• Interventional Techniques & Devices

Edward B. Savage, MD, Cleveland Clinic Florida, Weston, Florida, USA, reviewed the facts that support multiarterial bypass grafting, discussed complications, and reviewed circumstances for favorable outcomes.

The left internal thoracic artery (LITA) is universally accepted as the best conduit for the left anterior descending artery in coronary artery bypass graft surgery (CABG) and is routinely used in over 90% of CABG procedures [Tatoulis J et al. Ann Thorac Surg 2011]. It reduces morbidity and mortality compared with the use of saphenous vein grafts (SVGs) [Slaughter MS. Circulation 2011].

To date, only the benefit of the single internal thoracic artery (SITA) has been proven by randomized trials. However, observational studies on the use of bilateral ITA (BITA) have shown similar improved outcomes when compared with LITA and SVG. Likewise, a recent propensity score-matched trial of concomitant radial artery (RA) versus second ITA in 1001 CABG patients found significant overall survival (p=0.022) and major cardiac and cerebrovascular event-free survival (p<0.001) using the ITA rather than RA grafts [Ruttman E et al. Circulation 2011].

Even more recently, Galbut et al. [J Thorac Cardiovasc Surg 2012] demonstrated that broadly applied BITA compared with SITA grafting in propensity-matched patients provides enhanced long-term survival with no increase in operative mortality or morbidity for patients with normal and reduced ejection fraction.

Still, multiple arterial revascularization is performed in <13% of CABG procedures, with the RA most commonly used as the second conduit of choice [Ruttman E et al. Circulation 2011]. According to Slaughter [Circulation 2011], this is of concern given the known limitations of the RA, including susceptibility to vasospasm, potential calcification and poor quality in elderly patients, and the need for a proximal anastomosis with a small diameter conduit.

The right ITA (RITA), though biologically identical to the LITA, has been used less often [Tatoulis J et al. Ann Thorac Surg 2011]. Many institutions and cardiac surgeons either never or infrequently use the RITA in CABG. Reasons that RITA is used less frequently may include additional time to harvest, concerns over deep sternal wound infection, myocardial hypoperfusion, unfamiliarity, lack of randomized trials, and insufficient patency data [Tatoulis J et al. Ann Thorac Surg 2011].

After a study of 5766 patients and 991 angiograms, Tatoulis et al. [Ann Thorac Surg 2011] found evidence to reconsider RITA. Late patencies of RITA were excellent, equivalent to LITA for identical territories, always better than RAs (p<0.01) and SVGs (p<0.001), and remained free of atheroma. Use of RITA in addition to LITA was associated with excellent survival in triple vessel coronary disease (10-year survival, 89%).

According to Dr. Savage, impediments to the use of multiarterial grafting include higher incidence of sternal wound infection; longer duration of surgery; and increased technical difficulty, especially with branched grafts. However, each additional ITA used improves survival and freedom from major adverse cardiac and cerebrovascular events, and skeletonization of the ITA reduces risk of wound infection. He reported that for most patients, multiarterial grafting improves long-term outcomes without significantly increasing perioperative risk.

• © 2012 MD Conference Express®