The Toldt fascia: A historic review and surgical implications in complete mesocolic excision for colon cancer.

To clarify the anatomic concept of Toldt fascia, based on the literature review and the surgical anatomic dissection using laparoscopic or robotic approach. We undertook review of the historic literature and surgical videos from 250 patients with colorectal cancer operated on laparoscopically or robotically to discuss the surgical implications of Toldt fascia in complete mesocolic excision for colon cancer. Toldt fascia, sandwiched by the overlying mesothelial layer of the mesocolon and underlying mesothelial layer of the retroperitoneum, comprised loose fibrous tissues with minute vessels inside, and was contiguous from the ileocecal mesentery radix to the upper rectum. Surgical dissection plane is readily developed within the Toldt fascia; however, any attempt to dissect along the interface between Toldt fascia and the overlying mesocolon or underlying retroperitoneum failed. Within the anatomic territory of kidney, Toldt fascia fused with Gerota fascia, and then extended in all directions: upward to the dosal surface of the duodenum, liver and pancreas; medially to fuse with the adventitia layer of the abdominal aorta; laterally, it tapered at the area below the reflection of visceral and parietal peritoneum; and downward, it became a thin membranous structure covering the gonadal vessels, ureters and retroperitoneal structures and ended at the upper rectum, where it met the junction of endopelvic fascia and proper fascia of the rectum. The present study demonstrated that Toldt fascia is a natural embryonic dissection plane for the precise conduction of complete mesocolic excision for colon cancer.