OP15.04: Transvaginal elastography of rectosigmoid endometriotic nodules: correlation with symptoms and histology

To correlate the elastographic characteristics of rectosigmoid endometriotic nodules with symptoms and histology. This prospective study included patients with rectosigmoid endometriotic nodules scheduled for laparoscopic segmental colourectal resection. Patients under hormonal therapies in the 3 months prior to ultrasonography were excluded from the study. Ultrasonography was performed with a Voluson E6 machine. The elastograms were classified into 5 patterns according to the elasticity: from score 1 (low stiffness, the entire nodule is evenly shaded green) to score 5 (high stiffness, the entire nodule is evenly shaded blue). A questionnaire was used to assess gastrointestinal symptoms; a total gastrointestinal symptom score was calculated for each patient. The degree of fibrosis (rated from G0 to G4), the amount of endometrial stroma (from S1 to S4) and the disarray of muscle cells (from D0 to D3) were evaluated in a standardised fashion at histology. The study included 24 patients, their mean (±SD) age was 34.9 (±5.7) years. The mean largest diameter of nodules the was 29 (±7 mm); their mean volume was 8.4 (±5.9) cm3. The elasticity score was ≤3 in 7 patients, 4 in 8 patients and 5 in 9 patients. The elasticity score correlated with the intensity of dyschezia (Spearman's correlation coefficient = 0.836; p < 0.001) and with the gastrointestinal symptom score (Spearman's correlation coefficient = 0.716; p < 0.001). The elastographic stiffness of the nodules strongly correlated with the degree of fibrosis (Spearman's correlation coefficient = 0.798; p < 0.001) and negatively correlated with the amount of endometrial stroma (Spearman's correlation coefficient = −0.656; p < 0.001). There was a moderate correlation between the elastographic stiffness and the disarray of muscle cells (Spearman's correlation coefficient = 0.446; p = 0.029). Ultrasound elastography allows to predict the histological characteristics of the rectosigmoid endometriotic nodules and correlates with intestinal symptoms.