Severe Aortic Atherosclerosis Research Articles

Trends in surgical revascularization for renal artery disease. Ten years' experience

We reviewed our experience with surgical revascularization (SR) for renal artery disease (RAD) in 361 patients from 1975 through 1984 to illustrate the evolving role of SR in the management of these patients. The time intervals selected for comparison were 1975 through 1980 (n=174) and 1981 through 1984 (n=187). Since 1981, in patients with atherosclerosis, SR has been done more often in elderly patients (30% vs 10.4%), in patients with generalized atherosclerosis (87% vs 73%), and for the sole purpose of preserving renal function (36% vs 14%). Since 1981, fewer patients with atherosclerosis have undergone SR solely to treat renovascular hypertension (26% vs 41%). Since 1981, in patients with fibrous dysplasia, SR has been done in more patients with branch renal artery disease (70% vs 28%). These trends in the performance of SR have been due to the advent of percutaneous transluminal angioplasty as effective therapy for certain patients, improved results of SR in elderly patients with atherosclerosis, an enhanced appreciation of advanced atherosclerotic RAD as a correctable cause of renal failure, and the development of more effective techniques for SR in patients with severe aortic atherosclerosis and branch RAD. The overall clinical results of SR remain excellent in properly selected patients with RAD. (<i>JAMA</i>1987;257:498-501)

Trends in Surgical Revascularization for Renal Artery Disease

We reviewed our experience with surgical revascularization (SR) for renal artery disease (RAD) in 361 patients from 1975 through 1984 to illustrate the evolving role of SR in the management of these patients. The time intervals selected for comparison were 1975 through 1980 (n = 174) and 1981 through 1984 (n = 187). Since 1981, in patients with atherosclerosis, SR has been done more often in elderly patients (30% vs 10.4%), in patients with generalized atherosclerosis (87% vs 73%), and for the sole purpose of preserving renal function (36% vs 14%). Since 1981, fewer patients with atherosclerosis have undergone SR solely to treat renovascular hypertension (26% vs 41%). Since 1981, in patients with fibrous dysplasia, SR has been done in more patients with branch renal artery disease (70% vs 28%). These trends in the performance of SR have been due to the advent of percutaneous transluminal angioplasty as effective therapy for certain patients, improved results of SR in elderly patients with atherosclerosis, an enhanced appreciation of advanced atherosclerotic RAD as a correctable cause of renal failure, and the development of more effective techniques for SR in patients with severe aortic atherosclerosis and branch RAD. The overall clinical results of SR remain excellent in properly selected patients with RAD.

Renal Revascularization by End-To-End Anastomosis of the Hepatic and Renal Arteries

From June 1981 to January 1984, 13 patients with atherosderotic renal artery disease underwent revascularization by end-to-end anastomosis of the hepatic and renal arteries. Renal revascularization was indicated to preserve renal function and/or to treat associated hypertension. An aortorenal bypass was not possible owing to severe aortic atherosclerosis or a prior aortic operation. Right renal revascularization was performed by end-to-end anastomosis of the renal artery to the common hepatic artery in 7 patients, right hepatic artery in 4, left hepatic artery in 1 or gastroduodenal artery in 1.Postoperatively, 2 patients suffered a necrotic gallbladder owing to ischemia and 1 of these patients died. Liver enzymes were elevated immediately postoperatively in 11 patients but returned to normal within 2 weeks in each case. Currently, all 12 surviving patients have normal liver function, well controlled blood pressure and improved renal function. End-to-end anastomosis of the hepatic and renal arteries is an effective method of revascularization but specific measures must be taken to avoid complications of gallbladder ischemia.

Reconstructive surgery for multiple renal arteries

Renal artery occlusions occur in patients with severe aortic atherosclerosis, panarteritis, as well as as a result of previous operations and are severe vascular pathology. It is very difficult to restore renal blood circulation in such patients, since this often affects the areas of bifurcation or trifurcation of the renal arteries. Cases of multiple renal arteries are especially difficult. It is known that surgical treatment for occlusions consists in creating bypass anastomoses, in particular the anastomosis of the superior mesenteric artery with the renal artery using the great saphenous vein [5]. However, the formation of this anastomosis is feasible only when treating a single renal artery, while its multiplicity is observed in 1538% of cases [13].

"Spontaneous" atheroembolic disease as a cause of renal failure in the elderly.

An 86-year-old man with previous normal renal function was hospitalized because of renal insufficiency. He had a long history of atherosclerotic heart disease, mild hypertension and pulmonary embolism, requiring anticoagulant therapy. In view of the normal-sized kidneys and absence of casts in the urinary sediment, a diagnosis of atheroembolic renal disease was made. The patient's renal function deteriorated, but he refused hemodialysis. Death occurred within a few weeks. At autopsy, severe aortic atherosclerosis was observed and atheroembolic renal disease was confirmed as the cause of renal failure. Occasionally, renal failure can be the sole manifestation of spontaneous atheroembolic disease. This possibility should be considered if the physician is called upon to establish the diagnosis when renal insufficiency develops in atherosclerotic patients.

Aortic Dissection Complicating Aortocoronary Saphenous Vein Bypass

A high autopsy incidence, 7 of 50 cases (14%), of aortic dissection as the major cause of death in patients who died following aortocoronary saphenous vein bypass is reported. The patients ranged in age from 45 to 61 years, and all had moderately severe aortic atherosclerosis. None was hypertensive, and no significant predisposing aortic medial disease was recognized. Trauma during surgical cannulation with retrograde perfusion through atherosclerotic femoral or iliac arteries was considered the initiating event leading to ileo-aortic dissection in five of the seven patients. Damage secondary to aortic cross-clamping is suggested as the pathogenetic mechanism leading to dissection in the other two patients. In six patients, the dissection was Type I of DeBakey, and in one patient, Type II. Dissection was recognized intra-operatively in five of the seven patients. In older patients, particularly those likely to have atherosclerosis of the aorta and its main branches, vigilance regarding the possibility of aortic dissection developing during the course of cardiopulmonary bypass must be constant.

Plasma and aortic lipids in experimental canine atherosclerosis

Twenty-four dogs were split into three equal groups for an experimental period of 1 year. Group A was fed a semisynthetic diet containing 5% cholesterol and 16% hydrogenated coconut oil (HCO). Another eight dogs were fed diet B which differed from diet A only in that one-quarter of the HCO was replaced by safflower oil. Group C ate a controlled diet of meat and kibble. Diet A contained no essential fatty acids while diets B and C contained sufficient amounts of linoleic acid to satisfy established nutritional requirements. Severe aortic, coronary, and cerebral atherosclerosis was present at autopsy in group A dogs but no lesions were observed in any of the dogs fed diets B and C. All dogs of group A had profound elevations in plasma lipid concentrations when compared with dogs of control group C. Dogs of group B had more moderate increases. The largest elevation occurred in the cholesteryl esters of group A. The predominant ester in the plasma of group A dogs was cholesteryl oleate. In contrast, the major plasma cholesteryl ester in dogs of groups B and C was linoleate. Intima-media samples from atherosclerotic aortic segments showed large increases in lipid concentrations. The bulk of the increases was due to the accumulation of cholesteryl esters and the major cholesteryl ester within the lesion was oleate. The predominant cholesteryl ester in the normal intima-media of groups B and C was cholesteryl linoleate. Fatty acid analyses suggested that much of the lesion cholesteryl ester could have been derived directly from plasma, but the preferential accumulation of cholesteryl oleate and eicosatrienoate suggested that there was also considerable local cholesteryl ester synthesis. Phospholipid eicosatrienoate:arachidonate ratios in excess of 0.4, indicative of essential fatty acid deficiency, were found consistently in the plasma and aortic tissue of group A dogs but not in dogs of group B or C. Essential fatty acid deficiency appeared to be most severe within atherosclerotic intimal plaques.

Reversal of advanced atherosclerosis in Rhesus monkeys: Part 1. Light-microscopic studies

The regression of atherosclerotic lesions in Rhesus monkeys was evaluated by means of a low-fat, low-cholesterol diet with or without N-γ-phenylpropyl-N-benzyloxy acetamide (W-1372). Moderate to severe aortic and coronary atherosclerosis was induced by feeding 4 groups of male monkeys a high-fat, high-cholesterol diet for 18 months, after which the first group was autopsied for assessment of the lesions. During a subsequent 18-month regression period, the second group of animals was fed a low-fat, low-cholesterol diet with W-1372, and the third group the low-fat, low-cholesterol diet without W-1372. A pair of monkeys (the fourth “group”) was fed an atherogenic diet throughout the experiment. Serum cholesterol, which increased about 5-fold during the induction period, returned to baseline values or below in the 2 treated groups. Evidence of regression of lesions was obtained in both these groups, but was most noticeable in the monkeys fed the low-fat, low-cholesterol diet without W-1372. The aortas of the animals treated with the low-fat, low-cholesterol diet with or without W-1372 showed about two-thirds as many lesions which were on the average about half as severe as those in the animals killed at 18 months. The coronary artery lesions showed a similar contrast, with the treated groups having about one-third to one-half as many lesions which were about one-half to two-thirds as severe. In both locations the differences in frequency and severity of arterial lesions were statistically significant when the reference group killed at 18 months was compared with the group treated with the low-fat, low-cholesterol diet without W-1372.

The development of pigeon strains with selected atherosclerosis characteristics

Parental pairs of White Carneau, Show Racer, and F 2 (progeny of F 1 crosses between White Carneau and Show Racer) pigeons were identified according to specific features of the atherosclerosis of their offspring. Progeny were evaluated for atherosclerotic variables after being fed a diet containing 0.5% cholesterol for 6 mo. No significant differences were seen in the degree of hypercholesterolemia between breeds; however, within breeds all males had significantly higher serum cholesterol concentrations than females. Aortic atherosclerosis was more severe in White Carneau than in Show Racer or F 2 with F 2 pigeons being intermediate in the response. All autopsied progeny dying during the experiment showed more aortic and coronary atherosclerosis than their surviving sibs. Likewise, there was more coronary and aortic atherosclerosis in pigeons with myocardial infarcts found when they were killed at the end of the experiment. Aortic root and coronary artery atherosclerosis were assessed as important causative factors in myocardial infarction. Based on the atherosclerotic characteristics of progeny, the following strains have been selected. 1. 1. A strain of White Carneau with severe aortic atherosclerosis having mean aortic cholesterol concentrations of 60.42 mg/g aorta. 2. 2. A strain of Show Racer with very little aortic atherosclerosis having a mean aortic cholesterol concentration of 2.40 mg/g aorta. 3. 3. A strain of F 2 with concomitant severe coronary artery atherosclerosis (mean coronary artery index of 38) and very little aortic atherosclerosis (mean aortic cholesterol concentration of 6.13 mg/g aorta). 4. 4. A Show Racer and an F 2 strain with a frequency of myocardial infarction of 43 and 60%, respectively.

The Influence of Dietary Vitamin A on Atherogenesis in Japanese Quail ,

Two experiments were conducted to study the influence of vitamin A on atherosclerosis. In one experiment quail chicks (Coturnix coturnix japonica) were hatched and immediately placed on diets deficient in vitamin A (880 U.S.P. units/kg. of feed), normal in vitamin A (4,400 U.S.P. units/kg. of feed) or excessive in vitamin A (22,000 and 220,000 U.S.P. units/kg. of feed). In a second experiment, mature male quail were placed on the same diets as in the preceding experiment. All experiments were conducted for 10 weeks. At the end of 10 weeks on experimental rations, blood pressure was measured by cannulation of the carotid artery. The results indicate that birds fed low levels of vitamin A had the highest incidence of coronary atherosclerosis and most severe aortic atherosclerosis. It was determined that a minimum of approximately 15,000 U.S.P. units of the vitamin were needed to minimize atherosclerosis in the thoracic aorta in growing quail chicks.Blood pressure was not significantly altered by varying vitamin A in the diet.

A correlative study between the radiologic and pathologic diagnoses of atherosclerosis of the aorta

1. 1. The pathologic and radiologic findings of atherosclerosis of the aorta have been compared in 190 subjects who were over the age of 30 years. 2. 2. The reliability of the radiologic signs of atherosclerosis has been discussed and attention drawn to the positive diagnostic value of elongation and calcification, and the unreliability of dilatation of the thoracic aorta. The presence of calcification alone does not indicate the presence of severe aortic atherosclerosis. 3. 3. Routine posteroanterior chest films constitute a useful and easily applicable procedure in the detection of aortic atherosclerosis.

Aortic and coronary atherosclerosis in the three racial groups in Cape Town.

An autopsy survey of aortic and coronary atherosclerosis in patients dying in a general hospital in Cape Town has shown marked differences between the whites and the Bantu. These differences were clearly demonstrated by a direct comparison of Bantu and White men between the ages of 40 and 59. They probably also existed among older subjects and women although relatively few Bantu over the age of 60, and fewer women than men were unfortunately available for study. Severe aortic and coronary atherosclerosis did on occasions occur in the Bantu but were much less common than in the whites. Severe luminal narrowing of the coronary arteries was particularly rare in the Bantu, and this is in keeping with the rarity with which they develop myocardial infarction. The aorta and coronary arteries of the Bantu often showed complete freedom from atherosclerosis in age groups in which it was rare to find such freedom in the whites. The differences between the whites and Cape Coloured were much less pronounced than those between the whites and Bantu, were rather more apparent in men than women, and tended to disappear in the presence of aggravating factors such as hypertension. Even in groups in which severe coronary atherosclerosis was as commonly encountered in the Cape Coloured as in the whites, the Cape Coloured appeared to show a lower frequency of severe luminal narrowing. Attention has been drawn to the possibility that the differences between the total white and Cape Coloured populatios of Cape Town are greater than those revealed by this study, as only the lesser economically privileged of the whites were eligible for admission to the hospital that provided the material for the study.

Effect of neomycin on cholesterol atherosclerosis in the rabbit.

SummaryProlonged oral administration of neomycin resulted in a greater elevation of serum lipids and more severe aortic atherosclerosis and visceral lipoidosis in cholesterolfed rabbits than in untreated cholesterol-fed controls. Failure to observe these enhancing effects following intramuscular administration of neomycin indicates that this action is related to increased absorption of cholesterol. Neomycin was without effect on endogenous cholesterol metabolism in this species.