Impact on Mechanical Properties of 10 versus 20 Minute Treatment of Human Pericardium with Glutaraldehyde in OZAKI Procedure

Tissue requirements for the application of aortic valve neocuspidization - appropriate pericardium properties and homogeneity?

OBJECTIVE

Aortic valve neocuspidization (AVNeo) using autologous pericardium is a promising technique. Expected advantages are reduced immune response, appropriate biomechanics and lower treatment expenses. Nevertheless, autologous pericardium can be affected by patient's age and comorbidities. Usually, glutaraldehyde (GA) - fixed bovine pericardium is the basic material for aortic valve prostheses, easy available and carefully pre-examined in a standardized fabrication process. Aim of the study is the verification of autologous pericardial tissue homogeneity by analysing tissue thickness, biomechanics and extracellular matrix (ECM) composition.

METHODS

Segments of human GA-fixed pericardium selected by the surgeon based on visual criteria for cusp pre-cut and remaining after surgical AV replacement were investigated in comparison to bovine standard tissue treated equivalently. Pericardium sampling was performed at up to three positions of each sutured cusp for histological or biomechanical analysis, according to tissue availability.

RESULTS AND CONCLUSIONS

Human pericardia exhibited a higher heterogeneity in collagen content, density of vessel structures and elastic moduli. Thickness, vessel density and collagen and elastin content differed significantly between the species. In contrast, significant interindividual differences were detected in most properties investigated for human pericardial samples but only for tissue thickness in bovine tissues. Higher heterogeneity of human pericardium, differing vessel and collagen content compared to bovine state-of-the-art material might be detrimental for long term AV functionality or deterioration and have to be intensely investigated in patients follow up after autologous cusp replacement.

Aortic Valve Neocuspidization Using Autologous Pericardium (Ozaki Procedure): an Alternative to Aortic Valve Replacement in Adult Cardiac Surgery?

Purpose of the Review

The aim of this article is to describe the technique of aortic valve neocuspidization using autologous pericardium (AVNeo, “OZAKI procedure”) in adult cardiac surgery, to analyze recent findings, and to discuss benefits and limitations of this technique.

Recent Findings

Potential benefits of this technique include excellent hemodynamic performances, minimal use of foreign material, low rates of permanent pacemaker implantation, and omission of oral anticoagulation. However, data regarding the durability of the procedure are hitherto limited, and the procedure is associated with a higher complexity compared to aortic valve replacement.

Summary

AVNeo using autologous pericardium in adult cardiac surgery is a promising technique providing several benefits. However, there is a major unmet need for more data, especially regarding long-term durability. Thus, based on currently available data, we recommend careful patient selection within the heart team and shared decision-making with the informed patient.