Effect Of Sacral Nerve Stimulation Research Articles

Short- and Long-term Effectiveness of Sacral Nerve Stimulation in Patients with Overactive Bladder

BACKGROUND: Sacral nerve stimulation (SNS) approved for use in North America since 1997 despite the fact that the concept of using SNS to treat patients with voiding dysfunction discussed first almost 50 years ago.
 AIM: The objectives of the study were to assess the effectiveness of SNS the short and long term for patients with overactive bladder (OAB) dysfunction and its relation to age, gender, and causes.
 PATIENTS AND METHODS: This is a clinical prospective study that involved 50 cases (32 females and 18 males) with OAB. It was carried out at Ibn Sina Hospital, and the neurosciences hospital in Baghdad/Iraq from April 2015 to April 2018. All the patients were assessed preoperatively and certain inclusion criteria were used. The patients went through the 2 stage implantations of the Medtronic InterStim®. The patients were assessed at 6 months (short term) and 2 years (long term) postoperatively.
 RESULTS: The results of our patients were analyzed with respect to age, gender, causes of OAB, and post-operative complications. We found that younger age patients, female patients, and patients with neurogenic causes of OAB showed a better response in both the short- and long-term follow-up.
 CONCLUSION: Considerable progress has been made in the surgical management of OAB. Proper selection of patients is the key to the success of SNS, and female patients have better results compared to male patients. Furthermore, younger patients and patients with neurogenic causes did better than older patients and patients with idiopathic causes. SNS is a safe minimally invasive surgery with a low complication rate, and the 2 stages procedure has better results than the percutaneous nerve evaluation.

Sacral nerve stimulation increases gastric accommodation in rats: a spinal afferent and vagal efferent pathway.

Impaired gastric accommodation (GA) has been frequently reported in various gastrointestinal diseases. No standard treatment strategy is available for treating impaired GA. We explored the possible effect of sacral nerve stimulation (SNS) on GA and discovered a spinal afferent and vagal efferent mechanism in rats. Sprague-Dawley rats (450-500 g) with a chronically implanted gastric cannula and ECG electrodes were studied in a series of sessions to study: 1) the effects of SNS with different parameters on gastric tone, compliance, and accommodation using a barostat device; two sets of parameters were tested as follows: parameter 1) 5 Hz, 500 µs, 10 s on 90 s off; 90% motor threshold and parameter 2) same as parameter 1 but 25 Hz; 2) the involvement of spinal afferent pathway via detecting c-fos immunoreactive (IR) cells in the nucleus of the solitary tract (NTS) of the brain; 3) the involvement of vagal efferent activity via the spectral analysis of heart rate variability derived from the ECG; and 4) the nitrergic mechanism, Nω-nitro-l-arginine methyl ester (l-NAME), a nitric oxide synthase (NOS) inhibitor, was given before SNS at 5 Hz. Compared with sham-SNS: 1) SNS at 5 Hz inhibited gastric tone and increased gastric compliance and GA. No difference was noted between the stimulation frequencies of 5 and 25 Hz. 2) SNS increased the expression of c-fos in the NTS. 3) SNS increased cardiac vagal efferent activity and decreased the sympathovagal ratio. 4) l-NAME blocked the relaxation effect of SNS. In conclusion, SNS with certain parameters relaxes gastric fundus and improves gastric accommodation mediated via a spinal afferent and vagal efferent pathway.NEW & NOTEWORTHY Currently, there is no adequate medical therapy for impaired gastric accommodation, since medications that relax the fundus often impair antral peristalsis and thus further delay gastric emptying that is commonly seen in patients with functional dyspepsia or gastroparesis. The advantage of the potential sacral nerve stimulation therapy is that it improves gastric accommodation by enhancing vagal activity, and the enhanced vagal activity would lead to enhanced antral peristalsis rather than inhibiting it.

The effect of sacral nerve stimulation for chronic constipation

慢性便秘（CC）是消化道常见病，严重影响患者生活质量，发病率有逐年升高的趋势。骶神经刺激（SNS）为CC治疗选择之一，相比外科手术，操作更简单、并发症少，但其长期疗效及安全性仍存在争议，文中就新兴的SNS治疗不同类型CC患者的疗效及安全性进行综述。.

Effectiveness of sacral nerve stimulation in fecal incontinence after multimodal oncologic treatment for pelvic malignancies: a multicenter study with 2-year follow-up.

To assess whether sacral nerve stimulation (SNS) is an effective treatment for severe fecal incontinence (FI) after radiotherapy (RT)/chemoRT (CRT) in combination with pelvic surgery. A multicenter study was conducted on patients with FI that developed after multimodal therapy for pelvic tumors and was refractory to non-operative management, who were treated with SNS between November 2009 and November 2012. Data were prospectively collected and retrospectively analyzed. Cleveland Clinic FI score (CCFIS), FI episodes per week, FI Quality of Life (FIQoL), anorectal manometry and pudendal nerve terminal motor latency were evaluated before and after SNS. Eleven patients (seven females, mean age 67.3±4.8years) were evaluated in the study period. Multimodal treatments included surgery and CRT (four rectal, two cervical and one prostate cancers), surgery and RT (one cervical and two endometrial cancers) and CRT (one anal cancer). The mean radiation dose was 5.3Gy, and mean interval between the end of RT and onset of FI was 43.7±23months. Before SNS, the mean CCFIS and the mean number of FI episodes per week were 15.7±2.8 and 12.3±4.2, respectively. At 12-month follow-up, mean CCFIS improved to 3.6±1.8 (p=0.003) and the mean number of FI episodes decreased to 2.0±1.9 per week (p=0.003). These results persisted at 24-month follow-up. Significant improvement was also observed for each of the four domains of FIQoL at 12- and 24-month follow-up. Anorectal manometry values did not change significantly at follow-up. SNS is feasible and may be an effective therapeutic option for FI after multimodal treatment of pelvic malignancies.

Effects of sacral nerve stimulation on postpartum urinary retention-related changes in rat bladder

ObjectiveTo examine the effect of sacral nerve stimulation (SNS) on the urodynamic function and molecular structure of bladders in rats following acute urinary retention (AUR) after parturition. Material and methodsThirty primiparous rats were divided into three groups: postpartum, postpartum+AUR, and postpartum+AUR+SNS. AUR was achieved by clamping the distal urethra of a rat for 60 minutes. The postpartum+AUR+SNS group received electrical stimulation 60 minutes daily for 3 days after AUR. In addition to cystometric studies and external urethral sphincter electromyography, the expression of caveolins and nerve growth factor (NGF) and caveolae number in bladder muscle were analyzed. ResultsThe postpartum+AUR group has significantly greater residual volume than the postpartum group, but the residual volume decreased significantly after SNS treatment. The postpartum+AUR group had significantly lower peak voiding pressure, a longer bursting period and lower amplitude of electromyograms of external urethral sphincter activity than the postpartum and postpartum+AUR+SNS groups. The postpartum+AUR rats had higher NGF expression, lower caveolin-1 expression, and fewer caveolae in bladder muscle compared with the postpartum rats. Conversely, the caveolin-1 expression and caveolae number increased, and the NGF expression decreased after SNS treatment. ConclusionBladder dysfunction after parturition in a rat model caused by AUR may be restored to the non-AUR structural and functional level after SNS treatment.

Lack of effect of sacral nerve stimulation for incontinence in patients with systemic sclerosis.

Systemic sclerosis (SSc) is a multisystem disorder of unknown aetiology leading to the deposition of excessive connective tissue in the skin, blood vessels and internal organs. Gastrointestinal involvement occurs in 90% of cases and the prevalence of faecal incontinence (FI) is 38%. This study comprises the largest case series assessing the efficacy of sacral nerve stimulation (SNS) treatment for incontinence in this patient group. A retrospective analysis on prospectively collected data was performed on all SSc patients from our two centres who had undergone SNS for FI. Ten female patients of mean age of 54 (37-72) years had temporary SNS performed. The mean duration of FI was 13 (2-25) years. All had passive FI. Each patient had preprocedure anorectal physiology and endoanal ultrasound examinations documenting internal sphincter atrophy/fragmentation or reduced anal resting pressure. Overall there was no statistically significant difference (P = 0.57) in the total Wexner incontinence scores before (mean 15.1 ± 2.6 SD) and during temporary SNS procedures (mean 13.1 ± 3.6 SD). Two patients with a significant improvement went on to have permanent SNS with only one achieving a favourable outcome at 1 year. This study showed that SNS failed to reduce episodes of leakage in nine out of 10 patients with systemic sclerosis affected with incontinence.

Sacral Nerve Stimulation Is an Effective Treatment Strategy in Refractory Fecal Incontinence (FI)

Introduction: Fecal incontinence (FI) is a prevalent, underreported, and socially devastating condition. Currently, there are few effective treatment strategies. Some studies have shown that sacral nerve stimulation with the InterStim device is beneficial in controlling urinary incontinence. While conservative therapy (including fiber supplementation, bulking agents, pelvic floor physical therapy with biofeedback) has been shown to have meager to modest benefit in management of FI, some studies have suggested variable success rates of sacral nerve stimulation in FI. Our primary aim was to evaluate the effectiveness of sacral nerve stimulation among FI patients who have failed other treatment modalities. Methods: We reviewed consecutive patients who were referred to colorectal surgery from January 2012 to July 2013 for evaluation of refractory FI and consideration of InterStim device implantation. All patients who met criteria for implantation had a temporary device placed for a 2 week trial and only if they experienced symptom improvement, was a permanent device placed. All patients completed symptom improvement forms at their 4 week follow-up visit. Results: Sixteen patients total were referred to colorectal surgery for refractory FI and had InterStim device implantation. All patients were initially treated with conservative measures, and 2 patients had an overlapping sphincteroplasty without any appreciable benefit. Among the 16, 14 reported benefit ranging from 50-100% improvement in symptoms, while only 2 had no improvement and had the temporary stimulator removed (87.5% vs 12.5%, p<0.0001). Logistic regression analysis was performed and did not show significant differences in age, gender, or race in predicting treatment response to sacral nerve stimulation. Conclusion: The management of FI remains challenging with limited therapeutic options available presently. Our results show that refractory FI patients who fail to improve with conservative measures can improve with sacral nerve stimulation using the InterStim device, suggesting a role for device placement in those patients who fail to respond to conservative measures. Large-scale, prospective studies are needed to further delineate the efficacy of sacral nerve stimulation using the InterStim device in this population.

Author's reply: The effect of sacral nerve stimulation on distal colonic motility in patients with faecal incontinence (Br J Surg 2013; 100: 959–968)

Author's reply: The effect of sacral nerve stimulation on distal colonic motility in patients with faecal incontinence (<i>Br J Surg</i> 2013; 100: 959–968)

The effect of sacral nerve stimulation on distal colonic motility in patients with faecal incontinence (Br J Surg 2013; 100: 959–968)

Abstract The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.

The effect of sacral nerve stimulation on distal colonic motility in patients with faecal incontinence

Sacral nerve stimulation (SNS) is an effective treatment for neurogenic faecal incontinence (FI). However, the clinical improvement that patients experience cannot be explained adequately by changes in anorectal function. The aim of this study was to examine the effect of SNS on colonic propagating sequences (PSs) in patients with FI in whom urgency and incontinence was the predominant symptom. In patients with FI a high-resolution fibre-optic manometry catheter, containing 90 sensors spaced at 1-cm intervals, was positioned colonoscopically and clipped to the caecum. A unipolar or quadripolar tined electrode was implanted into the S3 sacral nerve foramen. Colonic manometry was evaluated in a double-blind randomized crossover trial, using true suprasensory stimulation or sham stimulation. Each stimulation period, lasting 2 h, was preceded by a 2-h basal manometric recording. All 11 patients studied showed a colonic response to SNS. In ten patients there was a significant increase in the frequency of retrograde PSs throughout the colon during true stimulation compared with sham stimulation (P = 0·014). In one outlier, with baseline retrograde PS frequency nine times that of the nearest patient, a reduction in retrograde PS frequency was recorded. Compared with sham stimulation, SNS had no effect on the frequency of antegrade PSs or high-amplitude PSs. SNS modulates colonic motility in patients with faecal urge incontinence. These data suggest that SNS may improve continence and urgency through alteration of colonic motility, particularly by increasing retrograde PSs in the left colon.

Sacral Nerve Stimulation for Fecal Incontinence Related to External Sphincter Atrophy

Atrophy of the external anal sphincter, a pathologic muscle volume anomaly associated with fecal incontinence, has been shown to be a negative predictor of the outcome of surgery for defects of the external anal sphincter. It is unclear whether external anal sphincter atrophy also affects the outcome of sacral nerve stimulation for fecal incontinence. Our aim was to assess the effectiveness of sacral nerve stimulation in patients with fecal incontinence and external anal sphincter atrophy and to determine whether severity of atrophy and concomitant presence of a sphincter defect are negative predictors of outcome. This was a prospective observational study of treatment outcome. The study was conducted from November 2004 through November 2010 at a regional hospital in Italy. Consecutive patients with fecal incontinence and external anal sphincter atrophy were included. By means of MRI, patients were determined to have either moderate (<50%) or severe (≥ 50%) thinning of and/or replacement of sphincter muscle by fat. The concomitant presence of defects of the external anal sphincter was also detected by MRI. All patients underwent sacral nerve stimulation through a staged implantation procedure. The main outcome measures were improvement in the Cleveland Clinic Florida Fecal Incontinence Scale (Wexner score), number of episodes of incontinence per week, and the Fecal Incontinence Quality of Life Scale. A total of 28 patients underwent definitive implantation of the sacral nerve stimulation device. Wexner scores decreased from a median of 16 (range, 10-20) at baseline to 3 (range, 0-8) at 6-month follow-up (p < 0.001). Weekly incontinence episodes decreased from a mean (SD) of 14.7 (12.5) to 0.40 (0.82); p < 0.001. Improvement was significantly related to severity of fecal incontinence (r = 0.86; p < 0.001). Overall quality-of-life scores improved from a mean of 1.8 (0.6) to 3.8 (0.4);p < 0.001. Sacral nerve stimulation was effective in both moderate (n = 16) and severe (n = 12) atrophy and in patients with (n = 8) or without (n = 20) external anal sphincter defects. The study was limited by its observational nature and relatively small sample size. Sacral nerve stimulation can be effective in restoring continence and improving quality of life in patients with fecal incontinence related to atrophy of the external anal sphincter, regardless of the severity of atrophy. Moreover, the presence of EAS atrophy does not influence the success of the outcome of SNS in patients with a sphincter defect. These findings are consistent with the hypothesis that the effects of SNS are not achieved solely by its action on the anal sphincter complex.

Temporary Sacral Nerve Stimulation Alters Rectal Sensory Function: A Physiological Study

The indications for sacral nerve stimulation are increasing, but the mechanism remains poorly understood. This study aimed to examine the effect of sacral nerve stimulation on rectal compliance and rectal sensory function. This was a prospective study. This study took place at a university teaching hospital. Twenty-three consecutive consenting patients (22 female; median age, 49 y) undergoing temporary sacral nerve stimulation for fecal incontinence were prospectively studied. Clinical response was assessed by the use of bowel diaries and Wexner scores. Anal manometry, rectal compliance, volume and pressure thresholds to rectal distension (barostat), and rectal Doppler mucosal blood flow were measured before and at the end of stimulation. Sixteen patients (70%) had a favorable clinical response. Median anal squeeze pressures increased with stimulation from 40 (range, 6-156) cmH2O to 64 (range, 16-243) cmH2O. Median rectal compliance did not significantly change with stimulation (prestimulation: 11.5 (range, 7.9-21.8) mL/mmHg, poststimulation: 12.4 (range, 6.2-22) mL/mmHg, P = .941). Rectal wall pressures associated with urge (baseline: 15.4 (range, 11-26.7) mmHg, poststimulation: 19 (range, 11.1-42.7) mmHg, P = .054) and maximal tolerated thresholds (baseline: 21.6 (8.5-31.9) mmHg, poststimulation: 27.1 (14.3-43.3) mmHg, P = .023) significantly increased after stimulation. Rectal Doppler mucosal blood flow did not significantly change with stimulation (baseline: 125.8 (69.9-346.8), poststimulation: 112.4 (50.2-404.1), P = .735). Changes in anal resting pressure and rectal wall pressures with stimulation were evident only in responders; however, changes in anal squeeze pressures were evident in both responders and nonresponders. The study reports results following short-term stimulation in a small but homogenous group of patients. A larger long-term study will follow. Temporary sacral nerve stimulation does not change rectal compliance, but is associated with significant changes to the pressure thresholds of rectal distension. This, together with the observation that outcome is not related to sphincter integrity, supports the hypothesis of an afferent-mediated mechanism of action.

The influence of sacral nerve stimulation on anorectal dysfunction

Sacral nerve stimulation (SNS) has become an established option in the management of defaecatory disorders. There are many data on the end-organ effects of SNS, but limited consensus on its mechanism of action. The objective of this review was to determine the effect of sacral nerve stimulation (SNS) on anorectal function. Systematic literature review of the effect of sacral nerve stimulation (SNS) on anorectal function. There was significant heterogeneity of data pertaining to the effects of SNS on anorectal function, with no consistent change in physiological measures identified. Most data supported a mixed mechanism of action on anal motor and rectal sensory functioning. To date, conflicting data exist on the mechanism of action of SNS as determined by end-organ changes in anorectal physiology. Nevertheless, the data as they stand best support a mixed mechanism of action on anal motor and rectal sensory functions.

Future indications for sacral nerve stimulation

The aim of this article was to determine the effect of sacral nerve stimulation (SNS) on the treatment of faecal incontinence, constipation, irritable bowel syndrome, mixed urinary and bowel disorders, spinal injury and neurodegenerative disease, pain syndromes, and sexual dysfunction. A Medline search was performed including the keywords and/or MeSH headings of 'sacral nerve stimulation', 'neuromodulation', 'artificial pacemaker', 'faecal incontinence', 'constipation' and 'anal pain'. Further studies were identified by cross-referencing from relevant articles and by appraisal of recent peer-reviewed conference abstracts and proceedings. SNS has been used for the treatment of urinary, bowel and sexual dysfunction, as well as pain resulting from such disorders, and dysfunction arising from nerve injury and degenerative disease. There is a paucity of high quality evidence to support the use of SNS for the majority of novel indications at present. Good quality prospective, cross-over studies are required to determine the true benefits of SNS. Further research into patient selection, operative technique and stimulation parameters for existing indications will ensure a place for SNS in the future treatment algorithm of functional pelvic floor disorders.

Sacral nerve stimulation for the treatment of faecal incontinence following low anterior resection for rectal cancer

The aim of this study was to assess the effectiveness of sacral nerve stimulation (SNS) in the management of faecal incontinence following neoadjuvant therapy and low anterior resection (LAR) for rectal cancer. In a prospective single-centre study, 15 patients (12 men, median age 72 years) were enrolled between 2005 and 2008. All had severe incontinence after total mesorectal excision, and 14 had received preoperative full-course chemoradiotherapy. The patients were followed up for a median of 50 (range: 24-144) months. There was no recurrence (local or distal). Incontinence was evaluated using the Cleveland Clinic Florida Fecal Incontinence (CCF-FI) scoring system. Quality of life (QoL) was evaluated using the Fecal Incontinence Quality of Life (FIQL) questionnaire. SNS was performed in three stages. During percutaneous nerve evaluation (PNE), a good response was observed in seven patients, all of whom received a permanent implant. The median follow up was 12 (range: 1-44) months. The mean CCF-FI score was reduced from 19.2 [standard deviation (SD) 1.2] to 6.2 (SD 1.7) (P < 0.01). The mean number of days per week with an incontinent episode decreased from 7 (SD 0) to 0.2 (SD 0.3) (P < 0.01), and the mean number of defaecations per week decreased from 42.5 (SD 13.7) to 13.2 (SD 7.4) (P < 0.01). In the five patients with a permanent implant who were followed up for longer than 6 months, all FIQL scores improved. An increase in the mean resting and squeeze pressures was seen in four patients with a permanent implant. SNS is a treatment option for faecal incontinence after LAR for rectal cancer.

Satisfaction and Patient Experience With Sacral Neuromodulation: Results of a Single Center Sample Survey

We systematically assessed long-term satisfaction and patient experience with sacral nerve modulation therapy. All patients who received sacral neuromodulation between 1990 and 2007 at our center and who still had the implant were included in the survey. All received a postal questionnaire regarding satisfaction and experiences with the system, such as side effects, complications, burden, impact on sexuality and defecation changes. Of the 275 questionnaires sent 207 were returned for a 75% response rate. The population was 83% female. Overall treatment was done for overactive bladder syndrome, nonobstructive urinary retention, combined overactive bladder and retention, and pelvic pain in 55%, 24%, 20% and 1% of patients, respectively. Overall satisfaction with sacral neuromodulation was high at 90%. No correlations were found between the satisfaction rate, and pretreatment age, gender, complaint type, sexual dysfunction or therapy duration. However, 56% of patients reported side effects, such as pain at the internal nerve stimulator site and due to stimulation. However, 89% of these patients did not seek further therapy. Of patients with additional defecation problems 47% experienced relief of complaints. This study shows a high satisfaction rate in patients with sacral neuromodulation. There was no relation between patient age, complaint type, therapy duration or side effects and the satisfaction rate. The number of side effects was limited but further analysis in prospective cohorts should identify patients who are likely to have side effects or stop sacral neuromodulation treatment.

Sacral Neuromodulation in Children With Urinary and Fecal Incontinence: A Multicenter, Open Label, Randomized, Crossover Study

The clinical benefit of sacral neuromodulation is unclear due to the paucity of randomized trial data. The purpose of this study was to evaluate sacral neuromodulation for management of urinary and fecal incontinence in a pediatric population. This multicenter, open label, randomized, crossover study included children older than 5 years. After trial stimulation of the S3 root a neuromodulator (InterStim) was implanted on the S3 foramen. Clinical examinations, voiding and bowel diaries, and urodynamic and manometric evaluations were performed at the beginning (t1) and end (t2) of the first period, and at the beginning (t3) and end (t4) of the second period. A total of 33 patients (24 boys) with a mean +/- SD age of 12.22 +/- 5.09 years were randomized. Etiologies were mainly of neurological origin. Incontinence was mixed urinary and fecal in 19 cases, urinary only in 9 and fecal only in 5. Cystometric bladder capacity increased during sacral neuromodulation (delta +24.27 ml vs -37.45 ml, p = 0.01). There was no significant change in other urodynamic or manometric parameters. Overall positive response rate was more than 75% for urinary (81%) and bowel (78%) function. Crossover analysis indicated that sacral neuromodulation is more effective than conservative treatment for both types of incontinence (p = 0.001). In a pediatric population sacral neuromodulation is effective for bladder and bowel dysfunction and should be considered before irreversible surgery.

The Effect of sacral nerve stimulation on uterine activity: a pilot study

Sacral nerve stimulation (SNS) is a treatment for consecutive therapy resistant faecal incontinence or constipation. Little is known about the effects of SNS on uterocervical function. Therefore, it is advised to turn off the stimulator during pregnancy or to wait with permanent implantation of the stimulator until family completion. Diagnostic ultrasound provides an, non-invasive, opportunity to study various aspects of uterine activity. The purpose of this pilot study was to assess the influence of SNS on endometrial waves of the nonpregnant uterus by ultrasound recordings. Six patients with an implanted SNS were included. Ultrasound recordings were performed with the stimulator turned off and in three stimulation frequencies. Uterine activity is described as wave frequency and wave direction. All three premenopausal patients showed endometrial activity with the stimulator turned off. This activity was maintained with the stimulator turned on in two patients, but disappeared in one patient. All three postmenopausal patients had no endometrial activity with the stimulator turned off. In one patient there was activity with the stimulator turned on at a frequency of 21 Hz. We have shown some effect of SNS on uterine activity. In premenopausal women we discovered that SNS seems to exhibit no effect or an inhibitory effect rather than an excitatory effect on uterine activity. Based on the preliminary results of this study, we can not recommend any guidelines for SNS usage during conception and pregnancy. A larger study in premenopausal women with SNS is needed to investigate the significance of these changes.

Clinical and cost effectiveness of sacral nerve stimulation for faecal incontinence

Sacral nerve stimulation (SNS) has better results and safety than other surgical procedures for faecal incontinence. This prospective study assessed the clinical effectiveness and costs of SNS at a single centre. Patients who had experienced one or more episodes of faecal incontinence were studied for up to 5 years by continence diary, anorectal manometry and quality of life questionnaires. Direct medical costs were calculated and the cost-effectiveness of the treatment was analysed. Fifty-seven percutaneous nerve evaluations were performed in 47 patients between June 1999 and February 2006; 29 patients underwent permanent implantation. After a median follow-up of 34.7 (range 2.3-81.2) months, 25 of the 29 patients had a significant reduction in incontinence episodes; 14 patients were in complete remission. At 3-year follow-up, the mean reduction in incontinence episodes was 89 per cent. No change was observed in anal manometric values. Patients reported a significant improvement in quality of life. The introduction of SNS has an incremental cost-effectiveness ratio, below the accepted Spanish threshold. The introduction of SNS to the management of faecal incontinence within the Spanish setting is both effective and efficient.

Sacral Nerve Stimulation for Fecal Incontinence: External Anal Sphincter Defect vs . Intact Anal Sphincter

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. 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. The external anal sphincter defect group (defect <90 degrees:defect 90 degrees-120 degrees = 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. 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 degrees of circumference.