Anal sphincter defects. Correlation between endoanal ultrasound and surgery

OBJECTIVE: This study was performed to (1) correlate and sphincter defects, identified by endoanal ultrasound with operative findings, and (2) define the appearance of such sphincter defects as seen at operation. SUMMARY BACKGROUND DATA: Endoanal ultrasonography is a minimally invasive method of imaging the anal sphincter complex and enables identification of anal sphincter defects. Little is known about the accuracy and limitations of endoanal ultrasound in identifying such defects. Furthermore, there are no data about the appearances of these endosonic sphincter defects as seen at operation. METHODS: Forty-four patients (40 women; age range, 26 to 80 years; mean age, 56 years) with fecal incontinence, undergoing pelvic floor repair, were investigated by endoanal ultrasound before operation. Endosonic findings were correlated with the appearances of external anal sphincter, internal anal sphincter, and intersphincteric space, at operation. Diagnosis of the site and type of defect was made by macroscopic appearances. Uncertainty about the type of sphincter defect was resolved by obtaining muscle biopsies for histology. RESULTS: All external sphincter defects seen by endoanal ultrasound (n = 23) were confirmed at operation. Twenty-one of 22 internal sphincter defects identified by endosonography also were confirmed at operation. In ten patients with a neuropathic anal sphincter complex, the morphology was normal on endosonography, and this was confirmed at operation. (Sensitivity and specificity of 100% for external anal sphincter; 100% and 95.5%, respectively, for internal and sphincter) CONCLUSIONS: These data show that endoanal ultrasound is an accurate method of identifying anal sphincter defects.     

Accuracy and reliability of transanal ultrasound for anterior anal sphincter injury

INTRODUCTION: Although transanal ultrasound has rapidly become the test of choice for the diagnosis of anal sphincter injury, the accuracy and reliability of this technique are unknown. This study evaluates the accuracy and reliability of transanal ultrasound for anterior (obstetric-related) anal sphincter injury. METHODS: Sixty-two women underwent transanal ultrasound with hard-copy images obtained at 0.5-cm intervals from the anal verge to 2.5 cm into the anal canal. All transanal ultrasound procedures were also recorded on videotape. Two experienced ultrasonographers blinded as to the patients' clinical history and examination independently reviewed the images and videotape recordings for the presence or absence of anal sphincter injury. RESULTS: The accuracy of transanal ultrasound in 22 incontinent women with known anal sphincter injury was 100 percent. The accuracy of transanal ultrasound in 20 nulliparous women with intact anal sphincters was only 35 percent but improved to 50 percent after the "real time" videotape was reviewed (P = 0.16) and further improved to 85 percent when interpretation was limited to the distal 1.5 cm of the anal canal (P = 0.004). In these nulliparous women, intact internal sphincters were more accurately predicted than intact external sphincters (95 vs. 85 percent; P = 0.24). Measurement agreement between the two ultrasonographers was 68 percent (fair; kappa, 0.26) but significantly improved to 78 percent (moderate; kappa, 0.48; P = 0.0001) when interpretation was limited to the distal 1.5 cm of the anal canal. Overall clinical agreement (final scan interpretation) was good (81 percent agreement; kappa, 0.61). Agreement was better for the internal sphincter (74 percent; fair; kappa, 0.36) than the external sphincter (61 percent; poor; kappa, 0.17; P = 0.0002). CONCLUSIONS: Although transanal ultrasound can accurately identify anterior anal sphincter injury when present, transanal ultrasound falsely identifies sphincter injury in at least 5 to 25 percent of normal anal sphincters. Only fair agreement in the interpretation of transanal ultrasound exists between experienced ultrasonographers. Both the accuracy and reliability of transanal ultrasound are significantly improved by limiting transanal ultrasound to the distal 1.5 cm of the anal canal.     

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.     

Internal and external anal sphincter anatomy as it relates to midline obstetric lacerations

OBJECTIVE: To examine the anatomy of the internal and external anal sphincters in the area of midline obstetric lacerations, to gain insight into sphincter damage and repair. METHODS: The length, craniocaudal extent, and overlap of the internal and external anal sphincters in the perineal body were measured in 17 cadavers. Further anatomic observations were made in four sets of whole pelvis cross-sections taken in the sagittal, coronal, and transverse planes. During the repair of 20 acute fourth-degree lacerations, observations were made to determine the internal sphincter visibility following birth. RESULTS: The external and internal and sphincters overlap by 17.0 mm (standard deviation [SD] 6.9), with the internal sphincter lying between the external sphincter and the anal canal. The internal sphincter extends an additional 12.2 mm (SD 5.9) cranial to the proximal extent of the external sphincter, whereas the caudal margin of the internal sphincter lies 3.7 mm (SD 7.2) cranial to the distal margin of the external sphincter. In pregnant women who sustained a fourth-degree laceration, we found that the internal sphincter can be identified as a rubbery white layer adjacent to the anal submucosa lying between the external sphincter and the anal canal. CONCLUSION: The internal anal sphincter lies between the anal mucosa and the external anal sphincter and extends more than a centimeter above the cranial margin of the external sphincter, a region where it is disrupted when a fourth-degree obstetric laceration has occurred.     

MR imaging of the anal sphincter in multiparous women using an endoanal coil: correlation with in vitro anatomy and appearances in fecal incontinence

OBJECTIVE: The aim of this study was to correlate the components of the normal female anal sphincter seen on high-resolution MR images with the in vitro anatomy and to describe the change in appearances of these components in multiparous women with fecal incontinence. SUBJECTS AND METHODS: Ten asymptomatic female volunteers (32-72 years old; mean, 54 years old) and 22 women with fecal incontinence were studied. In six patients (26-68 years old; mean, 49 years old) fecal incontinence began immediately after childbirth; in the remaining 16 patients (45-77 years old; mean, 58 years old) fecal incontinence developed 15- 30 years after childbirth. In the latter group of patients, terminal motor latencies of the pudendal nerve were measured. Imaging was done on a 0.5-T Picker Asset unit and on a 1.0-T Picker HPQ unit. A saddle geometry endoanal receiver coil was used for all imaging. T1-weighted spin-echo (720-820/20 [range of TR/TE]), T2-weighted spin-echo (2500/80 [TR/TE]), fast spin-echo (4500/96 [TR/ effective TE]), and short inversion time inversion recovery (2500/80 [TR/TE]; inversion time, 107 msec) MR images were obtained in transverse, coronal oblique, and sagittal planes. Images were assessed for integrity of the sphincter components. A nonpaired separate-variance t test was used to compare thickness of individual muscle components between patients with delayed-onset fecal incontinence and asymptomatic age-matched volunteers. Degree of muscle atrophy was correlated with degree of delay in the terminal motor latency of the pudendal nerve. RESULTS: The high resolution obtained with an endoanal coil allowed differentiation of the various muscle components of the anal sphincter complex. The internal sphincter was seen as a ring of homogeneously high signal intensity with a low-signal-intensity rim that was rich in collagen and contained neurovascular bundles. The external anal sphincter, which had low signal intensity on T1- and T2-weighted images, was shown as three components: subcutaneous, superficial, and deep. In six patients who had fecal incontinence that began immediately after childbirth, endoanal MR imaging revealed the site and extent of a tear. All tears were confirmed at surgery. In the 16 patients who had fecal incontinence that began several years after childbirth, atrophy of the external sphincter was revealed in all cases in the superficial and deep components. The internal sphincter remained normal. However, we found that the degree of atrophy of individual components of the external sphincter did not correlate with the degree of delay in pudendal nerve conduction. CONCLUSION: MR imaging with an endoanal coil reveals the integrity and bulk of individual muscle components of the anal sphincter in multiparous women with fecal incontinence.     

How reproducible are measures of the anal sphincter muscle diameter by endoanal ultrasound?

Anal endosonography is an imaging technique for the anal sphincter system and offers analysis of its muscular integrity. It is generally assumed that measurement of the thickness of muscle layers is provided by sonography; however, reproducibility of such measurements have not yet been investigated. METHODS: Study 1: In 10 healthy volunteers, endoanal ultrasound was performed independently by two experienced investigators with two different ultrasound machines, and thickness of the muscle layers of the internal and external anal sphincter was assessed in the position of the intermediate dorsal anal canal in a randomized cross-over fashion. Study 2: In a study of similar design, sonography was performed in nine healthy volunteers by two investigators independently using a single ultrasound machine in three standardized positions (proximal/intermediate/distal anal canal) and the sphincter layers assessed in the left, right, and dorsal segment. RESULTS: Study 1: Both the same investigator with different ultrasound scanners and different investigators with the same machine failed to obtain reproducible results with respect to internal and external anal sphincter muscle layer diameter (four bivariate correlations, all with p > 0.05). Study 2: Standardization of the probe position did not improve the agreement (2 x 9 bivariate correlations, all but two p > 0.05). CONCLUSION: At present, therefore, endoanal ultrasound does not provide reliable morphometric data on anal sphincter muscle diameter. This could explain previously conflicting observations of associations between anal sphincter morphometry and function.     

Prospectively evaluating anal sphincter function after ileal pouch-anal canal anastomosis

The decreased anal sphincter pressure that occurs after ileal pouch-anal canal anastomosis (IPAA) has usually been attributed to damage of the internal and sphincter. We hypothesized that the operation damages both the internal and the external anal sphincter. Resting pressure in the anal canal (a function of internal and external sphincters), anal squeeze pressure (a function of external sphincter only), and the rectal-anal inhibitory reflex (involving the internal sphincter) were measured manometrically in 10 patients with ulcerative colitis (4 women and 6 men; mean age, 33 years; range: 20 to 49 years). The patients were studied while awake before IPAA, under general anesthesia with striated muscle blockade just before incision, awake 2 months later before ileostomy takedown, and again under anesthesia with blockade just before takedown. The operation decreased maximum resting anal pressure while awake and during anesthesia with blockade. The decrease was detected in the proximal anal canal but not in the distal anal canal. In addition, the operation impaired anal squeeze pressure and abolished the rectal-anal inhibitory reflex. We conclude that IPAA damages both the internal and the external anal sphincter.     

Effect of delivery on the anal sphincter

SPHINCTER TEARS: Vaginal delivery can lead to tears in the anal sphincters. Total perineal distension following expulsion concerns less than 1% of all deliveries. Initially, sphincter tears generally go unnoticed although echographically detectable defects can be found in one-third of all primiparturients. The inner or outer sphincter may be involved alone or in combination as is seen in half of the cases. NEUROLOGICAL LESIONS: Moderate signs of incontinence (gas, urge) are frequently reversible although the long-term outcome remains unknown. In half of the cases, perineal denervation is secondary to stretch lesions of the pudendal nerve terminasions. FAVORING FACTORS: Primiparity, forceps delivery, fetal macrosomy, and certain presentations (breech, occipitoposterior) may favor sphincter lesions. DIAGNOSIS: A complete examination of the posterior perineum is required with anorectal manometry, a perineal electrophysiologic study, and a transanal ultrasound study whenever function signs are found at the post partum follow-up. TREATMENT: The therapeutic strategy is guided by the exploration results. In case of symptomatic rupture of the external sphincter, sphicteroplasty is needed followed by functional rehabilitation therapy with biofeedback. Women who have suffered traumatic lesions of the posterior perineum should be carefully followed for signs of secondary incontinence. Cesarean section may be indicated as a preventive measure in case of a new pregnancy.     

HLA-DRB1 alleles and beta 2 glycoprotein I-dependent anticardiolipin antibodies in Japanese patients with systemic lupus erythematosus

PURPOSE: This study was designed to evaluate the anatomic and functional consequences of lateral internal sphincterotomy in patients who developed anal incontinence and in matched controls. METHODS: The study includes 13 patients with anal incontinence after lateral internal sphincterotomy and 13 controls who underwent the same operation and were continent and satisfied with the results of the procedure. Patients underwent clinical evaluation, anorectal manometry, pudendal nerve terminal motor latency testing, and endoanal ultrasonography. RESULTS: Sphincterotomies were longer in incontinent patients (75 vs. 57 percent), but the resting pressure and length of the high-pressure zone were not different between groups. Surprisingly, maximum voluntary contraction was higher in incontinent patients than in continent controls (136 vs. 100 mmHg). Rectal sensation and pudendal nerve terminal motor latency were similar in both groups. The defect in the internal sphincter was wider in incontinent patients than in continent controls (17.3 vs. 14.4 mm), but these differences were not statistically significant. The thickness of the internal sphincter measured by endoanal ultrasound was identical in both groups, but the external sphincter was thinner in incontinent patients both at the site of the sphincterotomy (6.8 vs. 8.1 mm) and in the posterior midline (7.1 vs. 8.6 mm). CONCLUSIONS: Anal incontinence after lateral internal sphincterotomy is directly related to the length of the sphincterotomy. Whether secondary to preoperative sphincter abnormality or the result of lateral internal sphincterotomy, the external sphincter is thinner in incontinent patients than in continent controls.     

Endo-anal sonography in diagnosis of fecal incontinence

Endoanal ultrasound is a new imaging technique in the diagnostic work-up of patients suffering from anal incontinence. A standardised examination as well as hardware specific reference values for the sphincter muscles are of paramount importance to allow correct interpretation of the continence organ. At the University Hospital of Würzburg from 1.2.1993 to 31.7.1994 90 patients (50 male, 40 female; age: 16-81 y.) with normal continence underwent endosonographic assessment of their sphincter complex. We measured the internal anal sphincter (IAS), puborectalis muscle as well as the three separate parts of the external anal muscle (EAS). Apart from establishing reference values we found a significant increase in thickness of both EAS and IAS with increasing age. However, no correlation was seen between muscle thickness, sex, height or weight. We also examined 29 patients with a history of incontinence. 13 (45%) had a morphological sphincter defect, most of which were due to obstetric trauma or previous proctological operations. 10 (35%) patients suffered from so called idiopathic incontinence. Anal ultrasound in these patients revealed muscle hypotrophy of the structurally intact sphincters.     

Truncated human endothelin receptor A produced by alternative splicing and its expression in melanoma

PURPOSE: Traumatic sphincter disruption frequently is associated with a rectovaginal fistula, but the effect of a persistent sphincter defect on the outcome of rectovaginal fistula repair is poorly documented. We analyzed the outcome of rectovaginal fistula repairs based on preoperative sphincter status. PATIENTS AND METHODS: We identified 52 women who underwent 62 repairs of simple obstetrical rectovaginal fistulas between 1992 and 1995. Fourteen patients (27 percent) had preoperative endoanal ultrasound studies and 25 (48 percent) had anal manometry studies. Follow-up was by mailed questionnaire in 36 patients (69 percent) and by telephone interview in 12 (23 percent), for a total response rate of 92 percent. Median age was 30.5 (range, 18-70) years, and median follow-up was 15 (range, 0.5-123) months. Twenty-five patients (48 percent) complained of varying degrees of fecal incontinence before surgery. There were 27 endorectal advancement flaps and 35 sphincteroplasties (28 with and 8 without levatoroplasty). RESULTS: Success rates were 41 percent with endorectal advancement flaps and 80 percent with sphincteroplasties (96 percent success with and 33 percent without levatoroplasty; P = 0.0001). Endorectal advancement flap was successful in 50 percent of patients with normal sphincter function but in only 33 percent of patients with abnormal sphincter function (P = not significant). For sphincteroplasties, success rates were 73 vs. 84 percent for normal and abnormal sphincter function, respectively (P = not significant). Results were better after sphincteroplasties vs. endorectal advancement flaps in patients with sphincter defects identified by endoanal ultrasound (88 vs. 33 percent; P = not significant) and by manometry (86 vs. 33 percent; P = not significant). Poor results correlated with prior surgery in patients undergoing endorectal advancement flaps (45 percent vs. 25 percent; P = not significant) but not sphincteroplasties (80 vs. 75 percent; P = not significant). CONCLUSIONS: All patients with rectovaginal fistula should undergo preoperative evaluation for occult sphincter defects by endoanal ultrasound or anal manometry or both procedures. Local tissues are inadequate for endorectal advancement flap repairs in patients with sphincter defects and a history of previous repairs. Patients with clinical or anatomic sphincter defects should be treated by sphincteroplasty with levatoroplasty.     

Involvement of phosphatase activities in the run-down of GABA(A) receptor function in rat cerebellar granule cells in culture

PURPOSE: To compare the magnetic resonance (MR) imaging appearance of the anal sphincter in patients with fecal incontinence and scleroderma with that in patients with fecal incontinence alone, scleroderma alone, or neither. MATERIALS AND METHODS: The study population comprised 14 patients with fecal incontinence and scleroderma, four with scleroderma alone, 13 with incontinence alone, and six with neither. T1- and T2-weighted spin-echo, magnetization transfer contrast-weighted, and dynamic gadolinium-enhanced images were obtained and analyzed for the integrity, thickness, and length of sphincter components. Magnetization transfer contrast ratios and T2 were calculated to assess fibrosis of the internal sphincter. The percentage enhancement above baseline was calculated at 30-second intervals for the internal and the external sphincter. RESULTS: Eleven patients with incontinence and scleroderma showed descent of rectal air and feces into the anterior anal canal, with forward deviation of the significantly (P < .05) atrophied internal sphincter, which showed a slower gadolinium-enhancement pattern compared with that in other groups. Patients with incontinence alone showed no evidence of internal sphincter deviation or altered vascularity but had a significant reduction (P < .05) in deep external sphincter bulk. CONCLUSION: In patients with fecal incontinence and scleroderma, endoanal MR imaging helps delineate the anterior sphincter deformity and shows the slower gadolinium-enhancement pattern on dynamic studies of the internal sphincter.     

Third-degree obstetric perineal tear: long-term clinical and functional results after primary repair

BACKGROUND: This study was designed to investigate the long-term clinical and anorectal functional results after primary repair of a third-degree obstetrical perineal rupture. METHODS: One hundred and fifty-six consecutive women who had a primary repair of a third-degree perineal rupture were sent a questionnaire and asked to undergo anorectal function testing (anal manometry, anorectal sensitivity, anal endosonography and pudendal nerve terminal motor latency (PNTML)) RESULTS: Some 117 women (75 per cent) responded. Anal incontinence was present in 47 women (40 per cent); however, in most cases only mild symptoms were present. In 40 women additional anorectal function tests were performed and compared with findings in normal controls. Mean(s.d.) maximum squeeze pressure (31(15) versus 63(17) mmHg, P< 0.001) was decreased and first sensation to filling of the rectum (88(47) versus 66(33) ml, P=0.03) and anal mucosal electrosensitivity (4.7(1.7) versus 2.5(0.8) mA, P=0.003) were increased compared with values in normal controls. In 35 women (88 per cent) a sphincter defect was found with anal endosonography. Factors related to anal incontinence were the presence of a combined anal sphincter defect (relative risk (RR) 1.7 (95 per cent confidence interval (c.i.) 1.1-2.8)) or subsequent vaginal delivery (RR 1.6 (95 per cent c.i. 1.1-2.5)). CONCLUSION: Anal incontinence prevails in 40 per cent of women 5 years after primary repair of a third-degree perineal rupture. The presence of a combined sphincter defect or subsequent vaginal delivery increase the risk of anal incontinence.     

Sepsis associated with hematological malignancies: prophylaxis of Pseudomonas aeruginosa sepsis

Imaging of anorectal region has drastically changed during the last decade. Transrectal ultrasound and transrectal MRI can be used for staging the rectal tumours. Endoanal sonography can be applied for the classification of perianal fistulae and identification of anal sphincter defects in patients with faecal incontinence. Due to the limitations of endoanal sonography, endoanal MRI was introduced to assess the pathology related to the anal sphincter complex. Endoanal MRI seems superior to endoanal sonography. This paper describes the new developments of the imaging techniques and presents new insights in anatomy and pathology of the anorectum.     

Glutaraldehyde cross-linked collagen in the treatment of faecal incontinence

BACKGROUND: The treatment of faecal incontinence secondary to internal anal sphincter dysfunction is unsatisfactory. The aim of the study was to evaluate the efficacy of anal glutaraldehyde cross-linked (GAX) collagen injections in patients with a surgically incorrectable disorder. METHODS: Seventeen patients were studied: nine had idiopathic faecal incontinence, three had incontinence following haemorrhoidectomy, two following internal sphincterotomy, two following an internal sphincter defect from obstetric injury and one following treatment for fistula in ano. All patients were refractory to conservative treatment and were unsuitable for surgical repair. All had anorectal physiology and endoanal ultrasonography before and after GAX collagen injections. RESULTS: All patients tolerated the injection without side-effects. All patients had an intact external anal sphincter. Following injection, 11 patients showed marked symptomatic improvement. One patient reported symptomatic improvement but remained in clinical grade 3, and two reported minimal improvement. There was no improvement in three patients, but one of these had a repeat injection and showed significant improvement subsequently. CONCLUSION: Injection of GAX collagen in the anal canal is a simple and well tolerated method of treating faecal incontinence due to internal sphincter dysfunction. Early results suggest it provides an easy and reliable alternative to the currently available methods that are often unsuccessful and at best unpredictable.     

Are special investigations of value in the management of patients with fecal incontinence?

PURPOSE: The aim of this study was to determine whether special investigations significantly alter either the diagnosis or the management plan of patients with fecal incontinence assessed on the basis of a structured history and physical examination alone. METHODS: Fifty consecutive patients with fecal incontinence were prospectively studied in a tertiary referral clinic. Each patient was assessed by two clinicians who independently formulated a diagnosis and treatment plan based on the history and physical examination. The resulting 100 patient assessments were then compared with the final diagnosis and treatment plan formulated on completion of endoanal ultrasound, anal manometry, external sphincter electromyography, and defecating proctography. RESULTS: In the assessment of fecal incontinence, the addition of special investigations altered the diagnosis of the cause of incontinence based on history and examination alone in 19 percent of cases. The management plan was altered in 16 percent of cases. Special investigations were most useful in separating neuropathy from rectal wall disorders and in demonstrating the unexpected presence of internal sphincter defects and neuropathy. CONCLUSIONS: Even experienced colorectal surgeons will misdiagnose up to one-fifth of patients presenting with fecal incontinence if assessment is based on the history and physical examination alone. However surgically correctable causes of incontinence are rarely missed on clinical assessment.     

Prenatal ultrasonographic findings of intra-abdominal cystic lymphangioma: a case report

The integrity and functional capacity of the urethral sphincter is one of the important prerequisites of urinary incontinence in women. Urodynamic investigations revealed repeatedly that the maximum closure pressure in the median portion of the urethra corresponds to the maximal thickness of the external urethral sphinctor (rhabdosphincter urethrae). This striated muscle is adapted to maintain a relatively steady tonus which assists the closure mechanism of the urethra [4]. In the submitted study the authors focused attention on the ultrasonic visualization of the internal urethral sphincter in order to assess the relationship between the size of this sphincter and the stress type of incontinence (genuine stress incontinence-GSI). The investigation comprised thirty women with confirmed GSI and a control group of thirty asymptomatic volunteers. During perineal ultrasonic examination of women in a supine position by means of an ACUSON 128 XP 10 apparatus using a convex probe with a frequency of 5 MHz the authors recorded statistically significant differences in the areas and maximal thickness of the urethral sphincter in women with stress incontinence and symptom-free women. From the results ensues that the size of this muscle is much smaller in women suffering from GSI.     

The anatomical basis of anal endosonography. A study in postmortem specimens

PURPOSE: Anal endosonography is an imaging modality new to the diagnostic workup of incontinence. Interpretations even of normal endosonomorphologic findings now vary considerably. The conjoined longitudinal muscle (LM), a widely ignored structure, has until recently not been fully recognized by anal endosonography. The aim of this study, therefore, was to accurately determine the normal anatomy of the anal canal and correlate it with the findings obtained by anal endosonography. METHODS: Eight postmortem specimens of the anal canal were examined by endosonography. The findings were correlated with macroscopical dissection and gross sectional histology of the same specimens. RESULTS: The external echogenic ring is composed of two anatomical structures: the LM and the external anal sphincter (EAS). However, during anal endosonography the LM cannot always be differentiated from the EAS. Histologically, the relation of the diameters of the LM and the EAS ranged from 0.45:1 to 1.25:1. The narrow hyperechogenic ring between the inner hypoechoic layer and the external hyperechoic ring is an artificial finding that cannot be related to a distinct anatomical structure and most likely represents a sonographic interface. CONCLUSIONS: This study exactly outlines the relation of diameters of the conjoined longitudinal muscle and external anal sphincter for the first time. Until now, the LM has been underestimated in its dimensions. The role of such a thick muscular structure should be included in the conception of anal continence in the future. Especially in view of the fact that anal endosonography is increasingly used in the diagnostic workup of incontinence and fistula in ano, it is essential to understand the anatomical basis of endosonography. This study accurately delineates the sonomorphology of the anal muscles. When viewed in light findings reported here, endosonographic findings in diseases of the anal canal are nor based on a correct idea of the correlation between endosonomorphology and anal anatomy.     

Idiopathic constipation in childhood is associated with thickening of the internal anal sphincter

This study was undertaken to search for a rational basis for the use of anal dilatation and internal sphincterotomy as the treatment for chronic intractable constipation in children. Sixteen children, age 5 months to 13 years, who had constipation resistant to conservative treatment were compared with 39 age-matched controls. History and current symptoms were assessed using a standard questionnaire. Internal and external and sphincter morphology was assessed on clinical examination and by anal endosonography, using a 10-MHz rotating endoprobe to provide accurate measurement of the various components of the anal canal. The control group showed a linear correlation between the thickness of the internal anal sphincter and both age and weight, increasing from 0.4 mm in infancy to 0.9 mm in adolescence. Children who had constipation displayed significant thickening of the internal sphincter (range, 0.5 to 1.9 mm, P = .005) which was independent of the length of the history (P = .103). There was no difference in the morphology of the external anal sphincters between the groups. The finding of a hypertrophied internal anal sphincter could provide a rational basis for anal dilatation and internal sphincterotomy as treatment for idiopathic constipation.     

The effect of a normal vaginal delivery on anal function

BACKGROUND: To determine the effect of an uncomplicated vaginal delivery on anal sphincter function in primiparous women. METHODS: In a prospective study, anal manometry was performed prenatally and at 4-6 weeks postnatally in 18 primiparous women (11 undergoing vaginal delivery; seven having Cesarean section). No patient had any evidence of anal sphincter damage after delivery as determined by anal ultrasound and pudendal nerve terminal motor latency. RESULTS: Vaginal delivery was associated with a significant reduction in the squeeze pressure (SP: prenatal 269 cm H2O vs postnatal 204 cm H2O; p=0.004) but not the resting pressure (RP: prenatal 96 cm H2O vs postnatal 86 cm H2O; p=0.075). Cesarean section was not associated with any significant change in anal pressures. CONCLUSION: A normal vaginal delivery with no evidence of sphincter injury was associated with a significant effect on anal function when measured 4-6 weeks postnatally.