Bowel Preparation Improves the Accuracy of Transvaginal Ultrasound in the Diagnosis of Rectosigmoid Deep Infiltrating Endometriosis: A Prospective Study

Abstract

Study objective: To compare the accuracy of transvaginal ultrasound (TVUS) with and without bowel preparation (BP) to detect and describe intestinal nodules of deep infiltrating endometriosis (DIE) with laparoscopic findings.

Design: A prospective study of paired data (Canadian Task Force classification II.1).

Setting: A tertiary university hospital from November 2014 to November 2015.

Patients: A cohort of women awaiting surgery for endometriosis.

Interventions: The wall of the rectum and the lower sigmoid colon of the patients were evaluated by 2 TVUSs: the first ultrasound was performed without previous BP, and the second was done after a 3-day low-residue diet and two 250-mL enemas 12 hours and 3 hours before TVUS.

Measurements and main results: The presence or absence of rectosigmoid nodules visualized by TVUS with and without BP was compared with laparoscopic results. Forty patients with a mean age of 36.8 ± 5.0 years were included in the study. By comparing the surgical findings histologically confirmed (the presence or absence of bowel nodules and localization) with those of the 2 TVUSs with and without BP, the sensitivity, specificity, and Cohen kappa were 100%, 96%, and 0.95 and 73%, 88%, and 0.61, respectively. Laparoscopy showed that up to 37.5% of patients (15/40) presented bowel involvement. Variables were clearly more evaluable with than without BP.

Conclusion: TVUS with BP has a higher accuracy than TVUS without BP. BP allows and facilitates the detection of more rectal nodules of DIE in patients with suspected endometriosis and surgical criteria.

Keywords: Bowel endometriosis; Bowel preparation; Deep infiltrating endometriosis; Pelvic pain; Transvaginal ultrasound.