Intraoperative Thrombus Embolization During Nephrectomy and Tumor Thrombectomy: Critical Analysis of the University of California-Los Angeles Experience

Purpose: Vascular invasion commonly occurs in renal cell carcinoma and intraoperative thrombus embolization is a known complication of tumor thrombectomy. We reviewed our experience with this complication to determine frequency, mortality, common factors and management strategies. Materials and Methods: We retrospectively reviewed a prospective database of cases of open nephrectomy/tumor thrombectomy performed from 1989 to 2008. All cases were reviewed to identify clinicopathological variables, the thrombus extent and intraoperative complications. All cases with events were reviewed to identify preoperative pulmonary embolism, preoperative imaging, thrombus extent, presentation, management and outcome. Results: A total of 282 cases of venous tumor thrombus were identified. Tumor thrombus level was 0 in 133 cases (47.2%), I to II in 85 (30.1%), III in 27 (9.6%) and IV in 29 (10.3%). Thrombus embolization was identified in 5 patients (1.8%). The incidence in level 0 vs I to IV was 0 of 133 cases (0%) vs 5 of 149 (3.4%), which was statistically significant (p = 0.04). Three patients (60%) died of the event. A review of recent series demonstrated a 1.49% incidence with 75% mortality. Conclusions: Intraoperative thrombus embolization is rare but when it occurs, mortality is extremely high. Strict attention to surgical principles is necessary to decrease risk. Extension into the vena cava, preoperative pulmonary embolism and a bland thrombus component may indicate increased risk. Adjunct procedures, such as preoperative filters and endoluminal occlusive balloons, may be justified in patients at high risk. Even with prompt recognition and embolectomy survival is rare.