Does prior failed shock-wave lithotripsy impact outcomes of ureterorenoscopy? A systematic review and meta-analysis

OBJECTIVE: The study aimed to compare the outcomes of patients undergoing ureterorenoscopy (URS) after failed shock-wave lithotripsy (SWL) (Salvage URS) with those undergoing URS without any history of SWL (Primary URS). MATERIALS AND METHODS: PubMed. Embase, and CENTRAL databases were searched up to 10th January 2021 for studies comparing outcomes of salvage URS vs. primary URS. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for procedure success and complications. Operating time was summarized using mean difference (MD). RESULTS: Seven retrospective studies were included. Meta-analysis indicated no statistically significant difference in the success rates of URS between the salvage URS and primary URS groups (OR: 0.83 95% CI: 0.65, 1.06 I-2 =0% p=0.13). On subgroup analysis. the success rate was significantly reduced in the salvage URS group for renal stones (OR: 0.55 95% CI: 0.34. 0.91 I-2 =0% p=0.02) but with no difference for ureter stones OR: 0.90 95% CI: 0.67. 1.21 I-2 =0% p=0.49). Pooled analysis demonstrated a tendency of longer operating time in the salvage URS group as compared to the primary URS group, albeit with a statistically non-significant difference (MD: 8.91 95% CI: -0.56. 18.38 I-2 =98% p=0.07). Meta-analysis indicated significantly increased complications in the salvage URS group as compared to the primary URS group (OR: 1.83 95% CI: 1.34, 2.49 I-2 =0% p=0.0001). CONCLUSIONS: Evidence from retrospective studies suggests that patients undergoing salvage URS for renal stones have significantly lower success rates which is not the case for ureteral stones. There is a non-significant tendency of increased operating times for salvage URS. Complication rates are significantly higher for salvage URS as compared to primary URS. Future studies with propensity-score matching are required to strengthen current conclusions.