Aortic valve neocuspidization: A bright future in pediatric aortic valve surgery?

A biomimetic multilayered polymeric material designed for heart valve repair and replacement

Materials currently used to repair or replace a heart valve are not durable. Their limited durability related to structural degeneration or thrombus formation is attributed to their inadequate mechanical properties and biocompatibility profiles. Our hypothesis is that a biostable material that mimics the structure, mechanical and biological properties of native tissue will improve the durability of these leaflets substitutes and in fine improve the patient outcome. Here, we report the development, optimization, and testing of a biomimetic, multilayered material (BMM), designed to replicate the native valve leaflets. Polycarbonate urethane and polycaprolactone have been processed as film, foam, and aligned fibers to replicate the leaflet's architecture and anisotropy, through solution casting, lyophilization, and electrospinning. Compared to the commercialized materials, our BMMs exhibited an anisotropic behavior and a closer mechanical performance to the aortic leaflets. The material exhibited superior biostability in an accelerated oxidization environment. It also displayed better resistance to protein adsorption and calcification in vitro and in vivo. These results will pave the way for a new class of advanced synthetic material with long-term durability for surgical valve repair or replacement.

Modified Ozaki Procedure Including Annular Enlargement for Small Aortic Annuli in Young Patients

BACKGROUND

Aortic valve neocuspidization (AVNeo) (Ozaki procedure) has excellent midterm results in adults. Outcomes in patients with a small native aortic annulus are unknown. We report early outcomes in young patients with small native aortic valve annuli.

METHODS

Retrospective data of patients undergoing AVNeo between 2015 and 2019 were reviewed. Patients with native aortic annulus less than 21 mm undergoing 3-leaflet AVNeo were included.

RESULTS

A total of 51 patients were identified (median age 7.9 years; median weight 21 kg), and 80% patients were less than or equal to 12 years age. Preoperative indication was aortic regurgitation (AR) (n = 23), aortic stenosis (AS) (n = 22), or mixed AS and AR (n = 6). Baseline anatomy was quadricuspid (n = 1), tricuspid (n = 23), bicuspid (n = 15), or unicuspid (n = 12) valve. Preoperative peak gradient for AS and mixed AS and AR patients was 55.36 mm Hg. Median native annulus diameter was 17 mm; sinus and annular enlargements were required in 22 patients and 9 patients, respectively. Median intensive care unit and hospital length of stay were 2.0 days and 7.2 days, respectively. There were no reinterventions, and there was 1 hospital mortality unrelated to aortic valve. At discharge, 94% of patients had less than or equal to mild AR, and the median peak gradient was 18 mm Hg. At mean follow-up of 11.9 months, 80% and 82% of patients had less than moderate AR and AS, respectively. Three patients required surgical reintervention. In annular enlargement patients, mean annulus Z score remained greater than 0 at follow-up.

CONCLUSIONS

The Ozaki procedure has acceptable short-term results in young patients with small aortic annuli. A larger aortic annulus can be achieved with surgical annular enlargement. Long-term follow-up is necessary to determine late valve function and potential continued annular growth.

Aortic valve neo-cuspidation using the Ozaki technique for acquired and congenital disease: where does this procedure currently stand?

The surgical treatment options for pediatric aortic valve disease are limited. The Ozaki procedure, which involves templated creation of new aortic valve leaflets, has proved to be a promising surgical technique. This review aims at elaborating the indications, technical intricacies, and outcomes of the aortic valve neo-cuspidization procedure (Ozaki procedure) in the pediatric population.