Giant Morgagni hernia and aorto-pulmonary collaterals in a Loeys-Dietz patient undergoing surgery for aortic root aneurysm and mitral valve prolapse.

The case of a Loeys-Dietz syndrome patient undergoing mitral valve repair and composite aortic root and valve replacement is here described: preoperative CT scan unravelled a previously misdiagnosed Morgagni hernia (anterior diaphragmatic), containing omentum only, compressing the right ventricle. Intraoperatively, an abnormal oxygenated blood backflow into the left ventricle was observed, postoperatively found to be caused by major aorto-pulmonary collateral arteries. This is the 1st case of Morgagni hernia and systemic-pulmonary shunt ever reported associated with Loeys-Dietz syndrome. These congenital features may be important in both phenotyping and surgical management.