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Biomedical subjects

A W Stanson

Publications and source records attributed to A W Stanson.

At least 73 records · Page 4Linked to original sources
PubMed1989

Incidental fibromuscular dysplasia in potential renal donors: long-term clinical follow-up.

The clinical natural history of renal arterial fibromuscular dysplasia (FMD) in patients with normal blood pressure is unknown, to the authors' knowledge. The authors reviewed the results of 1,862 renal angiograms obtained in potential renal donors. FMD was present in 71 patients (3.8%). The average age at which FMD was discovered was 50.8 years. Seventy-five percent of the patients with FMD were female. Of 30 patients who did not undergo nephrectomy, eight (26.6%) developed hypertension over a mean followup interval of 7.5 years. Of 19 patients who underwent nephrectomy, despite the presence of FMD, five (26.3%) developed hypertension over a mean follow-up interval of 4.4 years. In comparison, three subjects (6.1%) (from a randomized control group of 49 age- and sex-matched healthy individuals) developed hypertension over a mean follow-up period of 7.1 years. The authors conclude that asymptomatic middle-aged individuals with renal FMD develop hypertension at a rate greater than that of age-matched control subjects with normal blood pressure.

Adult↗
PubMed1988

Percutaneous placement of the Greenfield vena caval filter.

During the period from August 1986 to August 1987, 50 patients underwent percutaneous placement of a Greenfield vena caval filter from the right femoral vein, left femoral vein, or right internal jugular vein at our institution. All 50 patients had a contraindication to anticoagulation therapy or had complications of anticoagulation for deep venous thrombosis or pulmonary emboli. The percutaneous placement was accomplished in the angiographic suite with use of local anesthesia and was well tolerated by all patients. Only three complications related to the percutaneous approach occurred during the short-term follow-up (3 months to 1 year). These complications were deep venous thrombosis of the leg in two patients and misplacement of the filter in one patient. The three patients tolerated these complications well. We conclude that placement of Greenfield vena caval filters can be readily accomplished by means of percutaneous entry. Our experience demonstrated minimal associated morbidity and no mortality.

Aged↗
PubMed1987

Percutaneous transluminal angioplasty in the lower extremities: a 5-year experience.

From January 1979 to March 1984, percutaneous transluminal angioplasty (PTA) was used to treat 148 limbs of 135 Mayo Clinic patients with occlusive arterial disease of the lower extremities. The procedure was technically successful in more than 95% of the attempts. The outcome was clinical improvement in 89 limbs and no improvement in 40 limbs; in 19 limbs, PTA was technically successful but the patient was dismissed from the hospital and lost to follow-up before the extent of improvement could be determined. Mean ankle/brachial pressure indices increased after PTA in those with clinical improvement but not in those without improvement. Clinical improvement was less likely to follow PTA in patients with advanced age, diabetes, severe initial symptoms, low ankle/brachial indices, or distal occlusive disease. In patients with improvement after PTA, the mean follow-up period was 33 months; during that time, failure (defined as recurrence of the original symptoms or the need for repeat PTA or operation) occurred at a rate of 6.4% per year. Serious complications occurred after three procedures (2.0%). We conclude that PTA is technically feasible and generally safe for many patients with occlusive arterial disease of the lower limbs.

Aged↗
PubMed1987

Arterial fibromuscular dysplasia.

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory vascular disease that involves primarily the renal and internal carotid arteries and less often the vertebral, iliac, subclavian, and visceral arteries. Although its pathogenesis is not completely understood, humoral, mechanical, and genetic factors as well as mural ischemia may play a role. The natural history is relatively benign, with progression occurring in only a minority of the patients. Typical clinical manifestations are renovascular hypertension, stroke, subarachnoid hemorrhage, abdominal angina, or claudication of the legs or arms. In patients with symptoms, percutaneous transluminal angioplasty has emerged as the treatment of choice in most involved vascular beds.

Arterial Occlusive Diseases↗
PubMed1987

Deep venous thrombosis and pulmonary embolism. Risk of subsequent malignant neoplasms.

We conducted a noncurrent prospective study of all Olmsted County, Minnesota, residents who had had a lower-extremity venogram, pulmonary angiogram, or lung scan performed because of suspicion of deep venous thrombosis or pulmonary emboli. One hundred thirteen cancer-free patients were followed for 386 person-years from the date of procedure. Nine subsequent cancers were observed compared with 4.5 expected (relative risk, 2.0; 95% confidence interval, 0.9 to 3.8), using total cancer incidence rates for the Rochester, Minn, population. Five hundred seventeen cancer-free controls were followed for 2072 person-years. Twenty subsequent cancers were observed compared with 11.6 expected, yielding a relative risk of 1.7 (95% confidence interval, 1.1 to 2.7). When cases and controls were compared directly, no statistically significant difference in cancer-free survival was found.

Follow-Up Studies↗
PubMed1986

Cogan's syndrome: 18 cases and a review of the literature.

In this article, we review 78 cases of Cogan's syndrome--18 from our institution and 60 from the English medical literature--and describe the clinical, laboratory, radiographic, and pathologic findings associated with this disorder. Patients with Cogan's syndrome should be examined by an ophthalmologist, otolaryngologist, and internist because, in addition to the eye and audiovestibular involvement, systemic manifestations are common. An elevated erythrocyte sedimentation rate, anemia, leukocytosis, and thrombocytosis are common but nonspecific laboratory abnormalities. Serious outcomes include deafness and, less frequently, vasculitis, aortic insufficiency, blindness, and death. Glucocorticoids seem to be effective therapy for active Cogan's syndrome. Aortic valve replacement and vascular bypass grafting are indicated in selected cases. The roles of cytotoxic-immunosuppressive agents and cochlear implantation remain to be clarified.

Adolescent↗
PubMed1986

Penetrating atherosclerotic ulcers of the thoracic aorta: natural history and clinicopathologic correlations.

Clinically, penetrating atheromatous ulceration of the aortic wall may be confused with either symptomatic thoracic aneurysm or classic spontaneous aortic dissection. Aortography and computed tomographic (CT) scanning of the thoracic aorta provide specific diagnostic information which permits one to distinguish this lesion from atherosclerotic aneurysm and classic dissection. Hallmarks of findings on aortography and CT scan include the presence of the ulcer and an intramural hematoma. Since the findings may be disarmingly subtle, the potentially progressive and serious nature of this condition may remain unappreciated. Recognition of the penetrating atheromatous ulcer and distinguishing it from aortic dissection arising just distal to the origin of the left subclavian artery is mandatory. Resection of only a conservative segment of the proximal descending aorta suffices for classic dissection in the upper descending thoracic aorta, but the penetrating aortic ulcer requires graft replacement in the area of the ulcer and intramural hematoma.

Aged↗
PubMed1985

Drug effects on platelet deposition after endothelial injury of the rabbit aorta.

Factors released from platelets deposited on injured endothelium have lately been increasingly implicated in the pathogenesis of atherosclerosis and neointimal hyperplasia. Inhibition of platelet activity has therefore been postulated to protect injured vessels from progressive degenerative disease. The objective of this study was to evaluate the effectiveness of platelet inhibiting drugs in decreasing the deposition of platelets after a standardized endothelial injury of the rabbit aorta. The aortic endothelium of 53 rabbits was denuded with a balloon catheter. Morphological changes were studied with light and electron microscopy in five rabbits. The influence of ibuprofen, acetylsalicylic acid, dipyridamole, verapamil, and prostacyclin upon the deposition of indium-111-labeled autogenous platelets 1 hr after injury was evaluated in 48 animals. The morphological studies demonstrated that platelets were deposited on the denuded aorta but no major platelet aggregation or thrombus formation occurred. The radionuclide studies showed that none of the drugs tested had any significant influence on the deposition of platelets. It is concluded that platelets immediately adhere to injured vessels but that the secondary platelet aggregation is minimal if the injury is limited to the endothelium. Conventional drugs mainly affecting platelet aggregation are ineffective in these circumstances.

Animals↗
PubMed1985

Constrictive pericarditis: assessment of current diagnostic procedures.

Constrictive pericarditis frequently poses a diagnostic challenge because of its varied manifestations. Accurate diagnosis is essential, however, because surgical decortication may yield excellent clinical results. Although new diagnostic procedures have helped the clinician to diagnose constrictive pericarditis, the initial clinical suspicion of this diagnosis must be high for appropriate interpretation of these tests. Echocardiography is useful, primarily for distinguishing various other cardiac abnormalities that may simulate constrictive pericarditis. Computed tomography is a valuable procedure for assessment of pericardial thickening. In addition, evaluation of early diastolic filling by computerized digitization in conjunction with echocardiography, angiography, and invasive hemodynamics shows promise as a diagnostic tool. Even with these new diagnostic aids, distinguishing constrictive pericarditis from restrictive cardiomyopathy may be difficult and, in some cases, may necessitate an exploratory operative procedure.

Aged↗
PubMed1985

Use of radiographically abnormal kidneys in living-related donor renal transplantation.

A retrospective study was undertaken to evaluate the significance of anatomic variants in living-related donor kidneys, when used in renal transplantation. 301 arteriograms were performed in the evaluation of such potential living donors over an 8-year period. 51 (16.9%) were found to have one or more radiographic abnormalities. 20 of the 51 patients (39%) were judged as not suitable for transplantation because of radiographic abnormalities. 7 of 31 patients who were accepted as organ donors declined for personal reasons. The remaining 24 patients underwent donor nephrectomy with the abnormal kidney utilized as the donor organ. In follow-up, none of the kidneys were lost because of their primary radiographic abnormality, and allograft survival of abnormal kidneys was the same as for normal kidneys transplanted under parallel circumstances. We conclude, in properly selected living donors, kidneys with anatomic variants without pathological significance can be used safely in renal allotransplantation. We do not recommend, however, transplanting kidneys with the potential for the development of progressive disease.

Adult↗
PubMed1985

Balloon angioplasty. Natural history of the pathophysiological response to injury in a pig model.

The restenosis or occlusion that frequently follows balloon angioplasty is poorly understood. Thus, the pathophysiological response to angioplasty of the common carotid artery in 38 heparinized normal pigs was investigated by quantification of the 111In-labeled platelet deposition and histological and electron microscopic examination from 1 hour to 60 days after angioplasty. At 1 hour, the following findings were noted: complete endothelial denudation in all arteries, marked platelet deposition (44.7 +/- 20.7 X 10(6)/cm2), mural thrombus in seven of 10 pigs, and a medial tear extending through the internal elastic lamina in nine of 18 arteries. All nine arteries with tears had associated mural thrombus and severe platelet deposition (76 X 10(6)/cm2); in contrast, the nine arteries without a tear had no mural thrombus and much lower platelet deposition (6 X 10(6)/cm2). Necrosis of medial smooth muscle cells was evident at 24 hours. Platelet deposition remained high at 24 hours (40.5 +/- 20.6 X 10(6)/cm2), but was markedly reduced at 4 days (4.4 +/- 1.5 X 10(6)/cm2), coincident with partial regrowth of endothelium or periluminal lining cells. No significant platelet deposition was noted at 7 days, when the endothelial cell type of regrowth was largely complete. Intimal proliferation of smooth muscle cells was mild and patchy at 7 days, significantly greater and more uniform at 14 days, and unchanged at 30 and 60 days after angioplasty. Complete thrombotic occlusion occurred in four (11%) of the 38 pigs. A significant stenosis present at 30 days after angioplasty was shown by histological examination to be due to organization of mural thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1985

Takayasu arteritis. A study of 32 North American patients.

Thirty-two patients (26 female, 6 male) with angiographically diagnosed Takayasu arteritis were seen at the Mayo Clinic between 1971 and 1982. Racial composition of this group was 23 North American Caucasians, 4 Mexicans, 3 Orientals, 1 Native American, and 1 patient of Middle Eastern origin. Incidence of the disease in Olmsted County, Minnesota, was 2.6/million/year. Diagnosis was often delayed for long periods of time, with a median delay of 18 months. Patients had both non-vascular symptoms (arthralgias in 56%, fever in 44%, weight loss in 38%) and symptoms of vascular stenosis such as arm claudication (47%) and hypertension due to renal artery stenosis (41%). All patients had either multiple vascular bruits (94%) or absent pulses (50%). Laboratory findings included anemia (44%) and elevations of erythrocyte sedimentation rate (78%). Almost all patients had multiple sites of arterial involvement documented by angiogram with various combinations of stenosis, luminal irregularity and aneurysm formation. Response to corticosteroid treatment was usually very good, with dramatic improvement in non-vascular symptoms and return of pulses in 8 of the 16 patients with absent pulses prior to treatment. Five-year survival rate from time of diagnosis was 94%. Twelve patients underwent surgical procedures involving the carotid arteries (5 cases), subclavian artery (4 cases) and renal arteries (3 cases). Three aneurysms were resected, one had aortic valve replacement for severe aortic regurgitation, and two patients underwent transluminal angioplasty. Pathologic changes were restricted to the media and adventitial layers of the vessel wall and were indistinguishable from those of giant-cell or temporal arteritis. Takayasu arteritis is more common than previously suspected in North America, is not restricted to any one racial group, and is readily treatable with corticosteroids and surgical vascular reconstruction.

Adolescent↗
PubMed1985

Extensive revascularization in patients with "nonreconstructible" vascular disease.

Elderly patients with severely ischemic lower extremities should undergo thorough noninvasive and angiographic evaluation. Although the visualization of a small nongraftable vessels in the lower extremity is a contraindication to an extensive limb salvage procedure, the inability to visualize angiographically any distal vessels in the lower extremity is not a contraindication. Patients with a severely ischemic but viable lower extremity and angiographic nonvisualization of any distal vessels of the lower extremity should be considered potential candidates for surgical exploration and possible salvage by simultaneous inflow and outflow procedures.

Amputation, Surgical↗
PubMed1984

Digital subtraction angiography.

Digital subtraction angiography is a new technique that combines fluoroscopic and computer technology to image the vascular system. This "angiogram" is fast and safe, can be performed on outpatients, and requires only intravenously administered contrast medium.

Angiography↗
PubMed1983

Renal vein thrombosis in idiopathic membranous glomerulopathy and nephrotic syndrome: incidence and significance.

The point prevalence and clinical significance of renal vein thrombosis (RVT) was evaluated in 27 of 33 consecutive nephrotic patients with idiopathic membranous glomerulopathy. A technique of retrograde venography after the injection of epinephrine into the main renal artery to decrease renal blood flow was used. Two patients had histories compatible with a thromboembolic event, and the excretory urogram was not suggestive of RVT in any patient. RVT was noted in 13 patients; in eight it was bilateral. All patients with RVT received anticoagulant drugs for a minimum of 1 year after the study, and no thromboembolic events occurred in this group. No patient was treated with corticosteroids. Follow-up observation of an average of 2.5 years has not revealed a significant difference in the rate of renal function deterioration or change in degree of proteinuria between patients with and without RVT. Coagulation abnormalities included elevated platelet counts and plasma fibrinogen levels and prolonged reptilase and thrombin times. These were noted in all 14 patients studied, six of whom had RVT. In patients experiencing a nephrotic remission, coagulation abnormalities reverted to normal. RVT is common in idiopathic membranous glomerulopathy with nephrosis and is associated with few clinical markers. Its influence on renal function and proteinuria is of questionable significance. Coagulation abnormalities may be a causative factor of RVT in this setting.

Adult↗
PubMed1983

A perspective of percutaneous transluminal angioplasty.

PTA is a relatively new procedure which is still evolving. More technical improvements are needed. Stiffer balloon plastics and devices to measure arterial wall compliance during balloon inflation are predicted to lead to better long-term success rates. Increasing case numbers provide greater expertise and subsequent refinements in performance and case selection. These factors will lead to improved statistics. Other features of overall patient care must be considered also. The procedure is easy for patients to tolerate, and they can return to activities and work in three or four days. The overall cost is much cheaper than surgery, even at a conservative success rate of 65 percent. There is minimal risk and morbidity, and virtually no mortality. PTA can be repeated if the lesion recurs. Severe complications are rare and almost always surgically treatable. If PTA fails to achieve success, a traditional surgical procedure can be performed. Percutaneous transluminal angioplasty is an important therapeutic alternative to traditional medical and surgical treatment for occlusive arterial disease. It can save legs, veins, time, and money. We need to refine and accurately record the use of this procedure. Total cooperation among clinicians, surgeons, and radiologists is essential for proper utilization of PTA.

Adolescent↗
PubMed1983

Arteriomegaly: classification and morbid implications of diffuse aneurysmal disease.

Ninety-one patients with arteriomegaly and diffuse aneurysmal disease below the level of the renal arteries have been classified according to the extent and location of aneurysmal change. There exists a high incidence of thrombotic and embolic complications, and treatment entails increased rates of morbidity and mortality when compared to surgical treatment of simple abdominal aneurysms of peripheral artery aneurysms. Complete revascularization at the initial operation would appear to give the best result, but this approach must be tempered by the individual patient risk factors and the urgency of the mode of presentation of the patient.

Adult↗