(P 298) RESECTION OF PARA-RENAL INFERIOR VENA CAVA LEIOMYOSARCOMA WITH RIGHT NEPHRECTOMY AND LEFT RENAL VEIN LIGATION WITHOUT VENOUS RECONSTRUCTION.

Objective: Leiomyosarcomas (LMS) of the inferior vena cava (IVC) often require segmental vascular resection. When both renal pedicles are involved in the tumour, enbloc right nephrectomy and left renal vein (LRV) ligation may be necessary to achieve negative margins. Whether LRV reconstruction is required in this context remains unclear. This study evaluates perioperative renal outcomes and safety following IVC resection, right nephrectomy, and LRV ligation without reconstruction in LMS.

Methods: A retrospective review of patients undergoing IVC LMS resection between 2010 – 2024 at a high-volume sarcoma unit.

Results: 46 patients underwent IVC resection for LMS; 20 (43 %) had IVC reconstruction with graft, 26 (57 %) had ligation of the IVC without reconstruction. Among them, 18 (39%) required both right nephrectomy and LRV ligation without reconstruction.
The overall complication rate (Clavien-Dindo ≥3) was 19% (9/46), with median length of stay (LOS) of 13 days. In the LRV ligation subgroup, complication rate was 33%, median LOS 13 days.
Of the 18 patients with LRV ligation, 14 (78%) had either no renal dysfunction n=4 (22%), or transient impairment managed conservatively n=10 (56%). In these 14 patients, serum creatinine peaked on postoperative day (POD) 2 (mean 169 µmol/L) and decreased significantly by POD10 (mean 122 µmol/L) consistent with recovery of renal function. 4 (22%) patients required short-term hemofiltration starting POD 1-3 with median duration of 7 days. Further improvement in renal function was seen at 1-month follow up confirming the reversible nature of the renal impairment. No patient required long-term dialysis (Table 1).
No significant difference in OS (p=0.349) and DFS (p=0.233) was found between patients with or without LRV reconstruction.

Conclusion: LRV ligation without reconstruction, even when combined with right nephrectomy, is safe and well-tolerated in patients undergoing IVC LMS resection. Most patients develop sufficient venous collaterals, and renal dysfunction is mild, reversible, and not associated with adverse oncologic outcomes.

Mean serum creatinine (µmol/L) after surgery for LMS IVC with right nephrectomy and LVR ligation in patients with vs. without postoperative hemofiltration