ABSTRACT
Optical coherence tomography (OCT) can be used to visualize the arterial wall and atherosclerotic plaques with high resolution. In this study, we verified the application of OCT to the quantitative analysis of plaque structural dimensions and optical attenuation coefficients of the components. We assessed the effect of balloon dilation on the OCT signal from the medial layer of porcine carotid artery ex vivo. Imaging of human autopsy samples was performed from the luminal side with a high (3.5 microm axial and 7 microm lateral) resolution OCT system (approximately 800 nm) or a regular (15-20 microm axial and 20 microm lateral resolution) OCT system (approximately 1,300 nm). For each sample, dimensions were measured by histomorphometry and OCT, and the optical attenuation was measured. In a tissue culture set-up, porcine carotid arteries were dilated and the attenuation coefficients of the dilated segments were compared to a control segment for 4 h. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements for both OCT systems. For both systems, the measured attenuation coefficients for diffuse intimal thickening and lipid-rich regions differed significantly from that of calcified tissue. Balloon dilation induced a time-dependent increase in the attenuation coefficient, which may be attributed to the induction of apoptosis. In conclusion both the high and regular resolution OCT systems can image the atherosclerotic plaques precisely. Quantitative analysis of the OCT signals allowed in situ determination of the intrinsic optical attenuation coefficient for atherosclerotic tissue components within regions of interest, which can help to discriminate between plaque and arterial wall components.
Subject(s)
Carotid Arteries/pathology , Carotid Arteries/ultrastructure , Carotid Stenosis/pathology , Tomography, Optical Coherence , Analysis of Variance , Anatomy, Cross-Sectional , Animals , Biopsy, Needle , Carotid Stenosis/therapy , Catheterization , Confidence Intervals , Disease Models, Animal , Female , Humans , Immunohistochemistry , Male , Probability , Rats , Sensitivity and Specificity , Swine , Tissue Culture Techniques , Tunica Intima/pathology , Tunica Intima/ultrastructure , Tunica Media/pathology , Tunica Media/ultrastructureABSTRACT
BACKGROUND AND OBJECTIVE: Restenosis after balloon angioplasty is the summated effect of intimal hyperplasia and arterial shrinkage, both caused by hyperproliferation. In the present study, the potential of a photochemotherapeutic modality (Psoralen + UVA: PUVA) for the prevention of angioplasty induced proliferation was explored. STUDY DESIGN/MATERIALS AND METHODS: In rabbit iliac arteries, balloon dilation followed by PUVA-therapy (H = 1 J/cm2) was performed (n = 15). Contralateral arteries served as control. After 2 and 28 days of survival, the contribution of intimal hyperplasia and remodeling to lumen loss was determined by means of angiography and histological analysis. RESULTS: After 2 days, large parts of the media had become acellular, while proliferation was occurring predominantly in the adventitia in both groups. After 28 days, late loss, arterial shrinkage, but not intimal hyperplasia were larger in the PUVA group (P < 0.05). CONCLUSION: PUVA-therapy did not prevent intimal hyperplasia following balloon dilation but enhanced luminal narrowing by augmented constrictive remodeling.
