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Urethrocutaneous Fistula

A urethrocutaneous fistula (UCF) is an epithelialized communication between the urethral lumen and the skin of the penis, scrotum, or perineum. It is the most common cutaneous GU fistula in male reconstructive practice and overwhelmingly a complication of hypospadias repair — incidence ranges from 2–10% for distal and up to 30% for proximal repairs depending on technique and surgeon volume.[1][2] In adults, UCF arises from urethroplasty wound breakdown, failed childhood hypospadias presenting in adulthood, perineal trauma, Fournier's sequelae, lichen sclerosus, and chronic catheterization. Repair success rates range from 71% (simple closure) to 94–95% (tunica vaginalis or scrotal flap interposition) — the central technical lever is vascularized tissue interposition that separates the urethral and skin suture lines.[5]

For tissue-graft and -flap fundamentals, see Flaps in GU Reconstruction. For the complex-fistula framework that applies to recurrent / hostile-tissue cases, see the Fistulas landing page.

Etiology​

SettingNotes
Post-hypospadias repairThe dominant cause; complication of TIP, Mathieu, onlay, or tubularized urethroplasty[1][2]
Post-urethroplasty (stricture surgery)~3–5% of urethroplasties; higher in staged procedures and after prior failed hypospadias repair[12][13]
Failed childhood hypospadias presenting in adulthoodUCF in 24% of adult-failed-hypospadias presentations[3]
TraumaStraddle injury, penetrating perineal/penile injury, pelvic fracture
InfectionPeriurethral abscess, Fournier's gangrene[16], tuberculosis[9]
Lichen sclerosus (BXO)Can present as a scrotal/penile mass with fistula; staged BMG urethroplasty often required[10][11]
Neurogenic bladderDecubitus ulcers (33%), wound infections (24%), condom catheter complications (19%), traumatic catheterization (19%); 81% ultimately require permanent diversion[8]
Urethral calculiChronic stone impaction eroding the urethra[6]
Penile piercingChronic urine exposure through the tract; can trigger lichen sclerosus[11]
CongenitalExtremely rare (~32 cases reported); defective urethral plate or abnormal infolding of the urethral groove[7][17][33][34]

Pathophysiology​

After hypospadias repair or urethroplasty, UCF reflects breakdown of the urethral closure with subsequent epithelialization of the tract. Contributing mechanisms:[14][15][3]

  • Ischemia of the neourethra (inadequate vascular supply to tubularized tissue)
  • Tension on the suture line
  • Infection or hematoma disrupting the repair
  • Inadequate "waterproofing" tissue coverage over the neourethra
  • Distal obstruction (meatal stenosis, distal stricture) raising intraluminal pressure — the single most important and modifiable factor in recurrence

After infection or necrosis (Fournier's, periurethral abscess), the urethral wall and overlying skin necrose into a confluent defect.[16]

Congenital UCF is felt to result from a defective urethral plate or abnormal infolding of the urethral groove during embryogenesis — many patients are uncircumcised at presentation, supporting the congenital rather than iatrogenic origin.[7]

Classification​

Horton, Devine, and Graham (1980) — selects the operation[4]​

TypeRepair
Early, acuteConservative — catheter drainage
Mature single — small (< 4 mm)Local primary closure
Mature single — large (> 4 mm)Rotational or advancement skin flap
Chronic, multiple, largeTissue from a distance (TVF, scrotal flap)
Severe "surgical cripples"Total urethral reconstruction

Size (Elbakry)[18]​

  • Small < 4 mm — primary closure
  • Large > 4 mm — flap coverage

Location​

  • Coronal — most common; 78% of all recurrences[18]
  • Anterior shaft, mid-shaft, penoscrotal
  • Perineal — adults, particularly after stricture surgery or Fournier's

Risk Factors After Hypospadias Repair​

A 2026 systematic review and meta-analysis (14 studies, 3,794 patients):[1]

FactorOR (95% CI)Certainty
Proximal hypospadias2.03 (1.12–3.70)Moderate
One-stage repair (vs staged)1.67 (1.05–2.67)Moderate
Shorter stenting (< 7 d)3.96 (1.88–8.37)Low
Longer urethral defect (≥ 2 cm)1.57 (1.05–2.33)Low

Other validated risk modifiers:

  • No soft tissue interposition — 21.4% vs 3.1% fistula rate (p < 0.05)[19]
  • Single-layer dartos flap vs double — 5.1% vs 0.6% (p = 0.004)[15]
  • Surgeon experience — operative complications fall substantially with volume; reoperation for proximal hypospadias reaches 50% at referral centers[2]

Notably non-significant in the meta-analysis: age at surgery, chordee severity, suture material, TIP vs other urethroplasty methods.[1]

Clinical Presentation​

  • Urinary leakage from a cutaneous opening on the penis, perineum, or scrotum
  • Abnormal stream — spraying, double or forked stream, ventral dribbling
  • Recurrent UTI
  • Skin maceration around the fistula
  • Cosmetic concerns, particularly in adolescents
  • In neurogenic-bladder adults — perineal/scrotal skin breakdown and chronic wound drainage[8]

Diagnostic Evaluation​

  1. Physical exam — number, size, and location of openings; quality of penile skin and prior surgical scars
  2. Urethral calibration / cystoscopy — mandatory to exclude distal obstruction (meatal stenosis, distal stricture). Distal obstruction is the dominant driver of recurrence and must be corrected before or at the time of fistula repair.[18][20]
  3. Retrograde urethrogram (RUG) — fistula site and concurrent stricture
  4. Dye injection (methylene blue or povidone) per meatus — identifies all openings when multiple fistulas suspected[20]
  5. VCUG — concurrent pathology

Management​

Timing and conservative management​

  • A minimum of 6 months between the inciting surgery and fistula repair allows tissue maturation.[18][21]
  • ~10% of UCFs close spontaneously or after a single dilation; conservative catheter drainage is reasonable for small, early fistulas.[14][21]

Prerequisite — rule out and treat distal obstruction​

The most important preoperative principle: a UCF distal to an unrelieved obstruction will recur.[18][20]

Surgical technique selection​

TechniqueBest fitSuccess
Simple primary closureSmall (< 4 mm) shaft fistula, single, no scarring71–79%[18][22][5][29]
De-epithelialized / full-thickness skin advancement flapSimple and complex fistulas; outpatient feasible96% overall (4.3% simple failure; 11.1% complex)[24]
Purse-string closureSmall to mid-sized93% (vs 70% linear, p = 0.015)[21]
PATIO repair (Preserve And Turn Inside Out)Coronal and subcoronal; technically straightforward, day-case93.5% pooled[5][25]
Multilayer closure with longitudinal relaxing incisionTension-prone shaft fistulasReduces tension-related recurrence[26]
Traction-assisted dissection + spermatic-fascia or TVF coverageRecurrent fistulas100% in 35 fistulas / 26 patients (12 recurrent), mean 7.4 yr[27]
Tunica vaginalis flap (TVF) interpositionRecurrent, proximal hypospadias, redo94.3%[5][20][28]
Scrotal flapRecurrent, penoscrotal location94.6%[5]

Adult catheterless repair is feasible — in 96 adults, success was 94% without catheter vs 93% with, with fewer wound infections in the uncatheterized group.[23]

Tissue Interposition — the central technical lever​

A 2023 systematic review and meta-analysis (2,886 patients, 71 studies) ranked waterproofing layers:[5]

Waterproofing layerPooled success
Tunica vaginalis flap (TVF)94.3%
Scrotal flap94.6%
PATIO repair93.5%
Biomaterials / dermal substitutes92%
Double dartos flaps81%
Single dartos flap78.8%
Simple primary closure73.2%
Skin-based flaps54.5%
Biocompatible adhesives56.5%

Fahmy algorithm (Eur Urol 2016) — flap selection[15]​

SettingPreferred coverage
Distal hypospadias — primaryDouble dartos flap (0.6% vs 5.1% with single, p = 0.004)
Proximal hypospadias — primaryTVF (single dartos has 8.8% fistula rate)
Repeat / redo casesTVF (6.4% vs 18.6% for dartos, p = 0.020)
Fistula repair after primary hypospadiasTVF preferred (5.1% vs 12.2% recurrence with dartos)

TVF — technique and outcomes​

  • Harvested from the ipsilateral testis through a small scrotal incision; mobilized on its vascular pedicle through a subcutaneous tunnel to the penile shaft[20][28]
  • Provides well-vascularized, elastic, durable interposition
  • 100% success in recurrent fistulas (14 patients, mean 2.4 prior failed closures, 44-mo follow-up)[20]
  • Randomized comparison vs dartos for primary TIP: UCF rate 4.9% (TVF) vs 20.9% (dartos), p = 0.029[30]
  • Donor-site complication: testicular ascent in ~7% at 12 months[30]

UCF in Adults​

Adult UCF is operationally distinct from the pediatric setting.

After failed childhood hypospadias repair[3]​

  • Adults presenting with prior hypospadias complications: urethral stricture 72%, UCF 24%, persistent hypospadias 14%, hair in urethra 12%, severe chordee 14%
  • Initial surgical success ~50%; overall success after additional procedures ~76%
  • Operations needed: staged urethroplasty, penile skin flap, BMG onlay, fistula closure, perineal urethrostomy

After urethroplasty for stricture[12][13]​

  • UCF in ~3–5% of urethroplasties
  • Higher in staged procedures (21–23% revision) and in failed-hypospadias-related strictures (4.7% fistula rate; 34% overall failure of urethroplasty for failed-hypospadias strictures, rising to 57% at 10 years)

In neurogenic bladder[8]​

  • 81% ultimately require permanent urinary diversion (suprapubic tube, ileal conduit, or perineal urethrostomy)
  • Surgical repair has poor durability — counsel about probable need for diversion

Catheterless adult repair[23]​

  • Local-anesthesia repair without catheter is effective, safe, and cost-efficient

Prevention (at primary hypospadias repair)​

The fistula rate is set by what you do at the index operation more than by anything you do later:[1][15][19][31][32]

  1. Soft tissue interposition over the neourethra — fistula rate falls from 21.4% to 3.1% (p < 0.05)[19]
  2. Double dorsal dartos flap for distal hypospadias — 0% vs 9.8% with single flap (p = 0.024)[32]
  3. Cover flap reduces fistula regardless of severity — protective effect grows with proximal disease (OR 2.6 anterior, 5.5 midpenile, 7.1 posterior)[31]
  4. Staged repair for proximal hypospadias — one-stage carries OR 1.67 for fistula[1]
  5. Stenting ≥ 7 days in high-risk patients — shorter stenting OR 3.96[1]
  6. Meticulous gentle tissue handling, tension-free closure, watertight anastomosis
  7. Surgeon volume — operative complications fall with experience[2]

Congenital UCF​

Extremely rare (~32 reported cases). Presents in isolation or with chordee, hypospadias, or urethral duplication. Repair is individualized — primary closure, Thiersch–Duplay urethroplasty, pedicle flap, hinged flap, or island pedicle tube/onlay urethroplasty depending on the anatomic defect.[7][17][33][34]

Operative Principles​

  • Exclude and treat distal obstruction first — the single most-cited cause of recurrence[18]
  • Wait ≥ 6 months from the inciting surgery
  • Tissue interposition is the central technical lever — TVF or scrotal flap for recurrent, proximal, or redo cases; double dartos for primary distal hypospadias[5][15]
  • Avoid overlapping suture lines between urethral and skin layers
  • Simple closure works for small (< 4 mm) shaft fistulas only[18]
  • In neurogenic-bladder patients, repair has poor durability — discuss permanent diversion early[8]

References​

1. Khosravi R, Alizadeh H, Khosarvi H. "Risk factors for urethrocutaneous fistula following primary hypospadias repair in children: a systematic review and meta-analysis." J Pediatr Surg. 2026:162928. doi:10.1016/j.jpedsurg.2026.162928

2. Diamond DA, Chan IHY, Holland AJA, et al. "Advances in paediatric urology." Lancet. 2017;390(10099):1061–1071. doi:10.1016/S0140-6736(17)32282-1

3. Myers JB, McAninch JW, Erickson BA, Breyer BN. "Treatment of adults with complications from previous hypospadias surgery." J Urol. 2012;188(2):459–463. doi:10.1016/j.juro.2012.04.007

4. Horton CE, Devine CJ, Graham JK. "Fistulas of the penile urethra." Plast Reconstr Surg. 1980;66(3):407–418.

5. Choudhury P, Saroya KK, Jain V, et al. "'Waterproofing layers' for urethrocutaneous fistula repair after hypospadias surgery: evidence synthesis with systematic review and meta-analysis." Pediatr Surg Int. 2023;39(1):165. doi:10.1007/s00383-023-05405-1

6. Zeng M, Zeng F, Wang Z, et al. "Urethral calculi with a urethral fistula: a case report and review of the literature." BMC Res Notes. 2017;10(1):444. doi:10.1186/s13104-017-2798-z

7. Caldamone AA, Chen SC, Elder JS, et al. "Congenital anterior urethrocutaneous fistula." J Urol. 1999;162(4):1430–1432.

8. Raup VT, Eswara JR, Weese JR, Potretzke AM, Brandes SB. "Urinary-cutaneous fistulae in patients with neurogenic bladder." Urology. 2015;86(6):1222–1226. doi:10.1016/j.urology.2015.07.057

9. Bhari N, Jangid BL, Singh S, et al. "Urethrocutaneous fistula: a rare presentation of penile tuberculosis." Int J STD AIDS. 2017;28(1):97–99. doi:10.1177/0956462416647624

10. Kumar S, Nagappa B, Ganesamoniv R. "Extensive balanitis xerotica obliterans of urethrocutaneous fistula presenting as mass in scrotum." Urology. 2010;76(2):332–333. doi:10.1016/j.urology.2009.09.005

11. Chan S, Watchorn RE, Muneer A, Bunker CB. "Lichen sclerosus following genital piercing." Int J STD AIDS. 2022;33(5):522–524. doi:10.1177/09564624221079068

12. Verla W, Van Nieuwenhuyse F, Hoebeke P, et al. "Urethroplasty for failed hypospadias repair related strictures in adults: a retrospective analysis with long-term follow-up." Urology. 2020;143:248–254. doi:10.1016/j.urology.2020.05.070

13. Joseph JV, Andrich DE, Leach CJ, Mundy AR. "Urethroplasty for refractory anterior urethral stricture." J Urol. 2002;167(1):127–129.

14. Zagula EM, Braren V. "Management of urethrocutaneous fistulas following hypospadias repair." J Urol. 1983;130(4):743–745. doi:10.1016/s0022-5347(17)51434-2

15. Fahmy O, Khairul-Asri MG, Schwentner C, et al. "Algorithm for optimal urethral coverage in hypospadias and fistula repair: a systematic review." Eur Urol. 2016;70(2):293–298. doi:10.1016/j.eururo.2015.12.047

16. Kim SJ, Lee J, Park CH, et al. "Urethral defect due to periurethral abscess treated with a tunica vaginalis flap: a case report." Medicine (Baltimore). 2018;97(46):e13249. doi:10.1097/MD.0000000000013249

17. Goldstein M. "Congenital urethral fistula with chordee." J Urol. 1975;113(1):138–140. doi:10.1016/s0022-5347(17)59427-6

18. Elbakry A. "Management of urethrocutaneous fistula after hypospadias repair: 10 years' experience." BJU Int. 2001;88(6):590–595. doi:10.1046/j.1464-4096.2001.02390.x

19. Seo S, Ochi T, Yazaki Y, et al. "Soft tissue interposition is effective for protecting the neourethra during hypospadias surgery and preventing postoperative urethrocutaneous fistula: a single surgeon's experience of 243 cases." Pediatr Surg Int. 2015;31(3):297–303. doi:10.1007/s00383-015-3655-6

20. Landau EH, Gofrit ON, Meretyk S, et al. "Outcome analysis of tunica vaginalis flap for the correction of recurrent urethrocutaneous fistula in children." J Urol. 2003;170(4 Pt 2):1596–1599. doi:10.1097/01.ju.0000084661.05347.58

21. Bloesch S, Misra D, Mohd-Amin AT. "Management of urethral fistula after hypospadias repair with particular reference to purse-string sutures: a 24-year review." Pediatr Surg Int. 2022;38(6):919–925. doi:10.1007/s00383-022-05109-y

22. Dekalo S, Ben-David R, Bar-Yaakov N, et al. "In support of a simple urethrocutaneous fistula closure technique following hypospadias repair." Urology. 2020;143:212–215. doi:10.1016/j.urology.2020.06.015

23. Sen B, Adayener C, Akyol I. "Repairing urethrocutaneous fistula in adults: is a catheter necessary?" Urology. 2007;70(2):239–241. doi:10.1016/j.urology.2007.04.013

24. Santangelo K, Rushton HG, Belman AB. "Outcome analysis of simple and complex urethrocutaneous fistula closure using a de-epithelialized or full thickness skin advancement flap for coverage." J Urol. 2003;170(4 Pt 2):1589–1592. doi:10.1097/01.ju.0000084624.17496.29

25. Malone PR. "Urethrocutaneous fistula: preserve the tract and turn it inside out: the PATIO repair." BJU Int. 2009;104(4):550–554. doi:10.1111/j.1464-410X.2009.08350.x

26. Chen W, Ma N, Wang W, Ju M. "The application of multilayer direct closure with a longitudinal relaxing incision in urethrocutaneous fistula repair." Ann Plast Surg. 2020;84(3):317–321. doi:10.1097/SAP.0000000000002056

27. Ochi T, Seo S, Yazaki Y, et al. "Traction-assisted dissection with soft tissue coverage is effective for repairing recurrent urethrocutaneous fistula following hypospadias surgery." Pediatr Surg Int. 2015;31(2):203–207. doi:10.1007/s00383-014-3652-1

28. Routh JC, Wolpert JJ, Reinberg Y. "Tunneled tunica vaginalis flap is an effective technique for recurrent urethrocutaneous fistulas following tubularized incised plate urethroplasty." J Urol. 2006;176(4 Pt 1):1578–1580. doi:10.1016/j.juro.2006.06.032

29. Muruganandham K, Ansari MS, Dubey D, et al. "Urethrocutaneous fistula after hypospadias repair: outcome of three types of closure techniques." Pediatr Surg Int. 2010;26(3):305–308. doi:10.1007/s00383-009-2490-z

30. Ramez M, Hashem A, Bazeed M, Dawaba MS, Helmy TE. "Tunica vaginalis or dartos as second layer coverage for distal and mid-shaft penile hypospadias, quo vadis?" World J Urol. 2025;43(1):78. doi:10.1007/s00345-024-05419-x

31. Tessier B, Sfar S, Garnier S, et al. "A cover flap reduces the rate of fistula after urethroplasty whatever the severity of hypospadias." World J Urol. 2021;39(7):2691–2695. doi:10.1007/s00345-020-03489-1

32. Mekki M, Fredj MB, Messaoud M, et al. "The effectiveness of double dorsal dartos flap for urethroplasty coverage in distal hypospadias repair: a single surgeon approach to preventing urethrocutaneous fistula." Int J Urol. 2024;31(12):1380–1384. doi:10.1111/iju.15572

33. Nakane A, Hayashi Y, Kojima Y, et al. "Congenital urethrocutaneous fistula." Int J Urol. 2000;7(9):343–344. doi:10.1046/j.1442-2042.2000.00202.x

34. Akman RY, Cam K, Akyuz O, Erol A. "Isolated congenital urethrocutaneous fistula." Int J Urol. 2005;12(4):417–418. doi:10.1111/j.1442-2042.2005.01050.x