Diagnostic accuracy of transvaginal sonography (TVS) for non-invasive diagnosis of rectosigmoidal endometriosis – a systematic review and meta-analysis

The aim of this study was to critically analyze the diagnostic value of TVS for non-invasive, presurgical detection of bowel endometriosis.

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

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 14% to 73.3%. Positive LHR's ranged from 4.8 to 48.56, negative LHR's ranged from 0.02 to 0.75 with wide confidence intervals (CI's). Pooled estimates of sensitivities and specificities were 91% and 98%; PPVs and NPVs 98% and 95%; positive and negative LHR's 30.36 and 0.09, 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 (RWC-TVS) versus no prior bowel enema (TVS). The negative LHR was 0.04 for RWC-TVS versus 0.47 for TVS.

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.