Background: Over the past two decades, minimally invasive techniques for classic heart valve surgery and isolated bypass surgery have been developed that enable access to the heart via partial sternotomy for most aortic valve procedures and via sternotomy-free mini-thoracotomy for other procedures.
Methods: We review the current evidence on minimally invasive cardiac surgery on the basis of pertinent randomized studies and database studies retrieved by a selective search in the MEDLINE and PubMed Central databases, as well as by the Google Scholar search engine.
Results: A PubMed search employing the search term "minimally invasive cardiac surgery" yielded nearly 10 000 hits, among which there were 7 prospective, randomized, controlled trials (RCTs) on aortic valve replacement, with a total of 477 patients, and 3 RCTs on mitral valve surgery, with a total of 340 patients. Only limited reports of specified centers are currently available for multiple valvular procedures and multiple coronary artery bypass procedures. The RCTs reveal that the minimally invasive techniques are associated with fewer wound infections and faster mobilization, without any difference in survival. Minimally invasive procedures are technically demanding and have certain anatomical prerequisites, such as appropriate coronary morphology for multiple bypass operations and the position of the aorta in the chest for sternotomy-free aortic valve procedures. The articles reviewed here were presumably affected by selection bias, in that patients in the published studies were preselected, and there may have been negative studies that were not published at all.
Conclusion: Specialized surgeons and centers can now carry out many cardiac valvular and bypass operations via minithoracotomy rather than sternotomy. According to current evidence, these minimally invasive techniques yield results that are at least as good as classic open-heart surgery.