Minimally invasive cardiac surgery

In this workshop we have heard about many of the exciting new developments within cardiac surgery under the very broad umbrella of what has become known as minimally invasive cardiac surgery. This is a rapidly evolving field with many ongoing technical and technological developments. Although there have been many reports over the last few years of what may be possible, few data exist comparing these various techniques with conventional procedures. The following discussion, which will largely focus on myocardial revascularization, will try to address some of the principles behind minimally invasive cardiac surgery, and discuss some of the ongoing controversies. It is of interest, and of some importance, to recall the historical development of cardiac surgery and, in particular, myocardial revascularization. The first left internal mammary artery (LIMA) to left anterior descending (LAD) coronary artery anastomosis was effected through a left anterior thoracotomy on a beating heart.1 The use of median sternotomy, a period of cardiopulmonary bypass (CPB) and various techniques of myocardial preservation were central to the development of improved operating conditions. This resulted in the evolution of surgical techniques which were safe and effective and that resulted in good early, midand long-term results. These techniques were reproducible and were easily able to be taught and, thus, become widely disseminated. Surgeons of widely different technical abilities were able to reproduce good results. This is the background against which we must compare the various developments encompassed within minimally invasive cardiac surgery. It is unlikely that any current developments in minimally invasive myocardial revascularization will lead to an improvement in the long-term results of the procedure compared to current conventional techniques. The underlying principle behind the minimally invasive approach must, therefore, be to reproduce the current results associated with conventional surgery, but to reduce the morbidity associated with those conventional procedures. In order to address this issue we need to ask two basic questions: first, are we reproducing the results of conventional surgery? Secondly, are we significantly reducing the morbidity of the procedure?