Study of the role of the transverse perineal muscles during rectal filling

Background The function of perineal muscles at defecation is poorly addressed in the literature. We investigated the hypothesis that rectal distension effects reflex contraction of four perineal muscles.Patient/methods After rectal balloon distension with carbon dioxide in increments of 20 ml, the responses of electromyographic (EMG) activity of superficial (STPM) and deep (DTPM) transverse perineal muscles as well as the rectal pressure were recorded in 22 healthy volunteers (14 men, age 37.2±6.3 years). Responses were registered again after individual anesthetization of rectum and transverse perineal muscles. Tests were repeated using saline instead of lidocaine.Results/findings Rectal balloon distension in big volumes effected increase of the transverse perineal muscles’ EMG activity and rectal pressure. The more the rectum was distended, the more the rectal pressure and EMG activity of the transverse perineal muscles were increased. The latency showed a gradual decrease upon incremental rectal distension increase. Transverse perineal muscles did not respond to rectal distension after the rectum and perineal muscles had been individually anesthetized, but it responded to saline administration. Response of the muscles was similar in both sides.Interpretation/conclusion Increase of rectal pressure increases EMG activity of transverse perineal muscles. This action seems mediated through a reflex which we call ‘recto-perineal reflex’. Contraction of transverse perineal muscles at defecation presumably supports the perineal floor. It also protects transverse perineal muscles against straining-produced high pressure that is transmitted through the recto-vaginal/-vesical cul de sac to the perineum which may sag down and share in genesis of perineocele, enterocele, or sigmoidocele.     

Surgical workshop: a new modification with the use of a seton in treating anal fistula

With increased usage of advancement flaps for treating complicated anal fistulae, the seton technique is still utilized. Various methods have been described to advance the seton through the external anal sphincter muscle. Herein, we describe a simple new technique to facilitate tightening of the seton in the office setting. Received: 30 March 2000 / Accepted: 10 June 2000     

Strength-Duration Testing of the External Anal Sphincter in Females with Anorectal Dysfunction

PURPOSE: The strength-duration test has been suggested as a means of assessing external anal sphincter function. This study was designed to investigate this claim by comparing the strength-duration test with established measures of external anal sphincter function. METHODS: Forty-nine females undergoing diagnostic anorectal testing (manometry, rectal sensation, electromyogram, pudendal nerve terminal motor latency, and endoanal ultrasound) also had the strength-duration test performed (which was repeated for each patient after a short rest period). RESULTS: The strength-duration test was repeatable. Statistically significant correlations were found between this test at pulse durations of 3 ms, 1 ms, and 0.3 ms with electromyographic activity of the external anal sphincter and with pressure in the anal canal during voluntary contraction. Significant correlations were found for durations of 100 ms, 30 ms, 10 ms, and 3 ms with the pudendal nerve terminal motor latency on the right and for the 3 ms and 0.3 ms durations with latency on the left. There were no correlations between the strength-duration test and resting pressure in the anal canal. CONCLUSION: The strength-duration test significantly correlates with the established measures of external anal sphincter function and its innervation. Therefore, this simple test appears to provide a simple measure of external anal sphincter denervation.     

Closure Mechanism of the Anal Canal in Women: Assessed by Three-Dimensional Ultrasound Imaging

Purpose  To describe the functional correlates of anal canal anatomy using 3 dimensional ultrasound imaging. Methods  Ten nulliparous women were studied by using a 10-cm bag of 20-mm diameter. The bag was placed along the anal canal and inflated with 20 to 45 ml water, in 5-ml increments. At each volume, a three-dimensional ultrasound volume of the anal canal was obtained while the subjects were at rest and squeeze. The ultrasound images were analyzed to determine the relationship between the bag cross-sectional area and bag pressure. Results  At low distension volumes, the bag is shaped like an “hourglass.” The flared ends of the funnels correspond with the proximal and distal margins of the puborectalis muscle and external anal sphincter respectively. With increasing bag volumes, the length of completely closed segment of anal canal decreased. The last anal segment to open at rest was the one surrounded by all three structures. Anal contraction resulted in reduction of the anal canal cross-sectional area; the least compliant part of the anal canal was the one surrounded by external anal sphincter. Conclusion  The internal anal sphincter, external anal sphincter, and puborectalis muscle are all involved in the anal canal closure function. During contraction, the external anal sphincter is the strongest component of anal canal closure mechanism. Supported by an NIH grant-RO-1, grant DK60733.     

消痔灵注射加外括约肌折叠术治疗老年性直肠脱垂的疗效分析

目的探讨老年性直肠脱垂的有效治疗方式。方法采用消痔灵注射加外括约肌折叠术治疗Ⅱ～Ⅲ度老年性直肠脱垂35例,观察患者的疗效。结果35例均近期全部治愈,有效率100％,治愈率94％,除1例糖尿病患者肛缘缝合处感染,经拆线后充分引流后治愈。结论应用直肠黏膜及肛周间隙消痔灵注射加外括约肌折叠术治疗老年性直肠脱垂,具有疗效高、疗程短、创伤小、痛苦小的优点。     

Voluntary relaxation of the external anal sphincter

In this study five volunteers with special training in anal sphincter exercise (Scandinavian Yoga School) managed voluntarily to reduce anal pressure. The mean reduction of anal pressure was 20 mm Hg. In one of the subjects, this was shown by manometry during low spinal anesthesia and electromyography to be caused by relaxation of the external anal sphincter.     

Sacral Nerve Stimulation for Fecal Incontinence: External Anal Sphincter Defect <Emphasis Type="Italic">vs</Emphasis>. 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°:defect 90°–120° = 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° of circumference. ^†Deceased.     

Sacral Nerve Stimulation Can Be Successful in Patients With Ultrasound Evidence of External Anal Sphincter Disruption

PURPOSE This study was designed to determine whether patients with fecal incontinence and endoanal ultrasound evidence of anal sphincter disruption may be successfully treated by sacral nerve stimulation.METHODS Five consecutive females with incontinence to solids and endoanal ultrasound evidence of anal sphincter disruption were treated by a two-week trial of sacral nerve stimulation. If successful, patients then proceeded to permanent sacral nerve stimulation implantation.RESULTS Five patients, aged 34 to 56 years, were treated by temporary sacral nerve stimulation. Four had symptoms starting after childbirth. Two had previously had an anterior sphincter repair. After a two-week trial, three females reported full continence and an improvement in all aspects of their Rockwood fecal incontinence quality of life scores. These three females underwent permanent sacral nerve stimulation implantation. The remaining two patients reported no improvement and underwent dynamic graciloplasty or end colostomy respectively.CONCLUSIONS Sacral nerve stimulation may successfully restore bowel continence in some patients with endoanal ultrasound evidence of a defect in their external anal sphincter.     

A comparison of dynamic transperineal ultrasound (DTP-US) with dynamic evacuation proctography (DEP) in the diagnosis of cul de sac hernia (enterocele) in patients with evacuatory dysfunction

Background/Aims Cul-de-sac hernias (enterocele and peritoneocele) are difficult to diagnose in patients presenting with primary evacuatory difficulty. Failure to recognize their presence in patients undergoing surgery may lead to poor functional outcome. Accurate diagnosis requires specialized investigation including dynamic evacuation proctography (DEP) or dynamic magnetic resonance (MR) imaging. Recently, dynamic transperineal ultrasonography (DTP-US) has been used for this purpose. This study compares DEP with DTP-US for the diagnosis of cul-de-sac hernias in those patients presenting with evacuatory dysfunction. Materials and methods Sixty-two female patients with chronically obstructed defecation underwent blinded clinical, DEP, and DTP-US assessment to define the accuracy of diagnosis of cul-de-sac hernias. Results Both the DEP and the DTP-US techniques show concordance for the diagnosis of cul-de-sac hernias in an unselected patient cohort. Patients in both groups have the same duration of constipation with a greater likelihood of prior hysterectomy in those with cul-de-sac hernias. The diagnosis was established separately by DEP in 88% and in 82% of the cases by DTP-US. Transperineal sonography is discordant with DEP in 45% of cases once the diagnosis of cul-de-sac hernia is made, over the contents of the hernia and over the degree of transvaginal enterocele descent, where DTP-US tends to upgrade enterocele severity. Both techniques confirm the high incidence of concomitant pelvic floor compartment pathology. Conclusions Both methods have accuracy for the diagnosis of cul-de-sac hernias in those patients presenting with evacuatory difficulty. Transperineal sonography tends to more readily diagnose peritoneocele and to upgrade enterocele extent. As an office procedure, it is a valuable adjunct to the clinical examination in the diagnosis of cul-de-sac hernia.     

Atrophy and Defects Detection of the External Anal Sphincter: Comparison Between Three-Dimensional Anal Endosonography and Endoanal Magnetic Resonance Imaging

Purpose Using endoanal magnetic resonance imaging, atrophy of the external anal sphincter can be established. This aspect has not been thoroughly investigated using three-dimensional anal endosonography. The purpose of this study was to compare prospectively three-dimensional anal endosonography to magnetic resonance imaging in the detection of atrophy and defects of the external anal sphincter in patients with fecal incontinence. In addition, we compared both techniques for anal sphincter thickness and length measurements. Materials and Methods Patients with fecal incontinence underwent three-dimensional anal endosonography and magnetic resonance imaging. Images of both endoluminal techniques were evaluated for atrophy and defects of the external anal sphincter. External anal sphincter atrophy scoring with three-dimensional anal endosonography depended on the distinction of the external anal sphincter and its reflectivity. External anal sphincter atrophy scoring with magnetic resonance imaging depended on the amount of muscle and the presence of fat replacement. Atrophy score was defined as none, moderate, and severe. A defect was defined at anal endosonography by a hypoechogenic zone and at magnetic resonance imaging as a discontinuity of the sphincteric ring and/or scar tissue. Differences between three-dimensional anal endosonography and magnetic resonance imaging for the detection of external anal sphincter atrophy and defects were calculated. In addition, we compared external anal sphincter thickness and length measurements in three-dimensional anal endosonography and magnetic resonance imaging. Results Eighteen patients were included (median age, 58 years; range, 27–80; 15 women). Three-dimensional anal endosonography and magnetic resonance imaging did not significantly differ for the detection of external anal sphincter atrophy (P = 0.25) and defects (P = 0.38). Three-dimensional anal endosonography demonstrated atrophy in 16 patients, magnetic resonance imaging detected atrophy in 13 patients. Three-dimensional anal endosonography agreed with magnetic resonance imaging in 15 of 18 patients for the detection of external anal sphincter atrophy. Using the grading system, 8 of the 18 patients scored the same grade. Three-dimensional anal endosonography detected seven external anal sphincter defects and magnetic resonance imaging detected ten. Three-dimensional anal endosonography and magnetic resonance imaging agreed on the detection of external anal sphincter defects in 13 of 18 patients. Comparison between three-dimensional anal endosonography and magnetic resonance imaging for sphincter thickness and length measurements showed no statistically significant concordance and had no correlation with external anal sphincter atrophy. Conclusion This is the first study that shows that three-dimensional anal endosonography can be used for detecting external anal sphincter atrophy. Both endoanal techniques are comparable in detecting atrophy and defects of the external anal sphincter, although there is a substantial difference in grading of external anal sphincter atrophy. Correlation between three-dimensional anal endosonography and magnetic resonance imaging for thickness and length measurements is poor. Inconsistency between the two methods needs to be evaluated further. Supported in part by grant No. 945-01-013 from the Netherlands Organization for Health Research and Development. Presented in part at the United European Gastroenterology Week, Prague, Czech Republic, September 25 to 29, 2004. Reprints are not available.     

Electrodiagnosis of the anorectum: a review of techniques and clinical applications

Abstract. Electrodiagnostic tests may be valuable in the assessment of patients with anorectal dysfunction and are complementary to imaging and manometry. While the latter delineate morphological and functional sphincter changes, respectively, electrodiagnostic methods document, help to localize and assess the severity and mechanism of neural injury. These data are important for the treatment of patients and for estimating their prognoses. Among electrodiagnostic tests, concentric needle electromyography of the external anal sphincter is the most important. It demonstrates muscle denervation, quantitatively estimates muscle reinnervation, estimates the level of motor neuron excitability and assesses several kinesiological parameters. In addition, measurement of the bulbocavernosus reflex is often useful, while pudendal somatosensory evoked potentials are sometimes useful. Use of single tests of sacral nervous system by workers less familiar with theoretical principles of clinical neurophysiology is discouraged. In patients with suspected neurogenic bowel disorders, comprehensive electrodiagnostic approach, performed by clinical neurophysiologists experienced in application of these tests to the sacral nervous system, should complement data obtained by other methods and giude patient management.Presented in part at the Meeting of the Mediterranean Society of Coloproctology, Otoec, Slovenia, September 2002.     

Anatomy of the anal sphincters

PURPOSE: A recent application of endosonography in the evaluation of anal sphincter morphology has led to controversy about the possibility of precisely assessing the diameter of external and internal anal sphincter muscles. On the other hand, magnetic resonance imaging (MRI) has been proposed to allow a more detailed view of the anatomy of the pelvic floor. However, both techniques have not yet been compared directly. METHODS: Eight healthy volunteers (age range, 25–40 years; 53, malefemale) participated. Anal ultrasound was performed using a 7.5-MHz rectal transducer which produced a transversal panorama display of 360, allowing an image perpendicular to the anal canal. Imaging of the diameter of the internal and external anal sphincter muscles was performed with the transducer placed in the midanal canal, and measurement was always performed by the same investigator in dorsal projection. MRI was performed using a 1.5 Tesla Magnetom (Siemens, Erlangen, Germany) to obtain sagittal and angled axial (perpendicular to the anal canal) planes for consecutive 3-mm slices which were evaluated by four independent raters. RESULTS: Muscle thickness of the sphincter muscles in dorsal projection was 1.96±0.61 mm for the internal sphincter and 6.35±1.07 mm for the external sphincter using ultrasound. It was 1.72±0.13 mm and 3.99±0.99 mm, respectively, using MRI. When both measures were compared, only the internal sphincter data correlated significantly (r=0.818,P=0.0023) between both measures. Sagittal resonance imaging of the anal canal did not allow for differentiation of both muscles at all. Differentiation among mucosa, submucosa, and internal anal sphincter is not possible with MRI but may well be performed with high-resolution ultrasound. CONCLUSION: Anal ultrasound carries the potential of becoming a routine clinical procedure for evaluation of the anal anatomy and morphology in defecation disorders, but current MRI assessment of the anal anatomy is elaborate, costly, and does not provide any further insights.Supported by Grant En 50/10 from the Deutsche Forschungs-gemeinschaft.Abstract published in Gastroenterology 1994;104:A577.     

A New Implantation Procedure of Artificial Sphincter for Anal Incontinence: The Transvaginal Approach

A destroyed or severely scarred anterior perineum predicts difficult healing and risk of perineal erosion and remains a contraindication for the implantation of an artificial anal sphincter via a perineal approach. This report describes the first implantations of an artificial anal sphincter via a transvaginal approach in female patients with anal incontinence. Between 2003 and 2005, the Acticon Neosphincter was implanted via a transvaginal approach in nine patients (average age, 43 (range, 25-73) years). These patients had severe fecal incontinence and failed previous therapies or were not amenable to lesser forms of therapy. A successful outcome was achieved in eight of nine patients (89 percent), and for these eight patients the artificial anal sphincter was activated. With a mean follow-up of 21.5 (range, 8-38) months, the mean Cleveland Clinic Score of incontinence decreased from 19 (range, 18-20) before the procedure to 8.6 (range, 2-14) at the last follow-up. None of the patients complained of dyspareunia; vaginal length was not a significant consideration, because this procedure does little to compromise this parameter. This approach is not without complications but its success rate is notable, especially when taking into account that these are patients not amenable to other therapies and only candidates to permanent colostomy.     

The identification of specialized pacemaking cells in the anal sphincters

Background and aims Interstitial cells of Cajal (ICC) are claimed to generate the electrical activity in the colon and stomach. As the external (EAS) and internal (IAS) anal sphincters exhibit resting electrical activity, we hypothesized the presence of ICC in these sphincters. This hypothesis was investigated in the current study.Patients/Methods Specimens from the EAS and IAS were taken from normal areas of the anorectum which had been surgically excised by abdominoperineal operation for rectal cancer of 28 patients (16 men, 12 women, mean age 42.2±4.8 years). The specimens were subjected to c-kit immunohistochemistry. Controls for the specificity of the antisera consisted of tissue incubation with normal rabbit serum substituted for the primary antiserum.Results/Findings Fusiform, c-kit positive, ICC-like cells were detected in the anal sphincters; they had dendritic processes. They were clearly distinguishable from the non-branching, c-kit negative smooth and striated muscle cells of the anal sphincters. The specimens contained also c-kit positive mast cells, but they had a rounded body with no dendritic processes. Immunoreactivity was absent in negative controls in which the primary antibody was omitted.Interpretation/Conclusion We have identified, for the first time, cells in EAS and IAS with morphological and immunological phenotypes similar to ICCs of the gut. These cells appear to be responsible for initiating the slow waves recorded from the anal sphincters and for controlling their activity. A deficiency or absence of these cells may affect the anal motile activity. Studies are needed to explore the role of these cells in anal motility disorders.     

Outcome of patients with an implanted artificial anal sphincter for severe faecal incontinence A single institution report

Implantation of an artificial sphincter is an alternative treatment for patients with severe faecal incontinence. This prospective study from one institution has evaluated the results from 13. Preoperative and postoperative incontinence scores, anal manometry, and quality of life were evaluated in 13 patients who had undergone implantation of an artificial sphincter over a 7-year period. Two patients were definitive failures. One developed acute total colitis after 5 years of satisfactory function, and a second had discomfort and demanded removal of an otherwise functioning device. After a median follow-up of 30 (range 5–76) months, 11 patients had an activated and functional device. These included 6 with a urinary AMS 800 and 5 with the newly designed anal ABS. The mean incontinence score decreased from 17 to 4, and quality of life improved markedly. Two of the 11 patients had undergone successful reimplantation, one following rupture of the cuff and the second following ulceration of the control pump through the labia. In no case was infection or erosion of the anal canal a cause of failure. While the cause of incontinence and age did not affect outcome, psychological reaction had a significant impact. The artificial anal sphincter may have a role to play in severe faecal incontinence. Accepted: 2 December 1997     

A Pilot Study of the Effects of Sildenafil on Stool Characteristics, Colon Transit, Anal Sphincter Function, and Rectal Sensation in Healthy Men

Nitric oxide is an important mediator of gut smooth muscle relaxation and visceral sensation. Sildenafil results in stimulation of the nitric oxide-cyclic GMP pathway. We sought to determine the effects of daily sildenafil administration on colorectal function. Over a 4-week period, sildenafil was administered during weeks 2 and 3. Stool frequency and consistency were assessed daily. Anorectal manometry, rectal sensation, and colon transit testing were performed at the end of weeks 1 and 3. Ten healthy men were studied. No significant differences in segmental or total colon transit time were noted; however, significant changes in stool frequency and trends toward decreased stool consistency were noted during sildenafil use. A trend toward reduced resting anal sphincter pressure was seen after sildenafil. Rectal volumes to first sensation and desire to defecate were significantly increased after sildenafil on test day 2 only. Additionally, volumes to desire to defecate and maximal tolerable volume were significantly increased before sildenafil on test day 2 compared to before sildenafil on test day 1. We conclude that daily administration of sildenafil is well tolerated and results in alterations in colorectal function.Presented at the Annual Meeting of the American Gastroenterological Association in New Orleans, LA, May 2004 and published in abstract form (Gastroenterology 126:A221, A36, 2004).     

Botulinum toxin A for the treatment of chronic anal fissure

Since its introduction for the treatment of strabismus, botulinum toxin (BoNT) has been increasingly used in the treatment of several disorders with excessive or inappropriate muscle contractions. The therapeutic effects of BoNT occur through the temporary chemodenervation caused by the injection into the local target muscle or skin. Modulation of muscle relaxation may be achieved by varying the dose of BoNT solution injected; most adverse effects are transient. Indeed, botulinum neurotoxin has been used to selectively weaken the internal anal sphincter as a treatment for chronic anal fissure in several randomized, controlled trials and open-label studies. The use of botulinum neurotoxin seems to be an effective and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence.     

Prospective clinical and manometric study of fistulotomy with primary sphincter reconstruction in the management of recurrent complex fistula-in-ano

Background and aims The aim of this study was to assess the results of fistulotomy with sphincter reconstruction in the management of recurrent complex fistula-in-ano in terms of recurrence and continence.Patients and methods Prospective study of 16 patients undergoing fistulotomy with sphincter reconstruction for recurrent complex fistula-in-ano was done. Preoperative and postoperative evaluation included physical examination, anal ultrasonography and anal manometry, with a 40-month follow-up. The Wexner Continence Grading Scale (0–20) was used to assess faecal continence.Results Fistulas were classified as high transsphincteric in 13 patients (81.3%), suprasphincteric in 2 (12.5%) and extrasphincteric in 1 patient (6.2%). Four patients (25%) had recurred twice or more. Eight patients (50%) complained of varying degrees of prior faecal incontinence. Their mean score decreased from 8.5 to 1.875 after surgery, and all the patients improved except for one whose score remained the same. On anal manometry, the differences between continent and incontinent patients before surgery [maximum resting pressure (MRP) 86.3 vs 57.6 mmHg, maximum squeeze pressure (MSP) 196.5 vs 138.6 mmHg] decreased after surgery (MRP 81.9 vs 63.7 mmHg, MSP 179.8 vs 159.3 mmHg). In fully continent patients, both the clinical score and manometric values were quite similar after surgery. Two fully continent patients (25%) developed occasional flatus incontinence and soiling, scoring two and three points, respectively. One patient recurred (6.25%) 6 months after surgery.Conclusion Fistulotomy with sphincter reconstruction seems to be an effective resource in the management of recurrent complex fistula-in-ano. It improves both anal continence and manometric values in incontinent patients without compromising them in fully continent ones.