Preoperative Imaging in Patients with Deep Infiltrating Endometriosis: An Important Aid in Predicting Depth of Infiltration in Rectosigmoid Disease

To determine the diagnostic accuracy of specialist-performed transvaginal ultrasound (TVUS) and pelvic magnetic resonance imaging (MRI) modalities in predicting depth of deep infiltrating endometriosis (DIE) of the rectosigmoid by comparison with histologic specimens obtained at surgery.A retrospective analysis, which met the Standards for Reporting of Diagnostic Accuracy Studies (2015) guidelines for a diagnostic accuracy study.Tertiary teaching hospital.A total of 194 cases who underwent preoperative discussion at the gynecologic endosurgery unit multidisciplinary meeting between January 2012 and December 2019 were eligible for inclusion.Retrospective assessment of the accuracy of TVUS and MRI in predicting histologic depth of rectosigmoid DIE after operative management.Al total of 135 surgeries were performed for DIE; 20 underwent a rectal shave, 14 had a disc/wedge resection, 38 an anterior/segmental resection, and 63 had no rectosigmoid surgery. Of the 52 patients with full-thickness rectal wall excision, all patients had at least one imaging modality available for review; 42 (81%) had both. At least one imaging modality was in agreement with histologic depth in 48 cases (92%) (sensitivity, 94%; specificity, 50%; positive predictive value [PPV], 97.9%; negative predictive value [NPV], 25.0%; area under the receiver operating curve, 0.720; 95% confidence interval, 0.229-1.000). When TVUS was assessed in isolation, the test remained sensitive for any rectal wall involvement (sensitivity, 93.6%; specificity, 50.0%; PPV, 97.8%; NPV, 25.0%; area under the receiver operating curve, 0.718; 95% confidence interval, 0.227-1.000). When only MRI was assessed, the test demonstrated both high sensitivity and specificity for rectal wall disease (sensitivity, 86.4%; specificity, 100%; PPV, 100%; NPV, 14.2).Specialist-performed TVUS and MRI are accurate in predicting depth of disease in rectosigmoid endometriosis. These modalities were similar in their diagnostic performance at assessing depth of rectal wall involvement, and their use is justified in the preoperative planning of these gynecologic surgeries.