Minimally invasive mitral valve surgery (MIS) refers to a collection of techniques and operation-specific technologies, all of which are designed to lessen surgical trauma and improve clinical outcomes. In the last 20 years, enhanced visualization and instrumentation as well as modified perfusion and aortic occlusion methods have propelled the development of MIS operations. Cohn and Cosgrove (1996) first modified cardiopulmonary bypass techniques to enable safe, effective, minimally invasive aortic and mitral valve surgery.1–3 Concurrently, innovative port-access methods, using endo-aortic balloon occlusion, were proven to be effective.4,5 Thereafter, video-assisted and robotic methods were developed and applied effectively by several surgical groups.
Despite acceptance today, many surgeons initially were very critical of performing any complex valve operations through small incisions, owing to safety risks and the possibility of inferior results.6,7 Since then many institutions worldwide have published excellent MIS comparative outcomes with traditional surgery. These showed definite clinical advantages, which included decreased blood loss and less transfusions as well as minimal postoperative care and pain. Collectively, these translated into shorter hospital stays, faster return to normal activities, less use of rehabilitation resources, and overall healthcare cost savings. Each of these advantages has been a driver for the continued development and expansion of MIS operations.
Today, replacing and repairing cardiac valves through small incisions is a standard practice. The combination of alternative sternal and thoracotomy approaches, new aortic clamping techniques, modified cardiopulmonary bypass circuits and cannulas, shafted-instruments, and three previous generations of robotic systems, all have set the stage for current minimally invasive and robotic mitral surgery, which has gained acceptance at many centers worldwide. Large institutional series as well as several meta-analyses have confirmed that MIS mitral valve surgery is safe and effective for most patients.8–14 Although overall mitral repair rates in the United States have increased from 51% in 2000 to 62% in 2010, adoption of minimally invasive operations lags behind at less than 30% of repair cases.15–17 In comparison, in 2015 nearly 50% of over 5000 mitral valve repairs in Germany were done minimally invasively.18 At our center, mitral repair rates approach 100% for both MIS and robotic operations in selected patients with degenerative mitral disease.
With better understanding of the natural history of degenerative mitral valve disease, more asymptomatic patients now are being referred for repairs. Recent 2014 ACC/AHA (United States) and/or 2012 ESC/EACTS (European) Heart Valve Guidelines suggested that these patients should be referred only to high volume centers, having a heart team approach with a 95% chance of a repair and less than 1% operative mortality.19,20 These same “high bar” standards now have been set for minimally invasive repairs. To this end, surgeons who plan to embark on this trek should have significant experience in repairing valves through a sternotomy as well as have a significant patient volume, a unified heart team, and full support from ...