What are closed heart operations?

Ligation of Patent Ductus Arteriosus (midaxillary incision) Off-pump coronary artery bypass Pace maker implantation (Skin incision, Sub-clavian vein puncture, Lead(s) introduction using Seldinger technique., Operative theater using a C-arm with Xray.) Pericardiocentesis Surgical drainage Pericardial window