Predictors of protein losing enteropathy after Fontan completion: An 8-year retrospective study at Sheikh Khalifa Medical City

Abstract

Background: The Fontan procedure is the final stage of a three-stage palliation process in patients born with a univentricular heart as part of hypoplastic left heart syndrome (HLHS) or other pathologies with a univentricular heart. As essential as this procedure has proven to be for such cases, the Fontan physiology diminishes cardiac output and expands systemic venous pressure, which then leads to venous congestion that can be complicated by protein-losing enteropathy (PLE). This retrospective study aimed to identify the predictors of such complications in all patients who underwent completion of the Fontan procedure at our center (Sheikh Khalifa Medical City/SKMC) in the past eight years. Methods: This study examined the medical records of patients who underwent completion of Fontan repair at our center since the inauguration of the cardiac surgery program of SKMC in the United Arab Emirates (UAE). Exclusion criteria included the absence of any of the required predictors in a medical report. Patients were divided into two groups: those who developed PLE and those who did not. For each group, the following data were collected: degree of AV valve regurgitation, ventricular function, invasive SVC, pulmonary pressure before Fontan completion, and original cardiac diagnosis. Results: Of the 48 included patients,13 (25%) developed PLE. Multivariate regression analysis showed that the best predictors of PLE were AV valve regurgitation (P=0.02), SVC mean pressure (P =0.006), and ventricular function (P =0.02). Oxygen saturation <83% prior to Fontan completion was 92% sensitive in predicting PLE after Fontan completion. Conclusion: This is a single-center study of the predictors of PLE after Fontan procedure and, as expected from similar studies, moderate AV valve regurgutation and a dominant right ventricle were good predictors of Fontan failure. The higher prevalence of PLE in our cohort as well as lower cut-offs of SVC pressure that can predict complications might be related to the predominance of hypoplastic left heart in the operated patients, which has been the main referral center for cardiac surgeries in UAE in the last decade.