Endorectal ultrasonography in predicting rectal wall infiltration in patients with deep pelvic endometriosis:: A modern tool for an ancient disease

PURPOSE: This study evaluated the validity of endorectal ultrasonography in predicting rectal infiltration in patients with deep pelvic endometriosis. METHODS: Patients were recruited consecutively in the Department of Surgical Gynecology of Diaconesses Hospital from April 1996 to July 2003. Inclusion criteria were the suspicion of deep pelvic endometriosis on the basis of outpatient history and/or clinical symptoms with a mass palpable on bimanual examination that might infiltrate the rectal wall. There were no exclusion criteria. Endorectal ultrasonography wasperformed by the same investigator with a 7.5-MHz to 10-MHz rigid probe, producing a 360 degrees view of the rectal wall and adjacent areas. We used surgical and histopathologic findings as the "gold standard" to evaluate the validity of endorectal ultrasonography. RESULTS: This study was based on 37 patients (mean age, 35.8 (range, 26-46) years) who underwent surgery. The time between endorectal ultrasonography and surgery ranged from 4 to 529 (mean, 88.7) days. Eight patients had endometriosis nodules penetrating the rectal wall. Endorectal ultrasonography showed sensitivity, specificity, a positive predictive value, and a negative predictive value of 87.5, 97, 87.5, and 97 percent, respectively, in the diagnosis of infiltration of the rectal wall by endometriosis. CONCLUSIONS: Endorectal ultrasonography is a reliable technique for visualizing rectal infiltration in patients with deep pelvic endometriosis. It should be more widely used by gynecologists because knowing about rectal infiltration before surgery is fundamental to defining the best possible surgical approach.