What is pyeloplasty?

Pyeloplasty: Surgical Management of Ureteropelvic Junction Obstruction

Pyeloplasty is a surgical procedure performed to correct ureteropelvic junction (UPJ) obstruction, which is characterized by a functionally significant impairment of urinary transport between the renal pelvis and ureter, typically resulting in hydronephrosis and potential kidney damage if left untreated. 1

Definition and Indications

Pyeloplasty involves surgical reconstruction of the renal pelvis and ureter junction to restore proper urinary drainage from the kidney. The primary indications include:

• Symptomatic UPJ obstruction (flank pain, recurrent infections)
• Progressive hydronephrosis on imaging
• Decreasing renal function in the affected kidney
• Recurrent pyelonephritis due to obstruction

Types of Pyeloplasty Procedures

1. Dismembered Anderson-Hynes Pyeloplasty:

   • Most commonly performed technique
   • Complete transection of the UPJ with excision of the narrowed segment
   • Spatulation of the ureter and reattachment to the renal pelvis
   • Allows for reduction of redundant renal pelvis
   • Ideal for most UPJ obstructions, especially with crossing vessels

2. Non-dismembered Techniques:

   • Fenger plasty (longitudinal incision and transverse closure)
   • Y-V plasty (for high ureteral insertion)
   • Foley Y-plasty (for significant redundant pelvis)
   • Bypass pyeloplasty (side-to-side anastomosis between ureter and lower renal pelvis) 2

Surgical Approaches

1. Open Pyeloplasty

• Traditional approach with high success rates (>90%)
• Requires larger incision with associated morbidity
• Longer hospital stay and recovery time
• Still considered in complex cases or when minimally invasive expertise is unavailable

2. Laparoscopic Pyeloplasty

• Minimally invasive approach that mirrors open surgical techniques
• Transperitoneal or retroperitoneal approach
• Benefits include:
  • Decreased postoperative pain
  • Shorter hospital stay (average 1-2 days)
  • Faster recovery
  • Smaller incisions with better cosmetic results
• Success rates comparable to open surgery (90-95%) 3, 4
• Can be successfully used for secondary UPJ obstruction after failed open surgery 5

3. Robotic-Assisted Laparoscopic Pyeloplasty

• Enhanced visualization and dexterity compared to standard laparoscopy
• Facilitates precise suturing and reconstruction
• Similar outcomes to laparoscopic approach with potentially shorter learning curve

Perioperative Management

Preoperative Assessment

• Imaging studies to confirm diagnosis and assess anatomy:
  • Ultrasonography (first-line for confirming pelvocaliectasis)
  • CT scan or MRI (to determine underlying etiology)
  • Diuretic renography (to assess functional obstruction)
• Renal function tests to evaluate kidney function 6

Intraoperative Considerations

• Ureteral stent placement (typically 4-6 weeks)
• Identification and management of crossing vessels (present in approximately 50% of cases) 3
• Watertight anastomosis to prevent urine leakage
• Drain placement to monitor for postoperative leakage

Postoperative Care

• Pain management with minimal opioid use (0-15 oxycodone 5mg tablets or equivalent) 7
• Early ambulation and resumption of oral intake
• Monitoring for complications:
  • Urine leak (1-5%)
  • Anastomotic stricture (2-5%)
  • Persistent obstruction
• Stent removal typically at 4-6 weeks postoperatively

Outcomes and Follow-up

• Success rates of 90-98% for primary pyeloplasty 4
• Lower success rates (80%) for secondary or complex repairs 4
• Follow-up evaluation:
  • Serial ultrasound examinations to assess resolution of hydronephrosis
  • Diuretic renography at 3-6 months to confirm resolution of obstruction
  • Renal function tests to monitor kidney function 6

Special Considerations

• Secondary UPJ Obstruction: Laparoscopic pyeloplasty can be effective after failed open surgery with success rates of approximately 80% 5
• Bilateral UPJ Obstruction: Can be addressed in a single procedure or staged approach
• Pediatric Patients: Principles are similar with modifications for smaller anatomy
• Crossing Vessels: Present in approximately 50% of cases and require careful identification and management during surgery 3

Common Pitfalls and Caveats

• Failure to identify crossing vessels can lead to persistent obstruction
• Inadequate spatulation of the ureter may result in anastomotic stricture
• Excessive tension on the anastomosis increases risk of leakage or stricture
• Incomplete excision of pathologic UPJ tissue may lead to recurrent obstruction
• During the COVID-19 pandemic, pyeloplasty was classified as a functional/reconstructive procedure that could be postponed in non-emergency situations 7

Pyeloplasty remains the gold standard for surgical correction of UPJ obstruction with excellent long-term outcomes when performed by experienced surgeons using either open or minimally invasive approaches.