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Biomedical subjects

D C Levin

Publications and source records attributed to D C Levin.

At least 145 records · Page 8Linked to original sources

Suprarenal aortic occlusion.

Proximal propagation of an occlusive distal aortic thrombus to the suprarenal level is rare, probably resulting from diminished renal blood flow, and is invariably accompanied by renal failure. Three similar cases of total suprarenal aortic occlusion with renal failure are presented. In each, one kidney was significantly smaller than the other, probably caused by long-standing disease. The combination of bilaterally absent or markedly decreased femoral pulses with diminished renal function or a unilateral small kidney should therefore be considered dangerous. To prevent proximal propagation of thrombosis and death from renal failure, such patients should undergo arteriography and surgical repair promptly even though their clinical symptoms might be relatively mild and stable.

Acute Kidney Injury↗

Augmented arterial flow and pressure resulting from selective injections through catheters: clinical implications.

Injection of fluid through catheters positioned selectively in arteries results in substantial increases in flow and pressure in those arteries for the duration of the injection. This produces certain artifacts which may lead to misinterpretation of the arteriograms. Apparent direction of flow in major vessels, extent of collateral circulation, distribution of contrast medium throughout various branches of the arterial tree, and density of accumulation of contrast material in organs or tumors can be altered significantly by the injection technique.

Angiography↗

Experimental myocardial infarction in dogs with normal coronary arteries. Angiographic resolution of coronary arterial emboli.

Percutaneous transcatheter embolization of the coronary arteries with autologous clot was performed in six dogs. The occlusions resolved completely within 14 days in the four surviving dogs. Postmortem examination revealed transmural myocardial infarction in two dogs and subendocardial infarcts in the other two. Histological sections showed no residual emboli in three dogs and a recanalized thrombus in an epicardial vessel in the fourth. These findings indicate that myocardial infarction can be produced by multiple occlusions of the distal coronary arterial branches, provided that common or contiguous myocardium is affected. The recanalized thrombus in one dog suggests that the thrombolytic process need not be complete for return to a normal angiographic appearance.

Angiography↗

Hemodynamically significant primary anomalies of the coronary arteries. Angiographic aspects.

Hemodynamically significant primary anomalies of the coronary arteries are those which alter myocardial perfusion. There are four major types: coronary artery fistulae, origin of the left coronary artery from the pulmonary artery, congenital coronary stenosis or atresia, and origin of the left coronary artery from the right sinus of Valsalva, with subsequent passage of the vessel between the aorta and right ventricular infundibulum. The angiographic features of these lesions are discussed.

Arteriovenous Fistula↗

Physiologic effects of bronchopulmonary lavage in alveolar proteinosis.

The clinical and physiologic effects of bronchopulmonary lavage of both lungs at separate times in 14 patients with alveolar proteinosis proved by biopsy were followed for 2 to 96 months. Before lavage, all patients had moderate to severe dyspnea on exertion. Twelve had a nonproductive cough, and 2 had a productive cough; both were smokers. Nine had generalized fatigue, and 4 had weight loss. Twelve of 14 had fine inspiratory rales. All of the patients had abnormal chest roentgenograms, and 13 of 14 had an increased lactate dehydrogenase concentration. After lavage, all patients had loss of fatigue and improved exercise tolerance, with most returning to normal activity. Cough cleared in 12 of 14 and remained only in the cigarette smokers. Inspiratory rales cleared completely in most patients (11 of 12) and partially in one. The rales usually returned during exacerbations. Physiologic measurements that changed significantly after bilateral lavage included: vital capacity, total lung capacity, resting room air PO2, exercise PO2, PO2 while breathing 100 per cent O2, and DLCO. Because all measurements were made within 5 days of the second lavage, one must attribute the acute improvement to the removal of proteinaceous material from the alveoli. The long-term effects varied; some patients required annual or semiannual lavages, wherease others remained in remission after lavage for 36 to 96 months. Exacerbations were accompanied by increased dyspnea, reappearance of rales, and deterioration of the gas-exchange parameters noted previously. Repeat lavage reversed the clinical symptoms and physiologic abnormalities in patients who had recurrences.

Adult↗

Angiographic demonstration of complications resulting from the Waterston procedure.

The ascending aorta--right pulmonary artery anastomosis, originally introduced by Waterston as a palliative shunt to increase pulmonary blood flow in certain cyanotic congenital heart diseases, has been found to be associated with late complications in a significant number of cases. These complications include preferential distribution of most or all shunt flow to the right lung, narrowing or obstruction of the right pulmonary artery at the anastomotic site, increasing stenosis or atresia of the right ventricular outflow tract, hypoplasia of the left pulmonary artery, and obstruction of the shunt itself. A properly planned angiocardiographic study is the principal method of detection of these complications.

Adolescent↗

Intra-arterial radionuclide infusion: a new technique to assess chemotherapy perfusion patterns.

A mechanical infusion pump was used to introduce 99mTc-sulfur colloid at a rate of 1 ml/minute into the hepatic arteries of six patients. The radiotracer distribution patterns were compared to those obtained with "bolus" radionuclide angiography and those seen with standard contrast angiography. In all cases, the slow flow rate radionuclide studies evidenced dramatic differences from the patterns obtained with rapid flow rate injections. The results indicate that standard, rapid-injection contrast techniques may not produce the most reliable information regarding potential flow distribution. It is concluded that radiotracers introduced at flow rates approximating those attained with infusion pumps will offer the best estimates of both initial catheter placement and subsequent patterns of hepatic distribution of chemotherapeutic agents.

Adult↗

Bacteremic hemophilus influenzae pneumonia in adults. A report of 24 cases and a review of the literature.

Twenty-four cases of Hemophilus influenzae pneumonia diagnosed by positive blood or pleural fluid cultures are compared to 43 cases previously reported in the literatrue. Frequently associated illnesses in both series include alcoholism, chronic airways obstruction and preceding respiratory tract infection. Moderate temperature elevation and slight leukocytosis were common on admission in both groups. Chest roentgenograms in our series revealed both bronchopneumonia (75 per cent) and lobar consolidation (38 per cent). Pleural disease occurred frequently, with two empyemas noted on admission and nine additional effusions developing during therapy. Treatment of choice was ampicillin. All five patients who did not receive ampicillin died, whereas 16 to 19 who received this drug survived. High mortality (33 per cent) in our series may be attributed to the advanced age of the patients and the presence of associated illnesses. In addition, a 10 year review suggests a true increase in the incidence of H. influenzae pneumonia in adults.

Adult↗

Left ventricular performance and graft patency after coronary artery-saphenous vein bypass surgery: early and late follow-up.

Left ventircular performance and graft patency were studied postoperatively at 2 weeks in 19 patients, and at 9 months in 15 patients. At early follow-up, left ventricular ejection fraction and mean rate of circumferential shortening were unchanged for the group as a whole, but were slightly improved in patients who had had a moderately abnormal preoperative ejection fraction of 0.30 to 0.60. At late follow-up, 10 of 14 patients had occluded at least one graft or the proximal segment of the grafted coronary artery and had an associated decrease in ventricular function. The risk of graft occlusion was greater if the preoperative ejection fraction was decreased; seven of 10 patients with a preoperative EF of less than 0.60 suffered one or more graft occlusions, but only three of 16 patients with a preoperative EF greater than 0.60 had a postoperative graft occlusion (p is less than 0.05). The results suggest that bypass graft surgery is not generally indicated as a measure to improve ventricular function in patients with ischemic heart disease.

Angina Pectoris↗

Angiography of nonfunctioning pheochromocytomas of the adrenal gland.

Two patients with clinically nonfunctioning pheochromocytomas of the adrenal gland were studied angiographically. The radiological characteristics were indistinguishable from those of functioning pheochromocytomas. In patients with hypervascular adrenal masses, the diagnosis of pheochromocytoma should be considered even in the absence of customary signs and symptoms.

Adrenal Gland Neoplasms↗

Wandering spleen--the radiological and clinical spectrum.

Eight cases of wandering spleen demonstrate that this rare entity has a characteristic constellation of findings which, though nonspecific, are highly suggestive of the diagnosis. Angiography or isotopic imaging specific for the spleen confirms the diagnosis. Asymptomatic patients may be carefully observed, with the institution of splenectomy should signs of torsion develop.

Adult↗

The role of the radiologist in coronary angiography.

Radiology chiefs at hospitals with open heart surgery programs were queried to ascertain both current and desired degrees of participation by radiologists in coronary angiography. While current participation is limited, respondents indicated a desire to achieve increased active participation. Opposition of cardiologists and a shortage of trained cardiac radiologists were perceived as principal factors impeding increased participation. Over two thirds of the respondents felt additional cardiac radiology training programs are needed and many indicated that positions were available in their departments for a trained cardiac radiologist.

Angiography↗

Participation by radiologists in coronary angiography.

Coronary angiography is one of the few radiologic procedures which remains largely under the control of another medical specialty. There are several contributing reasons, none of which justify continuation of this situation. A more active role for radiologists in performing coronary angiography is urged.

Angiography↗

Arteriography in the evaluation of pancreatic pseudocysts.

A policy of limiting preoperative diagnostic imaging of pancreatic pseudocysts to barium studies, sonography, or computed tomography will result in failure to detect frequently associated lesions which may only be appreciated by arteriography and which radically alter both the prognosis and surgical approach. These associated lesions include: (1) pseudoaneurysms, probably the most common cause of major gastrointestinal hemorrhage in pseudocyst patients; (2) pancreatic carcinoma, a possible etiologic factor leading to formation of the pseudocyst; (3) benign or malignant cystadenomas which mimic pseudocysts clinically but can be usually identified arteriographically by prominant neovascularity; and (4) splenic vein obstruction which can produce extrahepatic portal hypertension and necessitate splenectomy. In our experience, these complicating lesions are relatively common. Their preoperative detection is desirable and is best accomplished by arteriography. For this reason, arteriography should be routinely performed in patients suspected of pancreatic pseudocyst.

Adenocarcinoma↗

Cardiomegaly as a cause of nonuniform pulmonary artery perfusion.

In patients with cardiomegaly, a common cause of nonuniform pulmonary artery perfusion on pulmonary arteriograms is compression of the left lower lobe arteries by the enlarged heart, an effect which is accentuated by gravity in the supine position. This may impede flow in such a manner as to erroneously suggest the presence of pulmonary emboli. Subselective left lower lobe arteriography with the patient in the right posterior oblique position will allow better anatomic definition of the vessels in this region and result in fewer equivocal or false positive studies.

Adult↗