Modification of Calcified Native and Surgical Bioprosthetic Aortic Valves: Lessons From the Bench.

BACKGROUND

Leaflet modification (LM) techniques, including electrosurgical and mechanical BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction) and intraleaflet deployment, are important in the lifetime management of aortic valve disease. However, benchtop assessment is limited.

OBJECTIVES

The aim of this study was to provide a benchtop assessment of LM in native valves and bioprosthetic surgical aortic valves (SAVs).

METHODS

Features of calcific native aortic valves (n = 100) and naive SAVs (7 types) were assessed. Calcific native cusps (n = 13) and SAV leaflets (n = 14) stratified by calcific load were modified by electrosurgical or mechanical BASILICA or intraleaflet deployment with assessment of splay, laceration patterns, and embolic debris. The impact of leaflet length and valve-in-valve implantation on splay area was analyzed.

RESULTS

In native cusps, calcification in traversal and laceration zones was common (89% and 97%, respectively). LM was feasible across calcification severities, although increasing calcification was associated with laceration difficulty (P = 0.028), leaflet tears (P = 0.02), and increased embolic debris (P < 0.05). Leaflet splay decreased with shortening of leaflet length (68.9% ± 10.7% at 5 mm; R2 = 0.72) and increased with simulated valve expansion in a limited analysis. In SAVs, neoskirt heights and features varied. LM was feasible across SAV leaflet calcification levels. No overall association between calcification and debris was observed; however, in a restricted subset, higher calcification was associated with increased debris (P = 0.035). SAV leaflet splay decreased with leaflet length (80.2% ± 8.8% at 5 mm; R2 = 0.84) and generally increased with simulated valve expansion, but this varied by SAV type.

CONCLUSIONS

Features of native aortic valves and SAVs impact the efficacy of LM. LM is feasible across a spectrum of calcific disease. Further study is required.