Retrograde arterial perfusion, not incision location, significantly increases the risk of stroke in reoperative mitral valve procedures

Background: A recent report suggested that a thoracotomy approach for reoperative mitral valve (MV) procedures was associated with an equivalent mortality and an unacceptable risk of stroke. We assessed these outcomes in a single institution's experience.

Methods: From 1992 through 2007, 905 patients underwent reoperative MV procedures. The approach was a median sternotomy in 612 (67.6%), right anterior thoracotomy in 242 (26.7%), and left posterior thoracotomy in 51 (5.6%). Concomitant procedures in 411 patients (67.6%) included aortic procedures in 189, tricuspid procedures in 170, and coronary artery bypass grafting in 90. Hypothermic fibrillation was used in 65 patients. Logistic analysis was used to analyze risk factors and outcomes.

Results: Overall mortality was 12.7% (115 of 905), 6.7% (25 of 371) for first time isolated MV reoperations, and 10.1% (50 of 494) for all isolated MV operations. Overall incidence of stroke was 3.8% (34 of 905); 10.9% (9 of 82) with retrograde arterial perfusion and 3.0% (25 of 824) with central aortic cannulation (p < 0.001). For isolated MV reoperations, the incidence of stroke was 4.3% (21 of 494): 2.9% (7 of 241) for antegrade perfusion and 5.5% (14 of 253) for retrograde perfusion (p = 0.15). Risk factors for death were age (p < 0.001), renal failure (p < 0.01), tricuspid valve disease (p < 0.001), chronic obstructive pulmonary disease (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.8 to 4.9; p < 0.001), emergency procedure (OR, 2.9; 95% CI, 1.2 to 6.9; p = 0.02), and ejection fraction less than 0.30 (OR, 1.9; 95% CI, 1.1 to 3.3, p = 0.018). Risk factors for stroke were retrograde perfusion (OR, 4.4; 95% CI, 1.8 to 10.3; p < 0.01) and ejection fraction below 0.30 (OR, 2.1; 95% CI, 0.9 to 5.0; p = 0.09).

Conclusions: The incidence of stroke in reoperative MV operations is associated with perfusion strategies, not with the incisional approach. Reoperative sternotomy and minithoracotomy with central cannulation are both useful for reoperative MV procedures and are associated with low stroke rates.