Defining a threshold for safe surgical management of vena cava thrombus in renal cell carcinoma patients: evidence from German total population data with 3,700 cases from 2006 to 2020

The management of inferior vena cava (IVC) tumor thrombus in patients with renal cell carcinoma (RCC) is among the most challenging surgical procedures. We aimed to define a minimum annual caseload for sufficient expertise.

We identified all cases with RCC, nephrectomy, and IVC procedures in the Federal Statistical Office billing database (2006–2020). We defined annual hospital caseload categories as low (< 4 cases), medium (4–9 cases) and high (> 9 cases) volume. Logistic multivariate models identified mortality-related factors. In addition, we analyzed data on tumor stage distribution from German cancer registries.

We recorded 3,700 nephrectomies with IVC-tumor resection with stable annual case number of 247 mean. This correlated with a stable incidence of T3b/c RCC. Patient age was 66 ± 14 years. Of all cases, 56% occurred in low, 30% in medium, and 14% in high volume clinics without a significant trend towards centralization. The overall in-hospital mortality rate was 5.8% and the transfusion rate 72%. An annual caseload of 8 showed to be a significant cut-off for mortality with 6.2% at < 8 cases and 2.8% for > = 8 cases annually (p < 0.001). Multivariate analysis revealed patient age (OR 6.4 for octogenerians) ventilation time (OR 14.3 for > 24 h) and hospital caseload (OR 2.6) as the most important risk factors for in-hospital mortality.

Our results show a negative correlation of annual caseload and mortality for this procedure. A minimum number of 8 procedures per year seems reasonable for the successful management of IVC tumor thrombus with significantly lower mortality.