Multifocal Stenosis Research Articles

Cryptogenic, Multifocal, Ulcerous, and Stenosing Enteritis as a Manifestation of Enterocolic Venopathy

Cryptogenic, multifocal, ulcerous and stenosing enteritis (CMUSE) is a poorly understood and exceptionally rare disease typically characterized by the presence of multifocal persistent small bowel ulceration and stenosis (1). Some of the features of CMUSE point to a vascular etiology, although to da

Vessel Wall Contrast Enhancement: A Diagnostic Sign of Cerebral Vasculitis

Purpose: Inflammatory stenoses of cerebral arteries cause stroke in patients with florid vasculitis. However, diagnosis is often difficult even with digital subtraction angiography (DSA) and biopsy. The purpose of this study was to establish the value of contrast-enhanced MRI, proven to be sensitive to extradural arteritis, for the identification of intracranial vessel wall inflammation. Patients and Methods: Twenty-seven patients with a diagnosis of cerebral vasculitis affecting large brain vessels were retrieved from the files: 8 children (2–10 years, 7 female, 1 male) and 19 adults (16–76 years, 10 female, 9 male). Diagnosis was based on histological or serological proof of vasculitis or on clinical and imaging criteria. All MRI examinations included diffusion-weighted imaging, time-of-flight magnetic resonance angiography (TOF-MRA) and contrast-enhanced scans. MRI scans were assessed for the presence of ischemic brain lesions, arterial stenoses, vessel wall thickening and contrast uptake. Results: Ischemic changes of the brain tissue were seen in 24/27 patients and restricted diffusion suggestive of recent ischemia in 17/27; 25/27 patients had uni- or multifocal stenoses of intracranial arteries on TOF-MRA and 5/6 had stenoses on DSA. Vessel wall thickening was identified in 25/27, wall enhancement in 23/27 patients. Conclusion: Wall thickening and intramural contrast uptake are frequent findings in patients with active cerebral vasculitis affecting large brain arteries. Further prospective studies are required to determine the specificity of this finding.

Fibromuscular dysplasia

Fibromuscular dysplasia (FMD), formerly called fibromuscular fibroplasia, is a group of nonatherosclerotic, noninflammatory arterial diseases that most commonly involve the renal and carotid arteries. The prevalence of symptomatic renal artery FMD is about 4/1000 and the prevalence of cervicocranial FMD is probably half that. Histological classification discriminates three main subtypes, intimal, medial and perimedial, which may be associated in a single patient. Angiographic classification includes the multifocal type, with multiple stenoses and the 'string-of-beads' appearance that is related to medial FMD, and tubular and focal types, which are not clearly related to specific histological lesions. Renovascular hypertension is the most common manifestation of renal artery FMD. Multifocal stenoses with the 'string-of-beads' appearance are observed at angiography in more than 80% of cases, mostly in women aged between 30 and 50 years; they generally involve the middle and distal two-thirds of the main renal artery and in some case also renal artery branches. Cervicocranial FMD can be complicated by dissection with headache, Horner's syndrome or stroke, or can be associated with intracerebral aneurysms with a risk of subarachnoid or intracerebral hemorrhage. The etiology of FMD is unknown, although various hormonal and mechanical factors have been suggested. Subclinical lesions are found at arterial sites distant from the stenotic arteries, and this suggests that FMD is a systemic arterial disease. It appears to be familial in 10% of cases. Noninvasive diagnostic tests include, in increasing order of accuracy, ultrasonography, magnetic resonance angiography and computed tomography angiography. The gold standard for diagnosing FMD is catheter angiography, but this invasive procedure is only used for patients in whom it is clinically pertinent to proceed with revascularization during the same procedure. Differential diagnosis include atherosclerotic stenoses and stenoses associated with vascular Ehlers-Danlos and Williams' syndromes, and type 1 neurofibromatosis. Management of cases with renovascular hypertension includes antihypertensive therapy, percutaneous angioplasty of severe stenoses, and reconstructive surgery in cases with complex FMD that extends to segmental arteries. The therapeutic options for securing ruptured intracerebral aneurysms are microvascular neurosurgical clipping and endovascular coiling. Stenosis progression in renal artery FMD is slow and rarely leads to ischemic renal failure.

The Effect of Adventitia Stripping in Refractory Ischemic Digits

Ischemic disease of digits is a very frustrating and extremely difficult clinical problem. It is often caused by a variety of diseases, such as atherosclerosis, connective tissue disease, trauma and Raynaud's disease. Patients with this problem usually suffer from poor tissue perfusion and impaired microcirculation. In clinical, ischemic digits often present with pain, cold intolerance, ulceration and even gangrene change. Many strategies are proposed today to overcome this disease. Behavioral therapies, such as avoidance of cold exposure and smoking are a very important intervention. Pharmacologic therapies, like the administration of calcium channel blocker, PGE1 and other vasodilators have been the most commonly used agents. Sympatholytic drugs have also been added to reduce the sympathetic tone in vascular smooth muscles. In addition, anticoagulants or antiplatelet agents are administered to inhibit thrombus formation in occlusive vascular disease. Although these agents are usually effective, unfortunately, in refractory cases, amputation is unavoidable. Those patients have to suffer the fate of partial or total loss of the digits. This ultimate outcome frequently comes with high morbidity and dysfunctions both in physical and psychological terms. In those cases which are refractory to medical therapy, surgical intervention had been carried out to improve tissue perfusion. Tissue perfusion depends on the integrity of the vasculature and the neurovascular regulatory elements. Historically, microsurgical revascularization and sympathectomy were widely performed to recover adequate blood flow. Microvascular reconstruction with interposition vein grafting can be used to reestablish the vascular structure. However, not all cases with digital ischemia are suitable for this procedure due to the possible occurrence of multifocal stenosis. Sympathectomy can reduce sympathetic tone and thus increase the radius of blood vessel. According to Poiseuille's law, blood flow is directly proportional to the fourth power of the vessel's radius. So even a small increase of radius of blood vessel can lead to a very great increase in blood flow. According to Pick and Flatt, sympathetic fibers travel along the epineurium of peripheral nerve, pass to the adventitia, and innervate the smooth muscle of vessels. The removal of adventitia can block the sympathetic tone in the smooth muscle. This procedure may also increase the radius of vessel and reestablish adequate blood flow.

Early multifocal stenosis after coronary artery snaring during off-pump coronary artery bypass in a patient with diabetes

J Thorac Cardiovasc Surg 2001;122:1044-5

Vertebrobasilar artery territory infarction as an initial manifestation of systemic lupus erythematosus

Cerebral infarction is a well-documented complication of systemic lupus erythematosus (SLE), that usually occurs several years after the diagnosis of SLE. To our knowledge, however, strokes associated with vertebrobasilar artery involvement were not reported to present as an initial manifestation of SLE. We report two patients, who presented with vertebrobasilar territory infarction as an initial manifestation of SLE. Patient 1 was a 16-year-old girl, who developed dysarthria and ataxia. MRI showed multiple infarcts in the pons, cerebellum and thalamus. Four-vessel cerebral angiography showed multifocal stenoses in the vertebral and basilar arteries with beaded appearance. Patient 2 was a 26-year-old woman, who developed headache associated with dysarthria, dizziness and ataxia. MRI showed multiple infarcts in the cerebellum, medulla, pons, midbrain and thalamus. Cerebral angiography revealed occlusion of both vertebral arteries at the first cervical vertebral level with non-visualization of the basilar artery. Both patients were diagnosed as having SLE supported by laboratory results. Although rare, posterior circulation stroke can present as an initial manifestation of SLE, which may be attributed to vasculitis or dissection in the vertebral/basilar artery.

Diagnosis and treatment of pulmonary atresia and ventricular septal defect

Surgical repair of the intracardiac anatomy in patients with pulmonary atresia and ventricular septal defect can be performed today with a low operative mortality. Diagnostic and therapeutic problems in these patients are almost exclusively related to the nature of collateral lung perfusion and associated anomalies of the pulmonary vascular bed. These anomalies are frequently found in patients with major aortopulmonary collateral arteries and include multifocal pulmonary blood supply, hypoplasia, stenosis, or arborization anomalies of the pulmonary arteries. Diagnostic methods must focus on an exact identification of the collateral pulmonary blood supply, the presence and size of central pulmonary arteries, and the connections of the arterial segments. Recent genetic studies have shown that monosomy 22q11.2 is found in 25–32% of children with pulmonary atresia and ventricular septal defect. This microdeletion is significantly more frequent in patients with major aortopulmonary collateral arteries and it seems to be associated with a higher percentage of pulmonary arterial anomalies. During recent years, efforts have concentrated on earlier treatment of patients with pulmonary atresia with ventricular septal defect with combined catheter and surgical interventions. Early establishment of antegrade flow to the central pulmonary arteries stimulates growth of the pulmonary arteries, optimizes the angiographic diagnosis of abnormalities of the pulmonary vascular bed, and allows for the possibility of balloon angioplasty or stenting of the central pulmonary arteries.

Late hemodynamic failure following percutaneous transluminal angioplasty for long and multifocal femorpopliteal stenoses

The outcome of percutaneous transluminal angioplasty (PTA) was evaluated for treatment of 87 limbs with femoropopliteal stenoses, including 55 short stenoses (2.4 +/- 1.6 cm, mean +/- SD), seven single long stenoses (10.4 +/- 2.0 cm), and 25 multifocal stenoses (2.1 +/- 1.6 cm), where two to four separate segments were dilated. Following 98% initial technical success, 3-year patency was 68% for single short stenoses, as opposed to 20% for long and multifocal stenoses (p = 0.05, logrank test). Antiplatelet therapy with acetylsalicyclic acid was not found to influence occurrence of restenosis. The study documents the poor PTA results for long and multifocal stenoses and suggests precautions to be taken during PTA in order to minimize the area of artery wall damage.

Renal artery dysplasia in a patient with membranoproliferative glomerulonephritis

A 27 year old man with nephrotic syndrome due to membranoproliferative glomerulonephritis had multifocal stenoses of the renal and intestinal arteries. The arterial lesions demonstrated by angiography closely resembled those of medial fibromuscular dysplasia. The dysplasia progressed over a five year period to involve both renal arteries from their extrarenal segments through their interlobar branches. Low serum levels of complement components C3 and C4, focal reduplication of the glomerular basement membrane on light microscopy, and the patterns of glomerular localization of IgG and C3 by immunofluorescence were characteristic of type I membranoproliferative glomerulonephritis. The development of the arterial dysplasia in a patient with chronic glomerulonephritis suggests a common immunologic pathogenesis of both disorders.

Experimental fibromuscular arterial dysplasia.

FIBROMUSCULAR dysplasia has recently interested radiologists, and their investigations (9, 13, 15, 18) have helped to elaborate its pathology and clinical associations. Progression of the disease has been suggested (23) when collateral circulation can be demonstrated. There has been some disagreement on this point, however. One group of investigators (18) reported that repetitive angiographic studies suggested no significant progression after the age of forty years; in another study (13), significant developing lesions were demonstrated in 6 of 16 repeat examinations. This group of lesions has been subdivided and classified into a number of different entities, the most frequent being designated medial fibroplasia with microaneurysms (15), medial fibromuscular dysplasia with multifocal stenosis and mural aneurysms (9, 13), and fibromuscular dysplasia of the media (2). The classification of the remainder of the fibromuscular arterial lesions remains complex as new entities and newer terminologies are described. Whether there is an etiologic relation between any of these smaller divisions and the most common variety has not been evaluated, but many differences in clinical associations have been shown. Harrison et al. (9) sought a common denominator in the dilatation of the vasa vasorum in all groups but questioned whether this indeed represented an attempt at collateral circulation because of associated stenoses. The differentiation between all groups in the early stages of the condition is not easy and the initial stages of all these dysplasias are not well documented. The later differentiation between groups as radiological entities has been evaluated (15), but Meaney and his co-workers (18) indicate that difficulty occurs in some cases, possibly because of merging of histological features between the groups (13). If the early stages could be recognized with certainty, then patient evaluations would be distinctly improved. The early stages of the lesions could be suggested by any irregularity, especially toward the distal end of the renal artery, providing it is not the smooth caliber variety of stationary wave. Meaney and Buonocore (17) indicated that some irregular contractions, initially transitory, may ultimately be fixed, and Harrison commented that the multifocal stenoses of medial thickening may represent a later stage of a small focal or tubular lesion. Peart (24) stressed that the early forms of fibromuscular dysplasia may not be easy to diagnose arteriographically because the smooth changes will not deform the contrast column very prominently. Houser and Baker (10) indicated the differential diagnostic criteria between circular spastic contractions, stationary arterial waves, and dysplastic arterial conditions in the cervical carotid artery, but hinted that re-examination may reveal progression to the developed angiographic appearance in cases in which atypical fibromuscular dysplasia is suggested.

Morphology of fibromuscular dysplasia of the renal artery in renovascular hypertension

The arterial pathology in sixty-six cases of renovascular hypertension due to idiopathic, nonatherosclerotic disruptive and hyperplastic lesions predominantly of the media of renal arteries has been designated under the general category of fibromuscular dysplasia. These lesions usually affected young adults, although their ages ranged from six to seventy-two years (average thirty-eight years). Women were affected more often than men (3 to 1). In most patients hypertension was relieved or ameliorated by surgical treatment. Histopathology and renal arteriography were used in assessing the arterial morphology. Arteriographically, the lesions presented focal (eleven cases), multifocal (thirty-five cases) or tubular (twenty cases) stenoses, which usually involved the distal two-thirds of the artery, and in fifty-eight per cent extended to the trifurcation or major branches. The right renal artery was the site of stenosis in 44 per cent, the left in 18 per cent; lesions were bilateral in 38 per cent of the cases. Histopathologically, the stenoses were predominantly due to medial thickening in forty-four cases, perimural fibrosis in sixteen cases and dissecting aneurysm in six cases. Multifocal stenoses due to medial thickening and multiple mural aneurysms were the most frequent type and produced a beaded appearance in the arteriogram. Contraction of disrupted segments contributes to the appearance of medial thickening and increases the degree of stenosis. Saccular or fusiform aneurysms developed apparently from mural aneurysms in nine cases. Mural aneurysms occurred in six cases and saccular or fusiform aneurysms in three cases of perimural fibrosis. Dissecting aneurysms involving both the main artery and its branches produced tubular stenosis of the lumen and acute hypertension in all six cases; renal infarcts were found in all six cases. Related disease in vessels other than the renal arteries was rare. Although the basic cause is uncertain, the vasa vasorum may have some role in the production of or the variations in the morphology of this unusual arterial disease. In the individual case of renovascular hypertension due to fibromuscular dysplasia, descriptive diagnosis still remains the most useful tactic and should include a description of the type of stenosis—whether focal, multifocal or tubular—the association with mural, saccular fusiform or dissecting aneurysm, and its distribution in the arterial tree.