Page 58 - JCTR-11-4

Journal of Clinical and
Translational Research AR-TAVR coaxiality assessment using 3DP

transapical TAVR. In the future, randomized clinical trials will be needed to evaluate
the efficacy and accuracy of pre-procedural 3DP simulations and the coaxiality index
in treating patients with pure AR undergoing transapical TAVR.

Keywords: Aortic regurgitation; Transcatheter aortic valve replacement; Three-dimensional
printing; Coaxiality; Clinical outcome

1. Introduction 2. Materials and methods

Aortic regurgitation (AR) is the fourth most common 2.1. Study design and population
type of valvular heart disease globally, with a prevalence A total of 694 high-risk patients with AR from six high-volume
1
of 4.9%. The indications for transcatheter aortic valve centers (Xijing Hospital; Beijing Fuwai Hospital; West China
2
replacement (TAVR) continue to expand, and its safety Hospital Affiliated with Sichuan University; Zhongshan
and efficacy have been demonstrated even in patients with Hospital Affiliated with Fudan University; Anzhen Hospital
3,4
low-surgical risk aortic stenosis (AS). However, TAVR Affiliated to Capital Medical University; and Guangdong
presents unique anatomical challenges in patients with AR, Provincial People’s Hospital) were enrolled from January
including a larger annulus, lack of calcification, and dilation 2018 to March 2020. The inclusion criteria included (i)
of the ascending aorta. As a result, off-label implantation age ≥60 years; (ii) New York Heart Association functional
5
using a conventional transcatheter heart valve (THV) is class ≥II; (iii) ≥Moderate AR diagnosed by transthoracic
more difficult, leading to a higher incidence of paravalvular echocardiography; and (iv) European System for Cardiac
leakage (PVL), THV displacement, and conduction block. 6 Operative Risk Evaluation score II >12% or Society of
In its early stages, the J-Valve (Jiecheng Medical Co., Thoracic Surgeons (STS) score >8%. The exclusion criteria
LTD., China) was developed specifically for the treatment were (i) <Moderate AR; (ii) myocardial infarction within the
of pure AR and has demonstrated therapeutic effectiveness past month; (iii) history of endocarditis; (iv) hypertrophic
in China. The distinctive design features of the THV cardiomyopathy; and (v) transient ischemic attack/stroke
7
include three U-shaped positioning keys and a movable within the past 6 months. In addition, patients unsuitable
connection between the keys and the THV. The inward for transapical TAVR were excluded from the study. Of
7
force of the positioning keys and the outward radial force the patients enrolled initially, 82 were excluded. The 3DP
of the THV clamp the native leaflets between them like a simulation was performed alternately in each subset of five
paper clip. To ensure maximum fixation of the THV, it is consecutive patients (two cases assigned to the 3DP group
critical to place the U-shaped keys accurately and expand and three cases to the non-3DP group) per center. Thus, the
them fully to achieve THV coaxiality, thereby reducing the remaining 612 patients were assigned to the non-3DP group
incidence of PVL and other procedural complications. 7,8 (n = 384) or the 3DP group (n = 228) (Figure 1). This study
conformed to the Declaration of Helsinki and was approved
Conventionally, computed tomography angiography by the Ethics Committee of Xijing Hospital (approval
(CTA) has provided essential information for sizing THVs number: KY-20192138-C-1). All patients provided written
in patients with AR, as it does for those with AS. However, informed consent for TAVR and follow-up data collection.
the size and orientation of the cusps vary among individuals,
impacting how well the U-shaped keys fit into the cusps. In 2.2. Pre-operative imaging assessment
addition, CTA may be limited in accurately displaying THV All patients were required to complete an electrocardiograph-
orientation after implantation. To address this, we used gated coronary CTA before undergoing the procedure.
9,10
three-dimensional printing (3DP) to simulate the insertion The standard Digital Imaging and Communications in
of U-shaped keys into the sinuses and to optimize cusp Medicine format for CTA data was imported into 3Mensio
fitting, thereby maximizing clamping force.
software (Materialise, Belgium) to assess the aortic root,
At present, no clinical studies have assessed the impact including the annulus and the left ventricular outflow
of coaxiality in transapical TAVR for patients with pure tract, with particular attention to the size, location, and
AR. Therefore, the goal of this study was to evaluate the position of the sinuses of Valsalva and the angle of the
feasibility of using 3DP to adjust the coaxiality of the aorta. Horizocardia is defined as an angle >48° between the
J-Valve before TAVR, to improve implantation accuracy long diameter of the heart and the longitudinal diameter
and clinical efficacy. of the chest. Transthoracic echocardiography mainly
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Volume 11 Issue 4 (2025) 52 doi: 10.36922/jctr.24.00084