Does use of a right internal thoracic artery increase deep wound infection and risk after previous use of a left internal thoracic artery?

To determine whether adding right internal thoracic artery to previous left internal thoracic artery bypass at reoperation increases deep sternal wound infection and hospital mortality, particularly in diabetic patients.

Reoperations (n = 2875; 2381 men) in patients with previous left internal thoracic artery bypass were performed between January 1990 and January 2003; 1939 (67%) had no repeat internal thoracic artery grafting, 923 (32%) received an additional right internal thoracic artery graft, and 13 (0.5%) had bilateral internal thoracic artery grafting with reuse of the left internal thoracic artery. Of the patients, 352 (12%) were insulin-treated and 590 (21%) non-insulin-treated diabetics. Multivariable logistic regression analysis was used to identify preoperative variables associated with right versus non-right internal thoracic artery use in diabetics and nondiabetics and to formulate propensity models. Propensity scores were used for matching and adjusted multivariable analyses of deep wound infection and hospital mortality.

Deep wound infection occurred in 3.0% (7/230) of diabetics receiving right internal thoracic artery grafts, 2.2% (5/230) of propensity-matched diabetics receiving non-right internal thoracic artery grafts (P = .6), in 1.1% (6/538) of nondiabetics receiving right internal thoracic artery grafts, and in 1.0% (5/538) of matched non-diabetic patients receiving non-right internal thoracic artery grafts (P = .8). Corresponding hospital mortality in these matched groups was 1.7% (4/230) versus 6.1% (14/230) for diabetics (P = .02) and 2.6% (14/538) versus 3.5% (19/538) for nondiabetics (P = .4). Risk factors for deep wound infection included higher weight (P = .0003), higher New York Heart Association functional class (P = .03), and less severe left anterior descending disease (P = .03). Risk factors for death were (P < .02) emergency operation, mitral valve replacement, and greater number of saphenous vein grafts.

Use of the right internal thoracic artery for reoperations does not increase the risk of deep wound infections in diabetics or nondiabetics and does not increase mortality.