Objective: to describe the technique of nephrectomy and thrombectomy used in patients with renal cell carcinoma (RCC) and tumor venous thrombosis of various levels, and to identify risk factors of in-hospital death among operated patients. Materials and methods. This study included 768 patients with RCC and tumor venous thrombosis who have undergone surgical treatment. Median age was 58 years (range: 16-82 years); the male to female ratio was 2.3:1. The symptoms of venous tumor thrombosis were identified in 199 patients (25.9 %). In the majority of patients (n = 509; 66.3 %), the tumor thrombus originated from the right renal vein. The cranial border of the tumor thrombus was located in the perirenal inferior vena cava (IVC) in 219 patients (28.5 %), subhepatic IVC in 201 patients (26.2 %), intrahepatic IVC in 171 patients (22.3 %), and above the diaphragm in 177 patients (23.0 %). We used an individual approach to choose an optimal method of vascular control and to identify indications for circulatory support. Two-thirds of patients (n = 512; 66.7 %) underwent temporary block of the second renal vein; 268 patients (34.9 %) - temporary block of the hepatoduodenal ligament and right heart; 11 patients (3.2 %) were operated on with cardiopulmonary bypass. Results. The median surgery time was 190 +/- 63.6 min; median blood loss was 3,000 +/- 71.6 mL (>= 50 % of circulating blood in 35.1 % of patients). Intraoperative complications were registered in 23 patients (3.0 %); eight patients (1.0 %) died during surgery with 4 of them died due to pulmonary embolism (0.5 %), 3 died due to hemorrhagic shock (0.4 %), and 1 died due to myocardial infarction (0.1 %). One hundred and ninety individuals (25.0 %) developed postoperative complications with Clavien-Dindo grade III-V complications observed in 115 cases (15.1 %). Forty-one patients (5.3 %) died in the early postoperative period. The causes of death included multiple organ dysfunction (n = 21; 2.8 %), pulmonary embolism (n = 7; 0.9 %), sepsis (n = 6; 0.8 %), stroke (n = 4; 0.5 %), myocardial infarction (n = 2; 0.2 %), and RCC progression (n = 1; 0.1 %). We have identified several independent risk factors for in-hospital mortality, including ascites (hazard ratio (HR) 8.3; 95 % confidence interval (CI) 3.2-21.4; p < 0.0001), preoperative pulmonary embolism (HR 3.5; 95 % CI 1.3-9.4; p = 0.013), supradiaphragmatic thrombi (HR 1.5; 95 % CI 1.1-2.0; p = 0.003). The in-hospital mortality rate was 3.5 % (20/575) among patients with no risk factors, 9.8 % (16/163) among those with 1 risk factor, 40.0 % (10/25) among those with 2 risk factors, and 60.0 % (3/5) among those with 3 risk factors (area under the curve (AUC) 0.705; p <0.0001 for all). Conclusion. The incidence of severe complications and postoperative mortality rate in RCC patients with tumor venous thrombosis who have undergone nephrectomy and thrombectomy were 15.1 and 6.4 %, respectively. Risk factors for perioperative mortality included ascites, preoperative pulmonary embolism, and supradiaphragmatic thrombosis.
