Abstract Body (Do not enter title and authors here): Introduction
Fontan associated liver disease (FALD) is an important complication of the Fontan Circulation. The presence of esophageal varices is associated with increased morbidity and mortality in patients with underlying cirrhosis. The diagnostic yield of routine esophagogastroduodenoscopy screening (EGD) in Fontan patients with clinical/radiographic suggestion of cirrhosis is unknown with wide practice variation across centers. At our center, the institutional strategy is to refer patients with clinical or radiographic evidence of FALD to the hepatology service. All patients seen by hepatology undergo EGD if they have clinical/radiographic suggestion of cirrhosis and they are clinically stable and without contraindications to the procedure. The purpose of this study was to evaluate the yield of EDG in Fontan patients and inform a strategic surveillance approach.

Methods
We performed a single-center retrospective chart review of all patients with Fontan circulation who underwent an EGD from February 1, 2020 to October, 31 2023 at our center.

Results
During the study period, a total of 66 patients (51.5% male) with Fontan circulation underwent routine EGD at a median age 30.2 years (range 19.8-60.4 years). The median time from Fontan palliation to initial screening EGD was 27.1 years. Fontan type was lateral tunnel in 41 patients (62.1%), atriopulmonary in 14 (21.2%), and extracardiac in 11 (16.7%). About half (48.5%) of the patients had a systemic left ventricle. At the time of the EGD, 12 (18.2%) patients had a New York Heart Association (NYHA) functional class I, 35 (53.0%) had a functional class II, 19 (28.8%) had a functional class III. The esophageal varices were present in 41 (62.1%) patients, of which 35 (53.0%) had grade I esophageal varices, and 6 (9.1%) had grade II. Additional findings included portal hypertensive gastropathy in 33 (50.0%) patients, erythematous mucosal changes in 16 (24.2%), non-bleeding erosive gastropathy in 4 (6.1%) and gastric vascular ectasia in 1 (1.5%).

Conclusion
This study showed a high prevalence of esophageal varices in our Fontan patients, suggesting a role for routine EGD as a screening tool in this population.