by W. Randolph Chitwood, Jr. and Vassilios Gulielmos

 « Guest Commentary

What is minimally invasive cardiac surgery?

Since the early 1980s our cardiology colleagues have continued to convince the public that heart and blood vessel repairs can and should be done through small groin punctures and after several hours patients can return home. In this context our very successful contemporary operations for coronary, valvular, and pulmonary surgery have paled in the eyes of the public. They see neighbors going to the hospital to return home several hours later and go to work the next day. This “less invasive” expectation is what the public has grown to want and demand. When it comes to cardiac surgery, patients want “minimal” no matter what and really haven't any idea that new methods can introduce parallel compromises in surgeon comfort, safety, and quality. At the same time patients and cardiologists demand the best surgical operation with excellent long-term results, features that the “puncture approach” still aspires to attain.

Thus, in the early 1990s surgeons began to develop alternative, less traumatic methods for performing cardiothoracic surgery. Although off-pump coronary surgery via a sternotomy was being done by a few surgeons, the era of minimally invasive cardiac surgery really was born when the Stanford cardiac surgeons imagined performing cardiac surgery through a few stab incisions or “ports”. Surgeons began to type-cast all approaches as “minimally invasive” no matter what - either not using the pump but continuing with a full sternotomy - or using a small incision still requiring cardiopulmonary bypass. To this end, surgeons became somewhat schizophrenic, often fooling ourselves into asking - What is minimally invasive cardiac surgery?

The definition “every procedure that reduces perioperative trauma is minimally invasive” is not enough. Smaller skin incision could be minimally invasive, but how small? Avoiding cardiopulmonary perfusion is as well, but can we combine off-pump surgery with tiny incisions? Avoiding sternal splitting completely or sawing just one part - the top or bottom - seem less traumatic, but are pump times longer with operative access impaired? Endoscopic and robotic cardiac operations seem ideal to perform “port-like” operations but have a steep learning curve, requiring long perfusion times as well. For many they are minimally invasive to the patient and maximally stressful for the surgeon. What is minimally invasive about these scenarios? More pump time & less incision or no pump time & bigger incision? Perhaps modified cardiopulmonary perfusion circuits comprised of bio-inert materials will be the minimally invasive “holy grail” making operative time irrelevant? Avoiding aortic clamping, either during cardioplegic arrest or proximal anastomoses, may be neuroprotective - certainly this is minimally invasive to the brain. When conventional suturing is replaced by anastomotic devices, safer, less traumatic surgical options evolve. Can we really include saphenous harvesting in this discussion, as many surgeons have used multiple small incisions for years providing ideal vein grafts? Endoscopic radial artery harvesting has progressed to a “watchband incision”. Last year a long arm incision for this procedure was considered minimally invasive as it was combined with off-pump grafting.

We propose that minimally invasive cardiac surgery really is a philosophy and not a specific method or technique. A constellation of new routines, methods, and techniques all are directed collectively toward speedily returning patients to normalcy. Surgical (small incisions, off-pump methods, proximal connectors), perfusion (minimal prime, bio-compatible circuits, hemo-concentration), and anesthetic techniques (fast-acting agents, less invasive monitoring) can be combined with early extubation and ICU fast-tracking, followed by early discharge and daily telephone follow-up at home. Who will argue with this seemingly ideal matrix?

During development of this new CTSNet innovation center, we posed these same questions to each other and came up with completely different answers. No doubt you also will have the same difficulty, but we call on you, as well as our industry partners, to help us solve this conundrum. To date, we really have no good nomenclature to define these new methods that rapidly are becoming standard. Is there really “minimally invasive cardiac surgery” or has it become just plain “cardiac surgery”? Are minimally invasive operations truly innovative, really less traumatic, or just new? Our critics are justified in challenging us as we haven't answered these questions very well ourselves. Critics may laugh and zealots may defend, but, the sentinal question still begs us - What is minimally invasive cardiac surgery?