ANAL-SPHINCTER DEFECTS - CORRELATION BETWEEN ENDOANAL ULTRASOUND AND SURGERY

Objective This study was performed to (1) correlate anal sphincter def ects, identified by endoanal ultrasound with operative findings, and ( 2) define the appearance of such sphincter defects as seen at operatio n. Summary Background Data Endoanal ultrasonography is a minimally inv asive method of imaging the anal sphincter complex and enables identif ication of anal sphincter defects. Little is known about the accuracy and limitations of endoanal ultrasound in identifying such defects. Fu rthermore, there are no data about the appearances of these endosonic sphincter defects as seen at operation. Methods Forty-four patients (4 0 women; age range, 26 to 80 years, mean age, 56 years) with fecal inc ontinence, undergoing pelvic floor repair, were investigated by endoan al ultrasound before operation. Endosonic findings were correlated wit h the appearances of external anal sphincter, internal anal sphincter, and intersphincteric space, at operation. Diagnosis of the site and t ype of defect was made by macroscopic appearances. Uncertainty about t he 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 inter nal sphincter defects identified by endosonography also were confirmed at operation. In ten patients with a neuropathic anal sphincter compl ex, the morphology was, normal on endosonography, and this was confirm ed at operation. (Sensitivity and specificity of 100% for external ana l sphincter; 100% and 95.5%, respectively, for internal anal sphincter ) Conclusions These data show that endoanal ultrasound is an accurate method of identifying anal sphincter defects.