Background and objectives
Data on required excisions to achieve clear margins in pancreatic cancer are conflicting. Similarly, there are inconsistent protocols on aggressive lymphadenectomy. We review retropancreatic tissues, common metastatic lymph nodes and the mesopancreas with respect to pancreatic resection margins to improve our understanding of major sites for relapse that can be specifically targeted for effective treatments.
Materials and methods
This work is two-fold: keywords/phrases identified relevant publications on the mesopancreas and lymphadenectomy in PubMed databases; RCTs, original studies, prospective and retrospective studies were reviewed and results analysed.
Retropancreatic tissues including the mesopancreas are major sites for incomplete resections and relapse. Nomenclature for the mesopancreas is moot; nonetheless, its contents form a network of a neurolymphovascular-rich microenvironment that furnishes pathways for invasion and metastasis. The “mesopancreas” is a rectangular prism-shaped, primary micrometastasis site that overlaps with pancreatic resection margins and common metastatic lymph nodes. Most common infiltrated lymph nodes in 599 patients were stations 13, 17, 14, 12, 8, 16 and 6. Extended lymphadenectomy offers no survival benefit but promotes accurate staging.
A better understanding of the relationship between the anatomical position of the mesopancreas, common metastatic lymph nodes and the pancreatic circumferential resection margin offers important future applications for targeted treatment approaches to control tumour spread, stage nodal disease and reduce disease burden in retropancreatic tissues, frequently infiltrated lymph nodes and other anatomically complex sites such as the superior mesenteric neurovascular pedicle. Excision of common metastatic lymph node stations can improve outcomes.