Does previous surgery influence the asymmetric distribution of endometriotic lesions?

Our objective was to investigate the role of previous abdominal-pelvic surgery in the asymmetric distribution of pelvic endometriosic lesions. This was a retrospective study carried out at the Clinic of Obstetrics and Gynecology, University of Ancona, Italy, and included 238 patients with histological confirmation of endometriosis. The interventions were surgical treatment, at laparoscopy or laparotomy, for pelvic pain and endometriosis. The main outcome measure(s) were endometriotic lesions and adhesions in the pelvis found during surgery and the dinical records of the patients. We found unilateral lesions in 149 patients (62.6%): the right side of the pelvis affected in 55 patients (36.9%) and the left side in 94 patients (63.1%) (p < 0.01). In the group of patients who had undergone previous abdominal surgery, we found lesions on the right side in 26 cases (32.5%), and on the left in 54 cases (67.5%) (p < 0.01). We found that the patients who had undergone previous abdominal surgery had significantly more adhesions than those with no previous surgery (80/116 vs. 73/122, p = 0. 002). As a new finding, we have demonstrated that the left side of asymmetric distribution of intrapelvic macroscopic lesions is preserved and more evident in patients with previous abdominal surgery, including previous appendectomy. These data seem to be in agreement with our previous supposition of a possible interaction between previous abdominal surgery and the mechanisms of endometriosis development.