Aortic root replacement with stentless xenografts in patients with aortic stenosis

Objective: Stentless bioprosthetic valves such as the Freestyle conduit have been widely used as an option for aortic root replacement in the setting of aortic root aneurysms with acceptable long-term outcomes. However, there is a paucity of data regarding the use of the Freestyle prosthesis in patients with aortic stenosis. Methods: All patients with a primary diagnosis of severe aortic stenosis who underwent complete aortic root replacement with Freestyle conduits were included. Primary outcomes included survival and readmissions for heart failure. Secondary outcomes included immediate postoperative complications. Results: In total, 2529 patients with severe aortic stenosis who needed an open aortic valve replacement with a biological prosthesis were operated on between 2011 and 2017. Of these, 294 patients underwent aortic root replacements using the Freestyle conduit with a primary diagnosis of native or prosthetic aortic stenosis. Eighty-four (28.6%) of the patients underwent reoperative sternotomy. The majority (53.7%) of the cohort were men. The mean age was 67.5 +/- 13.0 years. Mean Society of Thoracic Surgeons Predicted Risk of Mortality when calculated with the assumption of aortic valve replacement +/- coronary artery bypass grafting was 8.10% +/- 10.8. The median follow-up time for the entire group was 2.7 years (interquartile range 0.9-4.5 years). Operative (30-day) mortality was 7.1% (n = 21). Kaplan-Meier mortality estimates at 1 and 5 years are 16.6% and 27.6%, respectively. Mean gradients were 7.15 +/- 4.47 mm Hg at 1 month and 6.32 +/- 4.76 mm Hg at 1 year. Readmissions for heart failure at 30 days, 1 year, and 5 years were 5.6%, 11.8%, and 17.4%, respectively. Conclusions: Aortic root replacement using Freestyle bioprostheses is a viable option for patients with severe aortic stenosis with low risk of hospital readmission for heart failure.