MP44-02: Favorable Outcomes of Contemporary Percutaneous Nephrolithotomy versus Retrograde Intrarenal Surgery for Treatment of Renal Stones in Adult Patients: A Cochrane Review

Leah Soderberg, Rochester, MN, Maylynn Ding, Hamilton, Canada, Vernon Pais, Lebanon, NH, Michael S Borofsky, Minneapolis , MN, Robin Parker, Halifax , Canada, Philipp Dahm*, Minneapolis, MN

Introduction: Improved instrumentation and modern technology have advanced the use of both percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). We performed this systematic review (SR) and meta-analysis to assess their comparative effectiveness in treating renal stones.

Methods: We conducted this SR according to an a priori, registered protocol published in the Cochrane Library. We performed a comprehensive literature of multiple databases without restriction based on language or publication status (latest search: April 30, 2021). We assessed 3 primary outcomes (reported below) as well as 14 additional secondary outcomes. The certainty of evidence (CoE) was assessed using GRADE.

Results: Of 1915 screened references, we included 35 unique randomized controlled trials (RCTs) of which 23 studies were reported in full-text and 12 in abstract form only. Access size ranged from 4.85 Fr to 30 Fr across studies and stone size ranged from 10.1 to 39.1. mm. Based on a predefined subgroup analysis based on access size, =24 Fr may increase stone-free rates (RR 1.35; 95% CI 1.12 to 1.64; studies=8) compared to RIRS, whereas 15–23 Fr (RR 1.04; 95% CI 0.99 to 1.09; studies=9) and <15 Fr (RR 1.07; 95% CI 1.03 to 1.12; studies=8), may be similarly effective (test for interaction: p=0.02) as RIRS. There may be little to no effect on major complications (RR 1.06, 95% CI 0.66 to 1.69; participants=2912; studies=29; I2=15%; low CoE). The need for secondary interventions may be reduced with PCNL (RR 0.32, 95% CI 0.17 to 0.57; participants=1968; studies=21; I2=63%; low CoE). PCNL probably results in little to no difference in narcotic use measured in morphine equivalents (MD 5.23 higher, 95%CI 2.87 higher to 7.59 higher; participants=91; studies=2; I2=0%; moderate certainty of evidence). Predefined secondary analyses for stone free rates also suggested potential subgroup effects based on stone burden; RR 1.05 (95 CI 1.00 to 1.10) for solitary and RR 1.26 (95 CI 1.09 to 1.47) for multiple stones (test for interaction: p=0.02) and stone location; RR 1.06 (95% CI 1.01 to 1.12) for lower pole stones and RR 4.33 (95% CI: 2.09 to 8.99) for non-lower pole stones (test for interaction: p=0.0002) but not stone size (=20 mm versus >20 mm).

Conclusions: Findings of this review that include a large number of recent studies using an access size <24 Fr, suggest more favorable outcomes for PCNL versus RIRS when the access size is =24, there are multiple stones and stone(s) are in a non-lower pole location. Our confidence in these findings is reduced due to study limitations, inconsistency, and concerns over publication bias as well the large proportion of across-, rather within study subgroup comparisons.

Source of Funding: None