Exploration of peripancreatic lymphatic pathways in a live porcine model

Abstract

Pancreatic cancer is associated with a poor prognosis, mainly due to lymph node invasion and lymph node recurrence after surgical resection, even after extended lymphadenectomy. The peripancreatic lymphatic system is highly complex and the specific lymphatic drainage of each part of the pancreas has not been established. The aim of this study was to determine the lymphatic drainage pathways specific to each part of the pancreas on live pigs using Patent Blue. The pancreases of 14 live pigs were injected in different parts of the gland. The technique was efficient and reproducible. The diffusion patterns were similar for each location and were reported. Our results in pigs allowed us to define specific nodal relay stations and lymphatic drainage for each part of the pancreas and confirm that independent anatomical-surgical pancreatic segments can be described. It is interesting to note that lymphatic drainage for the upper part of the proximal part of pancreas (duodenal lobe) occurred on the left side of the portal vein. This suggests that lymph node resection during cephalic duodenopancreatectomy in humans should be extended to the left side of the mesenteric vein, and probably to the right side of the superior mesenteric artery, as recently suggested. These results could help surgeons perform safe anatomical-segmental pancreatic resections with accurate lymphadenectomies and improve survival in patients with pancreatic cancer. Based on these results we will perform an innovative prospective study. Patent Blue will be injected into different parts of the gland in patients operated for pancreatic resection, and lymphatic diffusion of the dye will be recorded in relation to their origin from the theoretical pancreatic segments (ClinicalTrials.gov Identifier: NCT03597230).

Keywords: Lymphatic capillaries; Pancreas; Pancreatic neoplasms/surgery; Pancreatic segmental transplantation; Pancreatic segments.