Copyright © 2007, European Society of Cardiology
The dynamic vasa vasorum
aDepartment of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
bDepartment of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
* Corresponding author. Department Physiology and Biomedical Engineering, Alfred 2-409, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905. Tel.: +1 507 255 1939; fax: +1 507 255 1935. elran{at}mayo.edu
Received 3 January 2007; revised 18 June 2007; accepted 21 June 2007
| Abstract |
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The function of vasa vasorum is both to deliver nutrients and oxygen to arterial and venous walls and to remove "waste" products, either produced by cells in the wall or introduced by diffusional transport through the endothelium of the artery or vein. Although the relationship between changes in vasa vasorum characteristics and the development of atheromatous plaques is well documented, the role of vasa vasorum, especially in terms of their appearance and disappearance in disease processes such as atherosclerosis, are still not clearly understood in terms of their being causative or merely reactive. However, even if their proliferation is merely reactive, these new microvessels may be a source of disease progression by virtue of endothelial impairment and as a pathway for monocytic cells to migrate to sites of early disease. As both these features are aspects of the vasa vasorum function, this Review focuses on the following issues: 1) acute modulation of vasa vasorum patency due to surrounding compressive forces within vessel wall and due to variable tone in the smooth muscle within proximal vasa vasorum and 2) chronic angiogenic responses due to local cytokine accumulations such as occur in the wall of arteries in the presence of hypertension, hypercholesterolemia, accumulation of lipids, extravasated blood products (e.g., red blood cells, macrophages, inflammatory products) which attract monocytes, and response of vasa vasorum to pharmacological stimuli.
KEYWORDS Angiogenesis; Arteries; Atherosclerosis; Coronary disease; Inflammation
| 1. Introduction |
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Vasa vasorum consist of small arteries which enter the vascular wall either from the abluminal surface (vasa vasorum externa) or from the luminal surfaces (vasa vasorum interna) and then arborize to the outer media. Venous vasa vasorum drain a network of capillaries/venules laid down around the outer media to veins in close proximity to the arteries. In humans, vessels with walls less than 29-cell layers thick [1] normally do not have vasa [2] and, in general, vessels less than 0.5mm lumen diameter [3] (all normal vessels in mice and intramyocardial vessels in humans) do not have vasa vasorum. In larger vessels diffusion of solutes to the media from the vessel lumen is supplemented by vasa vasorum [4,5].
The vasa vasorum have been the subject of considerable interest for more than a century [6] because of their possible role in, atherogenesis [7–12], coronary interventions [13–15], and in response to risk factors for atherosclerosis, such as hypercholesterolemia [16–20] and hypertension [21–23]. Although many studies have described the anatomy of the vasa vasorum in a qualitative manner [24–28], the more recently described detailed 3D architecture of the vasa vasorum network (due to the availability of micro-CT imaging capabilities [29,30]) has made more quantitative information available. In addition, it is becoming increasingly clear that vasa vasorum are dynamic in that they can be transiently compressed by the surrounding arterial wall and/or undergo vasodilation and vasoconstriction as well as increase in number (e.g., angiogenesis). Thus, these capabilities of the vasa vasorum underscore their dynamic role in the regulation of vascular wall perfusion (Table 1).
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| 2. Anatomy and function of vasa vasorum |
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2.1 Vasa vasorum branching geometry
The vasa vasorum have been shown to function as end arteries [30], possibly due to the pressure distribution within the arterial wall which could compress most of the vasa vasorum. An arterial injection of the silicon polymer Microfil® results in high pressure in the arterial lumen and consequently within the arterial wall consistent with Lame's Law [31]. This intramural pressure gradient can result in compression of some of the vasa vasorum. As illustrated in Fig. 1, this phenomenon is demonstrated when Microfil® is injected into the concomitant vein so that the coronary artery is filled retrogradely via the intramyocardial capillaries and the arterial vasa vasorum are filled retrogradely via the venous vasa vasorum which empty directly into the concomitant vein and are therefore also exposed to the Microfil® injection pressure. Hence, the luminal pressure in the artery is much reduced, resulting in a less distended coronary arterial lumen and the compressive force within the arterial wall is proportionally decreased. This in turn results in less compression of the vasa vasorum in the arterial wall because they are both exposed to the increased pressure in the vasa vasorum as well as to the reduced intramural pressure. Consequently, the density of perfused (and therefore opacified) vasa vasorum under these conditions is increased.
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Due to the vasa vasorum both the vascular adventitia and, to a lesser extent, the media are brought into close proximity to blood cells and blood solutes. Because the blood pressure within the main arterial lumen is generally higher than the extra-vascular tissue pressure, the diffusion of the blood solutes would tend to be from the main lumen towards the adventitia, as described by Darcy's Law [32] which links diffusion of a solute through a porous medium subjected to a pressure gradient. The only way that those solutes can leave the vessel wall is via the venous vasa vasorum and any lymphatics that may be present in the wall.
The branching structures of the vasa vasorum have also been explored [4,33,34], but little has been done to use that structure to explore the fluid dynamic conductive characteristics of the vasa vasorum [29,30,35].
An important consequence of the anatomic location and branching architecture of the vasa vasorum, which enter the arterial wall via the adventitia, is that flow through the vasa cannot proceed far into the media due to the compressive force (Pw) within the arterial wall, at location R, as described by Lamé's Law [31]:
Where: P
is the pressure in the coronary artery lumen, a is the radius of coronary artery lumen, b is the radius of the outer adventitia, R is the radial distance (from the endothelial surface) within the coronary arterial wall.
This law indicates that the local compressive pressure within the vessel wall is equal to lumenal blood pressure in the sub-endothelial layer (i.e., R
a) but falls-off hyperbolically towards to adventitia (i.e., R
b). As a consequence, at the radial location at which the pressure inside the parent vessel wall exceeds the pressure in the vasa vasorum lumen (determined largely by pressure drop (
Pi) along the vasa vasorum as described by Poiseuille's Law [36]), no perfusion of the wall can occur closer to the main lumen.
Where: Pi is the pressure in the lumen of the vasa vasorum at distance L from the origin of the vasa vasorum. Where: ri is the radius of the proximal vasa vasorum lumen and Li is the distance along the vasa vasorum to the point-of-interest within the wall.
The vascular resistance to flow in the vasa vasorum is high because the radii of the vasa vasorum are much smaller than the parent vessel lumen, hence the pressure within the distal vasa vasorum close to the media must be lower than the coronary arterial lumen pressure hence this intima-medial zone must be where the compressive pressure within the wall can exceed the blood pressure within the vasa vasorum at that location. However, these considerations assume a steady state. It is conceivable that as the systolic pressure pulse progresses along the vasa vasorum its arrival in the terminal vasa vasorum is delayed relative to the transient increase of systolic pressure propagated within the arterial wall. Consequently, the extent of transmural perfusion by vasa vasorum may be underestimated by a steady-state assumption.
Darcy's Law [32] describes the driving force for diffusion of extra-vascular solutes to migrate across a vessel wall in the direction of the pressure gradient within the wall.
Where: f
and fvv are the fluxes of solutes from the coronary arterial lumen and into the venous vasa vasorum respectively. Area
is the coronary arterial endothelial surface area across which solute flux occurs and Areavv being the area of the vasa endothelial surface within the wall at distance R within the wall. T is the distance from the endothelium towards the outer surface of the adventitia (i.e., R–a).
This law implies that for the venous vasa vasorum to match the flux across the main lumen's endothelium, the venous vasa vasorum endothelial permeability surface area product must be large enough to cope with this transmural flux from the main lumen. Thus, ligating the venous vasa vasorum should result in build-up of solutes such as fatty compounds [7,11,37].
As veins also have vasa vasorum [38,39], it is of interest that veins generally do not develop atherosclerosis except when they are exposed to increased lumen pressure. This is observed when they are used as arterial shunts (such as saphenous vein bypass grafts [40–42]) which often undergo accelerated intimal thickening and plaque formation after three years. Although the accelerated venous atherosclerosis may in part be due to damage to the vasa vasorum at the time of harvesting and transplant of the vein segment, the combination of the presence of vasa and high intra-vascular blood pressure [42,43] or very high plasma lipid concentrations [44] appear to be necessary for development of atherosclerotic plaques.
The "footprints" of coronary vasa vasorum perfusion territories (Fig. 2) have also been studied [30]. Microembolization reduced vasa vasorum densities significantly and increased the size of low-vasa-vasorum-density territories. Consequently, under normal conditions coronary vasa vasorum are functional end arteries, even though they may end up being connected via an anatomic plexus. This characteristic may have a significant impact on the spatial distribution of perfusion and drainage of the coronary vessel wall. If the heterogeneous distribution of both coronary atherosclerosis and of the vasa vasorum along the coronary vascular tree are anatomically coincident, this would more directly support the potential role of the vasa vasorum in the disease process.
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2.2 Physiologic reactivity of vasa vasorum
The proximal vasa vasorum display a regularly layered vascular structure of endothelial cells, vascular smooth muscle cells, and surrounding connective tissue. These characteristics are important since they imply that the vasa vasorum may regulate their own tone and vascular perfusion [5,45,46] in a manner similar to small coronary arteries, as was demonstrated by Scotland et al. [47,48].
Vasa vasorum, isolated from porcine aorta, respond to the endothelium-dependent vasodilators substance P and bradykinin similar to the host vessel response. Although vascular reactivity of the vasa vasorum in different vascular beds is not known, any differences in reactivity conceivably contribute to the different susceptibilities of different vascular beds, (such as coronary versus peripheral arteries) to atherosclerosis [49–51].
2.3 Role of the vasa vasorum in solute transport into and from arterial wall
The transport physiology of aortic vasa vasorum has been explored using radiolabeled microsphere-based estimates of perfusion [5] as well as the oxygenation of the arterial wall by direct measurement [52,53] and by model-based analysis of oxygen tension [54]. These approaches show a nadir of oxygen tension of approximately 10mmHg at about 300µm from the lumen. Lipid transport by vasa vasorum into the parent vessel wall has been shown to be about 30% of the transintimal transport in rabbit aorta [55].
| 3. Role of the vasa vasorum in atherosclerosis |
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Several interacting feedback loops that plausibly involve vasa vasorum during the development of atherosclerotic plaques are provided in (Fig. 3). The relative magnitude and timing of the activation and/or suppression of these feedback loops would largely determine, 1) the rate of development of plaques [56] and 2) the stability of those plaques [57].
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3.1 Modification of transport into and out of vascular wall
That endothelial injury and dysfunction are early features of atherosclerosis is supported by numerous experimental findings [58]. However, the hypothesis that "injured" endothelium is a causative factor begs the question as to why early atherosclerosis is not observed in small arteries, in the outer media (where vasa vasorum endothelium is present) or in undisturbed veins.
Studies involving measurement of the transport of lipids and albumin and dyes into the wall from the main lumen [44,59] generally do not consider the possible role of vasa vasorum [60] but focused exclusively on the influx of solute, endothelial permeability and local solute residence times or heat removal/delivery. Moreover, these studies also did not address the possibility that there may be circumferential variations in transmural pressure gradient. Thus, a region of wall that is not supported at its abluminal surface would have a larger pressure gradient (which would drive diffusion into the wall via Darcy's Law) than would wall that is supported on its abluminal surface.
The reason veins and the normal pulmonary artery do not develop atherosclerosis may be due to the fact that the transmural flux of solute (as described by Darcy's Law) is diminished due to the low venous and pulmonary artery lumen pressures. In addition, with these lumen pressures generally being lower than the pressure within the arterial vasa vasorum, these vasa vasorum may never be compressed during the entire cardiac cycle, thereby maintaining adequate flow in the vasa vasorum. Nonetheless, the need for a high density of external vasa vasorum in vein walls is likely due to the fact that the venous (unlike arterial) blood in the main lumen provides little, if any, oxygen to the wall via transendothelial diffusion from the main lumen.
The early stages of histologically detectable atherogenesis have been shown to involve increased transport of low density lipoprotein (LDL) across the endothelium, preceding cellular infiltration/ proliferation in the arterial wall [61–64]. Because of endothelial dysfunction in arterial vasa vasorum, delivery of LDL (and probably oxidized and inflammatory products) may occur at a rate greater than can be removed by venous vasa vasorum [17]. In addition to the increased delivery (or impaired removal) of LDL from the arterial wall by the arterial vasa vasorum [65], an early major focus on the vasa vasorum's possible role in atherogenesis has been the oxygen delivery [66–68]. Low oxygen tension has been shown to accelerate atherogenesis and interfere with LDL transport [69]. Moreover, fatty streaks, especially in diabetic situations, have been shown to increase oxygen demand [70]. We speculate that these data suggest the presence of a positive feedback process so that reduced perfusion from the vasa vasorum results in local hypoxia and in increased accumulation of fatty substances in the intima/media, which, in turn, results in further local hypoxia due to the increased local oxygen consumption.
3.2 Modification of the vasa vasorum function by neovascularization
Despite the fact that atherosclerosis encroaches on the arterial lumen only at its late stage, the majority of research efforts continue to focus on the luminal side of the vascular wall. Recent evidence, however, suggests that the adventitia may play a significant role in maintaining vessel integrity, and may contribute to the initiation and/or progression of certain types of vascular disease [71,72]. Indeed, experimental studies demonstrated that manipulation of the adventitia, and more specifically of the vasa vasorum, such as handling of the vessels at surgery or deposits of talcum powder from the gloves, could lead to atherosclerotic changes of the intima [7,11,12,73,74]. Atherosclerotic lesion formation is associated with neovascularization of the vasa vasorum [30,75,76] as illustrated in (Fig. 4).
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A number of autopsy-based studies highlighted that this neovascularization process occurs in the neointima, which progresses with and determines plaque extent [77]. The latter aspect was underscored by an experimental study in apoE-deficient mice, showing that anti-angiogenic therapy not only reduced plaque neovascularization but eventually plaque growth [78]. Moreover, the inhibition of angiogenesis was associated with a reduction of macrophages in the plaque and around the vasa vasorum [79–81].
3.3 Alteration of the vasa vasorum endothelial function by disease
Hypercholesterolemia and hypertension are associated with impaired endothelial function and an increase in vascular inflammation such as indicated by increased expression of the nuclear transcription factor kappaB (NF-
B) [82]. In addition, an increase of NF-
B has been shown to cause enhanced endothelial cell apoptosis [83]. Endothelial dysfunction and an increase in the vascular tone of the vasa vasorum may be enhanced in these states due to the enhanced inflammation and the reduction in the bioavailability of nitric oxide, secondary to the increase in endogenous oxidative stress. Eventually, these alterations in the balance of vasoreactive factors and endothelial cell function may lead to the functional reduction in blood flow to the vascular wall and local hypoxia potentially resulting in vasa vasorum neovascularization to meet the perfusion needs of the arterial wall. The imbalance between vascular nutrient supply and demand might even be worsened by an enhanced metabolism and/or size of the vascular wall upon exposure to a cardiovascular risk factor. This relates to the hypoxia or anoxemia theory of atherosclerosis [84]. Indeed, recent studies in hypertensive rats demonstrated increase in hypoxia-inducible factor 1 alpha (HIF-1
) and VEGF expression in the aorta, which was subsequently followed by increase in vasa vasorum density around the aorta [23]. A similar increase in HIF-1
and VEGF has been demonstrated in coronary arteries in hypercholesterolemic pigs [85]. This study also indicated that the reversibility of endothelial dysfunction at the early stages of atherosclerosis was associated with a parallel reduction in the coronary vasa vasorum spatial density (neovascularization). Vasa vasorum neovascularization has also been shown to precede the development of atherosclerotic lesion and even the impairment of endothelium-dependent vaso-relaxation, a hallmark of early atherosclerosis [17]. Hence, there seems to be an interaction between the pathophysiologic state of the vessel and the vasa vasorum spatial density, which is a dynamic, not a static, process.
The reduction in vascular wall hypoxia coincides with the decrease in the expression of pro-angiogenic factors in the coronary arterial wall [18,19,86]. Thus, preservation of endothelial function of the vasa vasorum and thereby preservation of adventitial blood supply might be a common mechanism of the neovascularization in different vascular beds.
Elevated plasma lipid concentration [87] and coronary artery luminal endothelium damage have been shown to be major factors in the initiation and progression of atherogenesis [88,89]. However, it is plausible that the coronary artery vasa vasorum have an aggregate endothelial surface area that is comparable in size to the host vessel's luminal endothelium, especially in early stages of atherosclerosis, when there is increased density of vasa vasorum [90,91]. Hence, disparity between the luminal and vasa vasorum endothelial surfaces areas may be an important factor. In addition, it seems possible that vasa vasorum blood flow may be selectively reduced by increased smooth muscle tone in proximal vasa vasorum due to reduced endothelial transduction function, infection, inflammation or thrombosis. This would result in hypoxia and reduced removal of substances from the media, which must now accumulate. Despite this possible inequality in anatomic endothelial surface areas it is not clear if the functional surface areas and endothelial permeabilities (i.e., permeability surface area products) at the two sites are comparable and equally susceptible to damage or loss of function. Such mismatch of endothelial function would seem plausible [92]. Importantly, however, the "host artery" endothelium has a high pressure driving substances into the intima whereas the lower luminal pressure in the vasa vasorum (due to the small diameter of these vessels which causes a pressure drop as described by Poiseuille's Law) creates a pressure gradient which favors solute transport from host artery lumen towards the adventitia as described by Darcy's Law. Indeed, that it is more likely that substances diffuse into the vasa from the media, rather than the opposite, has been shown by the clearance of radiolabeled molecules [75,93,94].
One of the possible consequences of infiltration of lipids into the subintima or media is that vasa proliferate due to the angiogenic stimulus they generate via the concomitant oxidative stress [95]. Specific angiogenic factors have been shown to play a role in the proliferation of vasa vasorum [93,96–98]. However, the angiogenesis may just not be enough to meet the need for increased endothelial surface area product of the vasa vasorum.
3.4 Role of the vasa vasorum as a portal for cellular invasion of the arterial wall
Neovascularization of the vasa vasorum could conceivably function as a conduit for entry of macrophages and inflammatory factors that may potentially promote the progression of the disease and angiogenesis [79]. Moreover, as increased endothelial permeability and fragility are cardinal features of pathological neovascularization [99] pro-atherogenic cellular and soluble plasma components may enter the vessel wall more easily through ruptured and/or leaky vasa vasorum thereby further enhancing the progression of atherosclerosis [100]. Indeed, there is an increased influx to, as well as a decreased drainage from, the coronary vessel wall in the porcine model of hypercholesterolemia [101]. Pathological and experimental studies are consistent with the contention that vasa vasorum hemorrhage may be a key factor in the development of unstable atherosclerotic lesions [102,103].
Moreno et al. [104] demonstrated that neovascularization, as manifested by the localized appearance of microvessels, is increased in ruptured plaques in the human aorta. Furthermore, they could demonstrate that microvessel density is increased in lesions with inflammation, with intraplaque hemorrhage, and in thin-cap fibroatheromas. A recent study by Langheinrich et al. [76] demonstrates the association among different advanced atherosclerotic lesions, adventitial vasa vasorum neovascularization and adventitial inflammation in apoE–/–/LDL–/–double knockout mice.
| 4. Summary |
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The role of vasa vasorum in maintaining the integrity of the walls of vessels more than 0.5 mm in diameter is not fully understood, although they clearly are present when the wall is thicker than can be maintained viable by diffusion of solutes from the lumen alone. There is clearly a strong association between the density of vasa vasorum in an arterial vessel wall and severity of plaque formation, but it is still not clear whether the vasa vasorum play a causative or merely reactive role. The latter possibility is complicated by the possibility that the development of new vasa vasorum is too late and/or that the new vasa vasorum serve as conduit which facilitates cellular invasion of the vessel wall and thereby impact on the type of plaque formed.
Time for primary review 25 days
| Acknowledgments |
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This manuscript was supported in part by NIH grants, HL65342 and EB000305. We also want to thank Ms. Mara Lukenda for typing and coordinating this manuscript.
| References |
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- Wolinsky H., Glagov S. Nature of species differences in the medial distribution of aortic vasa vasorum in mammals. Circ Res (1967) 20:409–421.
[Abstract/Free Full Text] - Okuyama K., Yagimuna G., Takahashi T., Sasaki H., Mori S. The development of vasa vasorum of the human aorta in various conditions. A morphometric study. Arch Pathol Lab Med (1988) 112:721–725.[Web of Science][Medline]
- Geiringer E. Intimal vascularization and atherosclerosis. J Pathol Bacteriol (1951) 63:201–211.[CrossRef][Web of Science][Medline]
- Zamir M., Silver M.D. Vasculature in the walls of human coronary arteries. Arch Pathol Lab Med (1985) 109:659–662.[Web of Science][Medline]
- Heistad D.D., Marcus M.L. Role of vasa vasorum in nourishment of the aorta. Blood Vessels (1979) 16:225–238.[Web of Science][Medline]
- Koester W. Endarteritis and arteritis. Berl Klin Wochenschr (1876) 13:454–455.
- Nakata Y., Shionoya S. Vascular lesion due to obstruction of the vasa vasorum. Nature (1966) 212:1258–1259.[CrossRef][Web of Science]
- Mann F.D. Vasa vasorum and coronary atherosclerosis. Lancet (1978) 1:1319–1320.[Web of Science][Medline]
- Barger A.C., Beeuwkes R. III, Lainey L.L., Silverman K.J. Hypothesis: vasa vasorum and neovascularization of human coronary arteries. A possible role in the pathophysiology of atherosclerosis. N Engl J Med (1984) 310:175–177.[Web of Science][Medline]
- Barger A.C., Beeuwkes R. III. Rupture of coronary vasa vasorum as a trigger of acute myocardial infarction. Am J Cardiol (1990) 66:41G–43G.[CrossRef][Medline]
- Barker S.G., Talbert A., Cottam S., Baskerville P.A., Martin J.F. Arterial intimal hyperplasia after occlusion of the adventitial vasa vasorum in the pig. Arterioscler. Thromb. (1993) 13:70–77.
[Abstract/Free Full Text] - Barker S.G., Tilling L.C., Miller G.C., Beesley J.E., Fleetwood G., Stavri G.T., et al. The adventitia and atherogenesis: removal initiates intimal proliferation in the rabbit which regresses on generation of a 'neoadventitia'. Atherosclerosis (1994) 105:131–144.[CrossRef][Web of Science][Medline]
- Cragg A.H., Einzig S., Rysavy J.A., Castaneda-Zuniga W.R., Borgwardt B., Amplatz K. The vasa vasorum and angioplasty. Radiology (1983) 148:75–80.
[Abstract/Free Full Text] - Kwon H.M., Sangiorgi G., Ritman E.L., Lerman A., McKenna C., Virmani R., et al. Adventitial vasa vasorum in balloon injured coronary arteries: visualization and quantitation by a microscopic three-dimensional computed tomography technique. J Am Coll Cardiol (1998) 32:2072–2079.
[Abstract/Free Full Text] - Sanada J.I., Matsui O., Yoshikawa J., Matsuoka T. An experimental study of endovascular stenting with special reference to the effects on the aortic vasa vasorum. Cardiovasc. Interv. Radiol. (1998) 21:45–49.[CrossRef][Web of Science][Medline]
- Kwon H.M., Sangiorgi G., Ritman E.L., McKenna C., Holmes D.R. Jr., Schwartz R.S., et al. Enhanced coronary vasa vasorum neovascularization in experimental hypercholesterolemia. J Clin Invest (1998) 101:1551–1556.[Web of Science][Medline]
- Herrmann J., Lerman L.O., Rodriguez-Porcel M.G., Holmes D.R. Jr., Richardson D.M., Ritman E.L., et al. Coronary vasa vasorum neovascularization precedes epicardial endothelial dysfunction in experimental hypercholesterolemia. Cardiovasc. Res. (2001) 51:762–766.
[Abstract/Free Full Text] - Herrmann J., Best P.J., Ritman E.L., Holmes D.R., Lerman L.O., Lerman A., et al. Chronic endothelin receptor antagonism prevents coronary vasa vasorum neovascularization in experimental hypercholesterolemia. J Am Coll Cardiol (2002) 39:1555–1561.
[Abstract/Free Full Text] - Wilson S.H., Simari R.D., Best P.J., Peterson T.E., Lerman L.O., Aviram M., et al. Simvastatin preserves coronary endothelial function in hypercholesterolemia in the absence of lipid lowering. Arterioscler. Thromb. Vasc. Biol. (2001) 21:122–128.
[Abstract/Free Full Text] - Cheema A.N., Hong T., Nili N., Segev A., Moffat J.G., Lipson K.E., et al. Adventitial microvessel formation after coronary stenting and the effects of SU11218, a tyrosine kinase inhibitor. J Am Coll Cardiol (2006) 47:1067–1075.
[Abstract/Free Full Text] - Marcus M.L., Heistad D.D., Armstrong M.L., Abboud F.M. Effects of chronic hypertension on vasa vasorum in the thoracic aorta. Cardiovasc Res (1985) 19:777–781.
[Abstract/Free Full Text] - Kai H., Kuwahara F., Tokuda K., Shibata R., Kusaba K., Niiyama H., et al. Coexistence of hypercholesterolemia and hypertension impairs adventitial vascularization. Hypertension (2002) 39:455–459.
[Abstract/Free Full Text] - Kuwahara F., Kai H., Tokuda K., Shibata R., Kusaba K., Tahara N., et al. Hypoxia-inducible factor-1alpha/vascular endothelial growth factor pathway for adventitial vasa vasorum formation in hypertensive rat aorta. Hypertension (2002) 39:46–50.
[Abstract/Free Full Text] - Winternitz M.D., Thomas R.M., LeCompte P.M. The biology of arteriosclerosis. (1938) Springfield, IL: Charles C. Thomas Publisher.
- Schoenenberger F., Mueller A. Ueber die Vaskularisierung der Rinderaortenwand. Helv Physiol Pharmacol Acta (1960) 18:136–150.[Medline]
- Nakata Y., Shionoya S., Tamura J., Hirabayashi N. Vasa vasorum and vascular lesions in the human abdominal aorta. Vasa (1977) 6:255–258.[Web of Science][Medline]
- Stefanadis C., Vlachopoulos C., Karayannacos P., Boudoulas H., Stratos C., Filippides T., et al. Effect of vasa vasorum flow on structure and function of the aorta in experimental animals. Circulation (1995) 91:2669–2678.
[Abstract/Free Full Text] - Angouras D., Sokolis D.P., Dosios T., Kostomitsopoulos N., Boudoulas H., Skalkeas G., et al. Effect of impaired vasa vasorum flow on the structure and mechanics of the thoracic aorta: implications for the pathogenesis of aortic dissection. Eur J Cardio-thorac Surg (2000) 17:468–473.
[Abstract/Free Full Text] - Gössl M., Rosol M., Malyar N.M., Fitzpatrick L.A., Beighley P.E., Zamir M., et al. Functional and hemodynamic characteristics of vasa vasorum in the walls of porcine coronary arteries. Anat Rec (2003) 272A:526–537.[Medline]
- Gössl M., Malyar N.M., Rosol M., Beighley P.E., Ritman E.L. Impact of coronary vasa vasorum functional structure on coronary vessel wall perfusion distribution. Am J Physiol Heart Circ Physiol (2003) 285:H2019–H2026.
[Abstract/Free Full Text] - Den Hartog J.P. Strength of materials. (1949) New York: Dover Publications, Inc. 323.
- Bear J. Dynamics of fluids in porous media. (1972) New York: Dover Publications, Inc. 764.
- Phillips G.D., Stone A.M., Schultz J.C., Whitehead R.A., Jones B.D., Goodkin M.L., et al. Age-related alterations in the morphology of femoral artery vasa vasorum in the rat. Mech Ageing Dev (1995) 82:149–154.[CrossRef][Web of Science][Medline]
- Okuyama K., Yoegashi H., Takahashi T., Sasaki H., Mori S. The three dimensional architecture of vasa vasorum in the wall of the human aorta. A computer aided reconstruction study. Arch Pathol Lab Med (1988) 112:726–730.[Web of Science][Medline]
- Gössl M., Zamir M., Ritman E.L. Vasa vasorum growth in the coronary arteries of newborn pigs. Anat Embryol (2004) 208:351–357.[Medline]
- Considine D.M., ed. Van Nostrand's scientific encyclopedia. (1976) 5th edition. NY: Van Nostrand Reinhold Co. 2370.
- Nakata Y., Shionoya S. An experimental study on the vascular lesions caused by obstruction of vasa vasorum (II). Special consideration on deposition of fat into vascular wall. Japanese Circ J (1970) 269:804–806.
- Heistad D.D. Blood flow through vasa vasorum in arteries and veins: effect of luminal pO2. Am J Physiol Heart Circ Physiol (1986) 250:H434–H442.
[Abstract/Free Full Text] - Heistad D.D., Marcus M.L., Law E.G., Armstrong M.L., Ehrhardt J.C., Abboud F.M. Regulation of blood flow to the aortic media in dogs. J Clin Invest (1978) 62:133–140.[Web of Science][Medline]
- Motwani J.G., Topol E.J. Aortocoronary saphenous vein graft disease. Pathogenesis and prevention. Circulation (1998) 97:916–931.
[Abstract/Free Full Text] - Davies M.G., Hagen P.O. Pathophysiology of vein graft failure: A review. Eur J Vasc Endovasc Surg (1995) 9:7–18.[CrossRef][Web of Science][Medline]
- Watelet J., Soury P., Menard J.F., Plissonnier D., Peillon C., Lestrat J.P., et al. Femoropopliteal Bypass: in situ or reversed vein grafts? Ten-year results of a randomized prospective study. Am Vasc Surg (1997) 11:510–519.[CrossRef]
- Dashwood M.R., Anand R., Loesch A., Souza D.S. Hypothesis: a potential role for the vasa vasorum in the maintenance of vein graft patency. Angiology (2004) 55:385–395.
[Abstract/Free Full Text] - Tarbell J.M. Mass transport in arteries and the localization of atherosclerosis. Annu Rev Biomed Eng (2003) 5:79–118.[Medline]
- Scotland R.S., Vallance P.J., Ahluwalia A. Endogenous factors involved in regulation of tone of arterial vasa vasorum: implications for conduit vessel physiology. Cardiovasc Res (2000) 46:403–411.
[Abstract/Free Full Text] - Heistad D., Marcus M., Martin J. Effects of neural stimuli on blood flow through vasa vasorum in dogs. Circ Res (1979) 45:615–620.
[Abstract/Free Full Text] - Scotland R.S., Vallance P., Ahluwalia A. On the regulation of tone in vasa vasorum. Cardiovasc Res (1999) 41:237–245.
[Abstract/Free Full Text] - Scotland R.S., Vallance P.J.T., Ahluwalia A. Endothelin alters the reactivity of vasa vasorum: mechanisms and implications for conduit vessel physiology and pathophysiology. Br J Pharmacol (1999) 128:1229–1234.[CrossRef][Web of Science][Medline]
- Nikol S., Pelisek J., Engelmann M.G., Shimizu M., Fuchs A., Golda A., et al. Vascular endothelial growth factor (VEGF165) and its influence on angiogenesis versus arteriogenesis in different vascular beds. J Endovasc Ther (2002) 9:842–854.[CrossRef][Web of Science][Medline]
- Nikol S., Engelmann M.G., Pelisek J., Fuchs A., Golda A., Shimizu M., et al. Local perivascular application of low amounts of a plasmid encoding for vascular endothelial growth factor (VEGF165) is efficient for therapeutic angiogenesis in pigs. Acta Physiol Scand (2002) 176:151–159.[CrossRef][Web of Science][Medline]
- Galili O., Herrmann J., Woodrum J., Sattler K.J., Lerman L.O., Lerman A. Adventitial vasa vasorum heterogeneity among different vascular beds. J Vasc Surg (2004) 40:529–535.[CrossRef][Web of Science][Medline]
- Crawford D.W., Back L.H., Cole M.A. In vivo oxygen transport in the normal rabbit femoral arterial wall. J Clin Invest (1980) 65:1498–1508.[Web of Science][Medline]
- Buerk D.G., Goldstick T.K. Arterial wall oxygen consumption rates vary spatially. Am J Physiol Heart Circ Physiol (1982) 243:H948–H958.
[Abstract/Free Full Text] - Schneiderman G., Mockros L.F., Goldstick T.K. Effect of pulsatility on oxygen transport to the human arterial wall. J Biomech (1982) 15:849–858.[CrossRef][Web of Science][Medline]
- Bratzler R.L., Chisolm G.M., Colten C.K., Smith K.A., Lees R.S. The distribution of low density lipoproteins across the rabbit thoracic aorta in vivo. Atherosclerosis (1977) 28:289–307.[CrossRef][Web of Science][Medline]
- Doyle B., Caplice N. Plaque neovascularization and antiangiogenic therapy for atherosclerosis. J Am Coll Cardiol (2007) 49:2073–2080.
[Abstract/Free Full Text] - Kolodgie F.D., Narula J., Yuan C., Burke A.P., Finn A.V., Virmani R. Elimination of neoangiogenesis for plaque stabilization: is there a role for local drug therapy? J Am Coll Cardiol (2007) 49:2093–2101.
[Abstract/Free Full Text] - Ross R. The pathogenesis of atherosclerosis: an update. N Engl J Med (1986) 314:488–500.[Web of Science][Medline]
- Goldstick T.K., Dobrin P.B. Handbook of bioengineering. Skalak R., Chien S., eds. (1987) 22. New York: McGraw-Hill Book Company. 1–11.
- Shou Y., Jan K.M., Rumschitzki D.S. Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia. Am J Physiol Heart Circ Physiol (2006) 291:H2758–H2771.
[Abstract/Free Full Text] - Liu S.J., Jan K.M., Weinbaum S., Chien S. Transendothelial transport of low density lipoprotein in association with cell mitosis in rat aorta. Arteriosclerosis (1989) 9:230–236.
[Abstract/Free Full Text] - Yin Y., Liu K.H., Weinbaum S., Chien S., Rumschitz D.S. A model for the initation and growth of extra cellular lipid liposomes in arterial intima. Am J Physiol Heart Circ Physiol 41 (1997) 272:H1033–H1036.
[Abstract/Free Full Text] - Wu C.H., Chi J.C., Jerug J.S., Lin S.J., Jan K.M., Wang D.L., et al. Transendothelial macromolecular transport in the aorta of spontaneously hypertensive rats. Hypertension (1990) 16:154–161.
[Abstract/Free Full Text] - Simionescu N., Vasile E., Lupu F., Popescu G., Simionescu M. Prelesional events in atherosclerosis. Am J Pathol (1986) 123:109–125.[Abstract]
- Adams C.W.M., Bayliss O.B. The relationship between diffuse intimal thickening, medial enzyme failure and intimal lipid deposition in various human arteries. J Atheroscler Res (1969) 10:327–339.[Web of Science][Medline]
- Hueper W.C. Arteriosclerosis: the anoxemia theory. Arch Pathol (1944) 38:162–181.
- Hueper W.C. Arteriosclerosis: the anoxemia theory. Vasotonia: B Hypertonia followed by constriction anoxemia; agents and influences producing it. Arch Pathol (1944) 38:245–285.
- Hueper W.C. Arteriosclerosis: the anoxemia theory. Renal hypertension and essential hypertension. Arch Pathol (1944) 38:350–364.
- Getz G.S., Vesselinovitch D., Wissler R.W. A dynamic pathology of atherosclerosis. Am J Med (1969) 46:657–673.[CrossRef][Web of Science][Medline]
- Morrison A.D., Clements R.S. Jr., Weingrad A.T. Effects of elevated glucose concentrations on the metabolism of the aortic wall. J Clin Invest (1972) 51:3114–3123.[Web of Science][Medline]
- Wilcox J.N., Scott N.A. Potential role of the adventitia in arteritis and atherosclerosis. Int J Cardiol (1996) 54:S21–S35.[CrossRef][Web of Science][Medline]
- Barker S.G., Beesley J.E., Baskerville P.A., Martin J.F. The influence of the adventitia on the presence of smooth muscle cells and macrophages in the arterial intima. Eur J Vasc Endovasc Surg (1995) 9:222–227.[CrossRef][Web of Science][Medline]
- Booth R.F., Martin J.F., Honey A.C., Hassall D.G., Beesley J.E., Moncada S. Rapid development of atherosclerotic lesions in the rabbit carotid artery induced by perivascular manipulation. Atherosclerosis (1989) 76:257–268.[CrossRef][Web of Science][Medline]
- Martin J.F., Booth R.F., Moncada S. Arterial wall hypoxia following hyperfusion through the vasa vasorum is an initial lesion in atherosclerosis. Eur J Clin Invest (1990) 20:588–592.[Web of Science][Medline]
- Zhang Y., Cliff W.J., Schoefl G.I., Higgins G. Immunohistochemical study of intimal microvessels in coronary atherosclerosis. Am J Pathol (1993) 143:164–172.[Abstract]
- Langheinrich A.C., Michniewiz A., Sedding D.G., Walker G., Beighley P.E., Rau W.S., et al. Correlation of vasa vasorum neovascularization and plaque progression in aortas of apoE–/–/LDL–/– double knockout mice. Arterioscler Thromb Vasc Biol (2006) 26:347–352.
[Abstract/Free Full Text] - Kumamoto M., Nakashima Y., Sueishi K. Intimal neovascularization in human coronary atherosclerosis: its origin and pathophysiological significance. Hum Pathol (1995) 26:450–456.[CrossRef][Web of Science][Medline]
- Moulton K.S., Heller E., Konerding M.A., Flynn E., Palinski W., Folkman J. Angiogenesis inhibitors endostatin or TNP-470 reduce intimal neovascularization and plaque growth in apolipoprotein E-deficient mice. Circulation (1999) 99:1726–1732.
[Abstract/Free Full Text] - Moulton K.S., Vakili K., Zurakowski D., Soliman M., Butterfield C., Sylvin E., et al. Inhibition of plaque neovascularization reduces macrophage accumulation and progression of advanced atherosclerosis. Proc Natl Acad Sci U S A (2003) 100:4736–4741.
[Abstract/Free Full Text] - Gössl M., Versari D., Mannheim D., Lerman L.O., Lerman A. Inhibition of vasa vasorum neovascularization prevents vessel wall inflammation and intimal hyperplasia in early atherosclerosis. Circulation (Oct. 31 2006) 114(18 Suppl):186. (Abstract).[CrossRef]
- Williams J.K., Armstrong M.L., Heistad D.D. Vasa vasorum in atherosclerotic coronary arteries: responses to vasoactive stimuli and regression of atherosclerosis. Circ Res (1988) 62:515–523.
[Abstract/Free Full Text] - Wilson S.H., Caplice N.M., Simari R.D., Holmes D.R. Jr., Carlson P.J., Lerman A. Activated nuclear factor-kappaB is present in the coronary vasculature in experimental hypercholesterolemia. Atherosclerosis (2000) 148:23–30.[CrossRef][Web of Science][Medline]
- Matsushita H., Morishita R., Nata T., Aoki M., Nakagami H., Taniyama Y., et al. Hypoxia-induced endothelial apoptosis through nuclear factor-kappaB (NF-kappaB)-mediated bcl-2 suppression: in vivo evidence of the importance of NF-kappaB in endothelial cell regulation. Circ Res (2000) 86:974–981.
[Abstract/Free Full Text] - Gainer J.L. Hypoxia and atherosclerosis: re-evaluation of an old hypothesis. Atherosclerosis (1987) 68:263–266.[CrossRef][Web of Science][Medline]
- Wilson S.H., Herrmann J., Lerman L.O., Holmes D.R. Jr., Napoli C., Ritman E.L., et al. Simvastatin preserves the structure of coronary adventitial vasa vasorum in experimental hypercholesterolemia independent of lipid lowering. Circulation (2002) 105:415–418.
[Abstract/Free Full Text] - Best P.J., McKenna C.J., Hasdai D., Holmes D.R. Jr., Lerman A. Chronic endothelin receptor antagonism preserves coronary endothelial function in experimental hypercholesterolemia. Circulation (1999) 99:1747–1752.
[Abstract/Free Full Text] - Steinberg D. Lipoprotein and atherosclerosis. A look back and a look ahead. Arteriosclerosis (1983) 3:283–301.
[Free Full Text] - Fuster V, Badimon L, Badimon J.J, Chesebro J.H. The pathogenesis of coronary artery disease and the acute coronary syndromes (1 & 2). N Engl J Med 326;1992:242-250 and 1992;326:310-8.
- Busse R., Fleming I. Endothelial dysfunction in atherosclerosis. J Vasc Res (1996) 33:181–194.[Web of Science][Medline]
- Kahlon R., Shapero J., Gotlieb A.I. Angiogenesis in atherosclerosis (Review). Can J Cardiol (1992) 8:60–64.[Web of Science][Medline]
- Heistad D.D. Blood flow through vasa vasorum of coronary arteries in atherosclerotic monkeys. Arteriosclerosis (1986) 6:326–331.
[Abstract/Free Full Text] - Rubin K., Hansson G.K., Ronnstrand L., Claesson-Weksesh L., Heldin C.H., Terracio L. Induction of B-type receptors for platelet derived growth factor in vascular inflammation: Possible implications for development of vascular proliferative lesions. Lancet (1988) I:1353–1356.
- Nordestgaad B.G., Hjelms E., Stender S., Kjeldsen K. Different efflux pathways for high and low density lipoproteins from porcine aortic intima. Arteriosclerosis (1990) 10:477–485.
[Abstract/Free Full Text] - Werber A.H., Heistad D.D. Diffusional support of the thoracic aorta in atherosclerotic monkeys. Atherosclerosis (1987) 68:123–130.[CrossRef][Web of Science][Medline]
- Tufro-McReddie A., Norwood V.F., Aylor K.W., Botkin S.J., Carey R.M., Gomey R.A. Oxygen regulates vascular endothelial growth factor-mediated vasculogenesis and tubulogenesis. Dev Biol (1997) 1B3:139–149.
- SoRelle R. Two sides of same coin. Stop angiogenesis for cancer and encourage it for coronary artery disease. Circulation (1998) 98:383–384.
[Free Full Text] - Robert N.E., Palade G.E. Increased microvascular permeability and endothelial fenestration induced by vascular endothelial growth factor. J Cell Sci (1995) 108:2369–2379.[Abstract]
- DAmato R.J., Loughnan M.S., Flynn E., Folkman J. Thalidomide is an inhibitor of angiogenesis. Proc Natl Acad Sci U S A (1994) 91:4082–4085.
[Abstract/Free Full Text] - Bates D.O., Harper S.J. Regulation of vascular permeability by vascular endothelial growth factors. Vasc Pharmacol (2002) 39:225–237.[CrossRef]
- Nielsen L.B. Atherogenecity of lipoprotein (a) and oxidized low density lipoprotein: insight from in vivo studies of arterial wall influx, degradation and efflux. Atherosclerosis (1999) 143:229–243.[CrossRef][Web of Science][Medline]
- Gössl M., Beighley P.E., Malyar N.M., Ritman E.L. Role of vasa vasorum in transendothelial solute transport in the coronary vessel wall: a study with cryostatic micro-CT. Am J Physiol Heart Circ Physiol (2004) 287:H2346–H2351.
[Abstract/Free Full Text] - Kolodgie F.D., Gold H.K., Burke A.P., et al. Intraplaque hemorrhage and progression of coronary atheroma. N Engl J Med (2003) 349:2316–2325.
[Abstract/Free Full Text] - O'Brien K.D., McDonald T.O., Chait A., Allen M.D., Alpers C.E. Neovascular expression of E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 in human atherosclerosis and their relation to intimal leukocyte content. Circulation (1996) 93:672–682.
[Abstract/Free Full Text] - Moreno P.R., Purushothaman K.R., Fuster V., Echeverri D., Truszczynska H., Sharma S.K., et al. Plaque neovascularization is increased in ruptured athero-sclerotic lesions of human aorta: implications for plaque vulnerability. Circulation (2004) 110:2032–2038.
[Abstract/Free Full Text] - Galili O., Sattler K.J., Herrmann J., Woodrum J., Olson M., Lerman L.O., et al. Experimental hypercholesterolemia differentially affects adventitial vasa vasorum and vessel structure of the left internal mammary and coronary arteries. J Thorac Cardiovasc Surg (2005) 129:767–772.
[Abstract/Free Full Text] - Gössl M., Versari D., Mannheim D., Ritman E.L., Lerman L.O., Lerman A. Increased spatial vasa vasorum density in the proximal LAD in hypercholesterolemiaimplications for vulnerable plaque-development. Atherosclerosis (2007) 192:246–252.[CrossRef][Web of Science][Medline]
- Rome J.J., Shoyani V.F., Lugelman M.Y., Newman K.D., Farb A., Virmani R., et al. Anatomic barriers influence the distribution of in vivo gene transfer into arterial wall. Modeling with microscopic tracer particles and verification with recombinant adenoviral vector. Arterioscler Thromb (1994) 14:148–161.
[Abstract/Free Full Text] - Virmani R., Kolodgie F.D., Burke A.P., Finn A.V., Gold H.K., Tulenko T.N., et al. Atherosclerotic plaque progression and vulnerability to rupture: angiogenesis as a source of intraplaque hemorrhage. Arterioscler Thromb Vasc Biol (2005) 25:2054–2061.
[Abstract/Free Full Text] - Langheinrich A.C., Michniewicz A., Sedding D.G., Lai B., Jorgensen S.M., Bohle R.M., et al. Quantitative X-ray imaging of intraplaque hemorrhage in aortas of apoE–/–/LDL–/–double knockout mice. Invest Radiol (2007) 42:263–273.[CrossRef][Web of Science][Medline]
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