Internal anal sphincter

The internal anal sphincter, the smooth muscle component of the anal sphincter complex, has an ambiguous role in maintaining anal continence. Despite its significant contribution to resting anal canal pressures, even total division of the internal anal sphincter in surgery for anal fistulas may fail to compromise continence in otherwise healthy subjects. However, recently reported abnormalities of the innervation and reflex response of the internal anal sphincter in patients with fecal incontinence indicate its significance in maintaining continence. The advent of sphincter-saving surgery and restorative proctocolectomy has re-emphasized the major contribution of the internal anal sphincter to resting pressure and its significance in preventing fecal leakage. The variable effect of rectal excision on rectoanal inhibitory reflex has led to a reappraisal of the significance of this reflex in discrimination of rectal contents and its impact on anal continence. Electromyographic, manometric, and ultrasonographic evaluation of the internal anal sphincter has provided new insights into its pathophysiology. This article reviews advances in our understanding of internal anal sphincter physiology in health and disease.     

Vaginal Delivery After Ileal Pouch-Anal Anastomosis: A Word of Caution

PURPOSE This study was designed to evaluate the impact of childbirth on anal sphincter integrity and function, functional outcome, and quality of life in females with restorative proctocolectomy and ileal pouch-anal anastomosis.METHODS The patients who had at least one live birth after ileal pouch-anal anastomosis were asked to return for a comprehensive assessment. They were asked to complete the following questionnaires: the Short Form-36, Cleveland Global Quality of Life scale, American Society of Colorectal Surgeons fecal incontinence severity index, and time trade-off method. Additionally, anal sphincter integrity (endosonography) and manometric pressures were measured by a medical physician blinded to the delivery technique. Anal sphincter physiology also was evaluated with electromyography and pudendal nerve function by nerve terminal motor latency technique.RESULTS Of 110 eligible females who had at least one live birth after ileal pouch-anal anastomosis, 57 participated in the study by returning for clinical evaluation to the clinic and 25 others by returning the quality of life and functional outcome questionnaires. Patients were classified into two groups: patients who had only cesarean section delivery after ileal pouch-anal anastomosis (n = 62) and patients who had at least one vaginal delivery after ileal pouch-anal anastomosis (n = 20). The mean follow-up from the date of the most recent delivery was 4.9 years. The vaginal delivery group had significantly higher incidence of an anterior sphincter defect by anal endosonography (50 percent) vs. cesarean section delivery group (13 percent; P = 0.012). The mean squeeze anal pressure was significantly higher in the patients who had only cesarean section delivery (150 mmHg) after restorative proctocolectomy than patients who had at least one vaginal delivery (120 mmHg) after restorative proctocolectomy (P = 0.049). Quality of life evaluated by time trade-off method also was significantly better in the cesarean section delivery group (1) vs. vaginal delivery group (0.9; P < 0.001).CONCLUSIONS The risk of the sphincter injury and quality of life measured by time trade-off method are significantly worse after vaginal delivery compared with cesarean section in patients with ileal pouch-anal anastomosis. In the short-term, this does not seem to substantially influence pouch function or quality of life; however, the long-term effects remain unknown, thus obstetric concern may not be the only factor dictating the type of delivery in this group of patients. A planned cesarean section may eliminate these potential and factual concerns in ileal pouch-anal anastomosis patients.Podium presentation at the meeting of The American Society of Colon and Rectal Surgeons, Dallas, Texas, May 8 to 13, 2004.     

Chronic sacral spinal nerve stimulation for fecal incontinence: Long-term results with foramen and cuff electrodes

PURPOSE: Sacral spinal nerve stimulation is a new therapeutic approach for patients with severe fecal incontinence owing to functional deficits of the external anal sphincter. It aims to use the morphologically intact anatomy to recruit residual function. This study evaluates the long-term results of the first patients treated with this novel approach applying two techniques of sacral spinal nerve stimulator implantation. METHODS: Six patients underwent either of two techniques for electrode placement: one closed (electrodes placed through the sacral foramen) and one open (cuff electrodes placed after sacral laminectomy). Follow-up evaluation of their continence status ranged from 5 to 66 months. RESULTS: Incontinence improved in all patients. The percentage of incontinent bowel movements decreased during chronic stimulation from a mean of 40.2 percent to 2.8 percent, and the Wexner score decreased from a mean of 17 to 2. The function of the striated anal sphincter improved during chronic stimulation: maximum squeeze pressure increased from a mean of 48.5 mmHg to 92.7 mmHg, and median squeeze pressure increased from a mean of 37.3 mmHg to 72.5 mmHg. No complications were encountered perioperatively or postoperatively. Two devices had to be removed because of intractable pain, in one patient at the site of the electrode after five months and in the other at the site of the impulse generator after 45 months. CONCLUSION: Long-term sacral spinal nerve stimulation persistently improves continence and increases striated anal sphincter function in patients with fecal incontinence owing to functional deficits, but in whom the striated anal sphincter is morphologically intact. Two different operative approaches can be applied effectively.Supported by grants from Bayerischen Chirurgen e.V., Munich, Germany; Wilhelm Sander Stiftung, Neustadt, Germany; and Bakken Research Center, Medtronic, Maastricht, the Netherlands.A preliminary report of this study was presented as a poster at the meeting of The American Society of Colon and Rectal Surgeons, San Antonio, Texas, May 2 to 7, 1998.     

Prevalence of pudendal neuropathy in fecal incontinence

PURPOSE: A prospective study was made of the prevalence and associations of pudendal neuropathy in 96 patients with fecal incontinence (72 females and 24 males). METHODS: Clinical exploration, perineal level measurement, anorectal manometry, and electrophysiologic evaluations (pudendal nerve terminal motor latency (PNTML) and external sphincter fiber density (FD)) were performed. RESULTS: Pudendal neuropathy (defined as PNTML>2.2 ms or FD>1.65) was found in 67 patients (69.8 percent) and was more common in females (75 percent) than in males (50 percent;P = 0.05). Pudendal neuropathy was also more frequent in patients with pathologic perineal descent (85 percent vs. 55 percent;P <0.01) or exhibiting risk factors such as difficult labor or excessive defecatory straining (P <0.01). Perineal level at straining correlated inversely with both PNTML and FD (P <0.01). Manometric findings suggested greater external anal sphincter damage in patients with pudendal neuropathy than in those suffering fecal incontinence but no neuropathy (P <0.05). Pressure caused by the striated anal sphincter was also inversely correlated to PNTML. Pudendal neuropathy was encountered in 37 of 63 (58.7 percent) patients with sphincter injury vs.in 31 of 33 (93.9 percent) patients with idiopathic fecal incontinence (P < 0.01). CONCLUSIONS: Pudendal neuropathy is an etiologic or associated factor often present in patients with fecal incontinence. In this sense, clinical, perineometric, and manometric findings correlate with pudendal neuropathy, though such explorations do not suffice to detect it.Read at the meeting of The American Society of Colon and Rectal Surgeons, Orlando, Florida, May 8 to 13, 1994.     

Sacral nerve stimulation for treatment of fecal incontinence in a patient with muscular dystrophy: report of a case

Fecal incontinence is a common condition that causes major impairment of social life. Sacral nerve stimulation is a promising treatment in idiopathic fecal incontinence when conventional treatments have failed. However, new indications for sacral nerve stimulation are emerging. The present case shows that sacral nerve stimulation for treatment of fecal incontinence may be justified in other diseases in which fecal incontinence is a major problem.     

Long-term results of suture rectopexy in patients with fecal incontinence associated with incomplete rectal prolapse

Suture rectopexy is the recommended therapy for complete rectal prolapse that is associated with fecal incontinence. It has been suggested that correction of an incomplete rectal prolapse is also worthwhile for patients with fecal incontinence. PURPOSE: Aims of this study were 1) to evaluate the clinical outcome of suture rectopexy in a consecutive series of patients with incomplete rectal prolapse associated with fecal incontinence, and 2) to compare these results with those obtained from patients with complete rectal prolapse. METHODS: Between 1979 and 1994, suture rectopexy was performed in 13 incontinent patients (3 males; median age, 65 (range, 45–77) years) with incomplete rectal prolapse (Group I) and in 24 incontinent patients (21 females; median age, 71 (range, 24–86) years) with complete rectal prolapse (Group II). RESULTS: After a median follow-up of 67 months, continence was restored in 5 of 13 (38 percent) patients with incomplete rectal prolapse and in 16 of 24 (67 percent) patients with complete rectal prolapse. In both groups, all male patients became continent. CONCLUSIONS: For the majority of incontinent patients with incomplete rectal prolapse, a suture rectopexy is not beneficial. The clinical outcome of this procedure is only good in incontinent patients with complete rectal prolapse. Based on these data, it is questionable whether incomplete rectal prolapse plays a causative role in fecal incontinence.Read at the meeting of the International Society of University Colon and Rectal Surgeons, Lisboa, Portugal, April 14 to 18, 1996.No reprints are available.     

Recurrent rectal prolapse

PURPOSE: The aim of this study was to assess the clinical and functional outcome of surgery for recurrent rectal prolapse and compare it with the outcome of patients who underwent primary operation for rectal prolapse. METHODS: All patients who underwent surgery for rectal prolapse were evaluated for age, gender, procedure, anorectal manometry and electromyography findings, and morbidity. The results for patients who underwent surgery for recurrent rectal prolapse were compared with a group of patients matched for age, gender, surgeon, and procedure who underwent primary operations for rectal prolapse. RESULTS: A total of 115 patients underwent surgery for rectal prolapse. Twenty-seven patients, 10 initially operated on at this institution and 17 operated on elsewhere, underwent surgery for recurrent rectal prolapse. These 27 patients were compared with 27 patients with primary rectal prolapse operated on in our department. In the recurrent rectal prolapse group, prior surgery included rectopexy in 7 patients, Delorme's procedure in 7 patients, perineal rectosigmoidectomy in 7 patients, anal encirclement procedure in 4 patients, and resection rectopexy in 2 patients. Operations performed for recurrence were perineal rectosigmoidectomy in 14 patients, resection rectopexy in 8 patients, rectopexy in 2 patients, pelvic floor repair in 2 patients, and Delorme's procedure in 1 patient. There were no statistically significant differences between the groups in preoperative incontinence score (recurrent rectal prolapse, 13.6±7.8vs. rectal prolapse, 12.7±7.2; range, 0–20) or manometric or electromyography findings, and there were no significant differences in mortality (0vs. 3.7 percent), mean hospital stay (5.4±2.5vs. 6.9±2.8 days), anastomotic complications (anastomotic stricture (0vs. 7.4 percent), anastomotic leak (3.7vs. 3.7 percent) and wound infection (3.7vs. 0 percent)), postoperative incontinence score (2.8±4.8vs. 1.5±2.7), or recurrence rate (14.8vs. 11.1 percent) between the two groups at a mean follow-up of 23.9 (range, 6–68) and 22 (range, 5–55) months, respectively. The overall success rate for recurrent rectal prolapse was 85.2 percent. CONCLUSION: The outcome of surgery for rectal prolapse is similar in cases of primary or recurrent prolapse. The same surgical options are valid in both scenarios.Funded in part by a generous grant from the Eleanor Naylor Dana Charitable Trust Fund and the Caporella Family.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, June 22 to 26, 1997.     

Fecal markers in the management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by periods of symptomatic remission and relapse. Diagnosis and assessment of IBD are based on clinical evaluation, serum parameters, radiology, and endoscopy. Fecal markers have emerged as new diagnostic tools to detect and monitor intestinal inflammation. Fecal calprotectin (FC) and lactoferrin (FL) were identified decades ago as potentially revolutionary markers for IBD. Following these discoveries numerous additional markers, including S100A12, M2-PK, metalloproteinases, hemoglobin, myeloperoxidase, lysozyme, polymorphonuclear elastase, neopterin, and nitric oxide, have also been suggested as novel markers of IBD. But only FC and FL are used for the management of clinical IBD patients. The objective of this review is to introduce the clinical applications of fecal markers in the diagnosis, monitoring and prediction of outcomes of inflammatory bowel disease.     

粪菌移植在炎症性肠病中的治疗进展

炎症性肠病(IBD)是肠道慢性、复发性自身免疫性疾病,是由遗传易感的宿主对肠道菌群异常的免疫反应所致。近年来,肠道菌群与IBD患病的关系倍受关注。粪菌移植(FMT)是将健康人肠道菌群移植至病人的胃肠道内,重建具有正常功能的肠道菌群。许多研究结果表明,FMT在IBD治疗中有效。以下就国内外FMT中心发表的FMT在IBD病人中治疗进展作一综述。     

High fecal calprotectin levels are associated with SARS-CoV-2 intestinal shedding in COVID-19 patients: A proof-of-concept study

BACKGROUNDOne third of coronavirus disease 2019 (COVID-19) patients have gastrointestinal symptoms. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA has been detected in stool samples of approximately 50% of COVID-19 individuals. Fecal calprotectin is a marker of gastrointestinal inflammation in the general population.AIMTo investigate if fecal calprotectin correlates with SARS-CoV-2 intestinal shedding in COVID-19 patients with pneumonia.METHODSPatients with SARS-CoV-2 pneumonia admitted to the Infectious Disease Unit (University Hospital of Trieste, Italy) from September to November 2020 were consecutively enrolled in the study. Fecal samples were collected and analyzed for quantification of fecal calprotectin (normal value < 50 mg/kg) and SARS-CoV-2 RNA presence by polymerase chain reaction (PCR). Inter-group differences were determined between patients with and without diarrhea and patients with and without detection of fecal SARS-CoV-2.RESULTSWe enrolled 51 adults (40 males) with SARS-CoV-2 pneumonia. Ten patients (20%) presented with diarrhea. Real-time-PCR of SARS-CoV-2 in stools was positive in 39 patients (76%), in all patients with diarrhea (100%) and in more than two thirds (29/41, 71%) of patients without diarrhea. Obesity was one of the most common comorbidities (13 patients, 25%); all obese patients (100%) (P = 0.021) tested positive for fecal SARS-CoV-2. Median fecal calprotectin levels were 60 mg/kg [interquartile range (IQR) 21; 108]; higher fecal calprotectin levels were found in the group with SARS-CoV-2 in stools (74 mg/kg, IQR 29; 132.5) compared to the group without SARS-CoV-2 (39 mg/kg, IQR 14; 71) (P < 0.001).CONCLUSIONHigh fecal calprotectin levels among COVID-19 patients correlate with SARS-CoV-2 detection in stools supporting the hypothesis that this virus can lead to bowel inflammation and potentially to the ‘leaky gut’ syndrome.