Influence of serum cholesterol on atherogenesis and intimal hyperplasia after angioplasty: inhibition by amlodipine.

The objectives of the present study were to determine whether serum hypercholesterolemia (HC) promotes the development of spontaneous and angioplasty-induced lesions and whether amlodipine inhibits these lesions and cellular processes underlying their genesis. Rabbits were fed normal, 0.5%, or 2% cholesterol diets for 9 wk, which resulted in the development of increasing HC. After week one, balloon dilation of the abdominal aorta was performed while the thoracic aorta was not disturbed and monitored for the development of spontaneous lesions. Lesion size increased with the degree of HC and was accompanied by increased collagen synthesis and smooth muscle cell (SMC) proliferation at each site. Amlodipine (5 mg/kg p.o.) inhibited lesion size by 50% (P < 0.01) at both sites in cholesterol-fed animals but not at angioplasty sites in animals on a normal diet. Local collagen synthesis was inhibited at both sites by amlodipine in the diet animals. The increase in HC was accompanied by a 1.7-fold increase in basal Ca2+ uptake in SMCs in the thoracic aorta, which was not altered by amlodipine, nifedipine, Ni2+, or La3+, revealing an uninhibitable calcium leak during atherogenesis. In culture, cholesterol enrichment increased SMC proliferation, collagen synthesis, and the secretion of a soluble SMC mitogen, which were inhibited by amlodipine (10(-9) M). Finally, in SMC membranes, amlodipine uniquely restored the cholesterol-expanded membrane bilayer width without any effect on membrane fluidity. This study establishes a causal role between serum HC and the development of spontaneous and angioplasty-induced lesions and the ability of amlodipine to disrupt this action by a novel remodelling action on the SMC membrane.

Peripheral vascular disease. Diagnosing and treating the 3 most common peripheral vasculopathies.

A common sign of generalized atherosclerosis, peripheral vascular disease (PVD) occurs as a result of arterial narrowing or obstruction that restricts blood flow to distal tissues. Prevalence of PVD ranges from 3% in patients age > 55, to 11% in patients age > 65, to 20% in those age 75 and older. Cerebrovascular/carotid disease, abdominal aortic aneurysms, and peripheral arterial occlusive disease are the most common peripheral vasculopathies seen by primary care physicians. All require aggressive medical management to prevent potentially serious complications and may require referral to vascular surgeons for evaluation. Prevention remains the best therapy.

Application of duplex US for characterization of endoleaks in abdominal aortic stent-grafts: report of five cases.

Endoleaks were detected with helical computed tomographic (CT) angiography in five patients after placement of an aortobiliac stent-graft. The leaks were subsequently evaluated with duplex ultrasonography (US) and, in four patients, with conventional aortography as well. CT angiography revealed a total of seven endoleaks, all of which were prospectively classified as reconstitution (type II) leaks. Duplex US demonstrated six of the seven endoleaks. At duplex US, two of the leaks were characterized as attachment-site (type I) leaks; these two diagnoses were confirmed during subsequent angiography and profoundly altered clinical care. As an adjunct to CT angiography in evaluating endoleaks, duplex US provides hemodynamic information that enables further characterization of the type of endoleak and facilitates appropriate clinical care.

Ischemic jejunal stricture following endovascular abdominal aortic aneurysm repair -- a case report.

Endograft repair has rapidly become an alternative to conventional open repair of abdominal aortic aneurysms. Various trials continue to show decreased morbidity when compared to open repair. However, as with any new procedure, complications specifically related to this technique are being described. Herein, we report a case of an isolated ischemic jejunal stricture presenting as a small-bowel obstruction secondary to cholesterol emboli following endograft repair of an abdominal aortic aneurysms.

Superior mesenteric artery pseudoaneurysm successfully treated with polytetrafluoroethylene covered stent.

A postoperative superior mesenteric artery pseudoaneurysm that communicates with a pancreatic pseudocyst after aortic surgery is a difficult management problem. Untreated, this condition can lead to exsanguination. Traditional surgical treatment has many potential complications. Endovascular repair has the potential for avoidance of surgical complications. We present the first superior mesenteric artery pseudoaneurysm successfully treated with A polytetrafluorethylene covered stent.