ABSTRACT
According to multicenter randomized controlled trials, laparoscopic radical resection of colon cancer has the same short and long term clinical efficacy as traditional open surgery. In laparoscopic radical resection of right semicolon cancer, it is important to separate the embryonic plane of the root, and to ligate and cut off the central vascular roots. Only by separation along the membrane space can one achieve minimally invasive operation with no bleeding, and ensure the integrity of the excision of the mesangium and avoid damage of internal fascia and other organs. The mesangial distribution of the right semicolon is adjacent to the mesangium of the stomach and is connected to the mesentery of the small intestine. The pancreaticoduodenum locates between the right semicolon mesentery and the retroperitoneal subperitoneal fascia. In particular, the relationship between the anterior and posterior Treitz fascia of the pancreaticoduodenum and the Toldt space is complex, which is closely related to the feasibility of complete mesocolic excision(CME). This article introduces the distribution of intermembranous space and mesangial bed in the right semicolon, presenting the problem in CME surgery. In addition, there are key points in identifying the gap between the membranes based on the author’s experience and we propose a new evaluation criteria for membrane surgical specimens, which has certain guiding significance for radical CME surgery for right semicolon cancer.