473. PARACONDUIT HIATUS HERNIA AFTER OESOPHAGECTOMY: INCIDENCE, RISK FACTORS AND MANAGEMENT

Hiatus hernia after oesophagectomy is an uncommon but serious complication of oesophageal cancer surgery. With improving long-term oncologic outcomes, post oesophagectomy hiatus hernia is an increasingly recognised entity in oesophageal cancer survivorship. The aim of this study was to assess the incidence of and risk factors for paraconduit hiatus hernia (PHH), and to describe management approaches in a tertiary referral centre. All patients undergoing oesophagectomy for cancer from 2008 to 2022 were included. Early PHH was defined as occurring within 3 months of index surgery, with all other PHH defined as late PHH. Surveillance computed tomography scans were undertaken among all disease-free patients to 5-years postoperatively. Kaplan Meier and Cox proportional hazards regression models were used to determine independent risk factors for PHH. 897 patients were studied. Early PHH occurred in 1.2%, and late PHH in 5.7% of patients. There was no late recurrence after early PHH. PHH was an asymptomatic radiologic finding in 45.5% of early and 84.3% of late cases. Median time to PHH was 15.7 months postoperatively. Nausea, abdominal pain and vomiting were the most common symptoms associated with PHH. Surgical intervention was required in 25.8% of cases, more commonly following early PHH (63.6%) as compared with late PHH (17.6%, P < 0.01). Operative approach (P < 0.001), extended resection of crura or diaphragm (P < 0.001) and male sex (P = 0.037) were associated with increased risk of hiatus hernia. Paraconduit hiatus hernia is an uncommon complication after oncologic oesophagectomy. Surgical intervention is often required for patients with PHH presenting in the first three months after surgery, but a majority of patients with asymptomatic late PHH may be managed expectantly.