Minimally invasive coronary surgery: fad or future?BMJ 1998; 316 doi: https://doi.org/10.1136/bmj.316.7125.88 (Published 10 January 1998) Cite this as: BMJ 1998;316:88
This promising technique needs testing in randomised trials
- Massimo A Mariani (), Cardiac surgeona,
- Piet W Boonstra, Cardiac surgeona,
- Jan G Grandjean, Cardiac surgeona
Minimally invasive coronary surgery is a radical modification of conventional coronary artery bypass surgery and is performed through a small thoracotomy, the surgeon anastomosing the left internal mammary artery to the left anterior descending artery without the use of either cardiopulmonary bypass or cardioplegic arrest.1 2 Since its description in 1994,1 few new techniques in cardiac surgery have aroused such interest or had such a rapid diffusion. Initial enthusiasm, however, has been followed by a wave of scepticism. As the indications for minimally invasive coronary surgery become clearer it is time for a calmer apraisal.
Initial enthusiasm for the technique arose because it avoided the need for cardiopulmonary bypass3 and provided an opportunity to reduce the use of health- care resources. Inevitably there were early failures, and some investigators began to highlight the risks of the technique.4 The main concerns were an excessive rate of failure of the anastomosis and possible damage to the mammary artery during its harvesting owing to the difficult access. The reasons for the early failures included a lack of technical guidelines, which led surgeons to improvise; the lack of specific instruments, which led to “bricolage” with self made instruments; and finally the lack of general knowledge about the effects of minimally invasive coronary surgery. This lack of knowledge relates mainly to the effect of partial anticoagulation, as used routinely in minimally invasive coronary surgery, on the small vascular anastomoses. In conventional coronary surgery the use of cardiopulmonary bypass induces disturbances at many levels in the coagulation-platelet system,3 which paradoxically result in a protective effect against thrombosis in small vascular anastomoses.
The indication for minimally invasive surgery is an isolated proximal stenosis of the left anterior descending artery.1 2 5 Over 1400 patients in 60 centres throughout the world have been operated on successfully,1 and the technique has advantages over both percutaneous transluminal coronary angioplasty and coronary artery bypass grafting, especially in severe cases. Compared with angioplasty minimally invasive surgery requires a lower rate of repeat revascularisation at follow up,5 owing mainly to the long term beneficial effect of the anastomosis of the left inferior mammary artery to the left anterior descending artery. The advantage over conventional coronary artery bypass grafting is a reduction in the systemic inflammatory response, thanks to the avoidance of cardiopulmonary bypass, which results in a lower morbidity and a shorter hospital stay.6 7 These advantages should ultimately lead to a better quality of life for the patients7 and reduced use of healthcare resources.
The proportion of patients who can benefit from minimally invasive coronary artery surgery is unknown. Cardiologists tend not to refer patients with an isolated stenosis of the left anterior descending artery for surgery, and many are unaware of the possibilities of this new technique. Future development of minimally invasive coronary artery surgery will depend on prospective randomised comparisons with percutaneous transluminal coronary angioplasty and conventional bypass surgery.
In the meantime, however, the technique is still evolving. A hybrid procedure is being developed that uses minimally invasive coronary surgery for revascularising the left anterior descending artery (via an anastomosis) and angioplasty to revascularise the remaining coronary arteries. The rationale is that angioplasty of the left anterior descending artery has a worse prognosis and a higher rate of restenosis than that of the circumflex artery and the right coronary artery,8 9 while the results of a left inferior mammary artery to left anterior descending artery anastomosis are incontrovertibly good with conventional surgery9 and much better than results with vein grafts or alternative arterial grafts. There have been few reports of the hybrid procedure, but early results are promising.10 Whether the hybrid procedure represents the ultimate refinement of minimally invasive coronary surgery remains unknown and again needs to be answered by prospective randomised studies. But it holds out the prospect of cardiologists and cardiac surgeons working side by side to achieve the best results in terms of revascularisation at the lowest price in terms of patient discomfort and use of healthcare resources.