What is the next step after removal of a midureteral stone when intussuscepted mucosa is seen and there is no guidewire access and the ureteral orifice cannot be cannulated?

Management of Intussuscepted Ureteral Mucosa After Stone Removal

When intussuscepted mucosa is encountered after midureteral stone removal with no guidewire access and inability to cannulate the orifice, percutaneous nephrostomy (PCN) placement is the recommended next step to ensure urinary drainage and prevent obstruction-related complications.

Initial Management Algorithm

• Percutaneous nephrostomy (PCN) should be performed as the primary intervention when retrograde access is impossible due to intussuscepted mucosa 1
• PCN provides immediate decompression of the collecting system, preventing potential complications such as infection, renal damage, and urinary extravasation 1
• When performed with image guidance, PCN has a technical success rate approaching 100%, making it a reliable option in this challenging clinical scenario 1

Technical Considerations for PCN Placement

• Ultrasound guidance is typically used for initial access, followed by fluoroscopy for nephrostomy tube placement 1
• A nephrostomy tube of appropriate size should be selected based on the clinical situation - larger tubes may be warranted if there is concern for debris or blood clots 1
• Complication rates for PCN are generally low (approximately 10%) with major complications being uncommon 1

Subsequent Management Options

• After successful PCN placement, several options exist for definitive management:
  • Delayed antegrade ureteral stent placement via the nephrostomy tract once the intussusception resolves 1
  • Combined "rendez-vous" technique where antegrade and retrograde approaches are used simultaneously to establish ureteral patency 1
  • Surgical repair if the intussusception does not resolve or if there is concern for ureteral viability 1

Special Considerations

• If the intussuscepted segment appears non-viable, surgical options should be considered:
  • For proximal ureteral injuries, primary repair over a ureteral stent is preferred when possible 1
  • For distal ureteral injuries, reimplantation or primary repair over a stent may be appropriate 1
• Temporary urinary diversion with PCN allows time for inflammation to subside and may facilitate subsequent interventions 1

Potential Pitfalls and Complications

• Delaying decompression in an obstructed system can lead to infection, sepsis, and permanent renal damage 2
• Attempting forceful cannulation of the intussuscepted segment may worsen the condition and potentially cause perforation 3
• PCN-related complications can include bleeding, infection, tube dislodgement, and sepsis - careful technique and appropriate antibiotic coverage are essential 1
• Intussusception is a rare complication of ureteroscopy that may require more extensive intervention if not properly managed 3

Long-term Management

• Once the acute situation is stabilized with PCN, definitive management should be planned based on:
  • The extent and viability of the intussuscepted segment 1
  • The patient's overall clinical condition 1
  • The availability of appropriate expertise and equipment 1
• In rare cases where the intussusception does not resolve, surgical intervention with ureteral reconstruction may be necessary 3