Consenso Baiona sobre Incontinencia Fecal: Asociación Española de Coloproctología / Baiona's Consensus Statement for Fecal Incontinence. Spanish Association of Coloproctology

La incontinencia fecal (IF) constituye un importante problema sanitario, tanto a nivel individual como para los diferentes sistemas de salud, lo que origina una preocupación generalizada para su resolución o, al menos, disminuir en lo posible los numerosos efectos indeseables que provoca, al margen del elevado gasto que ocasiona. Existen diferentes criterios relacionados con las pruebas diagnósticas a realizar, y lo mismo acontece con relación al tratamiento más adecuado, dentro de las numerosas opciones que han proliferado durante los últimos años, no siempre basadas en una rigurosa evidencia científica. Por dicho motivo, desde la Asociación Española de Coloproctología (AECP) nos propusimos elaborar un Consenso que sirviese de orientación a todos los profesionales sanitarios interesados en el problema, conscientes, no obstante, de que la decisión terapéutica debe tomarse de manera individualizada: características del paciente/experiencia del terapeuta. Para su elaboración optamos por la técnica de grupo nominal. Los niveles de evidencia y los grados de recomendación se establecieron de acuerdo a los criterios del Oxford Centre for Evidence-Based Medicine. Por otra parte, en cada uno de los ítems analizados se añadieron, de forma breve, recomendaciones de los expertos.(AU)

Faecal incontinence (FI) is a major health problem, both for individuals and for health systems. It is obvious that, for all these reasons, there is widespread concern for healing it or, at least, reducing as far as possible its numerous undesirable effects, in addition to the high costs it entails. There are different criteria for the diagnostic tests to be carried out and the same applies to the most appropriate treatment, among the numerous options that have proliferated in recent years, not always based on rigorous scientific evidence. For this reason, the Spanish Association of Coloproctology (AECP) proposed to draw up a Consensus to serve as a guide for all health professionals interested in the problem, aware, however, that the therapeutic decision must be taken on an individual basis: patient characteristics/experience of the care team. For its development it was adopted the Nominal Group Technique methodology. The Levels of Evidence and Grades of Recommendation were established according to the criteria of the Oxford Centre for Evidence-Based Medicine. In addition, expert recommendations were added briefly to each of the items analysed.(AU)

Is magnetic anal sphincter augmentation still an option in fecal incontinence treatment: a systematic review and meta-analysis.

PURPOSE: Magnetic anal sphincter (MAS) augmentation is a novel surgical option for the treatment of fecal incontinence. Current clinical evidence is conflicting. The purpose of this meta-analysis was to report the safety profile, potential benefits, and the functional efficacy of this device. METHODS: The study followed the PRISMA guidelines. Literature databases (Medline, Scopus, Web of Science, CENTRAL) were screened for eligible articles. The primary endpoint was the pooled effect of MAS in the Cleveland Clinic Incontinence Score (CCIS) score. Quality evaluation was based on the ROBINS-I and Risk of Bias 2 tool. RESULTS: Overall, 8 studies with 205 patients were included. MAS resulted in a significant reduction of CCIS values (p = 0.019), and improvement only in the embarrassment domain of FIQoL scores (p = 0.034). The overall morbidity rate was 61.8%. Postoperative adverse events included MAS explantation in 12%, infection in 5.1%, pain in 10% and obstructed defecation in 5.8% of patients. CONCLUSION: The application of MAS in patients with fecal incontinence results in the improvement of some clinical parameters with a notable morbidity rate. Due to several study limitations, further, high-quality RCTs are required to delineate the efficacy and safety of MAS.

Mental health disorders as a risk factor in young patients with rectal prolapse.

BACKGROUND: Rectal prolapse (RP) typically presents in the elderly, though it can present in younger patients lacking traditional risk factors. The current study compares medical and mental health history, presentation, and outcomes for young and older patients with RP. METHODS: This is a single-center retrospective review of patients who underwent abdominal repair of RP between 2005 and 2019. Individuals were dichotomized into two groups based on age greater or less than 40 years. RESULTS: Of 156 patients, 25 were < 40. Younger patients had higher rates of diagnosed mental health disorders (80% vs 41%, p < 0.001), more likely to take SSRIs (p = .02), SNRIs (p = .021), anxiolytics (p = 0.033), and antipsychotics (p < 0.001). Younger patients had lower preoperative incontinence but higher constipation. Both groups had low rates of recurrence (9.1% vs 11.6%, p = 0.73). CONCLUSIONS: Young patients with RP present with higher concomitant mental health diagnoses and represent unique risk factors characterized by chronic straining compared to pelvic floor laxity.

Robotic-assisted laparoscopic Malone appendicostomy: a 6-year perspective.

PURPOSE: A robotic-assisted laparoscopic approach to appendicostomy offers the benefits of a minimally invasive approach to patients who would typically necessitate an open procedure, those with a larger body habitus, and those requiring combined complex colorectal and urologic reconstructive procedures. We present our experience performing robotic-assisted appendicostomies with a focus on patient selection, perioperative factors, and functional outcomes. METHODS: A retrospective review of patients who underwent a robotic-assisted appendicostomy/neoappendicostomy at our institution was performed. RESULTS: Twelve patients underwent robotic-assisted appendicostomy (n = 8) and neoappendicostomy (n = 4) at a range of 8.8-25.8 years. Five patients had a weight percentile > 50% for their age. Seven patients underwent combined procedures. Median operative time for appendicostomy/neoappendicostomy only was 185.0 min. Complications included surgical site infection (n = 3), stricture requiring minor operative revision (n = 2), conversion to an open procedure due to inadequate appendiceal length (prior to developing our technique for robotic neoappendicostomies; n = 1), and granuloma (n = 1). At a median follow-up of 10.8 months (range 1.7-74.3 months), 91.7% of patients were consistently clean with antegrade enemas. DISCUSSION: Robotic-assisted laparoscopic appendicostomy and neoappendicostomy with cecal flap is a safe and effective operative approach. A robotic approach can potentially overcome the technical difficulties encountered in obese patients and can aid in patients requiring both a Malone and a Mitrofanoff in a single, combined minimally invasive procedure.

Anal defecatory function in ulcerative colitis patients after total proctocolectomy and ileal pouch-anal anastomosis: a prospective cohort study.

BACKGROUND: Total proctocolectomy (TPC) followed by ileal pouch-anal anastomosis (IPAA) remains the only viable option whenever different treatment modalities fail in patients with ulcerative colitis (UC). OBJECTIVE: Prospective cohort pre/post study examining the anal defecatory function and competence in UC patients undergoing TPC plus IPAA using high-resolution anorectal manometry (HR-ARM). PATIENTS: Patients undergoing TPC and IPAA were enrolled in the study and subjected to HR-ARM prior to and 6 months after surgery. The anal resting, squeeze and push pressures were recorded, together with the rectal sensation and the rectal balloon expulsion test. The number of bowel movements, symptoms/signs related to fecal incontinence, as well as the IBDQ-32 quality of life questionnaires were documented during both HR-ARM visits. RESULTS: A total of 20 consecutive UC patients were recruited in our study. The mean (SD) number of bowel movements before the TPC plus IPAA was 10.1 (2.8), while the same number after the pouch surgery was 7.7 (3.1) [ P  = 0.01]. Symptoms or signs of fecal incontinence were noted in one of our patients prior to the operation; however, none of our patients reported any such symptoms after the pouch surgery. The median (IQR) IBDQ-32 questionnaire scores before and after surgery were 121.5 (13.5) and 142.5 (16.0) respectively. At the same time, the anorectal function remained intact since both the anal resting and squeeze pressures were not significantly changed. CONCLUSION: UC patients subjected to TPC-IPAA exhibit improved bowel movements and a normal anal defecatory function and competence post-surgery.

Determinants of Dissatisfaction After Laparoscopic Cure of Vaginal and/or Rectal Prolapse using Mesh: a Comprehensive Retrospective Cohort Study.

INTRODUCTION AND HYPOTHESIS: The primary objective is to identify determinants of dissatisfaction after surgical treatment of vaginal prolapse ± rectal prolapse, using laparoscopic mesh sacrohysteropexy (LSH) or sacrocolpopexy (LSC) ± ventral mesh rectopexy (VMR). The secondary objective is the evaluation of complications and objective/subjective recurrence rates. METHODS: The study performed was a single-surgeon retrospective review of prospectively collected data. LSH/LSC ± VMR were performed between July 2005 and September 2022. Primary investigated outcome was patients' satisfaction, assessed using the Patient Global Impression of Improvement (PGI-I) score and the bother visual analog scale (VAS) obtained postoperatively (at a 1-month interval and on a 6-month/yearly basis thereafter). We looked for a correlation between the level of satisfaction (as reflected by the VAS) and potential determinants. RESULTS: There were 355 patients with a mean age of 62 ±12 years. Nearly all the patients (94.3%) had a stage 3 or 4 prolapse according to the POP-Q classification. The mean postoperative bother VAS was 1.8, with only 12.7% of patients reporting a bother VAS score ≥ 3/10, indicating a dissatisfaction. PGI-I showed improvement in the vast majority of patients (96.4% scoring 1 to 3). Patients with anal incontinence preoperatively scored higher on the bother VAS postoperatively (r=0.175, p < 0.05). The use of a posterior arm mesh (for posterior vaginal prolapse) correlated with better satisfaction overall (r= -0.178, p = 0.001), whereas the performance of VMR was associated with a bothering sensation (r = 0.232, p < 0.001). A regression analysis confirmed the impact of posterior mesh and VMR on satisfaction levels, with odds of dissatisfaction being 2.18 higher when VMR was combined with LSH/LSC. CONCLUSIONS: Posterior mesh use improves patient satisfaction when the posterior compartment is affected. In patients with concomitant vaginal and rectal prolapse, combining VMR with anterior LSC/LSH appears to negatively impact patients' satisfaction. Preoperative anal incontinence was demonstrated to be a risk factor for postoperative dissatisfaction.

Irritable bowel syndrome worsens faecal incontinence after primary repair of major obstetric anal sphincter injuries.

AIM: Obstetric anal sphincter injuries (OASIS) occur in approximately 3%-6% of vaginal deliveries and are the leading risk factor for late-onset faecal incontinence, which is an underdiagnosed pathology. The aim of this work was to use a validated scoring system to quantify the effect of irritable bowel syndrome (IBS) on the severity of faecal incontinence symptoms after primary repair of major OASIS (Grade IIIb-IV). METHOD: A prospective cohort study was performed on all women who underwent primary repair of major OASIS over a 6-year period. They were assessed with ultrasonography within 12 weeks. Two control groups (who did not have OASIS) were women who underwent elective caesarean section and primigravid women. Questionnaires were sent at least 12 months after delivery, or at first consultation for primigravids, which generated the main outcome measures: Cleveland Clinic faecal incontinence severity scores and the presence of IBS based on Rome III criteria. RESULTS: There was a total of 211 patients included in the three groups and the mean follow-up time was 26 months after sphincter repair. Ultrasonographic sphincter defects were detected in 37% but did not affect the faecal incontinence score (p = 0.47), except in patients with IBS. Within each group, patients with IBS had significantly worse faecal incontinence than those without. Women with both OASIS and IBS had the most severe faecal incontinence scores. CONCLUSION: OASIS has a limited negative effect on faecal incontinence, independent of whether residual ultrasonographic sphincter defects are present. However, the presence of IBS has a significant compounding effect on faecal incontinence in OASIS patients. The effect of IBS on faecal incontinence is also notable in caesarean section patients and primigravids, suggesting that IBS is an independent risk-factor that should have its place in predelivery assessment and counselling.

Laparoscopic Versus Transanal IPAA for Ulcerative Colitis: A Patient-Centered Treatment Trade-Off Study.

BACKGROUND: Transanal IPAA is a relatively new technique aiming to reduce surgical invasiveness while providing better access to the pelvis in patients with ulcerative colitis. Currently, patients' preference for a surgical approach has never been investigated. OBJECTIVE: To observe patient preference between transanal and laparoscopic IPAA by measuring the potential risk, expressed in pouch function reduction, patients are willing to take to undergo transanal surgery. DESIGN: We conducted standardized interviews of patients using the threshold technique. SETTINGS: Patients from Mount Sinai Hospital in Toronto were included. PATIENTS: Fifty-two patients with ulcerative colitis participated in this study. INTERVENTION: Patients with ulcerative colitis, with or without previous pouch surgery, were submitted to standardized interviews using the threshold technique. MAIN OUTCOME MEASURES: We measured the absolute increase in bowel frequency, bowel urgency, and fecal incontinence that patients would accept if undergoing transanal IPAA. RESULTS: Thirty-two patients (mean age: 38.7 ± 15.3 years) with previous surgery and 20 patients (mean age: 39.5 ± 11.9 years) with no previous surgery participated in this study. Patients accepted an absolute increase of 2 bowel movements per day and 1 episode of fecal incontinence per month to undergo transanal IPAA. They also accepted 10 minutes of worsening bowel urgency (ie, decrease of 10 minutes in "holding time") for transanal surgery. Younger patients aged 21 to 29 years only accepted an absolute decrease of 5 minutes in "holding time" ( p = 0.02). LIMITATIONS: Biases inherent to study design. CONCLUSIONS: Patients were willing to accept a potential reduction in pouch function to receive the less invasive method of transanal IPAA. More studies evaluating long-term functional outcomes after transanal IPAA are required to help patients make educated surgical decisions. See Video Abstract. ANASTOMOSIS LAPAROSCPICA VERSUS TRANSANAL ILEALBOLSA ANAL PARA LA COLITIS ULCEROSA UN ESTUDIO DE COMPENSACIN DE TRATAMIENTO CENTRADO EN EL PACIENTE: ANTECEDENTES:La anastomosis anal transanal con reservorio ileal es una técnica relativamente nueva que tiene como objetivo reducir la invasividad quirúrgica y al mismo tiempo proporcionar un mejor acceso a la pelvis en pacientes con colitis ulcerosa. Actualmente, nunca se ha investigado la preferencia de los pacientes sobre el abordaje quirúrgico.OBJETIVO:Observar la preferencia de los pacientes entre la anastomosis ileoanal con reservorio transanal y laparoscópica midiendo el riesgo potencial, expresado en la reducción de la función del reservorio, que los pacientes están dispuestos a someterse a una cirugía transanal.DISEÑO:Realizamos entrevistas estandarizadas de pacientes utilizando la técnica del umbral.AJUSTES:Se incluyeron pacientes del Hospital Mount Sinai en Toronto.PACIENTES:Cincuenta y dos pacientes con colitis ulcerosa participaron en este estudio.INTERVENCIÓN(ES):Los pacientes con colitis ulcerosa, con o sin cirugía previa de reservorio fueron sometidos a entrevistas estandarizadas utilizando la técnica del umbral.MEDIDAS DE RESULTADO PRINCIPALES:Medimos el aumento absoluto en la frecuencia intestinal, la urgencia intestinal y la incontinencia fecal que los pacientes aceptarían si se sometieran a una anastomosis transanal con bolsa ileal.RESULTADOS:Treinta y dos pacientes (edad media: 38,7 ± 15,3) con cirugía previa y 20 pacientes (edad media: 39,5 ± 11,9) sin cirugía previa participaron en este estudio. Los pacientes aceptaron un aumento absoluto de 2 deposiciones por día y un episodio de incontinencia fecal por mes para someterse a una anastomosis transanal ileoanal con reservorio. También aceptaron 10 minutos de empeoramiento de la urgencia intestinal (es decir, disminución de 10 minutos del "tiempo de espera") para la cirugía transanal. Los pacientes más jóvenes de 21 a 29 años solo aceptaron una disminución absoluta de 5 minutos en el "tiempo de espera" ( P = 0,02).LIMITACIONES:Sesgos inherentes al diseño del estudio.CONCLUSIONES:Los pacientes estaban dispuestos a aceptar una reducción potencial en la función del reservorio para recibir el método menos invasivo de anastomosis transanal ileoanal con reservorio. Se requieren más estudios que evalúen los resultados funcionales a largo plazo después de la anastomosis transanal ileoanal con reservorio para ayudar a los pacientes a tomar decisiones quirúrgicas informadas. (Traducción-Yesenia Rojas-Khalil ).

UK survey of colorectal surgeons on the management of acute obstetric anal sphincter injuries.

AIM: The role of colorectal surgeons in the management of acute obstetric anal sphincter injury (OASI) is an ongoing debate. Their expertise in operating in the anorectal region lends itself to assisting in OASI repair. The aim of this study was to establish the current involvement and recommended management of acute OASI by colorectal surgeons. METHOD: An online survey of consultant colorectal surgeons was sent to members of the Pelvic Floor Society to assess current involvement in acute OASI management and repair. RESULTS: Forty completed surveys were collated and analysed. Sixty-five per cent of respondents had seen an acute OASI since being a consultant and 50% stated they were involved in the repair of OASI less than once per year. 37.5% felt that a de-functioning stoma was still necessary sometimes. Many agreed with current guidelines for OASI repair in terms of antibiotics, laxatives and follow-up. CONCLUSIONS: Colorectal surgeons have varied opinions on the management of OASI. We suggest that multidisciplinary training of obstetricians and colorectal surgeons could lead to more collaboration regarding the management of women with acute OASI.

Long-term outcome after SphinKeeper® surgery for treating fecal incontinence-who are good candidates?

PURPOSE: The efficacy of the novel SphinKeeper® procedure for the treatment of fecal incontinence (FI) is not yet well defined. This study aimed to assess long-term functional outcomes after SphinKeeper® surgery. METHODS: We included 32 patients with FI (28 female), who were operated at a tertiary referral center between August 2018 and September 2021. Functional outcome and quality of life were evaluated prospectively using validated questionnaires before and after surgery. Additionally, endoanal ultrasound and anal manometry were conducted prior and after SphinKeeper® implantation. Predictive parameters for treatment success were defined. RESULTS: The mean follow-up time was 22.62 ± 8.82 months. The St. Mark's incontinence score decreased significantly after surgery (median preoperative = 19 (IQR 17-22) versus median last follow-up = 12 (IQR 8-16), p = 0.001). Similarly, physical short-form health survey showed a significant improvement after SphinKeeper® implantation (p = 0.011). Patients with a higher degree of internal sphincter defect showed an improved objective therapy success (r = 0.633, p = 0.015) after SphinKeeper® operation, whereas the type and severity of FI had no impact on the functional outcome. Notably, a higher number of dislocated prostheses (r = 0.772, p = 0.015) showed a significant correlation with reduced improvement of incontinence. CONCLUSION: The SphinKeeper® procedure showed a significant long-term functional improvement in over half of the patients. Patients with a higher internal sphincter defect benefited most, whereas dislocation of the prostheses was associated with less favorable results.

Cutting seton for the treatment of cryptoglandular fistula-in-ano: a systematic review and meta-analysis.

BACKGROUND: The use of cutting seton (CS) for the management of cryptoglandular fistula-in-ano has remained controversial because of reports of fecal incontinence, postoperative pain, and extended healing time. The aim of this review was to provide the first synthesis of studies investigating the use of CS for the treatment of cryptoglandular fistula-in-ano. METHODS: MEDLINE, Embase, and CENTRAL were searched up to October 2022. Randomized controlled trials and observational studies comparing CS with alternative interventions were included, along with single-arm studies evaluating CS alone. The primary outcome was fistula-in-ano recurrence, and secondary outcomes included incontinence, healing time, proportion with complete healing, and postoperative pain. Inverse variance random-effects meta-analyses were used to pool effect estimates. RESULTS: After screening 661 citations, 29 studies were included. Overall, 1513 patients undergoing CS (18.8% female, mean age: 43.1 years) were included. Patients with CS had a 6% (95% CI: 3-12%) risk of recurrence and a 16% (95% CI: 5-38%) risk of incontinence at 6 months. CS patients had an average healing time of 14.6 weeks (95% CI: 10-19 weeks) with 73% (95% CI: 48-89%) of patients achieving complete healing at 6 months postoperatively. There was no difference in recurrence between CS and fistulotomy, advancement flap, two-stage seton fistulotomy, or draining seton. CONCLUSIONS: Overall, this analysis shows that CS has comparable recurrence and incontinence rates to other modalities. However, this may be at the expense of more postoperative pain and extended healing time. Further comparative studies between CS and other modalities are warranted.

[Current status and prospects of non-surgical treatment for fecal incontinence].

Fecal incontinence is a refractory disease in colorectal surgery. The main clinical manifestation is that patients cannot control the discharge of gas, solid or liquid feces in the rectum autonomously. It is easy to bring shame to patients and seriously affect their physical and mental health. Reducing the frequency of fecal incontinence, restoring anal sphincter function, and improving patient quality of life are important goals for treating fecal incontinence. With the development of medical technology and the improvement of treatment plans for fecal incontinence, patients with fecal incontinence usually undergo conservative treatment first, and if conservative treatment is ineffective, surgery can be chosen. Non-surgical treatment methods commonly used in clinical practice include biofeedback therapy, magnetic stimulation therapy, pelvic floor muscle training, anal sphincter training, Kegel training, and other rehabilitation treatments. This article discusses the non-surgical treatment methods for fecal incontinence, hoping to provide a choice for clinical treatment of fecal incontinence.

[The occurrence, precaution and treatment strategies of postoperative fecal incontinence in rectal and anal diseases].

In the surgical treatment of hemorrhoids, rectal prolapse, rectal cancer, anal fissures, or anal fistulas, inadvertent damage to the nerves or muscles responsible for bowel control may potentially lead to varying degrees of fecal incontinence (FI). Surgeons need to conduct preoperative assessments based on the patient's individual condition to select an appropriate surgical plan, aiming to minimize the incidence of postoperative FI and improve the patient's postoperative quality of life as much as possible while effectively treating the disease. Additionally, the proficiency of the surgeon's skills, appropriate preoperative dietary adjustments for the patient, regular bowel habits, and exercises targeting the pelvic floor muscles all contribute to reducing the incidence of postoperative FI in patients. For patients who have already developed FI after surgery, on the basis of suitable diet, regular bowel habits, and medication, clinical practitioners can adopt such methods as biofeedback, pelvic floor muscle exercise, sacral nerve stimulation, percutaneous tibial nerve stimulation, acupuncture, injectable bulking agents, anal or vaginal inserts, transanal irrigation, surgical interventions, psychological support, etc., to individualized treatment for patients' conditions. This article, combining the literature, summarizes the current status of common diseases that may lead to postoperative FI. It elaborates on strategies for the prevention and treatment of postoperative FI, aiming to serve as a reference for peers in the field.

[Functional-neurosurgical treatment options for functional pelvic floor disorders : Value of sacral neuromodulation]. / Funktionell-neurochirurgische Therapieoptionen bei Funktionsstörungen des Beckenbodens : Stellenwert der sakralen Neuromodulation.

BACKGROUND: Sacral neuromodulation is an established minimally invasive therapy indicated for the treatment of functional pelvic floor disorders. While it received its original US Food and Drug Administration (FDA) approval for the treatment of overactive bladder symptoms, it is now regarded as a therapeutic option to treat both urinary/fecal incontinence and retention. In addition, it has proven to be a valuable tool in the treatment of chronic pelvic pain, and preliminary results indicate a potential to elicit improvements in sexual functioning. OBJECTIVE: This article serves to provide a summary of the therapy and its applications. METHOD: Selective literature review. RESULTS: Sacral neuromodulation implants allow for the controlled shifting of the autonomic control of bladder and rectum towards an inhibition or facilitation of voiding, dependent on the patient's needs and under the patient's control. At the same time and depending on the applied stimulation, the implants can interfere with the nerve's conduction of pain signals. This makes them a therapeutic option for pelvic pain that fails to respond to conventional treatment. Finally, there have been first reports suggesting improvements in sexual dysfunction under sacral neuromodulation, thus, potentially opening up a new line of therapy for those disorders. DISCUSSION: Sacral neuromodulation is a flexible and efficient form of therapy for functional disorders of the pelvic floor. Specifically, the same intervention can treat seemingly contradictory disorders such as urinary/fecal incontinence and retention as well as chronic pain.

Simulation of artificial anal sphincter motion and interaction with intestinal environment using SOFA.

BACKGROUND: Artificial anal sphincter is an implantable medical device for treating fecal incontinence. Reasonable simulation facilitates the advancement of research and reduces experiments on biological tissue. However, the device's clamping motion and sensor interaction with the intestine in the simulation still require further exploration. This article presents a simulation of the artificial anal sphincter's clamping and sensing and its interaction with the intestinal environment using the Simulation Open Framework Architecture (SOFA). METHODS: Firstly, the proposed simulation algorithm and its principles in SOFA are analyzed. Secondly, the clamping motion and sensor system of the artificial anal sphincter are simulated. Thirdly, a finite element model of intestine is established based on the properties of intestinal soft tissue. Finally, the in vitro experiments are performed. RESULTS: The simulation results indicate that the sensor system of the artificial anal sphincter has good sensing performance during the clamping motion and fecal accumulation process. Experiments have shown that optimal sensory capabilities can be achieved as the posture of the artificial anal sphincter with a roll angle between 20° and 40°. The comparison demonstrates a mean absolute error of 10%-20% between simulation and in vitro experimental results for sensor forces, which verifies the effectiveness of the simulation. CONCLUSION: The proposed novel simulation achieves a more comprehensive interaction between the artificial anal sphincter motion and intestinal environment. This study may provide more effective simulation data for guidance in improving the performance of sensor perception of artificial anal sphincter for further research.

Surgical treatment trends and outcomes for anal fistula: fistulotomy is still accurate and safe. Results from a nationwide observational study.

PURPOSE: The aim of the present study was to analyse current surgical treatment preferences for anal fistula (AF) and its subtypes and nationwide results in terms of success and complications. METHODS: A retrospective multicentre observational cohort study was conducted. The study period was 1 year (2019), with a follow-up period of at least 1 year. A descriptive analysis of patient characteristics and trends regarding technical options was performed. Univariate and multivariate Cox regression models were used to analyse factors associated with healing and faecal incontinence (FI). RESULTS: Fifty-one hospitals were involved, providing data on 1628 patients with AF. At a median follow-up of 18.3 (9.9-28.3) months, 1231 (75.9%) patients achieved healing, while 390 (24.1%) did not; failure was catalogued as persistence in 279 (17.2.0%) patients and as recurrence in 111 (6.8%). On multivariate analysis, factors associated with healing were fistulotomy (OR 5.5; 95% CI 3.8-7.9; p < 0.001), simple fistula (OR 2.1; 95% CI 1.5-2.8; p < 0.001), single tract (HR 1.9; 95% CI 1.3-2.8; p < 0.001) and number of preparatory surgeries (none vs. 3; HR 1.8; 95% CI 1.2-2.8; p = 0.006). Regarding de novo FI, in the multivariate analysis previous anal surgery (OR 1.5, 95% CI 1.0-2.4, p = 0.037), age (OR 1.02, 95% CI 1.00-1.04, p = 0.002) and being female (OR 1.7, 95% CI 1.1-2.5, p = 0.008) were statistically related. CONCLUSIONS: Anal fistulotomy is the most used procedure for AF, especially for simple AF, with a favourable overall balance between healing and continence impairment. Sphincter-sparing or minimally invasive sphincter-sparing techniques resulted in lower rates of healing. In spite of their intended sphincter-sparing design, a certain degree of FI was observed for several of these techniques.

Efficacy of different surgical treatments for management of anal fistula: a network meta-analysis.

PURPOSE: Currently, the anal fistula treatment which optimises healing and preserves bowel continence remains unclear. The aim of our study was to compare the relative efficacy of different surgical treatments for AF through a network meta-analysis. METHODS: Systematic searches of MEDLINE, EMBASE and CENTRAL databases up to October 2022 identified randomised controlled trials (RCTs) comparing surgical treatments for anal fistulae. Fistulae were classified as simple (inter-sphincteric or low trans-sphincteric fistulae crossing less than 30% of the external anal sphincter (EAS)) and complex (high trans-sphincteric fistulae involving more than 30% of the EAS). Treatments evaluated in only one trial were excluded from the primary analyses to minimise bias. The primary outcomes were rates of success in achieving AF healing and bowel incontinence. RESULTS: Fifty-two RCTs were included. Of the 14 treatments considered, there were no significant differences regarding short-term (6 months or less postoperatively) and long-term (more than 6 months postoperatively) success rates between any of the treatments in patients with both simple and complex anal fistula. Ligation of the inter-sphincteric fistula tract (LIFT) ranked best for minimising bowel incontinence in simple (99.1% of comparisons; 3 trials, n = 70 patients) and complex anal fistula (86.2% of comparisons; 3 trials, n = 102 patients). CONCLUSIONS: There is insufficient evidence in existing RCTs to recommend one treatment over another regarding their short and long-term efficacy in successfully facilitating healing of both simple and complex anal fistulae. However, LIFT appears to be associated with the least impairment of bowel continence, irrespective of AF classification.

Evaluating the risk factors for the development of benign disorders of defaecation: a surgical perspective.

PURPOSE: There remains uncertainty as to which risk factors are important for the development of defaecatory problems as a result of heterogeneity of published evidence. Understanding the impact of risk factors may be important in selecting targets for disease prevention or reversal. The aim of this study was to identify and evaluate risk factors for faecal incontinence and chronic constipation. METHODS: Risk factors for chronic constipation and faecal incontinence were long-listed from scientific literature, then anonymously evaluated (by 50 predominantly colorectal surgical experts from the UK Pelvic Floor Society) using a Delphi technique. Each risk factor was rated as independent, a co-factor, or not a risk factor. Independent risk factors were rated between 1 (not important) and 10 (critically important) with mean (± standard deviation) calculated. RESULTS: Thirty-eight risk factors for chronic constipation were evaluated. Eighteen were classed as independent and 16 as co-factors. Opioid analgesia (7.87 ± 2.05), eating disorders (7.80 ± 1.72), and history of abuse (7.70 ± 1.89) were scored as most important independent risk factors. Female sex (6.60 ± 2.02) was considered an independent risk factor but increasing age was rated a co-factor. Thirty-three risk factors for faecal incontinence were evaluated. Twenty were classed as independent and eight as co-factors. Third- or fourth-degree tear (8.88 ± 1.57), instrumental delivery (8.47 ± 1.58), and grand multiparity (8.00 ± 1.63) were rated most important. Increasing age (7.41 ± 2.14) and female sex (7.58 ± 2.05) were both considered independent risk factors. CONCLUSIONS: Several risk factors for chronic constipation and faecal incontinence were selected by Delphi approach. These factors will feed forward into Bayesian models of disease prediction that combine data and expert knowledge.