Efficacy of Stentless Aortic Bioprosthesis Implantation for Aortic Stenosis with Small Aortic Annulus

Abstract

Background In patients with small aortic annulus, sufficient size of stented aortic bioprosthesis cannot be implanted without additional procedures. In such cases, we use stentless aortic bioprosthesis to obtain sufficient effective orifice area. In this study, we investigated long-term impact of stentless aortic bioprosthesis on clinical outcomes, compared with stented aortic bioprosthesis.

Materials and Methods We retrospectively investigated 140 patients who underwent aortic valve replacement (AVR) with porcine bioprosthesis for severe aortic stenosis between 1999 and 2010. Patients who had moderate or more aortic regurgitation and who underwent concomitant mitral procedures were excluded. A total of 69 patients (49%) were implanted stentless bioprosthesis (Freestyle group; Medtronic Inc, Minneapolis, Minnesota, United States) and 71 patients (51%) were implanted stented bioprosthesis (Mosaic group; Medtronic Inc). Follow-up was complete in 97.9% patients. Median follow-up period was 4.2 years.

Results Patients in Freestyle group had smaller body surface area, smaller aortic annulus diameter, smaller aortic valve area, larger mean pressure gradient, higher peak velocity across aortic valve, larger left ventricular mass index (LVMI), and lower left ventricular ejection fraction (LVEF). Mean size of implanted prosthesis was larger in Freestyle group. In-hospital mortality was 1.4% in Freestyle group and 2.8% in Mosaic group (p = 0.980). Five-year survival rate was not different between two groups (5-year survival rate was 87.5 ± 4.7% in Freestyle group and 84.1 ± 7.5% in Mosaic group; log rank, p = 0.619). Late New York Heart Association functional class was lower in Freestyle group. Late LVMI and LVEF became similar between two groups.

Conclusion Stentless aortic bioprosthesis is superior in left ventricular remodeling after AVR for aortic stenosis and is especially effective for small aortic annulus.

Keywords

aortic valve and root - heart valve surgery - clinical outcomes

• References

• 1 Rahimtoola SH. The problem of valve prosthesis-patient mismatch. Circulation 1978; 58 (1) 20-24
• 2 Konno S, Imai Y, Iida Y, Nakajima M, Tatsuno K. A new method for prosthetic valve replacement in congenital aortic stenosis associated with hypoplasia of the aortic valve ring. J Thorac Cardiovasc Surg 1975; 70 (5) 909-917
• 3 Manouguian S, Seybold-Epting W. Patch enlargement of the aortic valve ring by extending the aortic incision into the anterior mitral leaflet. New operative technique. J Thorac Cardiovasc Surg 1979; 78 (3) 402-412
• 4 Nicks R, Cartmill T, Bernstein L. Hypoplasia of the aortic root. The problem of aortic valve replacement. Thorax 1970; 25 (3) 339-346
• 5 Cohen G, Christakis GT, Joyner CD , et al. Are stentless valves hemodynamically superior to stented valves? A prospective randomized trial. Ann Thorac Surg 2002; 73 (3) 767-775 , discussion 775–778
• 6 Fries R, Wendler O, Schieffer H, Schäfers HJ. Comparative rest and exercise hemodynamics of 23-mm stentless versus 23-mm stented aortic bioprostheses. Ann Thorac Surg 2000; 69 (3) 817-822
• 7 Morsy S, Zahran M, Usama M, Elkhashab K, Abdel-Aziz I. Hemodynamic performance of stentless porcine bioprosthesis and mechanical bileaflet prosthesis using dobutamine stress echocardiography. Semin Thorac Cardiovasc Surg 2001; 13 (4, Suppl 1): 129-135
• 8 Mohammadi S, Tchana-Sato V, Kalavrouziotis D , et al. Long-term clinical and echocardiographic follow-up of the Freestyle stentless aortic bioprosthesis. Circulation 2012; 126 (11, Suppl 1): S198-S204
• 9 Doty DB, Cafferty A, Kon ND, Huysmans HA, Krause Jr AH, Westaby S. Medtronic Freestyle aortic root bioprosthesis: implant techniques. J Card Surg 1998; 13 (5) 369-375
• 10 Bach DS, Kon ND, Dumesnil JG, Sintek CF, Doty DB. Ten-year outcome after aortic valve replacement with the freestyle stentless bioprosthesis. Ann Thorac Surg 2005; 80 (2) 480-486 , discussion 486–487
• 11 O'Brien SM, Shahian DM, Filardo G , et al; Society of Thoracic Surgeons Quality Measurement Task Force. The Society of Thoracic Surgeons 2008 cardiac surgery risk models: part 2—isolated valve surgery. Ann Thorac Surg 2009; 88 (1, Suppl): S23-S42
• 12 Tasca G, Mhagna Z, Perotti S , et al. Impact of prosthesis-patient mismatch on cardiac events and midterm mortality after aortic valve replacement in patients with pure aortic stenosis. Circulation 2006; 113 (4) 570-576
• 13 LaPar DJ, Ailawadi G, Bhamidipati CM , et al. Small prosthesis size in aortic valve replacement does not affect mortality. Ann Thorac Surg 2011; 92 (3) 880-888 , discussion 888
• 14 Ruel M, Al-Faleh H, Kulik A, Chan KL, Mesana TG, Burwash IG. Prosthesis-patient mismatch after aortic valve replacement predominantly affects patients with preexisting left ventricular dysfunction: effect on survival, freedom from heart failure, and left ventricular mass regression. J Thorac Cardiovasc Surg 2006; 131 (5) 1036-1044
• 15 Mazzola A, Di Mauro M, Pellone F , et al. Freestyle aortic root bioprosthesis is a suitable alternative for aortic root replacement in elderly patients: a propensity score study. Ann Thorac Surg 2012; 94 (4) 1185-1190
• 16 Westaby S, Horton M, Jin XY , et al. Survival advantage of stentless aortic bioprostheses. Ann Thorac Surg 2000; 70 (3) 785-790 , discussion 790–791
• 17 Borger MA, Carson SM, Ivanov J , et al. Stentless aortic valves are hemodynamically superior to stented valves during mid-term follow-up: a large retrospective study. Ann Thorac Surg 2005; 80 (6) 2180-2185