The vasa vasorum and angioplasty

Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances.     

Relation between changes in severity of coronary artery stenosis and anginal patterns

Although myocardial ischemia causes angina pectoris, angina and the severity of coronary artery stenosis in individuals do not correlate. However, changes in anginal status over time correlated with changes in the severity of coronary artery stenosis as determined by repeated coronary arteriograms has not been previously studied. Coronary arteriograms, done both at entry into the Program on the Surgical Control of the Hyperlipidemias (POSCH) and 3 years later, were blindly graded for changes in overall severity of coronary artery stenosis according to protocol by the POSCH Arteriography Review Committee. Arteriographic and clinical data from 376 control subjects (347 men, 29 women) were analyzed. There was no statistically significant relation over a long-term (3 year) period between the absence, presence, development, or disappearance of angina pectoris and changes in coronary artery stenosis severity as determined by coronary arteriography. © 1994 Wiley-Liss,Inc     

A useful projection for demonstrating the bifurcation of the pulmonary artery

Summary The demonstration of the pulmonary bifurcation is important in order to exclude pulmonary branch stenoses. The origin of the right and left pulmonary arteries can be demonstrated in the anteroposterior plane if cranial angulation is used. Depending on the course of the left pulmonary artery, the origin of the left pulmonary artery may not be seen in spite of the maximal cranial angulation. On the lateral plane without tube angulation the origin left pulmonary artery is commonly superimposed on the origin of the right pulmonary artery. If maximum caudal angulation is added to the steep left anterior oblique view, not only the left, but also the origin of the right pulmonary artery can be seen.     

Angiodysplasia of the right colon treated by embolization with ivalon (polyvinyl alcohol)

Angiodysplasia of the colon is being recognized with increasing frequency as a source of lower gastrointestinal bleeding in the elderly. In one patient with colonic angiodysplasia, superselective segmental embolization of the ileo-colic artery with Ivalon resulted in the cessation of bleeding without causing bowel infarction. However, because of the development of collateral branches to the angiodysplastic malformation, bleeding recurred. While colectomy remains the treatment of choice in younger patients, in high risk patients embolization with a permanent embolic material, such as Ivalon, is an attractive alternative.     

A device to measure roentgenographic structures.

A simple device and a nomogram are presented to permit rapid, accurate measurement of structures shown on roentgenograms. The arrangement is designed specifically for measurement of coronary vessels, but it can be adapted to other structures.