The retropancreatic fusion fascia acts as a barrier against infiltration by pancreatic carcinoma.

Although pancreatic carcinoma frequently extends posteriorly beyond the pancreatic parenchyma, retroperitoneal organs such as the inferior vena cava (IVC) and the adrenal gland are rarely involved. The fusion fascia lies between the pancreas and these retroperitoneal organs. This study investigated the role of the fusion fascia in the prevention of infiltration of retroperitoneal structures by pancreatic carcinoma. This study was conducted on 140 patients who underwent pancreatic carcinoma resection at our hospital. Retropancreatic infiltration was divided into three grades as follows: Grade 0, carcinoma confined within the pancreatic parenchyma; grade 1, carcinoma infiltrating beyond the parenchyma but within the fusion fascia; and grade 2, infiltration of retroperitoneal tissues beyond the fusion fascia. Grade 0 was found in 24%, grade 1 in 73% and grade 2 in 3% of the cases. There was no significant difference in the prevalence of grade 2 between pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Pancreatic carcinoma infiltrated posteriorly beyond the parenchyma in over 70% of our cases; however, grade 2 infiltration was a rare finding and tumor invasion was confined within the fusion fascia in almost all the cases. Thus, the fusion fascia may act as a barrier against retroperitoneal tissue infiltration by pancreatic carcinoma.