Open pulmonary biopsy.

Dr. Rainer points out the difficulty in distinguishing poststenotic dilatation from coronary arterial aneurysm. When we first became interested in this problem, we reviewed the literature and talked to other angiographers about the criteria to be used. It became clear that coronary arterial aneurysms are easy to idenhfy if there is no associated coronary atherosclerosis. In the face of coronary atherosclerosis, if the aneurysm is prestenotic for a considerable length and distance, there is no question. If the aneurysm occurs after an atherosclerotic obstruction, the criteria depend on the diameter of the vessel and the length of the dilatation. From our reading of the literature, as well as discussions with other cardiologists, we chose the following criterion to separate coronary arterial aneurysm from poststenotic dilatation: an increase in the vessel's diameter two times its usual diameter over a length of at least 2 cm. In a prospective study of 742 patients, this criterion seemed to easily separate poststenotic dilatation from coronary arterial aneurysm. In fact, coronary arterial aneurysms usually have dilatation of the coronary artery for the majority of the vessel's length. Until other criteria become available, we believe this is still the best one.