First-in-Human Percutaneous Cor Triatriatum Sinistrum Balloon Membranoplasty to Facilitate Percutaneous Mitral Transcatheter Edge-to-Edge Repair

Cor triatriatum sinistrum (CTS) is a rare congenital structural heart defect conventionally managed surgically early in life. However, at times it is discovered much later. We present the first in-human case of a transcatheter CTS membranoplasty with mitral transcatheter edge-to-edge repair (mTEER) in an elderly patient with CTS. Ultimately, the patient experienced reduction in mitral regurgitation (MR), translating to significant symptomatic improvement. Although surgical resection is the standard treatment for CTS, this approach may not be suitable for high-risk elderly individuals with multiple comorbidities. To address this, we employed a novel percutaneous technique, using multiple guidewires and balloons to facilitate controlled traversal and dilation of the atrial membrane, creating adequate space for mTEER. Percutaneous membranoplasty combined with mTEER may offer a feasible and potentially preferable alternative to surgery for elderly patients with CTS who are considered high-risk surgical candidates.