Influence of the azygos venous pathway state on the surgical complexity of patients with renal cell carcinoma and inferior vena cava tumor thrombus: a retrospective, large-sample study from China

To investigate the heterogeneity of azygos-hemiazygos venous pathway (AVP) in renal cell carcinoma (RCC) with venous obstruction caused by tumor thrombus (VTT), and evaluate its relation to intraoperative hemorrhage and surgical complexity. Patients with RCC and VTT who underwent radical nephrectomy and tumor thrombectomy(RNTE) from January 2014 to March 2022 were included continuously in this retrospective study. The AVP was measured by maximum venous width at aortic hiatus level (MVW at AH level), and compared across various levels of venous obstruction. The correlation to intraoperative hemorrhage was assessed using Spearman’s rank correlation. Receiver Operating Characteristic curve analysis was conducted to evaluate the ‌associative‌ performance and patients with compensated AVP were defined according to the optimal threshold.Surgical and other clinical features were compared between patients with and without compensated AVP. Three hundred thirty-three patients were included. The heterogeneity of AVP was apparent, with MVW at AH level ranging from 0.9 to 19.1 mm, and correlated to venous obstruction(p < 0.01). Increased MVW at the AH level was strongly associated with more intraoperative hemorrhage (p < 0.001). The AUC value for the risk assessment of massive hemorrhage was approximately 0.82, with an optimal cutoff identified at 7 mm.106 patients were defined with compensated AVP, they had higher hemorrhage volume (p < 0.001), longer surgery time (p < 0.001), higher rates of conversion to open surgery and postoperative complications (p = 0.012, p < 0.001). AVP exhibits notable heterogeneity among patients with RCC and VTT, and may represent a promising potential indicator for surgical planning. RNTE carry a significant tendency of intraoperative bleeding, preoperative identification of patients at risk of massive hemorrhage aids the deployment of surgical strategy. Measuring the AVP with MVW at the AH level appears to be associated with the risk of massive hemorrhage (> 2000 ml), and the AUC for this cohort was found to be approximately 0.82.