The aim of the PhD thesis was reducing mortality and improving the quality of patients’ lives with complex congenital heart disease with single ventricle physiology and right ventricular hypoplasia by studying the immediate and long-term results after performing a bidirectional cavapulmonary anastomosis as a stage of hemodynamic correction by improving methods of diagnostics and surgical correction, substantiating the tactics and management of patients in the postoperative period
The thesis contains a theoretical substantiation and practical solution to an urgent scientific problem in the field of medicine - surgical treatment of patients with a functionally single ventricle of the heart and right ventricular hypoplasia.
The dissertation analyzes the diagnosis, surgical treatment and results of the study in 174 patients, who underwent bidirectional cavapulmonary anastomosis as an intermediate stage of hemodynamic correction from January 1996 to December 2022 at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine, Kyiv.
The median age of patients at the time of surgery was 35 months. [3; 420]. The median body weight of patients was 13 kg [5.3; 65]. The median body surface area was 0.23 m2 [0.29; 1.8]. Twenty-seven (15.5%) children were born prematurely at 31-36 weeks of gestation. A preliminary diagnosis was made prenatally in 57 (32.8%) patients, and in the other 117 (67.2%) just after birth by echocardiographic examination. Some patients (4% (n=7) were older than 16 years (GUCH), with a median age at the time of surgery of 300 [192; 420] months.
For comparative analysis, all patients were divided into groups depending on age at the time of surgery, anatomical and hemodynamic features of heart disease, and surgical treatment tactics. The contribution of the blood flow from the superior vena cava system to the systemic blood flow changes during the child's growth. In newborns and infants, it accounts for 49% of the circulating blood volume, in children during early childhood (1 to 3 years) it reaches 55%, and with the growth of the child it decreases and reaches 35% in the period of first childhood (4 to 7 years), so for a comparative analysis, patients were divided into three groups depending on their age at the time of surgery. The first group included 39 (22.4%) patients under the age of one year. The second group consisted of 69 (39.6%) patients who were operated on at the age of 12 to 36 months. The third group included 66 (38%) patients, who were operated on at the age of more than 3 years.
To select the optimal surgical treatment tactics, patients were divided according to anatomical and hemodynamic features. Among all (n = 174) patients in the main group, 94 (54%) patients were routinely operated on only by the univentricular Fontan hemodynamic strategy, the other 80 (46%) patients with borderline morphology of the right heart were operated on by two routes, so these patients were divided into two groups depending on the chosen surgical treatment tactics: Group A - 57 (71.2%) patients in whom the bidirectional cavapulmonary anastomosis was used as a staged partial Fontan hemodynamic strategy, Group B - 23 (28.8%) patients, who chose the one and a half ventricle pathway of hemodynamic correction, where the bidirectional cavapulmonary anastomosis performed the function of reducing the volume load on the hypoplastic right ventricle after the elimination of intracardiac heart anomalies.
The overall mortality rate for the entire study group was 6.9% (12 patients). In-hospital mortality was 4% (7 patients) and in the long-term period - 2.9% (5 patients). An uncomplicated course of the early postoperative period was observed in 133 (76.5%) patients. Other 41 (23.5%) patients of all groups: Group I 14 (8%) patients - 19 complications, Group II 11 (6.3%) patients - 14 complications, Group III 16 (9.2%) patients - 23 complications, respectively, by groups, which were explained by the severity of the preoperative condition of patients, specific changes in blood circulation, which are characteristic of a bidirectional cavapulmonary anastomosis.
The survival rate of patients who underwent the stage of bidirectional cavapulmonary anastomosis (n = 167) was: after 6 months - 98.8%, after 12 months - 97% and remained stable until the final stage of hemodynamic correction. The observation period lasted from 6 months to 180 months, 156 patients were observed, 96.2% of the number of patients who survived the surgical stage of the bidirectional cavapulmonary anastomosis. Communication was lost with 6 (3.7%) patients.
Peculiarities of morphology and hemodynamics of the single ventricle, severity of the preoperative condition, mean pressure in the pulmonary artery > 15 mm Hg, longer duration of surgery and cardiopulmonary bypass, low preoperative blood oxygen saturation, acute cardiac and respiratory failure requiring prolonged sympathomimetic support
