be as successful as those who directly responded to percutaneous nerve evaluation or the tined lead procedure.