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Prof. Dr. Ali Avanoğlu
UPJ Obstruction • After surgery and follow-up

If the Narrowing Comes Back After Surgery: Redo Pyeloplasty

Pyeloplasty is a single, lasting operation for most children; but in a small group, the narrowing comes back. This page explains why recurrent UPJ obstruction happens, how it's recognized, and which options exist — redo (repeat) pyeloplasty chief among them.

Who this is forFamilies of children whose follow-up after pyeloplasty shows increasing widening, pain or infection, or who have been told "the surgery didn't hold"
Reading≈5 min
ByProf. Dr. Ali AvanoğluUpdated
This page is part of UPJ obstruction.Read the full treatment overview on the hub page
scar tissuerenewed narrowingBEFORE: scar and renewed narrowing at the old junctionRECURRENT UPJ OBSTRUCTIONwide funnel sutureJJ stent (4–6 weeks)urine flows freelynew anastomosis · outside scar tissueAFTER: scar removed, new wide junctionREDO PYELOPLASTY
scar tissuerenewed narrowingBEFORE: scar and renewed narrowing at the old junctionRECURRENT UPJ OBSTRUCTIONwide funnel sutureJJ stent (4–6 weeks)urine flows freelynew anastomosis · outside scar tissueAFTER: scar removed, new wide junctionREDO PYELOPLASTY
redo pyeloplasty: scarred junction → new wide anastomosis
01 · How often it happens, and when it shows up02 · Why the narrowing recurs03 · How it's recognized: the steps of evaluation04 · Options: redo pyeloplasty, endoscopic methods, ureterocalicostomy05 · Decision and follow-up: the same team, at any age
In brief5 madde
  • How often it happens, and when it shows up: The success of Anderson–Hynes (dismembered) pyeloplasty is given in guidelines as roughly 90–95% and above; the need for a repeat procedure is roughly 3–5%.
  • Why the narrowing recurs: The most common cause is excessive scar tissue forming at the suture line; children who had a urine leak or infection carry a slightly higher risk of scarring.
  • How it's recognized: the steps of evaluation: Suspicion usually begins during follow-up: the widening increasing rather than decreasing on successive ultrasounds, new-onset flank pain or episodes of vomiting, a…
  • Options: redo pyeloplasty, endoscopic methods, ureterocalicostomy: Redo pyeloplasty means removing the scarred junction again and re-joining a healthy ureter to the renal pelvis; it can be done open, laparoscopically, or robotically.
  • Decision and follow-up: the same team, at any age: The decision is based on the child's age, symptoms, the course of function, and the length and anatomy of the narrowing.
01

How often it happens, and when it shows up

The success of Anderson–Hynes (dismembered) pyeloplasty is given in guidelines as roughly 90–95% and above; the need for a repeat procedure is roughly 3–5%. This figure is similar regardless of approach (open, laparoscopic, robotic).

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  • Most failures show up in the first 1–2 years, which is why follow-up is more frequent during that period. Later recurrence is rarer but possible, and can show up especially during the adolescent growth spurt or with pain in adulthood.
  • A recurrent narrowing is not a "failed operation" label — it's a fixable situation. Redo pyeloplasty success is reported at roughly 85–95% in the literature; in other words, the second repair is also very likely to give a lasting result.
02

Why the narrowing recurs

The most common cause is excessive scar tissue forming at the suture line; children who had a urine leak or infection carry a slightly higher risk of scarring. Tension at the suture line, a ureter end with compromised blood supply, or a long narrow segment can also affect healing.

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  • Other causes include a crossing vessel missed at the first operation, the ureter being reattached to the renal pelvis at a high, non-dependent point (letting urine pool in the pelvis), and an overly widened pelvis that wasn't reduced enough.
  • Sometimes the issue isn't narrowing at all but the appearance of poor emptying: a very widened pelvis can drain slowly on MAG3 through a "reservoir" effect without any true obstruction. Making this distinction is the foundation of the redo decision, and it isn't made from the drainage curve alone.
03

How it's recognized: the steps of evaluation

Suspicion usually begins during follow-up: the widening increasing rather than decreasing on successive ultrasounds, new-onset flank pain or episodes of vomiting, a febrile urinary tract infection, or a drop in function on MAG3. A single ultrasound number doesn't settle it — the course matters.

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  • Evaluation starts by repeating ultrasound and MAG3 diuretic renography: split (renal) function is compared with previous measurements, a drop of more than 10 points on serial measurement is considered meaningful, and the drainage curve is read together with function and hydration.
  • MR urography (contrast-enhanced MR showing anatomy and function) is a valuable tool for seeing the anatomy: the length of the narrowing, a crossing vessel, and the shape of the renal pelvis can be seen. If needed, retrograde pyelography (contrast given through the ureter during surgery) can pin down the exact location and length of the narrowing. This information determines which approach is suitable.
04

Options: redo pyeloplasty, endoscopic methods, ureterocalicostomy

Redo pyeloplasty means removing the scarred junction again and re-joining a healthy ureter to the renal pelvis; it can be done open, laparoscopically, or robotically. Success in children and adults is reported at roughly 85–95%, and it's the first choice at most centers. Because of scarring, the operation can be technically harder than the first one, which is why it's planned by an experienced team through the joint assessment of two specialists.

  • Redo pyeloplasty (open / laparoscopic / robotic): first choice; roughly 85–95% success.
  • Endopyelotomy or balloon dilation: short narrowing, good function, a selected case; lower success.
  • Ureterocalicostomy: a small intrarenal pelvis or severe scarring.
  • Temporary nephrostomy: draining an infected or very widened kidney first, followed by a planned repair.
  • Nephrectomy: a rare option for a kidney with very low function that is causing symptoms.
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  • Endoscopic methods such as endopyelotomy and balloon dilation can be considered for short, thin narrowings with preserved function in selected cases; success is lower than redo pyeloplasty (roughly 40–70% in the literature).
  • If the renal pelvis is small and stays within the kidney, or scarring is severe, ureterocalicostomy (joining the ureter directly to the lowest calyx) can be chosen. Nephrectomy — removing the kidney — is a rare option that only comes up for a kidney with very low function that is also causing symptoms.
05

Decision and follow-up: the same team, at any age

The decision is based on the child's age, symptoms, the course of function, and the length and anatomy of the narrowing. In a child who is symptom-free, with stable function and no increasing widening, close monitoring alone is sometimes enough; if there's pain, infection or a loss of function, repair is not delayed.

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  • Follow-up after a redo proceeds as it did after the first operation: ultrasound around month 3, then every 6–12 months; MAG3 is repeated if the widening increases or symptoms appear. The renal pelvis, if it remains widened, is expected to improve slowly here as well.
  • A narrowing repaired in childhood recurring in adolescence or adulthood is a separate topic; because we also have adult urology in-house, the adolescent-to-adult transition and redo pyeloplasty in adults are handled by the same team.
UPJ Obstruction video guide3 short videos, in order
Frequently asked questions
If pyeloplasty fails, is the kidney lost?
No, not in the large majority of cases. A recurrent narrowing is usually caught early during follow-up and corrected with redo pyeloplasty, with roughly 85–95% success. Nephrectomy is a rare option that only comes up for a kidney with very low function that is causing symptoms.
If the hydronephrosis hasn't increased at a check-up but hasn't gone away either, does that mean the surgery didn't hold?
No. The widening isn't expected to disappear completely; a decrease or a stable state, the child being symptom-free, and preserved function together count as success. Suspicion of recurrence arises from an increase in widening, a drop in function, or symptoms.
Is redo pyeloplasty harder than the first operation?
It can be technically more demanding because of scar tissue, which is why planning is done with MR urography and an experienced team is preferred. Success rates remain high, and it can still be done open, laparoscopically, or robotically.
Is a closed (endoscopic) method enough for a recurrent narrowing?
It can be considered for short, thin narrowings in selected cases with good function; but success is lower than redo pyeloplasty. If there's a crossing vessel, a long narrowing, or severe hydronephrosis, pyeloplasty is preferred.
←Previous • After surgery and follow-upPyeloplasty ComplicationsNext • After surgery and follow-upEndoscopic Methods→
Related pagesFull index →
After surgery and follow-upEndoscopic MethodsEndopyelotomy and balloon dilation are endoscopic methods that widen UPJ obstruction from the inside, using thin instruments passed through the urinary tract or the skin, without an incision. Because their success is lower than pyeloplasty's, they aren't for everyone — they're used in selected cases, especially adults and older children who've already had surgery.After surgery and follow-upFollow-Up After PyeloplastyFollow-up after pyeloplasty answers more than just "has the hydronephrosis gone away?" Ultrasound tracks the widening's course, and MAG3 tracks function and drainage when needed; a slow improvement in kidney swelling is expected, and success is defined by the overall course, not a single measurement.By age, and special situationsRedo Pyeloplasty in AdultsPyeloplasty performed in childhood lasts a lifetime for the large majority; in a small number of people the narrowing becomes symptomatic again years later. This page explains how recurrent UPJ obstruction is evaluated in adults, and the redo (repeat) repair options.Diagnosis and evaluationMR Urography in Children: When Is It Needed, What Does It Show?MR urography is a contrast-enhanced MRI scan that shows the detailed anatomy of the kidneys and urinary tract, along with function, in the same session. It is not routine for suspected UPJ obstruction; it comes into play for selected questions that ultrasound and MAG3 cannot answer. This page explains when it's needed, how it's done, and its limits.
UPJ Obstruction topic clustersMain treatment page →
Basics 7Diagnosis and evaluation 6Follow-up or surgery? 7Conservative follow-up 5Pyeloplasty and approaches 7After surgery and follow-up 6By age, and special situations 7
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