2024 FSA Podium and Poster Abstracts

P052: STROKE PRESENTATION IN AN ADULT WITH FONTAN PHYSIOLOGY
Mariana Rubini Silva Ceschim, MD; Cosmin Guta, MD; University of Miami/Jackson Health System

Introduction: For over four decades, the Fontan operation has been the cornerstone palliative solution for patients born with functional or anatomic single ventricle (Figure 1). This procedure allows most patients to have a normal life through early adulthood, when successful. As we enter the fifth decade of caring for these patients, it is evident that adult survivors face significant challenges due to multiorgan dysfunction, increased risk of requiring heart transplantation, and early mortality. We report a case of a patient with Fontan physiology who presented with a stroke alert.

Case Report: A 23-year-old male with a history of hypoplastic left heart syndrome, status post fenestrated lateral Fontan and pacemaker implantation due to complete atrioventricular block, was admitted for worsening protein-losing enteropathy and exacerbation of congestive heart failure. His course was complicated by altered mental status and a new-onset stroke, requiring emergent mechanical thrombectomy and revascularization performed by neuro IR.

Upon arrival, the patient was already intubated and on multiple pressors (epinephrine, vasopressin, and isoproterenol). He was also receiving a propofol infusion for sedation and received a bolus of rocuronium. A central venous catheter was present, and a left radial arterial line was placed while neurosurgery prepared for the procedure. He underwent right transradial diagnostic angiogram and mechanical thrombectomy of the left middle cerebral artery. The patient's blood pressure remained stable with minimal changes in pressor requirements, and he maintained an oxygen saturation of about 92-95% with an FiO2 of 75%.

Discussion: Fontan physiology involves two key components: a single ventricle pumping blood to the systemic circulation and passive pulmonary blood flow. Chronic non-pulsatile pulmonary blood flow leads to loss of distal pulmonary vasculature, increased pulmonary vascular resistance, and chronically elevated central venous pressure. Adequate pulmonary blood flow and cardiac output depend on preload and the transpulmonary gradient.

In this case, we hyperventilated the patient with a target EtCO2 around 30 mmHg. This intervention lowered his pulmonary vascular resistance, allowing an improved passive blood flow to the pulmonary circulation which maintained adequate oxygenation.

Baseline oxygen saturation below 90% is a risk factor for perioperative complications. Fontan patients are particularly sensitive to any decrease in systemic venous return that may occur with mechanical ventilation. Whenever feasible, non-cardiac surgery in Fontan patients should be performed at centers with interdisciplinary expertise in treating this high-risk patient group.

Hemodynamic goals and possible interventions for patients with Fontan physiology are summarized in Figure 2.

Figure 1. Hypoplastic Left Heart Syndrome (Obtained from Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities; public domain)

Figure 2. Fontan Physiology