Morphometric analysis of intimal thickening secondary to stent placement in pig carotid arteries.
OBJECTIVE
To evaluate intimal thickening secondary to stent placement or to insertion of the delivery system without stent placement in pig carotid arteries.


METHODS
Stents were placed in the right common carotid arteries of 7 pigs, and 7 other control pigs underwent only insertion of the delivery system without stent placement. Uninjured contralateral common carotid arteries of the two groups were also used as controls. Samples of arterial tissue, obtained from the area adjacent to the distal segment of the stent four weeks after placement, underwent morphometric analysis. Morphometric data were compared with findings for arterial samples from injured arteries of the control group and uninjured contralateral arteries of the two groups. The unpaired Mann-Whitney U test and the Wilcoxon t test for nonparametric samples were used for statistical analysis.


RESULTS
Greater intimal thickening was found in the group in which stents were placed (p=0.008). Changes in luminal area and media layer were not significantly different between the two groups. The comparison of contralateral carotid arteries of the two groups revealed significant changes in intimal and luminal areas. No statistically significant changes were found in medial layer area.


CONCLUSIONS
All arteries that underwent stent placement showed intimal thickening without changes in the tunica media at four weeks. Dissection and insertion of the delivery system without stent placement was associated with a lesser degree of intimal thickening.
Pasa
Márcio Bastiani
MB
Post-Graduate Program, Medicine School, Rio Grande do Sul Federal University. marciopasa@hotmail.com
Pereira
Adamastor Humberto
AH
Castro Júnior
Cyro
C
D000818:Animals; D017536:Carotid Artery, Common / Q000473:pathology*; D006965:Hyperplasia / Q000209:etiology / Q000473:pathology; D011897:Random Allocation; D015607:Stents / Q000009:adverse effects; D013552:Swine; D017539:Tunica Intima / Q000473:pathology*