Causes of complicated course of patients in the near future postoperative period, undergoing Fontaine''s surgery in the modification of the extracardiac conduit after a previously performed bidirectional cavopulmonary anastomosis
Objective -revealing new predictors of complicated course in the immediate postoperative period among patients who underwent Fontaine's operation in the modification of the extracardiac conduit after a previously performed bidirectional cavopulmonary anastomosis. Material and methods. The basis of this study was made by materials of clinical observations of 12 patients, conducted in the nearest postoperative period after surgery on the open heart for the period from 2011 to 2016. All 12 patients in the near postoperative period suffered from severe transudation into the pleural and abdominal cavities. In connection with this, in 2 patients a procedure “take-down” was performed, and in 1 patient - a fenestration. The mean age of patients was 7.58 ± 0.85 years, the average height was 119.3 ± 7.92 cm, the average weight was 23.86 ± 4.35 kg. Female patients were 8, male - 4. The main nosological characteristics of the patients included several different diagnoses: a double distal vascular from the right ventricle (4 patients), tricuspid valve atresia (2 patients), a single ventricle (4 patients), transposition of the main vessels with right ventricular hypoplasia (1 patient), general form atrioventricular communication with pulmonary artery stenosis (1 patient). Initially, the mean pressure in the pulmonary artery was 14.8±1.46 mm Hg, and the total pulmonary resistance 1.89±0.07 units. Four patients underwent fenestration between the extracardiac conduit and the right atrium. All patients underwent EchoCG study in dynamics. According to ultrasound, the final diastolic volume of the functionally single ventricle and the final systolic volume of the functionally single ventricle, the ejection fraction of the functionally single ventricle, the impact volume were determined. To determine the parameters of central hemodynamics used the generally accepted formulas. During the study, 5 measurements, reflecting the parameters of central hemodynamics and changes in PaO<sub>2</sub>, SaO<sub>2</sub>, PvO<sub>2</sub>, SvO<sub>2</sub>, were performed. Results. Despite the fact that the level of CVP for 5 days ranged from 14.33 ± 0.96 to 15.33 ± 1.33 mm Hg the level of transudation from the pleural and abdominal cavities was extremely high and was in the range from 1241.67±267.59 to 2470.8±391.2 ml per day. In this case, the indexed final diastolic volume of the functionally single ventricle gradually decreased from 70.63±10.22 on the first day to 51.25±7.47 ml/m<sup>2 </sup>by the fifth day, and the indexed stroke volume of the functionally single ventricle decreased from 43.7±7.07 to 29.05±4.27 ml/m<sup>2</sup>. At the same time, the ejection fraction of the functionally single ventricle fluctuated within 56%. The level of PvO<sub>2 </sub>was high for all 5 days and ranged from 45.58±1.76 to 49.92±2.16 mm Hg, and the value of SvO<sub>2 </sub>varied from 75.83±1.91 to 80.0±2.45%. The oxygenation index was low and ranged from 113.83±13.4 on the third day to 119.25±14.41 on the fifth day. Conclusion. Obviously, in our patients, a sharp decrease in the capacity of pulmonary veins due to their anatomical features led to the fact that the blood is always in the venous sector, preload of the arterial sector is sharply affected. Therefore, these patients are characterized by significant transudation into the pleural cavity, abdominal cavity, with a high fraction of the ejection of the “left” parts of the heart that suffer from a significant blood deficit as preload. All this is combined with tachycardia and low blood pressure, which can not be maintained at the proper level, despite the high doses of vasopressors (noradrenaline, dopamine). In patients with reduced capacity of pulmonary veins PO<sub>2 </sub>and SO<sub>2 </sub>in venous blood should be higher than in other patients due to a large discharge of oxygenated blood (passed through the pulmonary capillaries) through the kavakaval anastomoses to the system of inferior vena cava, that was also