“Close but no cigar”: Successful aortic valve repair using autologous pericardium

The history of aortic valve repair with pericardium starts with Yacoub and Batista who used a single patch of bovine pericardium to construct an entire trileaflet aortic valve in patients with both aortic stenosis as well as regurgitation. As little as possible of the free edge of the leaflet was resected and a large strip of glutaraldehyde‐fixed bovine pericardium was sutured to the cut free edge of the leaflets. This created very tall leaflets and very high commissures to increase the coaptation of the valve leaflets. However, the excessive leaflets had a tendency to bend toward the sinuses of Valsalva, occasionally causing serious coronary ischemia by obstructing coronary ostia. To keep the leaflets away from the sinuses and avoid the coronary ischemia, Duran used a plastic container with three consecutive bulges to mold the shape of the leaflets during fixation. Pericardium was draped over these bulges during glutaraldehyde fixation to give the neoleaflets a curved shape facing away from the sinuses. Using this technique, the group reported a survival of 85% with a mean follow‐up of 10.5 years, in a population of patients with a mean age of 31 years. Freedom from structural valve degeneration was 78% and 55% at 10 and 16 years, respectively. Interestingly, while initially reported as aortic valve replacement, it was later labeled as aortic valve reconstruction by the group. Bicuspid aortic valve was a contraindication. Dr Ozaki's technique of “aortic valve reconstruction” is based on recreating the three leaflets and commissures, rather than extending the leaflet and commissural heights to increase coaptation. The leaflets are completely excised and replaced with three separate pieces of autologous glutaraldehyde‐fixed pericardium. New leaflets are sutured directly to the annulus. Even bicuspid valves are repaired in a trileaflet fashion by creating a new commissure. While he has demonstrated excellent midterm results, the mean age of the patients was 71 years. Even though this procedure can be done minimally invasively, this is the age group in which transcatheter aortic valve implantation has become the procedure of choice in the western world. Ozaki procedure is therefore unlikely to see widespread use in this older patient population. However, in the developing world, where millions of patients still suffer from rheumatic valvular disease and up to 12–13 million patients suffer from rheumatic aortic valve disease, this procedure has tremendous potential. There have been reports of its successful use in Brazil, Russia, and Vietnam, for instance, where the population has been relatively younger. In this issue of Journal of Cardiac Surgery, Ngo et al. from Vietnam, presents their experience with Ozaki procedure in 72 patients with a mean age of 53 years and mean follow‐up of 26 months. Two patients required conversion to prosthetic valve replacement due to coronary obstruction with reconstructed leaflets. There was one 30‐day mortality due to cardiac tamponade from bleeding and another two died due to pseudoaneurysm rupture resulting from mediastinitis. In the follow‐up period, two patients required reoperation for infected endocarditis. Only one patient had moderate regurgitation immediately following surgery and should be considered a failure of the operation. None of the other complications can be attributed to the procedure itself. These results are comparable to those of others. When Dr Ozaki presented his initial series of patients, the concern was reproducibility. However, with the creation of “AVNeo” system, which uses standardized sizing templates for the autologous pericardium based on intercommissural distance and coaptation heights, this procedure has become quite reproducible. This study by Nguyen et al., is a testament to the reliability and reproducibility of the Ozaki procedure or neo‐cuspidization as it is also called. Another potential use of this procedure is in the pediatric population. Since its approval by Food and Drug Administration in 2014, it has also been used in pediatric patients. By not restricting the aortic root, this procedure allows the aortic root to grow with age. Since 2015, pediatric sizers 13 and 15mm have also been available in addition to the adult sizes 17–31mm.