Assessing Stone Clearance in Non-Stented Patients Undergoing Retrograde Intrarenal Surgery with a 9.5 Fr Re-access Ureteric Sheath: A Single-Center Study
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Abstract
Objective: To assess stone clearance and perioperative outcomes in non-prestented patients undergoing RIRS using a 9.5 Fr re-access ureteral sheath and to identify clinical and procedural characteristics associated with complete versus partial stone clearance.
Methodology: This retrospective observational analytic cohort study was conducted at the Pakistan Kidney and Liver Institute and Research Centre, Lahore from September 2018 to August 2023. A total of 179 non-prestented patients who underwent RIRS using a 9.5 Fr re-access ureteric sheath were included. Stone clearance was assessed using postoperative non-contrast computed tomography (CT) and categorized as complete or partial according to the predefined residual-fragment criteria. Baseline, clinical, operative, and postoperative characteristics were compared between patients with complete and partial stone clearance to identify factors associated with clearance status. Continuous variables were analyzed using the independent-samples t-test or Mann–Whitney U test, as appropriate, while categorical variables were compared using the chi-square or Fisher’s exact test.
Results: Complete stone clearance was achieved in 150 patients (83.8%), whereas 29 patients (16.2%) had partial clearance. Patients with partial clearance had significantly larger stones than those with complete clearance (median 1.65 vs. 1.10 cm, p<0.001) and higher preoperative white blood cell counts (p=0.011). Residual fragments on postoperative imaging and the need for additional procedures were significantly more frequent among patients with partial clearance (p<0.001 for both). Partial clearance was also associated with longer hospital stay (p=0.043), larger residual fragment size (p<0.001), and delayed DJ stent (p<0.001) and Foley catheter removal (p=0.006). Operative and laser times did not differ significantly between the groups (both p>0.05).
Conclusion: RIRS using a 9.5 Fr re-access ureteric sheath achieved a high rate of complete stone clearance in this non-prestented cohort. Within this study population, larger stone size was associated with a greater likelihood of partial clearance. These findings suggest that a 9.5 Fr re-access sheath may permit RIRS without routine preoperative stenting in appropriately selected patients; however, comparative studies including prestented patients are required to determine the independent effect of preoperative stenting on stone clearance and procedural outcomes.
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