Novel Use of a Modified Triangular Prismatic Double-J Stent for 2- to 3-cm Renal Stones after One-Stage Retrograde Intrarenal Surgery

<b><i>Objectives:</i></b> To initially evaluate the outcomes of the modified triangular prismatic double-J (DJ) stent in the management of 2- to 3-cm renal stones after one-stage retrograde intrarenal surgery (RIRS). <b><i>Methods:</i></b> Patients with 2- to 3-cm renal stones who underwent one-stage RIRS with indwelling DJ stents were retrospectively evaluated. Eighty-eight patients who were placed the triangular prismatic DJ stents and 64 patients who received standard DJ stents were randomly included. The clinical characteristics and intraoperative and postoperative outcomes of the 2 groups were compared and analyzed. <b><i>Results:</i></b> The 2 groups had similar baseline characteristics. The urinary symptom score and pain score did not differ between groups (<i>p &#x3e;</i> 0.05). The residual fragments of the 2 groups were similar 1 day after operation (<i>p =</i> 0.134). There was no significant difference in residual fragments in the lower calyx between groups at the time of stent removal (<i>p =</i> 0.834). The patients in the modified group had better spontaneous passage of residual fragments in the nonlower calyx than those in the standard group during the 2 weeks with the stents (<i>p</i> = 0.005). Fewer patients in the modified group had residual fragments (&#x3e;4 mm) in the nonlower calyx (<i>p</i> = 0.026) and ureter (<i>p</i> = 0.010) than the patients with standard stents at the time of stent removal. <b><i>Conclusion:</i></b> The indwelling triangular prismatic DJ stent is a safe and efficient treatment method. Patients with these stents had better spontaneous residual fragment passage than those with the standard DJ stents.