Renal Cell Carcinoma with Infradiaphragmatic IVC Tumour Thrombus: Prognostic Value of the Mayo Classification

To assess the differences in perioperative outcomes, surgical complexity, and long-term survival for patients with renal cell carcinoma and tumour thrombus extension into the infradiaphragmatic portion of the inferior vena cava, stratified by the Mayo Clinic classification levels I–III. This was a 10-year, single-institution retrospective case series of 33 consecutive RCC patients undergoing radical nephrectomy and IVC thrombectomy. Patients were stratified into Mayo levels I (n = 14), II (n = 13), and III (n = 6). Perioperative outcomes and survival were compared across the three levels. Increasing Mayo level was significantly associated with longer operative duration (p = 0.0159), and higher intraoperative blood loss (p = 0.0171). Postoperative morbidity (p = 0.0037) and mortality (p = 0.0394) also increased with higher levels. Survival analysis demonstrated significant differences among the groups, with median overall survival of 120.8 months for Mayo level I, 33.8 months for Mayo level II, and 7.7 months for Mayo level III. The Mayo Clinic classification of the infradiaphragmatic IVC thrombus (Levels I–III) correlates with increasing surgical complexity and decreasing survival. This subclassification of T3b renal cell carcinoma patients is crucial for guiding surgical strategy and predicting prognosis.