What is the recommended treatment for a patient with symptomatic ureteropelvic junction obstruction (UPJO) who has failed conservative management, and is Anderson-Hynes pyeloplasty a suitable option?

Anderson-Hynes Pyeloplasty for Ureteropelvic Junction Obstruction

Anderson-Hynes dismembered pyeloplasty remains the gold standard surgical treatment for symptomatic ureteropelvic junction obstruction (UPJO) that has failed conservative management, with success rates exceeding 90% even in long-term follow-up. 1

When to Proceed with Anderson-Hynes Pyeloplasty

Primary Indications

• Symptomatic UPJO with persistent flank pain, recurrent urinary tract infections, or declining renal function warrants surgical intervention. 2
• Obstructive pattern on functional renal scan (T1/2 >20 minutes on MAG3 or DTPA scan) indicates need for pyeloplasty. 3
• Progressive deterioration in differential renal function (>5% decline on consecutive renal scans) requires surgical correction. 3

Conservative Management First

• Initial management should include ureteral stenting to relieve obstruction before definitive pyeloplasty, particularly in acute presentations. 4
• If stenting fails due to complete obstruction, place percutaneous nephrostomy for temporary drainage prior to definitive repair. 4, 5

Surgical Approach and Technique

Standard Procedure

• Anderson-Hynes dismembered pyeloplasty involves complete excision of the obstructed UPJ segment with spatulated reanastomosis of the ureter to the renal pelvis. 6, 1
• The procedure can be performed via open, laparoscopic, or robotic approaches with equivalent success rates. 7, 8

Internal Stenting Controversy

• While some advocate routine double-J stent placement to protect the anastomosis, adequate spatulation and watertight anastomosis may eliminate the need for internal stenting in uncomplicated cases. 6
• However, most contemporary guidelines recommend stent placement after ureteral repair to reduce failures and strictures. 3
• The trade-off is that internal stents cause higher rates of catheter-related urinary symptoms and flank pain. 6

Special Consideration: Poorly Functioning Kidneys

When Differential Renal Function is Low (≤20%)

• Pyeloplasty is safe and effective even in kidneys with differential renal function (DRF) ≤10%, with no increased complication or failure rates compared to better-functioning kidneys. 2
• Low preoperative DRF alone should not dictate management—pyeloplasty prevents further functional loss and relieves symptoms in most cases. 2, 8
• Approximately one-third of patients with DRF <20% will show functional recovery >5% after pyeloplasty, particularly those with postnatal diagnosis. 7
• Nephrectomy should be reserved for truly non-functioning kidneys or when pyeloplasty fails, as deferred nephrectomy is rarely needed after successful decompression. 7

Pyeloplasty vs. Nephrectomy Decision Algorithm

• For DRF 10-20%: Pyeloplasty is preferred as it provides equivalent symptom resolution to nephrectomy while preserving renal tissue. 8
• For DRF <10%: Consider pyeloplasty if the patient is symptomatic and desires organ preservation, as complication rates are not higher than nephrectomy. 2
• Nephrectomy may be chosen for asymptomatic patients with DRF <10% who prefer less intensive follow-up, as it requires fewer postoperative visits. 7

Expected Outcomes

Success Rates

• Overall success rate for Anderson-Hynes pyeloplasty is 91% across all grades of hydronephrosis. 1
• Success rates reach 93-100% for grades I-III hydronephrosis but drop to 62.5% for grade IV hydronephrosis with renal function <25%. 1
• Failure occurs within the first 3 months in 57% of cases and during long-term follow-up in 43%. 1

Functional Recovery

• Pyelocaliceal volume returns to normal in 22% of patients and significantly decreases in 46%. 1
• Mean eGFR increases by approximately 6 mL/min/1.73m² after pyeloplasty in poorly functioning kidneys. 8

Common Pitfalls to Avoid

• Do not automatically recommend nephrectomy for low-functioning kidneys—DRF alone is not predictive of pyeloplasty failure. 2
• Ensure adequate spatulation and hemostasis during anastomosis, as this is more critical to success than routine stent placement. 6
• Monitor closely in the first 3 months postoperatively, as this is when most failures occur. 1
• In patients with urinary diversion (ileal conduit), avoid internal double-J stents as they occlude quickly from mucous plugging—use percutaneous nephroureteral stents instead. 9