Humans ; Aortic Aneurysm, Abdominal ; Aorta, Abdominal/pathology* ; Immunity, Innate

BACKGROUNDWith features of high tissue contrast, MRI can be used for the qualitative and quantitative evaluation of atherosclerosis plaques. In this study we investigated the development of atherosclerosis plaque with high resolution 3T MRI in a rabbit model and compared the findings with the histopathological results.

METHODTwenty male New Zealand white rabbits were randomly allocated into an experimental group (n = 16) and a control group (n = 4). Atherosclerotic lesions were induced in the abdominal aorta by balloon injury and cholesterol feeding. Multiple sequences MRI examination (ToF, T1WI, T2WI, and CE T1WI) were performed at the 2nd, 3rd, and 4th months after aortic denudation. Vessel wall thickness, total vessel area, lumen area, and vessel wall area were recorded. Plaque components were analyzed using histological results as a standard reference.

RESULTSSeventeen rabbits (14 in the experimental group and 3 in the control group) received all three MR examinations. Gradually, from 2 months to 4 months, vessel wall thickness and area in the experimental group increased significantly compared with the control group (P < 0.01). In the lumen area progressive stenosis was not found, even a slight dilation had developed in the experimental group. Lipid, fibrotic and calcified plaques can be differentiated by MR image. According to histological results, MRI had good performance in detection of lipid plaque.

CONCLUSIONMRI can be used to monitor progression of atherosclerosis and differentiate plaque components.

Animals ; Aorta, Abdominal ; pathology ; Magnetic Resonance Imaging ; methods ; Male ; Plaque, Atherosclerotic ; pathology ; Rabbits ; Random Allocation

Butylated hydroxytoluene (BHT) can inhibit experimental atherosclerosis in animals. Although the agent is an antioxidant, the exact mechanism of the reaction in atherosclerosis is still unknown. To investigate the effects of BHT on expression of P-selectin (PADGEM, GMP-140), intercellular adhesion molecule-1 (ICAM-1) and class II MHC (Ia) antigen, we proposed an experiment on rats. Male rats (n=18 per group) were fed either a normal cholesterol control diet, a normal cholesterol diet containing 0.5% BHT (BD), a high cholesterol diet containing 1.5% cholesterol and 0.1% sodium cholate (CD), or the CD diet containing 0.5% BHT (BCD). Rats were sacrificed after 3 days, and after 1, 2, 4, 10, and 17 weeks of dietary treatment. Although there was no gross or light microscopic atherosclerotic lesions, scanning electron microscopy revealed monocytic adhesion to aortic endothelium and mild endothelial injuries in CD and BCD groups. Immunohistochemically, the addition of BHT to a high cholesterol diet inhibited P-selectin expression but not in ICAM-1 and Ia antigen. These findings suggest that in rats, high cholesterol diets induce expression of ICAM-1, P-selectin and Ia antigen. In addition, the antiatherogenic effect of BHT may play a role in the inhibition of P-selectin.
Animal ; Antioxidants/pharmacology ; Antioxidants/metabolism* ; Aorta, Abdominal/ultrastructure ; Aorta, Abdominal/pathology ; Aorta, Thoracic/ultrastructure ; Aorta, Thoracic/pathology ; Butylated Hydroxytoluene/pharmacology ; Butylated Hydroxytoluene/metabolism* ; Cholesterol/metabolism ; Cholesterol, Dietary/metabolism* ; Male ; Microscopy, Electron, Scanning ; P-Selectin/biosynthesis* ; Rats ; Rats, Sprague-Dawley

Ischemic injury of the spinal cord is rare complication of infrarenal aortic pathology or procedure. So many vascular surgeons are unfamiliar to this complication. But once developed, the impact of this complication is unendurable not only to the patient and his or her family but also to the surgeon. The importance of great anterior medullary artery was well known. Recently, the role of pelvic collateral circulation has been emerged and stressed. In Korea, spinal cord ischemia related to infrarenal aortic pathology or surgical procedure was not reported until recently. Authors had experienced two paraplegic patients, one after elective aortobifemoral bypass due to aortoiliac occlusive lesion in 49 years old male and the other due to acute thrombotic occlusion of infrarenal aorta in 40 years old male. To inform the possibility of ischemic cord injury in infrarenal aortic procedure and pathology, we report our experiences with review of literatures.
Adult ; Aorta ; Aorta, Abdominal ; Arteries ; Collateral Circulation ; Humans ; Korea ; Male ; Methods* ; Middle Aged ; Paraplegia ; Pathology* ; Spinal Cord Ischemia* ; Spinal Cord*

Aortic intramural hematma(IMH) has been known as a variant of acute aortic dissection without intimal rupture. The clinical presentation mimics that of acute aortic dissection. IMH may progress to frank aortic dissection or aortic rupture. Therefore IMH maybe regarded as early sign of developing classic aortic dissection or a precipitating facter. there are Important two questions, The first is whether IMH truly represent a different pathology or simphy the precursor of the conventtional aortic dissection. The second is what the optimal mode of management of IMH is. In this study, To answer these questions, We retrospectively performed this study. Fifteen patients of IMH were included. We could follow 12 patients. Among them extention of IMH to type III aortic dissection has been observed in 2 cases(1 type A and 1 type B). One patients of type A underwent aortic graft stent deployment successfully. In the other patient of type B, who had a history of myocardial infarction and longstanding heart failure by that time, dissection developed at abdominal aorta with renal arterial involvement. The patient died of multiorgan failure despite intensive conservative managements. The remaining ten patients are alive with only medical care and with good clinical outcome. In conclusion we feel that conservative treatment of patients with IMH result in favorable outcome relatively even in the cases involving the ascending aorta. But more longterm follow-up of larger number of patients will provide better guidelines regarding the proper management of IMH.
Aorta ; Aorta, Abdominal ; Aortic Rupture ; Follow-Up Studies ; Heart Failure ; Hematoma ; Humans ; Myocardial Infarction ; Pathology ; Retrospective Studies ; Rupture ; Stents ; Transplants

Aged, 80 and over ; Aorta, Abdominal ; pathology ; Embolism, Cholesterol ; therapy ; Female ; Humans

BACKGROUNDNoninvasive detection of vulnerable plaque has a significant implication for prevention and treatment of atherosclerotic diseases. The aim of this study is to investigate the difference between vulnerable plaques and stable plaques in magnetic resonance (MR) images.

METHODSAtherosclerosis was induced in twenty male New Zealand white rabbits by high cholesterol diet and balloon injury of the abdominal aorta. After baseline (pre-triggering) MR imaging (MRI) scan, the rabbits underwent pharmaceutical triggering with Russell's viper venom and histamine to induce atherothrombosis, followed by another MRI scan 48 hours later (post-triggering). Rabbits were euthanized to obtain pathological and histological data. The results of MRI were compared with those of pathology and histology.

RESULTSMRI showed that abdominal aorta of the rabbits had pathological change of atherosclerosis in different degrees. Seventy-five plaques were analysed, among which 14 had vulnerable thrombi and 61 stable. Thrombosis was identified in 7 of 11 rabbits by post-triggering MRI, the sensitivity and K value of MR in detection of vulnerable plaque was 71% and 0.803 (P < 0.05). MRI data significantly correlated with the histopathological data in fibrous cap thickness (r = 0.749) plaque area (r = 0.853), lipid core area (r = 0.900). Compared with stable plaques, vulnerable plaques had a significantly thinner fibrous cap ((0.58 ± 0.27) mm vs. (0.95 ± 0.22) mm), larger lipid core area ((7.56 ± 2.78) mm(2) vs. (3.29 ± 1.75) mm(2)), and a higher ratio of lipid core area/plaque area ((55 ± 16)% vs. (27 ± 17)%), but plaque area was comparable in two groups on MRI. The ratio of lipid core area/plaque area was a strong predictor of vulnerable plaques.

CONCLUSIONMRI could distinguish vulnerable plaques from stable plaques in a rabbit model of atherothrombosis and may thus be useful as a noninvasive modality for detection of vulnerable plaques in humans.

Animals ; Aorta, Abdominal ; pathology ; Disease Models, Animal ; Magnetic Resonance Imaging ; methods ; Male ; Plaque, Atherosclerotic ; pathology ; Rabbits ; Thrombosis ; diagnosis

Vascular reactivity can be influenced by the vascular region, animal age, and pathologies present. Prostaglandins (produced by COX-1 and COX-2) play an important role in the contractile response to phenylephrine in the abdominal aorta of young rats. Although these COXs are found in many tissues, their distribution and role in vascular reactivity are not clear. At a vascular level, they take part in the homeostasis functions involved in many physiological and pathologic processes (e.g., arterial pressure and inflammatory processes). The aim of this study was to analyze changes in the contractile response to phenylephrine of thoracic/abdominal aorta and the coronary artery during aging in rats. Three groups of rats were formed and sacrificed at three distinct ages: prepubescent, young and old adult. The results suggest that there is a higher participation of prostanoids in the contractile effect of phenylephrine in pre-pubescent rats, and a lower participation of the same in old rats. Contrarily, there seems to be a higher participation of prostanoids in the contractile response of the coronary artery of older than pre-pubescent rats. Considering that the changes in the expression of COX-2 were similar for the three age groups and the two tissues tested, and that expression of COX-1 is apparently greater in older rats, COX-1 and COX-2 may lose functionality in relation to their corresponding receptors during aging in rats.
Adult ; Aging ; Animals ; Aorta ; Aorta, Abdominal ; Arterial Pressure ; Coronary Vessels ; Heart ; Homeostasis ; Humans ; Pathologic Processes ; Pathology ; Phenylephrine* ; Prostaglandin-Endoperoxide Synthases ; Prostaglandins ; Rats*

Extra-anatomic bypass(EAB) is defined as bypass grafts that pass through a significantly different anatomic pathway than the natural blood vessles they replace. The two categorical reasons for doing this in aortoiliac occlusive disease are to avoid "hostile" intra-abdominal pathologic features and to avoid the high risk of transabdominal reconstruction in patients with serious visceral and systemic disease. To determine the application of this procedure, we reviewed retrospectively the characteristics and outcomes of 30 patients who underwent extra-anatomic bypasses during April, 1986 to April, 1997. Three EABs in brachiocephalic reconstruction were done including 2 carotid-subclavian bypass, 1 femoral-biaxillary bypass. 27 EABs in aortoiliac reconstruction were done including 22 femorofemoral bypass(FFB), 4 axillobifemoral bypass(AxBF). In the latter, EABs were used in older patients with medical comorbidities and contraindication to direct reconstructive procedures involving the abdominal aorta including aneurysms, graft infection, and trauma. One and five-year primary patency rates for entire EABs and FFB were 76.9%, 63.8% and 83.1%, 63.5%, respectively. In FFB, patients with limb- threatening ischemia proved to be inferior to those with claudication as measured by primary patency(p=0.013). Age(>65yr.), sex, smoking, medical comorbidities, duration of symtoms, preoperative angioplasty, use of externally supported graft did not influence primary patency in FFB. The 5-year patient survival rates for entire EABs and FFB were 70.4%, 67.9%. Limb salvage rates for entire EABs and FFB were 65.1%, 66.7% at 3 years. Our results suggest that strict selection of patients with limb-threatening ischemia and medical comorbidities may contribute inferior patency rate of EABs. To determine the application of EABs in aortoiliac reconstruction, the nature of intraabdominal pathology and operative risk with vascular surgeon's experience and judgement should be considered.
Aneurysm ; Angioplasty ; Aorta, Abdominal ; Comorbidity ; Humans ; Ischemia ; Limb Salvage ; Pathology ; Retrospective Studies ; Smoke ; Smoking ; Survival Rate ; Transplants

Endovascular aneurysm repair (EVAR) was initially introduced as a less invasive alternative to conventional open repair. EVAR was subsequently adopted as a treatment option for abdominal aortic aneurysm. In Korea, open repair is more widely available than EVAR, although EVAR can be performed in several hospitals. Due to the rapidly aging population in Korea, there has been a shift from private healthcare to government-regulated universal coverage and EVAR may be a more feasible option for cardiovascular interventionalists in these days. The improvement of EVAR was rapidly attained by many pioneers for the last two decades. Although issues such as indications and durability of EVAR remain to be elucidated, its application can be extended further of milder invasiveness-related effects on comorbidities and less discomfort to patients. Aortic stent-grafting has been performed for various aortoiliac pathologies over the last 13 years at our cardiovascular center.1-3) This article presents a comprehensive review on EVAR by focusing on the clinical trials, indications, complications, and expertise in decision making for EVAR.
Aging ; Aneurysm ; Aorta, Abdominal ; Aortic Aneurysm ; Aortic Aneurysm, Abdominal* ; Comorbidity ; Decision Making ; Delivery of Health Care ; Humans ; Korea ; Pathology ; Stents ; Universal Coverage