What is the primary treatment for uteropelvic junction (UPJ) obstruction?

Primary Treatment for Ureteropelvic Junction Obstruction

Laparoscopic dismembered pyeloplasty (Anderson-Hynes technique) should be the first-line treatment for ureteropelvic junction (UPJ) obstruction due to its high success rate approaching 100% and favorable morbidity profile. 1

Diagnosis and Evaluation

Before proceeding with treatment, proper diagnostic evaluation is essential:

• CT scan with contrast and delayed images to assess anatomy and degree of obstruction
• Diuretic renogram to evaluate renal function and severity of obstruction
• Assessment of factors including:
  • Severity of symptoms (flank pain)
  • Renal function
  • Anatomical considerations (crossing vessels, distended renal pelvis)
  • Patient-specific factors

Treatment Algorithm

First-Line Treatment

• Laparoscopic pyeloplasty is the gold standard treatment for UPJ obstruction 1
  • Particularly indicated for cases with crossing vessels, extremely distended renal pelvis, long strictures, or failed previous repairs
  • Both retroperitoneal and transperitoneal approaches show comparable success rates 2

Alternative Approaches

• Endopyelotomy may be considered in select cases, but has lower success rates (81-89%) compared to pyeloplasty 3

  • Less effective for patients with:
    • Large pyelocaliceal volumes (>50 ml)
    • Poor renal function
    • Crossing vessels at the UPJ

• Open pyeloplasty should not be first-line for most patients unless specific anatomical abnormalities require reconstruction 1

Special Circumstances

• In cases of pyonephrosis/infection with UPJ obstruction:
  • Immediate decompression via percutaneous nephrostomy (PCN) or retrograde ureteral stenting is required before definitive treatment 4
  • Antibiotics alone are insufficient for treating acute obstructive pyelonephritis 4

Management of Recurrent UPJ Obstruction

If initial pyeloplasty fails (occurs in 2.5-10% of cases) 2:

• Re-do pyeloplasty is considered the gold standard for secondary therapy 2
  • Success rates for re-do procedures are high (94.6%) 5
  • Can be performed via open, laparoscopic, or robot-assisted approaches

Important Considerations and Pitfalls

• Always rule out concurrent ureterovesical junction obstruction before performing pyeloplasty

  • Retrograde pyelography is valuable for identifying concurrent distal ureteral obstruction that might be missed on standard imaging 6

• Crossing vessels are a common cause of both primary and recurrent UPJ obstruction

  • Failure to identify lower pole crossing vessels is a significant cause of recurrent obstruction 2

• Postoperative monitoring is essential:

  • Diuretic renogram at 3-6 months post-procedure
  • Ultrasound to assess resolution of hydronephrosis
  • Most failures occur within the first 2 years after surgery 2

• Risk factors for pyeloplasty failure include:

  • Poor preoperative split renal function
  • Severe hydronephrosis
  • Presence of renal stones
  • Diabetes
  • Prior endopyelotomy 2

By following this treatment algorithm and being aware of potential pitfalls, the management of UPJ obstruction can achieve excellent outcomes with success rates approaching 100% for primary cases and over 90% for recurrent cases.