What is the procedure for placing an antegrade stent?

Antegrade Ureteral Stent Placement Procedure

Antegrade ureteral stent placement is a safe and effective procedure for urinary tract decompression when retrograde stenting fails or is not feasible, with technical success rates approaching 95%. 1

Indications

• Failed retrograde ureteral stenting attempts
• Urinary diversion after cystectomy
• Malignant ureteral obstruction, especially with:
  • Extrinsic compression
  • Ureteric orifice occlusion due to tumor
  • Tight strictures near the uretero-vesical junction
  • Obstruction length >3 cm
• Upper ureteral stones (large, impacted)
• Combined renal stone removal
• Pyonephrosis requiring decompression

Procedural Steps

1. Initial Access

   • Typically performed after placement of a percutaneous nephrostomy (PCN) catheter
   • PCN is usually placed under ultrasound and fluoroscopic guidance
   • Access site is generally through a posterior calyx

2. Pre-Procedure Preparation

   • General anesthesia or conscious sedation
   • Antibiotic prophylaxis
   • Blood pressure control (may require lowering during critical steps)

3. Stent Insertion Technique

   • Equipment needed:

     • Long vascular introducer sheath
     • Guidewire
     • Double-J stent
     • Pusher catheter with radiopaque markers

   • Steps:

     1. Insert guidewire through existing PCN tract into collecting system
     2. Advance guidewire down the ureter past the obstruction into the bladder
     3. Place vascular introducer sheath over guidewire
     4. Insert Double-J stent through the sheath
     5. Position proximal pigtail in renal pelvis using the sheath to hold portion of pigtail in extended state
     6. Deploy distal pigtail in bladder
     7. Remove guidewire and sheath
     8. Confirm proper positioning with fluoroscopy

4. Post-Procedure Management

   • Safety nephrostomy catheter may be left temporarily
   • Check nephrostogram typically performed 2-3 days after procedure to confirm stent patency
   • If stent is functioning properly, safety nephrostomy can be removed

Success Rates and Complications

• Technical success rate: >90-95% 1, 2
• Complications:
  • Major complication rate: 2-4% 3
  • Infection/sepsis: 4-6% 1
  • Stent migration: 5% 1
  • False tract formation: rare
  • Malposition: rare
  • Bleeding: 5% 1

Advantages Over Retrograde Stenting

1. Higher success rate in malignant obstructions 3
2. Avoids need for cystoscopy
3. Significantly faster procedure time (5.2 minutes vs. 39.35 minutes in laparoscopic settings) 4
4. Better anatomical delineation when used in conjunction with surgical procedures 4

Important Considerations

• Antegrade stenting is often performed 1-2 weeks after initial PCN placement in non-emergent cases 1
• In cases of severe infection or bleeding, JJ-stent insertion may be contraindicated until adequate drainage is established via PCN 3
• Lower urinary tract dysfunction should be excluded before stent placement 3
• Regular stent surveillance with scheduled exchanges is mandatory to prevent encrustation and obstruction 3
• The routine check nephrostogram following antegrade stent placement may not be necessary in all cases 5

Special Techniques

• For optimal positioning of the proximal pigtail in the renal pelvis, the distal end of the sheath can be used to hold a large portion of the pigtail in the extended state prior to deployment 6
• In laparoscopic settings, antegrade stenting can be performed after completing the posterior suture line, which provides better visualization of the ureteral lumen 4

Antegrade ureteral stenting represents an excellent alternative when retrograde approaches fail or are contraindicated, with high technical success rates and acceptable complication profiles.