A simple technique of use of suction in RIRS

Abstract

Introduction: Retrograde intrarenal surgery (RIRS) has become standard first-line treatment for renal stones up to 2 cm. Sepsis is a serious complication of RIRS, often caused by high-pressure irrigation used to enhance intraoperative vision, which raises intrarenal pressure and causes intravasation. The “snow-globe” effect and haematuria due to raised IRP impair vision, often necessitating high-pressure irrigation that increases sepsis risk. Using low-pressure suction using the scope as conduit (direct in-scope suction, DISS) can reduce intrarenal pressure and improve vision during RIRS, potentially lowering the incidence of postoperative septic complications.

Objective: To compare the efficacy of suction via DISS technique with conventional RIRS (without suction) in preventing septic complications and to evaluate the stone-free rates (SFR) in both techniques.

Methods: From June 2023 to June 2024, 42 patients undergoing RIRS were randomized into two groups: 21 patients treated with RIRS using the DISS technique, and 21 with conventional RIRS without suction. The ‘no suction’ group underwent conventional RIRS using a Thulium Fiber Laser (60W), 9.5/11.5 Fr UAS, and 7.5 Fr flexible ureteroscope. The DISS RIRS was carried out with alternate use of irrigation and intermittent suction alongside standard RIRS protocols.

Results: Age, gender, and comorbidities were comparable between groups. Maximum stone size was slightly larger in the DISS group (13.24 ± 1.67 mm vs. 12.8 ± 1.50 mm, p = 0.37). Operative time was significantly shorter with DISS (45.38 ± 11.2 minutes) versus ‘no suction’ group (51.86 ± 7.94 minutes, p = 0.037). Median hospital stay was shorter for DISS group (1day) compared to ‘no suction’ group (2days). Postoperative fever (Clavien-Dindo I) and urosepsis (Clavien-Dindo IVb) were more common in the ‘no suction’ group. Residual fragment incidence did not differ significantly. However, SFR at 4 weeks was higher in the DISS group (86%) compared to no suction (71.5%).

Conclusion: This study demonstrates the feasibility and effectiveness of the DISS technique as a simple, cost-effective approach for reducing septic complications and reintervention rates by lowering intrarenal pressure and enhancing intraoperative vision compared to conventional RIRS without suction.