Postoperative mitral leaflet rupture in an infant with Loeys–Dietz syndrome

This report describes an infantile case of Loeys–Dietz syndrome (LDS) with spontaneous mitral leaflet rupture. The patient was diagnosed with a type B interruption of the aortic arch. Bilateral pulmonary artery banding was performed 5 days after birth. On the 53rd day, intra‐cardiac repair was performed without valvuloplasty. Although the operation was successful, mitral regurgitation deteriorated at 4 weeks after operation. On the 88th day, a mitral valvuloplasty was performed and a severely ruptured anterior leaflet was observed. Seven days after valvuloplasty, the mitral valve insufficiency again worsened and a fourth operation was performed. Two tears were observed in the anterior and posterior mitral valve leaflets, and a mitral valve replacement was required. Subsequently, the patient was diagnosed with LDS according to gene mutational status. LDS is known to have a poor prognosis with cardiovascular complications, but valve rupture has not been previously reported in other cases.