A new clinical classification and reconstructive strategy for post-sternotomy surgical site infection

INTRODUCTION: Post-sternotomy surgical site infection (SSI) is a serious complication of cardiovascular surgery. Here, we proposed a new clinical classification and reconstructive strategy for this condition. METHODS: A retrospective study based on medical records was performed on 100 consecutive cases requiring wound management by plastic surgeons for post-sternotomy SSI at Kobe University Hospital between January 2009 and December 2021. We classified 100 cases into four categories according to the anatomical invasiveness of the infection (type 1, superficial SSI; type 2, sternal osteomyelitis; type 3, mediastinitis; and type 4, aortic graft infection). The standard treatment plan comprised initial debridement, negative pressure wound therapy with continuous irrigation, and reconstructive surgery. Reconstructive methods and their outcomes (in-hospital mortality rate, follow-up period, and infection recurrence rate) were investigated for each SSI category. RESULTS: There were nine SSI cases in type 1, 28 in type 2, 25 in type 3, and 38 in type 4. The pectoralis major (PM) muscle advancement flap was mainly selected in types 1 and 2 (100 and 70.4%, respectively), while the omental flap or latissimus dorsi (LD) myocutaneous flaps were mainly selected in types 3 and 4 (77.3 and 81.8%, respectively) for reconstructive surgery. The in-hospital mortality rates for types 1, 2, 3, 4 were 44.4, 3.6, 12.0, and 15.8%, respectively. The mean follow-up periods for types 1, 2, 3, 4 were 542.8, 1514.5, 1154.5, and 831.1 days, respectively. Infection recurrence rates for types 1, 2, 3, 4 were 0, 11.5, 13.3, and 19.2%, respectively. All of these recurrent cases, except for 4 cases of type 4 that required surgical intervention, were treated with conservative wound management. CONCLUSION: A volume-rich flap (omental or LD flap) was required to fill the dead space after debridement in mediastinitis (type 3) or aortic graft infection (type 4), whereas superficial SSI (type 1) or sternal osteomyelitis (type 2) received a less-invasive flap (PM muscle advancement flap). Our new classification method was based on the anatomical invasiveness of the infection, providing both a simple and easy diagnosis and definitive treatment strategy.