BACKGROUND AND PURPOSE:

• Small (≤6 mm), asymptomatic kidney stones may be removed surgically or managed conservatively 
• Sorensen et al. (NEJM, 2022) sought to determine whether small kidney stone removal vs observation result in in fewer relapses

METHODS:

• Multicenter, randomized, controlled trial
• Participants
  • Scheduled for endoscopic surgical treatment of a primary stone
• Interventions
  • Removal of small, asymptomatic secondary stones
  • No removal (control)
• Primary outcome
  • Relapse: Future emergency department visits, surgeries, or growth of secondary stones

RESULTS:

• Removal group: 38 patients | Control group: 35 patients
  • Mean follow-up: 4.2 years
• The treatment group had a longer time to relapse than the control group
  • P<0.001
• The restricted mean time to relapse was 75% longer in the treatment group than in the control group
  • Removal group: 1631.6 days
  • Control group: 934.2 days
• The risk of relapse was 82% lower in the treatment group than the control group
  • Removal group: 16% relapsed
  • Control group: 63% relapsed
  • Hazard ratio (HR) 0.18 (95% CI, 0.07 to 0.44)
• Additional surgery time in the removal group
  • 25.6 (IQR, 18.5 to 35.2) minutes
• Adverse events
  • Emergency department visits within 2 weeks of surgery
    • Removal group: 5 patients
    • Control group: 4 patients
  • Patient reported passing kidney stones
    • Removal group: 8 patients
    • Control group: 10 patients

CONCLUSION:

• For patients undergoing endoscopic removal of primary kidney stones, removing small, secondary, asymptomatic stones at the time of surgery reduced the risk of relapse, and lengthened the time to relapse
• Additional surgery time for the treatment group was minimal
• The authors state

Results of our prospective, randomized trial support removal of small, asymptomatic renal stones at the time of surgery to remove a symptomatic stone

The additional 25 minutes needed to remove small, asymptomatic renal stones at the time of surgery for a primary stone (extending the procedure by 38%) should be weighed against the potential need for repeat surgery in the 63% of patients who had a relapse

Learn More – Primary Sources:

Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse

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