Material and methods
Study subjects : all patients diagnosed with isolated aortic valve disease, had indications for surgery according to AHA guidelines, underwent aortic valve reconstruction surgery using autologous pericardium by Ozaki’s procedure at Cardiovascular Center, E Hospital from June 2017 to December 2019.
Study design : an observational study of all patients with isolated aortic valve disease undergoing aortic valve reconstruction surgery by Ozaki’s technique.
Surgical procedures : All surgical procedures were performed by surgeons who received direct hands-on training and training certificate from Prof. Ozaki. This surgery was performed via a sternotomy, therein the pericardium was elaborately dissected and harvested in a minimum size of 8x8 cm by ultrasonic scalpel. Then, the pericardium was treated with glutaraldehyde 0,6% solution in 10 minutes before being rinsed with normal saline for 6 minutes (repeatedly three times). The establishment of the cardiopulmonary bypass system utilized 03 cannulas inserted respectively in ascending aorta, superior vena cava, and inferior vena cava. After opening the ascending aorta, diseased cusps were resected entirely. The measured distance of 2 commissures indicated the size of the reconstructed cusp using autologous pericardium. The constructed cusps were then sutured to the respective annulus. The aortic valve should be tested before closing the incision of the aorta. After aortic cross-clamp was release and the return of beating heart, transesophageal echocardiography was performed to evaluate valvular morphology and hemodynamics following termination of cardiopulmonary bypass.
Data collection and statistical analysis : preoperative variables (clinical features, subclinical parameters, echocardiography), intraoperative variables (aortic annulus size, the number of constructed cusps, aortic cross-clamp time, cardiopulmonary bypass time, …), short and mid-term outcomes (clinical features, echocardiography, complications, survival rate) were collected during a minimum of 12 months follow-up. Data were analyzed by R 4.0.0 software using t-test and ANOVA test to compare the means of different groups.
Research ethics : Our study was approved by Hanoi Medical University Institutional Ethical Review Board with approval number NCS06/HMUIRB (the most prestigious medical university of Vietnam) and the Ethics Committee of E hospital (approval number 1018/BB-BE). Patients were provided full information about different surgical methods for aortic valve disease and the advantages or disadvantages of each method before making decision.