Transcatheter aortic valve deployment influences neo‐sinus thrombosis risk: An in vitro flow study

Abstract

Objectives:We investigated the impact of (transcatheter heart valve) THV expansion at the level of the native annulus and implant depth on valve performance and neo-sinus flow stasis.Background: Flow stasis in the neo-sinus is one of the identified risk factors of THV thrombosis. Methods: A 29 mm CoreValve and 26 mm SAPIEN 3 were deployed under different expansions (CoreValve, SAPIEN 3) and implant depths (CoreValve) within a patientderived aortic root in a pulse duplicator. Fluorescent dye was injected during diastole into the neo-sinus and imaged over 20 cardiac cycles. Washout times were computed as a measure of flow stasis for each deployment.Results: The 10% CoreValve under-expansion improved neo-sinus washout over full expansion by 8% (p < .001), and higher CoreValve implant depth improved neo-sinus washout (p < .001). The 10% SAPIEN 3 under-expansion improved neo-sinus washout by 23% (p < .001). Under-expansion of both valve types caused higher pressure gradients and smaller effective orifice areas than full expansion.Conclusions: Neo-sinus flow stasis is influenced by THV expansion and implant depth (CoreValve). The 10% valve under-deployment (oversizing) may facilitate reduced flow stasis in the neo-sinus with minimal increase in pressure gradients. This strategy may be helpful for patient anatomies, which are in-between transcatheter valve sizes. K E Y W O R D S aortic valve disease, aortic valve disease, percutaneous intervention, transcatheter valve implantation

Hemodynamics inside the neo‐ and native sinus after TAVR: Effects of implant depth and cardiac output on flow field and coronary flow

“…The neo-sinus washout was generally better for WP70, and was reduced for both lower implant depths. These findings agree with other recent studies 14,28 stating that a lower implant depth increases the area/volume of neo-sinus and therefore increases the risk of flow stasis. Later washout in low implant depth was found, 28 which increases thrombus severity.…”

“…These findings agree with other recent studies 14,28 stating that a lower implant depth increases the area/volume of neo-sinus and therefore increases the risk of flow stasis. Later washout in low implant depth was found, 28 which increases thrombus severity. This means reversely the neo-sinus thrombus incidence is reduced for higher THV placement, in agreement with Midha et al 15 Prevention of neo-sinus flow stasis is an important issue, because the neo-sinus is the region where thrombus development was observed to originate.…”

“…In this work, we have investigated in detail the effect of three THV implant depths with a focus on the flow within the neo-and native sinus and on the left coronary flow. Different from previous studies, 14,28 the prosthesis was implanted into a compliant (not rigid) silicone aorta including native silicone leaflets and a correct anatomic shape of the sinuses of Valsalva and coronary ostia. Furthermore, left and right coronary flows were included, but not externally imposed as found in Madukauwa-David et al 14 and the center plane through the left coronary cusp and left coronary artery was investigated.…”

“…Several previous in vitro studies were conducted to better understand the hemodynamics inside the native and/or neo sinus 11,12,21‐27 . However, these studies have several limitations including the use of a rigid aorta, 14,28 the absence of native leaflets and coronary flow 11,12,21,23,25,26,28 …”

“…19,20 Several previous in vitro studies were conducted to better understand the hemodynamics inside the native and/or neo sinus. 11,12,[21][22][23][24][25][26][27] However, these studies have several limitations including the use of a rigid aorta, 14,28 the absence of native leaflets and coronary flow. 11,12,21,23,25,26,28 This study aims to investigate in vitro the effect of three different implant depths of a commercially available supra-annular THV, implanted into a flexible, anatomically correct silicone aorta including native leaflets, on the hemodynamics inside the neo-and native sinus.…”