MINI OPCAB Operation: Surgical Technique

We describe how to perform left internal mammary artery (LIMA) bypass to the left anterior descending (LAD) artery, the so-called MINI Off-pump Coronary Artery Bypass (MINI OPCAB).

We included patients with a demonstrated predominant ischemia related to the LAD territory. Of 70 patients who were operated upon at the Benetti Foundation, 10 received hybrid revascularization.

The patient is prepared as for a standard coronary bypass operation through sternotomy. The sternum is opened to the 3rd or 4th intercostal space depending on the anatomy, and a retractor is put in place. The left mammary artery is generally dissected to about 8 cm and isolated without the veins. Importantly, the angle of the superior part, where the mammary artery is attached to the sternum, needs to be below 20% to avoid any potential kinking. The pericardium is cleaned to identify the area of the pulmonary artery. The pericardium is opened to the apex and towards the right to around 5 to 6 cm initially. In most cases, the area of the LAD can be seen and the potential area of the anastomosis is defined. The patient is heparinized and the LAD is occluded with 5-0 Proline. A mechanical stabilizer is put in place and the anastomosis is performed. When the bypass is finished, and before sutures are tied, the stitches of 5-0 polypropylene around the artery are released, along with the clamp of the mammary artery; the anastomosis is then tied. The mechanical stabilizer is removed, the stitches of the pericardium are released and the flow of the graft is measured, while ensuring that there is no kinking. If the flow and Pulsatility and Resistance (PR) are acceptable, the mammary is fixed with 2 stitches of 7-0 polypropylene on both sides around 1 cm from the anastomosis. The heparin is reverted with protamine and a drain is put in place, while taking care to avoid any chance of touching the mammary artery or the anastomosis. The sternum is closed with 1 or 2 wires.

Operative mortality in this series was 0%; one patient was converted to sternotomy off-pump (1.4%). None of the grafts were revised after measurement with a Medistim system (Medistim ASA, Oslo, Norway). Fifty five patients (79%) were extubated in the operating room The average hospitalization stay was 60 hours (SD 17, 95% CI). Sixteen patients who underwent the LIMA-to-LAD procedure were restudied, with 100% patency. At 144 months, 82% of the patients were alive and 68% were asymptomatic.

Additional clinical experience is required to be able to reproduce this operation on a large scale and expand the MINI OPCAB operation in hybrid revascularization.