Marvin Heimke

Aim Right hemicolectomy with complete mesocolic excision (CME) requires the removal of an intact mesocolic envelope. The study aimed to determine, on the basis of macroscopic and microscopic anatomical studies, the optimal surgical dissection planes for CME to preserve fascial integrity. Unequivocal anatomical nomenclature was applied to describe the retrocolic fascial system and compared to frequently used eponyms (Toldt, Gerota, Fredet, Treitz). Method Stepwise macroscopic dissections, cross‐section studies and histological analysis were performed on body donors to identify the components of the retrocolic fascial system. Based on these anatomical findings, the optimal surgical dissection planes for CME were validated in laparoscopic training courses on body donors and in robot‐assisted surgical procedures in patients. Results The mesocolic tissue and lymphovascular pedicles were enveloped by the ventral and dorsal mesocolic leaf (mesocolic fascia). The mesocolic fascia was attached to the parietal peritoneal fascia (‘fascia of Toldt’) along the parieto–mesocolic interface, and further cranially to the pre‐duodenopancreatic fascia along the mesocolic–duodenopancreatic interface (‘space of Fredet’). Dorsally, the parietal peritoneal fascia was separated from the anterior renal fascia (‘fascia of Gerota’) by the parieto–renal interface. Dissection along this interface in front of the anterior renal fascia followed by incision of the parietal peritoneal fascia at the duodenal border and opening the mesocolic–duodenopancreatic interface yielded the best macroscopic appearance of specimens and was considered optimal for CME. Conclusion The retrocolic fascial system as well as the surgical dissection planes for CME can be described by clearly defined anatomical terms rather than potentially confusing eponyms.