ObjectiveTo investigate the protective effect of two double-J stents placement combined with N-trap stone basket against postoperative ureteral stricture after ureteroscopic Ho: YAG lithotripsy.

MethodsInformation of patients with impacted ureteral stones who underwent single F7 or two F6 double-J stents placement during ureteroscopic Ho: YAG lithotripsy was retrospectively reviewed.A total of 97 pairs of patients (n=194) were distributed into two groups (single-F7 stents group and two-F6 stents group) by means of propensity score matching with stone size and impaction period being predictors.Postoperative ureteral stricture rate (with stents in place for 8 to 10 weeks and 1 year follow-up), stone-free rate and stent-related urinary symptom incidence were compared between two groups.

ResultsOn the first day after operation, the overall stone free rate of patients reached 88.1% (171/194), and there was no significant difference between the two groups (P>0.05).During follow-up after stent removal, 22 cases of ureteral stricture (overall incidence 11.3%) were diagnosed.The incidence of ureteral stenosis in the single-F7 stents group was significantly higher than that in the two-F6 stents group (P < 0.01).Indwelling two F6 double-J stents was a protective factor for ureteral stricture after ureteroscopic lithotripsy (RR=0.294, 95%CI: 0.113-0.766).Incidence of stent-related urinary symptoms (at least one of gross hematuria, urgency, frequent urination, lower abdominal pain, flank pain) reached almost 100% in both groups, and showed no significant difference(P>0.05).

ConclusionsAfter ureteroscopic Ho: YAG lithotripsy for incarcerated ureteral calculi, the placement of two double-J stents combined with N-trap stone basket can safely and reliably reduce the risk of postoperative ureteral stricture.