Circumferential venolysis and paraclavicular thoracic outlet decompression for "effort thrombosis" of the subclavian vein.

Effort thrombosis of the subclavian vein (Paget-Schroetter syndrome) has long been considered a primary thrombotic process, but recent experience suggests that it may commonly result from repeated mechanical compression. Increased awareness of the pathophysiology of this syndrome can allow timely, improved diagnostic screening and the use of specific surgical intervention to relieve the venous consequences. During the past 15 years we have treated six patients with mechanical compression in the thoracic outlet causing surgically correctable venous occlusive problems.

Management of pararenal aneurysms of the abdominal aorta.

The operative treatment of 77 patients with atherosclerotic aneurysms of the pararenal aorta (54 juxtarenal and 23 suprarenal) is analyzed. Repair of these complex lesions is formidable because of difficult exposure, renal ischemia and myocardial strain as a result of proximal aortic occlusion, and associated renal atherosclerosis with secondary renal functional impairment. Nineteen (25%) patients were normotensive with normal renal function.

Operative treatment of juxtarenal aortic atherosclerosis.

Symptomatic juxtarenal aortic atherosclerosis is a rare and threatening form of aortic disease. The formidable implications of complex aortic reconstruction, the high operative mortality and morbidity rate and the uncertainties regarding the beneficial effects of operation combined to foster highly conservative attitude regarding management. Our reported experience and a brief review which has been highlighted in this report, support an aggressive use of combined aortic and renal branch repair rather than a staged repair or medical management.

Juxtarenal aortic atherosclerosis. Surgical experience and functional result.

Ninety patients underwent combined aortic (90) and renal artery (138 arteries) reconstruction for severe, symptomatic aortic occlusive disease (47 patients), aortic aneurysmal disease (30 patients), and visceral atherosclerosis (13 patients). Transaortic endarterectomy was used for 67% of renal artery reconstructions and 69% of visceral arteries. Aortic reconstruction required prosthetic grafting in 74%.

Canine left ventricular mass estimation by two-dimensional echocardiography.

This study was designed to develop a two-dimensional echocardiographic method of measuring the mass of the left ventricle. The general formula for an ellipse was used to derive an algorithm that described the shell volume of concentric truncated ellipsoids. In 10 canine left ventricular two-dimensional echocardiograms, this algorithm accurately predicted postmortem left ventricular mass (r = .

Measurement of regional changes in myocardial perfusion using dynamic computed tomography and contrast medium.

Changes in regional myocardial perfusion were measured using rapid sequence dynamic transmission tomography to detect differences in the initial distribution of contrast medium injected as an intravenous bolus. The experiments were carried out on 8 mongrel dogs instrumented with flow probes and vascular occluders around the coronary arteries. Flow reductions of 50 per cent or more were detected as regions of myocardium with less contrast enhancement than those with normal perfusion.

Ventricular diastolic pressure-volume relations and the pericardium. Effects of changes in blood volume and pericardial effusion in dogs.

We investigated the role of the pericardium in the mechanism of shifts in the left ventricular (LV) diastolic pressure-volume relation produced by changes in circulating blood volume and by pericardial effusion. Twelve closed-chest anesthetized dogs were instrumented with pericardial and pleural balloons and intracardiac catheters for pressure measurements. We measured the volumes of the pericardium and the left and right ventricles by computed tomography (CT), integrating the area of CT cross-sections measured at 1-cm intervals from the cardiac apex to the aortic arch.

Detection of intraventricular thrombi by computed tomography.

Intraventricular thrombosis (usually occurring after myocardial infarction) can lead to embolization, with serious consequences. Angiocardiography and two-dimensional echocardiography both are limited in their ability to detect intraventricular thrombi. Computed tomography (CT) with intravenous administration of contrast material gave excellent definition of intraventricular thrombi in three patients with recent myocardial infarctions and in one patient with a pericardial patch of the right ventricular apex.

Detection and quantitation of myocardial infarction in vivo using transmission computed tomography.

In vivo studies were performed on 28 dogs to evaluate the usefulness of transmission computed tomography (CT) in the detection and quantitation of experimentally induced myocardial infarction. Intravenously administered contrast material was required to define the internal structure of the heart and to differentiate normal from infarcted tissue. Transmural infarcts with homogeneous central regions were visualized as areas of diminished contrast enhancement compared with the normal myocardium.

Colonic mucin secretion related to non-contractile motility in the dog.

In 8 dogs a colonic pouch with fistula was surgically created. Mucin secretion was measured by washing mucus out of the pouch and then, after a number of chemical steps, by determining the turbidity with spectrophotometry. The movement of tantalum particles insufflated into the canine rectum during periods of absence of contractions was correlated with mucus secretion in the pouch.

Myocardial infarction in dogs, demonstrated by non-enhanced computed tomography.

The capability of non-enhanced and enhanced CT scanning of the heart without ECG gating to detect myocardial infarction in living dogs was explored. CT findings were correlated with those at post mortem. In large transmural infarctions, areas of lower attenuation were detected without contrast medium enhancement and appeared as defects when intravenous contrast medium was administered.

Utility of computed tomography in the diagnosis of thoracic aneurysm in childhood.

For an unusual case of saccular aneurysm of the thoracic aorta in a child, the computed tomographic demonstration of a totally vascular mass led directly to the definitive diagnosis by angiocardiography and eliminated the need for many additional imaging or chemical tests. This case illustrates how computed tomography can be beneficial in the potentially difficult diagnostic evaluation of pediatric medistinal masses.

Evaluation of dissections and aneurysms of the thoracic aorta by conventional and dynamic CT scanning.

Conventional computed tomography (CT) with intravenous contrast injection effectively demonstrates the features of aneurysms of the thoracic aorta (dilatation, calcification, intraluminal thrombus, and displacement and erosion of adjacent structures). In aortic dissection, CT can establish the diagnosis by demonstrating (a) double channels with an intimal flap or (b) displaced intimal calcifications if one channel is thrombosed. Dynamic CT following a contrast bolus shows the relative rate of filling of the true and false channels and demonstrates the intimal flap with optimum clarity.

[Experience with computed transmission tomography of the heart in vivo].

Cardiac computed tomography in its present form provides useful information about the heart for clinical use in patients with heart disease and for investigative work in such patients and living animals. Its great reconstructive power and unmatched density resolution are particularly advantageous in the study of ischemic heart disease. Because of its non-invasive character cardiac computed tomography has the potential of becoming an effective screening tool for large numbers of patients with suspected or known coronary heart disease.