Pyeloplasty

Pyeloplasty reconstructs the ureteropelvic junction (UPJ) to relieve obstruction of urine flow from the renal pelvis into the proximal ureter. The dismembered (Anderson-Hynes) repair is the gold standard, with a > 90% success rate, and laparoscopic/robotic approaches now match the open technique's results with less morbidity — the robotic platform especially, because its wristed instruments ease the delicate anastomotic suturing. UPJ obstruction, its evaluation, and the endourologic alternatives are covered in the Urinary Tract Obstruction topic; this page is the operative reference.

Indications and Evaluation

• Indications for intervention — symptoms (ipsilateral flank pain), stones, infection, deteriorating renal function, and causal hypertension; an asymptomatic patient with indeterminate significance is observed with serial renal scans.
• Etiology (mnemonic SHAVA) — true Stricture, High insertion, Aberrant (crossing) vessel, Kinks/valves, and an Aperistaltic segment. UPJO is intrinsic narrowing in infants and often extrinsic (an accessory lower-pole vessel crossing the UPJ) in older children and adults; contralateral UPJO is the commonest associated anomaly. Intermittent UPJO presents as Dietl's crisis (crampy flank pain, nausea, and vomiting after a fluid load), often from a crossing vessel.
• Evaluation — diuretic nuclear renography (MAG3/Lasix) quantifies split renal function and drainage (T½) and is the key functional test; CT/ultrasound defines anatomy and excludes stones, crossing vessels, and a horseshoe kidney. Remove an indwelling ureteral stent at least ~2 weeks before surgery — it thickens the ureteral/pelvic wall and complicates dissection.

Choosing the Approach

• Endopyelotomy vs pyeloplasty — endopyelotomy (retrograde ureteroscopic or percutaneous antegrade, the lateral wall incised away from crossing vessels) is less invasive but less successful than pyeloplasty (~85–90%); moderate-to-severe hydronephrosis and a crossing vessel predict failure, and it is contraindicated with > 2 cm of obstruction, untreated UTI, or untreated coagulopathy. Pyeloplasty suits almost any anatomy.
• Open vs minimally invasive — laparoscopic/robotic pyeloplasty gives equivalent > 90% success with less pain, shorter stay, and faster recovery (the robotic wrist eases the delicate anastomotic suturing); open repair keeps its edge for complex anatomy, such as an extremely large or malrotated renal pelvis.
• Repair type — the dismembered (Anderson-Hynes) repair is the workhorse: universally applicable, it reduces a redundant pelvis, excises the abnormal UPJ, and is the only method that transposes the UPJ relative to a crossing vessel. Non-dismembered options suit specific anatomy: Foley Y-V plasty (high insertion), Fenger (a short narrowing, closed Heineke-Mikulicz-style), and Culp-DeWeerd/Scardino-Prince flaps (long defects); ureterocalicostomy is for a small intrarenal pelvis or a failed pyeloplasty.

Open Pyeloplasty

Exposure

Most use a flank approach through an anterior incision from the tip of the 12th rib (extraperitoneal, lower than for nephrectomy since only the UPJ needs access); a subcostal or dorsal-lumbotomy incision is an alternative, and bilateral UPJO can be done on both sides in one setting. Place a urethral catheter to prevent bladder distention (which impairs ureteral emptying and risks anastomotic leak), and use loupe magnification. Open Gerota's fascia posteriorly (the peritoneum sweeps posteriorly cranially), preserving the dorsal perinephric fat to cover the repair; a Gil-Vernet retractor at the hilum aids exposure, and a hugely dilated pelvis can be decompressed with a 23- or 25-gauge butterfly needle. Identify the ureter distal to the UPJ, dissect as short a length as possible preserving the adventitial blood supply, and look for an aberrant lower-pole vessel.

Dismembered (Anderson-Hynes)

1. Place a 4-0 stay suture in healthy ureter and transect below the stenotic segment; pass a 5-Fr feeding tube (3.5-Fr umbilical-vein catheter in infants) to confirm distal patency.
2. Mark a diamond-shaped pelvic incision with a long caudal angle, excising the obstructed UPJ and reducing a redundant pelvis (keep away from the caliceal necks).
3. Spatulate the ureter laterally (away from its blood supply; never spiral it) to match the caudal pelvic angle.
4. Place a 6-0 apical suture from the apex of the caudal pelvic angle into the crotch of the spatulated ureter (knot outside the lumen), then run the far wall (locking) and the near wall, catching minimal urothelium and more muscularis/adventitia; close the cranial pelvic defect.

Non-Dismembered and Salvage

• Foley Y-V plasty — for a high insertion without a dysplastic segment; a Y-incision is remodelled into a funnelled V at the dependent pelvis.
• Culp-DeWeerd spiral flap / Scardino-Prince vertical flap — bridge long UPJ/ureteral defects with a dilated pelvis where a dismembered repair would be under tension.
• Davis intubated ureterotomy — for the longest scarred defects (largely replaced by endoscopic incision); incise through the stenosis to healthy ureter, tack loosely over an 8-Fr stent left ~6 weeks, and wrap with fat/omentum.
• Nephropexy — when extensive kidney mobilization is needed for a tension-free repair, fix the lower pole to the quadratus lumborum (2-0 sutures over bolsters, avoiding the nerves).

Drains and Stents

External drainage is essential — a Penrose drain near but not touching the anastomosis (a suction drain prolongs leak). A KISS (kidney internal stent splint) suits infants (removed at 10–21 days); internal double-J stents are preferred in older children and adults. Stenting adds little to a straightforward dismembered repair but is recommended for difficult repairs or a solitary kidney.

Laparoscopic and Robotic Pyeloplasty

Indications are identical to open repair; the transperitoneal route is the default (large working space) versus the steeper-learning-curve retroperitoneal route. Give a second-generation cephalosporin, a bowel prep, and an orogastric tube.

Positioning and Access

After supine induction, a lithotomy retrograde pyelogram excludes a distal obstruction (place a ureteral stent + Foley in women; men are stented antegrade intra-operatively). Reposition to 70° lateral decubitus with the umbilicus at the table break. Establish pneumoperitoneum (10–15 mm Hg) through a 12-mm periumbilical port (Veress or open Hassan).

• Laparoscopic ports — a 30° lens; by the triangulation rule, a 12-mm port cranial and a 5-mm port caudal/lateral ≥ 4 fingerbreadths away, ± a 5-mm assistant port.
• Robotic ports — two 8-mm working trocars placed 10 cm from the camera toward the ASIS (to avoid arm collisions) plus a 12-mm assistant port; dock over the patient's shoulder with a 30°-down camera.

Dismembered Technique

1. Expose — incise the line of Toldt and reflect the colon medially (divide the splenocolic ligament on the left; kocherize the duodenum on the right); open Gerota's at its medial border and identify the ureter (the gonadal vein is a landmark), mobilising it to the pelvis while preserving the adventitia. A hitch stitch through the abdominal wall retracts the pelvis.
2. Transect and spatulate — divide the UPJ superolateral to inferomedial, leaving the obstructed flap on the ureter as a handle; spatulate laterally 1.5–2 cm (do not spiral). Excise a redundant pelvis, avoiding the calices.
3. Anastomose and stent — start the posterior anastomosis at the inferior ureteral apex to the dependent pelvis with running 4-0 monocryl; pass a double-J stent antegrade (over a guidewire, distal position confirmed by flexible cystoscopy), then complete the anterior anastomosis. Drop the pressure to 5 mm Hg to check hemostasis, lay Gerota's/fat over the repair, and place a JP drain.

Variations

• Fenger (non-dismembered) — a short narrowing closed Heineke-Mikulicz-style over a stent.
• Crossing vessel — most crossing vessels do not cause obstruction (consider intrinsic causes too), but a culprit vessel is treated by dismembered pyeloplasty with ventral translocation of the UPJ — not endopyelotomy (hemorrhage risk).
• Transmesocolic — for thin/pediatric patients with a very dilated pelvis (and malrotated/horseshoe kidneys): dissect the UPJ through a mesenteric window without mobilising the colon.
• R-LESS — single-site (GelPoint) pyeloplasty gives better cosmesis with equal success.

Postoperative Care

• Minimally invasive — ambulate, remove the Foley on POD 1 and the JP drain before discharge if output is low (< 60 mL/8 h), discharge ~POD 1, and remove the stent at 4–6 weeks; obtain a MAG3/Lasix renogram at 3 and 6 months, then yearly for ≥ 2 years.
• Open — minimise IV fluids (excess diuresis promotes leak), keep a urethral catheter early, and remove the Penrose when drainage is minimal (usually 1–2 days). Ultrasound at 1 month excludes a urinoma; hydronephrosis often takes > 6 months to improve, so confirm success with diuretic renography at 3–6 months. Failures after 2 years are unusual.

Complications

• Anastomotic/urinary leak is the commonest early complication — manage stepwise (advance the Penrose, then a ureteral stent, then a Foley); a symptomatic urinoma needs percutaneous drainage, but most leaks heal in 1–2 weeks.
• Recurrent UPJ obstruction (~4–5%) — from a missed/mishandled crossing vessel, a non-dependent anastomosis, an unreduced kinking pelvis, or anastomotic stricture; managed by repeat pyeloplasty (a salvage robotic/laparoscopic repair now outperforms endopyelotomy) or ureterocalicostomy.
• Minimally invasive series — intra-operative complications ~2% (accessory-vessel ligation, lost needle, hypercarbia, a cut stent, bowel injury, port hemorrhage) and post-operative complications ~14% (urine leak, hematoma, colon injury, stones).