P2A090: PHACE Syndrome: Role of Cardiac Magnetic Resonance Imaging

Introduction: PHACE syndrome encompasses a constellation of features comprising Posterior fossa anomalies, Hemangiomas, Arterial lesions, Cardiac anomalies, Eye anomalies. The most consistent feature of PHACE syndrome is segmental hemangioma. Cardiovascular anomalies are seen in up to 40% of patients. We aim to describe the role of cardiac magnetic resonance imaging (CMR) in the management of patients with PHACE syndrome.

Case Description: Eleven patients with PHACE syndrome followed at our center had CMR studies from November 2011 to March 2023, representing one of the largest single-center cohorts of PHACE patients with CMR imaging in the literature. 1 patient underwent cardiac computed tomography (CT) as the initial imaging modality. The age at presentation ranged from 4 days to 17.5 years with a median age of 2.4 months. The median follow-up duration for the cohort is 5.4 years, ranging from 0 to 12.4 years. Coarctation of the transverse aortic arch was found in 2 of 11 patients, with 2 additional patients having a mildly hypoplastic transverse arch without hemodynamic consequences. Ascending aortic aneurysm was seen in 2 patients, one of which was associated with a bicuspid aortic valve. Another 2 patients had mild dilatation of the sinus of Valsalva and the Sino-tubular junction. Vascular ring was diagnosed in 2 patients, one with a right-sided arch with aberrant left subclavian and the second with a double arch. Persistent left superior vena cava (SVC) to the coronary sinus was seen in 2 patients, and partial anomalous pulmonary venous connection of the right upper pulmonary vein to the right SVC was found in 1 patient. Finally, one patient had an atrial and a ventricular septal defect. Brachiocephalic arterial vascular anomalies ranging from atresia, stenosis, hypoplasia, dilation, and aberrant origin of the innominate, common carotid, subclavian, or vertebral arteries were seen in 8 of the 11 patients..
Serial imaging performed to follow the progression of COA, arch hypoplasia and aortic aneurysm remained stable in the majority of the cohort. One patient demonstrated worsening coarctation and underwent surgical arch augmentation at 11 years of age, 9 years after her initial CMR evaluation. Another patient underwent division of the double aortic arch at 3.3 years of age.

Discussion: PHACE syndrome is associated with complex systemic arterial anomalies. Presence of infantile hemangioma >5cm warrants detailed cardiac evaluation starting with an echocardiogram. If the echocardiogram demonstrates concerns, CMR can readily delineate the complete thoracic vasculature. Limited information is available about the natural history of arterial and cardiac anomalies in PHACE syndrome. Therefore, select patients such as those with COA, arch hypoplasia, or aortic aneurysm benefit from serial CMR imaging to monitor progression and determine the appropriate timing for intervention.

Conclusion: CMR is an integral component of the management of patients with PHACE syndrome.