Is sacral nerve stimulation an effective treatment for chronic idiopathic anal pain?

Spinal Cord Stimulation for Intractable Visceral Pain Originating from the Pelvic and Abdominal Region: A Narrative Review on a Possible New Indication for Patients with Therapy-Resistant Pain

Aim

Visceral pain, characterized by pain that is diffuse and challenging to localize, occurs frequently and is difficult to treat. In cases where the pain becomes intractable despite optimal medical management, it can affect patients' Quality of Life (QoL). Spinal Cord Stimulation (SCS) has emerged as a potential solution for intractable visceral pain.

Purpose

In this narrative review, we collected all evidence regarding the efficacy of SCS for visceral pain across various underlying conditions.

Methods

A comprehensive literature search was conducted in PubMed, Embase, and Web of Science in which articles published from October 1st, 1963 up to March 7th, 2023 were identified.

Results

Seventy articles were included in this review of which most were retrospective cohort studies, case series and case reports. The studies, often with a small number of participants, reported on SCS for chronic pancreatitis, anorectal pain and bowel disorders, gynaecological diagnoses, visceral pelvic pain, urological disorders and finally general visceral pain. They found positive effects on pain and/or symptom relief, opioid consumption, anxiety and depression and QoL. Complications occurred frequently but were often minor and reversible.

Conclusion

Better screening and selection criteria need to be established to optimally evaluate eligible patients who might benefit from SCS. A positive outcome of a sympathetic nerve block appears to be a potential indicator of SCS effectiveness. Additionally, women receiving SCS for endometriosis had a better outcome compared to other indications. Finally, SCS could also relief functional symptoms such as voiding problems and gastroparesis. Complications could often be resolved with revision surgery. Since SCS is expensive and not always covered by standard health insurance, the incorporation of cost-analyses is recommended. In order to establish a comprehensive treatment plan, including selection criteria for SCS, rigorous prospective, possibly randomized and controlled studies that are diagnosis-oriented, with substantial follow-up and adequate sample sizes, are needed.

Neuromodulation for the management of chronic pelvic pain syndromes: A systematic review

BACKGROUND

Chronic pelvic pain is a burdensome condition that involves multiple medical sub-specialties and is often difficult to treat. Sacral stimulation for functional bladder disease has been well established, but little large-scale evidence exists regarding utilization of other neuromodulation techniques to treat chronic pelvic pain. Emerging evidence does suggest that neuromodulation is a promising treatment, and we aim to characterize the use and efficacy of such techniques for treating chronic pelvic pain syndromes.

MATERIALS AND METHODS

A systematic review of the literature demonstrating the treatment of chronic pelvic pain syndromes with neuromodulation. Abstracts were reviewed and selected for inclusion, including case series, prospective studies, and randomized controlled trials (RCTs). Case studies and publications in abstract only were not included. The reporting for this systematic review follows Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The literature search was performed using MEDLINE, Embase, Cochrane Library, PubMed, CINAHL, and Scopus.

RESULTS

A total of 50 studies were included in this review, three of which were randomized controlled trials, and the remaining were prospective and retrospective case series. The range of pelvic pain conditions treated included interstitial cystitis, peripheral neuralgia, pudendal neuralgia, gastrointestinal pain, urogenital pain, sacroiliac joint pain, and visceral chronic pelvic pain. We reported on outcomes involving pain, functionality, psychosocial improvement, and medication reduction.

CONCLUSIONS

Neuromodulation is a growing treatment for various chronic pain syndromes. Peripheral nerve stimulation was the least studied form of stimulation. Posterior tibial nerve stimulation appears to offer short-term benefit, but long-term results are challenging. Sacral nerve stimulation is established for use in functional bladder syndromes and appears to offer pain improvement in these patients as well. Dorsal root ganglion stimulation and spinal cord stimulation have been used for a variety of conditions with promising results. Further studies of homogeneous patient populations are necessary before strong recommendations can be made at this time, although pooled analysis may also be impactful.

Pathoetiology of Levator Ani Syndrome and Its Treatment With Translumbosacral Neuromodulation Therapy

INTRODUCTION

The pathoetiology and treatment of levator ani syndrome (LAS) remain unclear.

METHODS

We evaluated pathophysiology using translumbosacral motor-evoked potentials and anorectal manometry in patients with LAS and compared with healthy controls. A cohort underwent translumbosacral neuromodulation therapy (TNT).

RESULTS

Lumbar and sacral motor-evoked potential latencies were prolonged in 32 patients with LAS compared with 31 controls ( P < 0.013), with higher prevalence of anal neuropathy ( P = 0.026). TNT improved anorectal pain ( P = 0.003) and neuropathy ( P < 0.02) in 13 patients with LAS.

DISCUSSION

Patients with LAS demonstrate significant lumbosacral neuropathy that may cause anorectal pain. TNT improved anorectal pain and neuropathy, providing a novel therapeutic option.

Regulation of enteric nervous system via sacral nerve stimulation in opioid-induced constipated rats

Objectives

Sacral nerve stimulation (SNS) has been employed for treating constipation. However, its mechanisms involving enteric nervous system (ENS) and motility are largely unknown. In this study, we investigated the possible ENS involvement of SNS in treating Loperamide-induced constipation in rats.

Methods

Experiment-1 was designed to study the effects of acute SNS on whole colon transit time (CTT). In experiment-2, we induced constipation by Loperamide and then applied daily SNS or sham-SNS for 1 week. Choline acetyltransferase (ChAT), nitric oxide synthase (nNOS), and PGP9.5 in colon tissue were examined at the end of the study. Moreover, survival factors such as phosphorylated AKT (p-AKT) and Glial cell-derived neurotrophic factor (GDNF) were measures by immunohistochemistry (IHC) and western blot (WB).

Key results

(1) SNS with one set of parameters shortened CTT starting at 90 min after phenol red administration (p < 0.05). (2) While Loperamide induced slow transit constipation with a significant reduction in fecal pellet number and feces wet weight, daily SNS for a week resolved constipation. (3) Moreover, SNS was able to shorten whole gut transit time comparing to sham-SNS (p = 0.01). (4) Loperamide reduced the number of PGP9.5 and ChAT positive cells, and downregulated ChAT protein expression and upregulated nNOS protein expression, whereas these detrimental effects were significantly reversed by SNS. (5) Furthermore, SNS increased expressions of both GDNF and p-AKT in colon tissue. (6) Vagal activity was reduced following Loperamide (p < 0.01); yet SNS normalized vagal activity.

Conclusion

SNS with appropriate parameters improves opioid-induced constipation and reversed the detrimental effects of Loperamide on enteric neurons possibly via the GDNF-PI3K/Akt pathway.GRAPHICAL ABSTRACT.

Sacral neuromodulation in the management of chronic pelvic pain: A systematic review and meta-analysis

INTRODUCTION

Sacral neuromodulation (SNM) is a treatment approved for use in several conditions including refractory overactive bladder (OAB) and voiding dysfunction. Chronic pelvic pain (CPP) is a debilitating condition for which treatment is often challenging. SNM shows promising effect in patients with refractory CPP. However, there is a lack of clear evidence, especially in long-term outcomes. This systematic review will assess outcomes of SNM for treating CPP.

METHODS

A systematic search of MEDLINE, Embase, Cochrane Central and clinical trial databases was completed from database inception until January 14, 2022. Studies using original data investigating SNM in an adult population with CPP which recorded pre and posttreatment pain scores were selected. Primary outcome was numerical change in pain score. Secondary outcomes were quality of life assessment and change in medication use and all-time complications of SNM. Risk of bias was assessed using the Newcastle Ottawa Tool for cohort studies.

RESULTS

Twenty-six of 1026 identified articles were selected evaluating 853 patients with CPP. The implantation rate after test-phase success was 64.3%. Significant improvement of pain scores was reported in 13 studies; three studies reported no significant change. WMD in pain scores on a 10-point scale was -4.64 (95% confidence interval [CI] = -5.32 to -3.95, p < 0.00001) across 20 studies which were quantitatively synthesized: effects were maintained at long-term follow-up. Mean follow-up was 42.5 months (0-59). Quality of life was measured by RAND SF-36 and EQ-5D questionnaires and all studies reported improvement in quality of life. One hundred and eighty-nine complications were reported in 1555 patients (Clavien-Dindo Grade I-IIIb). Risk of bias ranged from low to high risk. Studies were case series and bias stemmed from selection bias and loss to follow-up.

CONCLUSION

Sacral Neuromodulation is a reasonably effective treatment of Chronic Pelvic Pain and significantly reduces pain and increases patients' quality of life with immediate to long-term effects.

Neuromodulation for Management of Chronic Pelvic Pain: A Comprehensive Review

INTRODUCTION

Chronic pelvic pain (CPP) is a symptom that derives from a complex group of heterogeneous pathologies of the pelvic organs. The aim of this study was to review the available evidence on efficacy of neuromodulatory modalities including sacral neuromodulation, dorsal root ganglion stimulation, dorsal column neuromodulation, and pudendal nerve stimulation.

METHODS

This narrative review focuses on updated information on neuromodulation for management of chronic pelvic pain. In 2022, we searched English-language studies on neuromodulation, pelvic pain, and chronic pain in a comprehensive search. We searched the following databases: PubMed, Medline, SciHub, Cochrane Database of Systematic Reviews, and Google Scholar. We used the following combinations of keywords: neuromodulation, pelvic pain, chronic pain, chronic pelvic pain, pelvic pain treatment. We tried to include as many recent manuscripts as possible (within the last 3 years) but also included papers older than 3 years if they were particularly relevant to our topic. We also attempted to search for, use, and cite primary manuscripts whenever possible.

RESULTS

CPP is a challenging entity to treat because of diagnostic inconsistencies and limited evidence for therapeutic modalities. Our review found evidence suggestive of benefit for all modalities reviewed but the data was of overall low quality with numerous limitations. The literature highlights a lack of randomized controlled trials for neuromodulatory therapies but suggests a growing role for such techniques in treating refractory chronic pelvic pain syndrome (CPPS).

CONCLUSIONS

This review explores the available evidence on efficacy of neuromodulatory modalities for CPPS and contextualizes the results with information about the type of neuromodulation, lead location and waveform, pain outcomes and assessment timepoints, and reported adverse effects.

Optimal management of functional anorectal pain: a systematic review and network meta-analysis

Functional anorectal is idiopathic and characterised by severe and potentially intractable anorectal pain. The current review aims to appraise available evidence for the management of functional anorectal pain and synthesise reported outcomes using network meta-analysis. PubMed, CENTRAL and Web of Science databases were searched for studies investigating treatments for functional anorectal pain. The primary outcome was clinical improvement of symptoms and the secondary outcome was pain scores reported during follow-up. A Bayesian network meta-analysis of interventions was performed. A total of 1538 patients were included from 27 studies. Intramuscular injection of triamcinolone, sacral neuromodulation (SNM) and biofeedback were most likely to be associated with improvement in symptoms [SUCRA (triamcinolone) = 0.79; SUCRA (SNM) = 0.74; SUCRA (Biofeedback) = 0.61]. Electrogalvanic stimulation (EGS), injection of botulinum toxin A and topical glyceryl trinitrate (GTN) were less likely to produce clinical improvement [SUCRA (EGS) = 0.53; SUCRA (Botox) = 0.30; SUCRA (GTN) = 0.27]. SNM and biofeedback were associated with the largest reductions in pain scores [mean difference, range (SNM) = 4.6-8.2; (Biofeedback) = 4.6-6]. As biofeedback is noninvasive and may address underlying pathophysiology, it is a reasonable first-line choice in patients with high resting pressures or defecation symptoms. In patients with normal resting pressures, SNM or EGS are additional options. Although SNM is more likely to produce a meaningful response compared to EGS, EGS is noninvasive and has less morbidity. Whilst triamcinolone injection is associated with symptomatic clinical improvement, the magnitude of pain reduction is less.

Neuro-Immune Modulation Effects of Sacral Nerve Stimulation for Visceral Hypersensitivity in Rats

Background: Visceral hypersensitivity (VH) is one of the underlying pathophysiologies of irritable bowel syndrome. Mast cell overactivation has been found to be one of the main causes of VH. We investigated the effects and mechanisms of actions of sacral nerve stimulation (SNS) on visceral pain in a rodent model of VH.

Methods: The VH was established by an intrarectal infusion of AA in 10-day-old pups. Rats were chronically implanted with electrodes for SNS and recording electromyogram (EMG) and electrocardiogram. The acute study was performed in 2-randomized sessions with SNS (14 Hz, 330 μs, 40% motor threshold or MT, 30 min) or sham-SNS. Later on, rats were randomized into SNS/sham-SNS groups and a chronic study was performed with 2 h-daily SNS or sham-SNS for 21 days. Visceromotor reflexes were assessed by abdominal EMG and withdrawal reflex (AWR). Colon tissues were collected to study colonic acetylcholine (ACh), the enteric neurons (ChAT, nNOS, and PGP9.5), mast cells activity [Tryptase, prostaglandins E2 (PGE2), and cyclooxygenases-2 (COX2)] and pain markers [nerve growth factor (NGF) and Sub-P].

Key Results: Sacral nerve stimulation significantly improved visceromotor reflexes assessed by the EMG and AWR, compared with sham-SNS. SNS normalized the protein expressions of ChAT and nNOS and regulated mast cells activity by downregulating Tryptase, COX2, and PGE2. Neonatal AA administration upregulated NGF and Sub-P; chronic SNS significantly decreased these pain biomarkers. Concurrently, chronic SNS increased ACh in colon tissues and vagal efferent activity.

Conclusions: Sacral nerve stimulation reduces VH in rats and this ameliorating effect might be attributed to the suppression of mast cell overactivation in the colon tissue via the modulation of autonomic nervous system functions.

Proctalgia Syndromes: Update in Diagnosis and Management

PURPOSE OF REVIEW

Functional anorectal pain syndromes are a neglected yet often disabling clinical entity resulting in significant economic and psychological burden to the patient. The aim of this review is to update the practicing gastroenterologist/coloproctologist on the diagnosis and management of these complicated disorders.

RECENT FINDINGS

The updated Rome foundation diagnostic criteria (Rome IV) for functional anorectal pain subgroups chronic proctalgia (levator ani syndrome and unspecified functional anorectal pain) and acute proctalgia (proctalgia fugax) on the basis of symptom duration and digital rectal examination findings. Chronic proctalgia is thought to be secondary to paradoxical pelvic floor contraction in many patients and biofeedback to improve the defecation effort has proven effective for over 90% in the short term. Unfortunately, management of proctalgia fugax remains challenging and treatment outcomes modest at best. A number of therapies to relax the pelvic floor may be employed to improve symptoms in functional anorectal pain syndromes; however, only biofeedback to improve defaecatory dynamics in patients with levator ani syndrome has proven effectiveness in a randomized setting. Further investigation of treatment approaches in proctalgia fugax is required.

Sacral nerve stimulation with optimized parameters improves visceral hypersensitivity in rats mediated via the autonomic pathway

The purpose of this study was to determine effects and mechanisms of sacral nerve stimulation (SNS) on visceral hypersensitivity in rodent models of colonic hypersensitivity. SNS was performed with different sets of parameters for 30 min in six regular rats. Visceral sensitivity was assessed by the measurement of electromyogram and abdominal withdrawal reflex before and after SNS. Real/sham SNS with optimized parameters was performed in 8 restraint stress-induced visceral hypersensitivity rats and 10 neonatal acetic acid-treated colonic hypersensitivity rats; acute effect of SNS was assessed by comparing electromyogram and heart rate variability. Neonatal acetic acid-treated rats were treated by SNS (n = 10) or sham-SNS (n = 10) daily for seven days for the assessment of the chronic effect of SNS. (1) When the stimulation amplitude was reduced from 90% of motor threshold to 65% or 40% motor threshold, SNS with certain parameters showed an inhibitory effect on abdominal withdrawal reflex. The best stimulation parameters for SNS were “14 Hz, 330 µs, and 40% motor threshold.” (2) SNS significantly reduced visceral hypersensitivity and improved autonomic function in restraint stress-induced rats. The inhibitory effect was blocked by naloxone. (3)Acute and chronic SNS significantly reduced visceral hypersensitivity and improved autonomic function in acetic acid-treated rats. SNS with reduced stimulation strength may be used to treat colonic hypersensitivity and the best stimulation parameters seem to be “14 Hz, 330 µs and 40% motor threshold”. SNS with optimized parameters improved visceral hypersensitivity in rodent models of colonic hypersensitivity mediated via the autonomic and opioid mechanisms.

Anti-inflammatory effects of sacral nerve stimulation: a novel spinal afferent and vagal efferent pathway

Sacral nerve stimulation (SNS) was reported to improve 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. The aim of this study was to investigate whether the SNS anti-inflammatory effect is mediated via the local sacral splanchnic nerve or the spinal afferent-vagal efferent-colon pathway. Under general anesthesia, rats were administrated with TNBS intrarectally, and bipolar SNS electrodes were implanted unilaterally at S₃. The sacral and vagal nerves were severed at different locations for the assessment of the neural pathway. SNS for 10 days improved colonic inflammation only in groups with intact afferent sacral nerve and vagus efferent nerve. SNS markedly increased acetylcholine and anti-inflammatory cytokines (IL-10) and decreased myeloperoxidase and proinflammatory cytokines (IL-2, IL-17A, and TNF-α) in colon tissues. SNS increased the number of c-fos-positive cells in the brain stem and normalized vagal activity measured by spectral analysis of heart rate variability. SNS exerts an anti-inflammatory effect on TNBS-induced colitis by enhancing vagal activity mediated mainly via the spinal afferent-brain stem-vagal efferent-colon pathway.NEW & NOTEWORTHY Our findings support that there is a possible sacral afferent-vagal efferent pathway that can transmit sacral nerve stimulation to the colon tissue. Sacral nerve stimulation can be carried out by spinal cord afferent to the brain stem and then by the vagal nerve (efferent) to the target organ.

Outcomes of sacral neuromodulation for chronic pelvic pain: a Finnish national multicenter study

BACKGROUND

The aim of this study was to report the outcomes of sacral neuromodulation (SNM) in chronic pelvic pain (CPP) patients in the Finnish national cohort.

METHODS

This was a register-based retrospective study, involving all the centers that provide SNM treatment in Finland. The data of all patients treated with SNM for CPP were gathered from Oulu-, Turku-, Tampere- and Helsinki University Hospitals, as well as Jyväskylä and Seinäjoki Central Hospitals. All patients who had been tested for SNM implantation prior to April 2017 were included in the study.

RESULTS

A total of 51 patients were selected for SNM treatment due to CPP from 2004 until 2017. The mean follow-up time was 13.8 months (SD 22.9 months). A total of 28 patients (57%) advanced from testing to permanent stimulator implantation. There were 21 patients (41%) who had a working modulator implanted at the end of follow-up. Patients with endometriosis-related pain had a significantly higher permanent implantation rate than the overall implantation rate (88% vs. 57%; p = 0.01). The endometriosis patients also had a higher overall success rate by the end of the follow-up (75% vs. 41%; p = 0.026) CONCLUSIONS: SNM may be a viable treatment option for patients with CPP due to endometriosis. Further research on SNM treatment for endometriosis patients with refractory CPP is needed.

Sacral nerve stimulation improves colonic inflammation mediated by autonomic-inflammatory cytokine mechanism in rats

BACKGROUND

Vagal nerve stimulation (VNS) was reported to have a therapeutic potential for inflammatory bowel disease (IBD). This study was designed to determine effects and mechanisms of SNS on colonic inflammation of in rodent models of IBD and compare the difference among SNS, VNS, and SNS plus VNS.

METHODS

Intestinal inflammation in rats was induced by intrarectal administration of TNBS (2,4,6-Trinitrobenzenesulfonic acid) on the first day. Five days after intrarectal TNBS, the rats were treated with sham-VNS, VNS, Sham-SNS, SNS, and SNS + VNS for 10 days. In another experiment, after 10 days of 4% DSS (dextran sodium sulfate) in drinking water, rats were treated with 10-day sham-SNS and SNS. Various inflammatory responses were assessed; mechanisms involving autonomic functions and inflammatory cytokines were investigated.

KEY RESULTS

(a) VNS, SNS, and VNS + SNS significantly and equally decreased the disease activity index and macroscopic scores, and normalized colon length; (b) IL-10 was decreased by TNBS but increased with SNS, VNS, and SNS + VNS; pro-inflammatory cytokines, IL-6, IL-17A, MCP-1 and TNF-α, were increased by TNBS but decreased with SNS, VNS, and SNS + VNS (P < .05); MPO activity was decreased by SNS, VNS, and SNS + VNS; (c) SNS, VNS, and SNS + VNS remarkably increased vagal activity that was suppressed by TNBS (P < .05); (d) smilar SNS effects were noted in rats with DSS-induced colitis.

CONCLUSIONS & INFERENCES

SNS presents similar anti-inflammatory effects as VNS by inhibiting pro-inflammatory cytokines and increasing anti-inflammatory cytokines via the autonomic pathway. Similar to VNS, SNS may also have a therapeutic potential for colonic inflammation.

Sacral neuromodulation treating chronic pelvic pain: a meta-analysis and systematic review of the literature

INTRODUCTION AND HYPOTHESIS

Sacral neuromodulation (SNM) is gaining popularity as a treatment option for chronic pelvic pain (CPP). Our hypothesis is that SNM is effective in improving CPP.

METHODS

A systematic search was conducted through September 2018. Peer-reviewed studies using pre- and postpain intensity scores were selected. The primary outcome was pain improvement on a 10-point visual analog scale (VAS) (adjusted or de novo) in patients with CPP. Secondary outcomes included comparing SNM approaches and etiologies and evaluating lower urinary tract symptoms (LUTS).

RESULTS

Fourteen of 2175 studies, evaluating 210 patients, were eligible for further analysis. The overall VAS pain score improvement was significant [weighted mean difference (WMD) -4.34, 95% confidence interval (CI) = -5.22, to-3.64, p < 0.0001)]. Regarding SNM approach, both standard and caudal approaches had significant reduction in pain scores: WMD -4.32, CI 95% = -5.32, to -3.31 (p < 0.001) for the standard approach, compared with WMD -4.63, 95% CI = -6.57 to -2.69 (P < 0.001), for the caudal approach (p = 0.75). While significant improvement in pain was observed both in patients with and without interstitial cystitis/bladder pain syndrome (IC/BPS), the observed improvement was lower in patients with (WMD -4.13, CI 95% -5.36 to -2.90 versus without (WMD -5.72, CI 95% = -6.18, to-5.27) IC/BPS (p = 0.02). SNM was effective in treating voiding symptoms (frequency, urgency, nocturia) associated with IC/BPS (all p < 0.01).

CONCLUSIONS

SNM is an effective therapy for CPP in both IC/BSP and non-IC/BSP patients, with better results in non-IC/BSP patients. Outcomes of the antegrade caudal approach were comparable with the standard retrograde approach.

Treatment Outcome of Acute Sacral Nerve Stimulation in Functional Anorectal Pain

BACKGROUND

Sacral nerve stimulation (SNS) has revolutionized the management of certain intractable cases of fecal and urinary incontinence; however, the management of functional anorectal pain (FAP) has been addressed in only a few studies.

OBJECTIVE

The aim of this study was to evaluate the treatment effect of SNS in improving FAP symptoms.

METHODS

A total of 120 patients with FAP who had undergone temporary SNS probe placement were investigated at Qianfoshan Hospital between January 2014 and December 2016. Pre- and post-SNS treatment outcomes were assessed using the VAS, anorectal manometry, and the 36-item short-form health survey (SF-36) medical outcomes study instrument.

RESULTS

A total of 120 patients proceeded to insertion of an SNS probe at the S3 nerve root (2 Hz, 1.50 mA, 0.10 milliseconds). Of these, 75 patients were cured, 41 improved, and 4 had an ineffective outcome. The total effectiveness rate was 96.7% 1 year after treatment. There was a significant reduction in the median VAS score pre-SNS and post-SNS, from 8 to 3, respectively. Patients post-SNS had lower anal maximum contraction pressure and anal rest pressure than did patients pre-SNS. Compared with the pretreatment group, there were no substantial differences between anal longest contraction time and rectal rest pressure. In addition to general health, there was a substantial improvement in the remaining dimension scores of the SF-36.

CONCLUSION

The effect of SNS in treating FAP was positive, and the improvement of symptoms was substantial and worthy of clinical promotion.

Increase of n-NOS and i-NOS in Rat Colon After Sacral Neuromodulation

OBJECTIVE

Sacral neuromodulation (SNM) is proposed to treat different anorectal dysfunctions but its mechanism of action is not yet known. Our previous study demonstrated how SNM can significantly increase neuronal nitric oxide synthase NOS (n-NOS) and inducible NOS (i-NOS) expression in the anus and rectum of rats. There are no reports regarding the relation between SNM and NOS in colonic cells: our aim was to assess NOS expression in colonic rat model after SNM.

MATERIALS AND METHODS

Twenty-six female Sprangue-Dawley rats were considered: group I, normal control rats; group II, sham treatment rats, in whom electrodes for electrical stimulation were placed in S1 foramen bilaterally and left in place, without performing neuromodulation; group III, rats in whom SNM was performed. After 14 days, the rats were sacrificed and we evaluated n-NOS and i-NOS in colonic specimens by immunohistochemistry and Western Blot analysis.

RESULTS

Western Blot analysis showed that levels of n-NOS and i-NOS were higher in colon of the III group rats respect to the others; in particular, immunohistochemistry revealed that, after neuromodulation, n-NOS expression in the muscle cells and i-NOS expression in glandular epithelium and nervous cells were highly represented (p < 0.05).

CONCLUSION

Our study showed that in colon, SNM is able to influence NO synthesis, activating n-NOS expression in muscle cells and i-NOS expression in glandular epithelium and nervous cells. Our study showed a complex colonic response to SNM. This experimental model could be applied to better understand the mechanism of action of SNM in bowel dysfunction.

The Clinical Characteristics of Patients with Chronic Idiopathic Anal Pain

The aim of this study was to investigate the clinical characteristics, treatment outcomes and psychological distress in patients with chronic idiopathic anal pain. The study was conducted on patients referred to Hangzhou Third Hospital for chronic anal pain from January, 2010 to December, 2014. Patient demographics, clinical history, anorectal physiology, and radiological imaging data were recorded for all patients. The treatment outcome was noted for patients treated and followed up for more than 6 month at the present unit. Ninety-six patients with mean age of 45.1 years (range, 17-82) were studied. Seventy-one patients (74.0%) had functional anorectal pain(FARP). The main complaints were dull, sharp, stabbing, or spasm pain. Among all patients, 34.3% reported that their pain radiated into other locations. Fifty-one patients (53.1%) had bowel dysfunction, while 28.1% patients had urinary dysfunction. The common factors associated with pain relief were day time, lying down and warm water baths; the factors that contributed to aggravated pain were night time, defecation or sitting. 92.7% (89/96) of patients reported symptoms of psychological disturbance. FARP patients exhibited increased depression than non-FARP patients(P<0.05). In addition, female patients were more likely to have depression than male patients (P<0.05). The overall pain treatment success rate was 55.2% (53/96). The pain treatment outcome was better in non-FARP patients than in FARP patients(χ2=3.85, P<0.05). Conclusively, chronic idiopathic anal pain is a complex clinical symptom, involving pelvic floor muscles, the nervous system, endocrine system, and the patients' psychological conditions. Further research is needed to improve diagnosis and treatment for patients with chronic idiopathic anal pain.

Presacral abscess as a rare complication of sacral nerve stimulator implantation

A 50-year-old man with intractable anal pain attributed to proctalgia fugax underwent insertion of a sacral nerve stimulator via the right S3 vertebral foramen for pain control with good symptomatic relief. Thirteen months later, he presented with signs of sepsis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large presacral abscess. MRI demonstrated increased enhancement along the pathway of the stimulator electrode, indicating that the abscess was caused by infection introduced at the time of sacral nerve stimulator placement. The patient was treated with broad spectrum antibiotics, and the sacral nerve stimulator and electrode were removed. Attempts were made to drain the abscess transrectally using minimally invasive techniques but these were unsuccessful and CT guided transperineal drainage was then performed. Despite this, the presacral abscess progressed, developing enlarging gas locules and extending to the pelvic brim to involve the aortic bifurcation, causing hydronephrosis and radiological signs of impending sacral osteomyelitis. MRI showed communication between the rectum and abscess resulting from transrectal drainage. In view of the progressive presacral sepsis, a laparotomy was performed with drainage of the abscess, closure of the upper rectum and formation of a defunctioning end sigmoid colostomy. Following this, the presacral infection resolved. Presacral abscess formation secondary to an infected sacral nerve stimulator electrode has not been reported previously. Our experience suggests that in a similar situation, the optimal management is to perform laparotomy with drainage of the presacral abscess together with simultaneous removal of the sacral nerve stimulator and electrode.

Anorectal and Pelvic Pain

Although pelvic pain is a symptom of several structural anorectal and pelvic disorders (eg, anal fissure, endometriosis, and pelvic inflammatory disease), this comprehensive review will focus on the 3 most common nonstructural, or functional, disorders associated with pelvic pain: functional anorectal pain (ie, levator ani syndrome, unspecified anorectal pain, and proctalgia fugax), interstitial cystitis/bladder pain syndrome, and chronic prostatitis/chronic pelvic pain syndrome. The first 2 conditions occur in both sexes, while the latter occurs only in men. They are defined by symptoms, supplemented with levator tenderness (levator ani syndrome) and bladder mucosal inflammation (interstitial cystitis). Although distinct, these conditions share several similarities, including associations with dysfunctional voiding or defecation, comorbid conditions (eg, fibromyalgia, depression), impaired quality of life, and increased health care utilization. Several factors, including pelvic floor muscle tension, peripheral inflammation, peripheral and central sensitization, and psychosocial factors, have been implicated in the pathogenesis. The management is tailored to symptoms, is partly supported by clinical trials, and includes multidisciplinary approaches such as lifestyle modifications and pharmacological, behavioral, and physical therapy. Opioids should be avoided, and surgical treatment has a limited role, primarily in refractory interstitial cystitis.

Sacral nerve stimulation for faecal incontinence and constipation: a European consensus statement

AIM

In Europe during the last decade sacral nerve stimulation (SNS) or sacral neuromodulation (SNM) has been used to treat faecal incontinence (FI) and constipation. Despite this, there is little consensus on baseline investigations, patient selection and operative technique. A modified Delphi process was conducted to seek consensus on the current practice of SNS/SNM for FI and constipation.

METHOD

A systematic literature search of SNS for FI and constipation was conducted using PubMed. A set of questions derived from the search and expert opinion were answered on-line on two occasions by an international panel of specialists from Europe. A 1-day face-to-face meeting of the experts finalized the discussion.

RESULTS

Three hundred and ninety-three articles were identified from the literature search, of which 147 fulfilled the inclusion criteria. Twenty-two specialists in FI and constipation from Europe participated. Agreement was achieved on 43 (86%) of 50 domains including the set-up of service, patient selection, baseline investigations, operative technique and programming of the device. The median of agreement was 95% (35-100%).

CONCLUSION

Consensus was achieved on the majority of domains of SNS/SNM for FI and constipation. This should serve as a benchmark for safe and quality practice of SNS/SNM in Europe.

Effects of 1-week sacral nerve stimulation on the rectal intestinal epithelial barrier and neuromuscular transmission in a porcine model

BACKGROUND

Sacral nerve stimulation (SNS) is a validated treatment for fecal incontinence, although the mechanism of action remains unknown. Short-term effects of SNS on the intestinal epithelial barrier (IEB) have been reported previously. The aim of our study was to assess the impact of a 1-week SNS on the IEB in a preclinical model.

METHODS

Fourteen pigs were implanted for bilateral SNS. Seven pigs received 7-day stimulation, whereas the remaining animals received no stimulation. Rectal biopsies were performed before and after SNS. We assessed IEB permeability, mucosal tight junction and cytokine mRNA expression, IL-6 production in an organotypic culture model, and neuromuscular transmission in muscle strips.

KEY RESULTS

IEB permeability was not modified after stimulation, as compared with baseline. The PAR-induced increase in IEB permeability and the mucosal ZO-1 mRNA decrease observed in the controls were not observed into the stimulated group. Cytokine overexpression was not observed in the mucosa in either group. SNS decreased IL-6 production in the organotypic culture model. In the stimulated group, the area-under-the-curve of the EFS-induced contractile response was significantly increased.

CONCLUSIONS & INFERENCES

The main conclusions of our work are (i) the successful development of a preclinical model of bilateral SNS and (ii) in physiological conditions, 1-week SNS did not lead to functional changes in the mucosa. While under stress-induced conditions, SNS modified the properties of the IEB, leading to a decrease in its permeability. Neuromuscular transmission was modified by SNS, leading to neuronal hyperexcitability. These results add evidence to the reinforcement of the IEB by SNS.

A systematic review of sacral nerve stimulation mechanisms in the treatment of fecal incontinence and constipation

BACKGROUND

Sacral nerve stimulation (SNS) is now well established as a treatment for fecal incontinence (FI) resistant to conservative measures and may also have utility in the management of chronic constipation; however, mechanism of action is not fully understood. End organ effects of SNS have been studied in both clinical and experimental settings, but interpretation is difficult due to the multitude of techniques used and heterogeneity of reported findings. The aim of this study was to systematically review available evidence on the mechanisms of SNS in the treatment of FI and constipation.

METHODS

Two systematic reviews of the literature (performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses framework) were performed to identify manuscripts pertaining to (a) clinical and (b) physiological effects of SNS during the management of hindgut dysfunction.

KEY RESULTS

The clinical literature search revealed 161 articles, of which 53 were deemed suitable for analysis. The experimental literature search revealed 43 articles, of which nine were deemed suitable for analysis. These studies reported results of investigative techniques examining changes in cortical, gastrointestinal, colonic, rectal, and anal function.

CONCLUSIONS & INFERENCES

The initial hypothesis that the mechanism of SNS was primarily peripheral motor neurostimulation is not supported by the majority of recent studies. Due to the large body of evidence demonstrating effects outside of the anorectum, it appears likely that the influence of SNS on anorectal function occurs at a pelvic afferent or central level.

Chronic idiopathic anal pain. Results of a diagnostic-therapeutic protocol in a colorectal referral unit

INTRODUCTION

Chronic idiopathic anal pain (CIAP) remains a diagnosis of exclusion. Its study and management still lack a standardized protocol. The aim of this study is to evaluate the results obtained with the diagnostic-therapeutic protocol established in our service.

MATERIAL AND METHODS

We performed a retrospective study of patients diagnosed with CIAP at the Colorectal Unit of the General University Hospital of Elche, between 2005 and 2011.

RESULTS

We evaluated 57 patients with a diagnosis of chronic anal pain for functional anorectal disease (FAD). After the application of our diagnostic protocol, final diagnosis of chronic anal pain (CAP) was achieved in 43 cases (75%), including 22 cases of descending perineum syndrome, 12 of proctalgia fugax, 2 of pudendal neuritis and 7 of coccydynia. In 14 patients exclusion diagnosis of CIAP was established. Among the therapies used on patients with CIAP, biofeedback combined with conservative measures improved symptoms in 43% of the cases. Sacral nerve stimulation was assessed in patients who did not respond to other treatments.

CONCLUSION

Through proper anamnesis, physical examination and complementary tests, a specific diagnosis of the cause of CAP by FAD can be achieved, reducing exclusion diagnosis of CIAP to 25% of cases. Conservative measures combined with biofeedback achieved an improvement in pain in more than 40% of the cases of CIAP in our study. Sacral nerve stimulation can be considered as a treatment option in refractory cases.

Chronic pelvic pain

Chronic pelvic pain is pain lasting longer than 6 months and is estimated to occur in 15% of women. Causes of pelvic pain include disorders of gynecologic, urologic, gastroenterologic, and musculoskeletal systems. The multidisciplinary nature of chronic pelvic pain may complicate diagnosis and treatment. Treatments vary by cause but may include medicinal, neuroablative, and surgical treatments.

Sacral neuromodulation for bowel dysfunction: a consensus statement from the Italian group

BACKGROUND

Representatives from the Italian centers experienced in sacral neuromodulation (SNM) for the treatment of bowel dysfunction met in order to define the current clinical practice in Italy and to produce a consensus statement regarding indications for this therapy and patient management.

METHODS

Fifty Italian colonproctologists were asked to complete a questionnaire concerning their clinical practice in SNM (290 questions, grouped within 4 broad areas). Physicians expressed their opinion by completing the questionnaire, assigning to each statement their level of agreement according to the 5-point Likert scale; the data were analyzed by attributing to each expert's answers a weight proportional to the degree of experience. During a meeting held 2 months later, the critical aspects of the therapy were re-examined and discussions held with the goal of reaching an agreement on controversial topics. The available literature was reviewed.

RESULTS

Patient selection criteria, etiology, diagnostic investigations, test procedures and implantation, follow-up and evaluation of results have been reviewed. The aim was to achieve an algorithm for patient management, showing the place of SNM in the treatment of bowel dysfunction. The approach in case of treatment failure was also discussed.

CONCLUSIONS

Analysis of the data collected reveals substantial consensus at the national level concerning all the main points with regard to the therapy. The recommendations expressed in this article can be considered as national guidelines and taken into account by the principal international implantation centers.

Sacral nerve modulation in the treatment of chronic pelvic pain

BACKGROUND

Chronic pelvic pain is a common condition that significantly compromises the quality of life of affected patients. Unfortunately, despite treatment procedures, the results are often ineffective and symptoms persist for years. For these reasons, the search for less aggressive treatment options with fewer negative consequences leading to minimally invasive techniques was conducted.

OBJECTIVE

The aim of the present study was to evaluate the efficacy of sacral nerve modulation in the treatment of chronic pelvic pain. Moreover, we aimed to identify potential predictors of positive results of sacral neuromodulation through the comparison between failed and successful patients.

PATIENTS

From January 2004 to December 2009, all consecutive patients suffering from chronic pelvic pain and tested for sacral nerve modulation in three pelvic floor dedicated centers were evaluated. Severity of symptoms were analyzed by a visual analog scale (VAS) RESULTS: Twenty-seven patients (2 males; mean age, 53 years) were tested for sacral nerve modulation in the screening period and were included in the present study. The mean duration of pain was 51 months (range, 10-132 months). The mean preoperative VAS was 7.8 (range, 5-10). Previous pelvic surgery was reported in 18 patients (66.5%). Sixteen patients (59%) fulfil the successful criteria and were definitively implanted. The mean follow-up was 37 months (range, 12-71 months). The mean preoperative VAS was 8.1 (range, 6-8) and decreased to 2.1 ± 1.2 at 6-month follow-up (p < 0.0001), to 2.1 ± 1.1 at 12 months (16 patients), to 2.0 ± 1.2 at 24 months (13 patients), to 2.3 ± 1.4 at 36 months (9 patients), to 2.1 ± 1.5 at 48 months (5 patients), and to 1.9 ± 1.3 at 60 months (3 patients).

CONCLUSIONS

Sacral neuromodulation proved to be effective in the treatment of some patients affected by chronic pelvic pain, and the effect persists over time. A positive screening phase and a positive response to gabapentin or pregabalin showed to be predictors of a successful response. Multiple localizations of pelvic pain and pain occurred after stapler surgery seem to be negative factors for the success of the treatment.

Motor cortex stimulation in refractory pelvic and perineal pain: report of two successful cases

AIMS

In some patients, with refractory chronic pelvic and perineal pain, pain and quality of life are barely alleviated despite optimal medical treatment, infiltrations and surgical release of the pudendal nerve. The management of these patients is complex, especially after failure of neuromodulation techniques (spinal cord stimulation. S3 nerve root stimulation and direct stimulation of the pudendal nerve). We report the first two cases illustrating the value of motor cortex stimulation (MCS), in this new indication.

METHODS

The history, decision-making process, intraoperative findings and results of this technique are presented. The perineal cortical area was identified by intraoperative motor evoked potentials in the external anal sphincter, confirming its location in the primary motor cortex between the inferior and superior limb positions. As predictive value of repetitive transcranial magnetic stimulation (rTMS) in the identification of responders to MCS for pain is now established, we performed pre-operative rTMS sessions for both patients.

RESULTS

The first patient was a 74-years-old woman who reported an 11-year history of left lateral perineal pain. The second patient was a 45-year-old woman who reported a 4-year history of perineal pain following hysterectomy with ovariectomy. After respectively 40 months and 19 months of follow up, both patients reported an improvement of pain ranging from 40 to 50%. Time to onset of pain on sitting was markedly improved from a few minutes to 90 minutes, and largely contributing to improvement of activities of daily living and of quality of life.

CONCLUSION

These two first cases suggest that motor cortex stimulation constitutes a new treatment for refractory pelvic and perineal pain, and should be considered after failure of conventional neuromodulation techniques, especially spinal cord stimulation.

Sacral nerve modulation in the treatment of chronic pain after pelvic surgery

AIM

The aim of the study was to evaluate the efficacy of sacral nerve modulation for chronic pelvic pain after pelvic or anal surgery for benign disease.

METHOD

From January 2004 to December 2009, 17 (14 female; age 56 years) consecutive patients suffering from chronic pelvic pain underwent evaluation for sacral nerve modulation in three pelvic floor units.

RESULTS

The previous surgery included stapled transanal rectal resection (five), hysterectomy (four), haemorrhoidectomy (two), stapled haemorrhoidopexy (one), fistulectomy (one), urethral sphincterotomy (one), appendicectomy (one), discectomy (one) and laparoscopy for endometriosis (one). Eight (47%) patients fulfilled the criteria for definitive implantation and were followed for a mean of 39 months. Using a visual analog pain score, pain levels fell from 8.2 preoperatively to 1.9, 2.1, 2.0 and 1.8 at 6, 12, 24 and 36 months, respectively. Age < 60 years and duration of symptoms of < 24 months were good predictors and stapling was a poor predictor of success.

CONCLUSION

Sacral nerve modulation seems to be effective over time in some patients with chronic pain related to previous surgery.

Chronic proctalgia and chronic pelvic pain syndromes: New etiologic insights and treatment options

This systematic review addresses the pathophysiology, diagnostic evaluation, and treatment of several chronic pain syndromes affecting the pelvic organs: chronic proctalgia, coccygodynia, pudendal neuralgia, and chronic pelvic pain. Chronic or recurrent pain in the anal canal, rectum, or other pelvic organs occurs in 7% to 24% of the population and is associated with impaired quality of life and high health care costs. However, these pain syndromes are poorly understood, with little research evidence available to guide their diagnosis and treatment. This situation appears to be changing: A recently published large randomized, controlled trial by our group comparing biofeedback, electrogalvanic stimulation, and massage for the treatment of chronic proctalgia has shown success rates of 85% for biofeedback when patients are selected based on physical examination evidence of tenderness in response to traction on the levator ani muscle-a physical sign suggestive of striated muscle tension. Excessive tension (spasm) in the striated muscles of the pelvic floor appears to be common to most of the pelvic pain syndromes. This suggests the possibility that similar approaches to diagnostic assessment and treatment may improve outcomes in other pelvic pain disorders.

Long-term outcome of the use of botulinum toxin injection for functional anal pain

AIM

Anal pain may occur in the absence of demonstrable anal pathology. Spasm of the sphincter muscles has been suggested as a cause in some patients. We aimed to assess the effectiveness of injection of botulinum toxin in treating this condition.

METHOD

Patients who had injection of botulinum toxin over a 3-year period were identified retrospectively. Patients were excluded if anal fissure or other organic pathology was found to account for their symptoms on examination under anaesthetic. Long-term outcome was assessed at a minimum 3-year post-procedure telephone follow up.

RESULTS

Fourteen (eight male) patients were identified, of median age 50 years. Botulinum toxin (20-200 u) was injected into the internal sphincter. Seven of the 14 patients reported significant improvement in symptoms at 3 months. Seven were available for a structured telephone review at a median of 59 (42-68) months. The four patients who had benefited from the injection had remained asymptomatic.

CONCLUSION

Injection of botulinum toxin into the internal anal sphincter has a role in alleviating symptoms in a small proportion of patients with functional anal pain.

Efficacy of sacral neuromodulation in treatment of bladder pain syndrome: long-term follow-up

AIMS

This study was sought to evaluate the efficacy and durability of sacral neuromodulation in the treatment of bladder pain syndrome (BPS) patients.

METHODS

A retrospective chart review was performed of patients who had unilateral sacral nerve stimulator (InterStim®) for refractory BPS between June 2002 and December 2004. Patients were qualified for permanent implantation by showing ≥ 50% improvement in their bladder pain and voiding symptoms 1-week post-percutaneous nerve evaluation (PNE). Voiding diary was completed at pre-implantation, 1 year, and on the last visit. Urinary distress inventory short form was completed pre-implantation and on the last visit. Bladder pain was evaluated by visual analogue scale. Primary outcome was improvement in bladder pain. Differences among groups were compared by one-way ANOVA and t-test. Statistical significance was set at P ≤ 0.05.

RESULTS

Twenty-one female patients diagnosed with BPS had PNE; 11 patients (52%) showed ≥ 50% improvement in their bladder pain and voiding symptoms and they consider candidates for permanent implantation (Table I), while 10 patients (48%) failed to show 50% improvement in their voiding symptoms or bladder pain (Table II). In those 11 patients who underwent permanent implantation, the average patient's age was 44.3 ± 8.9 years; average time since diagnosis was 3 ± 0.8 years; the average follow- up was 71.5 ± 9.3 months (Table III). There was significant improvement in the bladder pain and voiding parameters at 1-year follow-up, which was maintained at 5-year follow-up. There was continuous improvement in urgency (1.2 ± 0.68) at 1-year follow-up, and (0.98 ± 0.72) at the last visit. Average voided volume was also continuously improved from 242 ± 62.7 ml at 1-year follow-up to 276 ± 64.7 ml on the last visit.

CONCLUSION

Sacral neuromodulation as part of multimodal treatment provides an effective long-term treatment option for sub-group of refractory BPS.

The influence of sacral nerve stimulation on anorectal dysfunction

AIM

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.

METHOD

Systematic literature review of the effect of sacral nerve stimulation (SNS) on anorectal function.

RESULTS

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.

CONCLUSION

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

AIM

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.

METHOD

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.

RESULTS

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.

CONCLUSION

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.

Patient experience and satisfaction with sacral neuromodulation: results of a single-center sample survey

PURPOSE

Sacral neuromodulation is a well researched and successful treatment for functional bowel disorders. Indications have expanded throughout the years and various studies have been published on clinical efficacy or on technique improvement. The main goal of this retrospective study was to systematically evaluate daily experiences with this treatment and measure the long-term satisfaction of sacral neuromodulation therapy for functional bowel disorders.

METHODS

After institutional review board approval a new, self-designed postal questionnaire was sent to all patients in our center who were being treated with sacral neuromodulation. Only patients with a minimal follow-up of 1 year were included in the survey. Implantation years range from 2000 to 2007.

RESULTS

A total of 174 patients received the questionnaire regarding patient satisfaction and experience with sacral neuromodulation therapy. The response rate after reminder letter was 71.8% (n = 125) including 114 (91.2%) females. Patient satisfaction was high: 81 patients (65.3%) reported their results as very satisfying, 30 patients (24.2%) were moderately satisfied, and 13 patients (10.4%) were not satisfied. Analysis showed that patient satisfaction can be explained by both patient perception of present bowel function and their evaluation of the quality of daily life. No significant relationship was found with patient demographics, self-ascribed (co)morbidity, behavioral habits, or therapy duration. A total of 47 patients (38.2%) reported having some concerns regarding the future with sacral neuromodulation treatment. Twenty-eight patients (23.1%) reported a temporary loss of effect at any time during sacral neuromodulation therapy. Pain at the implantation site was reported by 65 patients (52.4%).

CONCLUSIONS

This study shows that patients treated with sacral neuromodulation, in general, are very satisfied. The main problems mentioned by patients are pain, loss of efficacy, and general concerns.

[Neurostimulation techniques in the therapeutic management of chronic pelvic and perineal pain]

INTRODUCTION

Neuromodulation is a nonspecific analgesic treatment whose mechanism of action has not yet been elucidated. The purpose of this article is to review the techniques and results of neuromodulation in the management of chronic pelvic and perineal pain.

MATERIAL AND METHODS

A comprehensive review of the literature was performed by searching PUBMED for articles on the various neuromodulation techniques used in the management of chronic pelvic and perineal pain.

RESULTS

Several levels of neuromodulation of the somatic nervous system have been evaluated in the management of pelvic pain: transcutaneous electrical nerve stimulation (TENS), percutaneous nerve stimulation (PNS), nerve root or nerve trunk stimulation, spinal cord stimulation. An improvement was obtained in an average of two thirds of cases, but with declining efficacy over time. The various studies were difficult to compare due to the heterogeneous study populations and very diverse endpoints. Interesting studies on the value of autonomic nervous system intervention have been described, but with no specific trials of neuromodulation.

CONCLUSION

The place of neuromodulation in the management of patients with chronic pelvic and perineal pain has yet to be defined, as it is too frequently used as a last resort. It appears important to develop and analyse this treatment modality in large-scale, randomized, prospective studies.

Biofeedback is superior to electrogalvanic stimulation and massage for treatment of levator ani syndrome

BACKGROUND & AIMS

Levator ani syndrome (LAS) might be treated using biofeedback to teach pelvic floor relaxation, electrogalvanic stimulation (EGS), or massage of levator muscles. We performed a prospective, randomized controlled trial to compare the effectiveness of these techniques and assess physiologic mechanisms for treatment.

METHODS

Inclusion criteria were Rome II symptoms plus weekly pain. Patients were categorized as "highly likely" to have LAS if they reported tenderness with traction on the levator muscles or as "possible" LAS if they did not. All 157 patients received 9 sessions including psychologic counseling plus biofeedback, EGS, or massage. Outcomes were reassessed at 1, 3, 6, and 12 months.

RESULTS

Among patients with "highly likely" LAS, adequate relief was reported by 87% for biofeedback, 45% for EGS, and 22% for massage. Pain days per month decreased from 14.7 at baseline to 3.3 after biofeedback, 8.9 after EGS, and 13.3 after massage. Pain intensity decreased from 6.8 (0-10 scale) at baseline to 1.8 after biofeedback, 4.7 after EGS, and 6.0 after massage. Improvements were maintained for 12 months. Patients with only a "possible" diagnosis of LAS did not benefit from any treatment. Biofeedback and EGS improved LAS by increasing the ability to relax pelvic floor muscles and evacuate a water-filled balloon and by reducing the urge and pain thresholds.

CONCLUSIONS

Biofeedback is the most effective of these treatments, and EGS is somewhat effective. Only patients with tenderness on rectal examination benefit. The pathophysiology of LAS is similar to that of dyssynergic defecation.

Sacral nerve stimulation for treatment of chronic intractable anorectal pain -a case report-

Despite recent methodological advancement of the practical pain medicine, many cases of the chronic anorectal pain have been intractable. A 54-year-old female patient who had a month history of a constant severe anorectal pain was referred to our clinic for further management. No organic or functional pathology was found. In spite of several modalities of management, such as medications and nerve blocks had been applied, the efficacy of such treatments was not long-lasting. Eventually, she underwent temporary then subsequent permanent sacral nerve stimulation. Her sequential numerical rating scale for pain and pain disability index were markedly improved. We report a successful management of the chronic intractable anorectal pain via permanent sacral nerve stimulation. But further controlled studies may be needed.