Identifying patients at particular risk of injury during repeat sternotomy: Analysis of 2555 cardiac reoperations

Objectives: A variety of protective strategies during repeat sternotomy been proposed; however, it remains unclear for which patients they are warranted. Methods: We identified adults undergoing repeat median sternotomy for routine cardiac surgery at our institution between January 1, 1996, and December 31, 2007. The operative notes and perioperative outcomes were reviewed. Results: Of the 2555 patients, 1537 (60%) had undergone previous coronary artery bypass grafting, 700 (27%) previous mitral valve surgery, and 643 (25%) previous aortic valve replacement (AVR). Sixty-one patients (2%) had prior mediastinal radiotherapy, and 424 (17%) had more than one previous sternotomy. In 231 patients, 267 injuries (9.0%) occurred. Injury occurred during sternotomy in 87 patients (33%) and during prepump dissection in 135 (51%). The hospital mortality rate was 6.5% among those without injury and 18.5% among those with injury (P < .001); when injury occurred during sternal division, the mortality rate was 25%. Injuries were more common after previous coronary artery bypass grafting (11% with previous coronary artery bypass grafting vs 7% without, P = .0012) but not previous AVR, mitral valve surgery, or aortic surgery. Injury was also more common when the current operation was AVR (10% with AVR vs 8% without, P = .04) or aortic surgery (14% vs 8%, P = .004). On multivariate analysis, previous radiotherapy (odds ratio, 4.9), a greater number of previous sternotomies (odds ratio 1.7), and a patent internal thoracic artery (odds ratio, 1.8) predicted injury. Injury was an independent risk factor of hospital death (odds ratio, 2.6). Conclusions: Particular attention to protective strategies should be considered during reoperative sternotomy among patients with multiple previous sternotomies, previous mediastinal radiotherapy, and those with patent internal thoracic artery grafts. (J Thorac Cardiovasc Surg 2010;140:1028-35)