Endoanal MR Imaging of the Anal Sphincter in Fecal Incontinence1
Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands.Radiographics (Impact Factor: 2.6). 11/1999; 19 Spec No(suppl_1):S171-7. DOI: 10.1148/radiographics.19.suppl_1.g99oc02s171
Fecal incontinence is a major medical and social problem. The most frequent cause is a pathologic condition of the anal sphincter. Endoanal magnetic resonance (MR) imaging allows detailed visualization of the normal anatomy and pathologic conditions of the anal sphincter. The hyperintense internal sphincter appears as a continuation of the smooth muscle of the rectum; the hypointense external sphincter surrounds the lower part of the internal sphincter. A sphincteric defect is seen as a discontinuity of the muscle ring. Scarring appears as a hypointense deformation of the normal pattern of the muscle layer. Two external sphincteric patterns may be misdiagnosed as defects: a posterior discontinuity (often seen in young male patients) and an anterior discontinuity (often seen in female patients). Atrophy of the external sphincter is easily detected on coronal MR images by comparing the thicknesses of all anal muscles. Endoanal MR imaging is superior to endoanal ultrasonography because of the multiplanar capability and higher inherent contrast resolution of the former. Use of endoanal MR imaging may lead to better selection of candidates for surgery and therefore better surgical results. Endoanal MR imaging is the most accurate technique for detection and characterization of sphincteric lesions and planning of optimal therapy.
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ABSTRACT: Anal function depends on the integrity and quality of the sphincter muscles. The diagnosis of external anal sphincter atrophy on endocoil magnetic resonography has been associated with poor outcome from sphincter repair, although the imaging criteria for atrophy remain unclear. Women with intact sphincters on endosonography and either normal (more than 60 cm H(2)O) (n = 9) or low (n = 16) squeeze pressures had endocoil magnetic resonography and electromyography. The area and fat content of the external anal sphincter and puborectalis were measured on mid-coronal magnetic resonography and images were graded as showing normal, intermediate or advanced atrophy. The definition of the external anal sphincter on endosonography and the thickness of the internal anal sphincter were also assessed. Women with a normal anal squeeze pressure had a larger external anal sphincter cross-sectional area (mean(s.d.) 240(56) versus 193(62) mm(2); P = 0.01) with a lower mean fat content (mean(s.d.) 23(4) versus 30(6) per cent; P < 0.001) than those with low squeeze pressures. There was an overall correlation between squeeze pressure, cross-sectional area (r = 0.32, P = 0.02) and fat content (r = - 0.51, P < 0.001). Patients with a thin (less than 2 mm) internal anal sphincter and/or a poorly defined external sphincter on endosonography were more likely to have atrophy (positive predictive value 74 per cent). : Potential endosonographic markers for external anal sphincter atrophy are suggested, and a visual scale for endocoil magnetic resonographic assessment has been validated.British Journal of Surgery 06/2001; 88(6):853-9. DOI:10.1046/j.0007-1323.2001.01796.x · 5.54 Impact Factor
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ABSTRACT: To determine the incidence and functional consequences of external sphincter trauma compared with other perineal structures using a novel imaging technique, three-dimensional endosonography. Fifty-five nulliparous women (mean age 30 years, range 18--47 years) had three-dimensional anal endosonography, anal manometry, and questionnaire assessment of continence at a median gestation of 33 weeks (23--42 weeks) and 10 weeks (7--22 weeks) after delivery. There was ultrasound evidence of postpartum trauma in 13 of 45 women who had a vaginal delivery (29%, confidence interval [CI] 16%, 44%), involving the external sphincter in five (11%, CI 4%, 24%), the puboanalis in nine (20%, CI 10%, 35%), and the transverse perineii in three (7%, CI 1%, 18%). In four, more than one structure was damaged. External sphincter trauma was associated with a significant decrease in squeeze pressure (P =.035) and an increase in incontinence score (P =.02) compared with those without trauma. Tears to the puboanalis or transverse perineii only did not affect pressure or incontinence scores. Coronal imaging of the external anal sphincter was a useful adjunct to the assessment of trauma. The overall incidence of trauma to the sphincter complex was similar to that of previous reports, although actual damage to the external sphincter was less common and represented the only functionally significant component.Obstetrics and Gynecology 06/2001; 97(5 Pt 1):770-5. DOI:10.1016/S0029-7844(01)01318-7 · 5.18 Impact Factor
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ABSTRACT: The aim of this study was to examine the clinical results after anterior anal sphincter repair in patients with obstetric trauma and to evaluate possible risk factors for poor outcome. In years 1990-99 anterior anal sphincter repair for anal incontinence due to obstetric trauma was performed in 39 patients at Helsinki University Central Hospital. Clinical examination with Parks' classification and patients' questionnaire with endoanal ultrasound (EAUS) were done before and after surgery. Pudendal nerve terminal motor latency (PNTML) was measured postoperatively. The median follow-up time after the operation was 22 months (range 2-99). The follow-up results of the patients' questionnaire for 12 patients (31%) were good, for 15 patients (38%) acceptable and for 12 patients (31%) poor. Postoperative EAUS showed sphincter overlap in 28 (72%) patients but a defect was still found in 11 (28%) patients. A defect found on postoperative EAUS correlated with poor clinical result according to Parks' (R = 0.8, P < 0.01) and patients' questionnaire results (R = 0.7, P < 0.01). Patients with poor clinical results (Parks III/IV) were statistically significantly older (median 63 years, range 26-73) than those with favourable results (Parks I/II) (median 45 years, range 27-79) (P < 0.05). Further, the duration of incontinence symptoms correlated with poor functional results (R=0.4, P < 0.05). After obstetric trauma anterior anal repair gives acceptable short-term clinical results. EAUS investigation is easy and harmless to perform and should be used pre- and post-operatively. Advanced age, pre-operative signs of perineal descent, long-lasting severe incontinence symptoms and a persistent defect on postoperative EAUS seem to be related to poor clinical result.Colorectal Disease 01/2003; 5(1):73-8. DOI:10.1046/j.1463-1318.2003.00408.x · 2.35 Impact Factor
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