Invited commentary to: 4D-flow cardiac magnetic resonance for the assEssmeNt of AOrtic valve repair with OzAki TEchnique

In a study led by Pirola et al., published in the European Journal of Cardio-Thoracic Surgery, the primary objective was to conduct a thorough comparison of wall shear stress (WSS), utilizing 4D MRI, in patients undergoing aortic valve replacement (AVR) employing the Av Neo (Ozaki) technique and those opting for the conventional AVR [1]. Historically, AVR has stood as a fundamental treatment modality for aortic valve disease. However, due to potential complications associated with conventional AVR, there has been a growing interest in exploring alternative surgical techniques. One such is the Av Neo technique, introduced in 2007, which involves the use of autologous pericardium neo leaflets to replace aortic cusps. The central aim of this surgical approach is to replace the 3 aortic cusps with autologous pericardium, presenting a viable alternative to classical AVR [2]. The choice of valve replacement prosthesis and procedure remains a subject of continuous debate, especially with the emergence of transcatheter procedures. Computational fluid dynamics plays a pivotal role in deriving shear stress on the aortic wall (WSS) [3]. Past research has indicated a potential link between increased WSS and histological alterations in the aortic wall. Conversely, aortic root distensibility may influence the geometric orifice area and aortic valve kinematics, subsequently affecting the mechanical load on the aortic valve cusps. This study primarily aimed to compare the WSS of the ascending aorta in patients undergoing aortic valve neocuspidization versus those undergoing AVR with biological prostheses. In 2011, Ozaki et al. [4] published their technique involving the use of autologous pericardium, which was studied in a large patient cohort with a comprehensive long-term follow-up. The present study, designed as a prospective nonrandomized clinical trial, involved each patient undergoing a 4D-flow cardiac magnetic resonance scan post-surgery. This scan meticulously examined patient-specific computational fluid dynamics models to evaluate WSS at the ascending aortic wall. Four-dimensional cardiovascular magnetic resonance flow imaging proved instrumental in enabling a comprehensive and accurate assessment of flow in a single acquisition [5].