Table 6.

Stone management in HSK.

Study	Characteristics	Procedure/results	Conclusion
Chen (2019) 14	Aim  URS versus ESWL in HSK for stones less than 2 cm in size Study  Review, four retrospective studies	Patients  127 (HSK only) Stone size  Less than 2 cm Procedure  ESWL = 62, URS = 67 Complications  All studies reported no severe complications. However, renal colic episodes are more likely to occur in the SWL group	For a stone <2 cm in HSK, ESWL, and URS are both safe treatment modalities URS alone is a more feasible and sufficient option for stone in HSK than ESWL with the possibility of a second session
Kartal (2019) 15	Aim  URS versus PCNL in HSK Study  Retrospective	Patients  49 patients (41 males, 8 females) Stone size  22.3–24.5 mm Stone location  Pelvis: 15, calyx: 22, pelvis + calyx: 12 Procedure  PCNL = 21  URS = 28 Complications  CD grade 1–3, 14 patients  CD grade 4, 1 patient	Renal stones in the HSK anomaly can be treated with high rates of success using PCNL in a single session, and a similar success rate can be achieved by RIRS with acceptable re-treatment rates. Moreover, RIRS may be chosen to avoid complications associated with PCNL due to the minor character of the associated complications and its safe use on renal stones in the HSK anomaly

CD, Clavien–Dindo complications; ESWL, extracorporeal shock wave lithotripsy; HSK, horseshoe kidneys; PCNL, percutaneous nephrolithotomy; RIRS, retrograde intra-renal surgery; SFR, stone-free rate; URS, ureterorenoscopy.