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Prof. Dr. Ali Avanoğlu
UPJ Obstruction • Pyeloplasty and approaches

Open Pyeloplasty: Repair Through a Small Incision in Infants

Open pyeloplasty is a repair for UPJ obstruction done by reaching the kidney through a small, several-centimeter incision in the flank. It is the standard approach at many centers for infants; this page explains where the incision is placed, how surgery proceeds, recovery, and the scar.

Who this is forFamilies whose baby or young child has been recommended open pyeloplasty and who are wondering "why not the closed method"
Reading≈5 min
ByProf. Dr. Ali AvanoğluUpdated
This page is part of UPJ obstruction.Read the full treatment overview on the hub page
narrow segmentwide pelvisBEFORE: wide pelvis, narrow UPJANDERSON–HYNES · BEFOREwide funnel sutureJJ stent (4–6 weeks)urine flows freelyAFTER: funnel-shaped wide junctionANDERSON–HYNES · AFTEROPEN
narrow segmentwide pelvisBEFORE: wide pelvis, narrow UPJANDERSON–HYNES · BEFOREwide funnel sutureJJ stent (4–6 weeks)urine flows freelyAFTER: funnel-shaped wide junctionANDERSON–HYNES · AFTEROPEN
pyeloplasty before/after; open approach icon (single incision)
01 · What does 'open' pyeloplasty mean?02 · Where is the incision, and how does surgery proceed?03 · Hospital stay, pain, and recovery04 · What does the scar look like?05 · In which child does the open approach stand out?
In brief5 madde
  • What does 'open' pyeloplasty mean?: The word "open" may suggest a large incision, but in children open pyeloplasty is done through a small flank incision.
  • Where is the incision, and how does surgery proceed?: The incision location depends on the surgeon's preference and the kidney's position; two approaches are common in children.
  • Hospital stay, pain, and recovery: The length of stay after open pyeloplasty varies with age and whether a drain is in place; in infants it is usually a few days.
  • What does the scar look like?: One of the most common questions families ask is about the scar; in infants the incision is small and becomes proportionally smaller still as the child grows.
  • In which child does the open approach stand out?: The choice of method depends on center experience; guidelines find the success and complication rates of the three approaches comparable.
01

What does 'open' pyeloplasty mean?

The word "open" may suggest a large incision, but in children open pyeloplasty is done through a small flank incision.

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  • In UPJ obstruction (ureteropelvic junction obstruction; informally, kidney outlet narrowing), the goal is to remove the narrow junction and reattach the ureter to the pelvis; this is the Anderson–Hynes technique, and in open surgery it is performed under direct vision, with direct tissue contact. The longest-standing follow-up data, spanning decades, belongs to this approach.
  • In infants the kidney sits close to the skin and the abdominal wall is thin; this is why a short incision reaches the pelvis and upper ureter easily. The "small-entry" advantage of closed methods is largely offset in infants, whose incision is already small; guidelines note that the open (small-incision) approach is standard at many centers for infants.
02

Where is the incision, and how does surgery proceed?

The incision location depends on the surgeon's preference and the kidney's position; two approaches are common in children.

  • Flank (lumbotomy) incision: on the side, below the lower rib or toward the back, several centimeters long; the muscles are spread rather than cut.
  • Anterior subcostal incision: on the front-side of the abdomen, parallel to the rib margin; can be preferred for a high-positioned kidney or when a crossing vessel is expected.
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  • The peritoneum (abdominal lining) is not opened; the back region where the kidney sits (the retroperitoneum) is entered directly, so there is no contact with the bowel and feeding can start early. The pelvis and ureter are located, a crossing vessel is preserved if present, the narrow segment is removed, and the anastomosis is done with dissolvable sutures. Most surgeons use a JJ (double-J) stent or an externalized stent; a stentless repair can be done in selected cases.
  • The incision is closed in layers with dissolvable sutures; from the outside, usually only a thin strip or skin adhesive is visible.
03

Hospital stay, pain, and recovery

The length of stay after open pyeloplasty varies with age and whether a drain is in place; in infants it is usually a few days.

  • See a doctor: fever (38°C/100.4°F or above), drainage or redness at the wound, increasing pain, vomiting, decreased urine output.
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  • Pain is most noticeable in the first day or two and is well controlled with age-appropriate pain relievers, and at some centers with regional anesthesia (caudal or epidural). Guideline data report slightly more pain and a slightly longer stay with open surgery compared with closed methods; but in infants this difference is small and varies by center.
  • Ordinary care is expected within a few days at home, and full activity within a few weeks. For an older child, your team will give a timeframe for heavy lifting and contact sports. If a JJ stent was placed, it is removed roughly 4–6 weeks later (2–8 weeks depending on the center) under a brief anesthetic via cystoscopy.
04

What does the scar look like?

One of the most common questions families ask is about the scar; in infants the incision is small and becomes proportionally smaller still as the child grows.

  • A thin line remains at the flank or front-side, mostly hidden under clothing. Pink-red at first, it fades within a year. With closed methods, scars are smaller and more scattered; the cosmetic result is noted in guidelines as an advantage of closed methods. Still, in infants, the size of an open incision may not differ much from the combined size of several port-site scars.
05

In which child does the open approach stand out?

The choice of method depends on center experience; guidelines find the success and complication rates of the three approaches comparable.

  • The open approach is often preferred in the following situations: infants under one year old and of low weight; cases where a very small abdominal cavity leaves no room for closed instruments; previous abdominal surgery; some redo cases. Closed methods may stand out in older children and adolescents. The choice is determined by age, weight, anatomy, and team experience through the joint evaluation of two specialists; A side-by-side comparison of the three methods and Which method is chosen for infants? are covered in separate pages.
UPJ Obstruction video guide3 short videos, in order
Frequently asked questions
Is open surgery an 'old-fashioned' method?
No. Open pyeloplasty has the longest-standing follow-up data and a reported success rate of roughly 90–95% or higher — an established method. Closed methods perform the same repair through a different entry route; the open approach is standard at many centers for infants.
Is open surgery safer in infants?
The open approach is a common, safe option in infants; experienced centers report similar results with closed methods as well. The safe method is the one the team has the most experience with. This is why guidelines leave the choice to center experience.
Does the incision grow as the child grows?
The scar lengthens proportionally with the child but becomes relatively smaller and fades. Sun protection and moisturizing in the first months help the scar's appearance. A noticeably raised scar is rare.
Does the hydronephrosis go away completely after surgery?
The hydronephrosis is not expected to disappear completely; the swelling decreases over months, sometimes years. The first check-up ultrasound is usually done at around 3 months. Success is measured by a symptom-free child, decreasing or stable swelling, and preserved function.
←Previous • Pyeloplasty and approachesAnderson–Hynes (Dismembered) PyeloplastyNext • Pyeloplasty and approachesLaparoscopic Pyeloplasty: UPJ Repair Through a Closed (Keyhole) Approach→
Related pagesFull index →
Pyeloplasty and approachesOpen vs. Laparoscopic vs. RoboticIn UPJ obstruction, all three approaches perform the same operation (Anderson–Hynes pyeloplasty) through different routes of access. This page lays open, laparoscopic and robotic pyeloplasty side by side — on success, pain, hospital stay, scarring, age and cost — without taking sides.By age, and special situationsPyeloplasty in Infants and Older ChildrenThe decision for pyeloplasty in an infant is made based on the kidney's course, not age; the approach is chosen based on the baby's size and the center's experience. This page addresses "at how many months" and "open or minimally invasive" separately for infants and older children.Pyeloplasty and approachesAnderson–Hynes (Dismembered) PyeloplastyAnderson–Hynes pyeloplasty is the "dismembered" repair technique in which the narrow UPJ is removed and the ureter is reattached to the renal pelvis. It is the gold standard in both children and adults; this page explains why the technique is preferred and its steps.After surgery and follow-upAfter Pyeloplasty: Care at HomeThe first days after pyeloplasty raise more questions for most families than the operation itself. This page walks through what happens in the hospital, what the drain and catheter are for, pain, feeding and wound care at home, and when you should call us right away.
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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