BERKELEY, CA (UroToday.com) - The incidence of urolithiasis in the developed world is increasing in parallel to dietary changes, diabetes, and obesity. The lower pole is the most common location for any renal stone. Lower pole stones (LPS) are also the most likely to require active treatment as spontaneous passage from this dependent location is less common. Stone fragments are also less likely to pass following shock wave lithotripsy (SWL). These factors make the treatment of LPS controversial.
Our systematic review aimed to robustly assess the available evidence on the relative benefits and harms of SWL, retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) in adults. We identified 2 741 records, from which 7 RCTs were eligible for inclusion, recruiting a total of 691 patients. This review provides the first level 1a evidence for the treatment of LPS.
For the primary outcome of stone-free rate (SFR) at up to 3 months, both PNL (RR 2.04 [95% CI 1.50-2.77]) and RIRS (RR 1.31 [1.06-1.62]) had higher SFR than SWL, for which there was moderate quality of evidence (assessed using GRADE methodology). The advantage of both PNL and RIRS over SWL was greatly diminished for ≤ 10mm stones, although it remained statistically significant. PNL and RIRS were only compared in one RCT, reporting only preliminary results. Median SFR from all included RCTs favoured PNL (96.3%) over RIRS (91.7%) and SWL (54.5%).
For the secondary outcomes of unplanned procedure rate, re-treatment rate, and complication rates, there was only low or very low quality of evidence. Inconsistent or poorly defined thresholds and direction of effects rendered meaningful interpretation of these outcomes impossible. There were inconsistent findings regarding other patient-important outcomes such as acceptability, analgesic requirements, and time to return to activities for the comparison of SWL vs. RIRS, possibly due to heterogeneity of stone size and number of SWL treatments required. However, SWL was associated with a shorter hospital stay than RIRS and PNL. Economic outcomes were not reported in any RCTs.
Further research is therefore urgently required to compare PNL and RIRS and secondary and economic outcomes for all treatment comparisons.
Written by:
James F. Donaldson,a Thomas B.L. Lam,a, b and Samuel McClintona, b as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
aDepartment of Urology, Aberdeen Royal Infirmary, Aberdeen, UK
bAcademic Urology Unit, University of Aberdeen, Aberdeen, UK