Peter W. Conrad

Hemochromatosis heart disease: An unemphasized cause of potentially reversible restrictive cardiomyopathy

Cardiac involvement in hemochromatosis typically results in congestive cardiomyopathy; a restrictive cardiomyopathy due to hemochromatosis is distinctly rare. A restrictive cardiomyopathy, which developed in the patient described in this report, was due to hemochromatosis which mimicked constrictive pericarditis clinically, echocardiographically and hemodynamically, and resulted in a thoracotomy for attempted surgical therapy. The fact that hemochromatosis represents the only cause of a restrictive cardiomyopathy that is potentially reversible by medical therapy makes early recognition of hemochromatosis heart disease important.

Characteristics of materials for intravascular application.

In the early part of t h i s century, there were many attempts to replace arterial segments with an extensive variety of materials, including glass, gold, silver, rubber and aluminum, as well as tubes lined with paraffin. Temporary patency was the usual result. Thrombosis occurred after varying short intervals. Between 1944 and 1946,l extensive work with the methyl methacrylate polymers in a lengthy series of experiments in dogs demonstrated that prostheses made of these materials under certain conditions tended to resist thrombosis. This was the first step toward the solution of the problem of arterial replacement, and the principles made possible the concept of intracardiac prostheses. These early studies showed that there was an interrelationship between the physical, chemical and electric properties of the blood-plastic interface and clot formation. At that time, certain factors were already shown by these studies to decrease the incidence of thrombosis in experimental arterial replacement. The first of these favorable characteristics was a hemorepellant surface, which was an extension of an older observation that blood in paraffin-lined tubes had a much longer clotting time than those in plain glass tubes. Second, a lack of water absorption was an additional property which related to the first. It was noted that those plastics which tended to have high water absorption had a high incidence of clot formation. Third, a lack of toxic plasticizers and stabilizers. Fourth, total polymerization of the plastic without residual monomer or catalysts. Fifth, the lack of leeching of toxic materials. Sixth, a mechanical smoothness of the surface of the material in the prosthetic biologic interface. And finally, seventh, a high degree of biologic tolerance by the host to the implanted material. When implants are placed into the arterial tree, the prevention of the production of an injury tissue potential in the region of the junction of the prosthesis with the adjacent tissue is an important factor in the prevention of thrombosis. These relatively simple principles were well delineated in this work. As a result, there has been general agreement that it is highly desirable to have these characteristics in any blood interface when blood must be brought into contact with a nonendothelial surface either inside or outside the body. This has been practically applied in plastic blood bags, the artificial kidney, and all phases of extracorporeal circulation. When materials must be employed which do not in themselves have these characteristics, it has been found that coating of the material in such a way as to bring about such desirable properties improves the performance. The use of silicone compounds to coat certain metallic surfaces is an example of this. The development of intracardiac devices of varying design for valvular replacement has evolved from these basic principles. The first of these devices was the ball-valve, first clinically .used in 1952* (FIGURE 1). It introduced, for the first time, the concept that a device made entirely of plastic materials could be permanently implanted into the cardiovascular system, be activated by the force

Iliac-caval arteriovenous fistula following operation for herniated disc.

From the Department of Surgery, Georgetown University Medical Center, Washington, D. C. * Professor of Surgery, Georgetown University Medical School. t Clinical Associate Professor of Medicine, Georgetown University Medical School. ‡ Instructor of Surgery, Georgetown University Medical School. Abdominal arteriovenous fistulas are not commonly reported following major trauma. Its occurrence after disc surgery appears to have been

Direct Repair of Dissecting Aneurysms of the Aorta

The concept of direct repair of dissecting aneurysm of the aorta has been proposed. The complete repair of the dissection and concomitant repair of aortic insufficiency have been discussed.