Lee SW et al, 2015: Comparative efficacy and safety of various treatment procedures for lower pole renal calculi: a systematic review and network meta-analysis.
Lee SW, Chaiyakunapruk N, Chong HY, Liong ML
School of Pharmacy, Monash University Malaysia, Bandar Sunway, Malaysia
OBJECTIVE: To compare the effectiveness of various treatments used for lower pole renal calculi.
METHODS: We searched PubMed, EMBASE, CINAHL, the Cochrane Collaboration's Database of Systematic Reviews, the Cochrane Collaboration Central Register of Controlled Clinical Trials as well as ClinicalTrials.gov for reports up to April 1, 2014. Search was supplemented with abstract reports from various urology conferences. All randomised, blinded clinical studies including patients treated for lower pole renal calculi <20mm were included for review. Two authors independently reviewed 5,194 articles identified and selected 13 trials for analysis. Network meta-analysis was performed to generate comparative statistics while quality was assessed with Jadad composite scale and risk of bias.
RESULTS: All treatment modalities examined: percutaneous nephrolithtripsy (PNL), ureterenoscopy (URS) and shockwave lithotripsy with adjuvant therapy such as
inversion, hydration and forced diuresis (SWL & Adj) were more effective than shockwave lithotripsy (SWL) therapy alone, with risk ratio (95% confidence intervals) of being stone free: PNL 2.19 (1.62-2.96); URS 1.23 (1.03-1.48); and SWL & Adj 1.30 (1.03-1.63). However, patients treated with other treatment modalities also have a higher risk of adverse events compared with SWL therapy, but there was no evidence of a convincing difference between the various techniques and adverse events.
CONCLUSION: In stones <10mm, SWL & Adj appears to have better stone clearance , lower risk of adverse events and need for further treatment. PNL was most effective treatment in larger sized stones, after considering both efficacy and safety of treatment. These should be considered by both physicians and patients
alike when considering on the choice of treatment and in the revision of clinical practice guidelines.
BJU Int. 2014 Nov 10. doi: 10.1111/bju.12983. [Epub ahead of print]
Meta-analyses frequently show three results: they prove what is already known about the topi, they show that there are only a limited number of publications on the topic and that the publications are of low quality. Even a careful selection does not preclude the GIGO (garbage in garbage out) effect.
The reader can nevertheless profit by using them as a guide to the usually small number of original publications to get a better insight into the subject: Meta-analyses on lower pole stones usually include the publication by Pearl et al. Prospective, randomized trial comparing shock wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1 cm or less. J Urol. 2005 Jun;173(6):2005-9.
In this study it took 19 departments and 45 months to enrol 67 patients with lower pole stones treated on protocol (32 SWL and 35 URS). In this long time period 5, 7 and 1 clinics recruited only 1, 2 or 3 patients respectively. There must have been a serious bias of patient selection which can only be realized when looking at the original literature.
Sometimes the original literature offers more information than the meta-analysis. In this review series a publication by JF Donaldson et al. Systematic Review and Meta-analysis of the Clinical Effectiveness of Shock Wave Lithotripsy, Retrograde Intrarenal Surgery, and Percutaneous Nephrolithotomy for Lower-pole Renal Stones. Eur Urol. 2014 Oct 23 quotes another landmark publication by Albala et al. Lower pole I: a prospective randomized trial of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy for lower pole nephrolithiasis-initial results J Urol. 2001 Dec;166(6):2072-80 as not reporting complications. But in fact they did and the complications of PNL were more serious than those of SWL.
The present meta-analysis is a nice exception from the usual MAM (meta-analysis murmur). They have included publications on SWL plus adjuvant therapy such as inversion, hydration and forced diuresis and could show that the results were better than SWL alone and equivalent to URS at a presumably lower cost.