MANAGEMENT OF THE INFECTED MEDIAN STERNOTOMY WOUND WITH MUSCLE FLAPS - THE EMORY 20-YEAR EXPERIENCE

Objective The purpose of the study is to define those patient variable s that contribute to morbidity and mortality of median sternotomy woun d infection and the results of treatment by debridement and closure by muscle flaps. Background Infection of the median sternotomy wound aft er open heart surgery is a devastating complication associated with si gnificant mortality. Twenty years ago, these wounds were treated with either open packing or antibiotic irrigation, with a mortality approac hing 50% in some series. In 1975, the authors began treating these wou nds with radical sternal debridement followed by closure using muscle or omental flaps. The mortality of sternal wound infection has dropped to <10%. Methods The authors' total experience with 409 patients trea ted over 20 years is described in relation to flap choices, hospital d ays after sternal wound closure, and incidence rates of morbidity and mortality. One hundred eighty-six patients treated since January 1988 were studied to determine which patient variables had impact on rates of flap closure complications, recurrent sternal wound infection, or d eath. Variables included obesity, history of smoking, hypertension, di abetes, poststernotomy septicemia, internal mammary artery harvest, us e of intra-aortic balloon pump, and perioperative myocardial infarctio n and were analyzed using chi square tests, Fisher's exact tests, and multivariable logistic regression analysis. Results The mortality rate over 20 years was 8.1% (33/49). Additional procedures for recurrent s ternal wound infection were necessary in 5.1% of patients. Thirty-one patients (7.6%) required treatment for hematoma, and 11 patients (2.7% ) required hernia repair. Among patients treated since 1988, variables strongly associated with mortality were septicemia (p < 0.00001), per ioperative myocardial infarction (p = 0.006), and intra-aortic balloon pump (p = 0.0168). Factors associated with wound closure complication s were intra-aortic balloon pump (p = 0.0287), hypertension (p = 0.033 5), and history of smoking (p = 0.0741). Factors associated with recur rent infection were history of sternotomy (p = 0.008) and patients tre ated for sternal wound infection from 1988 to 1992 (p = 0.024). Mean h ospital stay after sternal wound reconstruction declined from 18.6 day s (1988-1992) to 12.4 days (1993-1996) (p = 0.005). To clarify managem ent decisions of these difficult cases, a classification of sternal wo und infection is presented. Conclusions Using the principles of sterna l wound debridement and early flap coverage, the authors have achieved a significant reduction in mortality after sternal wound infection an d have reduced the mean hospital stay after sternal wound closure of t hese critically ill patients. Further reductions in mortality will dep end on earlier detection of mediastinitis, before onset of septicemia, and ongoing improvements in the critical care of patients with multis ystem organ failure.