Biomedical subjects
Publications and source records attributed to E V Len'ko.
The authors have made an analysis of 1500 operations using a unique technology of closure without perfusion of the interventricular septum defects of the heart under conditions of hypothermia. Lethality was 1.7%, frequency of recanalization of the defects was 0.9%.
The methods for reducing the blood loss by means of enhancing the effectiveness of the technique of surgical hemostasis of a thoracic wall wound--the main source of blood loss in operations on "dry" heart under conditions of perfusion-free hypothermia (27-26 degrees C) are considered. Minimal traumatization of the soft tissues of the thoracic wall and adhesions during thoracotomy performance and early wound closure with simultaneous warming of a patient contributes to 2-3 fold reduction in blood loss and shortening of the time of operation by 40-60 min.
The authors conducted a retrospective analysis of the case records of 757 patients who underwent correction of acquired heart valvular disease under conditions of hypothermia without perfusion. Intrapleural hemorrhage occurred in the postoperative period in 43 (5.7%) patients, in 35 of them rethoracotomy had to be performed to arrest the bleeding. In patients with aortal valvular diseases a relation was revealed between the postoperative blood loss and the patient's age, the volume of operative blood loss (reverse correlation), and total dose of protamine sulfate (direct correlation), in patients with mitral valvular diseases the postoperative blood loss was related to the volume of diuresis in the first postoperative day (direct correlation). It is concluded that defective surgical hemostasis is the main cause of intrapleural hemorrhages after correction of acquired valvular diseases of the heart under conditions of hypothermia without perfusion.
Correction of the acquired defect of the mitral valve was performed in 89 patients on the open heart under conditions of nonperfusion hypothermia. Roentgenological assessment of the lung state was used in the postoperative period. Typical morphofunctional alterations were detected after operations under conditions of nonperfusion hypothermia. It was found that the increased volume of +blood transfusions more than 19 ml/kg of the patient's body weight was followed by a reliably increased frequency and degree of ++roentgenological symptoms of injuries of the lungs.
The work analyzes causes of high blood loss in operations under conditions of nonperfusion deep hypothermia. It was found to be related with the division of massive adhesions in the preocclusive period and with the presence of prolonged heparinemia after occlusion. A combination of a minimal trauma of adhesions, reliable surgical hemostasis, early suturing the wound of the chest and early neutralization of activity of heparin allowed the operation blood loss to be 2.4 times less and the postoperative blood loss--2.7 times less.
Under analysis was the influence of two factors--blood loss (intraoperative and postoperative) and blood substitution--upon the frequency of postoperative complications in patients with acquired mitral heart diseases operated upon under conditions of non-perfusion hypothermia. A conclusion is made that hemotransfusion during operations performed under conditions of "dry" heart and non-perfusion hypothermia should be performed but in anemia threatening by hemic hypoxia.
Based on an examination of 100 patients with acquired heart diseases operated upon under conditions of nonperfusion hypothermia (28-24 degrees C) the authors have proved the key role of the square of the wound surface of the injury of the chest wall and traumatized (dissected) adhesions as well as time of circulation of heparin in blood at the stages of nonperfusion heating facilitating increased blood loss.
Blood transfusions were not performed intra- or postoperatively in 10 patients operated on for acquired heart valve defects under perfusion-free hypothermia (PFH). The otherwise favourable postoperative period was characterized by a moderate decrease in hemoglobin level and red blood cell count. No complications have been observed. It has been concluded that the volume of the blood transfused can be considerably reduced or in some cases there can be no transfusions at all during surgery under PFH.
The analysis of blood loss in profound perfusion-free hypothermia has shown that its main cause is that heparin neutralization was performed only after the warming of a patient to 34-35 degrees C. The results of in vitro studies have shown that heparin was effectively neutralized by protamine sulfate at room temperature (20 degrees C). Using protamine sulfate, heparin neutralization was performed at 25-27 degrees C in 90 patients, which reduced blood loss by 10-15% of the circulating blood volume and made it possible to avoid hemotransfusions in the post-operative period.