V3-01: Technical considerations for a horseshoe kidney and a posteriorly occurring renal mass: The use of intravenous indocyanine green and 4th arm in robot-assisted partial nephrectomy
Horseshoe kidney is a congenital anomaly in which the fused kidneys fail to ascend to their normal position. Anatomic aberrations including renal malrotation and the presence of an isthmus can make access to the posterior renal anatomy challenging. Persistent embryonic arteries combined with variations in origin, number, and size of renal arteries contribute to the increased potential of excess blood loss during surgery. Taken together, these anatomic variations make minimally invasive surgery in horseshoe kidneys technically challenging. Although minimally invasive techniques have been utilized for partial nephrectomy (PN) in horseshoe kidneys, reporting on technical modifications during robot-assisted techniques is minimal. Here, we present a case of a renal mass located in a horseshoe kidney and describe our technique for robot-assisted PN in this patient population.
A 65-year-old female presented with an incidental finding of a 5.6 cm posteriorly occurring enhancing renal mass on the left lower pole of her previously undiagnosed horseshoe kidney. Workup included a CT angiogram for further evaluation of renal vasculature. Nephrometry score was 2+1+3+P+2= 8-P-H. The left moiety was fed by two renal arteries with significant distance between them, and a single renal vein inserting more distally into the inferior vena cava. The patient ultimately opted for robot-assisted PN. A fourth arm Grasping Retractor was utilized early for improved hilar retraction, and later for folding the kidney on its isthmus to create posterior access and optimal exposure during tumor enucleation. Intravenous indocyanine green (ICG) instillation was used in conjunction with near infrared fluorescence to attempt selective arterial clamping and improve intraoperative understanding of renal perfusion as well as the renal mass.
Console time was 157 minutes with an estimated blood loss of 300 mL. Warm ischemia time was 19 minutes. The patient was discharged on post-operative day one. There were no perioperative complications. Pathology revealed a 5.7 cm oncocytoma.
We demonstrate that using ICG and the 4th arm are technical considerations that can assist with robot-assisted PN in a horseshoe kidney, especially for posteriorly occurring tumors.