Medical Expulsive Therapy in Urolithiasis: A Review of the Quality of the Current Evidence

Abstract

Context: Medical expulsive therapy (MET) is widely used to promote spontaneous passage of urinary stones. However, there is conflicting evidence on the actual role of MET.

Objective: To evaluate the conformance of published randomized controlled trials (RCTs) on MET with the Consolidated Standards for Reporting Trials (CONSORT) criteria, and to clarify the current role of MET in management of urinary stones on the basis of our findings.

Evidence acquisition: We carried out an electronic search of the Cochrane Library, PubMed, and Embase databases for RCTs on MET. For each RCT included, we created a checklist table documenting the minimum essential items that should be included in reports of RCTs according to the CONSORT 2010 statement.

Evidence synthesis: Clinical heterogeneity between pooled studies in terms of the MET given, inclusion criteria, sample size, pre- and post-treatment imaging, and differential follow-up was profound. The overall methodological rigor of the pooled studies was low, as indicated by the moderate to poor conformance of the studies with the CONSORT criteria. The aforementioned reasons may explain the discrepancies found between the supporting results of several meta-analyses and those of well-designed placebo-controlled double-blind studies revealing no benefit from MET. Recent well-designed RCTs have shown no benefit from α-blockers versus placebo. However, on the basis of sensitivity analyses in a recently published meta-analysis, α-blockers may still promote spontaneous expulsion of large stones.

Conclusions: Conflicting data on MET may be explained by clinical heterogeneity and methodological flaws. Urologists must decide whether to follow single, large, well-conducted RCTs or pooled data from meta-analyses. The latter still support selective use of MET for larger urinary stones.

Patient summary: In this review we tested the accuracy of the studies published on various medications given to promote spontaneous passage of stones from the ureter. Although the majority of the studies were not designed properly, there is still some evidence to support medical expulsive therapy.

Keywords: Kidney stone; Medical expulsive therapy; Ureteric stone; Urolithiasis.