Diagnostic accuracy of transvaginal ultrasound for non-invasive diagnosis of bowel endometriosis: systematic review and meta-analysis.

OBJECTIVE: To critically analyze the diagnostic value of transvaginal sonography (TVS) for non-invasive, presurgical detection of bowel endometriosis.

METHODS: MEDLINE (1966-2010) and EMBASE (1980-2010) databases were searched for relevant studies investigating the diagnostic accuracy of TVS for diagnosing deep infiltrating endometriosis involving the bowel. Diagnosis was established by laparoscopy and/or histopathological analysis. Likelihood ratios (LRs) were recalculated in addition to traditional measures of effectiveness.

RESULTS: Out of 188 papers, a total of 10 studies fulfilled predefined inclusion criteria involving 1106 patients with suspected endometriosis. The prevalence of bowel endometriosis varied from 24 to 73.3%. LR+ ranged from 4.8 to 48.56 and LR- ranged from 0.02 to 0.36, with wide confidence intervals. Pooled estimates of sensitivities and specificities were 91 and 98%; LR+ and LR- were 30.36 and 0.09; and positive and negative predictive values were 98 and 95%, respectively. Three of the studies used bowel preparations to enhance the visibility of the rectal wall; one study directly compared the use of water contrast vs. no prior bowel enema, for which the LR- was 0.04 and 0.47, respectively.

CONCLUSIONS: TVS with or without the use of prior bowel preparation is an accurate test for non-invasive, presurgical detection of deep infiltrating endometriosis of the rectosigmoid.