Reappraisal of the Vascular Anatomy of the Colon and Consequences for the Definition of Surgical Resection

Introduction: Databases of information on surgical treatment for colorectal cancer have been created in various countries and data have started to be released. The most important facets of research for statistical processing include the methodology and firm definitions of content. However, for trials involving colorectal cancer, the applicable terminology has not been defined, and much bias is frequently encountered. Starting from definitions of the colon and vascular system of the colon, we propose definitions of surgical procedures for colorectal cancer. Methodology: This paper reviews the colon segments and vascular anatomy of the colon. If surgical treatment of colon cancer is considered from this perspective, we can see that definitions for these surgical procedures are lacking. The definition of surgical treatment would also allow clarification of the range of lymph node dissection. In general, surgical procedures and the area of surgical lymph node dissection are both defined according to the basic structure of the associated arteries. However, the existing descriptions are not based on a definition of the arteries. We therefore tried to establish the most useful nomenclature for the arterial system of the large intestine for colorectal surgeons and reviewed the frequency of important arterial variations. Using the resulting definitions, we provided consistent definitions for colon cancer surgery. Conclusion: The segments of the colon need to be defined. In surgery, procedures are performed using the arteries as indicators, so vessels originating from the superior and inferior mesenteric arteries are referred to as arteries, with others are referred to as branches. Surgical treatment of colon cancer can be defined from the relationship between these arteries. For the first time, this may allow proper application of statistics for the treatment of colon cancer.