Investigation of Sphincter Muscle Complex

Investigation of Sphincter Muscle ComplexAbstractBackground The exact anus reconstruction is the critical in patients with imperforate anuswhich is related to the correct diagnosis of anatomical anatomical sphincter vigour composite plant.Objectives The aim of this studyis exact investigation of the prineal region for ultrasound detection of commit and passage ofsphincter go across complex.Patients and Methods This descriptive cross-sectional study was performed at Mashhadmedical university during 2016. Transperineal sonography was done in ten patients (6-12 weekage, 8 priapic and 2 female) with imperforate anus.Results The shortest distance amongst rectal come out and grate was between 8 to 20 mm, but thedistance between rectal pouch and skin via the anal sphincter path was longer (11 to 23 mm).The multi-layer facial expression of anal tuberosity was seen in all patients except one. It had a curved and occasionally para mesial path and eccentric than muscle complex. A nal muscle sphinctercomplex could be seen in all patients with 2- 3.6 mm, occasionally asymmetric.Conclusion The multi-layer facet of anal nodule and the anal sphincter complex be the 2important sonographic findings, which suffer divulge differentiated the level of anal malformationand act as an exponent for the location of pull through.Keywords Anal sphincter muscle complex Anorectal malformation (ARM) uncut anus(IA) Child1. BackgroundColon raftcer is a Imperforate anus is one of the anorectal malformations (ARM) which ischaracterized with abnormal termination of the hindcatgut. The anus reconstruction and fecalcontinence is one of the critical aspects of treatment and surgical operation of these patients which isrelated to the correct diagnosis of sphincter complex position and the anus reconstruction in theappropriate place within the sphincter muscle complex .thither are various surgical approaches and procedures for anus reconstruction, including the mapof preoperati ve magnetic resonance imaging for diagnosis of type and level of anorectal malformation . In addition, thereare some articles about the use of MRI in the detection of sphincter complex and the anus pathguidance . However, later technique has some limitations and no available in all pediatric surgerycenters.In Imperforate anus (IA) patients, sonography is used to determine the level of disorder (low,intermediate, high), which may be divided to trine groups according to the distance betweenperineal skin spring up and rectal pouch. However, there isnt an exact cut off for theirdifferentiation and there is some diagnostic overlap . Some articles consider above 15mm as hightype and below 10 mm as low type ARM , although another numbers between 5- 25 mm are alsoconsidered as cut off point in articles. The passage of rectum from levator ani muscle intransverse view of infra-coccygeal plan is another method that can help in differentiationbetween high and low groups. Furthermore, it is a lso used for diagnosis of internal fistula(rectourethral, rectovaginal and etc) which can be reformatory in determining level of disorder .However in practice, these criteria have a little value for operation protocols and the surgicalplanning is mostly according to clinical criteria and intraoperative findings.The exact localization of anal note and muscle sphincter complex with preoperativesonography can help the surgeon to select the less invasive surgical technique and improvesurgical results.2. ObjectivesThe aims of this study is exact investigation of the prineal region for detection ultrasonic criteriaof place and pathway of muscle complex and anal sphincter in the children with Imperforateanus.3. Patients and MethodsThis descriptive cross-sectional study was performed at Dr. Sheikh pediatric Hos hellholeal during2016 after being approved by the institutional Review Board of Mashhad University of MedicalSciences, Iran and with its grant.In this study, ten patients (6-12 we ek age) with imperforate anus were selected after obtaininginformed consent from their parents. Nine patients had previous colostomy within the two geezerhoodof life and in another remaining one with rectovestibular fistula didnt previously performed it.Patients were also evaluated for associated congenital anomalies (VACTERL-H and etc.).The children were placed in lithotomy position and Foley catheter was passed from distal limb ofcolostomy to the rectum and the heave was inflated and retracted backward and fixed. Forbetter visualization of rectal pouch, normal saline was injected through fixed Foley catheter inrectum. After prep drape as the first step, transperineal sonography was done by anexperienced pediatric radiologist. Sterile gel and Betadine were used for sonographic window.The ultrasound devices used in this study was sonosite Model S Nerve with a 12 MHz linearsuperficial probe.The sonographic criteria such as shorten distance of rectal pouch from the surface of skin, distance of rectal pouch from the surface of skin in anal sphincter complex pathway , thepresence of internal fistula, multi-layered view of anal tubercle, state of anal sphincter complexwere evaluated in both sagittal and coronal planes. The Distance between rectal pouch from thesurface of skin in the shortest path and this distance in correlation with sphincter complex wereseparately measured.The distance between the rectal pouch and the surface of the skin and the presence of internalfistula were evaluated in the sagittal sonographic plane.Internal fistulas can be identified by changing of the rout the echogenic mucus of the rectumtoward urethra or vagina.The multi-layered view of anal tubercle is exactly similar to gut signature, and visualized as aperipheral hypoechoic layer with two central parallel echogenic lines just below the skin(dermis). It has vertical position than to anal pit (Fig. 1A) and is tangible only in coronal plan.Anal sphincter complex is noticeable as circu lar muscular tissue in the depth of the subcutaneousperineal area and is visible in coronal plan (Fig. 1B).4. ResultsTable 1 showed the demographic and sonographic findings of ten imperforate anus patients withwere selected for this study. Eight patients were male and other two were female.The shortest distance between the rectal pouch and the skin surface was between 8 to 20 mm, butthe distance between the rectal pouch and the surface of skin via the anal sphincter path waslonger and between 11 to 23 mm, that it was 3- 8 mm. (4.7 mm mean) longer.There were rectourethral fistula in 7, rectovaginal fistula in 1, rectovestibular fistula in 1, and inanother one patient no fistula was detected. In patient with rectovestibular fistula, anal sphinctercomplex was pushed back toward the coccygeal tip due to fecal material pressure.The multi-layer view of anal tubercle was seen in all patients except one (rectovestibular fistulapatient). The maximum outside diameter was 3-4 mm, but in patien t with cloacal anomaly, it hadabout 10 mm in sagittal plan on the posterior of prineal orifice. In often patients, the analtubercle path until center of muscle complex had a curved and occasionally parasagittal path andit wasnt straight (Fig. 1C). The visible length of multi-layer view of anal tubercle was 5-8 mm,and it attaches to the mucus of muscle complex eccentric or concentric (Fig. 1D).Anal muscle sphincter complex could be seen in all patients. The muscle complex weightiness had2- 3.6 mm which occasionally was asymmetric (Fig. 1E).5. DiscussionImperforate anus is a congenital disease with abnormal termination of hindgut which have a widespectrum of muscle sphincter complex development (from near-normal muscles to completeabsence of the sphincter muscle). Routinely, depending on the level of the obstruction in above,middle and below of muscle sphincter, this anomaly is categorized into three groups (High,intermediate, low type) . The numerous factors especially the fecal con tinence after the surgeryrelated to the diagnosis of the exact place of sphincter muscle complex .There are many articles about the role of preoperative MRI in the determining of the type andlevel of anorectal malformation which can be helpful in planning and the prediction of theprognosis and also investigation of the spinal and urethral anomalies which indirectly effect onthe management of disease and operation . MRI has also a role in these patients fordemonstration of the status of sphincter muscle complex, the symmetry of the sphincter, theperirectal fibrosis . The post-operative MRI is use to evaluate surgical results and the passage ofpulled-through catgut from the center of sphincter complex . Recently, there are some fewarticles about the use of MRI in the localization of sphincter complex and the anus pathway as aguidance instrument .The sonography is usually used to determine the level of disorder (low, intermediate, high)indirectly basis on the distance between perineal skin surface to the rectal pouch and the internalfistulae visualization. Although, this approach isnt very determinative and there are a lot ofdiagnostic overlap in this field .In review article, we find only one paper about the detection of the passage of rectum fromlevator ani muscle in transverse view of infra-coccygeal plan that can be helpful fordifferentiation of high and low groups .The pre-operative exact localization of anal tubercle and especially sphincter muscle complexwith sonography can be helpful for surgeons to select less invasive approaches that determinesthe future fecal continence of patient.In this study, with exact ultrasound investigation of prineal region, we notice two sonographicfindings which can be helpful in patients with imperforate anus to determine the proper path ofanal canal for pull-through operation. These findings were multi-layered view of anal tubercleand sphincter muscle complex.Multi-layered view of anal tubercle is exactly similar to gut si gnature and was determined as aperipheral hypoechoic layer with two central parallel echogenic lines. This view was probablythe result of fetal anal tubercle as a result non-ruptured anal membrane and non recanalized analcanal. This view wasnt seen in patient with recto-vestibular fistula. Although it had 3-4 mmdiameter, in Cloacal anomaly patient, it had about 10 mm anterior-posterior diameters in sagittalplan that probably due to fetal immix of anal and vaginal orifices.In most of patients anal tubercle wasnt straight and had parasagittal position and slightlycurvature with eccentric attachment to center of sphincter muscle complex. These can explainpathophysiology of disease.Anal sphincter and muscle complex was seen as a circular muscular tissue passel that surroundsthe echogenic mucus of gastrointestinal tract. It was visible on the coronal plane at depth ofsubcutaneous fat of the perineal area with 2-3.6 mm thickness. This complex was visible in all ofour 10 patients.In a pa tient with rectovestibular fistula, this complex pushed backward to the near of coccyxprobably due to fecal retention. Although most patients with Imperforate anus and recto-perinealfistula categorized as low type, but this patient had high type malformation because the sphinctercomplex has been pushed backward and tract of fistula lie above of muscle complex. In thispatient, based on the distance of rectal pouch to the skin (9 mm) and based on clinical findingsalone and without attention to muscle sphincter, the probability of successful surgery was toolow without sonography guide. Then, visualization of the sphincter muscle complex and rectalpouch is an important sonoghraphic findings in imperforate anus patients that can differentiatebetter the patients to the high and low malformation.In addition, the result of this study shows that the distance between rectal pouch and skin withoutattention to muscle sphincter is unreliable and can make a serious pitfalls and unawarecomplicatio ns. In all patients, the distance between rectal pouch and skin through anal tubercleand muscle complex (11mm) was longer than shorten distance between rectal pouch and skin (3-8 mm mean 4.7 mm).In lithotomy position, it is important to notice that multi-layered view of anal tubercle and analsphincter complex was only visible in coronal view and was invisible in routine sagittal andtransverse view, past it may be ignored and didnt notice to it in literatures. In the review ofarticles, we did not encounter a similar publication about the use of this findings in patients withimperforate anus, although there are many articles about the use of sonography to determine theanal sphincter complex in adults in various diseases .This is a preliminary cross sectional study with the low number of patients. In addition, thefrequency of the ultrasonic probe device were our study limitations. Exact examination ofperineal region with high-frequency probes (14 to 20 MHz) with high amount of the pat ients canprovide better and more reliable results.ConclusionThe multi-layer view of anal tubercle and the muscular bulk of anal sphincter complex are thetwo important sonographic findings, which can better differentiated the level of analmalformation and act as an index for the location of anal sphincter pull through in patientswith Imperforate anus.