Ileal Ureter
Ileal ureter replacement interposes a vascularized ileal segment between the proximal ureter or renal pelvis and the bladder to reconstruct long-segment ureteral loss. It is a salvage operation for defects that cannot be solved by ureteroureterostomy, ureteral reimplantation, Boari flap / psoas hitch, or oral-mucosa onlay reconstruction.[1][2][3]
The operation works because ileum is mobile, vascular, and tubular. It is costly because bowel mucosa in the urinary tract produces mucus, absorbs ammonium chloride, secretes bicarbonate, and can create metabolic acidosis, stones, infection, and long-term nutritional issues. Ileal ureter is therefore best thought of as the standard native-tissue exit ramp before renal autotransplantation or diversion, not an early reconstructive move.[1][4][5]
For the location-based ladder, see Principles of Upper Tract Reconstruction. For the disease workup, see Ureteral Stricture. For bowel physiology, see Bowel Anatomy, Mucus Management, Vitamin B12 Supplementation, and Urinary Acidifiers & Alkalinizers.
Indications
Ileal ureter is reserved for complex ureteral defects where a durable native repair would be under tension, ischemic, too narrow, or impossible.[1][2][6]
Common indications:
- long-segment or panureteral benign stricture,
- radiation-induced ureteral stricture,
- extensive iatrogenic ureteral injury,
- retroperitoneal fibrosis,
- ureteral loss after oncologic resection,
- failed prior pyeloplasty, reimplantation, Boari flap, or endoscopic management,
- bilateral extensive ureteral strictures,
- solitary kidney with a long ureteral stricture when salvage is worth the bowel burden,
- endemic infectious strictures such as tuberculosis or schistosomiasis where relevant.[1][2][3][7]
The threshold question
Before choosing ileal ureter, ask:
- Can the kidney be drained with a simpler native repair?
- Is renal function adequate enough to tolerate bowel in the urinary tract?
- Is usable, non-radiated ileum available?
- Is the bladder a safe low-pressure recipient?
- Would renal autotransplantation or diversion be better for this patient?
Contraindications and Caution Zones
| Problem | Why It Matters |
|---|---|
| Advanced renal insufficiency | Acidosis risk rises when renal acid excretion reserve is poor |
| Short bowel syndrome or major prior ileal resection | Nutritional and diarrheal morbidity may be unacceptable |
| Active inflammatory bowel disease involving ileum | Diseased bowel should not be used as urinary conduit |
| Radiation enteritis or irradiated ileum | High stricture, fistula, and leak risk |
| Uncontrolled UTI or urosepsis | Drain first; reconstruct electively after infection control |
| Small-capacity or high-pressure bladder | Distal implantation into hostile storage threatens the kidney |
| Severe hepatic dysfunction | Ammonium reabsorption can rarely contribute to encephalopathy |
| Poor surgical fitness for bowel anastomosis | Ileal ureter is a major abdominal reconstruction |
Many series use renal insufficiency as a relative rather than absolute contraindication. The safer framing is practical: the lower the eGFR and serum bicarbonate reserve, the more strongly the team should favor shorter bowel length, Yang-Monti configuration, renal autotransplantation, diversion, or nephrectomy if renal salvage is not worthwhile.[4][8]
Preoperative Planning
Preoperative planning should define the defect, the kidney, the bladder, and the bowel.
| Domain | Evaluation | Purpose |
|---|---|---|
| Renal function | Serum creatinine, eGFR, electrolytes, bicarbonate, MAG3 split function | Determines salvage value and metabolic reserve |
| Anatomy | CT urogram, MR urogram, antegrade/retrograde pyelography | Defines stricture length, laterality, renal pelvis target, and bladder reach |
| Drainage status | Nephrostomy, stent history, urine culture | Controls infection and lets inflammation settle before reconstruction |
| Bladder | Cystoscopy, capacity assessment, urodynamics selectively | Confirms safe distal reservoir |
| Bowel | Prior resections, radiation fields, IBD history, nutritional risk | Confirms usable non-radiated ileum |
| Metabolic baseline | Bicarbonate, chloride, potassium, B12 when relevant | Creates postoperative comparison |
Preoperative CT can help estimate required ileal segment length, but final segment choice is made intraoperatively after the ureter is debrided to healthy tissue and the bladder/kidney are mobilized.[9]
Standard Ileal Ureter Technique
The standard operation uses a non-reconfigured ileal segment, usually 15-25 cm for unilateral reconstruction and longer for bilateral or panureteral defects.[1][2][5]
Step sequence
- Expose and stage the ureter. Identify the diseased segment, preserve any usable periureteral blood supply, and debride to healthy ureter or renal pelvis.
- Prepare the proximal target. Spatulate the proximal ureter or open the renal pelvis for a wide ileoureteral or ileopyelostomy anastomosis.
- Select ileum. Choose a mobile, well-vascularized ileal segment while preserving the terminal ileum when possible to protect bile-salt and B12 absorption.
- Harvest on mesentery. Isolate the segment on an intact mesenteric pedicle and confirm reach without twisting.
- Restore bowel continuity. Perform stapled or hand-sewn ileoileostomy and close the mesenteric defect.
- Orient isoperistaltically. Place the oral end proximally and the aboral end distally so intestinal peristalsis supports antegrade urine transport.
- Perform proximal anastomosis. Sew ileum to renal pelvis or proximal ureter with absorbable suture over a stent.
- Perform distal anastomosis. Implant the distal ileum into the bladder, usually refluxing unless antireflux reconstruction is specifically indicated.
- Stent and drain. Stent the reconstruction, leave Foley drainage, and place a closed suction drain.
- Retroperitonealize when possible. Route the ileal ureter along the natural ureteral course while avoiding mesenteric tension, kinking, and internal hernia.
Key technical rules
- Use the shortest segment that reaches without tension. Bowel length is metabolic surface area.
- Preserve terminal ileum when possible. This protects B12 and bile-salt absorption.
- Avoid mesenteric twist. A perfect anastomosis fails if the ileal segment is ischemic or kinked.
- Spatulate generously. Anastomotic stricture usually starts with ischemia, tension, or caliber mismatch.
- Control dead space. Urine leak near bowel and retroperitoneum can become abscess or fistula.
Yang-Monti Ileal Ureter
The Yang-Monti modification uses a short ileal segment that is divided, detubularized, and retubularized transversely into a longer narrow tube. It reduces bowel length and mucosal surface area while producing a caliber closer to ureter.[8][10]
Concept
- Isolate 5-7.5 cm of ileum.
- Divide into two or three short segments.
- Incise each segment along the antimesenteric or paramesenteric border.
- Retubularize the opened plates into a longer narrow tube over a catheter.
- Interpose the reconstructed tube as a neo-ureter.
Advantages
- far less bowel used than standard ileal ureter,
- less mucus surface area,
- lower expected metabolic burden,
- suitable caliber for submucosal tunneling,
- useful in solitary kidney or mild-moderate CKD when defect length permits.[8][10]
In the long-term Yang-Monti series, renal function parameters improved overall and metabolic complications were not observed, but patients with more advanced CKD still deteriorated, reinforcing that renal reserve remains the limiting variable.[8]
Other Modifications
Tapered ileal ureter
Tapering reduces the diameter of a standard ileal segment to reduce urinary stasis and make antireflux implantation easier. The trade-off is more bowel manipulation, staple/suture line length, and potential ischemia.
Ileal onlay flap
When a ureteral plate remains usable, detubularized ileum can be used as an onlay rather than circumferential replacement. This preserves native ureteral blood supply and reduces the amount of bowel mucosa exposed to urine. In a reconfigured intestinal-segment series, renal function was preserved in most evaluable renal units with only minor mucus symptoms.[11]
Combined Boari / ileal ureter
For full-length defects, a Boari flap with psoas hitch can bridge the distal gap while a shorter ileal segment bridges the proximal gap. This reduces the total ileal length needed and can preserve bladder-based distal reconstruction.[12]
Downward nephropexy
Downward nephropexy mobilizes the kidney caudally to reduce the remaining gap. It is useful when an ileal or Boari-based reconstruction almost reaches but would otherwise be under tension.[13][14]
Antireflux Strategy
Whether the distal ileovesical anastomosis needs an antireflux mechanism is debated.[5][15][16]
Refluxing anastomosis
Arguments for refluxing implantation:
- technically simpler,
- lower distal obstruction risk,
- acceptable when implanting into a normal low-pressure native bladder,
- long ileal segments may damp visible reflux through bowel peristalsis and capacitance.[5][16]
The largest single-center series concluded that reflux prevention is of minor importance when the native bladder is the recipient, but more important when implanting into an intestinal reservoir.[5]
Antireflux anastomosis
Arguments for antireflux implantation:
- recurrent pyelonephritis concern,
- high-pressure reservoir or bowel reservoir recipient,
- solitary kidney or vulnerable renal unit,
- pediatric or young patient with long expected exposure.
Techniques include submucosal tunnel, nipple valve, ileo-psoas tunnel, and serous-lined extramural tunnel into an intestinal reservoir.[15][17] The price of antireflux design is obstruction risk; avoid a clever valve that turns into a stricture.
Outcomes
| Study | N | Follow-up | Key Findings |
|---|---|---|---|
| Chung 2006 | 56 | Mean 6 yr | Long-term safety of bowel ureteral replacement; stable median creatinine[18] |
| Armatys 2009 | 91 | Mean 36 mo | Most patients had stable/decreased creatinine; anastomotic stricture and fistula were uncommon but real[19] |
| Kocot 2017 | 157 | Mean 54.1 mo | 25-year single-center experience; creatinine stable or improved in most patients[5] |
| Roth 2017 | 108 | Median 51 mo | 82.4% stable/improved renal function; bilateral repair increased renal-deterioration risk[6] |
| Launer 2021 | 46 | Mean 4.4 yr | 83% no reintervention; 24% major complication rate[2] |
| Ali-El-Dein 2021 | 36 | Median 68 mo | Yang-Monti: improved eGFR overall, no metabolic complications reported[8] |
| Yang 2023 | 15 | Median 14 mo | Totally intracorporeal robotic unilateral/bilateral ileal ureter feasible; functional success 86.7%[20] |
| Ji 2026 | 48 | Median 24 mo | Multi-institutional robotic RIUR: 91.7% success; radiation subgroup lower success[21] |
Across series, durable success is usually high enough to justify the operation in salvage settings, but complication rates are not trivial. This is not a low-morbidity substitute for Boari flap or buccal graft ureteroplasty; it is what remains when those options cannot succeed.
Robotic Ileal Ureter Replacement
Robotic intracorporeal ileal ureter replacement has moved from case report to multi-institutional practice, especially at high-volume reconstructive centers.[20][21][22]
Totally intracorporeal sequence
- Position to access kidney/ureter, bowel, and bladder; port strategy depends on unilateral vs bilateral reconstruction.
- Identify diseased ureter and debride to healthy proximal target.
- Measure the defect after mobilization and adjunctive bladder/kidney maneuvers.
- Harvest ileum intracorporeally.
- Restore bowel continuity with intracorporeal stapled or hand-sewn anastomosis.
- Orient the ileal segment isoperistaltically.
- Complete proximal ileopyelostomy or ileoureterostomy.
- Complete distal ileovesicostomy.
- Place stents, Foley, and drains.
Extracorporeal segment preparation
Some robotic cases use a small extraction incision for ileal harvest and preparation, then return the segment for robotic urinary anastomoses. This can reduce intracorporeal bowel time while preserving minimally invasive urinary reconstruction.[23]
Bilateral configurations
Bilateral reconstructions may use:
- one long U-shaped ileal segment,
- reverse-7 or asymmetric configuration,
- separate ileal segments,
- ileal segment plus Boari/psoas adjuncts depending on bladder and defect geometry.[7][20][23]
In the 2026 multi-institutional robotic series, 48 patients underwent robotic intracorporeal ileal ureter replacement across three institutions; 35.4% were bilateral and 41.7% had prior radiation. Major complications occurred in 18.8%, and success was 91.7% at median 24-month follow-up. Radiation history was the major warning signal: success was lower in irradiated patients.[21]
Complications
| Complication | Mechanism | Prevention / Management |
|---|---|---|
| Hyperchloremic metabolic acidosis | Ileum absorbs ammonium chloride and secretes bicarbonate | Use shortest bowel length, monitor bicarbonate/chloride, oral alkali |
| Mucus obstruction | Ileal mucosa continues mucus secretion | Hydration, irrigation when needed, endoscopic clearance rarely |
| Anastomotic stricture | Ischemia, tension, caliber mismatch, radiation | Wide spatulation, healthy margins, tension-free routing |
| Urinary leak / fistula | Anastomotic leak, distal obstruction, infected field | Stents, Foley drainage, drains, delayed reconstruction after sepsis |
| UTI / pyelonephritis | Reflux, stasis, mucus, colonization | Treat symptomatic infection; evaluate obstruction or reflux if recurrent |
| Small bowel obstruction | Adhesions or internal hernia | Close mesenteric defects; manage conservatively or surgically |
| Worsening renal function | Baseline CKD, bilateral repair, infection, obstruction, acidosis | Careful selection, lifelong monitoring, early obstruction workup |
| Stones | Mucus, infection, urinary stasis | Surveillance imaging, treat infection/stasis |
| B12 deficiency / bile-salt diarrhea | Terminal ileal loss | Preserve terminal ileum; monitor and supplement |
Metabolic acidosis is the signature long-term problem. Chronic acidosis can worsen bone health and potassium balance, and patients with reduced renal function have less reserve to compensate.[4]
Alternatives
| Option | Best Fit | Why It May Beat Ileal Ureter |
|---|---|---|
| Psoas hitch | Lower/mid ureteral defect | No bowel in urine; lower metabolic burden |
| Boari flap | Mid/upper defect with good bladder | Uses bladder tissue instead of bowel |
| Buccal mucosa graft ureteroplasty | Long nonobliterative stricture with ureteral plate | Avoids bowel anastomosis and metabolic complications |
| Appendiceal interposition/onlay | Right-sided moderate defect, normal appendix | No bowel anastomosis; small caliber |
| Transureteroureterostomy | Bladder unavailable, contralateral ureter healthy | Avoids bowel but risks contralateral renal unit |
| Renal autotransplantation | Long proximal/panureteral disease with bowel contraindication | Avoids bowel mucosa; adds transplant-level vascular risk |
| Diversion or nephrectomy | Poor bladder, poor renal function, unsafe reconstruction | May be safer than heroic salvage |
Recent robotic comparisons increasingly frame ileal ureter and renal autotransplantation as competing salvage tools for long strictures; choice depends on bowel suitability, vascular anatomy, renal function, prior radiation, and center expertise.[24]
Surveillance
Ileal ureter patients need lifelong follow-up.
| Surveillance | Typical Interval | Why |
|---|---|---|
| Serum creatinine / eGFR | Every 6-12 mo | Detect obstruction, infection-related injury, CKD progression |
| Electrolytes, bicarbonate, chloride, potassium | Every 6-12 mo | Detect hyperchloremic metabolic acidosis |
| Renal ultrasound or CT/MR urography | At least annually early; individualized long term | Detect hydronephrosis, stones, mucus obstruction |
| MAG3 renography | Symptoms, worsening imaging, solitary kidney, uncertain drainage | Functional obstruction assessment |
| Vitamin B12 | Annually if terminal ileum or longer ileal length used | Detect delayed deficiency |
| Bone health | Consider with chronic acidosis | Acidosis can worsen bone buffering and mineral loss |
| Urine culture | Symptomatic only | Asymptomatic bacteriuria is common and usually not treated |
Operative Pearls
- Use ileal ureter late, not lazily. First exhaust tension-free native, bladder-based, and onlay options.
- Do not use radiated bowel. Radiation strictures often need bowel, but not bowel from the radiation field.
- Keep the segment short. Every extra centimeter is more mucus and metabolic surface area.
- Preserve terminal ileum. B12 and bile-salt absorption matter years later.
- Orient isoperistaltically. Make the bowel help drainage rather than fight it.
- Bilateral repairs are different biology. Expect higher renal-function risk and monitor more aggressively.
- Radiation predicts trouble. Counsel that success is lower and complications higher after pelvic radiation.
- Antireflux is context-dependent. Native low-pressure bladder often tolerates refluxing implantation; reservoirs deserve stronger reflux prevention.
- Lifelong metabolic surveillance is part of the operation. The reconstruction is not finished when the stent comes out.
References
1. Xiong S, Zhu W, Li X, et al. Intestinal interposition for complex ureteral reconstruction: a comprehensive review. Int J Urol. 2020;27(5):377-386. doi:10.1111/iju.14222
2. Launer BM, Redger KD, Koslov DS, et al. Long-term follow up of ileal ureteral replacement for complex ureteral strictures: single institution study. Urology. 2021;157:257-262. doi:10.1016/j.urology.2021.07.012
3. Chung BI, Hamawy KJ, Zinman LN, Libertino JA. The use of bowel for ureteral replacement for complex ureteral reconstruction: long-term results. J Urol. 2006;175(1):179-183. doi:10.1016/S0022-5347(05)00061-3
4. Roth JD, Koch MO. Metabolic and nutritional consequences of urinary diversion using intestinal segments to reconstruct the urinary tract. Urol Clin North Am. 2018;45(1):19-24. doi:10.1016/j.ucl.2017.09.007
5. Kocot A, Kalogirou C, Vergho D, Riedmiller H. Long-term results of ileal ureteric replacement: a 25-year single-centre experience. BJU Int. 2017;120(2):273-279. doi:10.1111/bju.13825
6. Roth JD, Monn MF, Szymanski KM, Bihrle R, Mellon MJ. Ureteral reconstruction with ileum: long-term follow-up of renal function. Urology. 2017;104:225-229. doi:10.1016/j.urology.2017.02.026
7. Kim A, Nam W, Song SH, Jeong IG, Hong B. Use of the ileum for ureteral stricture and obstruction in bilateral, unilateral, and single-kidney cases. Urology. 2018;111:203-207. doi:10.1016/j.urology.2017.08.008
8. Ali-El-Dein B, El-Hefnawy AS, D'Elia G, et al. Long-term outcome of Yang-Monti ileal replacement of the ureter: a technique suitable for mild, moderate loss of kidney function and solitary kidney. Urology. 2021;152:153-159. doi:10.1016/j.urology.2020.09.061
9. Baumgarten AS, Shah BB, Patel TB, Wiegand LR. Robotic ileal interposition for radiation-induced ureteral stricture disease. Urology. 2017;104:9-10. doi:10.1016/j.urology.2017.02.033
10. Ali-el-Dein B, Ghoneim MA. Bridging long ureteral defects using the Yang-Monti principle. J Urol. 2003;169(3):1074-1077. doi:10.1097/01.ju.0000050151.66653.cc
11. Ordorica R, Wiegand LR, Webster JC, Lockhart JL. Ureteral replacement and onlay repair with reconfigured intestinal segments. J Urol. 2014;191(5):1301-1306. doi:10.1016/j.juro.2013.11.027
12. Zhong W, Du Y, Yang K, et al. Ileal ureter replacement combined with Boari flap-psoas hitch to treat full-length ureteral defects: technique and initial experience. Urology. 2017;108:201-206. doi:10.1016/j.urology.2017.07.014
13. Mauck RJ, Hudak SJ, Terlecki RP, Morey AF. Central role of Boari bladder flap and downward nephropexy in upper ureteral reconstruction. Int Braz J Urol. 2011;37(5):648-654.
14. Hofer MD, Aguilar-Cruz HJ, Singla N, et al. Expanding applications of renal mobilization and downward nephropexy in ureteral reconstruction. Urology. 2016;94:232-236. doi:10.1016/j.urology.2016.04.008
15. Bonfig R, Gerharz EW, Riedmiller H. Ileal ureteric replacement in complex reconstruction of the urinary tract. BJU Int. 2004;93(4):575-580. doi:10.1111/j.1464-410X.2003.04672.x
16. Waldner M, Hertle L, Roth S. Ileal ureteral substitution in reconstructive urological surgery: is an antireflux procedure necessary? J Urol. 1999;162(2):323-326.
17. Xu YM, Feng C, Kato H, Xie H, Zhang XR. Long-term outcome of ileal ureteric replacement with an iliopsoas muscle tunnel antirefluxing technique for the treatment of long-segment ureteric strictures. Urology. 2016;88:201-206. doi:10.1016/j.urology.2015.11.005
18. Armatys SA, Mellon MJ, Beck SD, et al. Use of ileum as ureteral replacement in urological reconstruction. J Urol. 2009;181(1):177-181. doi:10.1016/j.juro.2008.09.019
19. Brandao LF, Autorino R, Zargar H, et al. Robotic ileal ureter: a completely intracorporeal technique. Urology. 2014;83(4):951-954. doi:10.1016/j.urology.2013.11.035
20. Yang K, Wang X, Xu C, et al. Totally intracorporeal robot-assisted unilateral or bilateral ileal ureter replacement for the treatment of ureteral strictures: technique and outcomes from a single center. Eur Urol. 2023;84(6):561-570. doi:10.1016/j.eururo.2023.04.022
21. Ji EJ, Naser-Tavakolian A, Kanabolo DL, et al. Reconstruction of a devastated ureter: multi-institutional experience with robotic intracorporeal ileal ureter replacement. Eur Urol. 2026. doi:10.1016/j.eururo.2026.01.011
22. Ubrig B, Janusonis J, Paulics L, et al. Functional outcome of completely intracorporeal robotic ileal ureteric replacement. Urology. 2018;114:193-197. doi:10.1016/j.urology.2017.11.019
23. Wang X, Chen S, Li X, et al. Robotic-assisted laparoscopic bilateral ileal ureter replacement with extracorporeal ileal segment preparation for bilateral extensive ureteral strictures: the initial experience. Urology. 2023;176:213-218. doi:10.1016/j.urology.2023.03.026
24. Afferi L, Gallioli A, Territo A, et al. Robotic ileal ureter replacement vs kidney autotransplantation for long ureteric strictures. BJU Int. 2025;135(6):1031-1038. doi:10.1111/bju.16704