Temporal, biomechanical evaluation of a novel, transcatheter polymeric aortic valve in ovine aortic banding model

Abstract

ObjectivesThe aim of the study is to evaluate the functionality, durability, and temporal biocompatibility of a novel, balloon-expandable polymeric transcatheter heart valve (ATHV) system (InFlow, CardValve Consortium, Poland). Along with expanding TAVI indications, the demand for new transcatheter valves is increasing.MethodsA surgical ascending aortic banding model was created in 20 sheep. Two weeks later, 16 sheep were implanted with ATHV systems (15–16F). Three animals were euthanized after a 30-day follow-up, four animals after a 90-day follow-up, and six animals after a 180-day follow-up. A follow-up transthoracic echocardiography (TTE) was performed.ResultsThere was one procedure-related (6,25%) and two model-related deaths (12,5%; banding site calcification with subsequent infection originating externally from banding). TTE revealed the flow gradients (max/average) of 30,75/17,91; 32,57/19,21; and 21,34/10,63 mmHg at 30, 90, and 180 days, respectively. There were two cases of low-degree regurgitation after 180 days with no perivalvular leak observed. Histopathological analysis showed no valve degeneration at terminal follow-up with optimal healing. Small thrombi were present at the aortic wall adjacent to the base of the leaflets, and between the aortic wall and the stent in most of the valves; however, leaflets remained free from thrombi in all cases. Scanty calcifications of leaflets were reported in three animals evaluated 180 days after implantation.ConclusionThis preclinical study in the aortic banding model showed good hemodynamic performance, durability, and biocompatibility of the novel ATHV. Furthermore, regulatory studies with longer follow-ups are warranted.

Polymeric prosthetic heart valves: A review of current technologies and future directions

“…However, at 90 days in three animals a thin thrombus was visible on the ventricular surface, presenting as surface deposits, well delineated and firmly attached to the base of the leaflets and adjacent stent elements contacting the aortic wall. Overall, the changes reported did not influence the valve hemodynamics as reported by the authors ( 32 ).…”

“…Waveform, frequency, and stroke conditions were all adjusted in the same manner as all tested prototypes. All valves passed 40 million cycles and further tests are ongoing ( 32 ).…”

“…The polymeric valve was tested in a chronic large animal model ( 32 ). Sixteen sheep underwent the TAVR procedure.…”

“…As described in previous sections, the Inflow TAVR valve was implanted in 16 sheep that were followed for 30 ( n = 3), 90 ( n = 4), or 180 ( n = 6) days ( 32 ). Histopathologic examination as well as X-ray analysis showed no calcifications of leaflets, free margins, and commissures in all cases at 30 days.…”