Long-term circulatory and respiratory support using two artificial ventricles and a fluorocarbon oxygenator.

Using a new heart-lung machine developed at our Institute, experiments were conducted on dogs, donkeys, and monkeys, providing complete and assisted artificial circulation, assisted oxygenation, and perfusion preservation of the heart. The new apparatus consists of two sequentially mounted artificial ventricles working in an antiphase mode; blood oxygenation is accomplished by a reusable oxygenator with a fluorocarbon preoxygenator. Experimental results indicate that clinical use of the apparatus is promising and deserves consideration. The conditions of perfusion were close to physiological conditions and provided long-term survival of the animals. Performance in left ventricular bypass was optimized by monitoring myocardial PO2 and the state of the quick-connect/cut-off assemblies.

Development of methods of assisted circulation with artificial heart ventricles.

A comparative study of two methods of bypassing the heart with artificial ventricles (AV) was conducted: left atrium-aorta and left ventricle-aorta. The following factors permit left ventricular bypass to compete successfully with left ventricle-aorta bypass: creation of perfected pumps with low input impedance, use of materials with high resistance to thrombus formation for preparation of the AV and main connecting lines, and development of optimum methods of anticoagulant, disaggregation, and cardiac therapy so that there is no danger of thrombosis and hemorrhage, either experimentally or clinically. Thrombosis was the primary cause of death in only one case in a series of experiments on 15 calves with AV connected according to the atrium-aorta scheme. The positive changes in hemodynamics were approximately the same with the two methods.

Improvement in intra-aortic balloon pumping and evaluation of its efficacy by electrode methods of control.

A basically new design for the reversing balloon pump has been proposed for increasing the efficacy of intra-aortic balloon pumping (IABP). The device not only causes a significant increase in discharge, but also permits control of the central and peripheral circulation within the desired limits owing to back-and-forth movements (like a piston) of the balloon pump. Standard one- and two-chamber balloon pumps were compared. In addition to traditional hemodynamic and biochemical indexes, the efficacy of IABP was assessed based on electrode monitor control of PO2 and pH in the myocardium, peripheral tissues, and circulating blood. Based on 54 experiments on dogs, it was found that IABP with reversing balloon pumps in synchronous pulsation resulted in survival of 69% of the cases; PO2 and pH levels in the myocardium, tissues, and blood in the coronary sinus were close to normal, and coronary blood flow and peripheral circulation were increased. With standard one-chamber balloon pumps, the survival rate did not exceed 33.4%; PO2 and pH in the peripheral tissues reached critical levels.

[Stomach and duodenal ulcer in chronic nonspecific lung diseases]. / Iazvy zheludka i dvenadtsatiperstnoi kishki pri khronicheskikh nespetsificheskikh zabolevaniiakh legkikh

The results of observations over 61 patients suffering pneumosclerosis and chronic lung emphysema, associated with secondary gastroduodenal ulcers, are reported. These made 20.2% among 302 patients with gastroduodenal hemorrhages. The clinic of these ulcers in a third of patients having cardiopulmonary insufficiency is characterized by few or no symptoms at all, that would handicap their diagnosis. For timely prevention of grave complications the authors recommend a careful examination of the gastrointestinal tract in all patients with persistant chronic lung affections, who complain of abdominal pains and dyspepsia.