Zeev Vlodaver

Correlation of the Antemortem Coronary Arteriogram and the Postmortem Specimen

Correlative studies were carried out on the coronary arteriograms made during diagnostic procedures and on the specimens obtained at necropsy in 10 cases of coronary heart disease. Of the 134 segments of coronary arteries available for both studies, 44 (33%) were given false-negative arteriographic diagnosis of obstructive atherosclerosis.Factors which may underlie this discrepancy include (1) radiographic technic, (2) projection used, (3) a slitlike lumen adjacent to the atheroma, (4) comparison of severely obstructed segments involved but less severely obstructed, and (5) misinterpretation from the specimen of obstruction present in life.

Pathologic changes in aortic-coronary arterial saphenous vein grafts.

This is a pathologic study of segments of saphenous vein used as a graft between the aorta and a coronary artery in the surgical treatment of coronary atherosclerosis. Except for an occasional case with thrombotic occlusion of the graft, no lesions were observed in grafts which had been in place for less than 1 month. In each of two grafts in place for 1 month, mild fibrous thickening of the intima was present. Eight grafts which had been in place for 3½ months or longer consistently showed lesions, either organized thrombi (two grafts) or intimal fibrotic proliferative lesion (six grafts). In this group, five of the six grafts with intimal fibrous proliferation showed near or complete occlusion of the lumen.The intimal fibrous proliferative lesion appears primarily to be a response to arterial pressure within the segment of vein. Obstructive atherosclerosis in the artery beyond the anastomosis with the graft may favor the development of the intimal lesion. The intimal lesion may progress rapidly according to the data in one of the cases. In this, patency of the graft demonstrated angiographically 3½ months after the operation was followed by near-complete occlusion of the lumen by the proliferative lesion 3 weeks following demonstration of patency.

Pathology of coronary atherosclerosis.

Abstract Histologic examination of coronary arteries reveals many features of pertinence. In infants, a new layer, the musculo-elastic layer, develops focally associated with thickening of the intima. Later in life, distinction of this normal process from pathologic states may be difficult. In cross sections, two types of lesions are seen: one purely fibrous and the other, a pairing of lipid pools and walling fibrous tissue (the “parite”). Lipid may be seen in phagocytes, as pools and in collagen, the latter, whether part of a fibrous lesion or part of a parite. Lipid collagen may be termed “collipid.” In established atherosclerosis, an episodic character to the development of atherosclerosis is strongly supported. Intimal hemorrhages rarely narrow the lumen but may underlie formation of thrombi. Calcification in atheromas is a sign of age of the lesion, but by itself has no direct bearing on the severity of luminal obstruction by the atheroma. The location and the shape of the arterial lumen in segments with severe sclerosis varies. The lumen may be central or eccentric. In about one-quarter of obstructed segments, the lumen is eccentric and slit-like. This is perhaps the basis for a false-negative arteriographic reading. Study of the distribution of atheromatous lesions indicates that the segment of the right coronary artery between the marginal and posterior descending arteries is the most commonly involved of all segments in the conorary tree. Second to this site is the proximal half of the anterior descending coronary artery.

Correlation of electrocardiographic and pathologic findings in healed myocardial infarction

A correlative study in 50 cases of healed myocardial infarction compared the 12 lead electrocardiogram with pathologic observations. The electrocardiogram was interpreted according to established Minnesota codes with some modifications. The following conclusions were reached: (1) The electrocardiogram underestimates the extent of myocardial infarction. (2) When a healed myocardial infarct at a specific location is recognized with electrocardiographic criteria, it is likely that there are unrecognized infarcts involving other areas of the left ventricle. (3) Infarctions involving the lateral and inferobasal areas are frequently unrecognized. (4) The electrocardiogram is more likely to miss myocardial infarcts in patients with multiple, than in those with single, electrocardiographically diagnosed infarcts. (5) Apical myocardial infarction does not appear to have specific electrocardiographic findings, other than those related to general infarct localization by electrocardiogram, particularly in patients with anteroseptal or anterolateral infarction. (6) Abnormal Q waves, generally thought to indicate transmural myocardial infarction, are frequently found in subendocardial infarction. (7) The simplified electrocardiographic classification of myocardial infarct site (anteroseptal, inferior, anterolateral) used in this study is preferable to more detailed classifications previously suggested by others.

In vitro and in vivo experimental evaluation of a new vena caval filter.

PURPOSE A new stainless steel (MP35N alloy) vena cava filter without a central stasis point was evaluated in vitro and in vivo. MATERIALS AND METHODS The clot-trapping efficiency and hemodynamic flow pattern of the filter were assessed in a flow model and were compared with those of currently available commercial filters including the Vena Tech-LGM, Simon nitinol, Greenfield, and Birds Nest filters. The new filter was placed in the inferior vena cava (IVC) of 31 dogs; 21 of the 31 dogs were followed up with cavography for up to 3 months. At the termination of the study, the filters and IVCs were examined grossly and histologically. An in vivo clot-trapping test was carried out in five dogs. RESULTS The least turbulence was noted with the new filter and the titanium Greenfield filter. The stainless steel Greenfield and Simon nitinol filters caused major flow disturbances. Migration within 5 cm of initial placement occurred in two animals (9.5%). There were no IVC thromboses, perforations, or filter embolizations. An in vivo clot-trapping study showed an 80% efficiency for small thrombi (3 x 20 mm) and 100% efficiency for large thrombi (6 x 20 mm) with the new filter. The Simon and the new filter had the best clot-trapping capabilities. The Vena Tech-LGM and Birds Nest filters were slightly inferior and the Greenfield filter demonstrated by far the lowest trapping capacity. CONCLUSION The new vena cava filter is easily introduced percutaneously through a 12-F sheath and appears to be very promising due to its high filtering capability, low turbulence, nonmagnetic properties, good mechanical stability, and hypothrombogenicity. Clinical trials are warranted.

Pathology of Angina Pectoris

Among the wide variety of causes of angina pectoris, two major categories may be recognized: the anatomic, causing arterial obstruction, and the functional.The anatomic causes may be divided according to anatomic sites as follows: (1) the major coronary arterial trunks and their epicardial branches, (2) the coronary ostia at the aorta, and (3) the intramyocardial “small” arteries. The major coronary arteries are by far the most common sites for anatomic lesions. Atherosclerosis in its various anatomic manifestations is responsible for about 90% of the cases of angina. Commonly, hypertension and, less commonly, valvular disease are associated. The balance of cases of angina result from various states given below. Nonatheromatous diseases of the major coronary arteries include embolism, primary dissecting aneurysm of a coronary artery, arteritis, and anomalous communication of a coronary artery. Coronary ostial narrowing results from various diseases of the aorta including atherosclerosis, saccular and dissecting aneurysm, inflammation, and calcification of the aorta in relation to origin of a coronary artery. Lesions causing obstruction of the intramyocardial arteries are commonly part of systemic diseases such as hematologic, embolic, metabolic, and degenerative.Functional causes of angina pectoris include aortic valvular disease and functionally related conditions, thyroid disease, and pulmonary hypertension.

Nonatherosclerotic Ischemic Heart Disease

Atherosclerosis predominates as the pathologic lesion in coronary artery disease. Less commonly, other nonatherosclerotic etiologic processes involve the coronary arteries, with or without symptoms. This chapter explores the nonatherosclerotic etiologies of coronary artery disease, from spontaneous and device-induced vasospasm to spontaneous coronary artery dissection, vasculitis, embolism, aneurysm, and microcirculatory coronary disease to the impact of chest irradiation, heart valve transplants, congenital conditions, and cocaine use.

Experimental myocardial infarction in the closed-chest dog: A new technique

The reliable and safe production of myocardial infarction in closed-chest animals is of paramount research interest. To date, the injection of particulate matter and the introduction of occlusive solid plugs have been described. Because of the limited size of the catheter, only small branches could be occluded, which resulted in a high incidence of mortality. A new simple technique is described that allows occlusion of a major coronary artery at a preselected site. An Ivalon (polyvinyl alcohol) plug compressed around the tip of an introducing wire is advanced through a selectively placed catheter into the coronary artery. It is felt in place for 5 minutes and assumes its original size upon contact with blood. Once the plug is re-expanded, the wire is withdrawn. The new technique was carried out successfully on nine dogs with no immediate fatality and myocardial infarction as demonstrated by cine ventriculography and histopathologic examination.

Coronary atherosclerosis in subjects with mitral stenosis.

The coronary arteries were examined in 60 specimens from patients with mitral stenosis. In three, localized obstruction was nonatherosclerotic in nature (in one, arterial dysplasia; in two, embolic). In 18 of the remaining 57 cases (31.5%), significantly obstructive atherosclerosis in one or more segments of the coronary arterial system was found. This represented 46% of the males and 27% of the females. The incidence of involvement of three or more arteries by significantly obstructive atherosclerosis was 39%, while in a cited series of subjects with angina pectoris three or more vessels were involved in 79% of the cases. It may be concluded that, on the average, the distribution of lesions in patients with mitral stenosis and significant coronary atherosclerosis is less wide than in subjects with clinical coronary disease.

The biocompatibility of compressed collagen foam plugs

The tissue reaction to reexpanded, purified bovine collagen sponge placed percutaneously into the lung, pleural space, liver, kidney, and muscle was studied in dogs and rabbits. In addition, the biocompatibility and radiopacity of tantalumtreated collagen foam plugs was examined. No adverse effects were found. We believe that collagen plugs may be of use in occluding needle tracts from biopsy sites to prevent complications such as bleeding or pneumothoraces.