HP12 THE ANATOMICAL BASIS OF THE SURGICAL TREATMENT OF GASTRO‐OESOPHAGEAL REFLUX: LESSONS FROM HISTORY AND SIMULATION

Purpose  To review the anatomical basis for anti-reflux operations and describe a project designed to develop a 3D micro-anatomical model of the gastro-oesophageal junction with integrated physiological events. Methodology and Results  A realistic 3D anatomically based computer model of the gastro-oesophageal junction (GOJ) was constructed using cross-sectional digital images from the Visible Human Project. A finite element mesh was constructed and an iterative fitting process provided smooth surfaces. For accurate simulation of physiologic function it is necessary to augment this geometric model with detailed micro-structural information. A custom-built, semi-automated, extended-volume imaging system was used to obtain images of the GOJ. The device consists of a three-axis translation stage where a tissue sample embedded in wax can be sequentially imaged and milled. At each step the top surface was stained for fiber type and connective tissue and the image captured using a high resolution digital camera. Proof of principle was demonstrated with an en-bloc harvested sheep GOJ and then repeated with a fresh autopsy human GOJ. The 3D microstructural model was constructed using the images with a total volume of 35.1 × 106 voxels. Clinical manometric measurements were used to inform mathematical modeling to simulate physiological events, such as swallowing. Conclusions  This model may provide opportunities to examine the relationship of anatomy and physiology in health and disease of the GOJ, enhance patient education, enable theoretical drug trials and determine the relative importance of anatomical elements of anti-reflux surgery.