In Vitro Testing of a Temporary Catheter-Based Aortic “Parachute” Valve

Abstract

Recently developed technologies allow aortic valve implantation off-pump in a beating heart. In this procedure, the native, stenotic aortic valve is not removed, but simply crushed by a pressure balloon mounted on a percutaneous catheter. Removal of the native aortic cusps before valve replacement may reduce the incidence of annular or cuspal calcium embolization and late perivalvular leaks and increase implantable valve size. However, a temporary valve system in the ascending aorta may be necessary to maintain hemodynamic stability by reducing acute aortic regurgitation and left ventricular volume overload. This study evaluates the hemodynamic effects of a wire-mounted, monoleaflet, temporary valve apparatus in a mechanical cardiovascular simulator. Aortic flow, systemic pressure and left ventricular pressure were continuously monitored. An intraluminal camera obtained real-time proximal and distal images of the valve in operation. Insertion of the parachute valve in the simulator increased diastolic pressure from 7 to 38 mm Hg. Cardiac output increased from 2.08 to 4.66 L/min and regurgitant volume decreased from 65 to 23 mL. In conclusion, placement of a temporary valve in the ascending aorta may help maintain hemodynamic stability and improve off-pump aortic valve replacement.

Qualitative haemodynamic validation of a percutaneous temporary aortic valve: a proof of concept study

“…Also similar to our findings, there were no changes in cardiac output or peak systolic pressure with the use of the temporary valve. Similar findings were observed in another temporary valve design with the appearance of a 'parachute' [8,9]. The wire-mounted, monoleaflet temporary valve apparatus was tested in vitro in a mechanical cardiovascular simulator as well as in vivo in a pig model.…”

“…In a beating heart without the protection of cardiopulmonary bypass support, explantation of the native aortic valve would cause massive aortic regurgitation leading to unsustainable global ischaemia and heart failure. Hence, the advent of the temporary aortic valve support concept is relevant to the continued development of the percutaneous or minimally-invasive transcatheter replacement procedure [7][8][9][10][11].…”

Transapical off-pump removal of the native aortic valve: A proof-of-concept animal study

“…We previously tested this valve in a mechanical cardiovascular simulator and found that the valve increased output and decreased regurgitation. 21 After placement of the temporary valve in the supracoronary position, diastolic AP increased (P < .001) and a tendency toward T-wave normalization was noted (Figure 5). Unexpectedly, absolute CF decreased further compared with the no-cusp situation, although the difference was not statistically different (Table 1).…”

Percutaneous aortic valve replacement (part 3): Balloon counterpulsation of a novel temporary aortic valve

“…The choice of using inflatable balloons in the TAV is for its ease of deployment and removal. Another method to create a temporary valve has been explored (12).…”