Advantages and limitations in minimally invasive cardiac surgery

The introduction of endoscopic technology to cardiovascular surgery was significantly delayed compared to abdominal and lung surgery, although it has been gradually introduced in this field during the past decade in closure of patent ductus arteriosus, repair of the vascular ring, implantation of pacemaker leads or AICD, and pericardectomy. Endoscopic technology also started to be used in harvesting saphenous vein grafts (SVG) and the left internal thoracic artery for coronary artery bypass grafting(CABG) from the mid-1990s. Although complete endoscopic surgery has not yet been established in the major field of standard cardiovascular surgery, many cardiac surgeons attempt to minimize the size of chest wounds with 6- to 8-cm skin incisions, which is called minimally invasive cardiac surgery (MICS) or minimally invasive direct coronary artery bypass (MIDCAB). Complete endoscopic cardiac surgeries were performed utilizing the Zeus system and Da Vinci system at the end of the 20th century. Another method to minimize the invasiveness of CABG is to perform it without cardiopulmonary bypass, so-called off-pump coronary artery bypass (OPCAB). Currently, less-invasive procedures are mainly applied for relatively simple cardiac surgeries, although these procedures are also potentially effective to avoid postoperative cerebral or respiratory complications in high-risk patients. MICS is effective in reducing the size of surgical wounds and in decreasing intraoperative blood loss. On the other hand, the duration of anesthesia and surgery can be prolonged due to technical difficulty, and the risk of unsatisfactory anastomosis or incomplete revascularization can also be increased. The cardiopulmonary bypass circuit utilized for MICS requires a more complicated system including negative pressure venous drainage. The detection of accidental trouble during surgery, which is related to the extracorporeal circulation or the MICS procedure itself, can be delayed due to the limited surgical view. MICS procedures carry additional risks related to the more complicated cardiopulmonary bypass system and small surgical wound. We must be deliberate in determining the indications for MICS and obtain complete informed consent from patients when we perform MICS, including informing them of the additional risks related to the MICS procedure itself and the possibility of conversion to standard open-heart surgery.