171: PULMONARY THROMBOSIS IN PATIENTS WITH CONGENITAL HEART DISEASE

Abstract

Introduction: Pulmonary thrombosis (PT) is increasingly being diagnosed in the pediatric population. Congenital heart disease (CHD) patients, especially those undergoing single ventricle palliation (SVP), have a unique interplay between systemic and pulmonary circulations. Cardiac output in this population is dependent upon low-resistance pulmonary circulation to facilitate passive systemic blood flow to the lungs. Patients with CHD can have significant effects from PT including shock and death. We described characteristics of patients with CHD diagnosed with PT at our institution. Methods: We performed a retrospective chart review of the cases of PT associated with CHD at Texas Children’s Hospital from 2017-2022 Results: Out of 189 patients identified with PT, 13 patients had CHD. Four patients were excluded due to either insufficient data or because their primary diagnosis was ultimately endocarditis, not PT. Five patients (56%) had undergone SVP, with two following second stage of palliation (Cavo pulmonary anastomosis) and 3 during the third stage of palliation (Fontan). SVP patients developed PT while on anticoagulation (AC)per institutional practice standards. Two patients had PDA thrombus with subsequent extension to the pulmonary artery (PA), another had PDA dependent right PA flow and developed clot in right PA. One patient developed thrombus in the PA outpouching at site of Tetralogy of Fallot repair. The population primarily consisted of infants under the age of 1 year (67%). The primary presenting symptom was hypoxia (67%) with two presenting with hypoxemic bradycardic arrest (22%). All patients were initiated on systemic AC. Seven patients (78%) underwent interventional management including attempted mechanical thrombectomy with or without site-directed thrombolysis, two of whom (22%) also required ECMO cannulation for hemodynamic compromise. Two patients were managed with AC alone. All patients survived to discharge. Conclusions: This review demonstrates the importance of identifying PT in the pediatric CHD population and the need for aggressive interventional management and anticoagulation. The survival of all patients in this cohort is likely secondary to a multidisciplinary systemic approach. A high index of suspicion should be maintained, especially in the single ventricle population.