Endoscopic Combined Intrarenal Surgery for a Large Stone in a Rare Fused Supernumerary Kidney

A supernumerary kidney is a rare birth defect where an extra kidney is present. This extra kidney has its own separate outer covering, blood supply, and collection system. Normally, percutaneous nephrolithotomy (PCNL) is the treatment of choice for large kidney stones, but its ideal use for supernumerary kidneys is unknown. This report aims to show the success of a surgical technique called endoscopic combined intrarenal surgery (ECIRS) for removing a big stone from the fused supernumerary kidney of a patient. A 48-year-old man experienced occasional mild chronic pain in his left flank and occasionally hematuria. An imaging scan showed a stone (2.5 cm, 924 Hounsfield units) in a fused supernumerary kidney on the left side. The stone was successfully removed with a single procedure of PCNL that consisted of PCNL and a retrograde ureteroscopy approach at the same surgical time. ECIRS management of urinary tract calculi can be a consideration for patients presenting with fused supernumerary kidney and large stone, offering a reasonable success rate.