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

The Long-term Outcomes of Sacral Neuromodulation for Fecal Incontinence: A Single-Center Experience

BACKGROUND

Sacral neuromodulation is an effective treatment for fecal incontinence.

OBJECTIVE

To assess the long-term outcomes of sacral neuromodulation and establish the outcomes of patients with inactive devices.

DESIGN

This is an observational study of patients treated for >5 years. A positive outcome was defined as a more than 50% reduction in fecal incontinence episodes or improvement in a symptom severity score. Data were reviewed from a prospectively managed database.

SETTINGS

This study was conducted at a single tertiary referral center.

PATIENTS

Data from 74 patients (72 women) were available at long-term follow-up.

MAIN OUTCOME MEASURES

Bowel diary, St. Mark's incontinence score, and Manchester Health Questionnaire data were prospectively recorded at baseline, after percutaneous nerve evaluation, and at last follow-up.

RESULTS

Patients were analyzed in cohorts based on time since sacral neuromodulation implantation: group 1: 5 to 10 years (n = 20), group 2: >10 years (n = 35), and group 3: inactive sacral neuromodulation devices (n = 19). Median St. Mark's incontinence score and Manchester Health Questionnaire improved from baseline to last follow-up in group 1 ( p ≤ 0.05) and group 2 ( p ≤ 0.05), but in group 3, results returned to baseline levels at the last follow-up. Similarly, weekly fecal incontinence episodes improved in both active device groups at the last follow-up. However, in group 3, incontinence episodes were no different from baseline ( p = 0.722). Despite active devices, fecal urgency episodes increased at the last follow-up after >10 years since percutaneous nerve evaluation ( p ≤ 0.05). Complete continence was reported by 44% of patients, and at least a 50% improvement was seen in 77% of patients with active devices.

LIMITATIONS

This study is retrospective with some gaps in the available data at the last follow-up.

CONCLUSIONS

Sacral neuromodulation is an effective treatment for fecal incontinence in the long term, but all outcomes are adversely affected by device inactivity. Therefore, ongoing stimulation is required for continued benefit. See Video Abstract.

RESULTADOS A LARGO PLAZO DE LA NEUROMODULACIN SACRA PARA LA INCONTINENCIA FECAL EXPERIENCIA DE UN SOLO CENTRO

ANTECEDENTES:La neuromodulación sacra es un tratamiento eficaz para la incontinencia fecal.OBJETIVO:Este estudio tuvo como objetivo evaluar los resultados a largo plazo de la neuromodulación sacra y establecer los resultados de los pacientes con dispositivos inactivos.DISEÑO:Este es un estudio observacional de pacientes tratados durante más de 5 años. Un resultado positivo se definió como una reducción >50 % en los episodios de incontinencia fecal o una mejoría en la puntuación de gravedad de los síntomas. Los datos se revisaron a partir de una base de datos administrada prospectivamente.ENTERNO CLINICO:Este estudio se realizó en un solo centro de referencia terciario.PACIENTES:Los datos de 74 pacientes (72 mujeres) estaban disponibles en el seguimiento a largo plazo.PRINCIPALES MEDIDAS DE RESULTADO:Diario intestinal, puntuación de incontinencia de St. Mark y datos del Cuestionario de salud de Manchester se registraron prospectivamente al inicio, después de la evaluación de nervio periférico y en el último seguimiento.RESULTADOS:Los pacientes se analizaron en cohortes según el tiempo transcurrido desde la implantación de la neuromodulación sacra: Grupo 1: 5-10 años (n = 20), Grupo 2: >10 años (n = 35) y Grupo 3: dispositivos SNM inactivos (n = 19). La mediana de la puntuación de incontinencia de St. Mark y Questionnaire Cuestionario de salud de Manchester mejoraron desde el inicio hasta el último seguimiento en el Grupo 1 (p = < 0,05) y el Grupo 2 (p = < 0,05), pero en el Grupo 3 los resultados volvieron a los niveles iniciales en el último seguimiento. arriba. De manera similar, los episodios semanales de incontinencia fecal mejoraron en ambos grupos de dispositivos activos en el último seguimiento. Sin embargo, en el Grupo 3 los episodios de incontinencia no fueron diferentes de los basales (p = 0,722). A pesar de los dispositivos activos, los episodios de urgencia fecal aumentaron en el último seguimiento después de más de 10 años desde la evaluación del nervio periférico (p = < 0,05). Continencia completa se reportó en el 44 % de los pacientes, y al menos una mejora del 50 % en el 77 % con dispositivos activos.LIMITACIONES:Este estudio es retrospectivo con algunas vacíos en los datos disponibles en el último seguimiento.CONCLUSIONES:La neuromodulación sacra es un tratamiento eficaz para la incontinencia fecal a largo plazo, pero todos los resultados se ven afectados negativamente por la inactividad del dispositivo. Por lo tanto, se requiere estimulación continua para un beneficio continuo. (Traducción- Dr. Francisco M. Abarca-Rendon ).

Evaluation of optical tracking and augmented reality for needle navigation in sacral nerve stimulation

BACKGROUND AND OBJECTIVE

Sacral nerve stimulation (SNS) is a minimally invasive procedure where an electrode lead is implanted through the sacral foramina to stimulate the nerve modulating colonic and urinary functions. One of the most crucial steps in SNS procedures is the placement of the tined lead close to the sacral nerve. However, needle insertion is very challenging for surgeons. Several x-ray projections are required to interpret the needle position correctly. In many cases, multiple punctures are needed, causing an increase in surgical time and patient's discomfort and pain. In this work we propose and evaluate two different navigation systems to guide electrode placement in SNS surgeries designed to reduce surgical time, minimize patient discomfort and improve surgical outcomes.

METHODS

We developed, for the first alternative, an open-source navigation software to guide electrode placement by real-time needle tracking with an optical tracking system (OTS). In the second method, we present a smartphone-based AR application that displays virtual guidance elements directly on the affected area, using a 3D printed reference marker placed on the patient. This guidance facilitates needle insertion with a predefined trajectory. Both techniques were evaluated to determine which one obtained better results than the current surgical procedure. To compare the proposals with the clinical method, we developed an x-ray software tool that calculates a digitally reconstructed radiograph, simulating the fluoroscopy acquisitions during the procedure. Twelve physicians (inexperienced and experienced users) performed needle insertions through several specific targets to evaluate the alternative SNS guidance methods on a realistic patient-based phantom.

RESULTS

With each navigation solution, we observed that users took less average time to complete each insertion (36.83 s and 44.43 s for the OTS and AR methods, respectively) and needed fewer average punctures to reach the target (1.23 and 1.96 for the OTS and AR methods respectively) than following the standard clinical method (189.28 s and 3.65 punctures).

CONCLUSIONS

To conclude, we have shown two navigation alternatives that could improve surgical outcome by significantly reducing needle insertions, surgical time and patient's pain in SNS procedures. We believe that these solutions are feasible to train surgeons and even replace current SNS clinical procedures.

Effects of neuromodulation on treatment of recurrent anal fissure: A systematic review

BACKGROUND

Anal fissure is a linear tear in the distal anoderm most frequently occurring in the posterior midline. Lateral internal sphincterotomy is considered the gold standard for the treatment of this condition. To this date, several pharmacological and neuromodulatory therapies have been tried out as alternative non-invasive treatments for anal fissures, however, the efficacy of some of these methods remains to be understood.

OBJECTIVE

the primary aim of this study was to review available literature on neuromodulatory treatments for recurrent anal fissure as a potentially effective cure for this condition.

DATA SOURCES

A search was conducted among five main online databases Embase, PubMed, Web of Science, Scopus, and Scholar.

STUDY SELECTION

All published human studies in English literature addressing neuromodulation for the treatment of recurrent anal fissure were selected.

INTERVENTION

neuromodulation for the treatment of anal fissure. We chose to include all articles in which the authors stated that the procedure they performed was via neuromodulation technique, or that the described technique used in their study resembled the technique.

RESULT

Among a total of 3487 evaluated studies, seven represented the effects of neuro modulation on treatment of recurrent anal fissure, among which two were randomized controlled trials and the rest were prospective studies. A total of 186 patient were evaluated in these studies. The mean age of the participants was 46.97 ± 8.2. The average VAS score before intervention was 7.77 ± 2.13, which decreased to 0.31 ± 1.13 after intervention.

LIMITATIONS

limitations of this study include the lack of related articles, and data regarding this subject.

CONCLUSION

Posterior tibial nerve stimulation (PTNS) provides rapid pain relief and fissure healing especially in short-to mid-terms with little to no complications, however, using this treatment, symptoms of anal fissure do not improve as well as LIS, especially in the long-term.

Radiologically anatomic measurement analysis for the third sacral foramen and an efficient implantation protocol for sacral neuromodulation

AIMS

To define radiologically anatomic measurements for the S3 foramen and develop an efficient and straightforward implantation protocol for sacral neuromodulation (SNM) in a southern Chinese population.

METHODS

We retrospectively reviewed 793 adults without sacrococcygeal abnormalities or bony injury. We generated CT-derived three-dimensional volumetric models and collected radiologically anatomic measurements of S3 foramen. A multiple generalized linear regression model was applied to evaluate implantation protocol for SNM.

RESULTS

Height, weight, and sacral height were significantly different between enrolled patients based on sex (p < 0.001 for all), while age and sacral width were similar. The measurements L1, L2, A1, and A2 on both sides were similar, while based on sex, those of L1, A1, A2 showed significant differences [7.02 ± 0.90 (M) vs. 6.10 ± 0.99 cm (F) (p < 0.001); 83.05 ± 6.23 (M) vs. 82.08 ± 7.53° (F) (p = 0.005); and 13.31 ± 5.69 (M) vs. 11.97 ± 4.91° (F) (p < 0.001), respectively]. The multiple generalized linear regression model demonstrated that sex was a common independent factor for estimating L1, L2, A1, A2, while the consistency rate between the estimated model and actual measurements was poor. The measurements L1, L2, A1, and A2 were approximately 7.0 cm (M) versus 6.1 cm (F), 1.8 cm (M) versus 1.8 cm (F), 83° (M) versus 82° (F), and 13° (M) versus 12° (F), respectively.

CONCLUSIONS

This retrospective study indicates that the radiologically anatomic measurements for the S3 foramen have unique characteristics. Our study provides an efficient and straightforward implantation protocol for SNM, improving its use in China.

Critical appraisal of international guidelines for the management of fecal incontinence in adults: is it possible to define what to do in different clinical scenarios?

Fecal incontinence (FI) is a complex often multifactorial functional disorder which is associated with a significant impact on patients’ quality of life. There is a broad spectrum of symptoms, and degrees of severity and diverse patient backgrounds. Several treatment algorithms from different professional societies and experts are available in the literature. However, no consensus has been reached on several aspects of FI management. We performed a critical review of the most recently published guidelines on FI, emphasising the lack of consensus, highlighting specific topics mentioned in each of the guidelines that are not covered in the others and defining the treatment proposed in different clinical scenarios.

Progress in research of sacral nerve stimulation

Sacral nerve stimulation (SNS) is well-known as a minimally invasive treatment. Originally, it was mainly used to treat urinary system diseases such as urge urinary incontinence. Gradually, it is used to treat digestive system diseases such as fecal incontinence and chronic constipation. SNS is a method in which electrical pulse signals are sent out through pulse generators to stimulate the sacral nerve directly or indirectly, thus modulating the nerve reflex of the bladder, urethra, anus, colon, and rectum and improving abnormal nerve regulation to achieve the therapeutic effect. The regulation of the sacral nerve is often carried out by inserting electrodes into the sacral spinal canal S_2-4 (mostly S₃), and the symptoms are improved by complex regulation of spinal reflex and supraspinal reflex. However, the exact mechanism is still unclear. Many studies have shown that SNS plays a key role in the treatment of many diseases of the urinary system and digestive system. This paper reviews the progress in the research of SNS.

A Cadaveric Study on the Efficacy of Surface Marking and Bony Landmarks Used in Sacral Neuromodulation

Background

Anatomical landmarks and surface markings have long been used in out-patient contexts for conducting percutaneous nerve evaluation procedures, but studies testing the reliability of these anatomical landmarks are scant. There have been reports where the procedure has failed. Could it be possible that the anatomical landmarks that are used are not reliable enough? To answer this question, we used this study to understand the reliability of these anatomical landmarks.

Methods

Twenty cadavers, 10 males and 10 females, were dissected in the sacral region; the landmarks were tested, and the angulation and curve made by the sacral 3 (S3) nerve were also studied.

Results

Sacral 3 was identified mainly at the four o’clock position on the right and at the eight o’clock position on the left side. The Sacral 3 foramen was found at a mean distance of 9.17 ± 0.23 cm from the tip of the coccyx. The mean distance of the lateral margin of S3 from the median sacral ridge was found to be 2.16 ± 0.07 cm.

Conclusion 

The landmark of 9 cm from the coccyx tip is a valid landmark for sacral neuromodulation (SNM) procedures. The tip of the lead should follow the curve of the nerve as close as possible at the four and eight o’clock positions on the right and left side, respectively. However, the length of the coccyx differs from person to person. The proximity of the adjacent foramina to each other and the variations in the emerging of the nerve are a few factors to be considered while performing SNM procedures. Further study with a larger sample is required in order to investigate the course of the nerve, and its relationship to response to SNM.

Bowel Dysfunction in Spinal Cord Injury

PURPOSE OF REVIEW

To evaluate and report current evidence regarding the management of bowel dysfunction in spinal cord injury. There is a paucity of high-quality large studies on which to base management advice.

RECENT FINDINGS

Recent research has focused on defining the nature of symptomatology of bowel dysfunction in SCI and describing the effects on quality of life and social interactions. Technical aspects of colonoscopy have received attention, and aspects of understanding the pathophysiology in relation to both neural and non-neural dysfunction have been studied. There has been refinement and expansion of the pharmacological and non-pharmacological treatment options for bowel dysfunction in SCI. Management of bowel dysfunction in SCI requires a comprehensive and individualized approach, encompassing lifestyle, toileting routine, stimulation, diet, medications, and surgery. Further high-quality research is required to inform best practice.

Electrophysiological Basis of Fecal Incontinence and Its Implications for Treatment

The majority of patients with neuropathic incontinence and other pelvic floor conditions associated with straining at stool have damage to the pudendal nerves distal to the ischial spine. Sacral nerve stimulation appears to be a promising innovation and has been widely adopted and currently considered the standard of care for adults with moderate to severe fecal incontinence and following failed sphincter repair. From a decision-to-treat perspective, the short-term efficacy is good (70%-80%), but the long-term efficacy of sacral nerve stimulation is around 50%. Newer electrophysiological tests and improved anal endosonography would more effectively guide clinical decision making.

Peripheral and Sacral Neuromodulation in the Treatment of Neurogenic Lower Urinary Tract Dysfunction

Sacral and peripheral neuromodulation are minimally invasive surgical procedures that are third-line therapy options for the treatment of patients with idiopathic overactive bladder syndrome. There has been interest in their efficacy in the management of neurogenic lower urinary tract dysfunction (NLUTD). Contemporary data suggest promising outcomes for urinary and bowel symptoms in carefully selected patients with spinal cord injury and/or multiple sclerosis. This article reviews the current literature regarding urinary and bowel outcomes in patients with NLUTD and also discusses contemporary studies that suggest that treatment during particular stages of neurologic injury may prevent long-term urinary sequelae.

Evaluation of the axonics modulation technologies sacral neuromodulation system for the treatment of urinary and fecal dysfunction

INTRODUCTION

Sacral neuromodulation (SNM) remains one of the few effective treatments for refractory bladder and bowel dysfunction. However, SNM is associated with frequent need for surgical intervention, in many cases because of a failed battery. A rechargeable SNM system, with a manufacturer-reported battery life of 15 years or more, has entered post-market clinical testing in Europe but has not yet been approved for clinical testing in the United States. Areas covered: We review existing neuromodulation technologies for the treatment of lower urinary tract and bowel dysfunction and explore the limitations of available technology. In addition, we discuss implantation technique and device specifications and programming of the rechargeable SNM system in detail. Lastly, we present existing evidence for the use of SNM in bladder and bowel dysfunction and evaluate the anticipated trajectory of neuromodulation technologies over the next five years. Expert commentary: A rechargeable system for SNM is a welcome technological advance. However surgical revision not related to battery changes is not uncommon. Therefore, while a rechargeable system would be expected to reduce costs, it will not eliminate the ongoing maintenance associated with neuromodulation. No matter the apparent benefits, all new technologies require extensive post-market monitoring to ensure safety and efficacy.

Systematic review of the impact of sacral neuromodulation on clinical symptoms and gastrointestinal physiology

Background

Sacral neuromodulation (SNM) has emerged as a treatment option for faecal incontinence (FI). However, its objective effect on symptoms and anorectal function is inconsistently described. This study aimed to systematically review the impact of SNM on clinical symptoms and gastrointestinal physiology in patients with FI, including factors that may predict treatment outcome.

Methods

An electronic search of MEDLINE (1946–2014)/EMBASE database was performed in accordance with PRISMA guidelines. Articles that reported the relevant outcome measures following SNM were included. Clinical outcomes evaluated included: frequency of FI episodes, FI severity score and success rates. Its impact on anorectal and gastrointestinal physiology was also evaluated.

Results

Of 554 citations identified, data were extracted from 81 eligible studies. Meta‐analysis of the data was precluded due to lack of a comparison group in most studies. After permanent SNM, ‘perfect’ continence was noted in 13–88% of patients. Most studies reported a reduction in weekly FI episodes (median difference of the mean −7.0 (range: −24.8 to −2.7)) and Wexner scores (median difference of the mean −9 (−14.9 to −6)). A trend towards improved resting and squeeze anal pressures and a reduction in rectal sensory volumes were noted. Studies failed to identify any consistent impact on other physiological parameters or clinicophysiological factors associated with success.

Conclusion

SNM improves clinical symptoms and reduces number of incontinence episodes and severity scores in patients with FI, in part by improving anorectal physiological function. However, intervention studies with standardized outcome measures and physiological techniques are required to robustly assess the physiological impact of SNM.

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.

Electrical Stimulation and Motor Recovery

In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as “neurons that fire together, wire together.” This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical stimulation (FES) has long been used to activate sacral nerves to treat bladder and pelvic dysfunction and to augment motor function. In theory, FES should facilitate synaptic formation and motor recovery after regenerative therapies. Upcoming clinical trials provide unique opportunities to test the theory.

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.

Neuromodulation of perineally transposed antropylorus with pudendal nerve anastomosis following total anorectal reconstruction in humans

BACKGROUND

We have reported perineal antropyloric segment transposition with its pudendal innervation as a replacement for anal sphincter. Our aim herein was to neuromodulate this segment by electrical stimulation.

METHODS

Eight patients with a permanent colostomy underwent perineal antropyloric segment transposition followed by neural anastomosis of its anterior vagus branch to pudendal nerve branch in the perineum. Perineal antropyloric graft was assessed for its functional integrity and electrophysiological effects. Nerve stimulation was done by surface stimulation technique, using a customized stimulation protocol for smooth muscle. Antral pressures were recorded on voluntary attempts and on nerve stimulation with simultaneous concentric needle electromyography of the perineal antropylorus.

KEY RESULTS

The antral segment showed slow spontaneous contractions (2-3/min) on digital examination, endoscopy, and electrophysiology. Stimulated antropyloric electromyography showed a latency of 2-5 s with a differential rise in amplitude (mean range 58.57-998.75 μV) according to the frequency of stimulation (range 10-150 Hz). An average latency of 10 s in relation to rise in the antral pressure was observed on pudendal nerve stimulation. Triggering of the intrinsic rhythm was observed in patients where it was initially absent. Voluntary attempts at contraction also showed a rise in perineally transposed antral pressure.

CONCLUSIONS & INFERENCES

Spontaneous rhythm, its generation after electrical stimulation, and response to voluntary contraction demonstrates the viability and functional reinnervation of the perineally transposed antropyloric segment. Rise in pressure on electrical stimulation shows evidence for its neuromodulation.

Baseline factors predictive of patient satisfaction with sacral neuromodulation for idiopathic fecal incontinence

PURPOSE

Sacral neuromodulation (SNM) is an established treatment for fecal incontinence (FI). A recent study from our group found that the relationship between patient satisfaction and clinical outcome is complex and does not match the traditional used success criteria. Therefore, the ability to predict patient satisfaction must be given priority. The aim of the present study is to identify baseline factors predictive of patient satisfaction, with SNM, for idiopathic FI.

METHODS

We analyzed data from patients treated with SNM for idiopathic FI in Aarhus, Denmark, and Maastricht, The Netherlands. A questionnaire considering self-reported satisfaction was mailed to these patients and compared to baseline characteristics. Logistic regression was used to determine the predictive value of baseline demographic and diagnostic variables.

RESULTS

In total, 131 patients were included in the analysis. Patient satisfaction with the current treatment result was reported in 75 patients. Fifty-six patients were dissatisfied with SNM treatment, after median 46 months (range 11-122) with permanent implantation. Pudendal nerve terminal motor latency (PNTML) was the solely identified predictor for long-term patient satisfaction. A subgroup univariate-logistic regression analysis showed that PNTML ≤ 2.3 ms at the side of lead implantation was a statistically significant predictor for patient satisfaction (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.01-5.24, p = 0.048).

CONCLUSION

Baseline PNTML measurement may be predictive of long-term satisfaction with SNM therapy for idiopathic FI. Further studies are needed to confirm this result.

Neurostimulation for neurogenic bowel dysfunction

Background. Loss of normal bowel function caused by nerve injury, neurological disease or congenital defects of the nervous system is termed neurogenic bowel dysfunction (NBD). It usually includes combinations of fecal incontinence, constipation, abdominal pain and bloating. When standard treatment of NBD fails surgical procedures are often needed. Neurostimulation has also been investigated, but no consensus exists about efficacy or clinical use. Methods. A systematic literature search of NBD treated by sacral anterior root stimulation (SARS), sacral nerve stimulation (SNS), peripheral nerve stimulation, magnetic stimulation, and nerve re-routing was made in Pubmed, Embase, Scopus, and the Cochrane Library. Results. SARS improves bowel function in some patients with complete spinal cord injury (SCI). Nerve re-routing is claimed to facilitate defecation through mechanical stimulation of dermatomes in patients with complete or incomplete SCI or myelomeningocele. SNS can reduce NBD in selected patients with a variety of incomplete neurological lesions. Peripheral stimulation using electrical stimulation or magnetic stimulation may represent non-invasive alternatives. Conclusion. Numerous methods of neurostimulation to treat NBD have been investigated in pilot studies or retrospective studies. Therefore, larger controlled trials with well-defined inclusion criteria and endpoints are recommended before widespread clinical use of neurostimulation against NBD.

Functional results and patient satisfaction with sacral nerve stimulation for idiopathic faecal incontinence

AIM

Sacral nerve stimulation (SNS) is an established treatment for faecal incontinence (FI) when conservative modalities have failed to restore continence. This two-centre study aimed to document functional outcome and its relationship to patient satisfaction.

METHOD

Patients treated with SNS for idiopathic FI in Aarhus (Denmark) and Maastricht (The Netherlands) were included. At the most recent follow-up appointment, 127 patients (80%) were identified as receiving active SNS therapy. A questionnaire considering bowel habits, quality of life, and self-reported satisfaction and a 3-week bowel-habit diary were mailed to these patients, and 85% responded.

RESULTS

Patient satisfaction was clearly related to the number of FI episodes. Patients experiencing full continence were all satisfied, and although the satisfaction rate decreased as the number of FI episodes increased, 46% of the patients with more FI episodes at follow-up than at baseline were still satisfied. Per-protocol analysis resulted in a satisfaction rate of 57.3%. In total, 74.7% of the patients receiving active SNS therapy reported a reduction of ≥ 50% in FI episodes, 10.3% of whom were dissatisfied after a median of 46 months of follow-up.

CONCLUSION

There is a clear relationship between patient satisfaction and improved continence. A total of 57.3% of the patients offered SNS therapy were satisfied at follow-up. However, 46% of the patients with more FI episodes at follow-up than at baseline were also satisfied. Therefore, functional outcome of SNS therapy cannot be based only on bowel-habit diaries and bowel scores.

Pancolonic motor response to subsensory and suprasensory sacral nerve stimulation in patients with slow-transit constipation

BACKGROUND

Sacral nerve stimulation (SNS) is emerging as a potential treatment for patients with constipation. Although SNS can elicit an increase in colonic propagating sequences (PSs), the optimal stimulus parameters for this response remain unknown. This study evaluated the colonic motor response to subsensory and suprasensory SNS in patients with slow-transit constipation.

METHODS

Patients with confirmed slow-transit constipation were studied. Either a water-perfused manometry catheter or a high-resolution fibre-optic manometry catheter was positioned colonoscopically to the caecum. A temporary electrode was implanted transcutaneously in the S3 sacral nerve foramen. In the fasted state, three conditions were evaluated in a double-blind randomized fashion: sham, subsensory and suprasensory stimulation. Each 2-h treatment period was preceded by a 2-h basal period. The delta (Δ) value was calculated as the frequency of the event during stimulation minus that during the basal period.

RESULTS

Nine patients had readings taken with a water-perfused catheter and six with a fibre-optic catheter. Compared with sham stimulation, suprasensory stimulation caused a significant increase in the frequency of PSs (mean(s.d.) Δ value - 1·1(7·2) versus 6·1(4·0) PSs per 2 h; P = 0·004). No motor response was recorded in response to subsensory stimulation compared with sham stimulation. Compared with subsensory stimulation, stimulation at suprasensory levels caused a significant increase in the frequency of PSs (P = 0·006).

CONCLUSION

In patients with slow-transit constipation, suprasensory SNS increased the frequency of colonic PSs, whereas subsensory SNS stimulation did not. This has implications for the design of therapeutic trials and the clinical application of the device.

Sacral nerve modulation for defaecation and micturition disorders in patients with spina bifida

AIM

Sacral nerve modulation is a well accepted method for the treatment of defaecation disorders and voiding dysfunction. Results of sacral nerve modulation in patients with spinal cord lesions are not well assessed, but preliminary results look poor. Therefore, the purpose of this study was to assess the effectiveness of sacral nerve modulation for defaecation disorders and voiding dysfunction in patients with spina bifida.

METHOD

Consecutive patients with spina bifida suffering from a myelomeningocele and combined faecal and urinary functional disorders that were eligible for peripheral nerve evaluation (PNE) were studied. A permanent sacral nerve modulation implantation was performed after successful PNE.

RESULTS

Ten patients (four female) were included in this study with a median age of 26.4 (range 11.1-41.0) years. In two the PNE was not possible. The median faecal incontinence days (6.0 vs 3.5) and episodes (8.5 vs 3.5) per 21 days decreased significantly during the 3-week period of PNE (P = 0.033). Only 3/10 (30%) patients had a more than 50% improvement and proceeded to a permanent sacral nerve modulation implantation. In one patient it was not possible to perform the permanent implant.

CONCLUSION

Preliminary results of sacral nerve modulation in a subgroup of spina bifida patients with combined faecal and urinary functional disorders look promising, but long-term results in larger patient groups need to be studied.

Efficacy of sacral nerve stimulation for the treatment of fecal incontinence

BACKGROUND

Sacral nerve stimulation has been shown to be an effective treatment for fecal incontinence and early studies reported success rates of 67% to 100%. However, "success" has been arbitrarily set at a 50% reduction in symptoms, and data are rarely reported with "intention to treat."

OBJECTIVE

This study aimed to assess the true efficacy of sacral nerve stimulation for fecal incontinence compared with the published literature.

DESIGN

This prospective 5-year study was conducted to assess 50 patients with fecal incontinence treated with sacral nerve stimulation. All analyses were performed on an intention-to-treat basis.

SETTINGS

This study took place in a single tertiary referral colorectal department.

PATIENTS

Fifty consecutive patients with fecal incontinence refractory to conservative management were included in the study.

INTERVENTIONS

The interventions performed were temporary evaluation with or without permanent sacral nerve stimulation.

MAIN OUTCOME MEASURES

: Primary outcome measures were 1) attainment of continence, 2) reduction in fecal incontinence episodes, 3) improvement in Cleveland Clinic Fecal Incontinence scores, and 4) improvement in the ability to defer defecation.

RESULTS

Thirteen patients (26%) did not respond at the temporary evaluation stage or were dissatisfied with the result. Ten further patients (20%) did not achieve a 50% reduction in symptoms following permanent implantation. The median follow-up was 17 months (range, 2-55), at which time 27 patients (54%) experienced a 50% or more reduction in symptoms, including 13 (26%) who achieved apparent continence. Median fecal incontinence episodes per fortnight reduced from 14 (range, 0-53) to 2 (range, 0-20; P < .0001). Median Cleveland Clinic Fecal Incontinence scores reduced from 15 (range, 3-20) to 8 (range, 0-17; P < .0001). The ability to defer defecation improved significantly (P < .0001). These results compare favorably with the published literature.

LIMITATIONS

Quality of life was not assessed.

CONCLUSIONS

This study demonstrates that sacral nerve stimulation can be an effective treatment for patients with fecal incontinence; however, when analyzed by intention to treat, the symptoms of fecal incontinence continue in the majority (74%) of patients.

Progress in understanding the role of neuromodulation in the pathogenesis of functional gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs) are a group of common digestive diseases whose pathogenesis is closely related to the abnormal brain-gut axis. Disturbances of the neuromodulatory processes in the brain-gut axis generate functional digestive disorders mainly centered on the pain, bloating symptoms and motility diseases. This article reviews neuromodulatory mechanism aspects of the brain-gut axis and discusses the clinical prospects for the neuromodulatory interventional treatment of FGIDs.

Temporary sacral nerve stimulation alters rectal sensory function: a physiological study

BACKGROUND

The indications for sacral nerve stimulation are increasing, but the mechanism remains poorly understood.

OBJECTIVE

This study aimed to examine the effect of sacral nerve stimulation on rectal compliance and rectal sensory function.

DESIGN

This was a prospective study.

SETTINGS

This study took place at a university teaching hospital.

PATIENTS

Twenty-three consecutive consenting patients (22 female; median age, 49 y) undergoing temporary sacral nerve stimulation for fecal incontinence were prospectively studied. Clinical response was assessed by the use of bowel diaries and Wexner scores.

MAIN OUTCOME MEASURES

Anal manometry, rectal compliance, volume and pressure thresholds to rectal distension (barostat), and rectal Doppler mucosal blood flow were measured before and at the end of stimulation.

RESULTS

Sixteen patients (70%) had a favorable clinical response. Median anal squeeze pressures increased with stimulation from 40 (range, 6-156) cmH2O to 64 (range, 16-243) cmH2O. Median rectal compliance did not significantly change with stimulation (prestimulation: 11.5 (range, 7.9-21.8) mL/mmHg, poststimulation: 12.4 (range, 6.2-22) mL/mmHg, P = .941). Rectal wall pressures associated with urge (baseline: 15.4 (range, 11-26.7) mmHg, poststimulation: 19 (range, 11.1-42.7) mmHg, P = .054) and maximal tolerated thresholds (baseline: 21.6 (8.5-31.9) mmHg, poststimulation: 27.1 (14.3-43.3) mmHg, P = .023) significantly increased after stimulation. Rectal Doppler mucosal blood flow did not significantly change with stimulation (baseline: 125.8 (69.9-346.8), poststimulation: 112.4 (50.2-404.1), P = .735). Changes in anal resting pressure and rectal wall pressures with stimulation were evident only in responders; however, changes in anal squeeze pressures were evident in both responders and nonresponders.

LIMITATIONS

The study reports results following short-term stimulation in a small but homogenous group of patients. A larger long-term study will follow.

CONCLUSION

Temporary sacral nerve stimulation does not change rectal compliance, but is associated with significant changes to the pressure thresholds of rectal distension. This, together with the observation that outcome is not related to sphincter integrity, supports the hypothesis of an afferent-mediated mechanism of action.

The influence of sacral nerve stimulation on gastrointestinal motor function in patients with fecal incontinence

BACKGROUND

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence of various etiologies. However, the mechanism of action remains unclear. The aim of the present study was to determine whether SNS affects gastric emptying, small intestinal transit or colonic transit times.

METHODS

Seven patients with a permanently implanted sacral nerve stimulator participated in a double-blind randomized cross-over study. The patients were allocated to stimulation ON or OFF for two 7-day periods separated by at least 1week. On days 4-7 of each 7-day period, the patients were examined by gamma camera imaging to measure gastric emptying, small intestinal transit and colonic transit parameters of a radiolabeled, 1600 kJ mixed solid and liquid meal ingested on day 4.

KEY RESULTS

Sacral nerve stimulation did not change gastric retention at 15 min, gastric mean emptying time, gastric half emptying time, small intestinal mean transit time or colonic geometric center after 24, 48 and 72 h.

CONCLUSIONS & INFERENCES

  Sacral nerve stimulation does not induce major changes in the propulsive capacity of the gastrointestinal tract in patients successfully treated for fecal incontinence with permanent sacral nerve stimulator.

Neuromodulation for constipation: sacral and transcutaneous stimulation

Constipation is a frequently occurring digestive ailment that is usually treated conservatively. Neuromodulation is altering function of an organ by altering neural activity. This paper reviews methods of neuromodulation used to treat constipation. This includes direct stimulation of sacral nerves and stimulation across the skin. Direct stimulation of sacral nerves is the most well developed method and is presented in detail. It is generally accepted that the mechanism of action is modulation rather than stimulation so it is called sacral neuromodulation (SNM). SNM involves percutaneous placement of an electrode in the third sacral foramen and implanting a stimulating device under the skin in the buttocks. SNM is founded on the physiological principle that activity in one neural pathway modulates pre-existing activity in another through synaptic interaction. The mechanism of action in constipation may be neuromodulation of the extrinsic neural control of the large bowel or modulation of reflexes inhibiting large bowel function. Limited evidence is available to assess the outcome of SNM in constipation. Results in the medium term seem promising for selected patients with idiopathic slow and normal transit constipation not responding to optimal conservative treatment. Adverse events include electrode migration and infection. The availability of a testing phase provides a predictor of treatment outcome. In addition, transcutaneous stimulation using sticky pad electrodes over the lumbosacral region or acupuncture points has been reported to improve constipation symptoms. In general, the level of evidence is low and further studies are needed.

New selective endoscopic sacral nerve root stimulation--an advance in the treatment of fecal incontinence

BACKGROUND

Fecal incontinence (FI) is a major part of illness and physical discomfort in the general population. Since the 1990s, sacral nerve stimulation has been well established in the treatment of neurogenic FI. The precise placement of the electrode is crucial for the success of the procedure. Eighty percent of the patients benefit from permanent treatment, but in 10-20% of the patients tested electrode placement proves impossible due to anatomical variations of the sacral foramina. In this study, we describe the technical requirements and a new method of electrode placement with reference to the anatomical (bone) landmarks in an animal model.

METHODS

With a small endoscope (Verres needle), we accessed the perirectal space to identify the nervous structures. A stimulated sphincter EMG was obtained for the experimental animals and muscle action potential (MAP/M-wave), latency time [ms], and the amplitude of the motor response [μV] were recorded. Electrodes were placed, the animals killed and dissected leaving the pelvic cavity untouched. The specimens were examined in a magnetic resonance scanner and in a multi-slice computed tomography scanner to detect the electrode material and possible surgical complications. After that the specimens were dissected.

KEY RESULTS

In all eight cases in the four animals tested, we were able to stimulate the sacral nerve as demonstrated by the EMG findings. No major surgical complications were observed for the procedure.

CONCLUSIONS & INFERENCES

Endoscopic sacral nerve root stimulation is a safe and effective method for delivering stimulation material in the pelvis of the sheep. It is a promising procedure to be tested in humans.

Sacral nerve modulation in overactive bladder

This article represents a general overview of therapies for urinary urgency, frequency, and overactive bladder, with specific emphasis on sacral neuromodulation. The history of sacral neuromodulation is discussed along with an update of the current literature. Future directions for neuromodulation of the pelvic floor also are discussed.

Transcutaneous electrical posterior tibial nerve stimulation for faecal incontinence: effects on symptoms and quality of life

PURPOSE

Faecal incontinence is a disabling symptom which may be particularly difficult to treat. Recent studies showed that transcutaneous electrical posterior tibial nerve stimulation may improve faecal continence. In this study, we aimed to evaluate the effectiveness of this technique and tried to individualize predictive factors of success.

METHODS

Twenty-four patients suffering from faecal incontinence were treated 20 min per day by applying transcutaneous electrical posterior tibial nerve stimulation for 3 months. A clinical evaluation was performed at the end of treatment, with Wexner's score and analogical scales for symptoms. After 3 months, if the treatment was successful, patients were proposed to continue on the treatment. Predictive factors such as age, symptom duration, proctologic history, obstetrical history, ano-rectal manometric data and quality-of-life score were also analysed.

RESULTS

At 3 months, 13 patients (54%) reported a significant symptomatic improvement with a significant modification in the Wexner's score (14 vs 12, p < 0.025). At a median follow-up of 15 months, there were still 11 patients whose condition was improved.

CONCLUSION

This study shows encouraging mid-term results, and even if further randomized studies are necessary, transcutaneous electrical posterior tibial nerve stimulation may be a new and easy-to-use therapeutic option to treat faecal incontinence.

Sacral nerve stimulation for the treatment of fecal incontinence

The use of sacral nerve stimulation as a treatment for fecal incontinence for intact but functionally deficient sphincter and pelvic floor musculature, as well as for some sphincter injuries, is an attractive concept that is currently undergoing clinical trials in the United States. Electrical stimulation of the peripheral nerve supply to the striated anal sphincter muscles at the level of the sacral spinal nerves exploits the accessibility of the most distal common location of the dual peripheral nerve supply to these muscles. While the mechanism of sacral nerve stimulation's salutary effect remains conjectural at present and is likely multifactorial, current experimental data point toward both an enhancement in striated muscular activity as well as neuromodulation of sacral reflexes that regulate rectal sensitivity and contractility.

Six years of experience with sacral nerve stimulation for fecal incontinence

PURPOSE

Sacral nerve stimulation is one of many new surgical modalities for fecal incontinence. Short-term results from sacral nerve stimulation have been more encouraging than those from other modalities. The aim of this study was to report the outcome of percutaneous nerve evaluation tests and sacral nerve stimulation for the treatment of fecal incontinence from a single center covering a period of 6 years since the procedure was introduced.

METHODS

All of the candidates for a percutaneous nerve evaluation test and sacral nerve stimulation seen at our anal physiology unit between March 2001 and March 2007 were included in the study.

RESULTS

A total of 177 patients with fecal incontinence (160 females), median age 59.5 (range, 27-88) years, underwent a percutaneous nerve evaluation test. Of these patients, 142 (80%) had a positive test, including 21 of 25 (84%) patients who required a repeat percutaneous nerve evaluation test. Because of a functional failure, 16 patients underwent a revision of the permanent electrode, 7 of whom (44%) were satisfied with the functional result after the revision. Of 126 patients, 15 (12%) have undergone an explantation, with an infection rate of only 1.6%. Overall, after a median follow-up of 24 (range, 3-72) months, the median Wexner incontinence score decreased from 16 (range, 6-20) to 10 (range, 0-20) (P < .0001). In the 10 patients who underwent at least 6 years of treatment, the effect was sustained, as the median Wexner incontinence score decreased from 20 (range, 12-20) to 7 (range, 2-11) (P < .0001).

CONCLUSION

Sacral nerve stimulation is a simple, safe, and minimally invasive technique with low morbidity and excellent results, which appear to be maintained for the first 6 years after the procedure. For patients who underwent the treatment, median Wexner incontinence score decreased significantly after a median follow-up of 24 (range, 3-72) months. Twelve percent were explanted. The infection rate was 1.6%.

Sacral nerve stimulation for faecal incontinence: response rate, satisfaction and the value of preoperative investigation in patient selection

OBJECTIVE

Before undergoing sacral nerve stimulation (SNS) for faecal incontinence (FI), patients are investigated with morphologic, dynamic and electrophysiologic tests. The purpose of our study was to evaluate their value in the selection of patients who may benefit most from neuromodulation.

METHOD

If temporary stimulation resulted in a good objective response, a permanent neuromodulator was implanted. Patients were reviewed at 3 months and then at 6 monthly intervals. Asked by telephone, patient's satisfaction was described as good, satisfactory or poor.

RESULTS

Forty-five consecutive patients (41 females, median age 59 years) with FI (Wexner 16.1 +/- 2.9) underwent SNS. Temporary stimulation was successful in 32 (71)% patients. At a median follow-up of 33 months, the neuromodulator remained in place in 25 (55%) patients, two do whom switched it off, leaving 23 (51%) with a functioning neuromodulator. There was no statistically significant difference between the characteristics (including manometry, ultrasound and electrophysiology) of patients undergoing implantation (n = 32) or not (n = 13) and those with or without a functioning stimulator (n = 23: n = 13). In the 23 patients with a functioning stimulator the result was good in 12, satisfactory in five and poor in six. There was no statistically significant difference in the patient characteristics between those with a good result (n = 12) and the remainder (n = 32).

CONCLUSION

The findings suggest that investigation for FI does not facilitate patient selection for SNS and cannot be used to predict outcome.

Sympathetic and parasympathetic regulation of rectal motility in rats

INTRODUCTION

The colon and rectum are regulated by the autonomic nervous system (ANS). Abnormalities of the ANS are associated with diseases of the colon and rectum while its modulation is a putative mechanism for sacral nerve stimulation. The purpose of this study is to establish a rat model elucidating the role of the efferent ANS on rectal motility.

MATERIALS AND METHODS

Rectal motility following transection or stimulation of parasympathetic pelvic nerves (PN) or sympathetic hypogastric nerves (HGN) was measured with rectal strain gauge transducers and quantified as a motility index (MI). Colonic transit was measured 24 hours after transection by calculating the geometric center (GC) of distribution of (51)Cr

RESULTS AND DISCUSSION

Transection of PN and HGN decreased MI to 518 +/- 185 g*s (p < 0.05) and increased MI to 5,029 +/- 1,954 g*s (p < 0.05), respectively, compared to sham (975 +/- 243 g*s). Sectioning of PN and HGN decreased transit with GC = 4.9 +/- 0.2 (p < 0.05) and increased transit with GC = 8.1 +/- 0.7 (p < 0.02), respectively, compared to sham (GC = 5.8 +/- 0.3). Stimulation of PN and HGN increased MI to 831 +/- 157% (p < 0.01) and decreased MI to 251 +/- 24% (p < 0.05), respectively.

CONCLUSION

Rectal motility is significantly altered by sectioning or stimulating either HGN or PN. This model may be useful in studying how sacral nerve stimulation exerts its effects and provide insight into the maladies of colonic motility.

Function and dysfunction of the colon and anorectum in adults: working team report of the Swedish Motility Group (SMoG)

Symptoms of fecal incontinence and constipation are common in the general population. These can, however, be unreliably reported and are poorly discriminatory for underlying pathophysiology. Furthermore, both symptoms may coexist. In the elderly, fecal impaction always must be excluded. For patients with constipation, colon transit studies, anorectal manometry and defecography may help to identify patients with slow-transit constipation and/or pelvic floor dysfunction. The best documented medical treatments for constipation are the macrogols, lactulose and isphagula. Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. Surgery is restricted for a highly selected group of patients with severe slow-transit constipation and for those with large rectoceles that demonstrably cause rectal evacuatory impairment. For patients with fecal incontinence that does not resolve on antidiarrheal treatment, functional and structural evaluation with anorectal manometry and endoanal ultrasound or magnetic resonance (MR) of the anal canal may help to guide management. Sacral nerve stimulation is a rapidly evolving alternative when other treatments such as biofeedback and direct sphincter repair have failed. Advances in understanding the pathophysiology as a guide to treatment of patients with constipation and fecal incontinence is a continuing important goal for translational research. The content of this article is a summary of presentations given by the authors at the Fourth Meeting of the Swedish Motility Group, held in Gothenburg in April 2007.

Neuromodulation for functional bowel disorders

In patients with functional bowel disorders not responding to maximal medical treatment, bowel lavage or biofeedback therapy, can nowadays be treated by sacral nerve neuromodulation (SNM). SNM therapy has evolved as a treatment for faecal incontinence and constipation. The exact working mechanism remains unknown. It is known that SNM therapy causes direct stimulation of the anal sphincter and causes changes in rectal sensation and several central nervous system areas. The advantage of SNM therapy is the ability to do a minimally invasive temporary screening phase to assess permanent stimulation outcome. Ideal candidates for SNM therapy are not known. Several studies have described positive and negative predictive factors, but the temporary screening remains the instrument of choice. Clinical results are good and as the technique is developing, fewer complications occur. New indications for SNM include constipation and anorectal or pelvic pain.

Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double-blind sham-controlled study

Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short-term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min(-1) for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high-amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8-39) after Bisacodyl administration during active stimulation compared to 14 min (range 5-40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl-induced colonic contractions.

Transcutaneous posterior tibial nerve stimulation for fecal incontinence in inflammatory bowel disease patients: a therapeutic option?

BACKGROUND

Fecal incontinence associated with inflammatory bowel disease (IBD) may be particularly difficult to treat. Two recent studies showed that transcutaneous posterior tibial nerve stimulation may improve fecal continence. In this pilot study, we tested the usefulness of this noninvasive technique to treat fecal incontinence in IBD.

METHODS

Twelve patients with IBD (7 Crohn's disease, 2 undetermined colitis, 3 ulcerative colitis) were treated by applying transcutaneous posterior tibial nerve electrical stimulation daily for 3 months. A clinical evaluation was performed at the end of treatment, with Wexner's score and Harvey-Bradshaw index and analog scales to assess symptoms and quality of life.

RESULTS

At 3 months, 5 patients (41.6%) reported a significant symptomatic and quality of life improvement, although only 1 reported a significant modification in the Wexner score.

CONCLUSION

These preliminary results are encouraging, although further studies are necessary. Posterior tibial nerve electrical stimulation may represent a new therapeutic option to treat the difficult problem of fecal incontinence in patients with IBD.

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

BACKGROUND

Chronic idiopathic anal pain is a common, benign symptom, the etiology of which remains unclear. Traditional treatments are often ineffective. This study investigated the efficacy of sacral nerve stimulation in treating chronic idiopathic anal pain.

METHODS

Twelve patients (10 women and 2 men; mean age, 61.0 +/- 10.3 years; range, 48-82 years) implanted with a permanent device for sacral nerve stimulation were followed in the Italian Group for Sacral Neuromodulation (GINS) Registry. All patients had frequent chronic anal or perianal pain; 75 percent had previously undergone pelvic surgery. Pharmacologic and rehabilitative therapy had yielded poor results. Changes from baseline to last follow-up examination were evaluated for scores on a visual analog pain scale (0-10) and the Short-Form 36 (SF-36) health status questionnaire. Manometric measurements recorded at last follow-up were compared with preimplantation values.

RESULTS

In one patient, the permanent device was removed because of technical failure. After a mean follow-up of 15 (range, 3-80) months, visual analog pain scores had significantly improved (from 8.2 +/- 1.7 to 2.2 +/- 1.3, P < 0.001). SF-36 physical component scores increased from 26.27 +/- 5.65 to 38.95 +/- 9.08, P < 0.02). Scores on the mental component showed improvement, although not significant. Postimplantation changes in manometric functional data were not significant, but sensitivity thresholds showed a considerable decrease.

CONCLUSIONS

Long-term follow-up data showing improvements in scores on the visual analog pain scale and quality of life questionnaire indicate that, before adopting more aggressive surgical procedures, SNS should be considered for patients with chronic idiopathic anal pain in whom pharmacologic and biofeedback treatments have failed to produce effective results.

Surgery and sacral nerve stimulation for constipation and fecal incontinence

Fecal continence is a complex bodily function, which requires the interplay of sensation, rectal capacity, and anal neuromuscular function. Fecal incontinence affects approximately 2% of the population and has a prevalence of 15% in elderly patients. Constipation is one of the most common gastrointestinal disorders. The variety of symptoms and risk factors suggest a multifactorial origin. Before any invasive intervention, the surgeon should have a thorough understanding of the etiology of these conditions. Appropriate medical management can improve symptoms in the majority of patients. Surgery is indicated when all medical possibilities are exhausted. This review discusses the most used surgical procedures emphasizing the latest experiences. Sacral nerve stimulation (SNS) is a promising option for patients with fecal incontinence and constipation. The procedure affords patients improved continence and quality of life. The mechanism of action is still poorly understood. This treatment has been used before in other more invasive surgical procedures or even after their failure to improve patients' symptoms and avoid a definitive stoma. Before any invasive intervention, the surgeon should have a thorough understanding of the etiology of these conditions. Appropriate medical management can improve symptoms in the majority of patients. Surgery is indicated when all medical possibilities are exhausted. This review discusses the most used surgical procedures emphasizing the latest experiences. Sacral nerve stimulation (SNS) is a promising option for patients with fecal incontinence and constipation. The procedure affords patients improved continence and quality of life. The mechanism of action is still poorly understood. This treatment has been used before in other more invasive surgical procedures or even after their failure to improve patients' symptoms and avoid a definitive stoma.

Neuromodulatory processes of the brain-gut axis

Brain-gut axis represents a complex reflex circuit that integrates the communication between cortex and the digestive system. Disturbances of the neuromodulatory processes in the brain-gut axis generate functional digestive disorders mainly centered on the pain symptoms and motility disorders. This article reviews structural and patho-physiological aspects of the brain-gut axis and explains how the neuromodulatory interventions currently used in order to treat GI conditions related to the brain-gut axis disturbances. The neuromodulation can be realized by pharmacological targeting mainly receptors in the periphery or using electrical stimulation applied at different levels of the nervous system or directly in the muscular layers of the bowels resulting in modulation of the digestive system activity. The efficacy of the methods using electrostimulation is dependent on the parameters of the physical system used: amplitude, frequency, burst time of the electrical current and also the positioning of the electrodes. While pharmacological interventions are largely used at the moment, neuromodulatory interventions involving electrical stimulation showed clinical efficacy in research trials and have promise.

Sacral nerve stimulation for fecal incontinence: external anal sphincter defect vs. intact anal sphincter

PURPOSE

This prospective study was designed to assess the effectiveness of sacral nerve stimulation for fecal incontinence in patients with external anal sphincter defect and to evaluate its efficacy regarding presence and size of sphincter defect.

METHODS

Fifty-three consecutive patients who underwent sacral nerve stimulation for fecal incontinence were divided into two groups: external anal sphincter defect group (n = 21) vs. intact sphincter group (n = 32). Follow-up was performed at 3, 6, and 12 months with anorectal physiology, Wexner's score, bowel diary, and quality of life questionnaires.

RESULTS

The external anal sphincter defect group (defect <90 degrees:defect 90 degrees-120 degrees = 11:10) and intact sphincter group were comparable with regard to age (mean, 63 vs. 63.6) and sex. Incidence of internal anal sphincter defect and pudendal neuropathy was similar. All 53 patients benefited from sacral nerve stimulation. Weekly incontinent episodes decreased from 13.8 to 5 (P < 0.0001) for patients with external anal sphincter defects and from 6.7 to 2 (P = 0.001) for patients with intact sphincter at 12-month follow-up. Quality of life scores improved in both groups (P < 0.0125). There was no significant difference in improvement in functional outcomes after sacral nerve stimulation between patients with or without external anal sphincter defects. Clinical benefit of sacral nerve stimulation was similar among patients with external anal sphincter defects, irrespective of its size. Presence of pudendal neuropathy did not affect outcome of neurostimulation.

CONCLUSIONS

Sacral nerve stimulation for fecal incontinence is as effective in patients with external anal sphincter defects as those with intact sphincter and the result is similar for defect size up to 120 degrees of circumference.