Table 2.

RIRS/ureteroscopy in anomalous kidney stone management.

Study	Characteristics	Procedure/results	Conclusion
Garcia (2021) 6	Aim  To analyze the trends and outcomes of RIRS (retrograde intrarenal surgery) for the treatment of urolithiasis in anomalous kidneys in a large international multicenter series. Study  Retrospective-multicentric	Patients  414, males = 227, females = 137  HSK = 119, EK = 102, MRK = 69, Diverticular calculus = 50 Stone characteristics  Size Avg. 13.9 mm (±6) Procedure  In 249 cases (60.14%), a disposable scope was used, and a reusable scope in 165 (39.85%) cases  A preoperative stent was reported in 46.6%  UAS was used in 90% of cases  Holmium: Yttrium-almuniuim-garnet laser was used in 391 (94.4%) patients and a thulium fiber laser in 23 (5.6%)  The mean operative time was 65.3 min  Post-op stenting was performed in 392 (94.7%) patients  Our series had a single-stage SFR of 79.2% Complications  Hematuria (10.9%), upper urinary tract perforation, or a ureteral injury 1.9% and 1.7%, respectively  Surgery abandonment in 4.3%	RIRS in patients with anomalous kidneys is a safe and effective treatment with an acceptable complication rate in experienced hands. The SFR is expected to be high when careful case selection is made and when patients are treated in high-volume centers with experienced surgeons
Lavan (2019) 7	Aim  Role of ureteroscopy in the management of stones in anomalous kidneys Study  Systemic review  14 Studies, 13 retrospectives, 1 prospective	Patients  413 (30.5) had a previous endourological procedure  HSK = 204, EK = 117, MRK = 86, CFRE = 2, Others = 4 Stone characteristics  Size Avg. 16 mm  Stone location (lower pole 34.6%, pelvic 31%, multiple locations 18.9%) Procedure  Ureteroscopies only  Flexible URS was used in 90% of cases  A preoperative stent was reported in 26.4%  UAS was reported in 11 studies  Holmium laser was used in 12 out of 13 studies  The mean operative time was 61.3 min (range: 14–185 min)  Post-op stenting was done in all patients in 6 studies in others it was variable (46.2–84%)  The initial and final SFR was 76.6% (n = 322) and 82.3% (n = 340), respectively  Overall, 71 (17.2%) Complications  Complications were reported of which 61 (14.8%) were Clavien–Dindo ⩽ II, and 10 (2.4%) were Clavien–Dindo ⩾ III	Ureteroscopy in patients with anomalous kidneys can be technically challenging, advancements in endourological techniques have made it a safe and effective procedure. In these patients, the stone-free rates are good with a low risk of major complications
Ugurlu (2014) 8	Aim  Ureteroscopy in the management of anomalous kidney stones Study  Retrospective	Patients  25 (17 males, 8 females)  Lumbar ectopic: 7, pelvic ectopic: 6, HSK: 3, mal-rotated kidney: 4, CFRE: 1, Others: 4 Stone characteristics  Size 194.4 mm2  Location (lower calyx 14, middle calyx 4, upper calyx 7, pelvis 7) Procedure  RIRS with holmium laser Complications  Renal colic/urosepsis/pyelonephritis (1 each case)	F-URS with holmium laser lithotripsy is a very effective therapy for most stones in anomalous kidneys due to its less invasive nature, repeatable applicability, and acceptable complication rates

CFRE, crossed fused renal ectopia; EK, ectopic kidney; ESWL, extracorporeal shock wave lithotripsy; HSK, horseshoe kidneys; MRK, Mal-rotated kidneys; RIRS, retrograde intra-renal surgery; UAS, ureteral access sheath; URS, ureterorenoscopy.