Methods
This is a single centre, retrospective study. Data for re-sternotomy for AVR with or without another concomitant cardiac procedure were retrospectively collected from 2000 – 2019 from the hospital database (Patient Administration System, e-CAMIS, Yeadon, Leeds, UK). All patients with previous CABG who had re-sternotomy for AVR with or without another concomitant cardiac procedure were included. Emergency/salvage operations and infective endocarditis were excluded. Approval was obtained from the institutional review committee. Consent for individual use of data was waived due to the nature of the study and prior approval for use of such data at the time of consent for procedures.
Baseline demographic characteristics included variables used for risk stratification as previously defined for EuroSCORE (table 1). Data for previous operations was collected for number of previous sternotomies, type of previous surgery, left internal mammary artery (LIMA) use and patency and presence of other grafts. Operative and postoperative data included type and extent of surgery, injury to cardiac structures at re-sternotomy, myocardial protection, cross clamp time, total bypass time, re-exploration for bleeding/tamponade, new postoperative transient ischemic attack (TIA)/stroke, new hemofiltration, deep sternal wound infection, in-hospital mortality (death before hospital discharge) and length of stay (number of days from the date of operation to discharge).
The standard procedure of re-sternotomy at our institution was followed. The strategy of peripheral cannulation prior to re-sternotomy was based on surgeon preference and perceived risk of injury at re-entry. All re-sternotomies were performed with an oscillating saw. All cardiac injuries and catastrophic bleeding at re-entry were dealt with standard protocols. For patent LIMA, a strategy of endovascular balloon occlusion or isolation and clamping after re-sternotomy was employed. Myocardial protection was achieved with cold blood antegrade or retrograde cardioplegia with use of mild to moderate systemic hypothermia.