Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) is a minimally invasive approach that in selected patients is a fantastic alternative to conventional Coronary Artery Bypass Grafting (CABG) surgery.
The latter requires a 10-12 inch incision to cut through the sternum (sternotomy), whereas MIDCAB surgery can be performed through a 3 inch incision placed between the ribs on the left hand side of the chest. MIDCAB is beating-heart surgery, which means that stopping the heart (cardioplegia) is not necessary and a heart-lung machine (cardiopulmonary bypass, CPB) is not required – this is commonly known as off-pump CABG or OPCAB for short. Nevertheless, MIDCAB has the same benefits as conventional bypass surgery of restoring adequate blood flow and normal delivery of oxygen and nutrients to the heart.
The greatest benefit of MIDCAB surgery over a sternotomy approach is speed of recovery with usually only a 3-4 day post-operative hospital stay (as opposed to 5-7 days) and return to normal activities in about 3 weeks (rather than 3 months), although some recover faster than this and some recover slower. There is also less pain, less blood loss and fewer wound infections after MIDCAB surgery than with conventional CABG. I generally reserve the use of this procedure for a single bypass graft (left internal mammary artery) onto the coronary artery on the front of the heart. For bypassing two or more arteries, conventional CABG is indicated.
An exciting development at Liverpool Heart and Chest Hospital that is coming in Q3 2013 is that we will be moving to a robotic platform (da Vinci revascularization) to perform the procedure. This has become the standard of care at certain specialist centres in the US and Europe and is the least invasive surgical approach possible to treat coronary artery disease. The great advantage that the da Vinci Si system confers for the patient is that the left internal mammary artery can be harvested without any rib-spreading at all, a manoeuvre that markedly reduces post-operative discomfort. For the surgeon, 3D high-definition imaging, motion-scaling and 7 degrees of freedom (meaning all the natural movements of the human hand and arm are replicated) all facilitate the procedure. This will firmly establish our position at the cutting edge of surgical innovation in Europe.
How do surgeons perform surgery on a beating heart?
A technical challenge in MIDCAB and sternotomy-based off-pump surgery is the difficulty of suturing or “sewing” two small vessels together, each about 1.5-2.0 mm diameter, on a moving target. This is facilitated by use of a stabilization system that is used to immobilise only the portion of the heart where the surgeon is operating. This stabilization system avoids use of the heart-lung machine by making it possible for the surgeon to accurately work on the patient’s heart while it continues to beat.