A comparison between electromyography and anal endosonography in mapping external anal sphincter defects

Mapping of the external anal sphincter by anal endosonography was compared with the electromyographic findings in 15 patients with fecal incontinence after perineal trauma. Both examinations showed no defect in three patients. In the 12 patients with muscle defects, there was agreement on the quadrant involved in all patients. In seven patients, there was total agreement in the hours of the defect, in four there was a one hour discrepancy, and in one there was a two-hour difference in the measured defect. Correlation between the two techniques was high (r =0.96; P<0.01). Anal endosonography is better tolerated by patients than electromyographic mapping and is a useful technique for assessing posttraumatic defects of the external anal sphincter.Drs. Law and Kamm are supported by the St. Mark's Research Foundation.Study performed at St Mark's Hospital, London, United Kingdom. Reprints will not be available.     

Anal sphincter imaging in fecal incontinence using endosonography

Clinical anal examination, manometry (resting and squeeze pressures), and single-fiber electromyography were compared with endosonography of the anal sphincters in 14 patients with fecal incontinence. Technical aspects of the procedure and normal imaging of the puborectal muscle and both sphincters were defined. Defects in both sphincters were seen in nine patients. The defect is visualized as a clear discontinuity in the muscular ring. Compared with the conventional studies, anal endosonography gave significant information in six patients (four male patients after perianal surgery and two women), showing sphincter defects in five patients and integrity of the sphincters in another one. This information obtained by endosonography was important in understanding the type and extension of the lesion and deciding upon the surgical repair. Anal endosonography is an imaging technique of the sphincters that can assess their integrity in fecal incontinence.     

Artificial anal sphincter

PURPOSE: This study was undertaken to evaluate the use of a fully implanted artificial anal sphincter for management of severe fecal incontinence. METHODS: An artificial anal sphincter was implanted in 12 patients who failed conventional management for severe fecal incontinence. Careful patient follow-up was recorded during a mean 58-month follow-up. Patients underwent preoperative and postoperative manometric assessment. Functional and patient satisfaction evaluations were obtained by mailed questionnaire. RESULTS: Three infections and three mechanical complications occurred in four patients (33 percent). A successful outcome was achieved in nine patients (75 percent). Postoperative manometric studies documented establishment of an elevated high-pressure zone compared with preoperative resting pressures. Seven patients returned a detailed functional assessment and patient satisfaction questionnaire at a mean of 40 months postsphincter activation. All seven patients reported continence to solid stool. Two patients had some problems with control of liquid stool, and three had occasional incontinence to flatus. Six of the seven patients rated their bowel control as good to excellent. All seven respondents were satisfied with their functional improvement. CONCLUSIONS: Early experience with an artificial anal sphincter has demonstrated that continence can be restored with acceptable morbidity in patients with severe fecal incontinence.Supported by American Medical Systems, Minneapolis, Minnesota.Presented in part at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

Damaging effects of anal stretching on the external anal sphincter

Purpose: This study was undertaken to investigate the effects of anal stretching on anal pressures and damage to the external anal sphincter. METHODS: This study was performed on 37 guinea pigs. Animals were divided into three groups: control group, quick stretching group, and continuous overstretching group. Anal stretching was conducted by an 8-F Foley^® catheter balloon. RESULTS: It was found that if the muscle was stretched from 100 to 300 percent of its original length, anal resting pressure (ARP) kept relatively steady, but anal contracting pressure (ACP) gradually increased; from 300 to 370 percent, a sharp ARP increase was developed, but ACP gradually decreased to zero; beyond 370 percent, ARP remained unchanged (plateau phase). By histologic examination, it was revealed that when the muscle was stretched at the ARP plateau phase, an ischemic zone of necrosis and an edematous zone of necrosis could be clearly identified in the muscle. CONCLUSION: This study shows that length of the external anal sphincter definitively influences muscle strengths, and severe anal stretching will result in muscle damage. These results imply that the sphincteric muscle complex in high or intermediate anorectal anomalies may be injured during present conventional surgical approaches.Presented at the annual meeting of the British Association of Pediatric Surgeons, Sheffield, United Kingdom, July 26 to 28, 1995.     

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).     

Precise anorectal sphincter dilatation—Its role in the therapy of anal fissures

For the past 20 years, internal anal sphincterotomy has generally been considered to be the standard operation for an anal fissure. We sought an alternative form of treatment because of the wound complications inherent in this operation. Anal dilatation, precisely performed with a Parks' retractor opened to 4.8 cm or with a 40mm rectosigmoid balloon, has been found to cure successfully the fissure in 93 percent and 94 percent, respectively, of each group and to be associated with fewer complications.Read at the meeting of The American Society of Colon and Rectal Surgeons, Boston, Massachusetts, May 12 to 17, 1991.     

Anal sphincter repair improves anorectal function and endosonographic image

PURPOSE: This study investigated the effect of anal sphincter repair on fecal continence in relation to anal endosonography and anal manometry. METHODS: Eighteen patients (7 male, 11 female) with anal sphincter defects and complaints of fecal incontinence (5), soiling (= liquid discharge; 3), or both (10) were studied before and after sphincter repair with endosonography and anal manometry. Complaints were the result of obstetric trauma (7), surgical trauma (7), both (3), and other trauma (1). Five patients had previous surgery. Preoperative endosonography showed a defect of both sphincters in nine patients, a defect of the external anal sphincter in five patients, and a defect of the internal anal sphincter in four patients. An overlapping sphincter repair was performed. RESULTS: Postoperatively and subjectively (S; patient's view), 13 (72 percent) patients became continent or improved; in 5 (28 percent) patients the complaints were unaltered. Objectively (O) (incontinence or soiling frequency), these figures were 12 (67 percent) and 6 (33 percent). Postoperative endosonographic images improved in 14 (78 percent) patients; defects of the sphincters (almost) disappeared (4) or were smaller (10). In the other four patients, images were unchanged. In two patients, overlapping of the muscle was clearly visible with anal endosonography. Clinical result (subjective (S) and objective (O)) of sphincter repair correlated with changes in anal endosonography (S,r=0.64,P <0.004; O,r=0.51,P=0.03) and anal manometry (S,r=0.54,P=0.038; O,r=0.44,P=0.09 (not significant)) and not with pudendal nerve latency. CONCLUSION: In 78 percent of our patients, endosonographic sphincter defect had diminished or disappeared after sphincter repair. There was a good correlation between clinical effect of sphincter repair and changes with anal endosonography and anal manometry. Postoperative persistent incontinence is attributable to remaining sphincter defects. Anal endosonography should be performed as a routine procedure in patients with fecal incontinence or soiling, also after failed surgery.Presented at the meeting of the American Gastroenterology Association, New Orleans, Louisiana, May 15 to 18, 1994.     

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.     

Morphology of dynamic graciloplasty compared with the anal sphincter

Dynamic graciloplasty for fecal incontinence includes gracilis muscle transposition around the anal canal as a new sphincter and subsequent electrical stimulation. The aim of electrical stimulation is to transform the gracilis fast-twitch, fatigue-prone fibers into slow-twitch, fatigue-resistant fibers to achieve a sustained tonic contraction. The latter is considered essential for sphincter function. Therefore, the following features of transposed gracilis muscle morphology were studied in nine patients before and after electrical stimulation: 1) the percentage of Type I fibers, 2) the lesser diameter of these fibers, and 3) the positive collagen staining area. Furthermore, the external anal sphincter and gracilis muscle histology was investigated in six autopsy cases. The mean percentage of Type I, slow-twitch, fatigue-resistant fibers in transposed gracilis muscle increased from 46 percent before electrical stimulation to 64 percent (P <0.01, paired Student's t-test) after electrical stimulation. The mean lesser diameter of these fibers did not change significantly (from 32 to 29 m), and the mean percentage of collagen increased from 4 percent before electrical stimulation to 7 percent (P <0.01) afterward. The external sphincter in cadavers demonstrated a predominance of Type I fibers (80 percent) with a lesser diameter of 23 m and a high percentage (12 percent) of collagen. Gracilis muscle histology was uniform at six different sample sites in these cadaver dissections. We conclude that electrical stimulation induces histologic changes in transposed gracilis muscle, allowing this muscle to function as an external anal sphincter.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.These studies were financially supported by the Ministry of Trade and Industry and the Funds for Research in Medicine (Ontwikkelingsgeneeskunde), The Netherlands.     

Lateral sphincterotomy compared with anal advancement flap for chronic anal fissure

PURPOSE: This study was designed to assess differences between lateral internal anal sphincterotomy and anal advancement flap for chronic anal fissure. METHODS: Forty patients with chronic anal fissure were prospectively studied. Patients randomized to the sphincterotomy group (n=20; median age, 34 (range, 16–61) years) underwent lateral internal anal sphincterotomy. Patients randomized to the flap group (n=20; median age, 32 (range, 20–44) years) had an anal advancement flap. RESULTS: All fissures in the sphincterotomy group healed following surgery compared with three patients that failed to heal in the flap group (P = 0.12). No patient in either group was incontinent to any degree following surgery. Patient satisfaction with surgery was similar in both groups. CONCLUSION: Anal advancement flap is an alternative to lateral sphincterotomy for chronic anal fissure.     

Diagnosing anal sphincter injury with transanal ultrasound and manometry

PURPOSE: This study was undertaken to evaluate how well anorectal manometry and transanal ultrasonography diagnose anal sphincter injury. METHODS: Anorectal manometry and transanal ultrasonography were performed in 20 asymptomatic nulliparous women and 20 asymptomatic parous women, and the results were compared with those obtained in 31 incontinent women who subsequently underwent sphincteroplasty and, thus, had operatively verified anal sphincter injury. By using computerized manometry analysis, mean maximum resting and squeeze pressures, sphincter length, and vector symmetry were determined in all women. All transanal ultrasounds were interpreted blinded as to the patient's history, physical examination, and manometry results. RESULTS: Manometric resting and squeeze pressures were significantly higher in the asymptomatic nulliparous women than in the asymptomatic parous women, and both groups had significantly higher pressures than the incontinent women ( P <0.001). Anal sphincter length and vector symmetry index were significantly decreased in incontinent women compared with asymptomatic women ( P <0.01). Decreased resting and squeeze pressures suggestive of possible sphincter injury were found in 90 percent of incontinent women with known anal sphincter injury. Decreased anal sphincter length and vector symmetry were found in only 42 percent of women with known anal sphincter injury. Transanal ultrasound was able to identify 100 percent of the known sphincter injuries but also falsely diagnosed injury in 10 percent of the asymptomatic nulliparous women with intact anal sphincters. False identification of sphincter injury increased when transanal ultrasound scanning was performed proximal to the distal 1.5 cm of the anal canal. CONCLUSION: Although nonspecific, decreased resting and squeeze pressures were found in 90 percent of patients with anal sphincter injury. Decreased anal sphincter length or vector symmetry index were present in only 42 percent of patients with known sphincter injury. When limited to the distal 1.5 cm of the anal canal, transanal ultrasound identified all known sphincter injuries but falsely identified injury in 10 percent of women with intact anal sphincters. Transanal ultrasound in combination with decreased anal pressures correctly identified all intact sphincters and 90 percent of known anal sphincter injuries.Read at the meeting of The American Society of Colon and Rectal Surgeons, Orlando, Florida, May 8 to 13, 1994. Winner of the New England Society of Colon and Rectal Surgeons Award.     

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.     

Recovery of anal sphincter function following transabdominal repair of rectal prolapse: Cause of improved continence?

Twenty-eight patients with complete rectal prolapse underwent anorectal manometry before and 6 months and 1–2 years after abdominal rectopexy and sigmoid resection in a study of the mechanisms responsible for postoperatively improved anal continence. Preoperatively, 22 patients reported defective anal control. Seven patients (all with minor incontinence) regained normal control and eight other patients achieved improved continence after surgery. Anal resting, squeeze, and voluntary contraction pressures were significantly lower for defective than for normal control, with a significant rise in these pressures at 6 months after the operation, except for those incontinent patients in whom continence was not improved. No further pressure rise was seen later. Improvement of continence was not accompanied by changes in rectal sensation or reflexive functions of the internal anal sphincter. These results suggest that recovery of the resting and voluntary contraction functions of the sphincter muscles was the cause of continence improvement observed after surgery. Anal manometry was unable to predict outcome of function. Therefore, supplementary procedures for restoration of continence are not advisable, although patients with only minor incontinence are likely to regain full continence after rectopexy alone.     

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.     

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.     

Pediatric stirrups for anorectal surgery

A stirrup system to facilitate anorectal operation in a pediatric patient is described.     

Transanal ultrasound and anorectal physiology findings affecting continence after sphincteroplasty

PURPOSE: This study was undertaken to evaluate endosonographic and physiologic determinants of fecal continence after sphincteroplasty. METHODS: Sixteen female patients with severe fecal incontinence were treated with overlapping sphincteroplasty. Mean postoperative follow-up was 12 (range, 3–48) months. All patients underwent preoperative and postoperative transanal endosonography and anal manometry. Bilateral pudendal nerve terminal motor latency determinations were performed in each patient. A physiologic continence score was used to assess stool control. RESULTS: Postoperatively, continence was worse, unchanged, and improved in one, five, and ten patients, respectively. An inverse correlation was noted between endosonographic sphincter discontinuity postoperatively, in degrees, and the change in fecal continence after overlapping sphincteroplasty (r =–0.51;P =0.04). Postoperative increases in sphincter resting (r =0.6;P =0.02) and squeeze (r -0.54;P =0.03) pressures correlated with improved fecal continence. Mean pudendal nerve terminal motor latency (r = –0.34;P =0.20) and changes in anal sphincter length at rest (r =0.41;P =0.11) and squeeze (r =0.33;P =0.20) after sphincteroplasty did not significantly correlate with the change in continence. Patients with intact endosonographic anatomy postoperatively and bilateral, unilateral, or no evidence of pudendal neuropathy had a mean change in continence score of 0.5, 1.8, and 2.2, respectively (P =0.48). CONCLUSIONS: Endosonography after sphincteroplasty can identify residual sphincter defects that are significant in terms of fecal continence. Restoration of anal canal resting and squeeze pressures was related to improved fecal control after overlapping sphincteroplasty. Mean pudendal nerve terminal motor latency was not significantly related to poor postoperative continence. A trend toward less improvement in fecal continence was noted with bilateral pudendal neuropathy.Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996, and at The Tripartite Meeting, London, United Kingdom, July 8 to 10, 1996.     

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.     

Relationship between clinical symptoms of anal incontinence and the results of anorectal manometry

The aim of this work was to analyze clinical symptoms in light of anorectal manometry results. We compared the frequency of clinical symptoms in relation with the presence or absence of functional anomalies. Using this methodology, the following relationships may be suggested: the need to wear a pad, with a decreased resting pressure at the upper part of the anal canal; the inability to delay rectal evacuation, with decreased anal voluntary contraction; interference of incontinence with social activities, with decreased duration of anal voluntary contraction; urinary symptoms, with an increased threshold volume of rectal distention needed to elicit the rectoanal inhibitory reflex; and complete rectal prolapse, with reduced length of the anal canal.     

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.