Antegrade ureteric stenting

Antegrade ureteric stenting is a medical procedure used to relieve urinary tract obstructions by inserting a stent into the ureter, a tube that carries urine from the kidney to the bladder, via an antegrade approach. 

Indications

Antegrade ureteric stenting is indicated for patients with:

1. Urinary Tract Obstructions: Blockages in the ureter caused by kidney stones, tumours, strictures, or other conditions.
2. Hydronephrosis: Swelling or dilation of the kidney due to backed-up urine caused by an obstruction.
3. Ureteral Injuries or Fistulas: Cases where there is damage or abnormal connections (fistulas) in the ureter requiring internal support.

Procedure

1. Pre-procedure Assessment:
   • Imaging Studies: CT scans, MRI, or ultrasound may be used to identify the location and extent of the ureteric obstruction.
   • Laboratory Tests: Renal function tests, urine analyses, and blood tests to assess kidney function and overall health.
2. Preparation:
   • Informed Consent: Explanation of the procedure, its risks, benefits, and alternatives, followed by obtaining informed consent from the patient.
   • Patient Preparation: The patient may be instructed to fast for several hours before the procedure.
3. Anaesthesia:
   • The procedure is typically performed under local anaesthesia or conscious sedation to minimise discomfort.
4. Access and Guidewire Placement:
   • Using fluoroscopic guidance, a needle is inserted into the kidney (percutaneously) through the skin, usually in the flank region.
   • A guide wire is passed through the needle and advanced down the ureter, beyond the obstruction, and into the bladder.
5. Dilation and Stent Insertion:
   • Over the guide wire, a series of dilators of increasing size are passed to create a pathway (tract) from the skin to the ureter.
   • A ureteric stent, typically made of silicone or polyurethane, is then inserted through the dilated tract and positioned across the obstruction in the ureter.
6. Confirmation and Securement:
   • The position of the stent is confirmed using fluoroscopy or X-ray imaging to ensure proper placement.
   • The stent is secured internally within the ureter using its design or an external loop secured to the skin to prevent migration.
7. Post-procedure Care:
   • The stent facilitates urine flow from the kidney to the bladder, relieving the obstruction and reducing kidney swelling.
   • Patients may experience temporary discomfort or urinary symptoms after the procedure, which usually subside over time.
   • Follow-up appointments are scheduled for stent removal or exchange as needed.

Benefits

• Urinary Drainage: Relieves pressure on the kidney and allows urine to bypass ureteric obstructions, reducing kidney swelling and preserving kidney function.
• Immediate Relief: Rapid improvement in symptoms such as flank pain, urinary retention, or hydronephrosis.
• Maintains Ureteral Patency: Prevents the ureter from collapsing or becoming blocked again, allowing continuous urine flow.
• Minimal Invasiveness: Compared to surgical interventions, antegrade ureteric stenting is minimally invasive with shorter recovery times.

Risks and Considerations

• Stent-related Complications: Potential risks include stent migration, blockage due to encrustation or debris, and stent-related discomfort or urinary symptoms.
• Infection: Risk of infection at the insertion site or within the urinary tract, requiring monitoring and appropriate antibiotic therapy.
• Bleeding or Injury: Minimal risk of bleeding or injury during the procedure, particularly in patients with bleeding disorders or anatomical challenges.
• Stent Exchange or Removal: Stents may need to be exchanged or removed periodically based on clinical indications, which may require additional procedures.

Conclusion

Antegrade ureteric stenting is an effective and minimally invasive procedure for relieving ureteric obstructions, reducing kidney swelling, and restoring urinary flow. It provides immediate relief of symptoms and helps preserve kidney function in cases of hydronephrosis or ureteral injuries. Close monitoring and follow-up care are essential to address any stent-related complications and ensure optimal outcomes for patients undergoing this procedure.