The effect of sacral nerve modulation on cerebral evoked potential latency in fecal incontinence and constipation.

OBJECTIVE: Influence of sacral nerve modulation (SNM) on cerebral somatosensory evoked potentials (SEP) was determined in patients with incontinence and constipation. BACKGROUND: Selection of patients with incontinence and constipation for SNM could be improved. METHODS: The latency (ms) of SEP induced by pudendal nerve stimulation was compared before (T0) and at 1 month during peripheral nerve evaluation (PNE) of SNM at frequencies of 21 Hz (T1) and 40 Hz (T2). The results were correlated with clinical outcome at 6 months. RESULTS: In 16 of 23 incontinent patients with clinical "success" from SNM (Wexner incontinence score ≤7), there was a significant difference between P40 latency at T0 and T2 (38.81 vs. 37.49 ms, P = 0.049). In the 7 with "failure," there was no change between T0 and T2. In 12 of 19 constipated patients with "success" (Wexner constipation score ≤15), there was no difference between T0 and T2 P40 latency (39.28 vs. 38.25 ms, P = 0.374). In the 7 with "failure," there was a significant fall in P40 latency (41.20 vs. 39.30 ms, P = 0.047) but not to the normal range. The T0 P40 latency in incontinent patients having "success" was significantly higher than in the normal range (P = 0.044). In constipated patients it was significantly higher than in the normal range in both those with "success" (P = 0.001) and "failure" (P = 0.022). CONCLUSIONS: Measurement of P40 latency of SEP at baseline and at 1 month of SNM at a frequency of 40 Hz may help to predict the outcome of SNM and thus influence the decision for permanent implantation for patients with incontinence and constipation.

Interventional neurophysiology and an implantable system for neurostimulation of the sacral area.

Surgical or interventional neurophysiology is a term commonly used to refer to a large number of neurosurgical procedures involving the brain, cranial nerves, spinal cord and peripheral nervous system which, to be efficient and safe, demand specific neurophysiological know-how. As a result of the development of these procedures and their increasing use in the operating room, the role of clinical neurophysiology, traditionally diagnostic, has been extended. With the advent of 'neurostimulation' and 'neuromodulation', some neurophysiological techniques have, in themselves, progressively become more therapeutic, the therapeutic alteration of nervous system activity being achieved not only by surgical ablation or medication but also through electrophysiological means via implanted or non-implanted devices, whose development was made possible by extensive studies in the field of neurophysiology. The first application of electrical stimulation in urology opened up the way for progress in the therapeutic direction. Moreover, with regard to the mechanism of action underlying neuromodulation, the application of neurophysiology and neuroimaging procedures has contributed to understanding of the neural control mechanism of visceral (e.g. lower urinary tract) function. In our experience, the advent of sacral neuromodulation for lower urinary tract dysfunction and the use of neurophysiology has made it possible to shed light on the pathophysiological mechanisms of neuro-urological disorders, allowing us to assess and validate new therapeutic approaches and finally to develop a new method and device for chronic pudendal nerve stimulation.

Daily intravesical instillation of 1 mg nociceptin/orphanin FQ for the control of neurogenic detrusor overactivity: a multicenter, placebo controlled, randomized exploratory study.

PURPOSE: We studied the feasibility, safety and efficacy of daily intravesical instillation of 1 mg of the endogenous peptide nociceptin/orphanin FQ in a selected group of patients who perform clean intermittent self-catheterization for neurogenic detrusor overactivity incontinence. MATERIALS AND METHODS: A total of 18 patients with neurogenic detrusor overactivity incontinence and on clean intermittent self-catheterization were prospectively randomized to receive 1 mg nociceptin/orphanin FQ in 10 cc saline (9) or placebo (saline) solution (9) at the first morning catheterization for 10 days. All patients completed a voiding diary using a frequency/volume chart according to International Continence Society guidelines, and reported daily incontinence frequency. Mean changes in incontinence episode frequency and voiding diary mean bladder capacity from baseline throughout treatment were the primary outcome variables. Urodynamic parameters (cystomanometric bladder capacity, maximum bladder pressure) were also recorded at baseline and during the study. RESULTS: The 2 groups were well balanced and all patients completed the study. The urodynamic parameters recorded during the study showed an increase in cystomanometric bladder capacity and a decrease in maximum bladder pressure compared to baseline only in patients assigned to the nociceptin/orphanin FQ group. Mean daily urine leakage episodes during nociceptin/orphanin FQ treatment were 0.94 vs a pretreatment baseline of 2.18 (p < 0.05), while no significant changes were reported in the placebo group (2.06 vs 2.43 baseline). The total mean voiding diary bladder capacity increased from 171 +/- 70 to 294 +/- 107 ml in patients receiving nociceptin/orphanin FQ, while voiding diary mean bladder capacity remained unchanged in patients receiving placebo (from 182 +/- 55 to 178 +/- 23 ml). No significant problems related to feasibility of the procedure as well as significant side effects were reported by patients. CONCLUSIONS: This study showed that intravesical nociceptin/orphanin FQ but not placebo inhibited the micturition reflex in patients with neurogenic detrusor overactivity incontinence, and demonstrated the clinical efficacy of nociceptin/orphanin FQ during 10 days of treatment. These findings support the use of nociceptin/orphanin FQ peptide receptor agonists as an innovative therapeutic approach for controlling detrusor overactivity incontinence.

A new minimally invasive procedure for pudendal nerve stimulation to treat neurogenic bladder: description of the method and preliminary data.

AIMS: Pudendal nerve stimulation has beneficial effects on numerous pelvic floor function impairments such as urinary and/or fecal incontinence, retention, and constipation. In preceding literature the implant technique required a fairly complex and invasive surgery, although recent advances with percutaneous placement of the lead through an introducer have made the procedure much less invasive. We performed staged procedure similar to that of sacral neuromodulation (SNM) to place tined lead near the pudendal nerve, using neurophysiological guidance that allowed accurate pudendal nerve stimulation through either perineal or posterior approach. We have named this approach chronic pudendal nerve stimulation (CPNS). METHODS: Fifteen neurogenic patients (eight male, seven female) with symptoms of urge incontinence due to neurogenic overactive bladder underwent CPNS. All patients had complete neurophysiological and urodynamic evaluation at baseline and follow-up and were asked to complete voiding and bowel diary for 7 days. RESULTS: During screening, average number of incontinent episodes per day decreased from 7+/-3.3 to 2.6+/-3.3 (P<0.02, paired t-test). Eight patients became continent, two improved by more than 88% (from 9 to 1 daily incontinence episode) and two patients reduced the number of incontinence episodes by 50%. The implantable pulse generator (IPG) was subsequently implanted in those 12 patients. Three patients without improvement did not continue to second stage. In implanted patients with 6 months follow-up, urodynamic evaluation showed an objective improvement in the maximum cystometric capacity which increased from 153.3+/-49.9 to 331.4+/-110.7 ml (P<0.01, paired t-test). The maximum pressure decreased from 66+/-24.3 to 36.8+/-35.9 cmH2O (P=0.059, paired t-test). Eight patients reported significant improvement in bowel function. CONCLUSION: Chronic pundedal nerve stimulation is feasible. Neurophysiological guidance is mandatory to place the lead near the pudendal nerve either using perineal or posterior approach. Further studies must be carried out to identify the best stimulation parameters and to verify the long term results.

New sacral neuromodulation lead for percutaneous implantation using local anesthesia: description and first experience.

PURPOSE: In functional urology today chronic stimulation of the sacral nerves has become one of the most accepted methods of stimulation treatment. Many studies have described the advantage of test stimulation prior to implanting the definitive system to enable effective patient selection. We studied a method aimed at improving lead anchoring by developing a self-blocking electrode with a simple placement procedure, in the process creating a 2-stage approach to full percutaneous implantation that allows a long screening period during the first temporary stimulation stage. MATERIALS AND METHODS: A new tined lead was specifically designed to allow minimally invasive percutaneous lead placement requiring no incision and no additional fascial anchoring. From September 2001 to November 2002, 15 consecutive patients (3 males and 12 females) 27 to 70 years old (mean age 49) underwent this procedure and were prospectively evaluated. No PNE test was performed. RESULTS: Following the first stage screening phase 12 patients were implanted with the implantable pulse generator (IPG), while 3 who did not respond positively to test stimulation (neurogenic voiding dysfunction, urge incontinence and neurogenic urge incontinence in 1 each) did not undergo IPG implantation and had the tined lead removed under local anesthesia. We did not observe any lead displacement during the screening period (average 38.8 days) or during followup of IPG implanted cases (average 11 months, range 5 to 19). CONCLUSIONS: Our results show that the new tined anchoring system is a reliable way to allow truly minimally invasive placement of the chronic lead.