Intramyocardial dissecting hematoma following myocardial infarction is an unusual form of subacute cardiac rupture that tends to develop along naturally occurring dissection planes between the spiral muscles of the ventricle. The diagnosis has commonly been made at surgery, postmortem examination, or by echocardiography. Most are associated with acute transmural inferior infarction. Few patients survive without surgical intervention. Fourteen cases have appeared in the literature. One additional case is described. Ten cases were treated medically with one survivor (10%). Five cases were treated surgically with five survivors. Surgical treatment of intramyocardial dissecting hematoma is preferable to medical treatment. Proper and timely diagnosis and prompt surgical treatment are necessary before complete myocardial rupture ensues. Diagnosis is facilitated through the use of two-dimensional echocardiography. Successful surgical management of this condition requires an appreciation of commonly associated pathoanatomical conditions, and the utilization of appropriate methods of repair in the presence of potential ventricular septal and ventricular free wall rupture.

Free fatty acid-induced massive erythrocyte crenation has been reported in patients undergoing extracorporeal circulation (EC), suggesting that the crenated cells impair microcirculatory flow and tissue oxygenation during and after the operation. Effect of albumin administration on erythrocyte crenation was examined in 18 patients undergoing coronary bypass operation: 9 patients were given 25 g and another 9 patients were given 50 g of human albumin as a part of the priming solution. Erythrocyte crenation was almost completely prevented in the patients given 50 g albumin. Crenated erythrocytes during EC were 3.6 +/- 2.3% (mean +/- SD) of all erythrocytes and 2.8 +/- 3.7% after EC. This was significantly lower than in patients without albumin administration (63.4 +/- 34.0% during EC and 28.6 +/- 33.3% after EC, n = 20). But the effect was less striking in the patients given 25 g albumin, 32.4 +/- 39.1% during and 28.3 +/- 40.8% after EC. Maintaining an adequate level of plasma albumin is important in preventing erythrocyte crenation during EC, improving microcirculatory flow in patients undergoing open heart surgery.

Gibbon's rotating cylinder could not be enlarged to oxygenate an animal larger than a cat. The spinning disc oxygenator, introduced in 1947, had the capacity to perfuse a dog and the potential to increase oxygenation capacity by addition of more discs. When centers began to do three to four open-heart operations per day, the disposable bubble oxygenator was more practical. Bubble size was optimized to decrease the flow of oxygen relative to the blood flow and reduce trauma to blood. The bubble oxygenator is the type most commonly used today. Use of deep hypothermia with whole blood at an esophageal temperature of 10 degrees C was initially complicated by brain damage due to aggregation of white blood corpuscles and platelets. The introduction of hemodilution permitted safe utilization of hypothermic perfusion. Perfusion of infants should not be carried out at hematocrit below 25 ml/100 m. Early membrane oxygenators used nonporous silicone, or modified silicone membranes. High priming volumes, high pressure drop and marginal gas transfer efficiency characterized these devices. Recent advances in membrane technology have spawned a new generation of membrane oxygenators utilizing microporous polypropylene. In these new oxygenators, with either microporous hollow fibers or sheet membrane, the gas transfer characteristics are far superior to those of types produced in the past. The hollow-fiber devices typically have larger surface areas and higher pressure drop than in the new state-of-the-art flat plate models. An evaluation of one of these new-generation membrane oxygenators gave optimal oxygen and carbon dioxide exchange at a gas flow of 1 l/min of 60% oxygen in air at 30 degrees C and 2 l/min of 80% oxygen in air at normal temperature and rewarming for an adult. Today, after almost 40 years of oxygenator development, these new membrane device can offer better platelet preservation and reduced blood trauma as compared with types developed in the past. The new membrane oxygenators are fast becoming the preferred choice for use in infants and in protracted perfusion.

The Björk-Shiley monostrut valve, with a modified surface, was implanted in mitral position in 72 goats. An unhurried technique of isolated sutures through the wafer-thin base of the completely excised mitral valve in the beating heart at normothermia gave consecutive long-term survival in the goats without anticoagulation--up to one year. From the first postoperative day the goats lived freely on a farm, and one gave birth to two kids 6 months after valve replacement. These tests have hitherto been successful, but further hemodynamic testing and studies of explants are necessary for decisions concerning the applicability of the modified Björk-Shiley monostrut valve.

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