Deep sternal wound infection is one of the most serious postoperative complications after median sternotomy and it has a relatively high mortality. This has motivated numerous research groups to evaluate in detail the clinical profiles of patients with DSWI as well as to explore the predictive factors that may presage this pathology. In this context, the influence of DSWI on in-hospital and short-term mortality was one of the most intensively discussed subjects in the past [1
]. It seems that preoperative as well as intra-operative predictive factors were well identified. However, most risk factors for DSWI are not amenable to modification [7
]. In order to reduce the incidence of DSWI, different preventive measures were undertaken. For example, in patients with diabetes mellitus, tight control of blood sugar level reduced the incidence of DSWI [8
], and use of skeletonized mammary artery also significantly contributed to reduction of this complication [9
]. Although the characteristics of DSWI were well explored, long-term survival and mortality profile of the patients having DSWI after hospital admission has not been sufficiently described and evaluated. To the best of our knowledge, few reports in the literature have discussed mid-term or long-term results following DSWI [10
In the present study, a follow-up of more that 10 years was executed by phone calls to the patients and their personal physicians. Information regarding mortality and complications during this period were obtained. Incidence of DSWI was 1.56%, with perioperative mortality of 8.1%; both results are comparable to results published in the literature, in which the incidence of DSWI is reported to be between 1.5% and 3%, with a perioperative mortality ranging from 15% to 30% [10
]. Out of 74 patients, a cardiac cause of death was presented in 5 patients and sepsis was presented in 4 cases. In 1 case with cardiac cause of death, laceration of the right ventricle was the cause of death. In the 3 remaining cases, cardiac failure was the reason for death.
In long-term survival, there was no difference between groups. The total mortality was 27% in the DSWI group and 21.6% in the controls (p=0.57), which actually corresponds to the long-term mortality after open heart surgery [14
]. Mortality due to a cardiac event was not significantly different in the 2 groups investigated: 15% in DSWI and 11% in controls. This result corresponds to the reports published in which the impact of DSWI following cardiac surgery was evaluated over a period of 8 years [12
]. Thirty-day mortality was also elevated in the DSWI group – 7.3% vs.
1.6% in the control group [15
]. No further differences in 4-year and 8-year survival rate between the 2 groups were found (77.2% and 61.8%, respectively, in patients with DSWI, as compared with 78.0% and 67.5%, respectively, in patients without DSWI) [15
]. Consistent with results reported by Cayci et al. [16
], DSWI did not influence the long-term survival in the present population.
However, we have to be aware that this statement is only true after the perioperative period passed. This can also be seen in the Kaplan Meier curve, where the survival between the 2 groups is parallel after the perioperative period. This means that the in-hospital period for patients is critical, with elevated mortality. If this phase is successfully survived, their life expectancy does not differ from that of patients without DSWI. Reasons for in-hospital mortality in the DSWI group are multifactorial.
The in-hospital mortality was 7%, which is about 3 times higher than in the in-patient population without DSWI. In the majority of cases, it was a consequence of septicemia and/or multi-organ failure. In addition to the septic events, repeated surgical revision with change of VAC systems may contribute to elevated mortality. Repeated surgical revisions are earmarked by repeated surgical trauma, which clearly increases perioperative stress. Debridement and occasional sternal bone fractures due to infection, as well as debridement and repeated surgical manipulation with VAC system, may contribute to laceration and perforation of the right ventricle. This was also a case in our series.