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Study of small coronary vessels by X-ray magnification and image amplifier television fluoroscopy
128
Abstracts
erations has demonstrated the feasibility of extending this approach to disabled patients with more extensive disease. The technics utilized include endarterectomy, arteriotomy with vein patch, replacement of entire coronary segments with endto-end vein grafts and, occasionally, combined reconstructive procedures and arterial implants. Two years ago we presented our early experience with this approach. In the first half of that series, op erative mortality was 35%. Experience in the selection of patients and improvement in surgical technics have reduced this mortality to 13% in the second half of the series. Thirty patients who survived 6 months to 6 years have been evaluated by clinical history, exercise electrocardiography and coronary arteriography. Initial results were classified as excellent in 25, good in 4 and unimproved in 1. Of 29 patients with excellent or good results 6 experienced late recurrence of angina. One of these 6 has been reoperated upon and is presently asymptomatic. Another has a patent reconstructed right coronary artery but subsequently occluded anterior descending coronary artery. In 4 patients there was narrowing or occlusion of a reconstructed segment secondary to scar formation. Recurrent atherosclerosis occurred in none. Cinearteriograms and exercise electrocardiograms demonstrating present criteria for selection of operative candidates and evaluation of postoperative patients will be presented. Results After Complete Correction of Truncus Arteriosus. D. C. MCGOON, M.D., R. B. WALLACE, M.D., P. A. ONGLEY, M.D., F.A.C.C. and G. C. RASTELLI, M.D., Rochester, Minn. Complete repair of truncus arteriosus has now been performed at the Mayo Clinic in 8 patients, aged 13 months to 8 years, using a new surgical technic. Three patients had type I truncus arteriosus, 3 had type II, 1 type III and 1 had type IV. Additional complicating features were present in 2 patients: severe pulmonary vascular obstructive disease in 1, and in the other severe insufficiency of the truncus valve which required its replacement with a prosthetic valve: both patients died postoperatively with low cardiac output. Six patients now are asymptomatic and leading normal lives. Follow-up extends to 14 months. In all patients a new pulmonary artery and valve were constructed using a homograft of the ascending aorta including the aortic valve. Electrocardiographic, roentgenographic, cardiac catheterization and angiocardiographic data obtained after operation will
be presented. Calcification in the aortic wall portion of the homograft has occurred in most patients. Calcification of the grafted valve has not yet occurred. Similar observations were made in dogs that survived 2 years with an aortic homograft in place of the pulmonary artery. The significance of these changes in relation to long-term prognosis will be discussed. Study of Small Coronary Vessels by X-Ray Mag nification and Image Amplifier Television Fluoroscopy. W. MCLAUGHLIN, A. A. TAMBE, M.D. and H. A. ZIMMERMAN,M.D. F.A.c.c., Cleveland, Ohio. Previously reported work has described a means of increasing the range of small vessel visibility by applying optical magnification in the tine camera to enlarge the image amplifier light image before it is recorded on the film. A practical limit of magnification at this level seems to be about 3X. A new approach is now being used to remove the inherent resolution limits of the image intensifier tube and the associated television system. The usual resolution limit is about 40 to 50 line pairs per inch as measured at the input surface of the image intensifier. A television system of reasonable quality will resolve a maximum of about 300 line pairs total. The usual practical result is a combination that will resolve individual vessels down to about 300 to 400 p in diameter. The new approach consists of magnifying the x-ray image as presented to the image intensifier by means of geometrical projection. This requires a special x-ray source and associated control means. Further magnification is employed in the optical coupling between the image intensifier and the TV camera tube to achieve maximal total resolution. This approach visualizes vessels of about 100 p diameter as seen in some animal studies in which vessels were available for measurement. To date, high contrast test objects, such as small tungsten wires, have been seen down to about 20 p in diameter. The recording means is preferably videotape. The kinescope recorder can be used, but a special filming system and projection system is needed to retrieve all the information presented. Congenital Ventricular
Pulmonary Valve Atresia with Intact Septum. W. W. MILLER, M.D., N. BELIGERE, M.D., J. A. WALDHAUSEN,M.D., F.A.c.c., J. CHAT-TEN, M.D. and W. J. RASHKIND,M.D., Philadelphia, Pa. Patients with congenital pulmonary valve atresia and intact ventricular septum (PA-IVS) usually die in infancy. The current methods for treating THE
AMERICAN
JOURNAL
OF CARDIOLOGY
Abstracts
erations has demonstrated the feasibility of extending this approach to disabled patients with more extensive disease. The technics utilized include endarterectomy, arteriotomy with vein patch, replacement of entire coronary segments with endto-end vein grafts and, occasionally, combined reconstructive procedures and arterial implants. Two years ago we presented our early experience with this approach. In the first half of that series, op erative mortality was 35%. Experience in the selection of patients and improvement in surgical technics have reduced this mortality to 13% in the second half of the series. Thirty patients who survived 6 months to 6 years have been evaluated by clinical history, exercise electrocardiography and coronary arteriography. Initial results were classified as excellent in 25, good in 4 and unimproved in 1. Of 29 patients with excellent or good results 6 experienced late recurrence of angina. One of these 6 has been reoperated upon and is presently asymptomatic. Another has a patent reconstructed right coronary artery but subsequently occluded anterior descending coronary artery. In 4 patients there was narrowing or occlusion of a reconstructed segment secondary to scar formation. Recurrent atherosclerosis occurred in none. Cinearteriograms and exercise electrocardiograms demonstrating present criteria for selection of operative candidates and evaluation of postoperative patients will be presented. Results After Complete Correction of Truncus Arteriosus. D. C. MCGOON, M.D., R. B. WALLACE, M.D., P. A. ONGLEY, M.D., F.A.C.C. and G. C. RASTELLI, M.D., Rochester, Minn. Complete repair of truncus arteriosus has now been performed at the Mayo Clinic in 8 patients, aged 13 months to 8 years, using a new surgical technic. Three patients had type I truncus arteriosus, 3 had type II, 1 type III and 1 had type IV. Additional complicating features were present in 2 patients: severe pulmonary vascular obstructive disease in 1, and in the other severe insufficiency of the truncus valve which required its replacement with a prosthetic valve: both patients died postoperatively with low cardiac output. Six patients now are asymptomatic and leading normal lives. Follow-up extends to 14 months. In all patients a new pulmonary artery and valve were constructed using a homograft of the ascending aorta including the aortic valve. Electrocardiographic, roentgenographic, cardiac catheterization and angiocardiographic data obtained after operation will
be presented. Calcification in the aortic wall portion of the homograft has occurred in most patients. Calcification of the grafted valve has not yet occurred. Similar observations were made in dogs that survived 2 years with an aortic homograft in place of the pulmonary artery. The significance of these changes in relation to long-term prognosis will be discussed. Study of Small Coronary Vessels by X-Ray Mag nification and Image Amplifier Television Fluoroscopy. W. MCLAUGHLIN, A. A. TAMBE, M.D. and H. A. ZIMMERMAN,M.D. F.A.c.c., Cleveland, Ohio. Previously reported work has described a means of increasing the range of small vessel visibility by applying optical magnification in the tine camera to enlarge the image amplifier light image before it is recorded on the film. A practical limit of magnification at this level seems to be about 3X. A new approach is now being used to remove the inherent resolution limits of the image intensifier tube and the associated television system. The usual resolution limit is about 40 to 50 line pairs per inch as measured at the input surface of the image intensifier. A television system of reasonable quality will resolve a maximum of about 300 line pairs total. The usual practical result is a combination that will resolve individual vessels down to about 300 to 400 p in diameter. The new approach consists of magnifying the x-ray image as presented to the image intensifier by means of geometrical projection. This requires a special x-ray source and associated control means. Further magnification is employed in the optical coupling between the image intensifier and the TV camera tube to achieve maximal total resolution. This approach visualizes vessels of about 100 p diameter as seen in some animal studies in which vessels were available for measurement. To date, high contrast test objects, such as small tungsten wires, have been seen down to about 20 p in diameter. The recording means is preferably videotape. The kinescope recorder can be used, but a special filming system and projection system is needed to retrieve all the information presented. Congenital Ventricular
Pulmonary Valve Atresia with Intact Septum. W. W. MILLER, M.D., N. BELIGERE, M.D., J. A. WALDHAUSEN,M.D., F.A.c.c., J. CHAT-TEN, M.D. and W. J. RASHKIND,M.D., Philadelphia, Pa. Patients with congenital pulmonary valve atresia and intact ventricular septum (PA-IVS) usually die in infancy. The current methods for treating THE
AMERICAN
JOURNAL
OF CARDIOLOGY