From the Guidelines
The patient with acute kidney injury, a 4mm stone at the vesicoureteric junction, and hydronephrosis requires urgent urological intervention, ideally within 24-48 hours, with a ureteral stent placement to relieve the obstruction and prevent further kidney damage. The presence of acute kidney injury and hydronephrosis indicates significant obstruction that needs immediate attention, as emphasized by the consensus among international and European associations on priority procedures during the COVID-19 pandemic 1. Although the absence of infection is somewhat reassuring, the combination of AKI and hydronephrosis is a compelling indication for urgent decompression, either by ureteral stent insertion or placement of a nephrostomy tube, deferring stone removal 1.
Key Considerations
- The patient should receive appropriate pain management with medications such as ketorolac 30mg IV or morphine 4-6mg IV as needed, prior to stent placement.
- Intravenous hydration should be carefully managed, balancing the need to maintain urine flow while avoiding volume overload in the setting of compromised kidney function.
- The choice between ureteral stent placement and percutaneous nephrostomy (PCN) should be based on individual patient factors, with ureteral stent placement being a safe and effective option in the presence of obstructing ureteral stones and sepsis 2.
- A randomized comparative study demonstrated no significant difference between PCN and double-J-stent groups in regard to operative and imaging times, period for return to a normal creatinine level, and failure of insertion, but a higher number of subsequent interventions were needed in the PCN group 2.
Management Plan
- Ureteral stent placement should be performed promptly to relieve the obstruction and prevent further kidney damage.
- Close monitoring of renal function with daily creatinine measurements is necessary until improvement is documented.
- Definitive stone management can be planned once kidney function stabilizes, either through ureteroscopy or shock wave lithotripsy.
- The patient's clinical condition should be closely monitored for any signs of worsening or development of infection, which may require adjustment of the management plan.
From the Research
Urgency for Stent Placement
The urgency for stent placement in a patient with acute kidney injury, a 4mm stone in the vesicoureteric junction (VUJ), and hydronephrosis, without evidence of infection, can be evaluated based on the following factors:
- The presence of acute kidney injury and hydronephrosis indicates a need for urgent relief of the obstruction to prevent further renal damage 3, 4.
- The size of the stone (4mm) is relatively small, but its location in the VUJ can still cause significant obstruction and require intervention 5.
- The absence of infection reduces the urgency for immediate intervention, but the patient's condition still requires prompt attention to prevent complications 6.
Considerations for Stent Placement
When considering stent placement, the following factors should be taken into account:
- The patient's overall health status and ability to tolerate the procedure 4.
- The potential risks and complications associated with stent placement, such as ureteral damage or stent occlusion 5, 7.
- The need for ongoing management and follow-up to ensure the stent remains patent and functional 7.
Comparison of Stent Placement and Percutaneous Nephrostomy
Studies have compared the outcomes of stent placement and percutaneous nephrostomy in patients with obstructive uropathy:
- A systematic review and meta-analysis found no significant difference in clinical outcomes between the two procedures for patients with severe urinary tract infections and obstructive urolithiasis 6.
- Another study found that percutaneous nephrostomy was superior to ureteral stents for diversion of hydronephrosis caused by stones, especially in patients with high temperature and males 3.
- A prospective, randomized study in children with obstructive calcular anuria and acute renal failure due to bilateral ureteric calculi found that JJ stents were associated with fewer complications and a shorter operative time compared to percutaneous nephrostomy tubes 5.