Attenuation of the media of coronary arteries in advanced atherosclerosis

Isner, Jeffrey M.; Donaldson, Roberta Fortin; Fortin, Auguste H.; Tischler, Arthur S.; Clarke, Richard H.

doi:10.1016/s0002-9149(86)80015-7

Cited by 117 publications

(35 citation statements)

References 13 publications

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“…These hypotheses need to be confirmed with clinical trials. Third, arteries with significant atherosclerotic plaque burden have destruction or thinning of the media underlying the plaque [14,15]. It is unknown whether OCR may distinguish a plaque/adventitia border in a similar manner as the plaque/media boundary.…”

Section: Discussionmentioning

confidence: 99%

Optical coherent reflectometry: A new technique to guide invasive procedures

Yamashita

Kasaoka

Son

et al. 2001

Cathet Cardio Intervent

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The success rate of percutaneous transluminal coronary angioplasty for chronic total arterial occlusions is still unsatisfactory. Inability to cross the lesion with a guidewire is a major cause of failure. Optical coherent reflectometry (OCR) is a new method of using laser light to measure the depth of tissue from the end of an optic fiber. This study tests whether an OCR prototype guidewire provides a guidance system that might be useful to assist reopening chronic total arterial occlusions. An OCR fiber optic within a 0.014″ hypotube was developed using the interference pattern of two reflected light beams (wave length 1,300 nm). To determine if OCR can distinguish different tissue types, plaques of human lower extremity arterial segments were visually divided into three types (calcified, white, or yellow). The slope of the initial reflectance of the OCR curve was calculated and compared between the three groups. In six other arteries, the OCR wire was advanced longitudinally through occluded human artery segments in vitro. Guidewire position was determined by OCR and compared to the position of the guidewire tip observed simultaneously by intravascular ultrasound (IVUS) imaging. In 16 arterial surface segments, calcified plaques had a significantly steeper slope than white or yellow plaques (−227.2 ± 82.2; −81.5 ± 12.9; −103.6 ± 19.6 dB/mm; P < 0.01). For the determination of the guidewire position, IVUS and OCR corresponded correctly in 82% of 28 measurements. Sensitivity and specificity of OCR for detection of plaque versus the media/adventitia boundary were 79% and 89%, respectively (P < 0.001). OCR can distinguish calcified from noncalcified plaque and may distinguish plaque from the media/adventitia boundary. This technology may be useful as a means to help navigate a guidewire safely through an occluded artery. Cathet Cardiovasc Intervent 2001;54:257–263. © 2001 Wiley‐Liss, Inc.

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Section: Discussionmentioning

confidence: 99%

Optical coherent reflectometry: A new technique to guide invasive procedures

Yamashita

Kasaoka

Son

et al. 2001

Cathet Cardio Intervent

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“…First, the composition of the stenotic plaques may be quite different, containing varying amounts of fibrous tissue, lipid, calcium, and organized thrombus.52 Second, the shape of the lesion is noted to be concentric in 30% of all stenotic lesions, eccentric and polymorphous in 40%, and eccentric or "slit-like" in 30%.52 Third, as the atheroma increases in the vessel wall, the amount of medial smooth muscle decreases and may eventually be replaced almost entirely by plaque tissue. 53 The disease-free wall segment of the coronary stenotic lesions has been noted to vary from 1% to 38% of total wall circumference in autopsy studies. 54 One may therefore postulate that every coronary stenotic lesion has at least two relevant characteristics: 1) different composition of plaque structure and smooth muscle around the entire circumference of the arterial wall, and 2) distinct morphologic plaque characteristics and thus a unique physical property that determines how it will respond to balloon dilatation.…”

Section: Anatomic Substrate For Restenosismentioning

confidence: 99%

Restenosis after coronary angioplasty. Potential biologic determinants and role of intimal hyperplasia.

1989

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Restenosis after successful PTCA remains a major problem limiting the efficacy of the procedure. The pathophysiologic mechanism of restenosis has been enigmatic so far, but accumulated evidence strongly suggests that intimal hyperplasia is the major mechanism. Based on current understanding of the process of intimal hyperplasia, one unifying concept may be that there are at least two major local biologic determinants influencing this process, lesion characteristics and regional flow dynamics. Lesion characteristics include the plaque structure and the quantity of smooth muscle. These may provide the anatomic substrate that determines the extent of injury and the degree of smooth muscle cell proliferation. The amount of smooth muscle cells in the stenotic lesion activated by injury to undergo proliferation may determine the eventual bulk of the restenotic lesion. In addition, low wall shear stress could promote intimal hyperplasia and cause structural change of vessels to decrease the lumen, whereas high wall shear stress exerts the opposite effects. Intimal hyperplasia after balloon injury is a complex process involving platelets, growth factors, endothelial cells, smooth muscle cells, mechanical injury, wall shear stress, and probably other unknown factors. Platelets not only contribute growth factors such as PDGF but also cause organized thrombus. Different growth factors may be involved in initiating smooth muscle cell proliferation and may come from many different sources, including smooth muscle cells, endothelial cells, and macrophages. Intact confluent endothelial cells may produce heparin sulfates and inhibit intimal proliferation; however, regenerating endothelial cells may have the opposite effect. Thus, the proliferative potential of smooth muscle cells, endothelial recovery, extent of injury, wall shear stress, and other unknown factors may all influence this process. Based on these concepts concerning the biology of restenosis, some research directions concerning potential forms of therapy are proposed.

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“…Similar thinning of the media in heavily diseased coronary arteries of humans has been reported. 34 In cholesterol-fed rabbits that received balloon expandable intravascular stents in diseased aortas that were observed for as long as 6 months, there was no restenosis in the stented section of the aorta, and optical analysis showed the plaque to be confined between the neointima and the atrophic media ( Figures 4A and 4B). 18 In a recent study, Thubrikar and colleagues35 looked at a similar model in a different way.…”

mentioning

confidence: 95%