Investigation of whether renal tumours with caval thrombi induce particular risks: a multicentre study (UroCCR‐174 CAVORISK)

Objective To compare outcomes of nephrectomy for left‐sided ( n  = 70) vs right‐sided ( n  = 118) renal tumours with caval thrombi. Methods In this retrospective analysis (June 2008–February 2023), we evaluated peri‐operative variables, 30‐day complications, estimated glomerular filtration rate (eGFR), and survival rates. Results Patients in the left‐sided renal tumour group experienced significantly longer operating times (240 vs 193 min; P  < 0.001), greater blood loss (1700 vs 1000 mL, P  = 0.042), and more complications (53% vs 35%, P  = 0.015). Postoperative renal function was worse in the left‐sided vs the right‐sided renal tumour group, with lower immediate postoperative eGFR ( P  = 0.035) and a higher dialysis rate (17% vs 6.8%, P  = 0.026). However, overall survival and recurrence‐free survival were similar ( P  = 0.8 and P  = 0.43, respectively). Conclusions Left‐sided renal tumours with caval thrombi present a higher risk of complications and acute kidney injury requiring dialysis, potentially due to left renal vein ischaemia during surgery and anatomical proximity to the superior mesenteric artery. Thorough preoperative planning and limited clamping time are essential.