The CarboMedics “Top-Hat” supraannular prosthesis

Background. The CarboMedics “Top-Hat” supraannular prosthesis was designed to permit the implantation of a larger prosthesis. Methods. Between June 1993 and November 1996, 127 patients (average age, 61.8 ± 10.2 years) received a CarboMedics “Top-Hat” supraannular aortic prosthesis. The average follow-up was 15.7 months, and all surviving patients underwent echocardiographic study. This group is compared with 656 patients in whom a standard CarboMedics prosthesis was implanted and also with 2,927 patients who received other aortic prostheses. Results. Using the standard and the supraannular sizers, there was an average increase of one size in favor of the supraannular prosthesis: 18.9 ± 2.8 mm standard versus 20.8 ± 2.6 mm supraannular (p< 0.005). For each prosthesis size (19 to 23 mm), the body surface area of the patients in whom a CarboMedics supraannular prosthesis was implanted was significantly smaller than that in those who received a CarboMedics standard prosthesis or any other model. Hospital mortality was 3.9%, and late mortality was 5.5%. The actuarial survival was 86.5% ± 3.9% at 42 months. Conclusions. Using the CarboMedics supraannular prosthesis allows implantation of a larger prosthesis compared with the standard CarboMedics prosthesis or other models. This advantage is especially important in patients with a small aortic root.