What are the implications of bilateral renal non-obstructive calculi, with a larger burden on the right kidney measuring up to 7 millimeters?

From the Guidelines

For bilateral renal non-obstructive calculi with a larger 7 mm stone on the right side, the recommended treatment is either Shock Wave Lithotripsy (SWL) or Ureteroscopy (URS), as both have acceptable stone-free rates with less morbidity than Percutaneous Nephrolithotomy (PCNL) for cumulative stone burdens <20 mm. The patient's total non-lower pole renal stone burden is ≤ 20 mm, which aligns with the guidelines that suggest SWL or URS as viable options 1. Considering the size of the stones, the treatment options should prioritize minimizing morbidity while achieving a stone-free state. Key points to consider in the management include:

• The stone size and location, with the larger stone being 7 mm on the right side
• The cumulative stone burden being less than 20 mm, which makes SWL or URS suitable options 1
• The importance of symptom management and prevention of future stone formation through lifestyle and dietary modifications
• Consultation with a urologist to determine the best course of treatment for the specific case, considering factors such as stone composition, patient preferences, and the potential need for repeat procedures. Given the guidelines, SWL or URS are the preferred treatments for symptomatic patients with a total non-lower pole renal stone burden ≤ 20 mm 1.

From the Research

Treatment Options for Bilateral Renal Non-Obstructive Calculi

• The treatment of bilateral renal non-obstructive calculi can be challenging, and various options are available, including percutaneous nephrolithotomy (PCNL) and shock wave lithotripsy (SWL) 2.
• A study comparing synchronous and asynchronous bilateral PCNL found that synchronous PCNL was a well-tolerated, safe, cost-effective, and expeditious treatment option, with similar stone-free rates and blood loss per operation compared to asynchronous PCNL 2.
• However, the study also noted that synchronous bilateral PCNL should be considered in patients in whom the first stage of stone removal is accomplished quickly and safely, and that excessive bleeding may be encountered more frequently on the first side, thereby delaying management of the second side to a later date 2.

Role of Alpha-Blockers in Medical Expulsive Therapy

• Alpha-blockers have been shown to be effective in promoting the passage of stone fragments after SWL, with a meta-analysis finding that alpha-blockers may improve clearance of stone fragments after SWL, reduce the need for auxiliary treatments, and reduce major adverse events 3.
• Another study found that alpha-blockers increased the stone-free rate and reduced the time to stone expulsion in patients with ureteral stones, and that alpha-blockers should be offered as part of medical expulsive therapy as one of the primary treatment modalities 4.
• A meta-analysis of placebo-controlled trials found that alpha-blockers were effective in treating distal urinary tract stones, but had no significant effect on the clearance of stones in the urinary tract overall, and were likely to cause dizziness and retrograde ejaculation 5.

Considerations for Treatment

• The size and location of the stones, as well as the patient's overall health and medical history, should be taken into account when determining the best course of treatment 2, 3, 4, 6, 5.
• The use of alpha-blockers as medical expulsive therapy may be beneficial in promoting the passage of stone fragments and reducing the need for auxiliary treatments, but may also cause adverse effects such as dizziness and retrograde ejaculation 3, 4, 5.