Endoscopic Management of Ureteric Strictures

Endopyelotomy and endoureterotomy treat obstruction by incising the narrowed segment full-thickness — from normal calibre proximally, through the stricture, into normal calibre distally — and then stenting the cut so the ureter regenerates around it. The incision can be carried out antegrade (percutaneously, prone) or retrograde (ureteroscopically). Minimally invasive pyeloplasty is the gold standard for primary ureteropelvic junction obstruction (UPJO) with the best, most durable outcomes; endoscopic incision is reserved for selected primary UPJO, recurrent or secondary UPJO after failed pyeloplasty, and short benign ureteric or ureteroenteric strictures. The clinical context for upper-tract obstruction is covered in the Urinary Tract Obstruction topic, and the open/robotic alternatives in Ureteral Reconstruction. The unifying principles are a full-thickness incision carried into periureteral fat from healthy tissue to healthy tissue, balloon calibration of the cut, and a period of stented drainage.

Procedure	Target lesion	Route
Antegrade (percutaneous) endopyelotomy	UPJ obstruction, especially with concurrent stones	Antegrade, prone
Retrograde (ureteroscopic) endopyelotomy	UPJ obstruction	Retrograde, lithotomy
Endoureterotomy	Benign ureteric stricture, ideally < 2 cm	Retrograde (semirigid/flexible)
Ureteroenteric endoureterotomy	Ureteroenteric anastomotic stricture	Antegrade ureteroscopic

Indications and Patient Selection

• UPJ obstruction warrants treatment for symptomatic obstruction (ipsilateral flank pain, nausea and vomiting, costovertebral-angle tenderness), associated urolithiasis, recurrent UTIs, or deteriorating renal function. UPJO may be intrinsic (congenital muscular defect, mucosal folds, high ureteral insertion, rarely a ureteral polyp), extrinsic (a crossing accessory/aberrant lower-pole vessel), or acquired (ischaemic fibrosis after surgery, stone impaction, or trauma, or lymphadenopathy).
• Because minimally invasive pyeloplasty is so successful, endoscopic management of UPJO is best reserved for recurrent UPJO after failed pyeloplasty, secondary UPJO, concurrent urolithiasis treated at the same setting, or major comorbidities prohibiting a laparoscopic/robotic approach.
• Benign ureteric strictures are most often iatrogenic (after ureteroscopy), or follow an impacted calculus or an external inflammatory process. Endoureterotomy is first-line for short strictures (< 2 cm); success declines beyond that length, where laparoscopic, robotic, or open reconstruction is preferred.
• Ureteroenteric (anastomotic) strictures usually result from ischaemia after reimplantation of the ureter into a bowel segment, and can be incised antegradely as an alternative to reconstruction.

Contraindications

Absolute

• Active urinary tract infection — defer until sterile urine is documented.
• Uncorrected coagulopathy or bleeding diathesis.

Relative (factors that reduce success)

• A crossing vessel at the UPJ.
• A large redundant renal pelvis or massive hydronephrosis.
• Poor ipsilateral renal function (differential function < 20–25%).
• A narrowed or strictured segment longer than 2 cm.
• Concurrent renal calculi, ischaemic strictures, or extrinsic compression.
• Stent intolerance — the repair depends on weeks of stented drainage.

Preoperative Workup

• Urine culture in every patient, with culture-specific antibiotics for a positive result; sterile urine must be documented before surgery. A parenteral antibiotic is given to reach therapeutic levels before incision.
• Coagulation studies only as indicated by a bleeding history; refer abnormal results for formal haematology review.
• Imaging — a CT angiogram before a UPJ incision to identify a crossing vessel that may preclude safe incision or worsen outcomes. For ureteric strictures, retrograde (and where needed antegrade) studies define stricture location, length, and severity; diuretic renography estimates split function and confirms obstruction.
• Exclude tumour recurrence before incising any stricture in a patient with prior urologic malignancy — particularly a ureteroenteric stricture after surgery for urothelial carcinoma.
• Preoperative stenting is optional. It can relieve pain, improve function, and passively dilate the ureter to ease access, but it may also make the stricture harder to delineate.
• Direction of incision is dictated by the ureteral blood supply — incise away from the vessels:

Stricture level	Safe direction of incision
Proximal ureter / UPJ	Lateral
Middle ureter	Anterior to anteromedial
Distal ureter	Anteromedial
Intramural ureter	Anterior (12 o'clock)

Positioning

• Antegrade (percutaneous) endopyelotomy — prone on a chest-supported table, arms slightly flexed, all pressure points padded; the flank and genitalia widely prepped.
• Retrograde ureteroscopic procedures — modified dorsal lithotomy on a radiolucent table, pressure points padded. General anaesthesia is preferred (spinal is an option).

Antegrade (Percutaneous) Endopyelotomy

A prone, percutaneous incision of the UPJ using rigid instruments — favoured when there are concurrent stones to clear at the same setting.

1. Establish retrograde access. Cystoscopy and retrograde pyelography map the pelvicaliceal anatomy; pass a 0.038-inch Bentson wire up the ureter, place a 5-Fr open-ended ureteral catheter, and secure it to a 16-Fr Foley (the ureteral catheter insertion may be done in lithotomy, then the patient turned prone).
2. Gain percutaneous access through a posterior mid- or upper-pole calyx — the straight route to the UPJ for rigid instruments. Puncture with an 18-gauge Chiba needle during full expiration; gentle air nephrostography (< 5 mL of air) helps mark the posterior calyces in difficult cases.
3. Dilate the tract. Pass a hydrophilic wire, exchange for an extra-stiff wire, dilate with a 30-Fr balloon, and place a 30-Fr Amplatz working sheath.
4. Inspect with a rigid nephroscope. Clear any renal stones first to avoid dislodging fragments into periureteral tissues, then examine the UPJ for pulsations that signal a crossing vessel to avoid.
5. Incise the UPJ. Make a full-thickness incision down to retroperitoneal fat on the posterolateral aspect of the UPJ — the preferred tool is a cold (hook) knife; alternatives are the Ho:YAG laser, endoscopic scissors, or a wire-guided knife. For a very tight UPJ that limits visualisation, an initial 6-mm balloon dilation (4- or 10-cm length) can aid the incision under direct vision. After incising, calibrate the UPJ to 21 Fr with a 7-mm balloon.
6. Document and drain. Antegrade contrast confirms the endopyelotomy. Place a 12/6-Fr endopyelotomy stent with its widest portion across the incised UPJ, and a 16-Fr council-tip Foley (or a 10–12-Fr tube) as a nephrostomy.

Retrograde (Ureteroscopic) Endopyelotomy

A single-stage ureteroscopic incision of the UPJ — no percutaneous tract, but lower success than open/robotic repair (67–86%).

1. Cystoscopy and retrograde pyelogram in modified dorsal lithotomy define the UPJ and the obstructed segment (15–20 mL of dilute contrast opacifies a dilated pelvis).
2. Place wires and access. Pass a 0.035-inch Bentson wire to the renal pelvis as the safety wire; add a stiff working wire through an 8/10-Fr coaxial introducer or dual-lumen catheter; deliver a ureteral access sheath just distal to the UPJ (optional, but it lowers intrarenal pressure and improves vision). Advance a flexible ureteroscope to the UPJ.
3. Define the lesion. Examine the UPJ circumferentially for stricture length and transmitted pulsations from a crossing vessel.
4. Incise. Make a straight lateral full-thickness incision from healthy pelvis, through the narrowed segment, into healthy ureter — extending 1 cm beyond the stricture on each side, cutting layer by layer until periureteral fat is seen.
5. Calibrate. Remove the scope and pass a 4-cm, 15–24-Fr balloon to separate the cut edges. Full inflation at low pressure (2–3 atm), with no waist, confirms an adequate incision.
6. Stent (see Stenting and Drainage).

The incision can be made with any of three direct-vision tools:

Modality	Setup	Notes
Ho:YAG laser	200- or 273-µm fibre, 1.0 J, 10–15 Hz	Default direct-vision tool
Electrocautery	2–3-Fr probe, 30–40 W pure cutting; glycine/sorbitol irrigation during the cut	Insulate the safety wire; switch back to saline once cut; spot-coagulate small bleeders
Cold knife	Uretero-resectoscope with cold knife, short shallow strokes	Advanced into the pelvis alongside the safety wire

Note: the Acucise retrograde cutting balloon has been largely abandoned in favour of the safer direct-vision techniques above.

Endoureterotomy for Ureteric Strictures

Direct-vision incision of a benign ureteric stricture — first-line for a short stricture (< 2 cm).

1. Cystoscopy and retrograde pyelogram confirm the stricture location and length.
2. Choose the scope by level — a semirigid ureteroscope for distal-third strictures below the iliac vessels; a flexible ureteroscope at or above the iliac vessels.
3. Place wires and access. Pass a Bentson safety wire to the pelvis. For strictures at or above the iliac vessels, add a stiff wire (8/10-Fr coaxial introducer or dual-lumen catheter); for more proximal strictures, advance a ureteral access sheath over the stiff wire to 1–2 cm distal to the stricture.
4. Incise with the Ho:YAG laser (200/273-µm fibre, 1.0 J, 10–15 Hz) in the safe direction for the level (see the Preoperative Workup table) — full thickness into periureteral fat, extending 1 cm beyond the stricture on each side, layer by layer.
5. Calibrate the cut with a 4-cm, 15–24-Fr balloon, then stent (see Stenting and Drainage).

Ureteroenteric Strictures

Antegrade ureteroscopic incision of an anastomotic stricture between the ureter and a bowel conduit or pouch.

1. Antegrade access via a mid- or upper-pole calyx gives a straight run down the ureter with minimal scope deflection; an antegrade ureterogram maps the stricture (last-image-hold on the second monitor keeps its full extent in view).
2. Cross the stricture with two wires into the bowel segment — an angled hydrophilic wire with an angiographic catheter, then a second wire via an 8/10-Fr Amplatz introducer or dual-lumen catheter; at least one should be stiff-shafted. Retrieve a wire from the bowel segment with a flexible cystoscope to establish through-and-through access.
3. Position the sheath and scope. Advance a ureteral access sheath antegrade to ≥ 2 cm proximal to the stricture (enough to allow scope deflection), and pass a flexible ureteroscope to the stricture.
4. Exclude malignancy with biopsy performed in advance, then make a full-thickness Ho:YAG incision layer by layer — from 1 cm proximal into the bowel segment, directed toward the conduit/pouch and away from the vessels — until the scope passes freely into the conduit.
5. Calibrate with a balloon and stent (large-calibre end first), and leave a nephrostomy or nephroureteral stent to maintain percutaneous access.

Stenting and Drainage

• Endopyelotomy/endoureterotomy stent — a graduated double-pigtail stent (12/7 or 10/7 Fr) or a standard 7-Fr stent, with the larger-calibre end positioned across the incised segment, left in for 4–6 weeks (6 weeks after antegrade endopyelotomy).
• Foley catheter for low-pressure drainage — eliminating reflux and allowing bleeding to be monitored over the first 12–24 hours.
• Antegrade and ureteroenteric cases keep percutaneous access (nephrostomy or nephroureteral stent), capped after ~24 hours of drainage — especially valuable for ureteroenteric strictures, giving ready drainage if the repair fails.

Outcomes

Success is defined as resolution of symptoms with a radiologically patent UPJ or ureter and stable or improved split renal function.

• Antegrade endopyelotomy — 71–90% (primary) and 74–86% (secondary) success within 1 year. Recurrences occur beyond 1 year, with long-term success falling to ~41% at 10 years, so long-term follow-up is mandatory.
• Retrograde ureteroscopic endopyelotomy — 67–86%, reduced by a crossing vessel, massive hydronephrosis, or poor ipsilateral function.
• Endoureterotomy — best results in short strictures (< 2 cm); favour reconstruction beyond that length.

Complications

• Bleeding — from a crossing vessel or from violating the ureteral blood supply; the reason a crossing vessel is sought preoperatively and the incision is directed away from the vessels. Electrocautery cases allow spot-coagulation of small bleeders.
• Urine extravasation / leak at the incision — managed by the stented, low-pressure drainage that every case relies on; an antegrade nephrostogram documents healing in antegrade cases.
• Failure or recurrent obstruction — more likely with the relative-contraindication factors above, and may present late, hence prolonged surveillance.
• Sepsis — instrumenting infected urine is the rationale for making active UTI an absolute contraindication and documenting sterile urine first. [Note: the sepsis link is inferred — the source chapters mandate sterile urine but do not separately enumerate infective complications.]
• [Note: standard endourologic risks — ureteric injury/perforation and stent-related symptoms — also apply; not detailed in the source chapters.]

Postoperative Care and Follow-Up

• Patients are discharged the same day or the next morning once the urine is no darker than pink or cherry. The Foley is removed at discharge or after 12–24 hours; the ureteral stent is removed cystoscopically at 4–6 weeks.
• A nephroureteral stent or nephrostomy tube can be capped after ~24 hours of drainage; for ureteroenteric strictures it is worth keeping percutaneous access until patency is confirmed.
• First imaging with a diuretic renal scan or excretory urography within 2–4 weeks of stent removal. If the UPJ or ureter is patent, repeat diuretic renography at 3 months, 6 months, and annually for up to 5 years to track ipsilateral function and exclude silent reobstruction.
• After antegrade endopyelotomy specifically, an antegrade nephrostogram is obtained on the first or second postoperative day before the nephrostomy is clamped and removed.

Tips & Pitfalls

• Get a CT angiogram before a UPJ incision. A crossing vessel both predicts failure and is the structure you must not cut.
• Cut from healthy to healthy. Extend the incision 1 cm beyond the stricture on each side and carry it full-thickness to periureteral fat — an incomplete or too-short cut is the commonest reason for failure.
• Let the blood supply set the direction — lateral (proximal/UPJ), anterior-to-anteromedial (mid), anteromedial (distal), anterior (intramural).
• Trust the balloon. Full inflation at 2–3 atm with no waist confirms a complete incision; a persistent waist means cut deeper.
• Keep a safety wire throughout — and insulate it (hydrophilic wire or a catheter sleeve) when using electrocautery.
• Match the procedure to the lesion. Endoscopic incision is for short strictures (< 2 cm) and recurrent/secondary UPJO; primary UPJO and longer strictures do better with pyeloplasty or reconstruction.
• Weigh preoperative stenting both ways — it eases access but can blur the stricture you need to define.
• Exclude tumour first in any patient with prior urologic malignancy, especially a ureteroenteric stricture after urothelial-cancer surgery.
• For ureteroenteric strictures, keep percutaneous access in case the incision fails.