New study supports MET for larger ureteric stones

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A recent review of medical literature adds to the debate surrounding medical expulsive therapy for stone disease.

Medical expulsive therapy with alpha-blockers can promote clearance of ureteric stones 5 mm and larger, suggests the findings of a multicenter review of medical literature.

“Alpha-blockers appear to be efficacious in the management of patients with ureteral stones who are eligible for a trial of conservative management, and the benefit appears to be greater to those patients who have larger stones,” first author John M. Hollingsworth, MD, of the University of Michigan Medical School, Ann Arbor told Urology Times.

A 2015 multicenter study in The Lancet (2015; 386:341-9) had questioned the benefit of off-label alpha-blocker use and drew debate around the urologic community. Looking at 1,136 subjects in the United Kingdom, the study found no difference between medical expulsive therapy and placebo. However, a high rate of spontaneous stone passage among controls might better explain those results, Dr. Hollingsworth said.

“Our study was in part a response to the large Lancet trial to sort through some of the information that they had and put it into context of other kidney stone research and published studies that have come out since. The U.K. study wasn’t designed to look at stone size or location, and what we thought is if we are able to pull data from all published studies, we may be able to examine that in more detail,” Dr. Hollingsworth said.

The authors pooled a total of 55 randomized controlled trials comparing alpha-blockers to placebo or control and considered stone size and location in the 5,990 study subjects to see whether either one was a factor in successfully passing the stone.

Next: 49% greater likelihood of ureteric stone passage with off-label alpha-blocker compared with no treatment or placebo

The review, published online in The BMJ (2016; Dec. 1:i6112), revealed a 49% greater likelihood of ureteric stone passage with an off-label alpha-blocker compared with no treatment or placebo. Treated patients with stones 5 mm or larger had a 57% greater likelihood of stone clearance. The study showed no treatment benefit for those with smaller ureteric stones.

Also see: Persistent decline in renal function seen after first stone case

“Stone passage occurred at 8.8 and 13.3 days on average in the treatment and control groups, respectively,” said Dr. Hollingsworth, adding stone passage happened 3.79 days sooner among patients who received alpha-blockers compared with those who received no treatment or placebo. “We were surprised to find that the benefit appeared to be independent of stone location. Our pool analysis suggested that even patients with upper and middle ureteric stones appeared to benefit from treatment.”

That data can be used to help identify patients who are more likely to benefit from alpha-blockers and shows stone size is a factor when recommending alpha-blockers to kidney stone patients.

Dr. Hollingsworth believes getting more information from patients on what they value and prefer on stone management would be beneficial for future studies.

“Also, one of the things we observed in the U.K. study is that there was this high baseline rate of stone passage in the control group and we saw certain countries where the baseline rate was much higher (in Australia and the U.K.) than it was in other parts of Europe or the U.S. Understanding that phenomenon would be interesting and maybe more direction for future research,” Dr. Hollingsworth added.

In addition to Dr. Hollingsworth, study authors include Benjamin K. Canales, MD, of the University of Florida College of Medicine, Gainesville; Philipp Dahm, MD, University of Minnesota, Minneapolis; Mary A. M. Rogers, PhD, MS, and Phyllis Yan, both of the University of Michigan; Shyam Sukumar, MD, University of Minnesota; and Gretchen M. Kuntz, MSW, MLIS, of the University of Florida.

Look for a feature on medical expulsive therapy for stone disease in the January 2017 issue of Urology Times.