BACKGROUND: Deep sternal wound infection (mediastinitis) occurred in 21 out of 4043 consecutive patients who underwent a cardiopulmonary bypass procedure (incidence of 0.4%). METHODS: Clinical characteristics of patients who developed mediastinitis (group I) were compared to those of patients who had no mediastinal infection (group II). RESULTS: Hospital mortality was significantly higher in group I (14% vs 3.8%) (p<0.001). Mean hospital stay was longer in group I (36 days vs 7 days) (p<0.001). Multivariate analysis identified the following variables as significant risk factors for developing postoperative mediastinitis: diabetes; relative risk (RR)=3.02, 95% confidence limits (CL)=1.68-5.45, resternotomy for bleeding: RR=5.43, CL=1.85-15.92, associated leg wound infections; RR=16.55, CL=5.32-51.49, the need for 3 or more units of blood transfusion; RR=2.48, CL=1.82-3.39, obesity; RR 4.96, CL 2-12.25. Group I patients were categorised according to a recently proposed classification for mediastinitis (reference 1). Type I (n=17), mediastinitis presenting within 2 weeks following surgery in the absence of risk factors. Type II (n=2), mediastinitis presenting at 2-6 weeks following surgery in the absence of risk factors. Type IIIA (n=2), mediastinitis type I in the presence of one or more risk factor(s). Wound debridement and closed mediastinal irrigation was performed in 19 patients; 15 cases with type I, 2 with type II, and 2 with type IIIA. Primary closure without irrigation was performed in 2 type I patients. The primary intervention failed in 3 patients, two of whom died. A third patient died 4 weeks after an apparently successful treatment of type I mediastinitis. Midterm follow-up (mean of 18 months) of 18 patients showed that 16 patients were alive and well, there was one late death, and one patient had chronic wound pain. CONCLUSION: Diabetes, obesity, associated leg-wound infection, and the need for repeated blood transfusions are associated with high risk of mediastinitis. Closed mediastinal irrigation for mediastinitis type I can yield satisfactory functional and cosmetic midterm results.
BACKGROUND: Deep sternal wound infection (mediastinitis) occurred in 21 out of 4043 consecutive patients who underwent a cardiopulmonary bypass procedure (incidence of 0.4%). METHODS: Clinical characteristics of patients who developed mediastinitis (group I) were compared to those of patients who had no mediastinal infection (group II). RESULTS: Hospital mortality was significantly higher in group I (14% vs 3.8%) (p<0.001). Mean hospital stay was longer in group I (36 days vs 7 days) (p<0.001). Multivariate analysis identified the following variables as significant risk factors for developing postoperative mediastinitis: diabetes; relative risk (RR)=3.02, 95% confidence limits (CL)=1.68-5.45, resternotomy for bleeding: RR=5.43, CL=1.85-15.92, associated leg wound infections; RR=16.55, CL=5.32-51.49, the need for 3 or more units of blood transfusion; RR=2.48, CL=1.82-3.39, obesity; RR 4.96, CL 2-12.25. Group I patients were categorised according to a recently proposed classification for mediastinitis (reference 1). Type I (n=17), mediastinitis presenting within 2 weeks following surgery in the absence of risk factors. Type II (n=2), mediastinitis presenting at 2-6 weeks following surgery in the absence of risk factors. Type IIIA (n=2), mediastinitis type I in the presence of one or more risk factor(s). Wound debridement and closed mediastinal irrigation was performed in 19 patients; 15 cases with type I, 2 with type II, and 2 with type IIIA. Primary closure without irrigation was performed in 2 type I patients. The primary intervention failed in 3 patients, two of whom died. A third patient died 4 weeks after an apparently successful treatment of type I mediastinitis. Midterm follow-up (mean of 18 months) of 18 patients showed that 16 patients were alive and well, there was one late death, and one patient had chronic wound pain. CONCLUSION:Diabetes, obesity, associated leg-wound infection, and the need for repeated blood transfusions are associated with high risk of mediastinitis. Closed mediastinal irrigation for mediastinitis type I can yield satisfactory functional and cosmetic midterm results.