Robert G. Carlson

Cystic Medial Necrosis of the Ascending Aorta in Relation to Age and Hypertension

The presence of cystic medial necrosis in the human ascending thoracic aorta was determined by histologic examination in a series of 250 necropsies. Cases of Marfans syndrome, idiopathic dilatation of the aorta and dissecting aneurysm were not included. The severity of lesions of cystic medial necrosis were graded on the basis of 1 to 4 according to the amount of basophilic ground substance and fragmentation of elastic tissue. In most positive cases the lesion was of minimal (grade 1 or 2) severity. The incidence of cystic medial necrosis increased progressively from 10 percent in the first two decades of age to 60 and 64 percent in the seventh and eighth decades, respectively. Using the Fisher probability test, this difference is highly significant (P < 0.01). Among hypertensive subjects, the incidence of cystic medial necrosis was consistently higher than in normotensive subjects of comparable ages. Using the chi square test by decades and “all together”, this difference could easily be due to chance alone (P = 0.36 → 0.94).

Partial anomalous pulmonary venous connections

Abstract Fifty-seven cases of partial anomalous pulmonary venous connections treated surgically at the University of Minnesota Medical Center are reviewed. There was no hospital nor late mortality. The electrocardiographic features seen in partial anomalous pulmonary venous connections are similar to those in isolated secundum type atrial defects and include right axis deviation, incomplete right bundle branch block and right ventricular hypertrophy. The roentgenologic features are also similar in these two conditions, with increase in the central and peripheral pulmonary vasculature, prominence of the hilar vessels and right ventricular enlargement. Occasionally the anomalously connected vessels may be visualized on planigrams or routine roentgenograms. Identification of anomalous pulmonary venous connections during right heart catheterization is frequently possible. This depends on the catheter entering a pulmonary vein from the venae cavae, increase in oxygen content in the venae cavae, angiocardiographic demonstration of the vein, or differential dye-dilution technics. Surgical correction of partial anomalous pulmonary venous connections directs the drainage from these veins through the atrial septal defect. A prosthetic patch is usually used for this purpose except in the rare instance of drainage into the infradiaphragmatic inferior vena cava. In the 6 patients without an atrial septal defect, a defect was created, and a prosthetic patch used to correct the drainage from the anomalous pulmonary venous connections in 5, and the sixth patient had the vein transposed to the left atrium (the scimitar defect).

Evolution of Corrective Surgery for Ebstein's Anomaly

Experience with eight cases admitted to the University of Minnesota Medical Center for surgical treatment of Ebsteins anomaly is presented. Correction by excision of the malformed and malpositioned tricuspid valve with prosthetic valve replacement is advocated as the procedure of choice. Some patients probably need a temporary avenue for right-to-left shunting at the atrial level until the atrialized right ventricle can achieve competence. None of the three patients with significant arrhythmias preoperatively has experienced this difficulty to date, after valve replacement.

Disposable Membrane Oxygenator Support During Emergency Coronary Angiography and During Surgery for Acute Myocardial Infarction or Chronic Myocardial Ischemia

Forty-two patients received successful total cardiopulmonary support with the effective, easy to use, completely disposable, Lande-Edwards Membrane Oxygenator.In 4 patients, partial cardiopulmonary support was provided with the Membrane Oxygenator and/or intra-aortic baloon pump during emergency coronary arteriography and corrective cardiac surgery for shock, following myocardial infarction.Two Lande—Edwards membrane oxygenators, 3 m2, were connected in parallel and joined in either a recirculation circuit or, more recently, a simplified gravity circuit. Three oxygenators were used for patients 80 kg to 103 kg body weight.Effective gas exchange was documented by the normal range of arterial and venous oxygen and carbon dioxide levels during flow rates of 50 cc/kg/min at 30°C. Safety of perfusion was demonstrated by 25 of 26 patients being discharged improved after complex aortocoronary artery by-pass graft operations. Minimal side effects were observed including plasma hemoglobin under 100 mg%, platelet c...

Myocardial revascularization: the effect of alteration of perfusion pressures upon myocardial implant blood flow.

Cardiovascular diseases are responsible for 54 per cent of the deaths in the United States. Myocardial infarction accounted for approximately 50 per cent of these fatalities.’ Extensive literature concerning attempts to revascularize the ischemic myocardium has appeared in the last decade, but determinants of myocardial implant patency have never been adequately defined. Immediate flow through arterial or venous implants has been considered an important factor in maintaining implant patency. 2, 3, 4, Other investigators doubted the existence of immediate implant blood flow and have suggested that the continual to and fro motion of blood within the implant is the important factor in maintaining the fluidity of blood within the lumen of the graft.6, &dquo;