# Unraveling the Pancreatic Anlagen: Validating a Manual Dissection Protocol with Immunohistochemical Staining for Pancreatic Polypeptide in a Human Cadaver Study

## TL;DR

This study shows that the adult pancreas can be divided into embryological compartments using a manual dissection method and staining for pancreatic polypeptide, which could improve surgical precision.

## Contribution

A validated manual dissection protocol using immunohistochemical staining for pancreatic polypeptide to separate the pancreas into embryological compartments.

## Key findings

- Landmark-guided dissection successfully separated the pancreas into morphogenetic compartments in seven out of ten cases.
- Immunohistochemical staining for pancreatic polypeptide effectively differentiated tissue origins along the dissection plane.
- Two cases showed deviations from the dissection plane, with one case affected by tumor tissue.

## Abstract

Background: The pancreas develops from two independent buds that fuse to form the adult organ. Ontogeny has largely been neglected in pancreatic surgery. This study aims to demonstrate that the adult pancreas can still be divided into morphogenetic units based on its embryological compartments and connective tissue borders for potential therapeutic purposes. Methods: Ten donor bodies (four female, six male, aged 73–101 years) were used. Manual dissection, guided by the common bile duct to locate the embryological fusion plane, was performed to divide the pancreatic tissue. Immunohistochemical staining for pancreatic polypeptide differentiated the pancreatic tissue by embryological origin and was used to quantify dissection accuracy. Results: Landmark-guided dissection successfully separated the pancreas along a connective tissue plane in seven cases. The resulting compartments were distinctly divided along the dissection plane into an area rich in pancreatic polypeptide and an area with low accumulation. Two cases showed deviations from the dissection plane at the histological level. One case contained tumor tissue, interfering with the utilization of landmarks. Conclusions: Landmark-guided dissection of the pancreas based on its embryological fusion plane allows for reliable separation into morphogenetic compartments. Immunohistochemical staining for pancreatic polypeptide effectively differentiates tissue origins. This approach may enable more precise, differentiated pancreatic resections and tailored treatments, with potential for refinement in routine surgical practice. Approaching the pancreatic tissue with regard to its ontogenetic origin and its clearly distinguishable compartments might even enable tailored treatment beyond refined surgical procedures.