INTRODUCTION: Horseshoe kidney is an uncommon congenital fusion anomaly that can make renal tumor surgery especially challenging because of altered rotation, limited mobility, variable vascular supply, and an unpredictable collecting system (1-7). This video presents a robot-assisted partial nephrectomy for a high-complexity renal tumor in this setting. CASE PRESENTATION: A 33-year-old man, with ECOG 0 and no relevant comorbidities, was diagnosed with a 7.5-cm solid renal mass in the central posterior portion of the left moiety of a horseshoe kidney. The lesion had a RENAL score of 10p. Contrast-enhanced computed tomography and three-dimensional reconstruction were used to understand the relationship between the tumor, aberrant vessels, renal hilum, and collecting system, supporting the decision to attempt nephron-sparing surgery (5, 8). Surgical technique and results: The procedure was performed through a transperitoneal robotic approach with the patient in right lateral decubitus using the Da Vinci Si platform. Port placement followed a standard renal robotic configuration, with a paramedian supraumbilical camera port, three robotic working ports along a craniocaudal lateral axis, a caudal fourth-arm port, and two medial assistant ports for suction, exposure, and support during renorrhaphy. After exposure of the horseshoe kidney and left hilar dissection, two arterial branches and one renal vein were identified. Tumor excision was performed under vascular control, with 20 minutes of warm ischemia and no collecting system opening, followed by two-layer absorbable renorrhaphy with adjunctive hemostatic agents. The operative time was 150 minutes. No transfusion, conversion, drain placement, or relevant immediate complication occurred. The urinary catheter was removed after 24 hours, and the patient was discharged 72 hours after surgery. Pathology showed clear cell renal cell carcinoma, Fuhrman grade 3, pT2N0M0, with negative surgical margins. During 12 months of oncologic follow-up, renal function remained stable and semiannual imaging showed no evidence of recurrence. Contemporary video reports have also emphasized the feasibility of advanced robotic renal surgery and complex partial nephrectomy strategies in selected patients (9, 10). CONCLUSION: In a carefully selected patient, robot-assisted partial nephrectomy supported by three-dimensional planning was feasible for a complex renal tumor in a horseshoe kidney, with negative surgical margins, preserved renal function, and no recurrence during 12 months of follow-up.
Tobias-Machado et al. (Fri,) studied this question.