Three-dimensional Models for Individualized Preoperative Planning of Robot-assisted Partial Nephrectomy in Patients with Horseshoe Kidneys: A European Multicenter Case Series (YAU RCC-UroCCR).

Renal tumors in horseshoe kidneys (HSKs) present unique surgical challenges because of complex vascular anatomy, limited organ mobility, and the proximity of critical structures. We report a European multicenter case series of 24 patients with HSK tumors who underwent robot-assisted partial nephrectomy that was planned with patient-specific three-dimensional (3D) virtual models. Reconstructions were generated from multiphase computed tomography scans, which allowed detailed vascular mapping and tailored ischemia strategies. The median tumor size was 5.4 cm, with a median of three renal arteries per patient. A clampless approach was achieved in 12 cases (50%), including five with anatomic devascularization via ligation of tumor-specific segmental arteries. When clamping was required (n = 12), the median warm ischemia time was 23 min. There were no conversions to open surgery and no local recurrences. Major complications occurred in two patients (8.3%) and the median decline in estimated glomerular filtration rate was -5.0 ml/min/1.73 m2 at last follow-up. Trifecta outcomes (negative surgical margin, no major complications, and renal function ≥90% of the baseline value) were achieved in 50% of cases. This series highlights the role of 3D surgical planning in optimizing vascular control, facilitating nephron-sparing techniques, and preserving renal function in these anatomically highly complex procedures.