Eugene F. Poutasse

A pathologic-arteriographic correlation of renal arterial disease

Abstract A study of the microscopic features of occlusive renal arterial lesions in 97 patients has shown the advantage of classifying these diseases according to their primary locations in the arterial wall and the types of tissue they comprise. Two lesions were primarily intimal, atherosclerosis and intimal fibroplasia, and three were predominantly medial, medial fibroplasia, fibromuscular hyperplasia, and subadventitial fibroplasia. This classification permitted a close correlation with renal arteriographic features. Atherosclerotic lesions were either circumferential or eccentric plaques, sometimes complicated by thrombosis or dissecting aneurysm. They occurred predominantly in men. Arteriograms showed stenosis of the orifice, with poststenotic dilatation; the presence of thrombosis or dissecting aneurysm was usually indicated by complete obliteration. Intimal fibroplasia was characterized by fibrous intimal hyperplasia associated, at times, with disruption of the internal elastic membrane. Arteriographic features depended on the condition of this membrane; when it was disrupted, an aneurysm formed, producing an irregularly dilated artery. Medial fibroplasia with aneurysms produced the “string-of-beads” arteriogram previously attributed to fibromuscular hyperplasia. The “beads” were aneurysms that developed because segments of the arterial wall were absent, permitting focal dilatations. These thin segments alternated with areas in which the media had been largely replaced by collagen. Muscular hyperplasia was not present. Fibromuscular hyperplasia was an uncommon lesion resulting from increased amounts of fibrous and muscular tissue; it was sometimes accompanied by disruption of the internal elastic membrane. Arteriograms showed either symmetrical stenosis or, when the internal elastic membrane was disrupted, an irregularly dilated artery. We could find no arteriographic features that would differentiate this lesion from intimal fibroplasia. Subadventitial fibroplasia was characterized by dense collagenous thickening of the outer media irregularly replacing the muscular layer; it affected long segments of the renal artery. The arteriographic appearance was that of a severely stenosing lesion with regions of intense stenosis alternating with regions of lesser narrowing. This lesion has also been called “fibromuscular hyperplasia” because the variably severe stenosis produces an irregular arterial outline that suggests “beading.” This study shows subadventitial fibroplasia to be distinct from fibromuscular hyperplasia, as well as from medial fibroplasia, which produces the “string-of-beads” arteriogram.

MECHANISMS, DIAGNOSIS AND TREATMENT OF HYPERTENSION OF RENAL VASCULAR ORIGIN

Excerpt With Richard Brights clinical observations, kidney disease and hypertension became indissolubly, though obscurely, associated; this association seemed to become more tangible when Goldblat...

Occlusion of a Renal Artery as a Cause of Hypertension

This paper presents three cases and the summary of a fourth case, in which occlusion of a renal artery was the cause of hypertension. Three patients were relieved of hypertension by nephrectomy. The literature on nonembolic renal artery occlusion with hypertension is reviewed, including 21 autopsy reports and 16 cases in which the patients were relieved of hypertension by nephrectomy or thromboendarterectomy. When a patient is found to have renal hypertension, the possibility of renal artery occlusion should be considered. Translumbar aortography currently is the best means of demonstrating renal artery occlusion.

An Evaluation of Treatment of Hypertension Associated with Occlusive Renal Arterial Disease

Of 131 patients with hypertension and renal arterial stenosis, 99 were treated either by nephrectomy or revascularization operations and 32 were treated medically. Anti-hypertensive effects of surgical treatment were analyzed in 76 patients in whom operations had been performed 1 to 6 years before. Of the remaining 23, 10 died in the immediate postoperative period; in 11, operative treatment was incomplete at the time of review; and, in 2, who did not have sustained diastolic hypertension, operation was performed only to conserve renal function.Diastolic hypertension remitted in 47 patients (62 per cent); in 12 (16 per cent) arterial pressure was much reduced but not to normal levels, and in 17 (22 per cent) it was unchanged.The antihypertensive effects of surgical treatment could not be predicted preoperatively. In general, patients less than 21 years of age did not respond with as much blood pressure reduction as did those older, and patients hypertensive for longer than 5 years responded less well than those hypertensive for less than 1 year. Results of function tests of individual kidneys were not helpful in prediction.Surgical treatment seemed contraindicated in 32 patients because of diffuse atherosclerosis, azotemia from severe nephrosclerosis, unsustained diastolic hypertension or because lesions had not caused disparity in function of the two kidneys. In three of these patients diastolic hypertension remitted spontaneously and in 11 arterial pressure was controlled at near normal levels with antihypertensive drugs. Eighteen patients have persistent diastolic hypertension; 13 of these have been inadequately treated with drugs.In the group treated surgically, there were 10 immediate postoperative deaths, seven of which were due to atherosclerotic complications. Twelve patients died later, and 11 deaths were due to atherosclerosis. Most of the patients who died had no blood pressure reduction following operation. Ten of the medically treated group have died of atherosclerosis. The mortality was 50 per cent in the patients with ineffective treatment and poor blood pressure control and only 7 per cent in those with good blood pressure control.

Separated renal functions in patients with renal arterial disease, pyelonephritis, and essential hypertension.

Function tests of the individual kidneys have been performed during mannitol diuresis and vasopressin infusion in hypertensive patients with essential hypertension, pyelonephritis, and occlusive lesions of one or both main renal arteries or their primary branches. In patients with essential hypertension, glomerular filtration rate and renal plasma flow on the two sides, though depressed, were practically equal, as were urine flow, water, solute, and sodium excretions. Pyelonephritis and branch arterial lesions alike depressed urine flow, glomerular filtration rate, and renal plasma flow in the affected or more-affected kidneys; water, total solute, and sodium excretions were in proportion to glomerular filtration rate. These findings indicate a decrease in numbers of functioning nephrons without a qualitative change in function of those remaining. Occlusive lesion of one main renal artery decreased glomerular filtration rate and renal plasma flow on the affected side; urine flow was relatively more depressed than filtration rate, urinary osmolality was higher, and urinary sodium concentration was sharply decreased, as was the excreted fraction of the filtered sodium load. Bilateral occlusive main arterial lesions sometimes had effects similar to those of unilateral lesions in the sense of greater functional deficits on the more-affected sides. However their functional patterns were not consistent. The enhanced renal sodium reabsorption observed in patients with unilateral and bilateral main renal artery diseases could not be explained solely by decreases in filtered sodium load; this suggests that decreases in intrarenal arterial pressure also affect sodium excretion. Changes in renal functions caused by arterial disease depend on the site of the lesion and not on the pressor mechanism it may evoke.

Effect of Bilateral Nephrectomy and Kidney Transplantation on Hypertension in Man

In conclusion, we consider that renal hypertension may have two components: a renal component and a renoprival component (fig. 6). Bilateral nephrectomy abolishes the renal component and leaves a renoprival hypertension that is sensitive to water and salt. Implantation of a kidney may cure the renoprival hypertension. Rejection of the graft may then be followed by a return of renal hypertension. Since the technique of transplantation of kidneys taken from cadavers is improving steadily, repeated nephrectomies and a second transplant become possible.

THE COURSE OF RENAL HYPERTENSION AFTER BILATERAL NEPHRECTOMY AND TRANSPLANTATION

A brilliant young college mathematics student knew that he had had renal disease for many years, but finally he became severely uremic and hypertensive. When life without dialysis was no longer possible, he was treated with the artificial kidney one or two times per week. Now he is in his third year of hemodialysis. During each dialysis his weight was reduced by ultrafiltration with the artificial kidney, and usually the arterial blood pressure, systolic and diastolic, would fall. However, during the following days, when he reaccumulated both salt and water, it would again rise. During the course of many months, there was a gradual reduction in his basic weight. Although he lost considerable body mass, he also was gradually dehydrated, and concommitant with this, the average level of blood pressure fell. When he socialized with friends and disregarded his 500 mg. sodium diet slightly, his blood pressure would rise. During his second year of dialysis, he adapted himself better to the situation. Patients in severe renal failure can be classified in two categories: the one group comprises those in whom it is fairly easy to reduce the blood pressure when they follow a 500 mg. sodium diet and when they are carefully dehydrated with the artificial kidney; and the other group in whom it is virtually impossible to do so. By dehydration and salt restriction they come into a state that alternates between hypertension and orthostatic hypotension. After many weeks or months of invalidism, they finally reach a stage in which it becomes possible to manage the blood pressure easier, but it is a time-consuming and, therefore an expensive and often trying period. For example, one 33-year-old man had malignant hypertension with papilledema and terminal uremia. Notwithstanding multiple dialyses during a three-month period, which kept the uremia under control, his blood pressure remained a problem. He was repeatedly in cardiac failure. His eyeground changes improved little. He lost muscle mass, and he also began to lose courage. It was decided to remove both kidneys. After bilateral nephrectomy it was far easier to manage the blood pressure. The improvement in his general condition was obvious. Most remarkable was the change in the color of the skin, which appeared to be slightly flushed, as compared with the livid pale color of malignant hypertension that we all know. When he was in the hospital, his blood pressure could be maintained easily within nearly normal limits by restriction of water and salt intake. When he went home and overindulged in salt and water, his blood pressure would rise, sometimes as high as it had been before, but it was easy to control by salt and water restriction. This patient was observed periodically for one year postnephrectomy, during which time two attempts at transplantation failed, and at the end of this period he was still normotensive and his eyeground lesions had healed. In regard to the two categories of patients mentioned earlier, after bilateral nephrectomy, the group with the difficult hypertension becomes much easier to treat. In the other group, bilateral nephrectomy does not seem to alter the condition in regard to the treatment of hypertension. It seems as though they were already in the renoprival state before nephrectomy. The condition that causes the

Pheochromocytoma: Diagnosis and treatment

Summary Pheochromocytoma is a rare disease, but since it is curable, every patient who has any of its characteristic signs and symptoms should be examined care-fully. The diagnosis is established in the majority of patients today by the demonstration of excessive amounts of catecholamines in the blood or urine, or of metabolites of catecholamines in the urine. The pharmacologic tests confirm the diagnosis. The tumors are usually benign, but some show microscopic evidence of malignancy and a few may show evidence of local extension to the regional lymph nodes or blood vessels. Some pheochromocytomas located in the adrenal gland are large enough to be visualized by ordinary radiographic procedures; others are small or in extra-adrenal locations and may be difficult to locate radiographically. Aortography may be used successfully to visualize the tumor provided the blood pressure is monitored. It is not necessary, however, to visualize the tumor once the diagnosis has been established chemically. Exploration of both adrenal glands and the entire retroperitoneal space down to the bladder is necessary in all cases because the tumors may be multiple. Surgical removal of pheochromocytoma should have no mortality when the internist, the anesthesiologist and the surgeon combine their skill and experience.

Renal artery disease and hypertension.

The most important cause of renal hypertension is actually an extrarenal disease, occlusive disease of the renal arteries. Arteriosclerosis is responsible for the majority of these lesions, and stenosing fibroplasia accounts for a smaller group. The renal arterial plaques that are now being recognized in middle-aged hypertensive patients have a grave potential in terms of loss of renal function.

The Course of Renal Hypertension after Bilateral Nephrectomy and Transplantation.

Excerpt In 1962 we lost two patients after transplantation of cadaver kidneys that never functioned. Since April 1, 1963, we have performed seven transplants without losing one patient. One kidney ...