Ureteroureterostomy

Ureteroureterostomy (UU) is a ureteral reconstruction in which healthy ureter is anastomosed to healthy ureter after excision, bypass, or rerouting of a diseased segment. In its classic form, UU is an ipsilateral end-to-end repair after ureteral transection or short stricture excision. In duplex systems, it is usually an ipsilateral end-to-side anastomosis from the abnormal moiety ureter into the healthy recipient ureter. When the damaged ureter is routed across the midline into the contralateral ureter, the operation becomes transureteroureterostomy.^[1][2][3][5]

This page focuses on ipsilateral ureteroureterostomy. For broader selection logic, see Upper Tract Reconstruction Principles. For distal escalation when the ureter cannot reach without tension, see Ureteral Reimplantation and Boari Flap & Psoas Hitch.

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Configurations

Configuration	Typical Use	Core Idea
Ipsilateral end-to-end UU	Short upper or mid-ureteral transection, traumatic injury, iatrogenic injury, benign stricture	Excise unhealthy ureter and rejoin the two healthy ends over a stent
Ipsilateral end-to-side UU	Duplex collecting system with refluxing or obstructed moiety ureter	Implant the donor ureter into the healthy recipient ureter while preserving the native ureterovesical junction
Transureteroureterostomy	Ipsilateral reconstruction not feasible because of hostile field, inadequate distal ureter, radiation, or bladder limitations	Bring the affected ureter across the midline and anastomose it end-to-side into the contralateral ureter
Pyeloureterostomy	Selected duplex or proximal salvage anatomy	Anastomose pelvis or upper-pole pelvis to ureter when ureter-to-ureter geometry is unfavorable[4]

The shared rule is that the recipient ureter must be healthy, well vascularized, and large enough to accept a wide anastomosis without compromising drainage of either renal unit.

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Indications

Ureteral injury

UU is a first-line repair for complete upper or mid-ureteral transection when the ends can be brought together without tension. The American College of Surgeons best-practice guidance places ureteroureterostomy as the preferred reconstruction for injuries proximal to the iliac vessels; lower-third injuries usually favor ureteroneocystostomy with or without psoas hitch or Boari flap.^[1]

Indications include:

• complete upper or mid-ureteral transection,
• incomplete transection or longitudinal injury suitable for primary repair over a stent,
• postoperative iatrogenic injury when the distal stump is intact,
• selected gynecologic, colorectal, urologic, or emergency-surgery injuries after adequate debridement,
• radiotherapy-associated stenosis only when tissue quality and length remain favorable.^[1][2][6][7]

Benign ureteral stricture

Ipsilateral end-to-end UU is best for a short, well-demarcated stricture of the proximal or mid ureter. It is less attractive when the stricture is long, ischemic, irradiated, multifocal, or distal enough that reimplantation is simpler and safer.^[12][13]

Suitable stricture settings include:

• congenital midureteral stricture or pediatric midureteral obstruction,^[11]
• fibroepithelial polyp with segmental narrowing,
• retrocaval ureter after ureteral rerouting,
• short post-ureteroscopy or post-stone-surgery stricture,
• short benign stricture after failed endoscopic management.

Duplex collecting systems

Ipsilateral end-to-side UU is an established pediatric option for complete duplication when the pathologic moiety ureter drains a functional or salvageable renal segment and the recipient ureter is normal.^[3][4]

Common duplex indications:

• vesicoureteral reflux associated with complete duplication,
• obstructing ectopic ureterocele,
• ectopic obstructed upper-pole ureter,
• massively dilated donor ureter when size mismatch can be handled with tailored spatulation,
• upper-pole preservation when heminephrectomy would sacrifice meaningful function.^{[3][8][9][10]}

Ipsilateral lower-pole reflux is a caution: UU preserves the native ureterovesical junction, so lower-pole reflux may persist unless treated separately.^[9][10]

Renal transplantation

Ureteroureterostomy can replace ureteroneocystostomy in selected pediatric renal transplants, especially when the donor ureter is short, the bladder is augmented or neurogenic, bladder capacity is poor, or prior reimplantation has failed.^[14]

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Patient Selection

The operation succeeds when it repairs a short problem with healthy, mobile ureter. It fails when it is forced to bridge a long gap, devascularized tissue, or a hostile distal field.

Favor UU	Favor Another Reconstruction
Short defect after debridement	Long-segment ureteral loss
Healthy adventitia and preserved blood supply	Radiation fibrosis or ischemic ureter at the planned anastomosis
Upper or mid-ureteral injury	Distal lower-third injury better treated with reimplantation
Tension-free reach after limited mobilization	Need for excessive ureteral mobilization or stretch
Normal recipient ureter in duplex system	Recipient ureter reflux, obstruction, or poor caliber
Stable patient and controlled contamination	Damage-control setting requiring nephrostomy or external drainage

If a tension-free repair is not possible after modest mobilization, escalate rather than forcing the anastomosis. Options include ureteral reimplantation, psoas hitch, Boari flap, buccal mucosa graft onlay, appendiceal onlay/interposition, ileal ureter, transureteroureterostomy, or renal autotransplantation depending on location and length.^[12] In unstable or contaminated emergency settings, source control and urinary diversion take priority over definitive reconstruction.^[17]

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Core Surgical Principles

Successful UU follows the same reconstructive rules emphasized in genitourinary injury guidance and emergency-surgery urinary-tract injury guidelines:^[1][2]

1. Debride to viable ureter. Excise crushed, cauterized, ischemic, or scarred tissue until the ends bleed and hold sutures.
2. Preserve adventitia. Ureteral blood supply is longitudinal and periureteral; avoid skeletonizing the ureter.
3. Mobilize only enough. Over-mobilization can create the very ischemia the operation is trying to solve.
4. Spatulate both ends. Opposite-side spatulation creates a wide, noncircumferential narrowing-prone anastomosis.
5. Sew mucosa to mucosa. Use fine absorbable sutures, commonly 4-0 or 5-0 depending on size and approach.
6. Stent the repair. Place a double-J stent across the anastomosis.
7. Make it watertight and tension-free. A perfect-looking anastomosis under stretch is a future stricture.
8. Drain and cover. Place a drain when leak risk matters and cover with peritoneum or omentum when available.

For a partial longitudinal injury, the laceration can be repaired transversely over a stent in a Heineke-Mikulicz fashion to avoid narrowing.^[1]

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Ipsilateral End-to-End Technique

Exposure

• Expose the injured or strictured ureter through open, laparoscopic, or robotic access.
• Identify healthy ureter above and below the lesion before transection.
• Preserve periureteral adventitia and avoid circumferential stripping beyond what is necessary.
• Obtain proximal and distal control in trauma or leak settings.

Excision and preparation

1. Excise the diseased segment completely.
2. Confirm brisk bleeding and healthy mucosa at each end.
3. Mobilize the ureter only enough for a tension-free apposition.
4. Spatulate the proximal and distal ends on opposite sides.
5. Check orientation carefully; rotation is easy in minimally invasive repairs.

Anastomosis

1. Place stay sutures at the spatulation apices.
2. Sew the posterior wall with interrupted or running absorbable suture.
3. Insert a double-J stent across the repair.
4. Complete the anterior wall without narrowing the lumen.
5. Test visually for tension, kinking, and twisting.
6. Place a drain when there was urinoma, contamination, reoperative dissection, or tenuous tissue.

Length rule

The limiting factor is not the measured gap alone; it is the gap after full debridement to healthy ureter. A 2 cm injury can become a 4 cm reconstruction once cautery damage and scar are removed.

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Ipsilateral End-to-Side Technique for Duplex Systems

End-to-side UU in duplex systems transfers drainage from a diseased donor ureter into a healthy recipient ureter while preserving the recipient ureterovesical junction. It avoids bladder dissection, avoids creating a new antireflux tunnel, and can preserve upper-pole function.^[3][4][9]

Core steps:

1. Identify donor and recipient ureters; confirm recipient ureter health and orientation.
2. Mobilize the donor ureter distally enough to prevent tension, but leave a short, safe distal stump when complete excision would risk pelvic injury.
3. Transect and spatulate the donor ureter.
4. Create a longitudinal ureterotomy on the recipient ureter.
5. Sew a wide end-to-side mucosa-to-mucosa anastomosis.
6. Stent one or both ureters depending on size, surgeon preference, and reconstruction geometry.
7. Confirm no kinking of the recipient ureter and no obstruction to the lower-pole moiety.

Large donor-to-recipient size mismatch is not by itself a contraindication. In the classic 100-UU pediatric series, significant ureteral size disparity greater than 2:1 was common and did not preclude success.^[3]

Distal stump management

A retained distal ureteral stump is usually left to avoid unnecessary pelvic morbidity, but it can become symptomatic. Lee et al. found stump UTI in 12.2% after proximal ureteroureterostomy, with larger preoperative upper-pole ureter diameter as the main risk factor and reoperation occurring at a median 2.4 years.^[18]

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Surgical Approaches

Approach	Best Fit	Evidence Signal
Open	Trauma, unstable patient, emergency exploration, complex reoperative field	Most established; preferred when exposure, speed, and vascular control matter[1][2]
Laparoscopic	Benign strictures and selected midureteral obstruction	Simmons et al. reported 100% patency in 12 laparoscopic reconstructions versus 96% in 34 open repairs, with less blood loss and shorter hospitalization[13]
Robot-assisted	Benign strictures, duplex anomalies, distal non-neoplastic lesions in experienced hands	Wristed suturing supports precise intracorporeal UU; 2025 systematic review of minimally invasive UU for non-neoplastic distal lesions reported success from 81.8-100%[7][12]
Endoscopic recanalization and UU	Highly selected obliterated segments	Tsai et al. described successful recanalization in 9 of 10 attempts, but 30% required later dilation[16]

The approach should not change the operation's standards. If the ureter is ischemic, under tension, or too long a defect for direct repair, minimally invasive access should not be used to justify an undersized reconstruction.

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Outcomes by Indication

Injury and benign stricture

Minimally invasive UU for non-neoplastic distal ureteral lesions has emerged as a robotic-era alternative to routine reimplantation in carefully selected cases. In a 2025 systematic review of 7 studies and 116 patients, success ranged from 81.8% to 100%.^[7] For benign stricture disease more broadly, laparoscopic ureteral reconstruction achieved 100% patency in 12 patients at a mean 23-month follow-up compared with 96% in 34 open patients.^[13]

Postoperatively detected lower ureteral injuries are usually managed with reimplantation, but UU can work when the distal stump is intact. Paick et al. reported 100% success in 9 patients with a mean 33.7-month follow-up.^[6]

Duplex systems

The largest classic pediatric experience included 100 ureteroureterostomies in 94 children, with 94% overall success: 96% for reflux, 91% for ureterocele, and 94% for ectopic obstructed upper-pole ureter.^[3] Later series reinforced that severe dilation or size mismatch should not automatically exclude UU when the recipient ureter is healthy.^[9]

Mid-term data now support durability. In a 2025 pediatric duplex-anomaly cohort with median 60-month follow-up, 98% of operated moieties had resolved, improved, or stable dilation after open or robot-assisted UU; de novo recipient-moiety hydronephrosis occurred in 7%, and all cases were asymptomatic.^[15] Yo-yo reflux between the connected ureters is rarely diagnosed and is usually clinically irrelevant.^[15]

Renal transplantation

In selected pediatric renal transplants, UU can avoid a difficult bladder. Penna et al. reported use in 23 of 213 transplants (10.8%), with 2 urinary leaks (8%) and no allograft losses.^[14]

Transureteroureterostomy

TUU is a different operation and should be reserved for scenarios where ipsilateral repair is not feasible. In the long-term series by Iwaszko et al., patency was 96.4% among patients with imaging follow-up at a mean 5.8 years; GFR improved from 62.8 to 71.8 mL/min postoperatively, and stone disease developed in 12.7%.^[5]

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Complications

Complication	Notes
Urinary leak or prolonged drain output	Most common issue in the pediatric duplex series; usually does not equal reconstruction failure[3]
Anastomotic stricture	Main long-term concern after any UU; higher secondary dilation signal in endoscopic series[16]
Recipient ureter obstruction	Duplex end-to-side UU can theoretically narrow or kink the recipient ureter; mid-term de novo hydronephrosis was uncommon and asymptomatic in the 2025 cohort[15]
Distal ureteral stump UTI	12.2% after proximal UU in one stump-complication study; larger preoperative upper-pole ureter diameter increased risk[18]
De novo VUR	Reported after UU alone in duplex systems; lower-pole reflux should be assessed before choosing UU as a standalone operation[9]
Urinoma	More likely when drainage is inadequate or a stent is omitted[9]
Stone formation	Particularly relevant after TUU; long-term TUU series reported 12.7% stone disease[5]

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Comparison With Alternatives

Feature	Ureteroureterostomy	Ureteroneocystostomy	Transureteroureterostomy
Best location	Upper or mid ureter; selected distal lesions	Distal ureter	Ipsilateral field unusable
Bladder surgery	Avoided	Required	Avoided
Native antireflux mechanism	Preserved	Recreated or modified	Preserved on donor side, but contralateral ureter is now shared drainage
Key requirement	Healthy ureter and tension-free reach	Adequate bladder capacity and mobility	Healthy contralateral ureter and safe midline crossing
Main limitation	Gap length and ureteral vascularity	Bladder limitations, cystotomy, possible hitch/flap need	Puts both renal units at some risk if recipient ureter obstructs
Typical use	Trauma, iatrogenic injury, short benign stricture, duplex anomaly	Distal injury or stricture	Salvage when ipsilateral repair or bladder-based repair is poor

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Advantages

• Preserves bladder integrity and avoids cystotomy in selected cases.
• Maintains the native ureterovesical junction and antireflux mechanism.
• Can be faster and less morbid than reimplantation when the distal stump is intact.
• Works across pediatric duplex, adult stricture, injury, and transplant settings.
• Handles even marked ureteral size disparity when spatulation and recipient selection are correct.^{[3][6][7][14]}
• Has long-standing pediatric use for reflux associated with ureteral duplication, with preservation of the native ureterovesical junction when recipient anatomy is favorable.^[19]

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Limitations and Relative Contraindications

• lower-third ureteral injuries where reimplantation is more reliable,
• long ureteral loss after full debridement,
• ischemic, radiated, crushed, or devascularized ureteral ends,
• unstable trauma or septic patient needing drainage first,
• active uncontrolled infection or urinoma without source control,
• recipient ureter reflux or obstruction in duplex anatomy,
• need for excessive mobilization to make the ends meet.

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Operative Pearls

• Decide after debridement, not before it; the true defect is what remains after bad ureter is gone.
• Keep periureteral tissue attached whenever possible.
• Spatulate generously and on opposite sides.
• A drain is cheap insurance when the case began with leak, urinoma, infection, or reoperative scarring.
• In duplex systems, size mismatch is less important than recipient ureter health and avoiding recipient kinking.
• In distal injuries, do not force UU just to avoid the bladder; a clean ureteroneocystostomy is often the better operation.
• If ipsilateral tissues are hostile but the contralateral ureter is healthy, consider TUU deliberately rather than as an intraoperative improvisation.

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References

1. Johnsen N, Wessells H, Archer-Arroyo K, et al. Best Practices Guidelines: Management of Genitourinary Injuries. American College of Surgeons; 2025.

2. de'Angelis N, Schena CA, Marchegiani F, et al. 2023 WSES guidelines for the prevention, detection, and management of iatrogenic urinary tract injuries during emergency digestive surgery. World J Emerg Surg. 2023;18(1):45. doi:10.1186/s13017-023-00513-8.

3. Lashley DB, McAleer IM, Kaplan GW. Ipsilateral ureteroureterostomy for the treatment of vesicoureteral reflux or obstruction associated with complete ureteral duplication. J Urol. 2001;165(2):552-554. doi:10.1097/00005392-200102000-00067.

4. Huisman TK, Kaplan GW, Brock WA, Packer MG. Ipsilateral ureteroureterostomy and pyeloureterostomy: a review of 15 years of experience with 25 patients. J Urol. 1987;138(5):1207-1210. doi:10.1016/s0022-5347(17)43551-8.

5. Iwaszko MR, Krambeck AE, Chow GK, Gettman MT. Transureteroureterostomy revisited: long-term surgical outcomes. J Urol. 2010;183(3):1055-1059. doi:10.1016/j.juro.2009.11.031.

6. Paick JS, Hong SK, Park MS, Kim SW. Management of postoperatively detected iatrogenic lower ureteral injury: should ureteroureterostomy really be abandoned? Urology. 2006;67(2):237-241. doi:10.1016/j.urology.2005.08.041.

7. Rosato E, Miano R, Pastore A, et al. Ureteroureterostomy for the management of non-neoplastic distal ureteral lesions: a new challenger of care in the era of robotic surgery? J Endourol. 2025;39(2):157-165. doi:10.1089/end.2024.0735.

8. Ahmed S, Boucaut HA. Vesicoureteral reflux in complete ureteral duplication: surgical options. J Urol. 1988;140(5 Pt 2):1092-1094. doi:10.1016/s0022-5347(17)41968-9.

9. Chacko JK, Koyle MA, Mingin GC, Furness PD. Ipsilateral ureteroureterostomy in the surgical management of the severely dilated ureter in ureteral duplication. J Urol. 2007;178(4 Pt 2):1689-1692. doi:10.1016/j.juro.2007.05.098.

10. Prieto J, Ziada A, Baker L, Snodgrass W. Ureteroureterostomy via inguinal incision for ectopic ureters and ureteroceles without ipsilateral lower pole reflux. J Urol. 2009;181(4):1844-1848. doi:10.1016/j.juro.2008.12.004.

11. Lu L, Bi Y, Wang X, Ruan S. Laparoscopic resection and end-to-end ureteroureterostomy for midureteral obstruction in children. J Laparoendosc Adv Surg Tech A. 2017;27(2):197-202. doi:10.1089/lap.2016.0222.

12. Drain A, Jun MS, Zhao LC. Robotic ureteral reconstruction. Urol Clin North Am. 2021;48(1):91-101. doi:10.1016/j.ucl.2020.09.001.

13. Simmons MN, Gill IS, Fergany AF, Kaouk JH, Desai MM. Laparoscopic ureteral reconstruction for benign stricture disease. Urology. 2007;69(2):280-284. doi:10.1016/j.urology.2006.09.067.

14. Penna FJ, Lorenzo AJ, Farhat WA, Butt H, Koyle MA. Ureteroureterostomy: an alternative to ureteroneocystostomy in select cases of pediatric renal transplantation. J Urol. 2017;197(3 Pt 2):920-924. doi:10.1016/j.juro.2016.09.120.

15. Eftekharzadeh S, Aghababian A, Abdulfattah S, et al. Ureteroureterostomy as definitive intervention for duplex anomalies: a mid-term analysis. Urology. 2025;204:159-163. doi:10.1016/j.urology.2025.05.028.

16. Tsai CK, Taylor FC, Beaghler MA. Endoscopic ureteroureterostomy: long-term followup using a new technique. J Urol. 2000;164(2):332-335.

17. Aaron EA, Amabile A, Andolfi C, et al. Gastrointestinal Surgical Emergencies Textbook. American College of Surgeons; 2021.

18. Lee YS, Hah YS, Kim MJ, et al. Factors associated with complications of the ureteral stump after proximal ureteroureterostomy. J Urol. 2012;188(5):1890-1894. doi:10.1016/j.juro.2012.07.015.

19. Jelloul L, Valayer J. Ureteroureteral anastomosis in the treatment of reflux associated with ureteral duplication. J Urol. 1997;157(5):1863-1865.