ANAL-SPHINCTER DEFECTS IN FECAL INCONTINENCE - CORRELATION BETWEEN ENDOSONOGRAPHY AND SURGERY

Background and Study Aims: Endoscopic ultrasound provides accurate inf ormation about the anatomy of the anal sphincter. The purposes of this study were to evaluate the use of flexible echo endoscopes to examine the anal sphincters, to validate the diagnosis of internal and extern al sphincter defects obtained using echo endoscopes by comparison with surgical findings, and to assess the outcome after surgical sphincter repair. Patients and Methods: Twenty-eight patients (13 women, 15 men , median age 50 years, range 30 - 83) with fecal incontinence - which was of traumatic origin in all but one (childbirth: n = 8; anorectal s urgery: n = 17; biopsy of the prostate: n = 2; no trauma: n = 1) - wer e prospectively investigated by endosonography using an echo colonosco pe (n = 14) or an echo gastroscope (n = 14) (CF-UM20, GF-UM20, Olympus Optical). The location and extent of the defects of the internal or e xternal sphincters, or both, were compared with the surgical findings in all patients. The surgical outcome was defined as excellent, improv ed, or unchanged. Results: At surgery, 25 of the 28 patients had an is olated internal sphincter defect (n = 15) or combined sphincter defect (n = 10). Endoscopic ultrasound identified all of the external anal s phincter defects (n = 10), and correctly excluded a defect in 15 of 18 patients (sensitivity, specificity, and accuracy 100%, 83% and 89%, r espectively). All of the internal sphincter defects (n = 25) were dete cted by endosonography. In three patients, a postulated intact interna l sphincter was confirmed by surgery (accuracy 100%). In two patients, the extent of the sphincter defect was underestimated. Despite good v isualization of the internal and external anal sphincters, as well as of the puborectal muscle in all patients, the shape, diameter, and ful l radial image sector (360 degrees) of the echo gastroscope made this instrument more practicable than the echo colonoscope. Nineteen of 25 patients who underwent surgery (76%) with proved sphincter defects exp erienced improvement, the figure reaching 87% (13 of 15) in patients w ho received isolated internal sphincter defect repair. Conclusions: An al endosonography, even using flexible echo endoscopes, is an accurate method for identifying anal sphincter defects, and is the method of c hoice for preoperative sphincter mapping with special regard to intern al sphincter repair, which can be carried out with excellent results.