Rectovesical ligament and fusion defect of the uterus with or without obstructed hemivagina and ipsilateral renal agenesis.

Objective: The rectovesical ligament is a peritoneal band in women with failure of fusion of the two Müllerian ducts. The aim was to evaluate existence of this abnormal structure in women with dysfused uterus and its possible relations to concomitant vaginal and renal anomalies.

Study Design: The study group comprised 47 women with uterine fusion defect (37 didelphic and 10 bicornuate uterus). They had undergone laparoscopy or laparotomy to visualize the pelvic cavity, and imaging for renal evaluation. The rectovesical ligament was present if inspection of the pelvic cavity revealed a broad peritoneal band between the two hemiuteri, attached anteriorly to the bladder and posteriorly to the sigmoid. Presence or absence of the ligament was reported, and concomitant renal and vaginal anomalies were evaluated.

Results: The rectovesical ligament was not visualized in 14 patients with didelphic or complete bicornuate uterus associated with unilateral renal agenesis: of these 13 had a previously treated obstructive longitudinal vaginal septum. A peritoneal band was found in 27 women with didelphic uterus with longitudinal vaginal septum with no obstruction and normal bilateral kidneys. Six women with bicornuate uterus had normal kidneys and an identified rectovesical ligament between the uterine hemicorpora, except for one with partial bicornuate uterus.

Conclusion: The rectovesical ligament is not merely a consequence of the failed fusion of two Müllerian ducts, but its relation to uterine malformation with or without vaginal and renal anomalies indicates some share of this structure in the early development of the urogenital system.