OC22.04: Transvaginal ultrasonography combined with computed tomographic colonography in the diagnosis of bowel endometriosis

To assess the accuracy of transvaginal ultrasonography (TVS) combined with computed tomographic colonography (CTC) in the diagnosis of bowel endometriosis. This prospective study included patients of reproductive age with clinical suspicion of bowel endometriosis. Patients underwent TVS and CTC within 3 months before laparoscopic excision of endometriosis. In case of disagreement between TVS and CTC, the sonographer and the radiologist evaluated the exams in a joined session in order to provide a final result of the two exams (TVS-CTC). Findings of TVS-CTC were compared with surgery and histology. 170 women were included in the study; 89 (52.4%) had bowel endometriosis. The largest endometriotic nodule was located on the upper rectum in 21 patients, on the rectosigmoid in 31 patients, on the low rectum in 29 patients, on the caecum in 6 patients and on the ileum in 2 patients. The diagnostic performance of TVS-CTC in the diagnosis of bowel endometriosis was: sensitivity 95.5% (88.9%–98.8%); specificity 96.3% (89.6%–99.2%); positive likelihood ratio 25.79 (8.49–78.35), negative likelihood ratio 0.05 (0.02–0.12); positive predictive value 96.6% (90.3%–98.9%), negative predictive value 95.1% (88.2%–98.1%). At histological examination, multifocal disease was found in 13 patients with bowel endometriosis (14.6%); multifocal disease was diagnosed by TVS-CTC in 11 patients (84,6%). Multicentric disease was observed in 7 patients (7.9%), 6 (85.7%) of these nodules were diagnosed by TVS-CTC. No adverse events occurred during the exams and no patient required interrupting RWC-TVS or CTC. The intensity of pain perceived during CTC was higher than the intensity of pain perceived during TVS (p<0.001). RWC-CTC has high performance in diagnosing not only rectosigmoid endometriosis but also other lesions (such as those located on the caecum and last ileal loops). This technique also allows diagnosing multifocal and multicentric disease.