Anatomic study on protection of left ureter in total mesorectal excision

Objective To discuss the anatomical structure and protection method of the left ureter in total mesorectal excision(TME).Methods 40 human corpses preserved or fixed with 10% formalin were randomly selected and underwent the total mesorectal excision(TME),to observe the path of ureter and its adjacent structures.The distance from abdominal aortic bifurcation to the sacral promontory and the inferior mesenteric artery root was measured,as well as the distance from the point the left ureter crossing over the common iliac artery to the abdominal aortic bifurcation and the left internal ring.Results The left ureter ran medially and was close to the left sigmoid mesocolon.The left ureter crossing over the common iliac artery was located roughly 1/3 of the abdominal aortic bifurcation to the left internal ring.The basin segment of left ureter ran behind presacral fasciae of the pelvic sidewall and was located anterolaterally to the lateral ligament of the rectum.Mesorectum was in front of the presacral fascia and at different anatomical spaces from the ureter.Conclusions Injury of the ureter can be effectively avoided only when we understand the anatomical plane completely and use the anatomic landmarks such as sacral promontory,iliac vessels,internal ring and the abdominal aortic bifurcation to position the ureter accurately.