What is the treatment approach for symptomatic ureteropelvic junction obstruction (UPJO) using reduction pyeloplasty?

Management of Symptomatic Ureteropelvic Junction Obstruction (UPJO) Using Reduction Pyeloplasty

Laparoscopic dismembered pyeloplasty (Anderson-Hynes technique) is the preferred surgical approach for symptomatic UPJO, especially in cases with extremely distended renal pelvis requiring reduction. 1

Diagnosis and Evaluation

• Imaging Assessment:

  • CT scan with contrast and delayed images for accurate anatomical assessment 1
  • Diuretic renogram (MAG3 preferred over DTPA) to evaluate:
    • Split renal function (differential renal function)
    • Urinary tract drainage based on renal washout curves 2
    • T1/2 of time activity curve (T1/2 >20 minutes indicates obstruction) 2

• Indications for Surgical Intervention:

  • Decreased renal function (<40% differential renal function)
  • Deteriorating function (>5% change on consecutive renal scans)
  • Worsening drainage on serial imaging 2
  • Symptomatic obstruction (flank pain, recurrent UTIs)

Surgical Approach Selection

1. Laparoscopic Pyeloplasty (First-line):

   • Success rate approaching 100% 1
   • Indicated for:
     • Crossing vessels
     • Extremely distended renal pelvis requiring reduction
     • Long strictures
     • Failed previous repairs 1

2. Open Pyeloplasty:

   • Reserved for complex cases with specific anatomical abnormalities requiring reconstruction 1
   • Better visualization in cases with severe peripelvic fibrosis

3. Endopyelotomy:

   • Lower success rates compared to pyeloplasty (78.26% vs 100%) 3
   • Not recommended as first-line for severely dilated renal pelvis

Special Considerations for Low-Functioning Kidneys

• For kidneys with DRF <20%:

  • Pyeloplasty is still effective and safe, not associated with higher complication rates compared to nephrectomy 4
  • Approximately 36% of patients show functional recovery >5% after pyeloplasty 4
  • Postnatal diagnosis is associated with higher chance of functional recovery 4

• For kidneys with DRF ≤10%:

  • Pyeloplasty remains a viable option with no difference in failure rates compared to kidneys with better function 5
  • DRF alone should not dictate management options 5

Intraoperative and Postoperative Management

• Surgical Technique for Reduction Pyeloplasty:

  • Excision of redundant renal pelvis
  • Dismembered pyeloplasty with spatulation of the ureter
  • Watertight anastomosis
  • Placement of ureteral stent for drainage

• Perioperative Care:

  • Antimicrobial prophylaxis prior to intervention 1
  • Safety guidewire during procedure to prevent complications 1
  • If purulent urine is encountered, abort procedure and establish drainage 1

Follow-up Protocol

• Diuretic renogram at 3-6 months post-procedure 1
• Ultrasound to assess resolution of hydronephrosis
• Monitor for symptom resolution
• Long-term follow-up to detect recurrent obstruction 1

Management of Recurrent UPJO

• Recurrence rates of 2.5%-10% after primary pyeloplasty 6

• Main causes of recurrence:

  • Severe peripelvic and periureteric fibrosis
  • Ureteral ischemia
  • Inadequate hemostasis
  • Undiagnosed lower pole crossing vessels 6

• Re-do pyeloplasty has high success rates and rare complications compared to other secondary interventions 6

• Laparoscopic approach for re-do pyeloplasty shows good outcomes with benefits of minimally invasive surgery 7

Pitfalls and Caveats

• Poor preoperative renal function alone should not be a contraindication to pyeloplasty 5, 4
• Failure to identify crossing vessels can lead to recurrent obstruction 6
• Careful hemostasis is essential to prevent fibrosis and recurrence 6
• In pediatric cases with UTD P3 (severe hydronephrosis), consider antibiotic prophylaxis to prevent UTIs 2