Minimally invasive subclavian/axillary artery to coronary artery bypass (SAXCAB): review and classification

Subclavian/axillary artery to coronary artery bypass (SAXCAB) surgery is defined as a minimally (or less) invasive coronary revascularization procedure where one or more grafts are anastomosed to the second or third parts of the subclavian artery or any of the three parts of the axillary artery (inflow source) and attached to one or more coronary arteries, and where there are two separate minimally invasive incisions to expose the target coronary artery and the inflow sources, respectively. The indications and contraindications for SAXCAB surgery are discussed, and the relevant chest wall anatomy and that of the subclavian and axillary arteries are reviewed. The effect of respiration and anatomic variability as they impact the SAXCAB graft are discussed. Three components of the anatomy that are important in SAXCAB surgery are discussed: The relation of the first rib to the clavicle insofar as it affects access to the third part of the subclavian artery, the anatomy of the subclavian and axillary arteries and their branches, and the anatomy of the chest wall and its movement. In addition, the different SAXCAB variations that have been applied clinically are reviewed and classified, and future aspects of SAXCAB research are discussed. SAXCAB surgery is unique among the different types of minimally invasive direct coronary artery bypass (MIDCAB) surgery because of the enormous diversity of the techniques that have been described. Based on these descriptions, a new classification of SAXCAB grafting is proposed depending on whether the graft is inside or outside the rib cage and whether or not the coronary artery is exposed by rib resection or through an intercostal space. The third part of the classification takes into consideration the mode of entry into the chest, whether it is by rib resection or through an intercostal space.

Inquiries were made by telephone and by mail in the year 2000 to a number of surgeons who had published details of their SAXCAB techniques, and informal information was obtained by a series of personal communications as to the estimated number of operations they had performed and the outcomes. Published data was also used to formulate a rough guide as to the international status of the procedure at this time.

The total estimated international experience is about 100 cases and the patency is between 70 and 100 percent in the time frame of about one to two years.

The MIDCAB technique in general has been successful in providing an alternative way to revascularize the coronary arteries, and the SAXCAB has proved to be one of the most interesting classes of MIDCAB surgery. SAXCAB grafts seem to be unique among coronary revascularization procedures and, indeed, probably almost all vascular procedures, in that there is enormous diversity in the route for the graft from the inflow source to the target coronary artery. Being knowledgeable about the different varieties of SAXCAB surgeries will help the surgeon during a rescue operation as the surgery can be tailored to suit a particular patient. The SAXCAB seems to be a very safe operation, and it is striking that so far no one has reported any major complications.