Neonatal Pulmonary Arteriovenous Malformation: A Neonate With Pulmonary Hypertension

Abstract

INTRODUCTION: Symptomatic pulmonary arteriovenous malformation (PAVM) in the neonate is a rare occurrence. We present a neonate with PAVM who was supported with extracorporeal membrane oxygenation (ECMO) while successfully treated via cardiac catheterization. CASE PRESENTATION: Baby I was transported to our pediatric intensive care unit on day of life (DOL) 3 for possible ECMO support. At the time of transport she was being treated with high frequency oscillatory ventilation, nitric oxide (NO), vasopressors, antibiotics and acyclovir. The A-a gradient was 608, and the oxygenation index was 47. A chest radiograph revealed left lower lobe atelectasis (figure 1). An echocardiogram revealed normal anatomy, patent foramen ovale with bi-directional flow, right ventricular pressure at least equal to one-half systemic pressure and good bi-ventricular function. Baby I was supported with ECMO for 16 days during which time she was treated with NO, sildenafil and prostacyclin. Multiple attempts at weaning off ECMO were unsuccessful secondary to hypoxemia. Baby I was taken to the cardiac catheterization laboratory on DOL 19. An angiogram revealed 2 PAVMs in the left lower lobe (figure 2). The PAVM feeding vessels were occluded with vascular plugs. Baby I returned to the PICU off ECMO support. She was discharged from the hospital soon there after. DISCUSSION: The association of pulmonary hypertension with PAVM is unusual. In a post-mortem report of a neonate with a large pulmonary artery fistula (PAF) and valvar pulmonary stenosis, Russell et al. (1) speculated that the stealing of blood flow by the PAF from the normal developing pulmonary capillary beds inhibited their normal development and arborization thus contributing to the suprasystemic right ventricular pressure that occurred after ligation of the PAF. Vincent et al. (2) demonstrated an acute rise in pulmonary arterial pressure (PAP) within 10 minutes of balloon occlusion of a PAVM, suggesting that measurement of both PAP and pulmonary vascular resistance (PVR) in the presence of a large, low resistance PAVM may severely underestimate the true PVR of the remaining, potentially normal lung. CONCLUSIONS: This report reminds us that when difficulty weaning off ECMO occurs repetitively we should consider less common conditions. The primary condition may be one that is treatable and has a good prognosis.