The CarboMedics 'Top-Hat' aortic valve prosthesis: short-term results.

BACKGROUND AND AIM OF THE STUDY: The CarboMedics 'Top-Hat' aortic valve prosthesis has been specifically designed for supra-annular implantation. The aim of this study was to assess the safety of implantation of this prosthesis by reporting the short-term results of follow up. METHODS: Between May 1993 and May 1998, 128 patients (mean age 62.5 +/- 9.8 years; range: 22-76 years) received a CarboMedics 'Top-Hat' prosthesis at our institution. Among patients, 55% were in NYHA functional classes III or IV, and 54.7% had an isolated aortic valve replacement. Associated procedures were: coronary artery bypass grafting (25.7%), double valve replacement (17.1%), treatment of ascending aortic aneurysm (4.7%) and miscellaneous (5.5%). Follow up was 100% complete; total cumulative follow up was 265 patient-years (pt-yr) (range: 2-60 months). RESULTS: The overall mortality rate was 1.5% (two deaths). The operative mortality rate was 0.8% (one death); this patient died from neurological complications after operation for aortic dissection. The other patient died on postoperative day 40 from a massive cerebral hemorrhage. Four patients presented thromboembolic events; in all cases these were reversible ischemic neurologic deficits. One patient had a nonstructural deterioration (endocarditis) and required reoperation. Freedom from mortality was 98.3% at five years (linearized rate of 0.75%/pt-yr). Freedom from thromboembolism was 63.1% at five years (linearized rate 1.5%/pt-yr). CONCLUSION: Short-term results with the CarboMedics 'Top-Hat' prosthesis were satisfactory, with low rates of morbidity and mortality. As this prosthesis has demonstrated a good reliability to date, we have continued its implantation in our institution, and long-term follow up will be necessary to confirm these good early results.

Doppler-echocardiographic assessment of the carbomedics supra-annular 'Top-Hat' prosthetic heart valve in the aortic position.

Twenty-one CarboMedics 'Top-Hat' bileaflet prostheses were implanted in the aortic position between May 1993 and May 1994 at our institution. Valve performance was assessed by repeat echocardiography. We found it very easy to implant this prosthesis even in the small aortic annulus and it allowed us to implant a valve that is at least one size larger than implantation in the intra-annular position allows. The only contraindication to the implantation of this prosthesis is when the coronary ostia are displaced downwards, which would apply to any supra-annular prosthesis. The Doppler echocardiographic assessment showed acceptable transvalvular gradients and velocity indexes. The Top-Hat prosthesis is now our valve of choice in the small aortic annulus.