Biomedical subjects
Publications and source records attributed to C A Hufnagel.
The patients at high risk of deep venous thrombosis are defined. Factors in the formation of intravenous thrombi are described. The roles of endothelium, formed elements, clotting factors, and their interrelationships are correlated. Diagnostic modalities and their application are described, and the commonly used medical and surgical therapies are specifically outlined.
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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.
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A new technique of computed tomography (CT) applied to the diagnosis of abdominal aortic aneurysms is described, and the experience in 58 patients is reviewed. In all instances the abdominal aorta was clearly demonstrated, even when wall calcification was absent. A series of 37 patients with abdominal aortic aneurysm underwent evaluation by physical examination, abdominal roentgenograms, and ultrasonic and CT scanning. Measurements of the transverse diameter at the point of maximal dilatation were compared with the measurements made at operation. CT not only confirmed the diagnosis in all patients but the measurements obtained by this technique were the most accurate, correlating extremely well with the true dimensions of the aneurysm. The addition of contrast enhancement to CT scanning allowed clear delineation of the aortic lumen and intraaneurysmal thrombus, not possible with any other method, including ultrasonography. The technique appears useful as a screening procedure and in the differential diagnosis of a tortuous abdominal aorta. Patients with a small aortic dilatation can be followed accurately by scanning.
Clinical and morphologic features are described in a 56-year-old man in whom severe, isolated pulmonic valve stenosis was treated by valve replacement with a porcine prosthesis. The calcific deposits were located on the ventricular aspect of the pulmonic valve, opposite the location (arterial aspect) of calcific deposits on stenotic aortic valves, and calcific deposits also were present in the tricuspid valve anulus.
Serial determinations of serum lactate dehydrogenase (LD) isoenzymes were performed in 50 patients undergoing cardiac surgery for coronary artery bypass and heart valve replacement. A sequence of LD isoenzyme patterns was established in the patients with uncomplicated recovery. These patterns served as controls for the detection of abnormal patterns associated with clinical complications. Perioperative myocardial infarction was detected in seven patients by a characteristic reversal of the LD1:LD2 ratio. These studies established that accurate determination of LD isoenzymes improved their diagnostic specificity. These isoenzymes were determined by (1) using the same technique for tissues and for serum samples, (2) applying a volume of serum containing a standard amount of enzymatic activity, and (3) making a clear separation, which allows accurate quantitation. This test can provide useful information to the surgeon for the evaluation of operative procedures and to the clinician for the appropriate management of the patient undergoing cardiac surgery.
Clinical and morphologic features are described in two relatively young adults with aortic regurgitation secondary to chronic aortitis. The regurgitation in each was severe enough to require aortic valve replacement. Both patients had normochromic, normocytic anemia, considerable weight loss despite congestive cardiac failure, and negative serologic tests for syphilis. These systemic manifestations in association with the aortitis suggest that both had Takayasu's arteritis. In addition, one patient had total occlusion at the origin of one subclavian artery (classic pulseless disease). Takayasu's arteritis must be added to the list of causes of severe aortic regurgitation.
Clincal and hemodynamic observations are reported in a group of five patients with free aortic regurgitation treated with insertion of a ball valve prosthesis in the descending aorta. Long-term follow-up ranging from 13 to 23 years illustrates the durability and biocompatibility of the valve and the validity of the concept that a moving prosthesis can function for indefinitely long periods of time. The prolonged survival of these patients at a normal level of activity without congestive failure is strong evidence of the efficacy of the prosthesis even though it did not entirely control all of the aortic insufficiency. All patients showed remarkable improvement of their symptoms from 11 to 21 years after surgery. Four of them have required complete correction of the aortic insufficiency with one postoperative death due to low output syndrome. The valves which have remained in place after insertion of a subcoronary valve are functioning well for 3 to 6 years. There was no evidence of hemolysis, valve malfunction, ball variance, or thrombbosis in any of these patients. The evolution of the technique made it possible to minimize complications which, it should be pointed out, were usually associated with faulty methods of insertion. These patients would appear to represent the longest period of insertion of any valvular prosthesis.
Necropsy observations are described in 20 patients dying between October 1967 and March 1973 after replacement of the aortic valve with a Hufnagel trileaflet prosthesis. Seven patients died within two months of operation and 13, between 2.1 and 58 months (average 22). Four of seven patients dying early had extensive prosthetic thrombus causing obstruction of one coronary arterial ostium in each. Of the 12 patients surviving six months or longer after valve replacement, death in eight resulted from degeneration (tearing) of the prosthetic cusps causing severe aortic regurgitation in each, and from thrombosis of the prostheses in three, probably causing prosthetic stenosis and defintely causing narrowing of at least one coronary ostium. Thus, prosthetic degeneration or thrombosis caused death in 11 of the 12 patients surviving six months or longer. In conclusion, this trileaflet aortic prosthesis, although similar in design to the normal aortic valve, is composed of materials not durable enough to withstand the stresses created by blood flow in this position.
A rare case of large intrapericardial bronchogenic cyst with superior vena caval obstruction is reported. The cyst was successfully removed and the superior vena cava, which was narrowed by pressure fibrosis and thrombosis, was reconstructed satisfactorily and has maintained patency. In another case a large cyst of the same type without vena caval obstruction was successfully treated surgically. The features of these 2 cases are compared with those of 20 reported cases. The angiographic data in these cases appear to be sufficiently characteristic to suggest the nature of the lesion and the clinical finding of pericarditis early in the course of the disease may also suggest the diagnosis.
A review of the literature shows an increaseing number of cases of superior vena cava obstruction associated with malignancy and a marked decrease in the number of patients with caval obstruction of benign origin. In contrast to granulomatous diseases and aneurysms of the ascending thoracic aorta, which have decreased, the incidence of benign tumors is essentially unchanged. Clinical features of superior vena cava obstruction in relation to the anatomical site of obstruction and collateral pathways are correlated. Diagnostic approaches, including angiography and technetium scanning are usually definitive in outlining the site of obstruction. Experimental data and the numerous available techniques for surgical correction indicate that an entirely satisfactory procedure is not available for all patients. Methods include the use of venous bypass or Teflon prostheses and the addition of a small arteriovenous fistula proximally. Two new cases of superior caval obstruction due to benign tumor are reported. In 1 patient, who had intrapericardial bronchogenic cyst with fibrotic caval obstruction and thrombosis, a method for caval reconstruction while maintaining venous return to the right atrium is described. The second patient had an intrathoracic thyroid adenoma and caval obstruction without thrombosis.
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