Head-to-Head Comparison of a Drug-Free Early Programmed Dismantling Polylactic Acid Bioresorbable Scaffold and a Metallic Stent in the Porcine Coronary Artery

Abstract

Background-We aimed to evaluate a new drug-free fully bioresorbable lactic acid-based scaffold designed to allow early dismantling synchronized with artery wall healing in comparison with a bare metal stent (BMS). Methods and Results-Twenty-three BMS (3.0×12 mm) and 36 lactic acid-based bioresorbable scaffolds (BRS, 3.0×11 mm) were implanted in porcine coronary arteries. QCA and optical coherence tomographic analyses were performed immediately after implantation and repeated after 1, 3, and 6 months. Microcomputed tomography was used to detect scaffold dismantling. Polymer degradation was evaluated throughout the study. The primary end-point was late lumen loss, and the secondary end-points were scaffold/stent diameter and acute recoil. Acute recoil was low and comparable between the BRS and the BMS groups (4.6±6.7 versus 4.6±5.1%; P=0.98). BRS outer diameter increased significantly from 1 to 6 months indicating late positive scaffold remodeling (P<0.0001), whereas BMS diameter remained constant (P=0.159). Late lumen loss decreased significantly from 1 to 6 months in the BRS group (P=0.003) without significant difference between BRS and BMS groups at 6 months (P=0.68). Microcomputed tomography identified BRS dismantling starting at 3 months, and weight-average molar masses of scaffold parts were 20% and 14% of their initial values at 3 and 6 months. Conclusions-BRS and BMS have similar 6-month outcomes in porcine coronary arteries. Interestingly, BRS dismantling was detected from 3 months and resulted in late lumen enlargement by increased scaffold diameter at 6 months. (Circ Cardiovasc Interv. 2014;7:70-79.)

Comparison of a Drug‐Free Early Programmed Dismantling PDLLA Bioresorbable Scaffold and a Metallic Stent in a Porcine Coronary Artery Model at 3‐Year Follow‐Up

“…We have previously reported that dismantling of the ART‐BRS occurs as early as 3 months after scaffold implantation according to micro–computed tomography 9. Early dismantling is the dominant feature of the ART‐BRS and was confirmed by OCT imaging and histopathologic assessment.…”

“…QCA was carried out and analyzed by an independent core laboratory (AccelLAB, Montreal, QC, Canada) as previously described 9. The Medis QCA‐CMS 6.0 system (Raleigh, NC) was used for QCA measurement.…”

“…The dismantling of ART‐BRS began at 3 months after implantation, which allowed for rapid vascular restoration with progressive lumen enlargement up to 6 months 2, 8, 9. The aim of the current study was to characterize the vascular response following implantation of a novel ART‐BRS in comparison to bare metal stents (BMS) by angiography, histopathology, and biochemical analysis of molecular weight up to 36 months in a healthy porcine coronary artery model.…”

Comparative Characterization of Biomechanical Behavior and Healing Profile of a Novel Ultra-High-Molecular-Weight Amorphous Poly- l -Lactic Acid Sirolimus-Eluting Bioresorbable Coronary Scaffold

“…16 Experimental data using a poly-dl-lactic acid drug-free BRS in a porcine model showed that a BRS displaying a rapid degradation profile (molecular weight loss ≈86% at 6 months) presented similar healing profiles compared with bare metal stent at 6 months. 17 However, clinical data suggest that rapid polymer absorption reduces radial force of the scaffold prematurely, which can lead to late recoil and adverse clinical events 18 ; moreover, in the clinical setting, a longer resorption period (6-9 months) may provide a more stable device dismantling process and better clinical outcomes. The BRS tested in the present study is made of PLLA struts of 150 µm thickness that are arranged in a zigzag helical design and had a peak circumferential radial force of ≈0.11 MPa, similar to metallic stents right after deployment.…”

Comparison of early vascular morphological changes between bioresorbable poly-L-lactic acid scaffolds and metallic stents in porcine iliac arteries

“…1 This polymer has been shown to be biocompatible and well tolerated according to the results of both in vitro and in vivo studies. [5][6][7] The Igaki-Tamai stent (ITS, Kyoto Medical Planning Co., Ltd., Kyoto, Japan), which is made of PLLA, was the first BRS developed for use in humans in 2000, and it has shown promising results in coronary arteries and superficial femoral arteries (SFAs) in clinical trials. 6,8,9 This scaffold has been commercially available for treating peripheral artery disease in 15 countries of Europe since 2009.…”