Monitoring in vivo absorption of a drug-eluting bioabsorbable stent with intravascular ultrasound-derived parameters a feasibility study.
OBJECTIVE
The aim of this study was to investigate the feasibility of using quantitative differential echogenicity to monitor the in vivo absorption process of a drug-eluting poly-l-lactic-acid (PLLA) bioabsorbable stent (BVS, Abbott Vascular, Santa Clara, California).


BACKGROUND
A new bioabsorbable, balloon-expanded coronary stent was recently evaluated in a first-in-man study. Little is known about the absorption process in vivo in diseased human coronary arteries.


METHODS
In the ABSORB (Clinical Evaluation of the BVS everolimus eluting stent system) study, 30 patients underwent treatment with the BVS coronary stent system and were examined with intracoronary ultrasound (ICUS) after implantation, at 6 months and at 2-year follow-up. Quantitative ICUS was used to measure dimensional changes, and automated ICUS-based tissue composition software (differential echogenicity) was used to quantify plaque compositional changes over time in the treated regions.


RESULTS
The BVS struts appeared as bright hyperechogenic structures and showed a continuous decrease of their echogenicity over time, most likely due to the polymer degradation process. In 12 patients in whom pre-implantation ICUS was available, at 2 years the percentage-hyperechogenic tissue was close to pre-implantation values, indicating that the absorption process was either completed or the remaining material was no longer differentially echogenic from surrounding tissues.


CONCLUSIONS
Quantitative differential echogenicity is a useful plaque compositional measurement tool. Furthermore, it seems to be valuable for monitoring the absorption process of bioabsorbable coronary stents made of semi-crystalline polymers.
Bruining
Nico
N
Thoraxcenter, Department of Cardiology, Erasmus Medical Center, Rotterdam, the Netherlands. n.Bruining@erasmusmc.nl
de Winter
Sebastiaan
S
Roelandt
Jos R T C
JR
Regar
Evelyn
E
Heller
Iddo
I
van Domburg
Ron T
RT
Hamers
Ronald
R
Onuma
Yoshinobu
Y
Dudek
Darius
D
Webster
Mark W I
MW
Thuesen
Leif
L
Ormiston
John A
JA
Cheong
Wai-Fung
WF
Miquel-Hebert
Karine
K
Veldhof
Susan
S
Serruys
Patrick W
PW
D020341:Absorbable Implants; D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D054855:Drug-Eluting Stents; D005060:Europe; D000068338:Everolimus; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019344:Lactic Acid / Q000737:chemistry*; D009520:New Zealand; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D012995:Solubility; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
D002317:Cardiovascular Agents; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D000068338:Everolimus; D020123:Sirolimus