Stentless vs Stented Aortic Valve Bioprostheses in the Small Aortic Root

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Prosthetic Valve Design

Background:

• Aortic valve replacement (AVR) in patients with small aortic roots presents challenges.
• Stentless bioprostheses may offer advantages over stented designs in these cases.

Purpose of the Study:

• To compare the clinical and echocardiographic outcomes of the stentless Freedom SOLO bioprosthesis versus a stented Mitroflow bioprosthesis in patients with small aortic roots undergoing AVR.

Main Methods:

• Retrospective comparison of 269 consecutive patients undergoing AVR with either Freedom SOLO (n=76) or Mitroflow (n=193) bioprostheses (sizes 19-21mm).
• Clinical and echocardiographic data were collected and analyzed for mid-term follow-up (up to 7 years).

Main Results:

• Operative outcomes and survival were similar between groups.
• Freedom SOLO showed significantly lower peak and mean valvular gradients (P<0.001) and less prosthesis-patient mismatch (28% vs 52%, P=0.001).
• At 7 years, Freedom SOLO favored lower rates of reoperation (0% vs 7.1%, P=0.03) and structural valve deterioration (0% vs 4.5%, P=0.08).

Conclusions:

• The stentless Freedom SOLO bioprosthesis demonstrates superior hemodynamic performance and durability in patients with small aortic roots compared to the stented Mitroflow prosthesis.
• Lower valvular gradients, reduced prosthesis-patient mismatch, and improved valve durability favor the Freedom SOLO for AVR in this specific patient population.