What is the Subureteric Transurethral Injection (STING) procedure after a failed Cohen cross‑trigonal ureteric reimplantation for vesicoureteral reflux?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 22, 2026 • View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

STING Procedure After Failed Cohen Ureteric Reimplantation

Endoscopic subureteric injection (STING) is a highly effective and recommended salvage procedure after failed Cohen cross-trigonal ureteric reimplantation, with success rates of 67.5-87.5% after one or two injections in this specific clinical scenario. 1

Primary Management Approach

STING should be the first-line intervention for persistent vesicoureteral reflux (VUR) following failed Cohen reimplantation. 1 The procedure involves:

  • Subureteric injection technique using either dextranomer/hyaluronic acid (Dx/HA; Deflux) or polyacrylate-polyalcohol copolymer (PPC; Vantris) as bulking agents 2
  • Endpoint of injection: Loss of hydrodistention of the ureteral orifice 3
  • Outpatient day-care procedure with minimal morbidity and rapid recovery 4, 1

Expected Success Rates in Failed Reimplantation

The evidence specifically addressing STING after failed open reimplantation demonstrates:

  • 67.5% success rate (27/40 ureters) after a single STING injection 1
  • Additional 17.5% success (7/40 ureters) after a second injection 1
  • Overall 87.5% success rate (34/40 ureters) after one or two injections 1
  • Only 5% ultimate failure rate (2/40 ureters) requiring repeat open surgery 1

Technical Considerations

Injection Technique Selection

  • Subureteric technique (STING) is the standard approach for failed reimplantation 1
  • Intraureteric hydrodistention technique may be used in complex anatomy, particularly with duplex systems 3
  • Injection volume: Generally less for PPC than Dx/HA to achieve equivalent success 2

Bulking Agent Choice

  • Dextranomer/hyaluronic acid (Dx/HA) is the most extensively studied agent with proven efficacy 2
  • Small-size Dx/HA (80-120 μm) may offer similar success with lower cost 5
  • Polyacrylate-polyalcohol copolymer (PPC) is an alternative with comparable short-term outcomes 2
  • Avoid polytetrafluoroethylene (PTFE/Teflon) due to particle migration concerns, though historical data used this agent 2, 4, 1

Post-Procedure Management

Mandatory Imaging

  • Renal ultrasound should be obtained to assess for obstruction, as all correction methods can cause ureteral obstruction 2
  • Voiding cystourethrography (VCUG) is recommended at 6 weeks to 3 months post-procedure to confirm reflux resolution 2, 6

Follow-Up Timeline

  • Initial VCUG: 6 weeks to 3 months post-injection 6, 1
  • Long-term surveillance: At 1 year and 3 years 1
  • Annual monitoring: Blood pressure, height/weight, urinalysis for proteinuria and UTI through adolescence if kidneys are abnormal 2

Algorithm for Persistent Reflux After STING

If STING fails after failed Cohen reimplantation:

  1. First STING failure (32.5% of cases): Proceed to second STING injection 1

    • Success rate of second injection: 67% 2

  2. Second STING failure: Consider repeat open ureteral reimplantation 1

    • Alternative technique (e.g., Lich-Gregoir extravesical) may be preferable to repeat Cohen 6
    • Robot-assisted laparoscopic reimplantation (RALUR) is an option in older children with complex anatomy 2

  3. Downgrading to Grade I reflux (observed in 7/14 initial failures): May be managed conservatively with continuous antibiotic prophylaxis (CAP) 1

Critical Pitfalls to Avoid

  • Do not delay STING in symptomatic patients with breakthrough febrile UTIs after failed reimplantation 7
  • Do not assume STING failure precludes successful open surgery: All STING failures in the literature were successfully corrected by subsequent open reimplantation 4, 1
  • Do not ignore bladder and bowel dysfunction (BBD): Success rates are significantly lower (62% vs 74%) in patients with BBD, which must be addressed before or concurrent with STING 2
  • Monitor for late vesicoureteral junction obstruction (VUJO): This complication is more common in patients with BBD and high-grade reflux with dilated ureters 2
  • Assess for recurrence: Two cases of late recurrence after initial STING success have been reported, both successfully treated with repeat STING 4

Advantages Over Immediate Repeat Open Surgery

  • Shorter operative time: Significantly less than repeat open reimplantation 6
  • Minimal postoperative pain: Lower pain scores and analgesic requirements compared to open surgery 6
  • Shorter hospitalization: Outpatient or 1-day stay versus 3-5 days for open surgery 6, 1
  • Lower immediate morbidity: Fewer complications than repeat Cohen procedure 6
  • Does not compromise future open surgery: Failed STING does not preclude successful subsequent reimplantation 4, 1

When to Proceed Directly to Repeat Open Surgery

Consider bypassing STING and proceeding directly to repeat open reimplantation in:

  • Grade V reflux with megaureters requiring ureteral tapering 6
  • Neuropathic bladder: STING success rate drops to 62% versus 95.5% for open Cohen in this population 4
  • Multiple previous STING failures (≥3 injections): Third injection success rate is only 34% 2
  • Patient/family preference for definitive single-stage correction 2

References

2
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

7
Guideline

Management of Recurrent Febrile UTIs in Children

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Related Questions

What is the first‑line therapy for acute group A streptococcal pharyngitis, including dosing for children and adults and alternatives for penicillin allergy?
What is a comprehensive approach to evaluate and treat aggression in a child, covering medical assessment, behavioral interventions, and indications for pharmacotherapy?
How should I manage an adult with acute pancreatitis, pre‑existing hypertension, and skin mottling (early circulatory failure) regarding fluid resuscitation, blood pressure control, analgesia, and monitoring?
What is the appropriate nitrofurantoin dosing for an adult with uncomplicated cystitis, including alternative regimens, prophylaxis, pediatric dosing, and renal function limits?
Why would tofacitinib be started in a patient with hip synovial chondromatosis who has no approved indication for the drug?
Can iron polysaccharide complex be taken concurrently with magnesium glycinate?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question