Impact of some intraoperative factors on wound infection in cardiac surgery

Abstract

Relevanc. Surgical Site Infection (SSI) after open heart surgery is a significant problem in clinical, social, and economic aspect which causes the need to identification of the preferred procedures for successful prevention of the SSI.Objectives. To determine risk of the SSI in cardiac surgery depending on complexity of intervention, using of cardiopulmonary bypass (CBP) and use of both internal mammary arteries (IMA).Methods. Prospective observations study from 2010 to 2019 in cardiac surgery department of the Ural Institute of Cardiology, where in total 4993 open heart surgery procedures were consecutively performed. All SSI cases were recorded up to 90 days after surgery. The analysis was performed to identify risk of cardiopulmonary bypass (CPB), bilateral IMA grafting and combined procedures on the risk of the postoperative wound infection.Results. During the investigation period, total 220 cases of the SSI (4,5%) have been registered of the 4993 patients undergoing open heart surgery. It included 42 cases of deep sternal infection (0,9%) and 178 cases of superficial infection (3,6%). The main pathogen identified was Staphylococcus epidermidis (56,4%). During the hospital period, 151 cases (66,5%) of SSI have been detected, with the median time to detection of the complication 6 days. The relative mortality risk in deep sternal infection group was 4,4 times higher than in the group without SSI (HR 4,6, 95 % CI 1,5-13,9, p=0,003624). CABG increases the relative risk of SSI in compare with non-CABG procedures (OR 3,086169; 95%CI 1,281 – 7,437), while the complexity of the operation (combined versus isolated interventions) does not significantly increase the risk (OR 0.972283; 95% CI: 0.696 - 1.359). The incidence of SSI in the group of in situ BIMA grafting was 8.8%, significantly increasing the likelihood of the SSI in compare to those with SIMA (OR 2.167983, 95% CI 1.463 - 3.212; p =0,000057). CBP significantly increases the risk of postoperative wound infections (OR 1.523890, 95% CI 1.149 - 2.022, p = 0.001742).Conclusions. Refusal of cardiopulmonary bypass, simultaneous procedures and bilateral coronary artery bypass does not allow completely to avoid postoperative wound infections. Nevertheless, the technical features of the preparations and use of grafts, including skeletonization, prevention of coagulation and the preference for sequential composite CABG, can reduce the risk associated with the type of the open heart surgery.