Elsevier

Atherosclerosis

Volume 177, Issue 1, November 2004, Pages 37-41
Atherosclerosis

Artery interposed to vein did not develop atherosclerosis and underwent atrophic remodeling in cholesterol-fed rabbits

https://doi.org/10.1016/j.atherosclerosis.2004.06.019Get rights and content

Abstract

Autologous vein grafts interposed to arteries are susceptible to the development of accelerated atherosclerosis. The effect of grafted artery interposed to vein on the atherosclerosis development and vascular remodeling is unknown. We investigated, therefore, the morphologic changes of artery grafts to vein in hyperlipidemic rabbits. Left common carotid artery grafts, approximately 5 cm long, were placed in the right external jugular vein position of 24 New Zealand White rabbits. After surgery, rabbits were fed with high lipid diet for 1, 2, 4 and 12 weeks, respectively. Serum lipid levels were measured and the right common carotid artery and grafted left common carotid artery were harvested at above mentioned time points. Serum lipid levels were also measured in six rabbits receiving normal chow. Vessel wall thickness was measured and analyzed by image processing system. Hyperlipidemia occurred in all rabbits fed with high lipid diet. Fatty streak and atherosclerotic plaques were observed and lipid drops enriched in medial smooth muscle cells in control right common carotid arteries 4 weeks after surgery. In the grafted arteries, no fatty streak and atherosclerotic plaque were seen and the vessel wall thickness decreased continuously after surgery (before surgery: 107.32 ± 4.57 μm; 1 week: 94.50 ± 5.78 μm*; 2 weeks: 87.00 ± 5.32 μm*; 4 weeks: 40.17 ± 5.11 μm*;12 weeks: 18.00 ± 4.93 μm*, *p < 0.05 versus before surgery). Three months after surgery, grafted arteries possess similar structures as that of veins. The artery interposed to vein did not develop atherosclerosis and underwent atrophic remodeling in cholesterol-fed rabbits suggesting that local hemodynamic load was the most important determinant influencing the development of atherosclerosis.

Introduction

Autologous vein grafts remain the main surgical source for many types of vascular reconstruction [1], [2] to replace the diseased arteries although the 1 year occlusion rate of these grafts was as high as more than 20% due to neointima hyperplasia and accelerated graft atherosclerosis [3]. The plaque after vein graft belongs to vulnerable plaque characterized by diffuse intima thickening, abundant foam cell component and sparse intercellular substance [4]. Increased hemoynamic load to grafted vein was supposed to be the main reason for the accelerated vein graft atherosclerosis. To date, little is known about the effect of decreased hemodynamic load for grafted vessel (artery interposed to vein) on the atherosclerosis development and vascular remodeling in atherosclerotic rabbit model. The purpose of the present study is, therefore, to observe the serial changes of grafted common carotid artery (GCCA) interposed to external jugular vein in rabbits fed with high lipid diet.

Section snippets

Materials and methods

Twenty-four male New Zealand white rabbits (Shanghai experiment animal center, Chinese Academy of Sciences) weighing 2.5–3 kg were anesthetized with pentobarbital sodium (30 mg/kg intraperitoneally). Atropine sulfate (1.4 mg/kg, i.p.) was also administered to maintain the respiratory tract dry. The rabbit was fixed in a supine position with its neck extended. A midline incision was made on the ventral side of the neck from the mandible to the sternum. Under a dissecting microscope (SXP1, Shanghai

Serum lipid levels

In rabbits receiving high lipid diet, serum TC, LDL and HDL increased continuously and reached the maximum on the 30th day. TG was increased only in rabbits fed with high lipid diet for 90 days (Table 1). Coefficient of variation ranged from 5.3 to 28.0% for TC, 28.7 to 55.7% for TG, 22.2 to 74.8% for HDL-C and 20.1 to 56.2% for LDL-C.

Light microscope

Vessel wall thickness decreased gradually in CCCA (Fig. 1, open bars, −50% after 12 weeks) and to a great extent, in GCCA (Fig. 1, black bars, −80% after 12 weeks). The fatty streak was seen at 4 weeks (Fig. 2D) and the semilunar atherosclerotic plaque at 12 weeks (Fig. 2E) post surgery in CCCA but not in GCCA (Fig. 2H and I). At 12 weeks post surgery, the vascular wall contains only 2–3 layers of smooth muscle cells in GCCA (Fig. 2I).

Electron microscopy

Fig. 3A shows the long fusiform endothelial cells before

Discussion

The major finding of present study was that the arteries interposed to veins did not develop atherosclerosis and underwent atrophic remodeling, while control right common carotid arteries developed atherosclerosis in cholesterol-fed rabbits. To our knowledge, it is the first time that arteries were interposed into veins in cholesterol-fed rabbits to explore the effect of local hemodynamical load and hyperlipidemia on grafted artery remodeling and sensibility to atherosclerosis.

Both mechanical

Acknowledgement

The study was sponsored by key program of national basic research (G20006903).

References (15)

  • G.D. Angelini et al.

    Time-course of medial and intimal thickening in pig venous arterial grafts: relationship to endothelial injury and cholesterol accumulation

    J. Thorac. Cardiovasc. Surg.

    (1992)
  • C. Napoli et al.

    Fatty streak formation occurs in human fetal aortas and is greatly enhanced by maternal hypercholesterolemia. Intimal accumulation of low-density lipoprotein and its oxidation precede monocyte recruitment into early atherosclerotic lesions

    J. Clin. Invest.

    (1997)
  • R.L. Daiman et al.

    Infrainguinal revascularization procedures

  • J.G. Motwani et al.

    Aortocoronary saphenous vein graft disease: pathogenesis, predisposition, and prevention

    Circulation

    (1998)
  • Y. Guo et al.

    Related problems about atherosclerosis model in high lipid diet rabbit.

  • P. Carmeliet et al.

    Vascular wound healing and neointima formation induced by perivascular electric injury in mice

    Am. J. Pathol.

    (1997)
  • Q. Xu et al.

    Induction of arteriosclerosis in normocholesterolemic rabbits by immunization with heat shock protein 65

    Arterioscler. Thromb.

    (1992)
There are more references available in the full text version of this article.

Cited by (10)

  • Modeling of the effects of IL-17 and TNF-α on endothelial cells and thrombus growth

    2017, Comptes Rendus - Biologies
    Citation Excerpt :

    Arterial thrombosis basically occurs due to the rupture of a atherosclerotic plaque, while venous thromboembolism is mostly related to stasis, hypercoagulation, and endothelial damage [40]. This difference is probably related to different hemodynamic conditions in veins, arteries, including blood flow velocity and blood pressure [41]. In both cases, RA and PsA can trigger endothelial inflammation, resulting in plaque formation in arteries and thromboembolism in veins.

  • Neointimal fibrotic lead encapsulation – Clinical challenges and demands for implantable cardiac electronic devices

    2017, Journal of Cardiology
    Citation Excerpt :

    Chronic renal disease also appears to be an important factor for lead-associated venous mineralization [103]. Mechanical stress is proposed to exacerbate dystrophic tissue mineralization but does not seem to be an obligate trigger [122], while the hemodynamic environment and blood pressure might play an important role [123]. Uremia and diabetes mellitus are associated with arterial calcification [121] and might likewise predispose lead-bearing veins for mineralization.

View all citing articles on Scopus
1

Hongqi Zhang and Aijun Sun contributed equally to this work.

View full text