Normal and abnormal pelviscopic anatomy at the internal inguinal ring in boys and the vasal triangle

Structure and functional significance of the transverse vesical fold

The plica vesicalis transversa or transverse vesical fold (TVF) is a peritoneal fold extending from the lateral side of the bladder to the side of the lesser pelvis near the deep inguinal ring. It is an important landmark in laparoscopic surgery of the pelvis but is variably observed in the embalmed cadaver. We investigated the gross anatomy of this structure in the cadaver and confirmed that its medial portion corresponds to the location of the superior vesical artery(ies), thus supporting the idea that the TVF is "mesovesical." However, no large vessels were observed grossly in the lateral portion of the TVF. The hypothesis that the lateral TVF has a suspensory function was tested histologically by comparison with the suspensory ligament of the duodenum and the phrenicocolic ligament, both of which have smooth muscle contributing to their inferred suspensory function. Microscopic examination of prepared samples from 20 cadavers shows that the TVF evinces no smooth muscle in either its lateral or medial segments. The TVF is demonstrated to be a mesentery-like reflection of peritoneum raised by branches of the superior vesical artery which provides no demonstrable structural support for the bladder. Implications of these findings include avoidance of sectioning of medial TVF during laparoscopic surgery because of its vascular nature, and inadvisability of utilizing any portion of theTVF for an anchor in reconstruction of the anterior pelvic floor within the paravesical fossae.