Dissecting aortic aneurysm as a complication of generalized fibromuscular dysplasia.

This is the first report of a dissecting aneurysm of the aorta caused by generalized vascular fibromuscular dysplasia. An 18-year-old black man suddenly developed paraparesis and bilateral pulse loss below the waist. An aortogram disclosed a dissecting aneurysm of the entire aorta and an obstruction of blood flow below the renal arteries. On postmortem examination, the dissection of the aorta was found to be due to fibromuscular dysplasia that affected not only the aorta, but multiple other arteries as well.     

Gastrointestinal arterial fibromuscular dysplasia of childhood

An unusual case of a progressive, noninflammatory stenosing vasculopathy, arterial fibromuscular dysplasia is presented. The distinctive features of this particular case include onset in early childhood with a predominant involvement of the gastrointestinal system, sparing of the renal arteries, lack of hypertension, and no cutaneous features of progressive systemic sclerosis. We discuss the clinical history over a decade and the pathologic features, including routine and electron microscopic findings of biopsy and autopsy tissues, and review the literature.     

The occurrence of fibromuscular dysplasia in the arteries of domestic turkeys.

Fibromuscular dysplasia (FMD) was found in 24 of 31 turkeys studied. This is the first species other than man in which FMD has been reported. FMD in turkeys simulates lesions variously known as fibromuscular dysplasia, fibromuscular hyperplasia, and medial hyperplasia in man. It occurred in turkeys from 8 weeks to 1 year of age and was evenly distributed between the sexes (11 males, 13 females). FMD in turkeys is a disease of arterioles and small arteries 44 mu to 666 mu in diameter. A lesion of more than 2.6 mm in length (in an artery 0.1 mm in diameter) was encountered. An adherent thrombus over 670 mu long was seen attached to an FMD lesion. Angiopathy appears to be basic to the pathogenesis of FMD and is characterized by endothelial hyperplasia, smooth-muscle vacuolization, and patchy necrosis of the media.     

Isolated fibromuscular dysplasia of the coronary arteries with spontaneous dissection and myocardial infarction

Fibromuscular dysplasia (FMD) is a segmental, nonatherosclerotic vascular disease of unknown etiology. Both the renal and extrarenal arterial FMD may have focally deficient or absent muscular media, and spontaneous dissection is a serious complication of this arterial wall abnormality. Although FMD may be found in virtually any small and medium-sized arteries, to our knowledge, FMD of the coronary arteries previously has not been documented convincingly in the literature. This article describes one such unusual occurrence of FMD in the coronary arteries with spontaneous dissection and myocardial infarction.     

A case of sudden death caused by fibromuscular dysplasia

After sudden unexpected death in a previously healthy 42 year old woman, necropsy examination showed myocardial infarction caused by occlusion of a vital coronary artery by fibromuscular dysplasia. This is a rare arterial disease with a clinical onset usually in the third or fourth decades of life. The aetiology is not fully understood but since it affects vital (cerebral and coronary) blood vessels it often has fatal consequences.     

Marfan syndrome with aortic dissection and triple-barrel aorta.

A case of Marfan syndrome with spontaneously and subsequently developed dissections of the aorta, one in the form of triple-barrel aorta, three times corrected by grafts is described. The autopsy revealed "healed" and acute dissections in almost the entire aorta outside the grafts. "Healed" thoracoabdominal dissection had true lumen (with entry and re-entry intimal tears), and old false lumen and in addition in its distal portion of a triple-barrel aorta was formed (dissection of healed aortic dissection). Lethal adventitial rupture occurred in the portion with an old false lumen. Dissection of the left subclavian artery, the right common carotid artery, resulting in saccular aneurysm, and avulsion of the right renal artery were also found.     

Sudden cardiac death due to fibromuscular dysplasia of the coronary arteries

A man to whom sudden cardiac death occurred after he had lived to the age of 25 years in perfect condition is reported in this paper. Fibromuscular dysplasia of the coronary arteries was established as the cause of death by postmortem examination.     

Age-related fibromuscular dysplasia in the human left ventricle papillary muscles arteries

We describe histologically cases of patients between 31 and 60 years of age who had fibromuscular dysplasia (FMD) in the tunica media (TM) of the left ventricle papillary muscles (PM) arteries. We also compared them with our previous findings in subjects younger than 30 years of age. We examined histologically samples taken from the tip of the anterior PM of the left ventricle in 200 healthy male hearts. In 33 cases (16.5 %), FMD was in the TM. We divided these cases into three subgroups (A, B, C) based on the degree of replacement of smooth muscle cells by fibrous tissue, and thus identified 17, 11 and 5 cases, respectively. Until the age of 41, the typical lesions were often localized within the TM. Beyond that age, the fibrous tissue increased in the TM wall and in the surrounding area of the vessels, causing dysfunction of the PM. Degenerative lesions, as well as inflammatory infiltration, were found after the age of 53. The findings of this study will be useful to cardiologists and cardiac surgeons, in pointing out that, after the age of 44 years old, some PM and their supporting valves may present a degree of dysfunction.     

Hypoplasia of left vertebral artery with intimal fibromuscular dysplasia in a Korean woman

We found a case of hypoplasia of vertebral artery with fibromuscular dysplasia in an 82-yr-old Korean female cadaver during a routine dissection course. In the present case, intracranial hypoplasia in left vertebral artery and bilateral origin of posterior inferior cerebellar artery at the vertebrobasilar junction were recognized. Histopathologically, left vertebral artery showed intimal type of fibromuscular dysplasia both in its extracranial and intracranial courses. These results indicate that the association of fibromuscular dysplasia and hypoplasia does exist in the vertebral artery, although the etiologies are not verified yet.     

Unusual lamellar calcifications in two rare cases of splenic aneurysms associated with fibromuscular dysplasia

Fibromuscular dysplasia (FMD) of the splenic artery is a rare underdiagnosed condition. Here, we report two cases of FMD affecting the splenic artery: one alone and one concomitantly with the renal artery. Histology revealed fibromuscular thickening of the media layer alternating with a circumferential calcification of the whole artery thickness. Ultrastructurally, FMD showed matrix vesicles and dense bodies in the extracellular matrix. A diagnosis of FMD with calcification was made. This is the first report to document circumferential lamellar calcifications alternating with the more typical fibrotic medial areas in the rare FMD localized to splenic artery.     

Endothelial adaptations in aortic stenosis. Correlation with flow parameters.

A 69 +/- 5% stenosis was produced in the rat aorta, with the purpose of correlating endothelial changes with local flow patterns and with levels of shear stress; the hydrodynamic data were obtained from a scaled-up model of the stenosed aorta. In the throat of the stenosis, where shear stress values were 15-25 times normal, the endothelium was stripped off within 1 hour. It regenerated at half the rate of controls but modulated into a cell type that could withstand the increased shear stress. Adaptations included changes in cell orientation, number, length, width, thickness, stress fibers, and anchoring structures, as well as changes in the length, argyrophilia, and permeability of the junctions. Areas of either elongated or "polygonal" cells consistently developed at the same sites in relation to the stenosis, but the hydrodynamic data showed that they did not always correspond (as had been anticipated) to high and low shear, respectively. It is concluded that endothelial cell shape in the living artery must be determined by some other factor(s) in addition to shear stress.     

Morphogenesis of fibromuscular dysplasia of the renal arteries (an ultrastructural study)]

Ultrastructural examinations of 32 cases of various forms of fibrousmuscular dysplasia (FMD) of renal arteries showed the lesions at the subcellular level to be identical in all these forms and to differ only in their intensity and localization. As the disease progresses, smooth muscle cells (SMC) show signs of activation accompanied by an increased collagen synthesis. In this, the cells exhibit large multiblade nuclei, intensive proliferation of the granular endoplasmic reticulum, hypertrophy of the Golgi complex. In cases of intensive fibrous changes, occasional fibroblasts appear in the arterial media. As collagen accumulates in intercellular spaces, signs of involution of various degrees are found in SMC. The number of elastic fibers in the media of the affected arteries decreases markedly as compared with the control. The inner elastic membrane of the arteries is frequently destroyed, particularly in the intimal form of the lesions. The study suggests that all forms of FMD represent a single process in the morphogenesis of which the leading role is played by fibroblast-like transformation of SMC.     

Medullary sponge kidney associated with multivessel fibromuscular dysplasia: report of a case with renovascular hypertension

Medullary sponge kidney (MSK) is a congenital anomaly characterized by dilatation of the collecting ducts of Bellini associated with defective urinary acidification and concentration. Medullary nephrocalcinosis/ nephrolithiasis is the usual presentation in adults, however neonatal and childhood cases are being reported with increasing frequency. Among the conditions associated with MSK are Beckwith-Wiedemann syndrome/hemihyperplasia (13%), horseshoe kidney, congenital small kidney, hyperparathyroidism, Caroli syndrome, congenital hepatic fibrosis, Ehlers-Danlos syndrome, Marfan syndrome, immotile cilia syndrome, and arterial fibromuscular dysplasia. This article describes an adult female who underwent nephrectomy for renovascular hypertension due to multivessel fibromuscular dysplasia with small left kidney found to be associated with MSK.     

Concurrence of supravalvular aortic stenosis and peripheral pulmonary stenosis in three generations of a family: A form of arterial dysplasia

Isolated supravalvular aortic stenosis (SVAS) commonly is an autosomal dominant trait; it may also occur in the Williams syndrome (WS). While peripheral pulmonary stenosis (PPS) can occur in the same individual with familial isolated SVAS, concurrence of these lesions in different relatives of a family is uncommon. We describe five affected individuals in one family; three had isolated SVAS, one had isolated PPS, and one had SVAS and PPS. Based on this family and review of literature, we suggest that SVAS is a form of arterial dysplasia encompassing PPS in its spectrum. It is developmentally distinct from other left heart obstructive lesions that are hypothesized to be related to blood flow abnormalities in the developing embryo. We also conclude that the clinical disorder in this family represents one that is distinct from WS. © 1993 Wiley-Liss, Inc.