62: Preserving Ventriculoarterial Balance: ECLS for Acute Lung Pathology in Truncus Arteriosus with Severe Pulmonary Hypertension - A case Report

Background: Adult survival with unoperated Truncus Arteriosus (TA) is exceedingly rare and is typically complicated by advanced pulmonary vascular disease and Eisenmenger physiology. In this population, invasive positive-pressure ventilation (IPPV) can exacerbate right-to-left shunting and increase pulmonary vascular resistance (PVR), precipitating profound hemodynamic instability. Extracorporeal life support (ECLS) offers an alternative strategy by providing extracorporeal gas exchange while avoiding the adverse cardiopulmonary effects of elevated airway pressures. Case Presentation: We report the case of a 33-year-old man with persistent truncus arteriosus and severe pulmonary hypertension who presented with acute hypoxemic and hypercapnic respiratory failure due to a lower respiratory tract infection. Despite escalation to high-flow nasal cannula therapy, respiratory failure progressed with worsening hypercapnic acidosis. Given the substantial risk of hemodynamic collapse associated with IPPV in the setting of Eisenmenger physiology, extracorporeal carbon dioxide removal (ECCO2R) was initiated as a rescue therapy. Intervention and Outcome: ECCO2R enabled effective correction of hypercapnia and respiratory acidosis while entirely avoiding positive-pressure ventilation. Concomitant initiation of targeted pulmonary vasodilator therapy further optimized right ventricular loading conditions. The patient demonstrated progressive clinical and gas exchange improvement, allowing successful decannulation from ECCO2R after five days. He was subsequently discharged from the intensive care unit on low-flow supplemental oxygen by hospital day nine. Conclusion: This case underscores the potential role of ECLS, specifically ECCO2R, as a safe and effective alternative to IPPV in selected adults with congenital heart disease and advanced pulmonary hypertension. In high-risk physiologic states where positive-pressure ventilation may worsen shunt physiology and pulmonary vascular load, ECCO2R can serve as a valuable bridge to recovery during reversible respiratory decompensation.