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Indications / Contraindications
Indications
- Ureteral obstruction not amenable to retrograde cystoscopic stenting (malignant extrinsic compression, post-op strictures, fistulas)
- Ureteral strictures — malignant (~2/3 of cases) or benign (surgical, radiation, inflammatory)
- Ureteral fistula/leak — stenting promotes tissue apposition and re-epithelialization
- Failed retrograde stent placement (antegrade rendezvous technique)
- Relief of urinary obstruction while definitive treatment is planned
Contraindications
- Same as nephrostomy: uncorrectable coagulopathy (INR <1.5, Plt >50K target)
- In malignant obstruction: life expectancy must justify procedure risks and ongoing stent management burden
- No safe renal access window (rare — consider nephrostomy first, then internalize)
Clinical Note
Always obtain the cystoscopy/retrograde attempt report. Knowing exactly where the retrograde failed guides your antegrade strategy.
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Pre-Procedure Checklist
Review CT for ureteral anatomy. Identify location and length of obstruction, crossing vessels, ureteral course, and any prior surgical anatomy. Note distance from UPJ to obstruction.
Retrograde attempt history. Obtain cystoscopy report if retrograde was tried. Note where the wire failed — this guides antegrade wire strategy.
Labs. CBC, BMP, coagulation panel (INR, PTT, Plt). Target INR <1.5, Plt >50K.
Antibiotics. Ceftriaxone 1g IV 1h before procedure. Mandatory — same infectious risk as nephrostomy.
NPO. Minimum 4–6h (moderate sedation).
Stent sizing. Standard 6–7 Fr, 24–28 cm. Measure ureter length on CT for correct size — measure from UPJ to UVJ.
Urology co-management. Antegrade stenting requires close urologic follow-up for stent exchange every 3–6 months. Confirm urology is aware and follow-up is arranged.
Consent. Ureteral injury, stent migration, infection, failure to traverse obstruction, need for ongoing stent exchanges, bladder irritation symptoms from distal stent coil.
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Relevant Anatomy
Ureteral Course
- Total length: ~28–30 cm from renal pelvis to bladder
- Three natural narrowings: UPJ (ureteropelvic junction), iliac vessel crossing, UVJ (ureterovesical junction) — most obstruction at UPJ or UVJ
- Upper ureter: Posterior to peritoneum, courses medially toward spine. Left ureter crosses aorta; right ureter crosses IVC
- Mid ureter: At L3–L5, courses lateral to psoas muscle
- Distal ureter: Crosses iliac vessels (R: external iliac; L: common iliac), enters pelvis toward bladder
Vascular Supply & Clinical Relevance
- Proximal ureter: Renal artery branches
- Mid ureter: Gonadal artery
- Distal ureter: Superior vesical artery
- Rich anastomotic collateral supply — but disruption from surgery causes ischemic strictures that are very difficult to dilate durably
- Medial blood supply: For the upper ureter, vessels approach from the medial side — stay lateral when possible to preserve supply
- Ischemic strictures at surgical anastomoses: notoriously resistant to balloon dilation, especially if >3 months old
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Technique
Default RadCall approach · share your own below
Supplies
Ultrasound + sterile probe cover
C-arm fluoroscopy
ChloraPrep
Sterile drape
1% lidocaine
21G Chiba needle (trocar)
0.018-inch guidewire (in AccuStick set)
AccuStick introducer set
0.035-inch x 145 cm Amplatz super-stiff wire
0.035-inch x 145 cm Hydrophilic angled wire (Glidewire)
4–5 Fr x 45 cm Kumpe catheter
6 Fr ureteral access sheath (optional)
Double-J stent (6 Fr × 24–28 cm)
Pusher catheter (in most kits)
Contrast + syringes
Foley catheter (optional — bladder delineation)
Steps
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Percutaneous renal access
Same as nephrostomy — obtain access to collecting system via posterior lower pole calyx. Establish 0.035-inch wire access coiled in renal pelvis. See nephrostomy playbook for detailed access technique.
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Antegrade pyelogram
Inject contrast to delineate anatomy and identify level/extent of obstruction. In tight obstructions, a standing column of contrast won't pass — use angiographic catheter for selective injection adjacent to the stricture.
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Traverse the obstruction
Kumpe catheter + hydrophilic Glidewire combination. Work the wire through the obstruction with gentle rotation and advancement. Confirm wire in bladder under fluoroscopy — wire coils or straightens depending on bladder fill. Do not force a tight obstruction without a plan.
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Bladder confirmation
Instill contrast retrograde via Foley catheter to opacify bladder for wire position confirmation (if Foley in place). Alternatively, AP pelvis fluoroscopy will show wire coiling freely in bladder. Do not place the stent until bladder position is confirmed.
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Measure ureteral length
Advance a 5 Fr catheter into the bladder to the pubic symphysis. Mark catheter at skin. Pull back catheter to the renal pelvis. Mark at skin. Measure this distance = ureteral length. Select appropriately sized stent: 22–26 cm → most adults; 28–30 cm → tall patients / long ureters; 20–22 cm → smaller patients.
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Stent placement
Exchange hydrophilic wire for Amplatz. Load double-J stent over wire on pusher catheter. Advance stent over wire under fluoroscopy. Verify proximal coil in renal pelvis and distal coil in bladder. Use pusher to advance while holding wire steady.
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Remove wire through stent
Withdraw pusher catheter while holding wire steady; then withdraw wire through the stent. Confirm both pigtails (renal pelvis and bladder) on fluoroscopy before removing wire.
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External drain decision
If traversal was complex or obstruction very tight, consider leaving a nephrostomy tube alongside the stent for 48–72h for drain monitoring and tract maturation. Remove external drain at follow-up nephrostogram once stent patency is confirmed.
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Troubleshooting
Problem
Cannot traverse obstruction antegrade
Likely cause: Complete occlusion, heavily encased malignant stricture, or angulated anatomy preventing wire passage.
Next step: Antegrade rendezvous technique — simultaneous cystoscopy with antegrade access. Urologist introduces wire retrograde through cystoscope; IR snares the wire antegrade, creating a through-and-through track. Then load stent from below or above.
Problem
Malignant obstruction — tight extrinsic compression
Likely cause: Extrinsic compression by tumor prevents stent from maintaining lumen patency.
Next step: Balloon dilation of stricture first (6–8 mm angioplasty balloon), then stent placement. Consider metallic ureteral stent (Resonance metallic stent) for durable patency in malignancy — better long-term patency than plastic double-J.
Problem
Stent migration — proximal coil not in pelvis
Likely cause: Stent pulled distally during wire removal, or undersized stent.
Next step: KUB confirms coil not in pelvis. Return to IR — reaccess via nephrostomy tract, snare stent under fluoroscopy, and reposition or replace with a longer stent. Consider measuring ureter length more carefully on CT before repeat attempt.
Problem
Persistent obstruction after stent placement
Likely cause: Stent kinked, malpositioned, encrusted, or obstruction progressed.
Next step: Contrast nephrostogram to confirm stent patent and not kinked. Rule out bilateral involvement. Consider leaving nephrostomy tube alongside stent. If stent patent but obstruction persists, consider upsizing or switching to metallic stent.
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Complications
Immediate
- Ureteral injury during wire traversal — perforation, avulsion (rare but devastating)
- Gross hematuria — common short-term from access; should resolve within 24–48h
- Infection/sepsis — prophylactic antibiotics mandatory; same risk as nephrostomy
- Failure to traverse — unable to cross obstruction; leave PCN tube, plan rendezvous
Delayed
- Stent occlusion/encrustation — most common long-term complication; every 3–6 month exchange required
- Stent migration — proximal or distal; requires repositioning under fluoroscopy
- Vesicoureteral reflux — intrinsic to internal stenting; flank pain with voiding is expected
- Bladder irritation — frequency, urgency from distal stent coil in bladder — NORMAL; reassure patient
- Ischemic ureteral necrosis — rare; from devascularization combined with instrumentation
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Post-Procedure Care
Monitoring & Imaging
- KUB within 24h to confirm stent position
- Vitals q30 min × 1–2h post-procedure
- Monitor urine output — early stent function indicates successful placement
- If nephrostomy tube left in place: nephrostogram at 48–72h before removing external drain
Patient Expectations & Follow-up
- Expected symptoms: flank pain on voiding (stent reflux), urinary urgency/frequency from distal coil in bladder — these are NORMAL with internal ureteral stents
- Stent exchange: Every 3–6 months (malignant), or 12 months (benign) to prevent encrustation
- Urology follow-up: Coordinate for long-term stent management, definitive surgery, or metallic stent conversion
- When to call IR/ED: severe flank pain, fever, inability to void, significant hematuria
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Critical Pearls
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Two-thirds of antegrade ureteral stents are for malignant obstruction. Set patient expectations appropriately regarding ongoing stent exchanges and the palliative nature of the procedure in this context.
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Ischemic strictures are notoriously difficult. Post-surgical anastomotic ischemic strictures have only 15% durable success at 1 year if the stricture is more than 1 year old. Counsel patients about the low success rate of balloon dilation before proceeding.
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Antegrade rendezvous is your escape valve. When you cannot cross an obstruction alone from above, coordinate simultaneous cystoscopy. The through-and-through wire technique solves the majority of otherwise impassable obstructions.
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Short benign strictures have good outcomes. Strictures <2 cm that are <3 months old have ~88% balloon dilation success. Patient selection matters — early intervention for benign ischemic strictures while they are still soft and short.
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Metallic stents for malignancy. Resonance metallic stents offer better long-term patency vs. plastic double-J in malignant obstruction. Consider upfront metallic stenting in patients with expected survival >3–6 months to reduce exchange burden.
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Always confirm both coils before removing the wire. Once the wire is out, repositioning the stent requires a new access procedure. Take the extra 30 seconds to confirm proximal coil in pelvis and distal coil in bladder on fluoroscopy before withdrawing the wire.
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Stent Exchange Protocol
Exchange Schedule
- Standard plastic double-J: Every 3–6 months (malignant obstruction)
- Benign stricture: Every 12 months or when symptomatic
- Metallic stent (Resonance): Every 6–12 months; may have longer durability depending on manufacturer recommendation
- Exchange earlier if: Flank pain, fever, rising creatinine, decreased urine output from affected side
Signs of Stent Failure
- Flank pain — obstruction or reflux
- Fever / urinary tract infection — occluded stent with infected urine
- Rising serum creatinine — loss of drainage
- Decreased urine output from affected side (if monitored)
- KUB shows stent not spanning UPJ to bladder — migration
- Encrustation: Mineral deposits on stent — more common with prolonged indwelling and dehydration
Exchange Technique
| Approach | Preferred For | Notes |
|---|---|---|
| Retrograde (cystoscopy) | Standard exchange — preferred approach | Done by urology; no new renal access needed |
| Antegrade (IR) | When retrograde not possible (pelvic anatomy, prior diversion, inaccessible UVJ) | Same technique as initial placement |
| Metallic stent exchange | Malignant obstruction with prior plastic stent failure | Requires larger access sheath; coordinate with urology |
Encrustation Prevention
- Adequate hydration (goal urine output >2 L/day) — reduces crystal precipitation on stent surface
- Citrate supplementation (potassium citrate) in select patients with stone-forming risk
- Strict exchange schedule — encrustation increases exponentially after 6–12 months
- Heavily encrusted stents: may require ureteroscopic laser lithotripsy for removal — involve urology early
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References & Resources
Primary sources · Key data · Related procedures
Key Guidelines
- EAU guidelines on ureteral stenting
- SIR quality improvement guidelines for ureteral interventions
Primary References
- Liatsikos E, Kallidonis P, Kyriazis I, et al. Ureteral obstruction: is the full metallic double-pigtail stent the way to go? Eur Urol. 2010;57(3):480–486.
- Borin JF. Ureteral stenting: past, present, and future. Curr Urol Rep. 2008;9(2):99–104.
- Chung SY, Stein RJ, Landsittel D, et al. 15-year experience with the management of extrinsic ureteral obstruction with indwelling ureteral stents. J Urol. 2004;172(2):592–595.