Assessment of a novel implantable artificial anal sphincter

PURPOSE: The aim of the study was to test a new implantable artificial anal sphincter in the porcine model. METHOD: The artificial sphincter, which includes an inflatable expander that compresses and flattens the bowel against a pillow, was implanted in 16 animals and studied for periods of up to 20 weeks. The anal sphincters were destroyed, and the efficacy of the device in rendering the animals continent was studied. RESULTS: Of the 11 animals in which the artificial sphincter was regularly closed, 8 completed the study and were continent during 85 percent of activation times. There was no evidence of ischemic injury. Major complications were related only to failure of the control pumps of the device. CONCLUSION: This study suggests that this neosphincter produces fecal continence without intestinal ischemia. At present reliability is limited only by the performance of the pump. Supported by Grant K/MRS/50/C1841 from the Scottish Office Home and Health Department, Edinburgh, Scotland. Read at the meeting of The American Society of Colon and Rectal Surgeons, Orlando, Florida, May 8 to 13, 1994, and the Association of Surgeons of Great Britain and Ireland, London, United Kingdom, May 31 to June 2, 1995.     

Results of artificial sphincter in severe anal incontinence

PURPOSE AND METHODS: Fourteen AMS 800^® (American Medical Systems, Minneapolis, MN) urinary artificial sphincters have been consecutively implanted in 13 patients with total incontinence for stool of various causes (traumatic or postoperative, 7; congenital, 3; neurologic, 2; idiopathic, 1). No proximal stoma was constructed but was already present in one patient before implantation. RESULTS: Sepsis occurred in two patients. Removal of sphincter and colostomy was necessary in three patients: one of these two had developed sepsis, one had perineal ulceration before activation of the sphincter in a severely scarred perineum, and one had severe pain in a radiation-injured anorectum. Sphincter-related failure occurred once by rupture of the cuff in a constipated woman after two years of satisfactory function. Reimplantation of a new cuff restored normal continence in this patient. After median follow-up of 20 (range, 4–60) months, nine of ten patients with a functioning sphincter were continent for stool, and five were also continent for gas. Failure occurred in one patient because the cuff was too large to occlude the anal canal. This patient is awaiting reimplantation. Four patients experienced easily controlled difficulties with evacuation of feces. Anal pressure with inflated cuff varied from 43 to 94 (mean, 58±12) cm H₂O. CONCLUSION: These results show that an artificial sphincter has a role in the treatment of severe anal incontinence when local therapies are not applicable or have failed.Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.     

Artificial anal sphincter

INTRODUCTION: Artificial anal sphincter has been proposed in severe anal incontinence when local treatment is unsuitable or has failed. The outcome after implantation of this newly developed device has not yet been determined. METHODS: Twenty-four consecutive patients (7 men; median age, 44; standard deviation, 18; range, 14–80 years) implanted since May 1996 for a minimum of six months at three centers were prospectively evaluated. Continence (scoring system, 0 (normal) to 120 (complete incontinence)), rectal emptying, and general satisfaction were assessed clinically and at anal manometry preoperatively and postoperatively at a six-month interval. The causes of incontinence included anal trauma (9 cases), neuropathy (6 cases), neurologic disorders (4 cases), congenital malformations (3 cases), and prolapse (2 cases). Median duration of incontinence was 7.5 (standard deviation, 8) years. Stomas pre-existed in two cases and was created at implantation in one. RESULTS: Median follow-up was 20 (standard deviation, 8; range, 10–35) months. Seven patients had their devices explanted, and reimplantation was successfully performed in three of these cases. At the end of follow-up, 20 (83 percent) patients had an implanted activated device. Fecal incontinence score dropped significantly from a median 106 (standard deviation, 13) preoperatively to 19 (standard deviation, 32), 25 (standard deviation, 29), and 25 (standard deviation, 25) at six months, one year, and the end of follow-up, respectively (P<0.0001). Minor and major emptying difficulties occurred in seven and two patients, respectively. A high degree of satisfaction was achieved at the end of follow-up in 18 (75 percent) of the total series. Median anal pressures at rest on manometry increased significantly from 28 (standard deviation, 17; range, 5–76) mmHg preoperatively to 60 (standard deviation, 17; range, 38–96) mmHg with a closed cuff at the end of follow-up. These pressures dropped to 30 (standard deviation, 16; range, 9–65) mmHg with an open cuff, and reocclusion time lasted a median of 4.6 minutes (standard deviation, 3 minutes; range, 38 seconds to 10 minutes). CONCLUSION: Artificial anal sphincter provided prolonged and reasonably good functional results in severe incontinence, reproducing an efficient sphincteric mechanism and allowing satisfactory anal occlusion and rectal emptying in approximately 75 percent of cases in this study. The definitive explantation rate was kept low by careful patient selection and appropriate surgical and perioperative management.Supported in part by a grant from Centre d'Etudes et de Recherches en Chirurgie.Read at The American Society of Colon and Rectal Surgeons' 100th Anniversary and Tripartite Meeting, Washington, D.C., May 1 to 6, 1999.     

Striated anal sphincter electromyography in idiopathic fecal incontinence

PURPOSE: This study was designed to determine the importance of innervation of striated anal sphincters, one of the most important structures in idiopathic fecal incontinence. METHODS: Forty-three idiopathic, fecally incontinent patients (40 women and 3 men; mean age, 57.2±11 (range, 33–77) years) underwent anorectal manometry and sphincteric electromyography. On the basis of electromyographic findings, patients were subdivided into three groups: Group A consisted of 21 patients with normal electromyography; Group B consisted of 14 patients with moderate denervation; Group C consisted of 8 patients with severe denervation. Manometric results from the patients were compared with those from 15 healthy subjects (8 women and 7 men; mean age, 35±12 (range, 15–55) years). RESULTS: Incontinent patients had a shorter anal canal (P =0.005), and anal canal pressure was lower at rest (P <0.001), at contraction (P <0.001), and at coughing (P <0.001); rectal distention and rectal compliance were reduced (maximum tolerated volume,P <0.003; compliance at 200 ml,P =0.03; at 250,P <0.005; at 300 ml,P =0.03). No statistically significant differences were found between the manometric results of the three different groups of patients. A statistically significant linear correlation was reached by comparing the clinical severity of fecal incontinence with age (P =0.02) and some other manometric parameters: the pressure of the anal canal at rest (P <0.001) and at contraction (P <0.01); rectal compliance at 50 ml (P =0.03), 100 ml (P =0.004), and 150 ml (P =0.004). CONCLUSION: Clinical severity of fecal incontinence is correlated with some manometric parameters. Severity of denervation of the anal striated sphincters does not appear to influence severity of fecal incontinence.     

Abnormal internal anal sphincter fibrosis and elasticity in fecal incontinence

PURPOSE: We aimed to investigate the changes in the proportion of collagen and in the elasticity of the internal anal sphincter in patients with neurogenic fecal incontinence. METHODS: Collagen content was studied in ten patients with neurogenic fecal incontinence (mean age, 51.5 years) and ten controls (age, 58.6 years) using histologic techniques to determine differences between incontinence and health and to determine the effect of aging. Changes in elasticity were also measured in 8 controls (mean age, 63 years) and 13 patients with neurogenic incontinence (mean age, 60 years) by recording the in vitro length-tension relationship of the freshly excised internal anal sphincter. RESULTS: Incontinent patients had a significantly higher collagen content than controls (55 percent vs.33 percent;P=0.013). In incontinent patients the amount of collagen and the patients' ages correlated significantly (P=0.001). There was a greater increase in stable tension per increase in muscle length in the strips from incontinent patients compared with controls. CONCLUSIONS: Changes in fibrous tissue content are likely to influence muscle tone and responsiveness of the sphincter in fecal incontinence.C. T. M. Speakman was supported by the Sir Alan Parks Research Foundation, The Royal College of Surgeons, and M. A. Kamm was supported by the St. Mark's Research Foundation.     

Endosonographic assessment of the anal sphincter after surgical reconstruction

PURPOSE: Patients with anal incontinence attributable to trauma are usually treated by sphincter reconstruction. Failures because of incomplete reconstruction may possibly be detected by anal endosonography which gives detailed information on the anal sphincter muscles. The aim of this study was to describe the endosonographic findings in patients after sphincter reconstruction. MATERIALS AND METHODS: Ten female patients who had undergone surgical sphincter reconstruction using an overlapping technique because of anal incontinence were studied with anal endosonography a median of six months after surgery. Five patients were fully continent, three were incontinent for flatus, and two patients were still incontinent for solid stool at the time of this study. Eight patients had also been studied with endosonography before surgery, and, in these patients, we compared the initial sonograms with the follow-up sonograms. The angular extent of the endosonographic defects in the external sphincter before and after reconstruction was measured in degrees and compared with the outcome of surgery. RESULTS: After reconstruction, continuity of the external anal sphincter was completely restored at all levels in four patients, one of whom still had anal incontinence. Continuity was partially restored in three patients: two were fully continent, while one patient, previously incontinent for stool, was incontinent for flatus. In three patients the continuity was restored at one level but a persisting defect was found at a different level. In two of these patients the grade of incontinence was unchanged. Three patients also had defects in the internal anal sphincter. CONCLUSION: After surgical sphincter reconstruction for anal incontinence, we found sphincteric defects in six patients, including four of five patients who still had some degree of incontinence. Thus, endosonography may be used for postoperative assessment and may explain the unsatisfactory results of surgery in some patients. We recommend that endosonography be also performed preoperatively, whereby the effect of the operation on the size of the sphincteric defect can be assessed.     

Tailored lateral sphincterotomy for anal fissure

PURPOSE: Most surgical texts describe the length of division of the internal sphincter during closed lateral sphincterotomy as to just above the dentate line, resulting in significant rates of incontinence. This study reviews our experience using a tailored lateral sphincterotomy by selecting the height of sphincter to be divided with the aim of preserving more sphincter. METHODS: From 1976 to March 1996, the files of 440 patients who had sphincterotomies were reviewed by an independent research assistant. After exclusions, a residual group of 352 patients had undergone tailored left lateral sphincterotomy for chronic anal fissure that had failed conservative treatment or for acute anal fissure requiring surgical intervention. RESULTS: A total of 287 patients from the group who had tailored left lateral sphincterotomy returned for review (81.5 percent). Of these, four complained of imperfect control of flatus (1.4 percent), one of minor staining (0.35 percent), and two of urgency (0.7 percent). None had incontinence of feces or leakage of stool. Five patients had repeat sphincterotomies, four for recurrence and one for a persistent fissure. CONCLUSION: The technique of tailored lateral sphincterotomy is safe, effective, and preserves more anal sphincter. It might be argued that a controlled trial comparing tailored sphincterotomy with the standard height of incision (with preprocedure and postprocedure manometry) should be performed, but the clinically significant reduction in incontinence rates using the tailored approach would seem to support its use.     

Level of highest mean resting pressure segment in the anal canal

PURPOSE: Even with development of new technologies, the mechanism of fecal continence is still not completely understood. This study evaluates the relative position of the highest mean resting pressure segment (HMRP) in the anal canal and its correlation with function in incontinent patients and in controls. METHODS: Sixteen incontinent patients (mean age, 47.1±13.9 (range, 18–63) years; 12 female) and 16 controls (mean age, 35.4±8.7 (range, 24–58) years; 12 female) were studied using a water-perfused eight-port radial catheter computer-assisted vectormanometry. Position of the HMRP was analyzed in relation to the anal verge (D ₁ ) and to the proximal functional border of the anal canal (D ₂ ). RESULTS: Controls had HMRP located more distally in the anal canal, because D ₂ was significantly higher than D ₁ (mean, 3.45±0.75 vs. 1.81±0.63 cm;P = 0.001). For incontinent patients, D ₁ and D ₂ were similar (mean, 1.86±0.75 vs.2.08±1.11 cm; not significant). Comparison of the relative position of the HMRP between patients and controls showed a more proximal location for incontinent patients than controls (mean, 49.1±12.1 percent vs.35.4±10.2 percent;P =0.002). CONCLUSIONS: Position of the HMRP is significantly more proximal for incontinent patients than for controls, and measurement of the distance from the anal verge to the HMRP in relation to the full length of the anal canal may represent another way to quantitatively assess anal sphincter function.Dr. Goes is supported at the University of Southern California by grants from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP, Brazil.     

Manometric asymmetry in the anal canal in controls and patients with fecal incontinence

PURPOSE: This study was designed to ascertain the existence of manometric asymmetry in the anal canal in controls and in patients with fecal incontinence. METHODS: A computerized manometric technique with an eight-channel perfusion catheter was used. Coefficient of variation (CV, a mathematical expression of the degree or magnitude of deviation of a set of data points from the mean) was developed in this study as an index of anal canal manometric asymmetry. RESULTS: At 1 cm from the anal verge, mean CV was 9.3 and 8.7 percent in asymptomatic control males and females, respectively. During a maximum voluntary squeeze effort, mean CV in control males was 9.3 percent and was not significantly different (P =0.28) from that in control females (7.8 percent). In 14 consecutive female patients with fecal incontinence, mean CV at rest (1 cm from the anal verge) was 21 percent and was significantly higher (P <0.01) than in control females. Similarly, during a maximum voluntary squeeze effort, mean CV in patients with fecal incontinence was 20.5 percent and was significantly higher (P <0.01) than in the female control group (7.8 percent). CONCLUSION: It is concluded that CV, a method of expressing anal sphincter manometric asymmetry, is a useful manometric parameter in the assessment of anorectal function.     

Effect of lateral sphincterotomy on internal anal sphincter function

PURPOSE: This study was designed to investigate the effect of lateral sphincterotomy on internal anal sphincter function in patients with chronic anal fssure. METHODS: Using an eight-channel perfusion catheter and computerized data analysis, a prospective manometric study was performed on patients with chronic anal fissure undergoing lateral sphincterotomy (LS). RESULTS: Mean resting pressure (MRP) in patients with anal fissure (85.1 mmHg) was significantly higher (P=0.012) than control subjects (63.3 mmHg). One week following LS there was a significant reduction in MRP (50.0 mmHg;P=0.0014), and this was maintained when reassessed five weeks later (MRP=56.4 mmHg;P=0.0019). There was no significant difference in coefficent of variation (a measure of the degree of manometric asymmetry of the anal canal) in the control group (mean, 8.9 percent) and in patients with anal fissure (mean, 7.7 percent;P=0.43). LS created a significant increase in anal canal resting manometric asymmetry when assessed at one (mean, 17.3 percent;P=0.0013) and six weeks (mean, 11.7 percent;P=0.027) after the procedure. CONCLUSION: LS produces a global and symmetric decrease in anal canal resting pressure. In addition, it produces a significant increase in manometric asymmetry of the resting anal canal by creating a detectable segmental defect.Read at the Tripartite Meeting of the Soceity of University Surgeons, Jackson, Mississippi, February 8 to 12, 1994.     

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.     

The importance of anal endosonography in the evaluation of idiopathic fecal incontinence

PURPOSE: The aim of the study was to evaluate the use of anal endosonography in idiopathic incontinence. METHODS: In 29 patients and 26 normal controls, the relationship between sonography images and physiologic parameters was studied. RESULTS: External anal sphincter function, measured as fiber density by single-fiber electromyography (P=0.0001) and pudendal nerve terminal motor latency (P=0.04), was significantly impaired in patients with idiopathic incontinence compared with controls. Both the external and internal anal sphincter could be identified by anal endosonography, and the thickness directly measured. The thickness of the external anal sphincter was significantly negatively correlated to muscle fiber density (r=–0.65,P=0.0002) and to pudendal nerve distal conduction velocity (r=–0.74,P=0.008). The thickness of the internal anal sphincter was significantly correlated to resting pressure (r=–0.67,P=0.0001). CONCLUSION: The ratio between the thickness of the external and internal sphincter muscles measured on the sonography screen was significantly reduced in patients with neurogenic incontinence compared with controls (P <0.01).     

Internal anal sphincter activity after restorative proctocolectomy for ulcerative colitis: A study using continuous ambulatory manometry

PURPOSE: The aim of this study was to further investigate continuous ambulatory anal manometry which has recently been introduced as a method for studying anorectal activity in ambulant patients, thereby avoiding many of the potential drawbacks of static techniques. METHOD: In this study continuous ambulatory manometry was used to assess the activity of the internal anal sphincter in patients who had undergone restorative proctocolectomy, and, in particular, to compare patients who had undergone conventional mucosal proctectomy with sutured endoanal, ileoanal anastomosis with patients who had undergone restorative proctocolectomy with preservation of the entire anal canal by means of stapled, end-to-end, ileoanal anastomosis without mucosectomy. RESULTS: Evidence of basal internal sphincter activity was found in only 38 percent of patients after mucosal proctectomy with sutured endoanal anastomosis, whereas all patients after restorative proctocolectomy with stapled end-to-end anastomosis and all control individuals showed such activity of the internal sphincter. Similarly, the number of sampling episodes seen in patients after mucosal proctectomy with endoanal anastomosis was significantly less (median, 0.0/hours (0–30/hours)) than the number of sampling episodes observed in patients after end-to-end anastomosis (median, 4.5/hours (1–48/hours)) or in control individuals (median, 5.6/hours (0–31/hours)) ( P <0.001). CONCLUSIONS: These results suggest that the internal anal sphincter is damaged in the course of mucosal proctectomy and endoanal anastomosis. In contrast, after restorative proctocolectomy with stapled, end-to-end anastomosis normal function of the internal sphincter is preserved.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

The anal sphincter in idiopathic megarectum

PURPOSE: This study was designed to investigate the function and morphology of anal sphincters in patients with an idiopathic megarectum. METHODS: A total of 17 patients were studied by anal endosonography and manometry when not impacted. Fourteen had previously been manually disimpacted under general anesthetic, and three had not. RESULTS: Nine of 14 patients in the former group, but none of the latter group, had disruption of one or both anal sphincter muscles on endosonography. Endosonographic changes were characteristic of those identified previously in patients following anal dilation. Low anal resting pressure, indicative of internal sphincter dysfunction, was found in a substantial proportion of patients with either an endosonographically intact or disrupted internal anal sphincter. Voluntary contraction increment, a reflection of external sphincter function, was normal in all patients. CONCLUSION: Manual disimpaction under general anesthetic appears to be associated with iatrogenic structural injury to the anal sphincters. In some patients, this may contribute to sphincter weakness. This damage may contribute to the incontinence experienced by patients with a dilated rectum.Dr. Gattuso was supported by the Alimentary Pharmacology and Therapeutics Trust and the British Digestive Foundation.No reprints are available.     

Influence of loperamide and loperamide oxide on the anal sphincter

The objective of this study was to investigate the effects of the opioid loperamide and its recently synthesized pharmacologically inactive prodrug loperamide oxide on the anal sphincter. In a double-blind, placebo-controlled crossover study, anorectal manometry was performed in 12 healthy volunteers five hours after oral bolus application of 10 mg of loperamide, loperamide oxide, or placebo. Loperamide significantly increased the threshold volumes for minimal perception and urgency to defecate (P <0.05) and raised the volume required to abolish recovery of the rectoanal inhibitory reflex (P < 0.05). These findings suggest that loperamide has a specific continence-improving action on the anal sphincter. However, anal resting pressure and maximal squeeze pressure were unaffected in our study and do not seem to be responsible for this effect. The effects under loperamide oxide showed a similar tendency but were without statistical significance.     

Traumatic anal incontinence

PURPOSE: This study was designed to describe the surgical technique and discuss the possible beneficial role of unilateral gluteus maximus transposition supplementing and supporting a tensile-direct anal Sphincteroplasty. METHODS: Based on our experience with bilateral gluteus transposition, direct apposition of the remaining muscular ends combined with unilateral gluteus transposition (to avoid the tendency of the sphincter ends to separate) was undertaken in two patients with severe destruction of more than half of the anal muscular ring. RESULTS: Both postoperative courses were uneventful. Three months after colostomy closure, both patients were classified as Pescatori's B1. CONCLUSION: As with any other combined surgical technique, the benefit derived may be attributed entirely to one of the procedures, but it is our impression that the gluteus transposition was worthwhile in achieving satisfactory repair.Presented at the Fourth Biennial Congress of the European Council for Coloproctology, Marseille, France, May 27 to 29, 1992.     

Effect of electrostimulation on sphincter function in neurogenic fecal continence

PURPOSE: This study was designed to examine the effects of electrostimulation on sphincter function. METHODS: Electric stimulation was performed twice a day for 30 minutes over a 12-week period on 10 patients with neurogenic fecal incontinence. Anal manometry was repeated after 6 and 12 weeks. RESULTS: Two patients experienced some improvement. Mean resting pressure was increased by 0.6 (–5.8 to +5.3) kPa and mean squeezing pressure by 0.3 (–1.6 to +2.6) kPa. All values remained below continent levels. An increase in squeezing pressure after both 6 and 12 weeks was recorded in only one patient. CONCLUSION: Electrostimulation does not improve internal or external sphincter function. There is no indication that it will do so in the long term either.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

Gradient of pressure and time between proximal anal canal and high-pressure zone during internal anal sphincter relaxation

PURPOSE: The normal response to rectal distention is a relaxation of the proximal anal canal (PAC). We hypothesized that this mechanism would require a gradient of pressure and time to preserve continence. METHODS: Sixteen volunteers (10 male), mean age, 41.5 (range, 24–60) years, were studied using an eight port axial catheter with a compliant balloon at its tip. Relaxation was induced by a small volume of rectal distention (15–30 ml of air) and was recorded until recovery of resting anal pressure (RAP). Duration of relaxation was measured until recovery of RAP. Amplitude of relaxation was determined between RAP before rectal distention (RAP-BR) and pressure at the point of maximum relaxation (RAP-PMR). Gradient of pressure was determined by comparing RAP-PMR in the high-pressure zone (HPZ) and PAC. Contraction in the distal anal canal was interpreted as external anal sphincter contraction (EASC) and was compared with RAP-PMR in the HPZ. RESULTS: Relaxation was significantly greater in PAC than in HPZ (50vs. 36 percent;P=0.001). RAP-PMR was significantly higher in HPZ than in PAC (30.7vs. 12.6 mmHg;P= 0.001). EASC was observed in six patients and did not show significant difference with RAP-PMR in HPZ (39.7vs. 36.3 mmHg; not significant). Relaxation began at the same time in all levels but lasted significantly longer in PAC compared with HPZ (13.5vs. 9.4 sec;P=0.003). CONCLUSION: Anal relaxation induced by small volume rectal distention involves a gradient in the pressure and time of relaxation between PAC and the HPZ.Dr. Goes is supported at the University of Southern California by grants from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP, Brazil.Read at the meeting of The American Society of Colon and Rectal Surgeons Investigation/Surgical Research Forum, Montreal, Quebec, Canada, May 7 to 12, 1995.     

Risk of sphincter damage and anal incontinence after anal dilatation for fissure-in-ano

Follow-up was performed two to six years after anal dilatation for fissure-in-ano in 32 consecutive patients who had not undergone additional anal surgery. All patients were interviewed and asked specifically about impairment of flatus or fecal control and its possible relation to the anal dilatation. Anal dilatation was followed by minor anal incontinence in 12.5 percent of the patients. Anal endosonographic follow-up was accepted by 20 patients, and sphincteric defects were found in 13 (65 percent) of those. Two patients with anal incontinence had internal sphincter defects. Sphincteric defects were also found in 11 of the 18 continent patients who underwent sonography: internal sphincter defects in nine, external sphincter defect in one, and combined defects of both sphincter muscles in one. In conclusion, anal dilatation results in sphincter damage in more than half of patients, but few of them develop anal incontinence.     

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.