Acute obstruction after ureteral stenting and nephrostomy

Causes of acute obstruction

• Stent migration.
• Stent occlusion (encrustation, mucus, clots).
• Stent/nephrostomy malposition.
• Tissue edema after instrumentation.
• Compression of the stent by a tumor or stone.

Clinical presentation

• Flank pain.
• Rising creatinine, oliguria.
• Fever if infection develops.
• Increasing hydronephrosis on ultrasonography.

Diagnosis

• Ultrasonography to assess hydronephrosis and stent position.
• CT to identify the level of obstruction.
• Contrast radiography to assess stent/nephrostomy position.

Emergency management

• Migration/occlusion: replace the stent or nephrostomy.
• Edema: conservative treatment (antibiotics, anti-inflammatory medication, alpha-blockers).
• Compression by a tumor/stone: urgent drainage (nephrostomy) + definitive treatment after stabilization.
• Sepsis with obstruction: urgent drainage.

Algorithm