Clinical bottom line
Medical expulsive therapy (MET) is a non-invasive treatment approach for facilitating the passage of ureteric stones, primarily using alpha-blockers like tamsulosin. While MET can be effective in increasing stone passage rates and reducing the need for surgical intervention, its efficacy varies depending on stone size and location. Current evidence supports the use of MET for stones less than 10 mm, particularly those located in the distal ureter, but highlights the need for individualized patient assessment.
What the evidence shows
A systematic review and meta-analysis by Campschroer et al. (2018) evaluated the efficacy of alpha-blockers in MET for ureteric stones and found that tamsulosin significantly increased the likelihood of stone passage compared to placebo, particularly for distal ureteric stones (PMID: 29566490). This finding aligns with the European Association of Urology (EAU) guidelines, which recommend MET as a treatment option for distal ureteric stones less than 10 mm in size (PMID: 30366595).
The SUSPEND trial (2015), a large multicenter randomized controlled trial, assessed the effectiveness of MET using tamsulosin and nifedipine. It concluded that while there was no significant difference in stone passage rates compared to placebo, subgroup analyses suggested potential benefits for larger stones and those located in the distal ureter (PMID: 26194933).
Caveats and uncertainty
Despite the supportive evidence for MET, several caveats must be considered. The SUSPEND trial's findings indicate that the overall benefit of MET may be limited, particularly for stones located in the proximal ureter or those smaller than 5 mm, where spontaneous passage is likely. Additionally, the variability in study designs, patient populations, and stone characteristics across trials contributes to uncertainty regarding the generalizability of results.
The potential side effects of alpha-blockers, such as hypotension and dizziness, should also be considered when prescribing MET, particularly in patients with pre-existing cardiovascular conditions. Furthermore, the lack of consensus on the optimal duration of MET and the criteria for treatment success necessitates careful patient monitoring and follow-up.
How this may change practice
The current evidence suggests that MET can be a valuable tool in the management of ureteric stones, particularly for patients with distal stones less than 10 mm. Clinicians should consider MET as part of a comprehensive treatment plan, taking into account individual patient factors such as stone size, location, and overall health status. Shared decision-making with patients is crucial, emphasizing the potential benefits and limitations of MET.
In practice, this may lead to more targeted use of MET for appropriate candidates, potentially reducing the need for surgical intervention and associated healthcare costs. As new research emerges, clinicians should remain informed about updates to guidelines and integrate these into their practice to optimize patient outcomes.