Relationship of vascular remodeling and restenosis after interventional therapy: an experimental study on rabbit atherosclerotic iliac artery model.
OBJECTIVE
To evaluate the relative contribution of every part of vascular wall to lumen area loss after angioplasty.


METHODS
Angioplasty was performed on rabbits iliac atherosclerosis model. Histomorphometric results of histological cross-sectional areas from target vessels of animals killed immediately after angioplasty (acute group, n = 20) were compared with those of the same areas from animals killed 4 weeks after the procedure (chronic group, n = 23), when restenosis occurred in this model. If taking 30% diameter decrease as restenosis criteria, the chronic group was further divided into two subgroups (nonrestenosis subgroup [NRS, n = 9] and restenosis subgroup [RS, n = 14]) and their histomorphometric results were also compared.


RESULTS
The lumen area decreased by 0.48 mm2 from acute group to chronic group (acute group 0.86 +/- 0.23 mm2 vs chronic group 0.38 +/- 0.20 mm2, P < 0.001). Over the same period intimal area increased by 0.12 mm2 and the area circumscribed by inner elastic lamina (IEL area) decreased by 0.36 mm2. Intimal hyperplasia could only explain 25% of the later lumen area loss. We further found a more significant IEL area decrease in RS subgroup than in NRS subgroup (0.68 +/- 0.35 mm2 vs 0.94 +/- 0.14 mm2, P < 0.05), despite the same intimal area (0.39 +/- 0.16 mm2 vs 0.41 +/- 0.31 mm2, P = NS). The different lumen area between RS subgroup and NRS subgroup (0.27 +/- 0.10 mm2 vs 0.55 +/- 0.10 mm2, P < 0.001) was predominantly due to the greater IEL shrinking in RS subgroup.


CONCLUSIONS
Our data indicate that later lumen area loss after angioplasty results from both intimal hyperplasia and arterial shrinking (remodeling), but the latter plays a much greater role.
Jia
X
X
Department of Cardiology, Affiliated Hospital of Hebei Medical College for Continuing Education, Redstar Road, Baoding City, Hebei 071000, China.
Huo
Y
Y
Zhu
G
G
D015906:Angioplasty, Balloon, Coronary; D000818:Animals; D001161:Arteriosclerosis / Q000473:pathology / Q000628:therapy*; D003251:Constriction, Pathologic; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D007083:Iliac Artery / Q000473:pathology; D008297:Male; D011817:Rabbits