Is training sufficient for ultrasound operators to diagnose deep infiltrating endometriosis and bowel involvement by transvaginal ultrasound?

OBJECTIVES: To assess and compare the diagnostic accuracy of transvaginal ultrasonography (TVUS) by trained or untrained ultrasound operators in deep infiltrating endometriosis (DIE) imaging, for diagnosing DIE and bowel involvement.

METHODS: This was an observational study of patients with clinically suspected DIE operated in a reference center. TVUS was performed pre-operatively by a trained or/and untrained ultrasound operator to search for DIE and rectal involvement. During surgery, DIE was diagnosed according to macroscopic and histological criteria. Sensitivity (Se), specificity (Sp) and c-index were calculated with 95% confidence intervals for trained and untrained operators, if TVUS results were significantly predictive of DIE and rectal involvement at p<0.05.

RESULTS: 115 patients were included: 100 (87%) had DIE and 34 (29.6%) had bowel involvement. TVUS was performed by a trained ultrasound operator for 70 patients and by an untrained one for 56 patients. When performed by a trained operator, TVUS significantly predicted DIE with a Se of 58% (95% CI, 46-70), a Sp of 87.5% (95% CI, 63-100) and a c-index of 0.73 (95% CI, 0.59-0.87). TVUS performed by an untrained operator was not significantly predictive of DIE (p=0.58). Rectal involvement was significantly predicted by TVUS performed by a trained operator with a Se of 40% (95% CI, 23-59), a Sp of 93% (95% CI, 86-100) and a c-index of 0.67 (95% CI, 0.56-0.77). None of the untrained ultrasound operators diagnosed a bowel involvement.

CONCLUSION: TVUS is not sufficient to diagnose DIE and bowel involvement, in particular when performed by untrained ultrasound operators.