The Egg Muffin Technique—A Novel Bipatch Enfolding Repair for Membranous Ventricular Septal Aneurysm with Aortic Valve Replacement: A Case Report

A 70-year-old man with severe aortic stenosis was referred to our department for surgery. Echocardiography revealed a peak/mean pressure gradient of 101/61 mm Hg and a membranous ventricular septal aneurysm protruding into the right ventricular outflow tract without shunt flow. Right heart catheterization demonstrated right ventricular outflow tract obstruction with a peak pressure gradient of 11 mm Hg. Aortic valve replacement using a bioprosthetic valve and enfolding repair of the membranous ventricular septal aneurysm were performed. The folded aneurysmal tissue was compressed and reinforced with double-applied patches from both the left and right ventricular sides via aortotomy and right atriotomy, respectively. The postoperative course was uneventful. This novel Bi-Patch Enfolding Repair, termed the "egg muffin technique," provides a simple and effective method for volume reduction of aneurysmal tissue. Unlike aneurysm resection with defect closure, it mitigates the risk of iatrogenic shunt formation and atrioventricular block.