Six years of experience with sacral nerve stimulation for fecal incontinence.

PURPOSE: Sacral nerve stimulation is one of many new surgical modalities for fecal incontinence. Short-term results from sacral nerve stimulation have been more encouraging than those from other modalities. The aim of this study was to report the outcome of percutaneous nerve evaluation tests and sacral nerve stimulation for the treatment of fecal incontinence from a single center covering a period of 6 years since the procedure was introduced. METHODS: All of the candidates for a percutaneous nerve evaluation test and sacral nerve stimulation seen at our anal physiology unit between March 2001 and March 2007 were included in the study. RESULTS: A total of 177 patients with fecal incontinence (160 females), median age 59.5 (range, 27-88) years, underwent a percutaneous nerve evaluation test. Of these patients, 142 (80%) had a positive test, including 21 of 25 (84%) patients who required a repeat percutaneous nerve evaluation test. Because of a functional failure, 16 patients underwent a revision of the permanent electrode, 7 of whom (44%) were satisfied with the functional result after the revision. Of 126 patients, 15 (12%) have undergone an explantation, with an infection rate of only 1.6%. Overall, after a median follow-up of 24 (range, 3-72) months, the median Wexner incontinence score decreased from 16 (range, 6-20) to 10 (range, 0-20) (P < .0001). In the 10 patients who underwent at least 6 years of treatment, the effect was sustained, as the median Wexner incontinence score decreased from 20 (range, 12-20) to 7 (range, 2-11) (P < .0001). CONCLUSION: Sacral nerve stimulation is a simple, safe, and minimally invasive technique with low morbidity and excellent results, which appear to be maintained for the first 6 years after the procedure. For patients who underwent the treatment, median Wexner incontinence score decreased significantly after a median follow-up of 24 (range, 3-72) months. Twelve percent were explanted. The infection rate was 1.6%.

Retention test in sacral nerve stimulation for fecal incontinence.

INTRODUCTION: Sacral nerve stimulation has become an established treatment for patients with fecal incontinence. However, the mechanism of its action remains obscure. We aim to assess whether sacral nerve stimulation improves patients' ability to retain rectal content. METHODS: Patients who had been treated successfully with sacral nerve stimulation underwent four retention tests during which the stimulator was turned either on or off. Both the patients and investigators were blinded to the status of the stimulator. The retention test results were assessed for interassessment agreement and for any differences between the on and off phases. Wexner scores, anorectal physiology tests, and patients' perceptions of stimulator settings were also recorded. RESULTS: Nineteen patients (16 women; mean age, 57.5 years) took part in the study. Retention tests showed moderate interassessment agreement (weighted Cohen's kappa index, 0.45). There were no sharp differences in retained volume between the stimulator's on and off phases (median 50 (range, 0-300) mL vs. 50 (range, 0-300) mL; P = 0.85). CONCLUSION: Sacral nerve stimulation does not alter patients' ability to retain rectal content. Further studies are needed to investigate the mechanism of sacral nerve stimulation.

A prospective, randomized study: switch off the sacral nerve stimulator during the night?

PURPOSE: Sacral nerve stimulation is an effective treatment for fecal incontinence. Some have recommended to "switch off" the pacemaker during the night to extend the lifetime of the expensive pacemaker. This study was designed to investigate whether a nightly "switch off" affects the clinical results of sacral nerve stimulation. METHODS: Twenty patients successfully treated with sacral nerve stimulation (19 females; median age, 59 (range, 36-72) years) were randomized to: Group A, pacemaker continuously "on" for three weeks followed by three weeks with the pacemaker "off" during the night, or Group B, opposite order. Daily bowel-habit diary, Wexner, and St. Mark's incontinence scores were obtained. RESULTS: One failed to return the daily bowel-habit diary, leaving 19 participating patients. Median Wexner incontinence score increased from 6 (range, 2-14) to 7 (range, 3-16) during the "off" period (P = 0.04), whereas St. Mark's incontinence score increased from 10 (range, 3-16) to 11 (range, 3-18; P = 0.03). Median number of days with soiling per three weeks increased from 0 (range, 0-12) to 1 (range, 0-15) during the "off" period (P = 0.008). Seven of 19 had more days with soiling during the "off" period. Defecation frequency per three weeks increased from 26 (range, 11-71) to 34 (range, 9-70) during the "off" period (P = 0.19). Only four continued with a nightly "switch off" after the study. CONCLUSIONS: It could be considered to recommend compliant patients to "switch off" the pacemaker during the night to extend the lifetime of the pacemaker. One-third experienced increased soiling, and they should turn the pacemaker on all day and night. Among the remaining, only a minor proportion will be motivated for turning the pacemaker off.

Impedance planimetric description of normal rectoanal motility in humans.

PURPOSE: Manometry and pressure-volume measurements are commonly used to study anorectal physiology. However, the methods are limited by several sources of error. Recently, a new impedance planimetric system has been introduced in a porcine model. It allows simultaneous determination of anorectal pressures and multiple rectal luminal cross-sectional areas. This study was designed to study normal human rectoanal motility by means of impedance planimetry with multiple rectal cross-sectional areas and rectal and anal pressure. METHODS: Twelve healthy volunteers (10 females), aged 24 to 53 years, were studied during one-hour fasting and one hour after a meal. Rectal cross-sectional areas were determined at five levels each 2 cm apart, as well as rectal and anal pressure. RESULTS: A number of rectoanal motility patterns were observed. A total of 25 episodes with very localized cyclic rectal contractions detected at only one of five channels were observed lasting two to four minutes with a median frequency of three per minute (range, 2-6). A total of 44 episodes of cyclic rectal contractions propagating over two or more channels were detected lasting 2 to 36 minutes. Most were associated with contractions of the anal canal. A significant increase in rectal contractile activity was observed after the meal (P < 0.05). Single rectal contractions were observed in 11 subjects, and the majority were located to one channel and lasted less than 40 seconds. In two subjects who felt a need to defecate during the experiment, the cross-sectional area at all channels showed strong cyclic contractile activity and the anal pressure increased by approximately 100 percent. CONCLUSIONS: The new rectal impedance planimetry system allows highly detailed description of rectoanal motility patterns. It has promise as a new method for description of rectoanal motility in further studies.

Rectal volume tolerability and anal pressures in patients with fecal incontinence treated with sacral nerve stimulation.

PURPOSE: Sacral nerve stimulation has proven to be a promising treatment for fecal incontinence when conventional treatment modalities have failed. There have been several hypotheses concerning the mode of action of sacral nerve stimulation, but the mechanism is still unclear. This study was designed to evaluate the results of rectal volume tolerability, rectal pressure-volume curves, and anal pressures before and six months after permanent sacral nerve stimulation and to investigate the mode of action of sacral nerve stimulation. METHODS: Twenty-nine patients with incontinence (male/female ratio = 6/23; median age, 58 (range, 29-79) years) underwent implantation of a permanent sacral electrode and neurostimulator after a positive percutaneous nerve evaluation test. Wexner incontinence score, rectal distention with thresholds for "first sensation," "desire to defecate," and "maximal tolerable volume," rectal pressure-volume curves, anal resting pressure, and maximum squeeze pressure were evaluated at baseline and at six months follow-up. RESULTS: Median Wexner incontinence score decreased from 16 (range, 6-20) to 4 (range, 0-12; P < 0. 0001). Median "first sensation" increased from 43 (range, 16-230) ml to 62 (range, 4-186) ml (P = 0.1), median "desire to defecate" from 70 (range, 30-443) ml to 98 (range, 30-327) ml (P = 0.011), and median "maximal tolerable volume" from 130 (range, 68-667) ml to 166 (range, 74-578) ml (P = 0.031). Rectal pressure-volume curves showed a significant increase in rectal capacity (P < 0.0001). The anal resting pressure increased significantly from 31 (range, 0-109) cm H(2)O to 38 (range, 0-111) cm H(2)O (P = 0.045). No significant increase in maximum squeeze pressure was observed. CONCLUSIONS: For patients with fecal incontinence successfully treated with sacral nerve stimulation, there was a significant increase in rectal volume tolerability and rectal capacity. A significant increase in anal resting pressure, but not in maximum squeeze pressure, was found. We suggest that sacral nerve stimulation causes neuromodulation at spinal level.

Urinary retention during sacral nerve stimulation for faecal incontinence: report of a case.

Sacral nerve stimulation (SNS) was proposed for the treatment of patients with urologic symptoms in 1967 but was not used until 1981. SNS has also proven to be a promising treatment in idiopathic faecal incontinence when conventional treatments have failed. The modality has been used for faecal incontinence since the mid-1990s. Eighty percent of the patients who were selected for percutaneous nerve evaluation (PNE) because of faecal incontinence report an improvement in the symptoms and qualify for a permanent implantation. Accordingly, SNS is now used for faecal incontinence and urologic symptoms. Reflex interactions between the bladder and the distal gastrointestinal tract are well known. The present case shows that SNS for faecal incontinence may significantly influence bladder function.