Advance in the circumferential resection margin in pancreaticoduodenectomy for pancreatic head cancer

Resection margin involvement of pancreaticoduodenectomy is an key prognostic factor for pancreatic head cancer.However,there is a wide variation of reported microscopic margin involvement (R1) rate in the literature,and there is discrepancy between the R1 rate and clinical outcome.Recent studies indicate that the variation and the discrepancy are caused by confusing nomenclature,controversy regarding the difinition of R1,lack of standardization of pathological examination,and inaccurate diagnosis for the pancreatic head mass.This review summarizes the composition and nomenclature of the circumferential resection margin,the difinition of R1,the method of pathological examination,the relationship between R1 rate and prognosis,and the relationship between resection margin involvement and tumor origin. Key words: Pancreatic neoplasms; Pancreaticoduodenectomy; Pathology,surgical