Retrocolic spaces: anatomy of the surgical planes in laparoscopic right hemicolectomy for cancer.

To explore the regional anatomy of the fasciae and spaces around the right-side colon from laparoscopic perspective, we observed the location, extension, and boundaries of the spaces around the right-side colon in seven cadavers and in 49 patients undergoing laparoscopic right hemicolectomy for cancer, and reviewed computed tomography images from patients and healthy individuals. Between the ascending mesocolon and prerenal fascia (PRF), there was a right retrocolic space (RRCS), which extended in all directions. The anterior, posterior, medial, lateral, cranial, and caudal boundaries of the RRCS were the ascending mesocolon, PRF, superior mesenteric vein, right paracolic sulcus, inferior margin of the duodenum, and inferior margin of the mesentery radix, respectively. Between the transverse mesocolon and the pancreas and duodenum, there was a transverse retrocolic space, which was enclosed cranially by the radix of the transverse mesocolon. In CT images, healthy PRF was noted as slender line of middle density, continuing to the transverse fascia. The retrocolic spaces was unidentifiable, unless they were filled with retroperitoneal lesions. The RRCS and transverse retrocolic space are natural surgical planes for laparoscopic right hemicolectomy for cancer. The boundaries of these fusion fascial spaces are the best access, and the PRF is the best guide.