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Urinary Fistula After Kidney Transplant

Urinary fistula after kidney transplantation is the most common urological complication of the early post-transplant period, with an incidence of 1.1–8.9% across large series, and is overwhelmingly driven by ischemic necrosis of the distal transplant ureter rather than technical anastomotic failure.[1][2][3][4] The transplant ureter's vulnerability is anatomic: unlike the native ureter, it depends solely on a hilar branch of the renal artery for its blood supply, so the distal segment is the watershed.

See also: The Ureters, Fistulas landing page, Ureteral Reimplantation, Boari Flap & Psoas Hitch.

Definition and Classification​

A post-transplant urinary fistula is abnormal extravasation of urine from the transplant collecting system, ureter, or ureterovesical anastomosis.[4][5]

AxisCategories
TimingEarly (≤ 30 days; ~79% of urologic complications, predominantly fistulae) vs. late (> 30 days; viral, ischemic, or stricture-progression-related)[4][6]
LocationUreteral (most common; distal ureter or ureterovesical anastomosis), vesical (cystotomy site), caliceal (rare; renal pelvis or calyx)[7]
SeverityMinor (small extravasation, may respond to conservative management) vs. major (large-volume leak, urinoma, requires intervention)

Etiology and Pathogenesis​

The fundamental vulnerability of the transplant ureter is its tenuous blood supply. Unlike the native ureter (which receives blood from renal, gonadal, iliac, and vesical arteries), the transplant ureter is fed solely from the renal hilum via a branch of the renal artery running along the ureteral adventitia. The distal ureter is therefore the watershed segment most susceptible to ischemic necrosis.[8][9]

Primary causes​

  1. Distal ureteral ischemic necrosis — the dominant cause, accounting for 76.7% of urinary fistulae in a 1,223-transplant series.[1] Mechanisms:
    • Inadequate preservation of periureteral tissue and blood supply during donor nephrectomy
    • Excessive skeletonization during bench preparation
    • Ligation of accessory lower-pole arteries that may supply the distal ureter and collecting system[2]
    • Prolonged cold ischemia time
  2. Technical factors at the anastomosis — tension on the ureterovesical anastomosis, inadequate mucosal apposition, suture-line disruption.
  3. Delayed graft function (DGF) — independently associated with ureteral necrosis (p = 0.016), likely through exacerbation of ischemic injury.[6]
  4. Donor age — independently correlated with ureteral necrosis (p = 0.041).[6]
  5. Renal-artery multiplicity — the only independent risk factor for urologic complications in one multivariate analysis (aHR 2.4, 95% CI 1.1–5.1, p = 0.02). Accessory vessels may be the sole supply to the distal ureter if ligated.[10]
  6. Viral infections — CMV is significantly more common in patients with ureteral necrosis (p = 0.001); histology of necrotic ureters has shown CMV inclusions in 4 of 25 cases and BK virus inclusions in 2 of 25.[6] BK polyomavirus more commonly drives stenosis than fistula but can contribute to ureteral injury through direct uroepithelial cytopathic effects.[11][12]
  7. Other — male recipient sex (HR 2.0, p < 0.05), retransplantation (first transplant protective, HR 0.4, p < 0.05), and cadaveric donor.[4][13]

Anastomotic Technique and Fistula Risk​

The choice of ureterovesical anastomosis influences fistula rate.[8][9][14]

TechniqueDescriptionComplication rateNotes
Lich-Gregoir (extravesical)Mucosal nick, ureteral anastomosis from outside the bladder, submucosal tunnel by seromuscular reapproximation6.15% overallLower complication rate, less technically demanding; slight residual leak / reflux risk[1][2][14]
Leadbetter-Politano (transvesical)Serosal incision, intramural submucosal tunnel, anastomosis from inside the bladder8.33% overallHigher obstruction risk; more technically demanding[1][2][14]
Ureteroureterostomy (UU)End-to-end or end-to-side anastomosis of donor ureter to native ureter1.5–4.7%Lower fistula rate (1.5% vs. 4.1%, p < 0.05); preserves a non-refluxing system; useful in difficult bladders or as salvage[1][15]

A meta-analysis of 26 studies confirmed a significantly lower urinary leakage rate with Lich-Gregoir vs. Leadbetter-Politano (RR 0.47, 95% CI 0.30–0.75); Lich-Gregoir is now the most widely used technique.[14]

A modified extravesical technique (mobilized bladder, longer ureteral spatulation, inclusion of bladder mucosa with detrusor in the anastomosis) achieved a urologic-complication rate of 1.4% (7/500) without routine stenting.[17]

Prophylactic Ureteral Stenting​

Evidence supporting routine stenting​

A 2024 Cochrane systematic review (11 RCTs, 1,834 participants) found that prophylactic stenting probably produces a large reduction in major urological complications:[18]

OutcomeRR (95% CI)
Combined leak + obstruction0.30 (0.16–0.55); NNT = 17
Urine leak0.26 (0.12–0.56)
Ureteric obstruction0.47 (0.25–0.87)

Evidence certainty: moderate (GRADE). A 2025 meta-analysis of 16 RCTs (2,486 patients) corroborated these findings (urine leak RR 0.25, obstruction / stricture RR 0.42).[19]

The trade-off — UTI risk​

Both the Cochrane review and a propensity-matched NSQIP analysis (3,407 recipients) consistently show stenting raises UTI rates:[19][20]

  • Stented vs. non-stented UTI: 7.4% vs. 3.2% (p < 0.05)[20]
  • Pooled RR for UTI with stenting: 1.41 (1.08–1.84)[19]

The NSQIP analysis found no difference in major urological complications between matched stented and non-stented patients (leak 1.0% vs 1.0%; stenosis 1.7% vs 1.5%), suggesting that with refined contemporary technique the marginal benefit of universal stenting may be diminishing.[20]

Current practice​

Combining Lich-Gregoir with routine double-J stenting reduced fistula rates from 7% to 2% (p = 0.0001) in a 1,011-transplant single-center series.[21]

Clinical Presentation​

Urinary fistula typically presents within the first 1–3 weeks post-transplant (mean onset 6 days, range 3–20).[1]

  • Rising serum creatinine — often the first sign
  • Decreased urine output — easily confused with delayed graft function or rejection
  • Wound drainage — clear or serosanguinous fluid from the surgical incision
  • Perigraft fluid collection (urinoma) on ultrasound
  • Pain and swelling over the graft site
  • Fever and signs of sepsis when the urinoma is infected (~20% of fistulae)[22]
  • Ipsilateral scrotal or labial edema from urine tracking along tissue planes[5][23][24]

Evaluation​

Initial evaluation​

  • Ultrasound — first-line; detects perigraft collections (urinoma, lymphocele, hematoma) with ~67% sensitivity for leak but cannot reliably distinguish urinoma from lymphocele or seroma.[24][25]
  • Fluid analysis — aspiration of the collection with measurement of creatinine concentration; fluid creatinine far exceeding serum creatinine confirms a urine leak.

Confirmatory imaging​

ModalityRole
Antegrade pyelography (via PCN)Most accurate test, 83–100% sensitivity; directly demonstrates the leak site[25][26]
Nuclear renography (MAG3 / DTPA)Functional baseline and graft-dysfunction signal; lower direct-leak sensitivity (~33%)[24][25]
CT urographyShows extravasation, urinoma, and complications; both nephrographic and delayed phases recommended
Retrograde cystographyIdentifies vesical leaks at the cystotomy
Cystoscopy with retrograde pyelographyOften technically difficult given transplant ureteral anatomy

Management​

A stepwise approach scaled to leak size and location, infection, and ureteral viability.[1][2][9][22]

1. Conservative / minimally invasive​

Suitable for small leaks without significant urinoma or infection.

  • Prolonged urethral catheter drainage for 1–2 weeks decompresses the bladder and offloads the anastomosis. Conservative management succeeded in 42.4% of vesical fistulae but 0% of ureteral fistulae in one series.[22]
  • Percutaneous nephrostomy ± antegrade ureteral stenting is the principal minimally invasive intervention:[26][27][28]
    • Leak closure rate 59–87%[26][28]
    • Mean duration of urinary diversion 68 days[26]
    • PCN is recommended in the ACR Appropriateness Criteria for transplant urinary obstruction / leak[27]
  • Percutaneous drainage of urinoma when a significant collection is present (essential if infected).
  • Ureteral catheterization with an 8 F Foley has been described for complicated fistulae unsuitable for primary repair, with 80% success in one small series (4/5).[22]

2. Surgical reconstruction​

Required for most ureteral fistulae, particularly those driven by distal ureteral necrosis, and for leaks refractory to conservative management.[1][2][9][29]

  • Redo ureteroneocystostomy — re-excision of necrotic distal ureter with reimplantation; the most common reconstruction (36.6%) in a multicenter series.[29] See also Ureteral Reimplantation.
  • Ureteroureterostomy with the native ureter — anastomosis of the transplant renal pelvis or proximal ureter to the ipsilateral native ureter; an excellent salvage option, with > 90% success and a 3.9% reintervention rate.[9][30] Minimally invasive (robotic / laparoscopic) pyeloureterostomy or UU is feasible and safe with no obstruction or leak at mean 20.9-month follow-up.[30] Native ureters are used in > two-thirds of pediatric ureteral reconstructions after transplant.[31]
  • Boari flap with psoas hitch for extensive ureteral defects where direct reimplantation is not possible — preserves graft function without stricture recurrence in published series.[9] See also Boari Flap & Psoas Hitch.
  • Pyelovesicostomy — direct anastomosis of renal pelvis to bladder; ~80% long-term success in complex cases.[9]
  • Pedicled greater-omentum graft — dedicated to recurrent fistulae. The omentum is mobilized on its vascular pedicle and wrapped around the anastomotic site, providing well-vascularized tissue coverage. 100% success at first attempt in 13 patients with recurrent fistulae over 1–7 years of follow-up; in a larger series, omentum successfully treated 21 fistulae including 10 recurrent.[1][32]
  • Ureteroenterostomy (anastomosis to an ileal conduit or other intestinal segment) — reserved for patients with nonfunctioning urinary tracts; comparable 5-year graft survival (63%) but higher infection rates (65%).[9]
  • Negative pressure wound therapy (NPWT / VAC) — described as an adjunct for healing complex urinary fistula wounds after transplantation into an ileal conduit.[33]
  • Transplant nephrectomy — last resort when extensive pelvic and ureteral necrosis precludes reconstruction; needed in only 1 of 43 fistulae in one large series.[1]

Reconstructive vs. palliative for ureteral stenosis​

A recent EAU-YAU multicenter study compared surgical reconstruction (n = 30) to palliative permanent ureteral stenting (n = 24) for post-transplant ureteral stenosis: reconstruction achieved definitive treatment in 86.7% (4/30 failures), while palliative stenting was associated with significant eGFR degradation over time (43.5 → 32.0 mL/min/1.73 m², p < 0.05).[29]

Prevention​

Key strategies to minimize post-transplant urinary fistula:[2][8][9][17][21]

  1. Preserve periureteral tissue — maintain the "golden triangle" of tissue around the renal hilum and proximal ureter during donor nephrectomy; avoid ureteral skeletonization.
  2. Preserve accessory lower-pole arteries — they may be the sole blood supply to the distal ureter and collecting system.[2]
  3. Keep the donor ureter short — use only as much length as needed for a tension-free anastomosis; excess length increases the ischemic at-risk segment.
  4. Use the Lich-Gregoir technique — fewer urological complications than Leadbetter-Politano (RR 0.47 for leak).[14]
  5. Prophylactic ureteral stenting — ~74% leak reduction (RR 0.26); recommended by most centers.[18][19]
  6. Adequate bladder decompression with postoperative Foley drainage to prevent intravesical pressure buildup at the anastomosis.[23]
  7. Minimize cold ischemia time — prolonged ischemia exacerbates ureteral injury.
  8. CMV and BK virus surveillance — early detection and treatment may reduce late ureteral complications.[6][34]

Outcomes​

Despite the morbidity, long-term graft and patient survival are generally not compromised when the complication is recognized promptly and managed appropriately.[6][16]

OutcomeResult
10-year patient survival87% (necrosis) vs. 86% (controls) — NS[6]
10-year graft survival66% (necrosis) vs. 58% (controls) — NS[6]
Discharged with functioning graft after treatment95%[16]
Graft loss from urological complications0% in several large contemporary series[1][13]
Historical graft loss / mortality with delayed diagnosis10–15% graft loss / up to 15% mortality[2]

Key Points​

FeatureDetail
Incidence1.1–8.9% of kidney transplants[1][2]
Most common causeDistal ureteral ischemic necrosis (76.7%)[1]
Mean onset6 days post-transplant (range 3–20)[1]
Key risk factorsDonor age, DGF, renal-artery multiplicity, male recipient sex, retransplantation[3][4][6]
Best anastomotic techniqueLich-Gregoir (lowest leak rate)[14]
Prophylactic stenting effect~74% reduction in leak (RR 0.26); higher UTI rate[18][19]
Conservative success42% (vesical) → 59–87% with PCN[22][26][28]
Surgical success87–100% with appropriate reconstruction[1][30][32]
Graft loss from fistulaRare (< 5%) in contemporary series[1][3][16]
Long-term graft survival impactNo significant difference vs. controls[6]

References​

1. Nie ZL, Zhang KQ, Li QS, et al. "Treatment of Urinary Fistula After Kidney Transplantation." Transplant Proc. 2009;41(5):1624–1626. doi:10.1016/j.transproceed.2008.10.103

2. Li Marzi V, Filocamo MT, Dattolo E, et al. "The Treatment of Fistulae and Ureteral Stenosis After Kidney Transplantation." Transplant Proc. 2005;37(6):2516–2517. doi:10.1016/j.transproceed.2005.06.049

3. Yamanaka K, Kakuta Y, Nakazawa S, et al. "Surgical and Infectious Complications Following Kidney Transplantation: A Contemporary Review." J Clin Med. 2025;14(10):3307. doi:10.3390/jcm14103307

4. Neri F, Tsivian M, Coccolini F, et al. "Urological Complications After Kidney Transplantation: Experience of More Than 1,000 Transplantations." Transplant Proc. 2009;41(4):1224–1226. doi:10.1016/j.transproceed.2009.03.044

5. Di Carlo HN, Darras FS. "Urologic Considerations and Complications in Kidney Transplant Recipients." Adv Chronic Kidney Dis. 2015;22(4):306–311. doi:10.1053/j.ackd.2015.04.003

6. Karam G, Maillet F, Parant S, Soulillou JP, Giral-Classe M. "Ureteral Necrosis After Kidney Transplantation: Risk Factors and Impact on Graft and Patient Survival." Transplantation. 2004;78(5):725–729. doi:10.1097/01.tp.0000131953.13414.99

7. Torricelli FC, Piovesan AC, Antonopoulos IM, et al. "Caliceal-Cutaneous Fistula After Kidney Transplantation." Urology. 2012;79(5):e71. doi:10.1016/j.urology.2012.01.018

8. Nikolic B, Rose SC, Ortiz J, et al. "Standards of Reporting for Interventional Radiology Treatment of Renal and Pancreatic Transplantation Complications." J Vasc Interv Radiol. 2012;23(12):1547–1556. doi:10.1016/j.jvir.2012.09.009

9. Novacescu D, Abol-Enein H, Latcu S, et al. "Ureteric Complications and Urinary Tract Reconstruction Techniques in Renal Transplantation: A Surgical Essay." J Clin Med. 2025;14(12):4129. doi:10.3390/jcm14124129

10. Rahnemai-Azar AA, Gilchrist BF, Kayler LK. "Independent Risk Factors for Early Urologic Complications After Kidney Transplantation." Clin Transplant. 2015;29(5):403–408. doi:10.1111/ctr.12530

11. Kotla SK, Kadambi PV, Hendricks AR, Rojas R. "BK Polyomavirus — Pathogen, Paradigm and Puzzle." Nephrol Dial Transplant. 2021;36(4):587–593. doi:10.1093/ndt/gfz273

12. Egli A, Binggeli S, Bodaghi S, et al. "Cytomegalovirus and Polyomavirus BK Posttransplant." Nephrol Dial Transplant. 2007;22 Suppl 8:viii72–viii82. doi:10.1093/ndt/gfm648

13. Buresley S, Samhan M, Moniri S, Codaj J, Al-Mousawi M. "Postrenal Transplantation Urologic Complications." Transplant Proc. 2008;40(7):2345–2346. doi:10.1016/j.transproceed.2008.06.036

14. Alberts VP, Idu MM, Legemate DA, Laguna Pes MP, Minnee RC. "Ureterovesical Anastomotic Techniques for Kidney Transplantation: A Systematic Review and Meta-Analysis." Transpl Int. 2014;27(6):593–605. doi:10.1111/tri.12301

15. 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

16. Illésy L, Kovács DÁ, Fedor R, et al. "Ureteral Complications Requiring Intervention After Kidney Transplant: A Single-Center Experience." Transplant Proc. 2022;54(9):2578–2583. doi:10.1016/j.transproceed.2022.10.045

17. Ciancio G, Farag A, Gonzalez J, Vincenzi P, Gaynor JJ. "Results of a Previously Unreported Extravesical Ureteroneocystostomy Technique Without Ureteral Stenting in 500 Consecutive Kidney Transplant Recipients." PLoS One. 2021;16(1):e0244248. doi:10.1371/journal.pone.0244248

18. Patterson LG, Tingle SJ, Rix DA, Manas DM, Wilson CH. "Routine Intraoperative Ureteric Stenting for Kidney Transplant Recipients." Cochrane Database Syst Rev. 2024;7:CD004925. doi:10.1002/14651858.CD004925.pub4

19. Yin S, Hao X, Cai X, et al. "Do Ureteral Stents Improve Clinical Outcomes in Renal Transplantation? A Systematic Review and Meta-Analysis Comparing Stented and Non-Stented Anastomosis Techniques." PeerJ. 2026;14:e20665. doi:10.7717/peerj.20665

20. Amara D, Melehy A, Parekh J, et al. "Prophylactic Ureteral Stenting in Kidney Transplantation: A Multivariable and Propensity Score–Matched Analysis of 3407 Recipients From NSQIP Transplant." Transplantation. 2026;110(5):e1100–e1111. doi:10.1097/TP.0000000000005660

21. Moreno-Alarcón C, López-Cubillana P, López-González PÁ, et al. "Lich-Gregoir Technique and Routine Use of Double J Catheter as the Best Combination to Avoid Urinary Complications in Kidney Transplantation." Transplant Proc. 2014;46(1):167–169. doi:10.1016/j.transproceed.2013.12.002

22. Suaid HJ, Cassini MF, Tucci S, et al. "Therapeutic Option for Infected Urinary Tract Fistulas in Renal Transplantation." Transplant Proc. 2010;42(2):479–482. doi:10.1016/j.transproceed.2010.01.029

23. Goodfellow M, Thompson ER, Tingle SJ, Wilson C. "Early Versus Late Removal of Urinary Catheter After Kidney Transplantation." Cochrane Database Syst Rev. 2023;7:CD013788. doi:10.1002/14651858.CD013788.pub2

24. Erbas B. "Peri- and Postsurgical Evaluations of Renal Transplant." Semin Nucl Med. 2017;47(6):647–659. doi:10.1053/j.semnuclmed.2017.07.002

25. Smith TP, Hunter DW, Letourneau JG, et al. "Urine Leaks After Renal Transplantation: Value of Percutaneous Pyelography and Drainage for Diagnosis and Treatment." AJR Am J Roentgenol. 1988;151(3):511–513. doi:10.2214/ajr.151.3.511

26. Matalon TA, Thompson MJ, Patel SK, et al. "Percutaneous Treatment of Urine Leaks in Renal Transplantation Patients." Radiology. 1990;174(3 Pt 2):1049–1051. doi:10.1148/radiology.174.3.174-3-1049

27. Scheidt MJ, Hohenwalter EJ, Pinchot JW, et al. "ACR Appropriateness Criteria® Radiologic Management of Urinary Tract Obstruction." J Am Coll Radiol. 2020;17(5S):S281–S292. doi:10.1016/j.jacr.2020.01.039

28. Fontaine AB, Nijjar A, Rangaraj R. "Update on the Use of Percutaneous Nephrostomy / Balloon Dilation for the Treatment of Renal Transplant Leak / Obstruction." J Vasc Interv Radiol. 1997;8(4):649–653. doi:10.1016/s1051-0443(97)70625-0

29. Lucignani G, Rivetti A, Prudhomme T, et al. "Reconstructive Versus Palliative Management of Ureteral Stenosis After Kidney Transplant: An EAU-YAU Kidney Transplantation Working Group Collaboration." World J Urol. 2025;43(1):439. doi:10.1007/s00345-025-05824-w

30. Yang KK, Moinzadeh A, Sorcini A. "Minimally-Invasive Ureteral Reconstruction for Ureteral Complications of Kidney Transplants." Urology. 2019;126:227–231. doi:10.1016/j.urology.2019.01.002

31. Serrell EC, Su R, O'Kelly F, Semanik M, Farhat WA. "The Utility of Native Ureter in the Management of Ureteral Complications in Children After Renal Transplantation." Pediatr Transplant. 2021;25(7):e14051. doi:10.1111/petr.14051

32. Ye J, Li Q, Liu R, et al. "Pedicled Greater Omentum Graft: A New Technique to Repair Recurrent Urinary Fistulae After Kidney Transplantation." Cell Biochem Biophys. 2012;62(1):69–72. doi:10.1007/s12013-011-9260-y

33. Heap S, Mehra S, Tavakoli A, et al. "Negative Pressure Wound Therapy Used to Heal Complex Urinary Fistula Wounds Following Renal Transplantation Into an Ileal Conduit." Am J Transplant. 2010;10(10):2370–2373. doi:10.1111/j.1600-6143.2010.03237.x

34. Hariharan S, Israni AK, Danovitch G. "Long-Term Survival After Kidney Transplantation." N Engl J Med. 2021;385(8):729–743. doi:10.1056/NEJMra2014530