Robot-assisted surgical strategies for renal cell carcinoma (RCC) and inferior vena cava (IVC) thrombus (IVCT) (RCC-IVCT) based on thrombus height have been reported; however, the characteristics and techniques of IVCT with special morphologies have not been described. We aimed to develop a decision-making program for the morphological grouping of IVCT, report our initial series, and analyze the outcomes of a special group versus a common group.

From June 2013 to June 2023, 197 patients with RCC-IVCT underwent robot-assisted surgery based on morphological grouping, with a minimum 1-year follow-up. Data on clinicopathological, operative, and survival outcomes were collected and analyzed. Special morphologies including contralateral renal vein invasion or caudal IVC invasion, morphological grouping was mainly based on preoperative IVCT imaging characteristics. Detailed techniques were described for various morphological groups. In the group Banana, selective non-clamping of the contralateral renal vein was feasible. Regarding IVCT with a special morphology, for type a (bland thrombus), we prioritized protection of the collateral circulation of the IVC and contralateral renal function, for type b (tumor thrombus), we achieved complete tumor resection considering functional preservation.

Of 197 patients, 43 (21.8%) had a special morphology and 154 (78.2%) had a common morphology. Operative time (310 vs 230 min) and estimated blood loss (1200 vs 700 ml) were significantly greater for special morphologies (both p <0.005). Postoperative elevation in indicators of liver and kidney injury was transient in both groups. No significant advantages were noted for IVC artificial blood vessel replacement compared to IVC cavectomy. Patients with special morphological IVCT appeared to have poor overall and progression-free survivals.

The robot-assisted surgical strategy based on the decision-making program for morphological grouping contributed to a striking balance between tumor control and functional preservation, representing a minimally invasive approach for patients with special morphological IVCT.