Sacral nerve stimulation for treatment of fecal incontinence: a novel approach for intractable fecal incontinence

PURPOSE: Many patients with fecal incontinence demonstrate a functional deficit of the internal anal sphincter or the external sphincter muscles without any apparent structural defects. Few patients are amenable to repair or substitution of the sphincter. However, sacral nerve stimulation appears to offer a valid treatment option for fecal incontinence. The objectives of this study were: to evaluate the efficacy of temporary stimulation of the sacral nerve roots (percutaneous nerve evaluation) in patients with functional fecal incontinence; to determine the mechanisms of possible improvement; and to evaluate if temporary stimulation could be reproduced and maintained by implanting a permanent neurostimulation system. METHODS: Twenty-three patients with fecal incontinence, 18 females and 5 males, median age of 54.9 years (range 28-71), underwent a percutaneous nerve evaluation test. Eleven patients (47.8 percent) also had urinary disorders: urge incontinence (4), stress incontinence (3), and retention (4). Associated disorders included perineal and rectal pain (1), spastic paraparesis (1), and syringomyelia (1). All patients underwent a preliminary evaluation using stationary anal manovolumetry, pudendal nerve terminal motor latency measurements, and anal ultrasound. A percutaneous electrode for the stimulation of the sacral nerve roots was positioned at the level of the third sacral foramen (S3) in 20 patients and S2 in 2 patients (1 patient missing). Stimulation parameters used were: pulse width 210 microsec, frequency 25 Hz, and average amplitude of 2.8 V (range 1-6). The electrode was left in place for a minimum of 7 days. Five patients were successively implanted with a permanent sacral electrode with a stimulation frequency of 16 to 18 Hz and amplitude of 1.1- 4.9 V. RESULTS: Seventeen of the 19 patients (89.4 percent) who completed the minimum percutaneous nerve evaluation period of 7 days (median 10.7 (range 7-30)), had a reduction of liquid or solid stool incontinence by more than 50 percent, and fourteen (73.6 percent) were completely continent for stool. The most important changes revealed by manovolumetry were an increase in resting pressure (P < 0.001) and voluntary contraction (P = 0.041), reduction of initial pressure for first sensation (P = 0.049) and urge to defecate (P = 0.002), and a reduction of the rectal volume for urge sensation (P = 0.006). The percutaneous nerve evaluation results were reproduced at a median follow-up of 19.2 months (range 5 to 37) in the 5 patients who received a permanent implant. CONCLUSIONS: Temporary stimulation of the sacral roots (percutaneous nerve evaluation) can be of help in those patients with fecal incontinence, and the results are reproduced with permanent implantation. The positive effect on continence seems to be derived from not only the direct efferent stimulation on the pelvic floor and the striated sphincter muscle, but also from modulating afferent stimulation of the autonomous neural system, inhibition of the rectal detrusor, activation of the internal anal sphincter, and modulation of sacral reflexes that regulate rectal sensitivity and motility.     

Bilateral sacral spinal nerve stimulation for fecal incontinence after low anterior rectum resection

BACKGROUND AND AIMS: The somatomotor innervation pattern has been shown to differ in patients undergoing percutaneous nerve evaluation for sacral nerve stimulation. In some patients bilateral stimulation might improve clinical outcome; however, only single-channel pulse generators have until now been available. We report a patient with fecal incontinence after surgery for rectal carcinoma in whom a dual-channel, individually programmable, pulse generator permitted implantation of neurostimulation electrodes bilaterally. PATIENTS AND METHODS: Intractable fecal incontinence developed in a 48-year-old man who underwent low anterior rectum resection, owing mainly to reduced internal anal sphincter function. The morphology of the anal sphincter was without defect. Based on the findings of unilateral and bilateral temporary sacral nerve stimulation the patient underwent placement of foramen electrodes on S4 bilaterally. Both electrodes were connected to a dual-channel impulse generator for permanent low-frequency stimulation. RESULTS: The percentage of incontinent bowel movements decreased during unilateral test stimulation from 37% to 11%, during bilateral test stimulation to 4%, and with chronic bilateral stimulation to 0%. The Wexner continence score improved from 17 preoperatively to 2, and quality of life (ASCRS score) was notably enhanced. Anorectal manometry revealed improved striated anal sphincter function; the internal anal sphincter remained unaffected. CONCLUSION: Sacral nerve stimulation can effectively treat incontinence after rectal resection, and bilateral stimulation can improve the therapeutic effect.     

Sacral Nerve Stimulation in Fecal Incontinence

PURPOSE: The effect of sacral nerve stimulation was studied in 45 patients with fecal incontinence.METHODS: All patients were initially tested in general anesthesia. Sacral nerves 2, 3, and 4 were tested on both sides. If a perineal/perianal muscular response to sacral nerve stimulation could be obtained, electrodes were implanted for a three-week test-stimulation period. If sacral nerve stimulation resulted in at least a 50 percent reduction in incontinence episodes during the test period, a system for permanent sacral nerve stimulation was implanted.RESULTS: When tested in general anesthesia, 43 of 45 patients had a muscular response to sacral nerve stimulation and had electrodes implanted for the three-week test period. Percutaneous electrodes were used in 34 patients, and 23 of these had at least a 50 percent reduction in incontinence episodes, whereas the electrodes dislocated in 7 patients and 4 had a poor response. Permanent electrodes with percutaneous extension electrodes were used primarily in 9 patients and after dislocation of percutaneous electrodes in an additional 6 patients; 14 of these had a good result. In the last patient, no clinical response to stimulation with the permanent electrode could be obtained. A permanent stimulation system was implanted in 37 patients. After a median of six (range, 0–36) months follow-up, five patients had the system explanted: three because the clinical response faded out, and two because of infection. Incontinence score (Wexner, 0–20) for the 37 patients with a permanent system for sacral nerve stimulation was reduced from median 16 (range, 9–20) before sacral nerve stimulation to median 6 (range, 0–20) at latest follow-up (P < 0.0001). There was no differences in effect of sacral nerve stimulation in patients with idiopathic incontinence (n = 19) compared with spinal etiology (n = 8) or obstetric cause of incontinence (n = 5). Sacral nerve stimulation did not influence anal pressures or rectal volume tolerability.CONCLUSIONS: Sacral nerve stimulation in fecal incontinence shows promising results. Patients with idiopathic, spinal etiology, or persisting incontinence after sphincter repair may benefit from this minimally invasive treatment.Presented at the meeting of The American Society of Colon and Rectal Surgeons, New Orleans, Louisiana, June 21 to 26, 2003.Reprints are not available.     

Rectal Hypersensitivity Worsens Stool Frequency, Urgency, and Lifestyle in Patients With Urge Fecal Incontinence

PURPOSE Rectal sensory mechanisms are important in the maintenance of fecal continence. Approximately 50 percent of patients with urge incontinence have lowered rectal sensory threshold volumes (rectal hypersensitivity) on balloon distention. Rectal hypersensitivity may underlie the heightened perception of rectal filling; however, its impact on fecal urgency and incontinence is unknown. This study was designed to investigate the impact of rectal hypersensitivity in patients with urge fecal incontinence.METHODS Prospective and retrospective audit review of all patients (n = 258) with an intact native rectum referred to a tertiary colorectal surgical center for physiologic investigation of urge fecal incontinence during a 7.5-year period. Patients with urge fecal incontinence who had undergone pelvic radiotherapy (n = 9) or rectal prolapse (n = 6) were excluded.RESULTS A total of 108 of 243 patients (44 percent) were found to have rectal hypersensitivity. The incidence of anal sphincter dysfunction was equal (90 percent) among those with or without rectal hypersensitivity. Patients with urge fecal incontinence and rectal hypersensitivity had increased stool frequency (P < 0.0001), reported greater use of pads (P = 0.003), and lifestyle restrictions (P = 0.0007) compared with those with normal rectal sensation, but had similar frequencies of incontinent episodes.CONCLUSIONS Urge fecal incontinence relates primarily to external anal sphincter dysfunction, but in patients with urge fecal incontinence, rectal hypersensitivity exacerbates fecal urgency, and this should be considered in the management and surgical decision in patients who present with fecal incontinence.Christopher L. H. Chan, F.R.C.S., is supported by a MRC Clinical Training Fellowship.     

Sacral nerve neuromodulation improves physical,psychological and social quality of life in patients with fecal incontinence

There are several therapeutic options for fecal incontinence but often they do not achieve good results in the long run. This study dealt with sacral nerve modulation, a new therapeutic option. Twenty-one patients underwent pudendal nerve evaluation (PNE) at our institution. Nine patients were affected by both fecal and urinary incontinence, 3 had fecal incontinence and anal pain, 5 had fecal incontinence and pelvic floor dyssynergia, and 4 had isolated fecal incontinence. They underwent morphological, functional and psychological tests prior to PNE, showing no sphincter rupture, almost normal anal pressures, impaired rectal sensation and deficient psychological pattern. All patients underwent at least two nerve evaluations. Four of 21 patients (19%) were selected to receive a permanent sacral electrode, as PNE seemed to have improved their symptoms by >75%. A median follow-up of 15 months (range, 6–24 months) showed that this method decreases weekly episodes of incontinence and increases maximal squeeze pressure. We demonstrated an increase in basal pressure in 3 of 4 patients (all with isolated fecal incontinence). Rectal sensation threshold decreased in three patients; urge threshold decreased in two patients and increased in two patients, but in each patient we got a stabilization. We evaluated the quality of life by applying the Short Form Health Survey test (SF-36). All 4 patients showed a significant increase in the scores of physical, emotional and social role functioning after the permanent implant. In conclusion, sacral nerve modulation may improve physical, physiological and social quality of life in selected groups of incontinent patients without gross sphincter lesions and with impaired rectal sensation. Received: 6 June 2002 / Accepted: 10 November 2002     

Sacral Nerve Stimulation Can Be Successful in Patients With Ultrasound Evidence of External Anal Sphincter Disruption

PURPOSE This study was designed to determine whether patients with fecal incontinence and endoanal ultrasound evidence of anal sphincter disruption may be successfully treated by sacral nerve stimulation.METHODS Five consecutive females with incontinence to solids and endoanal ultrasound evidence of anal sphincter disruption were treated by a two-week trial of sacral nerve stimulation. If successful, patients then proceeded to permanent sacral nerve stimulation implantation.RESULTS Five patients, aged 34 to 56 years, were treated by temporary sacral nerve stimulation. Four had symptoms starting after childbirth. Two had previously had an anterior sphincter repair. After a two-week trial, three females reported full continence and an improvement in all aspects of their Rockwood fecal incontinence quality of life scores. These three females underwent permanent sacral nerve stimulation implantation. The remaining two patients reported no improvement and underwent dynamic graciloplasty or end colostomy respectively.CONCLUSIONS Sacral nerve stimulation may successfully restore bowel continence in some patients with endoanal ultrasound evidence of a defect in their external anal sphincter.     

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 H₂O to 38 (range, 0–111) cm H₂O (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. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, April 30 to May 5, 2005.     

Reliability of Electrophysiologic Anal Tests in Predicting the Outcome of Sacral Nerve Modulation for Fecal Incontinence

INTRODUCTION: Sacral nerve modulation has been demonstrated to be a new efficacious treatment for fecal incontinence. The effectiveness of the procedure is preliminarily tested by means of a peripheral nerve evaluation. Integrity of the sacral neural pathway is generally believed to be a necessary condition for a good response, but no data are available to confirm whether electrophysiologic anal tests are predictive of the clinical outcome of the peripheral nerve evaluation.METHODS: Eighty-two incontinent patients underwent the peripheral nerve evaluation after full evaluation of the anorectal physiology. Univariate analysis was performed, and the positive predictive value, sensitivity, and specificity were calculated for each of the tests.RESULTS: Forty-six patients had successful results to the peripheral nerve evaluation and were subjected to permanent implant of a sacral electrostimulator. Anal sphincter electromyography had been performed in 60 patients, whereas pudendal nerve terminal motor latency had been assessed in 68 and evoked sacral potentials in 29 patients. Anal electromyography was statistically related to the outcome of the peripheral nerve evaluation (P = 0.0004) with a positive predictive value of 81 percent, a sensitivity of 44 percent, and a specificity of 81 percent. Pudendal nerve terminal motor latency on the right side did not correlate with the outcome, but left pudendal nerve terminal motor latency was weakly correlated (P = 0.02), although both tests had a low positive predicting value and sensitivity vs. good specificity. Evoked sacral potentials did not correlate with the outcome and had a low positive predictive value, sensitivity, and specificity.CONCLUSIONS: Simple anal sphincter electromyography can predict the outcome of the peripheral nerve evaluation with good positive predictive value and specificity in patients with fecal incontinence. Other, more expensive, electrophysiologic anal tests do not add further prognostic information.Read at the meeting of The American Society of Colorectal Surgeons, New Orleans, Louisiana, June 21 to 26, 2003.     

Sacral Nerve Stimulation for Fecal Incontinence: External Anal Sphincter Defect <Emphasis Type="Italic">vs</Emphasis>. Intact Anal Sphincter

Purpose  This prospective study was designed to assess the effectiveness of sacral nerve stimulation for fecal incontinence in patients with external anal sphincter defect and to evaluate its efficacy regarding presence and size of sphincter defect. Methods  Fifty-three consecutive patients who underwent sacral nerve stimulation for fecal incontinence were divided into two groups: external anal sphincter defect group (n = 21) vs. intact sphincter group (n = 32). Follow-up was performed at 3, 6, and 12 months with anorectal physiology, Wexner’s score, bowel diary, and quality of life questionnaires. Results  The external anal sphincter defect group (defect <90°:defect 90°–120° = 11:10) and intact sphincter group were comparable with regard to age (mean, 63 vs. 63.6) and sex. Incidence of internal anal sphincter defect and pudendal neuropathy was similar. All 53 patients benefited from sacral nerve stimulation. Weekly incontinent episodes decreased from 13.8 to 5 (P < 0.0001) for patients with external anal sphincter defects and from 6.7 to 2 (P = 0.001) for patients with intact sphincter at 12-month follow-up. Quality of life scores improved in both groups (P < 0.0125). There was no significant difference in improvement in functional outcomes after sacral nerve stimulation between patients with or without external anal sphincter defects. Clinical benefit of sacral nerve stimulation was similar among patients with external anal sphincter defects, irrespective of its size. Presence of pudendal neuropathy did not affect outcome of neurostimulation. Conclusions  Sacral nerve stimulation for fecal incontinence is as effective in patients with external anal sphincter defects as those with intact sphincter and the result is similar for defect size up to 120° of circumference. ^†Deceased.     

Sacral Nerve Stimulation in Fecal Incontinence: Are There Factors Associated with Success?

Purpose Sacral nerve stimulation has been used successfully in treating fecal incontinence. This study was designed to evaluate the proportion of patients with unsuccessful implantation despite positive test stimulation and to examine and compare factors associated with the success of the transitory and permanent sacral nerve stimulation. Methods A total of 61 patients (55 females; median age, 56 (range, 33–77) years) with refractory fecal incontinence underwent temporary stimulation. A 50 percent or greater improvement in the number of episodes of fecal incontinence or urgency was required to proceed to permanent implantation and was the criteria of success of permanent sacral nerve stimulation at the last follow-up visit in implanted patients. The factors compared between the success and the failure groups during temporary and permanent stimulation were patients’ age and gender, diagnosis and characteristics of fecal incontinence, previous surgery, quality of life scores, anorectal manometry, endoanal ultrasound, and electrophysiologic tests performed before stimulation. Results Temporary stimulation was successful in 35 patients (57.4 percent). A permanent neurostimulation device was implanted in 33 patients. Age was the only factor related to success of the temporary stimulation (P=0.03). After permanent implantation, 31 percent of patients did not attain screening phase results for the number of episodes of fecal incontinence or urgency. A neurologic disorder was more frequently the origin of fecal incontinence in the success group compared with others (P=0.03). The left bulbocavernosus reflex was more frequently delayed in the success group than in the others (P=0.03), and a prolonged or absent bulbocavernosus reflex was more frequent in the success group than in the failure group (P=0.03). Conclusions Patients with fecal incontinence from neurologic origins could be good candidates for sacral nerve stimulation. Presented at Digestive Disease Week, Los Angeles, California, May 20 to 25, 2006.     

Sacral Neuromodulation in Treatment of Fecal Incontinence Following Anterior Resection and Chemoradiation for Rectal Cancer

PURPOSE Fecal incontinence may occur in patients who have undergone anterior resection for rectal cancer without presenting sphincter lesions. Chemoradiation may contribute to disrupting continence mechanisms. Treatment is controversial. Assessment of fecal incontinence in patients who agreed to integrate treatment for rectal cancer and treatment with sacral neuromodulation are reported.METHODS Fecal incontinence following preoperative chemoradiation and anterior resection for rectal cancer was evaluated in four patients. A good response was observed during the percutaneous sacral nerve evaluation test, and so permanent implant of sacral neuromodulation system was performed. Reevaluation was performed at least two months after implant.RESULTS After device implantation, the mean fecal incontinence scores decreased, and the mean number of incontinence episodes dropped from 12.0 to 2.5 per week (P < 0.05). Permanent implant resulted in a significant improvement in fecal continence in three patients, and incontinence was slightly reduced in the fourth. Manometric parameters agreed with clinical results: maximum and mean resting tone and the squeeze pressure were normal in three patients and reduced in one. In these same three patients, neorectal sensation parameters increased when the preoperative value was normal or below normal and decreased when the preoperative value was higher than normal, whereas in one patient in whom extremely low values were recorded all of the parameters decreased significantly.CONCLUSIONS Fecal incontinence following anterior resection and neoadjuvant therapy should be carefully evaluated. If a suspected neurogenic pathogenesis is confirmed, sacral neuromodulation may be proposed. If the test results are positive, permanent implant is advisable. Failure of this approach does not exclude the use of other, more aggressive treatment.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004.     

Evaluation of the sacroanal motor pathway by magnetic and electric stimulation in patients with fecal incontinence

PURPOSE: The aim of this controlled study was to examine whether it was feasible to use magnetic stimulation as a new diagnostic tool to evaluate the motor function of the sacral roots and the pudendal nerves in patients with fecal incontinence. PATIENTS AND METHODS: Nineteen consecutive patients (17 females) with a median age of 67 (range, 36–78) years referred for fecal incontinence and 14 healthy volunteers (six females) with a median age of 42 (range, 23–69) years were examined. Latency times of the motor response of the external anal sphincter were measured after electric transrectal stimulation of the pudendal nerve and magnetic stimulation of the sacral roots. RESULTS: The success rates of pudendal nerve terminal motor latency and sacral root terminal motor latency measurements were 100 and 85 percent, respectively, in the control group and 94 and 81 percent, respectively, in the fecal incontinence group. Median left pudendal nerve terminal motor latency was 1.88 (range, 1.4–2.9) milliseconds in the control group and 2.3 (range, 1.8–4) milliseconds in the fecal incontinence group (P<0.006). Median right pudendal nerve terminal motor latency was 1.7 (range, 1.3–3.4) milliseconds in the control group and 2.5 (range, 1.7–6) milliseconds in the fecal incontinence group (P<0.003). Median left sacral root terminal motor latency was 3.3 (range, 2.1–6) milliseconds in the control group and 3.7 (range, 2.8–4.8) milliseconds in the fecal incontinence group (P<3 0.03). Median right sacral root terminal motor latency was 3 (range, 2.6–5.8) milliseconds in the control group and 3.9 (range, 2.5–7.2) milliseconds in the fecal incontinence group (P=0.15). CONCLUSIONS: Combined pudendal nerve terminal motor latency and sacral root terminal motor latency measurements may allow us to study both proximal and distal pudendal nerve motor function in patients with fecal incontinence. Values of sacral root terminal motor latency have to be interpreted cautiously because of the uncertainty about the exact site of magnetic stimulation and the limited magnetic field strength.     

Sacral Nerve Stimulation for Fecal Incontinence Following Surgery for Rectal Prolapse Repair: A Multicenter Study

PURPOSE: A proportion of patients have fecal incontinence secondary to a full-thickness rectal prolapse that fails to resolve following prolapse repair. This multicenter, prospective study assessed the use of sacral nerve stimulation for this indication. METHODS: Patients had to have more than or equal to four days with fecal incontinence per 21-day period more than one year after surgery. They had to have failed conservative treatment and have an intact external anal sphincter. RESULTS: Four female patients aged 42, 54, 68, and 65 years met the inclusion criteria. Three of the four patients had had more than one operation for recurrent full-thickness rectal prolapse before sacral nerve stimulation, one of whom had undergone a further operation for recurrence following stimulation. One patient had undergone one operation for prolapse repair. The preoperative duration of symptoms was ten, eight, three, and nine years, respectively. Although patients had an intact external anal sphincter, one patient had a fragmented internal anal sphincter. The frequency of fecal incontinent episodes changed from 11, 24.7, 5, and 8 per week at baseline to 0, 1.5, 5.5, and 1 per week at latest follow-up. Ability to defer defecation was also improved in two of three patients who had this documented. Fecal incontinence-specific quality of life assessment showed an improvement in all four domains. CONCLUSION: Sacral nerve stimulation should be considered for patients with ongoing fecal incontinence following full-thickness rectal prolapse repair if they prove resistant to conservative treatment.     

Results of neurophysiologic evaluation in fecal incontinence

PURPOSE: Several methods of neurophysiologic assessment exist in the investigation of patients with fecal incontinence. However, the clinical significance of the information gained is uncertain. The aim of this prospective study was to evaluate the results of pudendal nerve terminal motor latency and fiber density in relation to clinical variables and manometric measurements. METHODS: Seventy-two patients with fecal incontinence (63 women; mean age, 62; range, 24–81 years) responded to a bowel questionnaire and underwent anorectal manovolumetry, anal ultrasonography, defecography, and electromyography, including pudendal nerve terminal motor latency and fiber density. RESULTS: Pudendal neuropathy (pudendal nerve terminal motor latency >2.5 ms) was found in 46 percent and increased fiber density (>1.7) in 82 percent. Pudendal neuropathy and increased fiber density were most common in patients with rectal prolapse or intra-anal intussusception. No difference was seen concerning anal resting and incremental pressures, rectal compliance, rectal sensibility or severity of incontinence in patients with unilateral, bilateral, or marked (>4 ms) pudendal neuropathyvs. patients with normal pudendal nerve terminal motor latency. In contrast, patients with increased fiber density had lower incremental pressures (P<0.05) and stated decreased rectal sensibility (P<0.05) compared with those with normal fiber density. These differences were most pronounced in patients with neurogenic or idiopathic incontinence. CONCLUSIONS: Pudendal neuropathy and increased fiber density are common in patients with fecal incontinence. Fiber density but not pudendal nerve terminal motor latency was correlated with clinical and manometric variables. The severity of nerve injury correlated with anal motor and sensory function in patients with neurogenic or idiopathic incontinence. The routine use of pudendal nerve terminal motor latency in the assessment of patients with fecal incontinence can be questioned.Read at The American Society of Colon and Rectal Surgeons' 100th Anniversary and Tripartite Meeting, Washington, D.C., May 1 to 6, 1999.     

Sacral Nerve Stimulation is more Effective than Optimal Medical Therapy for Severe Fecal Incontinence: A Randomized,Controlled Study

Purpose This randomized study was designed to compare the effect of sacral neuromodulation with optimal medical therapy in patients with severe fecal incontinence. Methods Patients (aged 39–86 years) with severe fecal incontinence were randomized to have sacral nerve stimulation (SNS group; n = 60) or best supportive therapy (control; n = 60), which consisted of pelvic floor exercises, bulking agent, and dietary manipulation. Full assessment included endoanal ultrasound, anorectal physiology, two-week bowel diary, and fecal incontinence quality of life index. The follow-up duration was 12 months. Results The sacral nerve stimulation group was similar to the control group with regard to gender (F:M = 11:1 vs. 14:1) and age (mean, 63.9 vs. 63 years). The incidence of a defect of ≤ 120° of the external anal sphincter and pudendal neuropathy was similar between the groups. Trial screening improved incontinent episodes by more than 50 percent in 54 patients (90 percent). Full-stage sacral nerve stimulation was performed in 53 of these 54 “successful” patients. There were no septic complications. With sacral nerve stimulation, mean incontinent episodes per week decreased from 9.5 to 3.1 (P < 0.0001) and mean incontinent days per week from 3.3 to 1 (P < 0.0001). Perfect continence was accomplished in 25 patients (47.2 percent). In the sacral nerve stimulation group, there was a significant (P < 0.0001) improvement in fecal incontinence quality of life index in all four domains. By contrast, there was no significant improvement in fecal continence and the fecal incontinence quality of life scores in the control group. Conclusions Sacral neuromodulation significantly improved the outcome in patients with severe fecal incontinence compared with the control group undergoing optimal medical therapy. *Deceased. Read at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, June 2 to 6, 2007.     

Double-blind crossover study of sacral nerve stimulation for fecal incontinence

PURPOSE: Patients with fecal incontinence not amenable to simple repair may have to undergo major reconstructive surgery or resort to a stoma. Sacral nerve stimulation is an alternative approach that may diminish incontinence by altering sphincter and rectal motor function. This study is the first double-blind trial examining the effectiveness of this therapy. METHODS: Two patients with passive fecal incontinence who had been implanted for nine months with a permanent sacral nerve stimulator and electrode were studied using fecal incontinence diaries, anorectal physiological tests, and quality-of-life assessments (SF-36 health survey). The trial period consisted of two two-week periods, with the stimulator turned on for two weeks and off for two weeks. The main investigator and the patients were blinded to the status of the stimulator. RESULTS: There was a dramatic difference between the number and severity of episodes of incontinence when the stimulator was turned onvs. turned off (Patient 1, 20vs. 2 episodes; Patient 2, 4vs. 0 episodes; offvs. on). There was an increase in squeeze pressure (Patient 1, 70vs. 100 cm H₂O; Patient 2, 60vs. 90 cm H₂O; offvs. on), with moderate increases in resting pressure and rectal threshold and urge volumes. Quality-of-life measurements showed a marked improvement prestimulationvs. nine months after permanent stimulation. CONCLUSIONS: There is a marked, unequivocal improvement in symptoms of fecal incontinence with sacral nerve stimulation shown in this double-blind crossover trial. Sacral nerve stimulation improves the quality of life in selected patients with fecal incontinence.A grant and all the equipment used in this study were supplied by Medtronic INTERSTIM, Maastricht, the Netherlands.     

Short-term sacral nerve stimulation for functional anorectal and urinary disturbances: results in 40 patients: evaluation of a new option for anorectal functional disorders

PURPOSE: There are several options in the treatment of fecal incontinence; it is often difficult to choose the most appropriate, adequate treatment. The consolidated experience gained in the urologic field suggests that sacral nerve stimulation may be a further option in the choice of treatment. The aim of our study was to evaluate the preliminary results of the peripheral nerve evaluation test obtained in a multicenter collaborative study on patients with defecatory and urinary disturbances. METHODS: Forty patients (9 males; mean age, 50.2; range, 26–79 years) underwent the peripheral nerve evaluation test, 28 (70 percent) for fecal incontinence and 12 (30 percent) for chronic constipation. Fourteen (35 percent) patients also had urinary incontinence; six had urge incontinence, two had stress incontinence, and six had retention incontinence. Associated diseases were scleroderma (2 patients), spinal injuries (4 patients), and syringomyelia (1 patient). All the patients underwent preliminary investigations with anorectal manometry, pudendal nerve terminal motor latency testing, anal ultrasound, defecography, and if required, urodynamic tests. The electrode for sacral nerve stimulation was positioned percutaneously under local anesthesia in the S2 (4), S3 (34), or S4 (1) foramen unilaterally (1 patient not accounted for because of no response to acute test), based on the best motor and subjective responses of paresthesia of the pelvic floor. Stimulation parameters were average amplitude, 2.8 (range, 1–6) V and average frequency, 15 to 25 Hz. RESULTS: The mean duration of the tests was 9.9 (range, 7–30) days; tests lasting fewer than seven days were not evaluated. There were four early displacements of the electrode. In 22 of the 25 evaluable patients with fecal incontinence, there was an improvement of symptoms (88 percent), and 11 (44 percent) were completely continent to liquid or solid stools, whereas in 7 symptoms were unchanged. Mean number of episodes of liquid or solid stool incontinence per week was 8.1 (range, 4–18) in the prestimulation period and 1.7 (range, 0–12) during the peripheral nerve evaluation test. (P=0.001; Wilcoxon's signed-rank test). The most important manometric findings were: increase of maximum rest pressure (39.4 ± 7.3vs. 54.3 ± 8.5 mmHg;P=0.014, Wilcoxon's test) and maximum squeeze pressure (84.7 ± 8.8vs. 99.5 ± 1.1 mmHg;P=0.047), reduction of initial threshold (63.6 ± 5.2vs. 42.4 ± 4.7 ml;P=0.041) and urge sensation (123.8 ± 0.6vs. 78.3 ± 8.9 ml;P=0.05). An improvement was also found in patients with constipation, with reduction in difficulty emptying the rectum, with prestimulation at 7 (range, 2–21) episodes per week and end of peripheral nerve evaluation test at 2.1 (range, 0–6) episodes per week, (P<0.01) and in the number of unsuccessful visits to the toilet, which dropped from 29.2 (7–24) to 6.7 (0–28) per week (P=0.01). The most important manometric findings in constipated patients were an increase in amplitude of maximum squeeze pressure during sacral nerve stimulation (prestimulation, 63 ± 0 mm Hg; end of peripheral nerve evaluation test, 78 ± 1 mm Hg;P=0.009) and a reduction in rectal volume for urge threshold (prestimulation, 189 ± 52 ml; end of peripheral nerve evaluation test, 139 ± 45 ml;P= 0.004). CONCLUSIONS: In functional bowel disorders short-term sacral nerve stimulation seems to be a useful diagnostic tool to assess patients for a minor invasive therapy alternative to conventional surgical procedure.Read at the meeting of The American Society of Colon and Rectal Surgeons, Boston, Massachusetts, June 24 to 29, 2000.     

Effects of magnetic sacral root stimulation on anorectal pressure and volume

PURPOSE: Electrical sacral root stimulation induces defecation in spinal cord injury patients and is currently under examination as a new therapy for fecal incontinence. In contrast to electrical stimulation, magnetic stimulation is noninvasive. To gain more insight into the mechanism of action of sacral root stimulation, we studied the effects of magnetic sacral root stimulation on anorectal pressure and volume in both fecal incontinence and spinal cord injury patients. METHODS: Three groups were examined: 14 healthy volunteers, 18 fecal incontinence patients, and 14 spinal cord injury patients. Repetitive magnetic sacral root stimulation was performed bilaterally using bursts of five seconds at 5 Hz. Anal and rectal pressure changes and rectal volume changes were measured. RESULTS: An increase in anal pressure was seen in 100 percent of the control subjects, in 86 percent of the spinal cord injury patients, and in 73 percent of the fecal incontinence patients (P=0.03). The overall median pressure rise after right-sided and left-sided stimulation was 12 (interquartile range, 8–18.5) and 13 (interquartile range, 6–18) mmHg at the mid anal level. A decrease in rectal volume was provoked in 72 percent of the control subjects, in 79 percent of the spinal cord injury patients, and in 50 percent of the fecal incontinence patients. Overall median volume changes after right-sided and left-sided stimulation were 10 (range, 5–22) and 9 (range, 5–21) percent from baseline volume. An increase in rectal pressure could be measured in 56 percent of the control subjects, 77 percent of the fecal incontinence patients, and 43 percent of the spinal cord injury patients. Median pressure rises after right-sided and left-sided stimulation were 5 (range, 3–12) and 5 (range, 3–5) mmHg. CONCLUSIONS: Magnetic sacral root stimulation produces an increase in anal and rectal pressure and a decrease in rectal volume in healthy subjects and patients with fecal incontinence or a spinal cord injury.Read at the XVIII Biennial Congress of The International Society of University Colon and Rectal Surgeons, São Paulo, Brazil, July 23 to 27, 2000.     

Sacral Nerve Stimulation for Fecal Incontinence Related to Obstetric Anal Sphincter Damage

Purpose Sphincter repair is the standard treatment for fecal incontinence secondary to obstetric external anal sphincter damage; however, the results of this treatment deteriorate over time. Sacral nerve stimulation has become an established therapy for fecal incontinence in patients with intact sphincter muscles. This study investigated its efficacy as a treatment for patients with obstetric-related incontinence. Methods Fecally incontinent patients with external sphincter defects who would normally have undergone overlapping sphincter repair as a primary or repeat procedure were included. Eight consecutive women (median age, 46 (range, 35–67) years) completed temporary screening; all eventually had permanent implantation. Results Six of eight patients had improved continence at median follow-up of 26.5 (range, 6–40) months. Fecal incontinent episodes improved from 5.5 (range, 4.5–18) to 1.5 (range, 0–5.5) episodes per week (P = 0.0078). Urgency improved in five patients, with ability to defer defecation improving from a median of <1 (range, 0–5) minute to 1 to 5 (range, 1 to >15) minutes (P = 0.031, all 8 patients). There was no change in anal manometry or rectal sensation. There was significant improvement in lifestyle, coping/behavior, depression/self-perception, and embarrassment as measured by the American Society of Colon and Rectal Surgery fecal incontinence quality of life score. Conclusions Sacral nerve stimulation is potentially a safe and effective minimally invasive treatment for fecal incontinence in patients with de novo external anal sphincter defects or defects after unsuccessful previous external anal sphincter repair, although numbers remain small. Dr. Michael Kamm is a consultant to and received research support from Medtronic, however, study design, performance, analysis, and reporting have been conducted without the influence of Medtronic.     

Sphincteroplasty for fecal incontinence in the era of sacral nerve modulation

The role of sphincteroplasty in the treatment of patients with fecal incontinence due to anal sphincter defects has been questioned because the success rate declines in the long-term.A new emerging treatment for fecal incontinence,sacral nerve stimulation,has been shown to be effective in these patients.However,the success rate of sphincteroplasty may depend of several patient-related and surgical-related factors and the outcome from sphincteroplasty has been evaluated differently(with qualitative data) fro...