OC01.02: How to estimate the degree of bowel stenosis in patients with colorectal endometriosis?

To compare the precision of different imaging techniques in estimating the degree of stenosis of the bowel lumen in patients with colorectal endometriosis. This prospective study included 43 patients with rectosigmoid endometriosis who underwent segmental bowel resection. Before surgery, the percentage of bowel stenosis was estimated by the following exams: transvaginal ultrasonography (TVS), rectal water contrast transvaginal ultrasonography (RWC-TVS), magnetic resonance enema (MRI-e) and computed tomographic colonography (CTC). The physicians who performed the exams were blinded to the results of the other imaging techniques. After surgery, the specimens were sent to the pathologist. Areas of interest were marked with suture threads. Large bowel specimens were stuffed with 10% buffered formalin-soaked paper rolls to maintain the anatomic integrity and to reduce shrinkage artefacts; they were then routinely fixed for 12–18 hours. Selected areas were sectioned transversally, embedded in paraffin maintaining the anatomic shape and cut with the microtome to obtain 3 μM thick whole-mount sections of the large bowel. Measures were obtained using a microscope eyepiece reticule. Imaging findings and results of pathologic examination were compared. At pathology, the mean (±SD) length of the ressected bowel stenosis was 10.9 (±1.9) cm; the mean (±SD) largest diameter of the largest nodule was 34.2 (±5.9) mm; the mean (±SD) volume of the largest nodule was 10.6 (±5.8) cm3. The mean (±SD) degree of the stenosis of the bowel lumen was 64.1% (±15.6%). The Kruskal-Wallis one-way analysis of variance on ranks showed that the imaging techniques had different precision in estimating the degree of bowel stenosis (p<0.001). The Tukey test showed that CTC was more precise than other techniques in estimating the degree of bowel stenosis (p<0.05); MRI-e was more precise than TVS (p<0.05). CTC is more precise than TVS, RWC-TVS and MRI-e in estimating the degree of stenosis of the bowel lumen in patients with colorectal endometriosis.