How Transvaginal Ultrasonography Can Help in the Indication of Surgical Treatment of Rectal Endometriosis

Abstract

Study Objective: The objective of this study is to analyze the accuracy of transvaginal ultrasonography (TVUS) to predict the distance between the lesion and the anal verge and the layers of the bowel compromised in cases of rectosigmoid endometriosis. Design: Prospective analysis of TVUS in cases of bowel endometriosis. Setting: Tertiary care Teaching Hospital. Patients: Between February 2005 and January 2007, 66 patients with deep endometriosis were submitted consecutively to TVUS and rectal endoscopic ultrasonography (REU). 58 were submitted to segmental resection of the rectum. Intervention: Transvaginal ultrassonography, rectal endoscopic ultrasonography and laparoscopic segmental resection of the rectum. Measurements and Main Results: REU findings were the reference standard to analyze the distance between the lesion and the anal verge. We also analyzed by TVUS, the deepest layer of the rectum compromised by endometriosis and we divided these patients into two groups: lesions infiltrating until the muscularis propria and lesions compromising submucosal or mucosal layer of the rectosigmoid, comparing with the pathologic findings. Considering the evaluation of the distance between the lesions and the anal verge, TVUS sensitivity, specificity, positive and negative predictive values were respectively 100%, 98.3%, 88.9% and 100%. Considering the evaluation of the rectal layer compromised by the lesions, all patients had histological confirmation of the disease in the rectum. The sensitivity, specificity, accuracy, positive and negative predictive values for TVUS to define that submucosal layer of the rectum compromised by endometriosis were 86.5%, 71.4%, 84.2%, 80.6% and 75% respectively. Conclusion: Transvaginal ultrasonography is an important tool to predict the distance between the lesion and the anal verge and the layers of the bowel compromised in cases of rectal endometriosis.