Background and aim of the study: Aortic valve replacement (AVR) with stentless bioprostheses offers superior hemodynamics. In order to overcome the disadvantages of older, stentless valves, a new generation of pericardial stentless prostheses has been developed. Herein, the hemodynamic and clinical results of these substitutes have been evaluated.
Methods: Between March 2002 and May 2004, 85 patients (59 females, 26 males; mean age 73.6 ± 6.1 years) who underwent AVR received either a bovine (Sorin Pericarbon Freedom®; SPF; n = 50) or an equine (3F Aortic Bioprosthesis®; 3F; n = 35) pericardial stentless valve. Patients were followed up prospectively at six months after surgery by clinical and echocardiographic examination. The mean follow up period was 5.6 ± 0.8 months, and was 96.4% complete.
Results: Mortality was 2.4% at 30 days (two SPF patients; one died at reoperation for suspected valve thrombosis and one was a non-valve-related death) and 2.5% at follow up (two SPF patients; both non-valve-related). Neither structural valve failure nor

endocarditis were observed. Preoperatively, there were no differences in baseline data, functional status and hemodynamics between SPF and 3F patients. The aortic cross-clamp time was similar in both groups (51.7 ± 11.2 min for SPF; 51.6 ± 8.2 min for 3F). NYHA functional status improvement was similar in each group (1.8 ± 0.5 for SPF; 1.7 ± 0.6 for 3F). The mean transaortic pressure gradient (Dpmean) was reduced in all patients during follow up. With SPF, a lower Dpmean was found for smaller aortic roots (indexed annular diameter (IAD) <14 mm/m2) as well as in larger (IAD ≥14 mm/m2) aortic roots: 8.0 ± 4.5 mmHg versus 13.2 ± 7.2 mmHg (p <0.05) and 6.8 ± 3.0 mmHg versus 12.8 ± 4.8 mmHg (p <0.05), respectively.
Conclusion: New-generation pericardial stentless aortic valves are very pliable, which facilitates their implantation. Clinical and hemodynamic results with these prostheses are promising. The SPF prosthesis demonstrates excellent performance, and may be superior when implanted in small aortic roots.

The Journal of Heart Valve Disease 2005;14:623-629