Gastrointestinal Nutrient Transit and Enteroendocrine Function After Upper Gastrointestinal Surgery

The incidence of oesophagogastric cancer has increased by 400% since the 1970s in Ireland and the United Kingdom. In addition, refinement of perioperative management and the now widespread use of multimodal protocols for patients with locally advanced disease have significantly improved outcomes for patients with oesophagogastric cancer treatable with curative intent. Despite significant advances in chemoradiotherapy, surgical resection remains the primary curative option. Unintentional weight loss and nutritional complications represent serious concerns for patients after radical resection, even among those who remain free from recurrent disease in the long-term. A study from the Swedish Esophageal and Cardia Cancer Registry reported a mean three year weight loss of 10.8% among disease-free patients, with 33.8% of this cohort demonstrating malnutrition at three years post-oesophagectomy. Mechanisms contributing to weight loss for disease-free patients after upper gastrointestinal surgery are poorly understood, however an association between increasing magnitude of weight loss and the presence of increased satiety is described. Our recent studies at SJH have demonstrated four fold elevated postprandial satiety gut hormone concentrations after oesophagectomy, compared with baseline preoperative values. Postprandial gut hormone levels correlate significantly with postprandial symptoms and altered appetite at 3 months postoperatively, and with body weight loss at 2 years postoperatively. However, the mechanism leading to exaggerated postprandial gut hormone production after upper gastrointestinal surgery is poorly understood, limiting targeted therapeutic options. In this study, we aim to characterise the role of altered nutrient transit and enteroendocrine cell function in the pathophysiology of excessive post-prandial gut hormone responses after upper gastrointestinal surgery. To do this, we will measure the gut hormone response to a standardised 400 kcal meal, as