Traditionally, over the past few decades, cardiac surgeries were performed through sternotomy (a large cut on the chest and splitting of the breast bone) to gain access to the heart. Not only does the large incision result in a long, unsightly scar, but more importantly, it translates into more pain, more physiological trauma, a longer hospital stay and a longer recuperation period.
As understanding of cardiac surgery and technology improve over time, techniques for cardiac surgery have been improvised to reduce the pain and suffering for the patients while maintaining the safety and efficacy of the surgery.
Minimally invasive cardiac surgery (MICS) is well developed and recognised now in most parts of the world. In fact, in most tertiary centres, for example in Cleveland Clinic in the United States of America, most cardiac surgeries were performed via MICS. Following strict criteria, the length of incision for MICS is defined as less than 4 inches.
To date, MICS has been most widely applied for coronary artery bypass surgery (CABG) and cardiac valvular surgery.
For minimally invasive direct coronary artery bypass surgery (MIDCAB), the left internal mammary artery (LIMA), which is unequivocally the best conduit and offers the best long-term patency, can be harvested via 3 different ways:
- A small anterior thoracotomy of 6-8cm in length
- Video-assisted thoracoscopic (VATS)
Each of these approaches has its own pros and cons. There is a certain learning curve and hence it is important for the surgeon to be well versed in such approaches.
Following the harvest of LIMA, the artery will then be anastomosed to the most critical left anterior descending artery to offer patients the best long term outcome. During the operation, as a result of off pump technique and minimal manipulation of the heart, the patient is more stable hemodynamically and the amount of bleeding is also much less.
MICS is also currently being widely utilised for isolated cardiac valvular surgery, especially mitral valve repair / replacement, tricuspid valve repair / replacement and aortic valve replacement. Most commonly, this is performed via partial sternotomy through a 6-8cm incision. For mitral and tricuspid valve surgery, it can also be approached via a small right anterior thoracotomy or via robotic–assisted surgery.
In the hands of a trained cardiac surgeon, these minimally invasive approaches will offer patients the least physical and psychological trauma while preserving the aim of the surgery in utmost safety. Typically, after MICS, the patient can be discharged from the hospital in 3-4 days time and resume most of their usual activities within 2-4 weeks.
This state-of-the-art development of MICS has continued to evolve and has also been successfully applied in other cardiac surgeries, including atrial septal defect closure, tricuspid valves repair, DOR procedure (chronic heart failure operation), and removal of left ventricular thrombus, arrhythmia surgery and ventricular septal rupture.
In the current era of medicine, it may be difficult to offer perfect treatment options for a patient with complex heart disease. In a patient with ischemic heart disease, some coronary artery may be more suitably dealt with by angioplasty and stenting, while some coronary artery, especially the left anterior descending artery, may be better off with a CABG and LIMA anastomosed to it. In a patient with cardiac valvular disease coupled with coronary artery disease, this patient will undergo a full sternotomy using conventional methods to fix both the valve and coronary artery stenosis.
However, with the development of MICS and increasing collegiality between cardiologists and cardiac surgeons, the hybrid approach to a patient with cardiac conditions can now offer a new perspective in treatment planning and work towards the best interest of patients.
In a patient with multiple coronary artery diseases, it is without argument that LIMA – LAD anastomosisoffers the best long-term patency and patient survival.Total artery coronary artery bypass is often raised by many surgeons and appears attractive interms of clinical outcomes. However, in real life, this happens only in less than 20% of the cases.
On the other hand, although PCI with stents is least invasive among all revascularisation interventions and the technology of coronary stents have evolved dramatically, its outcome still cannot match LIMA – LAD, which offers a 20 years patency rate of more than 90%.