Thomas A. Orszulak

Surgical Pathology of the Mitral Valve: A Study of 712 Cases Spanning 21 Years

The gross surgical pathologic features of the mitral valve were reviewed in 712 patients who had undergone mitral valve replacement at our institution during 1965, 1970, 1975, 1980, and 1985. Among the 452 cases of mitral stenosis, either with or without mitral insufficiency, 99% were attributable to postinflammatory disease and 1% were related to congenital mitral stenosis. Among the 260 cases of pure mitral regurgitation, the two most common causes were a floppy valve (38%) and postinflammatory disease (31%). Moreover, a floppy valve was observed in 73% of the 59 examples of chordal rupture and in 38% of the 16 cases of infective endocarditis. Women accounted for 73% of the 452 cases of mitral stenosis and for 72% of the 530 cases of postinflammatory disease. In contrast, men accounted for 58% of the 260 cases of pure mitral regurgitation, including 76% of the floppy valves and 69% of the infected valves. During the 21 years spanned by the study, the relative frequency of postinflammatory mitral insufficiency progressively decreased, whereas that of floppy mitral valves increased. It is unclear whether aging, heredity, environmental factors, changes in the frequency of acute rheumatic fever, or changes in patient referral practices may account for this observation.

Angioplasty for Aortocoronary Bypass Graft Stenosis

During the period November 1979 to October 1984, 19 patients at our institution underwent balloon angioplasty of partial or complete obstruction of aortocoronary artery saphenous vein bypass grafts. The procedures were performed a mean of 38 months after a coronary bypass operation to relieve recurrent angina of at least class 2 in the Canadian Cardiovascular Association functional classification. Graft angioplasty was successful in 16 of the 19 patients, and the location of the lesion (in the origin, body, or distal insertion of the graft) did not seem to be an important factor in achieving a successful result. At a mean follow-up interval of 20 months (range, 1 to 40 months), 14 patients had symptomatic improvement. Two patients required late repeat operation and four had repeat angioplasty because of restenosis. Our experience supports the use of balloon angioplasty in selected patients with bypass graft stenosis, but restenosis remains a substantial problem.

Hemorrhagic Cardiac Tamponade: A Clinicopathologic Correlation

Staphylococcus aureus pericarditis and recurrent episodes of hemorrhagic cardiac tamponade developed in a 31-year-old man. He later died of exsanguination and at autopsy was found to have a ruptured infective pseudoaneurysm of the aortic arch. When hemorrhagic pericardial effusions of undetermined cause are encountered, the heart and great vessels should be evaluated as potential sources of the hemorrhage.

Initial Experience With Sequential Internal Mammary Artery Bypass Grafts to the Left Anterior Descending and Left Anterior Descending Diagonal Coronary Arteries

Early patency and late patency have consistently been better with single internal mammary artery grafts than with saphenous vein conduits. To determine the efficacy of these two types of grafts in sequential anastomoses, we performed sequential anastomoses of the left internal mammary artery to the left anterior descending and diagonal coronary arteries in 40 patients and compared the results with those in 58 patients who received sequential saphenous vein grafts. Treatment with dipyridamole (starting 48 hours before operation) and aspirin (added 7 hours after operation) was given to the 40 patients with internal mammary artery grafts and to 32 of the 58 patients in the saphenous vein group. After the bypass procedure, mean blood flows were as follows: 68 ml/min in patients with internal mammary artery grafts, 73 ml/min in patients who received saphenous vein grafts and a placebo, and 99 ml/min in those who received saphenous vein grafts, aspirin, and dipyridamole. Early patency of sequential internal mammary artery grafts to the diagonal and left anterior descending coronary arteries was comparable to that of sequential saphenous vein grafts. Because a substantial late reduction in patency has been noted in sequential saphenous vein grafts, sequential internal mammary artery grafts may be the preferred conduit for coronary artery revascularization.