Comparative evaluation of urolithiasis management options in patients with horseshoe kidney: a systematic review and meta-analysis

Background: Horseshoe kidney is a rare congenital anomaly commonly complicated by urolithiasis. Extracorporeal shockwave lithotripsy (ESWL), ureteroscopy (URS), and percutaneous nephrolithotomy (PCNL) are treatment options for horseshoe kidney stones. The aim of this systematic review is to compare the benefits and risks of these management options.

Methods: MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to February 2022. A total of 516 nonduplicate studies were screened against the inclusion and exclusion criteria. Studies comparing at least 2 interventions with ≥10 patients per intervention were included.

Results: Nine retrospective observational studies published from 2007 to 2021 with a total of 565 patients were included. Reported mean ± SD or mean (range) stone sizes ranged between 17.90 ± 2.43 mm and 27.9 ± 8.6 mm for PCNL, 8.4 (2-25) mm and 22.3 ± 9.1 mm for URS, and 11.9 ± 2.0 mm and 16.8 ± 4.4 mm for ESWL. There was no difference in single-session and overall stone-free rate (SFR) between PCNL and URS, with a risk ratio of 1.04 (95% confidence interval, 0.95-1.13; I2 = 20.63%). Ureteroscopy had better stone clearance than ESWL, with an overall SFR risk ratio of 1.38 (95% confidence interval, 1.04-1.82; I2 = 0%). There was no statistically significant difference in overall SFR between PCNL and ESWL. Most patients who underwent URS and ESWL experienced Clavien-Dindo (CD) grade I-II complications. Percutaneous nephrolithotomy was associated with the highest complication rates, including 5 CD grade III and 3 CD grade IV complications and a mean postoperative hemoglobin drop of 0.47 to 1.83 g/dL. There were no CD grade V complications across all studies.

Conclusions: There was no difference in SFR between PCNL and URS. Ureteroscopy was associated with a smaller stone burden and fewer and less severe complications. Ureteroscopy was found to be more effective than ESWL with a higher SFR and comparable safety profile. Further large-scale randomized controlled trials are needed to confirm these findings.