Immediate Shockwave Lithotripsy vs Delayed Shockwave Lithotripsy After Urgent Ureteral Stenting in Patients with Ureteral or Pyeloureteral Urolithiasis: A Matched-Pair Analysis.

Introduction: The most common cause of acute renal colic is a ureteral obstruction caused by ureterolithiasis. Urgent intervention is often necessary due to intractable pain. Early extracorporeal shockwave lithotripsy (SWL) as an alternative treatment option to ureteral stenting becomes forgotten in times of rising ureterorenoscopy. However, definitive guidelines are lacking, in which urgent treatment should be preferred in the absence of signs of infection. Therefore, we assessed efficacy and safety of early SWL (eSWL) to secondary SWL (sSWL) after urgent ureteral stenting. Patients and Methods: One hundred four patients treated between January 2015 and November 2017 for obstructive ureterolithiasis were matched regarding stone size, stone localization, and assigned to group eSWL ( n  = 52) or group sSWL ( n  = 52). The eSWL group received shock waves (without prior ureteral stenting) and sSWL group ureteral stenting within 48 hours from diagnosis. Thereafter, patients in group sSWL were treated with shock waves for a median of 23 ± 14.6 days after ureteral stenting. Stone-free rates, complication rates, and reintervention rates were assessed. Univariable and multivariable logistic regression was applied to find predictors of outcomes in the two treatment groups. Results: Overall, there was no statistically significant difference between both groups regarding stone-free rate and complication rate. Reinterventions were more often addressed for patients in group sSWL ( p  = 0.05). eSWL was significantly superior to sSWL regarding stone-free rates for stones between 6 and 9 mm ( p  = 0.04). At the multivariable multinomial logistic regression none of the two treatment modalities was associated with better outcomes. A body mass index ≥30 was associated with a reduced 6-week stone-free status ( p  = 0.04), whereas stones ≥8 mm were associated with an increased need of reintervention ( p  = 0.04). Conclusion: eSWL seems to be an effective and safe emergency procedure compared with sSWL after urgent stenting within 6 weeks and should be considered as a treatment option in patients without absolute indications for immediate ureteral drainage. Clinical trial registration number: 2019-00155.