Mediastinitis and Cardiac Surgery - an Updated Risk Factor Analysis in 10,373 Consecutive Adult Patients

Abstract

Background: Deep sternal wound infection (DSWI) remains a serious complication after cardiac surgery. New evolving techniques including the utilization of internal mammary arteries (IMA), beating heart procedures, and minimal invasive surgery (MIC) require an updated risk factor analysis to identify high risk patients in order to improve perioperative treatment. Methods: 10,373 consecutive patients receiving cardiac surgery between May 1996 and August 1999 were evaluated: 9,303 underwent full sternotomy whereas a minimally invasive (MIC) approach using partial sternotomy or lateral thoracotomy was used in 1,070 patients. DSWI was defined as the evidence of mediastinitis seen at reoperation along with one or more of the following: positive culture of mediastinal fluid, positive blood culture or temperature higher than 38 °C and/or leukocytosis. Results: The overall incidence of DSWI in the “full sternotomy” group was 1.44 % (134 of 9,303). Univariate risk factor analysis showed a significant influence of IMA use, ICU / IC treatment > 5 days, postoperative ventilator time ≥ 72 h, need for reexploration, diabetes, surgery time ≥ 180 min, assist device implantation (including use of IABP), peripheral vascular disease and increased body mass index. Multivariate analysis identified double IMA, ICU treatment > 5 days, single IMA, diabetes, reexploration and increased body mass as significant risk factors. No mediastinitis was observed in the MIC group. Conclusion: As DSWI is related to sternotomy, a MIC approach should be considered for patients at high risk for DSWI. IMA takedown as a pedicled graft should be especially avoided in patients with diabetes since the risk for postoperative mediastinitis is unacceptably high in this patient group.

Key words

Mediastinitis - Heart surgery - Diabetes - Risk factors

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