Safety of Mid and Low Rectal Cancer Surgery Without Dissection of the No.253 Lymph Node (S-M-O-O-T-H)

The range of the No.253 lymph node is as follows: medially, it extends from the root of the inferior mesenteric artery to the starting section of the left colonic artery; caudally, from the starting point of the left colonic artery to the intersection with the inferior mesenteric vein; laterally, it is bordered by the outer margin of the inferior mesenteric vein; and cranially, from the horizontal section of the duodenum to the beginning of the jejunum. In the controlled group, the surgery is performed with dissection of the No.253 lymph node.

In the experimental group, the surgery is performed without dissection of the No.253 lymph node.