[Bipolar stimulation may improve the efficacy of the percutaneous nerve evaluation test of sacral neuromodulation]. / Die bipolare Stimulation kann die Erfolgsrate des Peripheren Nervenevaluationstests der sakralen Neuromodulation verbessern.

Purpose This study evaluates the hypothesis that bipolar stimulation of the S3 and S4 sacral roots may enhance the efficacy of the percutaneous nerve evaluation (PNE) test. Material and Methods In this case-control-study, we enrolled 43 patients undergoing bipolar PNE and 57 controls undergoing unipolar PNE. For bipolar PNE, four test electrodes were placed at the bilateral S3 and S4 roots. The electrodes at the S3 and S4 roots of each side were connected to obtain bipolar stimulation. The test protocol over eight days included unilateral and bilateral stimulation of the S3 and S4 sacral roots. Eight days after implantation, the electrodes were removed and test results from bladder diaries were collected. Results The unipolar test procedure was successful in 47 % (27/57) of cases. The bipolar test procedure was successful in 58 % (25/43). In the bipolar group, 63 % (12/19) of patients with neurogenic tract dysfunction profited from treatment, vs. 57 % (13/23) in the unipolar group. Patients without a neurologic disease had a successful test in 58 % (14/24) of cases treated with bipolar PNE vs. 41 % (14/24) treated with unipolar PNE. Multivariate analysis did not reveal a statistically significant difference between groups. Conclusion Although not significant in this population, bipolar PNE may improve efficacy compared to the unipolar test procedure. Similar observations were made in subgroups of neurogenic and non-neurogenic bladder dysfunctions.

Sacral nerve stimulation for refractory overactive bladder in the elderly population.

PURPOSE: We determined the long-term outcome of sacral nerve stimulation for refractory overactive bladder in the elderly population. MATERIALS AND METHODS: We performed a prospective longitudinal study to better characterize the outcome of sacral nerve stimulation in female patients 70 years old or older with refractory overactive bladder. Demographic and perioperative data were recorded. Patients were followed postoperatively for evidence of successful stage conversion, device durability and efficacy, and postoperative complications. Patients were retrospectively compared to a cohort of female patients younger than 70 years with refractory overactive bladder. Statistical analysis was performed. RESULTS: Between July 2001 and February 2008, 19 elderly female patients with refractory overactive bladder underwent stage 1 lead placement. Of the patients 17 (90%) who reported greater than 50% improvement in symptoms based on a 1-week followup voiding log underwent implantable pulse generator placement. No intraoperative or immediate postoperative complications were noted. At a mean followup of 48.5 months 11 patients (65%) had a functional implantable pulse generator with greater than 50% objective improvement over baseline. Compared to matched patients younger than 70 years elderly patients had a similar conversion rate and adverse events but were significantly more likely to undergo device removal (p = 0.018). CONCLUSIONS: Based on our experience elderly patients have a high conversion rate, few adverse events, and a high level of device efficacy and durability with sacral nerve stimulation. Although more mature multicenter data are needed, it appears that sacral nerve stimulation in geriatric patients is safe and efficacious, and should be judiciously offered to those with refractory voiding symptoms.

Incidence and predictors of complications with sacral neuromodulation.

OBJECTIVES: To determine the incidence and predictors of complications with sacral nerve stimulation (SNS). METHODS: A prospective, longitudinal analysis of all patients treated with SNS was performed to define the incidence of complications and identify the predictors of these adverse events (AEs). All patients underwent staged SNS placement with the InterStim device for treatment of refractory voiding dysfunction. The patients were followed up for evidence of AEs and device efficacy. The patient and device variables were examined statistically for evidence of predictive value. RESULTS: From September 2001 to March 2008, 221 patients with a mean age of 48.8 years underwent SNS lead placement for the treatment of intractable urinary urgency/frequency (n = 121), urge incontinence (n = 63), or urinary retention (n = 37). Of this group, 202 patients (91.4%) experienced a >50% improvement in symptoms and underwent implantable pulse generator placement. At a mean follow-up of 36.9 months, 67 patients (30.3%) had experienced AEs (pain in 6, elective removal in 10, lack of efficacy in 11, trauma in 18, infection in 7, hematoma in 3, and lead migration in 12) requiring 44 lead revisions and 47 implantable pulse generator revisions. The significant predictors of AEs included a history of trauma (P < .001), a change in body mass index class (P < .001), enrollment in a pain clinic (P = .008), the duration of follow-up (P = .002), and a history of AEs (P < .001). CONCLUSIONS: The results of our study have shown that SNS is an effective treatment for patients with intractable voiding dysfunction. Complications are not uncommon but can be minimized with better patient selection.