Abstract

Introduction: Ectopic kidneys result from abnormal embryological ascent and are frequently associated with distorted anatomy, predisposing patients to nephrolithiasis and technical challenges during intervention. Fused ectopic kidneys represent an exceptionally rare variant in which altered pelvicalyceal orientation and ureteral curvature further complicate stone management. Retrograde intrarenal surgery (RIRS) has become a standard minimally invasive approach for renal calculi in normal anatomy. However, data regarding its application in fused ectopic kidneys remains scarce. We report successful RIRS guided stone clearance in a uniquely fused ectopic renal system without the use of a ureteral access sheath. Methods: A 29 year old male presented with lower abdominal pain and was initially evaluated with ultrasonography, followed by contrast-enhanced CT urography. Imaging demonstrated a fused ectopic kidney with the right pelvicalyceal system and ureter oriented anterolaterally and the left system posteromedially. Two right renalstonesmeasuring1.4cmand1.3cmwereidenti𿿿edwithpreserveddrainage. StagedRIRSwasperformedundergeneralanesthesiausinga exibleureteroscope and Holmium:YAG laser lithotripsy. Due to marked ureteric angulation, access sheath placement was not feasible. Irrigation and suction were achieved using a three-way extension tubing system. Laser settings ranged from 0.8–1.2 J at 5–10 Hz. Double-J stenting was performed following each session. Results: Complete stone clearance was achieved over two operative sessions without intraoperative complications. Postoperative recovery was uneventful, with discharge on postoperative day one after each procedure. The ureteral stent was removed 15 days following the second intervention, and follow-up imaging con𿿿rmedastone-freestatus. Conclusion: Fusedectopickidneyspresentsigni𿿿cantanatomical challengesfor renal stone management and have traditionally required invasive approaches. This case demonstrates that RIRS with laser lithotripsy can be performed safely and effectively even in complex ectopic fused renal anatomy, including situations where access sheath use is not possible. With careful preoperative planning andtechnicalexpertise,RIRSshouldbeconsideredaviable𿿿rst-lineminimally invasive option for nephrolithiasis in anomalous kidneys.

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