Crossfire: To test or not to test

Urologists debate the value of stone analysis and metabolic urine testing for their patients.

Kymora Scotland, MD, PhD, and Justin Friedlander, MD
Kymora Scotland, MD, PhD, and Justin Friedlander, MD

Do urologists really need stone analysis and metabolic urine testing? That was the question posed at Saturday afternoon’s Crossfire: Controversies in Urology Debate: “Do We Really Need Stone Analysis and Metabolic Urine Testing?”

Moderated by Glenn M. Preminger, MD, professor of urologic surgery at Duke University Hospital in Durham, North Carolina, the Crossfire session teamed “Yea” panelists Justin Friedlander, MD, and Sara Best, MD, against the “Nay” team of Kymora Scotland, MD, PhD, and Ryan Hsi, MD.

Dr. Friedlander, director of endoscopic urologic surgery and the Comprehensive Kidney Stone Center at Albert Einstein Medical Center in Philadelphia, Pennsylvania, came out swinging, saying that yes, stone analysis and metabolic testing are needed for several reasons.

“It helps make the diagnosis; it helps reduce recurrence; it is cost-effective for our recurrent stone formers; and it helps with compliance and management,” Dr. Friedlander said. “It is also supported by the AUA guidelines and it gives hope to lifelong disease.”

The AUA’s current medical management guidelines include the following statements:

  • When a stone is available, clinicians should obtain a stone analysis at least once. (Clinical Principle)
  • Metabolic testing should consist of one or two 24-hour urine collections obtained on a random diet and analyzed at minimum for total volume, pH, calcium, oxalate, uric acid, citrate, sodium, potassium and creatinine. (Expert Opinion)

Dr. Scotland, assistant professor and endourologist at UCLA in Los Angeles, California, conceded that stone analysis and metabolic testing are guideline-supported items; provide patients with quantifiable targets; help with screening for rarer diseases like cystinuria and primary hypoxia; help noninvasively track patient compliance with fluids and medications; and give hope to patients who have a lifelong disease.

“But let's not forget the actual endpoint here,” Dr. Scotland said. “[It] should be stone recurrence. There is no reason to do all of this if there is no effect on stone recurrence.

“It is my position that stone analysis and metabolic testing provide limited utility for most stone formers. [The tests] do not predict recurrence. They do not prevent recurrence, and they may, in fact, increase cost.”

In her rebuttal statement, Dr. Best, an associate professor of urology at the University of Wisconsin School of Medicine and Public Health in Madison, said the tests allow for cost-effective precision medicine, improve patient buy-in and maximize patient outcomes.

Dr. Hsi, an associate professor of urology at Vanderbilt University Medical Center in Nashville, Tennessee, countered by positing that the tests are challenging to interpret, uncommonly performed and impractical in certain clinical scenarios.

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