Superior septal approachを用いた右小開胸下僧帽弁手術―二弁同時介入を可能とする広大なワーキングスペースの構築

Mitral Valve Surgery via Right Mini-thoracotomy Using the Superior Septal Approach：Construction of a Wide Working Space for Concomitant Double-valve Procedures

近年，低侵襲心臓手術の普及に伴い，右小開胸下僧帽弁手術は広く行われるようになった．一方で複雑な逆流機序をもつ僧帽弁形成困難例や，僧帽弁のみならず大動脈弁や三尖弁，左心耳などへの同時介入を要する症例も増加している．これらを右小開胸下に安全かつ高精度に施行するためには，広大なワーキングスペースの確保と，視野軸を意識した術野の構築が不可欠である．

Right mini-thoracotomy mitral valve surgery has been widely adopted in Japan as a minimally invasive approach. However, concomitant aortic valve intervention in addition to mitral and tricuspid valve procedures remains uncommon through this approach. To overcome this limitation, we have developed a surgical strategy using the superior septal approach （SSA）, which provides a wide working space and facilitates multiple-valve procedures through a single right mini-thoracotomy. This approach provides a close and near-frontal view of the mitral valve by positioning the operative field immediately beneath the thoracotomy wound. This exposure allows complex mitral valve repairs, including posterior leaflet augmentation and repair for Barlow’s disease, to be performed in a manner similar to conventional surgery via median sternotomy. In addition, although the mitral and aortic valves differ in anatomical orientation, SSA enables both valves to be aligned along a similar visual axis. Although SSA may cause transient junctional rhythm due to its proximity to the sinoatrial nodal artery, it may represent a useful option for standardized multiple-valve procedures through a right mini-thoracotomy.