Medical Policy: 08.01.21
Original Effective Date: September 2013
Reviewed: June 2018
Revised: June 2018
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
The brain communicates with the body by sending electrical signals along nerves. When it comes to going to the bathroom, the brain sends signals to specific nerves that travel through the lower back to the muscles that control the opening and closing of the bladder and bowel. Weak electrical signals may be used to address certain kinds of bladder and bowel problems that have not responded to other treatment. This procedure is known as sacral nerve stimulation (SNS), also known as sacral nerve neuromodulation (SNM). This procedure involves the implantation of a small device an implantable pulse generator (in the individual's lower abdomen) that delivers controlled electrical impulses. This pulse generator is attached to wire leads that connect to the sacral nerves, most commonly the S3 nerve root. Two external components of the system help control the electrical stimulation. A control magnet, kept by the patient is used to turn the device on or off. A console programmer is kept by the physician and used to adjust the settings of the pulse generator. This treatment usually is done in two steps. The first step is a temporary placement to find out if sacral nerve stimulation works. The second is the surgery to place the permanent implant.
Treatment using sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM), is one of several alternative modalities for patients with fecal or urinary incontinence (urge incontinence, urgency-frequency syndrome, nonobstructive urinary retention or overactive bladder) who have a documented failure or intolerance to conventional conservative therapies (behavior training such as bladder training, promoted voiding, pelvic muscle exercise training; dietary modification; and pharmacologic therapies).
Urinary voiding dysfunction is usually defined as the inability to control urination and are divided into different types:
Treatment options for urinary voiding disorders may include behavioral strategies, pharmacological interventions, electrical stimulation or reconstructive surgery.
Fecal incontinence is the inability to control bowel movements leading to feces leaking from the rectum. Fecal incontinence may be caused by several factors including muscle damage, such as that experienced by childbirth, or after rectal surgery, or from damage to the nerves that control the anal muscle or regulate rectal sensation. Additionally, it may be caused by a reduction in the elasticity of the rectum, which shortens the time between the sensation of the stool and the urgent need to have a bowel movement. Surgery or radiation injury can scar and stiffen the rectum. Inflammatory bowel disease can also make the rectum less elastic.
Treatment depends on the cause of the incontinence and may include dietary changes, drug therapy, bowel training, sacral nerve stimulation or surgery.
Before implantation of the permanent device, patients undergo an initial trial testing phase to estimate potential response to treatment. The first type of testing developed was percutaneous nerve evaluation (PNE). This procedure is done under local anesthesia, using a test needle to identify the appropriate sacral nerve(s). Once identified, a temporary lead wire is inserted through the test needle and the wire is attached to an external stimulator, which is carried in the pocket or on a belt loop for a trial period of 4 to 7 days. The individual records voiding patterns during the trial period and for one week after the wire is removed. Data from the voiding diaries are used to compare the symptoms that are experienced at baseline, during the test phase, and after removal of the wire. The results of this test phase are used to determine whether patients are appropriate candidates for the permanent device. If the trial stimulation demonstrates the patient had 50% or greater reduction in symptom frequency, they are deemed eligible for the permanent device.
A second type of testing is a 2-stage surgical procedure. In the first stage, a quadripolar-tined lead is implanted (stage 1). The testing phase can last as long as several weeks, and if patients show a 50% or greater reduction in symptom frequency, they can proceed to stage 2 of the surgery, which is permanent implantation of the stimulation/neuromodulation device. The 2-stage surgical procedure has been used in various ways. They include its use instead of PNE (percutaneous nerve evaluation), for patients who fail PNE, for patients with an inconclusive PNE, or for patients who had a successful PNE to refine patient selection further.
The permanent device is implanted with the patient under general anesthesia. The electrical leads are placed in contact with the sacral nerve root(s) via an incision in the lower back, and the wire leads are extended through a second incision underneath the skin, across the flank to the lower abdomen where the pulse generator is inserted and connected to the wire leads. Following implantation, the physician programs the pulse generator to the optimal settings for the patient. The patient can switch the pulse generator on and off by placing the control magnet over the area of the pulse generator for 1 to 2 seconds.
Several RCTs on sacral nerve stimulation/neuromodulation (SNS/SNM) for urinary incontinence have been conducted. One was sponsored by Medtronic and submitted to the U.S. Food and Drug Administration as part of the device approval process. Findings have not otherwise been published. Based on this RCT, the authors concluded that SNS reduced urge incontinence compared with control patients. The trial was well-designed, using standardized clinical and functional status outcomes measurements, and enrolled patients with severe urge incontinence who had failed extensive prior treatments. The magnitude of effect (approximately one-half of patients became dry, three-quarters experienced at least 50% reduction in incontinence) was fairly large, probably at least as great as with surgical procedures, and larger than expected from a placebo effect or conservative measures such as behavioral therapy or drugs. The therapy evaluation test, in which the device was turned off (i.e., sham treatment was provided) and patients thus served as their controls, provided further evidence that the effect on incontinence was due to electrical stimulation and demonstrated that the effect of SNS is reversible. The cohort analysis of the clinical trial provided some evidence that the effect of SNS could be maintained for up to 2 years. There was a high rate of adverse events reported in this trial. Most were minor and reversible; however, approximately one-third of patients required surgical revision for pain at the operative sites or migration of the leads.
In this RCT, 177 of 581 patients had urinary retention. Patients with urinary retention reported significant improvements regarding volume per catheterization, a decrease in the number of catheterizations per day, and increased total voided volume per day. At 12 months post-implant, 61% of patients had ceased use of catheterization. At baseline, 220 (38%) of 581 had significant urgency-frequency symptoms. After 6 months, 83% of patients with urgency-frequency symptoms reported increased voiding volumes with the same or reduced degree of frequency. At 12 months, 81% of patients had reached normal voiding frequency. Compared with a control group, patients with implants reported significant improvements in quality of life (QOL), as evaluated by the Short-Form 36-Item Health Survey.
An additional prospective RCT of 44 patients with urge incontinence was published by Weil et. al.. At 6 months, the implant group showed significantly greater improvements in standardized clinical outcomes, compared with those receiving conservative therapy. The magnitude of effect was substantial.
Siegel et. al. (2015) published results of an industry-sponsored, Food and Drug Administration mandated a post-approval study known as the Insite trial. This RCT compared sacral nerve neuromodulation (SNM) using a 2-stage surgical procedure with standard medical therapy. Study inclusion criteria were a diagnosis of overactive bladder (at least 8 voids per day and/or at least 2 involuntary leaking episodes in 72 hours) and a failed trial of at least 1 anticholinergic or antimuscarinic medication. Also, there needed to be at least 1 such medication that had not yet been prescribed. Patients with neurologic diseases and with primary stress incontinence were excluded. Seventy patients were allocated to SNM and 77 to standard medical therapy. Of the 70 patients in the SNM group, 11 elected not to receive test stimulation with the tined lead and 8 received the lead but did not receive a full system implant due to lack of response to a 14-day test stimulation period (response was defined as ≥50% reduction in average leaks and/or voids). Patients in the medical treatment group tried the next recommended medication or restarted a discontinued medication. Therapeutic success was defined as at least a 50% improvement in average leaks per day or at least a 50% improvement in the number of voids per day or a return to fewer than 8 voids per day. In intention-to-treat (ITT) analysis, the therapeutic success rate at 6 months was 61% in the SNM group and 42% in the standard treatment group; the difference between groups was statistically significant (p=0.02). QOL at 6 months was a secondary outcome. Several validated QOL scales were used, and all favored the SNM group compared with the standard treatment group (p<0.002 for all comparisons).
Twelve-month follow-up of the Insite trial was published by Noblett et. al. (2016). They analyzed patients from in the sacral nerve stimulation (SNS) group of initial RCT plus additional patients enrolled and implanted in the interim. A total of 340 patients underwent test stimulation, 272 underwent implantation, and 255 completed 12 months of follow-up. In a modified completers’ analysis, the therapeutic success rate was 82%. This modified completers’ analysis included patients who were implanted and had either a baseline or 12-month evaluation or withdrew from the trial due to a device-related adverse event or lack of efficacy. In an analysis limited to study completers, the therapeutic response rate was 85%. The Noblett analysis did not include data from the control group of patients receiving only standard medical therapy.
Amundsen et. al. (2016) reported on an RCT comparing intradetrusor injection of onabotulinumtoxinA (n=192) with SNM (n=189) in women with refractory urgency urinary incontinence, defined as at least 1 supervised behavioral or physical therapy intervention and the use of a minimum of 2 anticholinergics (or inability to tolerate or contraindications to the medication). In ITT analysis, patients in the onabotulinumtoxinA-treated group had greater reductions in urge incontinence per day (3.9 per day) than in the SNM-treated group (3.3 per day; mean difference, 0.63; 95% confidence interval [CI], 0.13 to 1.14; p=0.01). OnabotulinumtoxinA-treated patients had greater reductions in some overactive bladder-related QOL questionnaire-related measures, although the clinical meaningfulness of the changes was uncertain. Patients in the onabotulinumtoxinA-treated group were more likely to have urinary tract infections (35% vs 11%; risk difference, -23%; 95% CI, -33% to -13%; p<0.001).
Case series have provided longer follow-up data than the RCTs. For example, a series by Groen et. al. (2011) in the Netherlands reported the longest follow-up. Sixty patients had at least 5 years of follow-up after SNM for refractory idiopathic urge urinary incontinence. Success was defined as at least a 50% decrease in the number of incontinent episodes or pads used per day. The success rate was 52 (87%) of 60 at 1 month and gradually decreased to 37 (62%) at 5 years. The number of women who were completely continent was 15 (25%) at 1 month and 9 (15%) at 5 years. At the 5-year follow-up, SNM was still used by 48 (80%) of 60 women. Fifty-seven adverse events were reported in 32 (53%) of 60 patients. The most frequent were hardware-related or pain or discomfort. There were 23 reoperations in 15 patients. In most cases, the pain was managed conservatively.
Findings from a large prospective series were reported by White et. al. (2009). The series focused on complications associated with SNM in 202 patients with urge incontinence, urinary urgency, or urinary retention. At a mean follow-up of 37 months (range, 7-84 months), 67 (30%) patients had experienced adverse events that required either lead or implantable pulse generator revisions. Complications included pain (3%), device malfunction secondary to trauma (9%), infection (4%), postoperative hematoma (2%), and lead migration (6%). Also, 5% of patients underwent elective removal, 4% had device removal due to lack of efficacy, and 2% required removal due to battery expiration. At the last follow-up, 172 (85%) patients had functional implanted units.
Data from randomized controlled trials (RCTs) and case series with long-term follow-up have suggested that sacral nerve stimulation/neuromodulation (SNS/SNM) reduces symptoms of urge incontinence, urgency-frequency syndrome, non-obstructive urinary retention and overactive bladder in selected patients.
Tan et. al. (2011) published a meta-analysis of studies sacral nerve neuromodulation (SNM) for treating fecal incontinence. They identified 34 studies that reported on at least 1 of their outcomes of interest and documented how many patients underwent temporary and permanent SNM. Only 1 study was an RCT (Tjandra et al ). In the 34 studies, 944 patients underwent temporary SNS, and 665 subsequently underwent permanent SNS implantation. There were 279 patients who did not receive permanent implantation, and 154 of them were lost to follow-up. Follow-up in the studies ranged from 2 to 35 weeks. In a pooled analysis of findings of 28 studies, there was a statistically significant decrease in the number of incontinence episodes per week with SNM compared with maximal conservative therapy (weighted mean difference, -6.83; 95% CI, -8.05 to -5.60; p<0.001). Fourteen studies reported incontinence scores, and when these results were pooled, there was also a significantly greater improvement in scores with SNS than with conservative therapy (weighted mean difference, -10.57; 95% CI, -11.89 to -9.24; p<0.001).
Maeda et. al. (2011) published a systematic review of studies on complications following permanent implantation of an sacral nerve stimulation (SNS) device for fecal incontinence and constipation. Reviewers identified 94 articles. Most addressed fecal incontinence. A combined analysis of data from 31 studies on SNS for fecal incontinence reported a 12% suboptimal response to therapy (149/1232 patients). A review of complications reported in the studies found that the most commonly reported complication was pain around the site of implantation, with a pooled rate of 13% (81/621 patients). The most common response to this complication was repositioning the stimulator, followed by device explantation and reprogramming. The second most common adverse event was an infection, with a pooled rate of 4% (40/1025 patients). Twenty-five (63%) of the 40 infections led to device explantation.
Thin et. al. (2013) published a systematic review of randomized trials and observational studies evaluating sacral nerve neuromodulation (SNM) for treating fecal incontinence. Sixty-one studies met the following eligibility criteria: assessed at least 10 patients, had a clear follow-up interval and reported the success rate of therapy based on a 50% or greater reduction in fecal incontinence episodes. Only 2 studies were RCTs (Tjandra et al , Leroi et al ; described next) and 50 were prospective case series. Data from 2 studies with long-term follow-up were pooled to calculate median success rates using ITT analysis. These median success rates were 63% in the short term (≤12 months of follow-up), 58% in the medium term (12-36 months), and 54% in the long-term (>36 months). The per-protocol short-, medium-, and long-term success rates were 79%, 80%, and 84%, respectively.
Thaha et. al. (2015) conducted a Cochrane review assessing sacral nerve stimulation (SNS) for fecal incontinence and constipation in adults, which included randomized, quasi-randomized, and crossover trials. For fecal incontinence, reviewers included 6 trials of SNM (n=219 patients), 2 of which used parallel-group designs (Thin et al , Tjandra et al ; the latter described below); the others used crossover designs. The primary methodologic quality issue noted was a lack of clarity involving randomization techniques and allocation concealment. Reviewers concluded: “The limited evidence from the included trials suggests that SNS can improve continence in a proportion of patients with fecal incontinence.”
Tjandra et. al. (2008) published an RCT assessing 120 patients with severe fecal incontinence. Patients were randomized to sacral nerve stimulation (SNS) or best supportive therapy, consisting of pelvic floor exercises with biofeedback, bulking agents, and dietary management with a team of dieticians. Exclusion criteria included neurologic disorders and external anal sphincter defects of more than 120° of the circumference, although a “high proportion” of the patients had pudendal neuropathy. The trial was not blinded. Of the 60 patients randomized to SNS, 54 (90%) had successful test stimulation and 53 proceeded with the implant of the pulse generator. At baseline, the SNS group had an average of 9.5 incontinent episodes per week, and the controls had 9.2. Both groups had an average of 3.3 days per week with incontinence. At 12-month follow-up, episodes had decreased to 1 day per week, with 3.1 episodes in the SNS group, but no change in the control group (mean, 3.1 d/wk), with 9.4 episodes. Complete continence was achieved in 22 (42%) of the 53 SNS patients and 13 (24%) patients improved by 75% to 99%. None of the patients had worsening of fecal continence. Adverse events included pain at implant site (6%), seroma (2%), and excessive tingling in the vaginal region (9%).
A key multicenter prospective trial is the 16-site multicenter Food and Drug Administration investigational device exemption study of SNS in 120 patients with fecal incontinence. Findings were initially reported by Wexner et. al. (2010). To be included, patients had to have chronic fecal incontinence for more than 6 months or more than 12 months after vaginal childbirth, defined as more than 2 incontinent episodes on average per week. All patients had failed or were not candidates for more conservative treatments. Exclusion criteria included congenital anorectal malformation; previous rectal surgery, if performed within the last 12 months (or 24 months in case of cancer); defects of the external anal sphincter over 60°; chronic inflammatory bowel disease; visible sequelae of pelvic radiotherapy; active anal abscesses and fistulae; neurologic diseases such as clinically significant peripheral neuropathy or complete spinal cord injury; and anatomic limitations preventing the successful placement of an electrode. A total of 285 patients were screened; 133 were enrolled and underwent acute test stimulation, and 120 showed at least 50% improvement during the test phase and received a permanent stimulator. Thirty-four of the 120 patients exited the study for various reasons both related (ie, lack of efficacy in 6, implant site infection or skin irritation in 5) and unrelated to the implant (ie, the death of a local principal investigator). Analysis based on the initial 133 patients showed a 66% success rate (≥50% improvement), while analysis based on 106 patients considered completed cases at 12 months showed an 83% success rate. The success rate based on the 120 patients who received a permanently implanted stimulator would fall between these 2 rates. Of 106 cases included in the 12-month results, perfect continence (100% improvement) was reported in approximately 40%, while an additional 30% of patients achieved 75% or greater reduction in incontinent episodes. Success was lower in patients with an internal anal sphincter defect (65% [n=20]) than in patients without a defect (87% [n=86]).
Three- and 5-year findings were subsequently published. Mellgren et. al. (2011) reported on the 120 patients who received a permanently implanted stimulator. Mean length of follow-up was 3.1 years, and 83 (69%) completed at least part of the 3-year follow-up assessment. In ITT analysis using the last observation carried forward, 79% of patients experienced at least a 50% reduction in the number of incontinent episodes per week compared with baseline, and 74% experienced at least a 50% reduction in the number of incontinent days per week. In a per-protocol analysis at 3 years, 86% of patients experienced at least a 50% reduction in the number of incontinent episodes per week, and 78% experienced at least a 50% reduction in the number of incontinent days per week. By the 3-year follow-up, 334 adverse events considered potentially device-related had been reported in 99 patients; 67% of these occurred within the first year. The most frequently reported adverse events among the 120 patients were implant site pain (28%), paresthesia (15%), implant site infection (10%), diarrhea (6%), and extremity pain (6%). Six infections required surgical intervention (5 device removals, 1 device replacement). Hull et al (2013) reported on outcomes in 72 patients (60% of the 120 implanted patients) who had completed a 5-year follow-up visit.18 Sixty-four (89%) of the patients who contributed bowel diary data at 5 years had at least a 50% improvement from baseline in weekly incontinent episodes, and 26 36%) of the 72 patients had achieved total continence. It is uncertain whether outcomes differed in the 40% of patients missing from the 5-year analysis.
A study by Altomare et. al. (2015) also reported on long-term outcome (minimum, 60-month follow-up; median, 84-month follow-up) in patients implanted with a sacral nerve stimulator for fecal incontinence. Patients were identified from a European registry and surveyed. Long-term success was defined as maintaining the temporary stimulation success criteria, i.e., at least 50% reduction in the number of fecal incontinence episodes (or fecal incontinence symptom score) at last follow-up, compared with baseline. A total of 272 patients underwent permanent implantation of an SNS device, and 228 were available for follow-up. A total of 194 (71.3%) of the 272 patients with implants, maintained improvement in the long-term.
The evidence consists of randomized controlled trials (RCTs), observational studies, systematic reviews of RTCs and uncontrolled studies. Collectively, findings from these studies have suggested that sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM) improve outcomes when used to treat chronic fecal incontinence in well-selected patients who have failed conservative therapy.
The Cochrane review by Thaha et. al. (2015) assessed sacral nerve stimulation (SNS) for constipation and fecal incontinence in adults. Two trials on SNM for constipation were included (Dinning et al , and a crossover trial). In 1 trial, the time with abdominal pain and bloating decreased during the “on” period from 79% to 33%. However, in the larger Dinning trial (discussed below), there was no improvement with SNM during the “on” period. Reviewers concluded: “SNS did not improve symptoms in patients with constipation.”
Thomas et. al. (2013) published a systematic review of controlled and uncontrolled studies evaluating sacral nerve stimulation (SNS) for treatment of chronic constipation. Reviewers identified 11 case series and 2 blinded crossover studies. Sample sizes for the case series ranged from 4 to 68 patients implanted with a permanent SNS device; in 7 of the 11 studies, fewer than 25 patients underwent SNS implantation. Among the 2 crossover studies, one included 2 patients implanted with an SNS device. The other, a study by Knowles et al (2012),21 evaluated temporary stimulation in only 14 patients (see below). Patients were included if they were diagnosed with evacuatory dysfunction and rectal hyposensitivity and had failed maximal conservative treatment. They were randomized to 2 weeks of stimulation with the SNS device turned on and 2 weeks with the SNS device turned off, in random order. There was no wash-out period between treatments. The primary efficacy outcome was change in rectal sensitivity, which was assessed using 3 measures of rectal sensory thresholds. The trial found a statistically significantly greater increase in rectal sensitivity with the device turned on for 2 of the 3 measures. Among the secondary outcome measures, there was a significantly greater benefit of active treatment on the percentage of successful bowel movements per week and the percentage of episodes with a sense of complete evacuation. In addition to its small sample size, the trial lacked a washout period between treatments (ie, there could have been a carryover effect when the device was used first in the on position). Moreover, the patients were highly selected; only 14 of the approximately 1800 patients approached met the eligibility criteria and agreed to participate in the study.
A larger randomized crossover trial was published by Dinning et. al. (2015). The trial included patients (age range, 18-75 years) with slow transit constipation. Potentially eligible patients completed a 3-week stool diary and, in order to continue participating, they had to indicate in the diary that they had complete bowel movements less than 3 days per week for at least 2 of the 3 weeks. Patients with metabolic, neurogenic, or endocrine disorders known to cause constipation were excluded. Fifty-seven met eligibility criteria and had temporary (percutaneous nerve evaluation) PNE, and 55 underwent permanent implantation. In random order, patients received active stimulation (subsensory in phase 1, suprasensory in phase 2) or sham stimulation (device was on, but pulse width and frequency were set to 0). The primary outcome measure, determined by stool diaries, was a bowel movement with feelings of complete evacuation more than 2 days per week for at least 2 of 3 weeks; it was only assessed in phase 2. Compared with sham stimulation, 16 (29.6%) of 54 patients met the primary outcome during suprasensory stimulation, and 11 (20.8%) of 53 patients met it during sham stimulation; the difference was not statistically significant (p=0.23). Other outcomes did not differ significantly with suprastimulation vs sham stimulation and outcomes did not differ in the phase 1 comparison of subsensory vs sham stimulation.
Zerbib et. al. (2017) reported on a double-blind crossover RCT of (sacral nerve stimulation) SNS in 36 women with refractory constipation. Subjects were eligible if they had chronic constipation (>1 year), with 2 or fewer bowel movements per week, straining to evacuate with more than 25% of attempts, or sensation of incomplete evacuation with more than 25% of attempts, with lack of response to standard therapies. Thirty-six subjects meeting inclusion criteria underwent an initial peripheral nerve evaluation (PNE); those who had adequate symptom improvement to a predefined level were offered permanent SNS implant. After a 2-week washout, subjects were randomized to “on” or “off” for 8 weeks, followed by a 2-week washout, when the groups crossed over. Of the 36 patients enrolled, 20 responded and underwent randomization. Four were excluded (2 due to wound infection, 1 each due to the withdrawal of consent and lack of compliance). At 1-year follow-up, a positive response was observed in 12 of 20 and 11 of 20 patients after active and sham stimulation periods, respectively (p=0.746).
One of the larger case series was published by Kamm et al (2010). This prospective study was conducted at multiple sites in Europe. It included 62 patients who had idiopathic chronic constipation lasting at least 1 year and who had failed medical and behavioral treatments. Constipation was defined as at least one of the following: fewer than 2 bowel movements per week, straining to evacuate in at least 25% of attempts, or a sensation of incomplete evacuation on at least 25% of occasions. Forty-five (73%) of the 62 met criteria for permanent implantation during the 3-week trial period. Criteria included an increase in evacuation frequency to at least 3 per week or a 50% reduction in either frequency of straining during evacuation or in episodes with the sensation of incomplete evacuation. After a median follow-up of 28 months (range, 1-55 months) after permanent implantation, 39 (87%) of 45 patients were classified as treatment successes (ie, met the same improvement criteria as used to evaluate temporary stimulation). There was a significant increase in the frequency of bowel movements from a median of 2.3 per week at baseline to 6.6 per week at latest follow-up (p<0.001). The frequency of spontaneous bowel movements (i.e., without laxatives or other stimulation) increased from a median of 1.7 per week at baseline to 4.3 per week at last follow-up (p=0.001). A total of 101 adverse events were reported; 40 (40%) of these were attributed to underlying constipation or an unrelated diagnosis. Eleven serious adverse events related to treatment were reported (the authors did not specify whether any patients experienced >1 serious event). The serious adverse events included a deep postoperative infection (n=2), superficial erosion of lead through the skin (n=1), persistent postoperative pain at the site of implantation (n=2), conditions leading to lead revision (n=4), and device failure (n=2). The study was criticized for including a large number of patients who had more than 2 bowel movements per week at study entry.
Another study, published by Maeda et al (2010), focused on adverse events. This chart review included 38 patients with constipation who received permanent sacral nerve stimulation (SNS) after a successful trial period. When charts were reviewed, a mean of 25.7 months had elapsed since implantation. A total of 58 reportable events were identified in 22 (58%) of the 38 patients. A median of 2 (range, 1-9) events per patient was reported; 26 (45%) of 58 events were reported in the first 6 months after device implantation. The most common reportable events were lack or loss of efficacy (26/58 [45%] events) and pain (16 [28%] events). Twenty-eight (48%) of the events were resolved by reprogramming. Surgical interventions were required for 19 (33%) of the events, most commonly permanent electrode replacement (14 events). Three (8%) of 38 patients discontinued device use due to reportable events.
Four randomized crossover studies are available; two had very small sample sizes, and the others did not find significant differences in outcomes when active sacral nerve stimulation (SNS) was compared with sham stimulation. There are also several, mainly small, case series. Collectively, they represent insufficient evidence to permit scientific conclusions about the effect of sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM) on net health outcomes in patients with constipation.
A systematic review by Tirlapur et. al. (2013), evaluating studies on nerve stimulation for chronic pelvic pain, did not identify any RCTs on sacral nerve stimulation (SNS) for treatment of chronic pelvic pain or bladder pain. The published evidence was limited to case series. For example, Martellucci et. al. (2012) reported on 27 patients with chronic pelvic pain (at least 6 months) who underwent testing for sacral nerve neuromodulation (SNM) implantation. After a 4-week temporary stimulation phase, 16 (59%) of 27 patients underwent implantation of an InterStim device. In the 16 implanted patients, mean pain on a visual analog scale was 8.1 before implantation and 2.1 at the 6- and 12-month follow-ups. An earlier study by Siegel et al (2001) reported on 10 patients and reported that 9 of them experienced a decrease in pain with SNS stimulation.
Data from several small case series with heterogenous patient samples represent insufficient evidence on the effect of sacral nerve neuromodulation (SNM) and sacral nerve stimulation (SNS) on net health outcomes in patients with chronic pelvic pain. Randomized controlled trials (RCTs) are needed, especially with sham controls, reporting pain as the primary outcome.
For individuals with urinary incontinence who have failed conservative treatment who receive sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM), the evidence includes randomized controlled trials (RCTs) and case series with long-term follow-up have suggested that sacral nerve stimulation/neuromodulation (SNS/SNM) reduces symptoms of urge incontinence, urgency-frequency syndrome, non-obstructive urinary retention and overactive bladder in selected patients. The evidence is sufficient to determine that the technology results in a meaningful improvement in net health outcomes.
For individuals with fecal incontinence who have failed conservative treatment who receive sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM), the evidence consists of randomized controlled trials (RCTs), observational studies, systematic reviews of RTCs and uncontrolled studies. Collectively, findings from these studies have suggested that sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM) improve outcomes when used to treat chronic fecal incontinence in well-selected patients who have failed conservative therapy. The evidence is sufficient to determine that the technology results in a meaningful improvement in net health outcomes.
For individuals with constipation who have failed conservative treatment who receive sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM), the evidence includes randomized controlled trials (RCTs) and systematic reviews. The available trials have not consistently reported improvements in outcomes with SNS/SNM. Additional studies are needed to demonstrate the health benefits of this technology. The evidence is insufficient to determine the effects of the technology on net health outcomes.
For individuals with chronic pelvic pain who receive sacral nerve stimulation (SNS)/sacral nerve neuromodulation (SNM), the evidence is limited to case series. The evidence is insufficient to determine the effects of this technology on net health outcomes.
2015 practice parameter, The American Society of Colon and Rectal Surgeons’ Clinical Practice Guideline for the Treatment of Fecal Incontinence states sacral neuromodulation may be considered as first line surgical option for incontinent patients with and without sphincter defects. Grade of Recommendation: Strong recommendation based on moderate quality of evidence, 1B.
In 2014, ACG issued a clinical guideline management of benign anorectal disorders which includes fecal incontinence. Recommendations for surgical treatment include sacral nerve stimulation and states: “sacral nerve stimulation should be considered in patients with fecal incontinence who do not respond to conservative therapy” (strong recommendation, moderate quality of evidence).
In 2007 guidance on management of fecal incontinence recommended: A trial of temporary sacral nerve stimulation should be considered for people with fecal incontinence in whom sphincter surgery is deemed inappropriate. These may be patients with intact anal sphincters, or those with sphincter disruption. In those with a defect, contraindications to direct repair may include atrophy, denervation, a small defect, absence of voluntary contraction, fragmentation of the sphincter or a poor-quality muscle.
All individuals should be informed of the potential benefits and limitations of this procedure and should undergo a trial stimulation period of at least 2 weeks to determine if they are likely to benefit. People with fecal incontinence should be offered sacral nerve stimulation on the basis of their response to percutaneous nerve evaluation during specialist assessment, which is predictive of therapy success. People being considered for sacral nerve stimulation should be assessed and managed at a specialist center that has experience of performing this procedure.
In 2014, the American Urological Association (AUA) and the Scoeity of Urodynamic, Female Pelvic Medicine & Urogenital Reconstruction (SUFU) issued an updated guideline on diagnosis and treatment of overactive bladder. The guideline states that sacral neuromodulation may be offered as a third-line treatment in carefully selected patients with severe refractory symptoms or in those who are not candidates for second line therapy (e.g. oral anti-muscarinics, oral B3 – adrenoceptor agnoists or transdermal oxybutynin) and are willing to undergo surgery.
A 2005 practice bulletin on urinary incontinence considered sacral nerve stimulation to be beneficial for treating chronic voiding dysfunction. An updated practice bulletin in 2015 on urinary incontinence did not address sacral nerve stimulation.
ACOG FAQ on Urinary Incontinence issued February 2016 states: What procedures are available to treat urgency urinary incontinence: Sacral neuromodulation – this is a technique in which a thin wire is placed under the skin of the low back and close to the nerve that controls the bladder. The wire is attached to a battery device placed under the skin nearby. The device sends a mild electrical signal along the wire to improve bladder function.
2004 guidance on the management of urge incontinence and urgency frequency recommended: Sacral nerve stimulation is used to treat the symptoms of an overactive bladder (OAB), including urinary urge incontinence and/or urgency frequency in patients who have failed or cannot tolerate conventional treatments.
In 1997, the Medtronic® InterStim® Therapy System received FDA approval for marketing for the indication of urinary incontinence in patients who have failed or could not tolerate more conservative treatments. In 1999, the device received FDA approval for the additional indications of urgency-frequency and urinary retention in patients without mechanical obstruction. In 2006, the Medtronic InterStim II System received FDA approval for treatment of intractable cases of overactive bladder and urinary retention. The new device is smaller and lighter than the original system and is reported to be suited for those with lower energy requirements or small stature. The device also includes updated software and programming options. In 2011, Medtronic InterStim System received FDA approval for the indication of chronic fecal incontinence in patients who have failed or could not tolerate more conservative treatments. The InterStim device has not been specifically approved by the FDA for treatment of chronic pelvic pain. FDA product code: EZW.
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Replacement or revision of sacral nerve stimulation/sacral nerve neuromodulation may be considered medically necessary for an individual that meets the above criteria and the existing generator/lead/electrodes/programmer is no longer under warranty and cannot be repaired.
Sacral nerve neuromodulation (SNM)/sacral nerve stimulation (SNS) is considered investigational for all other indications, including but not limited to the following, because safety and/or effectiveness cannot be established based on the peer reviewed medical literature:
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