Radiol Oncol 2003; 37(1): 17-22. Endosonographic and manometric assessment of the anal sphincters after ileal pouch-anal anastomosis Iwona Sudoł-Szopińska1, Adam Ciesielski2, Krzysztof Bielecki2, Lech Baczuk2, Wiesław Jakubowski1,Wiesław Tarnowski2 1Imaging Diagnostic Department, Second Medical Faculty, Warsaw, Poland 2Postgraduate Education Medical Centre, Department of General Surgery, Warsaw, Poland Background. The aim of this study was to compare endosonography and manometry of the anal sphincters in patients after ileal pouch-anal anastomosis (IPAA). Patients and methods. Ten patients aged between 23 and 50 years with IPAA performed for ulcerative co-litis were examined with anal endosonography (AES) and manometry. Results. AES visualised abnormal image of the internal anal sphincter (IAS) in 9 patients (90%). Defects of the external anal sphincter (EAS) and puborectalis muscle (PR) were shown in 4 patients (40%). In 5 pa-tients (50%) correlation between endosonographic and manometric assessment for the all analysed muscles: IAS, EAS and PR was found. In 4 cases (40%) both methods correlated with the evaluation of the EAS on-ly and in 1 patient (10%) no correlation was found. Correlation between both methods for the IAS was found in half of the patients (50%) while in the evaluation of the EAS and PR dynamic activity, it was found in 9 cases (90%). Conclusions. Anal endosonography and manometry allow us to assess the morphology as well as the func-tion of the anal sphincters in patients with IPAA. The methods mentioned above show high correlation in the assessment of the EAS function (9 cases; 90%) whereas in the case of IAS, manometry frequently (5 pa-tients; 50%) does not confirm endosonografically detected defects. Key words: colitis, ulcerative; anus-ultrasonography; manometry; proctocolectomy, restorative Received 4 September 2002 Accepted 11 September 2002 Correspondence to: Iwona Sudoł-Szopińska, M.D., Ph.D., Zakład Diagnostyki Ultrasonograficznej, Wojewódzki Szpital Bródnowski, 03 285 Warszawa, ul. Kondratowicza 8: Phone +48 5017 16407; E-mail: mdyvonne@wp.pl Introduction Ileal pouch-anal anastomosis (IPAA) has be-come the operation of choice for most pa-tients with ulcerative colitis. Patients prefer this form of therapy to formation of the sto-my although it is accompanied by a notice-able percentage of anal incontinence which affects even 84% of patients.1-4 Anal sphinc-ters defects can be partially responsible for this high incidence of incontinence. The aim 18 Sudoł-Szopińska I et al. / Endosonography and manometry of the anal sphincters of this study was to visualise the suspected defects of the anal sphincters on anal en-dosonography (AES) and to compare them with the results of the ano-rectal manometry. Patients and methods Ten patients (8 women and 2 men) aged be-tween 23 and 50 years (median age 33.2 years) with J - pouch and stapled IPAA per-formed without mucosal dissection for the ul-cerative colitis were examined with the use of anal endosonography and ano-rectal manom-etry. Examinations were performed after 3-11 years after IPAA formation (mean 5,5 years). None of them had any operation on the anal canal prior to IPAA formation and none of the women had a complicated delivery. In order to assess the severity of anal inconti-nence, the Jorge- Wexner’s grading system was used.5 Anal endosonography was per-formed with the use of Bruel and Kjaer scanner type 1846 with a 7.0 MHz rotating endo-probe that provides a 360° image. The probe was covered with a plastic cone with an ex-ternal diameter of 17 mm, which was filled with degassed water for acoustic coupling. The cone was covered with a condom. Patients were examined in the prone position, and no preparation was required prior to AES. As the probe was withdrawn from the anal canal, images of the puborectalis muscle (PR), external anal sphincter (EAS) and inter-nal anal sphincter (IAS) were documented. The thickness, echogenicity and outlines of the IAS and echogenicity of the EAS were assessed on each level of the anal canal. The thickness of the IAS was measured at 3 and 9 o’clock position of the coronal plane of imag-ing, using electronic calipers on the monitor. The normal IAS was defined as a homoge-nous, hypoechoic ring with thickness greater than 1mm.6 Increased and nonhomogenous echogenicity and ill-defined margins of the IAS were diagnosed as abnormal. The EAS Radiol Oncol 2003; 37(1): 17-22. was identified as non-homogenous muscle with striated echogenicity and was defined as abnormal if hypoechoic areas were visible within it.6 Dynamic activity of EAS and PR was assessed as good (++), poor (+) or lack (0) of contraction using a subjective scale which depends on comparing their image at rest and during maximal voluntary contraction. Anorectal manometry was performed with the patients in the left lateral position. No en-ema was given. A lower gastrointestinal manometry system (PC Polygraf HR; Synec-tics Medical Stockholm, Sweden) with four -lumen polyvinyl chloride catheter with rectal distending balloon (AMC4-B; Zinectics Medi-cal, Stockholm, Sweden) was used. Perfusion ports were located in 1 cm intervals arranged circumferentially. After positioning at the depth of 6 cm from the anal verge the cat-heter was allowed to accommodate for sever-al minutes. Maximum resting anal pressure (MRP), maximum voluntary pressure (MVP) and maximal duration of squeeze (D) were recorded. Pouch capacity was also recorded by distending air-filled, thin- walled balloon positioned 6 cm within the pouch to assess maximal tolerable volume (MTV). Results The results of anal endosonography and ano-rectal manometry are presented in Tables 1 and 2. In anal endosonography, thinning of the IAS was visible in all but one patient (9 cases; 90%). Increased echogenicity of the IAS in 6 (60%) and ill-defined borders was detected in 3 patients (30%). Echogenicity defect of the EAS was visible in 3 cases (30%). Dynamic examination revealed good EAS and PR contraction in 6 patients (60%), poor in 3 (30%) and lack in 1 patient (10%). Manometry revealed decreased maximum resting anal pressure suggesting dysfunction of the IAS in 3 cases (30%), decreased maxi- Sudoł-Szopińska I et al. / Endosonography and manometry of the anal sphincters 19 Table 1. Anal endosonography in patients with IPAA No IAS Echogenicity defect of the Thickness Increased Il-defined Dynamic exam [mm] echogenicity borders EAS 1. BA <1 + ++ 2. EB <1 + + ++ 3. GP <1 ++ 4. ME <1 + + 5. NM 2.5 ++ 6. SK <1 + + 7. ST <1 + + + + 8. WE <1 + + ++ 9. WM <1 ++ 10. Wm 0 + + + 0 Table 2. Ano-rectal manometry in patients with IPAA (sequence of patients as in Table 1) No MRP* MVP D MTV I 1. BA 30 180 16 150 8 2. EB 60 180 48 100 0 3. GP 60 200 40 190 0 4. ME 60 81 40 150 0 5. NM 80 110 30 200 6 6. SK 45 125 64 120 12 7. ST 60 200 40 350 0 8. WE 60 257 80 /-/ /-/ 9. WM 75 148 50 260 0 10. Wm 30 45 /-/ 160 9 Normal values 60-80 100-250 >40 >150 0 *MRP - Maximum resting anal pressure [mmHg], MVP -Maximum voluntary pressure [mmHg], D - Maximal duration of squeeze (sec) MTV- Maximal tolerable volume [ml], I - Jorge-Wexner’s fecal incontinence severity score (points) /-/ - not assessed: in one patient - MTV and I - because of pouch-vaginal fistula and in one patient - D - be-cause of low MVP mal voluntary anal pressure in 3 patients (30%), implying dysfunction of the EAS and PR, and in another 2 patients (cases 1 and 5 from the Table 2) the shortage of the maximal duration of squeeze indicating dysfunction of the EAS and PR was revealed as well. In all cases manometry correlated with clinical examination (Table 2). Correlation be-tween endosonography and manometry was found in 5 patients (50%) for all analysed muscles (IAS, EAS and PR), and in 4 patients (40%) for the EAS and PR only. No correlation between the methods was found in 1 patient (10%). Although in this case AES showed thin, hyperechoic, with ill-defined marginated IAS, and also poor contraction and scars within EAS, manometry revealed preserved function of the anal sphincters. The analysis of the each assessed element of the IAS (thickness, echogenicity and bor-Radiol Oncol 2003; 37(1): 17-22. 20 Sudoł-Szopińska I et al. / Endosonography and manometry of the anal sphincters ders) showed that normal image of this sphincter, which was observed in only 1 patient correlated with its preserved function in manometry. However, the abnormal image, which was visible in the remaining 9 patients correlated with its dysfunction in manometry in 4 cases only (44.4%). This included 2 out of 3 patients with thin IAS (66.6% correlation) and 2 out of 6 patients who had thin and hy-perechoic IAS (33.4%). Correlation between AES and manometry in the assessment of the EAS and PR function was found in the majority of the patients (9 cases; 90%). In the remaining one case, en-dosonographic image of the PR and EAS showing their poor contraction and scars did not corresponded with their preserved func-tion (case 7 from the tables 1 and 2). Discussion Anal endosonography, apart from magnetic resonance imaging using endorectal coil, is the most appropriate method to assess the morphology of the anal sphincters. Ileal pauch-anal anastomosis has become an operation of choice for most patients with ulcerative colitis.2,4,7-9 Patients prefer the pelvic reservoir to an ileostomy, although the results of the IPAA formation are not fully satisfactory, its greatest problem being the Table 3. Jorge-Wexner’s grading system of anal in Type Frequency of Incontinence Never* Rarely Solid 0 1 Liquid 0 1 Gas 0 1 Wears pad 0 1 Lifestyle alteration 0 1 *Never = 0 Rarely L 1/month Sometimes L 1/week, 3 1/month Usually 3 1/day Radiol Oncol 2003; 37(1): 17-22. loss of continence after treatment.2,4,7-9 The images of the anal sphincters and their func-tion after IPAA have not been precisely in-vestigated so far. Individual reports in the literature concentrated on the results of anal endosonography and ano-rectal manometry after IPAA and show the thinning of the IAS and the reduction of the maximum anal rest-ing pressure in most of the operated pa-tients.2,7,9 These disturbances are present after endoanal manipulation (handsewn transanal anastomosis with or without mucosecto-my) as well as after stapled anastomosis.4,7 Nevertheless, avoidance of endoanal proce-dures and transabdominal anal pursestring placement and stapled IPAA without muco-sectomy provides higher anal resting pres-sure comparing to endoanal manipulations.4,7 The thinning of the IAS was also the most fre-quent abnormality we observed in our study in all but one patient (9 patients; 90%). There are several reasons leading to the thinning of the IAS, such as denervation, ischemia or a direct trauma to the IAS as a result of transanal mucosectomy, and also, as men-tioned above, hand sewn anastomosis.2,7,9 During the IPAA, the formation dissection and mobilisation of the anorectum is respon-sible for the IAS trauma as a result of damage to the extrinsic autonomic nerve supply, which plays an important role in the IAS function.3 Additionally, the transsection of Sometimes Usually Always 23 4 23 4 23 4 23 4 23 4 Sudoł-Szopińska I et al. / Endosonography and manometry of the anal sphincters 21 the rectal wall at the level of the levator ani muscles may cut through the layer of spe-cialised circular muscle which forms the IAS. This could cause damage of the intramural nerve plexus and blood supply.2 The sphinc-ter trauma at this level is presumably in-evitable.2 In our study only one patient had a normal image and pressure of the IAS. In the remain-ing 9 cases, endosonography suggested its degeneration in 6 out of 9 patients. Correlation with manometry was found in less than half of these patients (4 out of 9; 44.4%). Gene-rally, manometry revealed preserved function of the sphincters in the majority of the pa-tients. Our results were as in other studies, for instance in Stryker et al.,7 who found no differences in anal canal resting and squeeze pressures between patients with IPAA and controls as well as no correlation between them regarding clinical data. Although our small study does not lead to definite conclu-sions, such a high incidence of patients with abnormal image of the IAS, but without func-tional disturbances is striking. Undoubtedly, our group of patients with aged 33.2 years on the average is young, and it is well known that the thickness of the IAS normally in-creases with age.10 So in the young population thickness is the smallest. It is expected to be over 1.9 mm at the age of 19-65 years.10 Norms of the thickness of the sphincter may need to be verified. Increased echogenicity of the IAS was the most likely consequence of surgery and represented fibrosis of the sphincter. The possibility of the IAS degeneration related to age, which manifests typical-ly as thinning, increased echogenicity, and ill-defined borders of the IAS, is excluded be-cause of the young age of our patients. On the other hand, there were predominantly women in our group of patients (8 versus 2) and it has been shown in the literature11 that a relevant number of women, who have had uncomplicated deliveries, endosonographi-cally show sphincter defects. The results of the findings would be more reliable if pa-tients had been examined before and after the pauch procedure, which was not the case in our study. Dynamic anal endosonography appeared a valuable adjunct to the examina-tion at rest. Dynamic endosonography is es-pecially valuable in diagnosing anal sphinc-ters trauma, and shows high correlation with electromyography.10 In our study, correlation between dynamic anal endosonography and manometry was found in 9 cases (90%). The assessment of the anal sphincters in both ano-rectal manometry and anal en-dosonography in patients with IPAA enables structural and functional evaluation of the sphincters. The lack of high correlation be-tween these methods in our group of patients emphasizes the complexity of the many mechanisms that contribute to normal conti-nence. One of the examinations of anal sphincter function, besides clinical investiga-tion, is anal manometry, which showed normal function of the anal sphincters in most of our patients. Anal endosonography visu-alised defects of the IAS in 90% of the pa-tients. They might reflect the presence of sub-tle (not disturbing the function) changes of the sphincter, as a consequence of surgery, which in the future might predispose to further trauma (for instance obstetric), with the risk of anal incontinence development. Conclusions Ano-rectal monometry and anal endosonog-raphy are complementary methods in the as-sessment of the anal sphincters after IPAA. Although in our study manometry showed preserved function of the IAS in most of the cases, the abnormal image of this sphincter might be indicative of its subtle or imminent dysfunction. Dynamic anal endosonography supplements manometric evaluation of anal sphincters and enables prognosis of the sphincter function. Radiol Oncol 2003; 37(1): 17-22. 22 Sudoł-Szopińska I et al. / Endosonography and manometry of the anal sphincters References 1. Choen S, Tsunoda A, Nicholls RJ. 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