経皮的左心房付属器閉鎖術：現在のエビデンスと手技的洞察

Atrial fibrillation (AF) is the most common sustained arrhythmia and a major cause of cardioembolic stroke, with the left atrial appendage representing the predominant site of thrombus formation. Oral anticoagulation (OAC)-particularly with direct oral anticoagulants-remains the cornerstone of stroke prevention; however, contraindications and bleeding risks limit the use of OAC in selected patients. Percutaneous left atrial appendage closure (LAAC) has emerged as a device-based alternative to oral anticoagulation. Moreover, the indications of LAAC are expanding to include recurrent ischemic stroke despite adequate anticoagulation and patients with advanced chronic kidney disease. Thus, this review synthesizes the current evidence on LAAC and provides a practical, step-by-step procedural roadmap, from preprocedural imaging with transesophageal echocardiography or cardiac computed tomography and anatomical sizing, to transseptal puncture, device selection, deployment, and release criteria, as well as intraprocedural imaging and hemodynamic assessment. Advances in imaging modalities, procedural planning, and device technology have improved both efficacy and safety. However, postprocedural antithrombotic strategies remain heterogeneous and the subject of ongoing clinical trials. Future research is expected to refine patient selection, optimize pharmacotherapy after LAAC, and further define the role of LAAC in the contemporary management of AF.