Echogenicity as a surrogate for bioresorbable everolimus-eluting scaffold degradation: analysis at 1-, 3-, 6-, 12- 18, 24-, 30-, 36- and 42-month follow-up in a porcine model

Abstract

The objective of the study is to validate intravascular quantitative echogenicity as a surrogate for molecular weight assessment of poly-l-lactide-acid (PLLA) bioresorbable scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California). We analyzed at 9 time points (from 1-to 42-month follow-up) a population of 40 pigs that received 97 Absorb scaffolds. The treated regions were analyzed by echogenicity using adventitia as reference, and were categorized as more (hyperechogenic or upperechogenic) or less bright (hypoechogenic) than the reference. The volumes of echogenicity categories were correlated with the measurements of molecular weight (Mw) by gel permeation chromatography. Scaffold struts appeared as high echogenic structures. The quantification of grey level intensity in the scaffold-vessel compartment had strong correlation with the scaffold Mw: hyperechogenicity (correlation coefficient = 0.75; P \ 0.01), upperechogenicity (correlation coefficient = 0.63; P \ 0.01) and hyper ? upperechogenicity (correlation coefficient = 0.78; P \ 0.01). In the linear regression, the R 2 for high echogenicity and Mw was 0.57 for the combination of hyper and upper echogenicity. IVUS high intensity grey level quantification is correlated to Absorb BVS residual molecular weight and can be used as a surrogate for the monitoring of the degradation of semi-crystalline polymers scaffolds.

Risk and timing of clinical events according to diabetic status of patients treated with everolimus‐eluting bioresorbable vascular scaffolds versus everolimus‐eluting stent: 2‐year results from a propensity score matched comparison of ABSORB EXTEND and SPIRIT trials

“…Conversely, Absorb had lumen decrease between post‐procedure and 6 months and lumen increase between 6‐months and 2‐years . A question to be clarified by future studies is whether Absorb may add clinical benefits after the third year of implantation, when the biodegradation process is finished and the vessel is free of its internal cage .…”

“…that consists of a polymer backbone of Poly( l ‐lactide) (PLLA) coated with a thin layer of a 1:1 mixture of Poly‐ d , l ‐lactide (PDLLA) polymer with the antiproliferative drug everolimus to form an amorphous drug‐eluting coating matrix containing 100 μg of everolimus/cm 2 of scaffold . Both PLLA and PDLLA are fully bioresorbable; PDLLA is expected to be totally resorbed by the body in nine months and PLLA in ∼36 months .…”

TCT-411 Risk and timing of clinical events according to diabetic status of patients treated with Everolimus-Eluting Bioresorbable Vascular Scaffolds vs. Everolimus-Eluting stent: 2-Year results from a propensity score matched comparison of ABSORB EXTEND and SPIRIT trials

“…Conversely, Absorb had lumen decrease between post-procedure and 6 months and lumen increase between 6-months and 2-years [4]. A question to be clarified by future studies is whether Absorb may add clinical benefits after the third year of implantation, when the biodegradation process is finished and the vessel is free of its internal cage [4,17,31].…”

“…that consists of a polymer backbone of Poly(L-lactide) (PLLA) coated with a thin layer of a 1:1 mixture of Poly-D,L-lactide (PDLLA) polymer with the antiproliferative drug everolimus to form an amorphous drug-eluting coating matrix containing 100 lg of everolimus/cm 2 of scaffold [16]. Both PLLA and PDLLA are fully bioresorbable; PDLLA is expected to be totally resorbed by the body in nine months and PLLA in 36 months [17].…”

Cardiovascular imaging 2015 in the International Journal of Cardiovascular Imaging

“…The unmatched resolution and tissue contrast of OCT makes it the natural choice. interestingly Campos et al [77] sought to validate ivuS quantitative echogenicity as a surrogate for molecular weight assessment of poly-l-lactide-acid (PllA) bioresorbable scaffold (Absorb BvS, Abbott vascular, Santa Clara, CA). The authors relied in an elaborate 9 time points porcine model.…”