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Tunica Vaginalis Flap for UCF Repair and Reconstruction

A pedicled tunica vaginalis flap (TVF) supplies vascularized tissue over a urethral repair, especially when local penile coverage is scarred or inadequate. It is a useful option for selected recurrent urethrocutaneous fistulas (UCFs), but pooled series do not establish a universal first-choice operation or guarantee closure.[1][2][3]

Compare Local Skin Advancement, Double Dartos, Scrotal Flaps, PATIO and the male fistula atlas.

Anatomy and selection​

The flap uses the parietal tunica vaginalis, preserving the testis, epididymis, vas and testicular vessels. The vascular pedicle is maintained with its fascial attachments. This donor tissue is separate from penile dartos, but prior inguinal or scrotal surgery can affect availability, dissection and perfusion.[3][11]

Assess fistula anatomy, distal obstruction, associated urethral loss, local tissue quality and the donor side before selecting a flap. Previous orchiopexy or hernia repair is a reason for careful planning rather than an automatically proven absolute contraindication. The 2025 randomized trial excluded those patients; it therefore cannot establish safety or feasibility in that subgroup.[3][11]

Keep three uses distinct:

  • Interposition: tissue covers an already closed urethra to separate suture lines.
  • Substitution urethroplasty: tunica forms part of the urinary lumen, with different healing and stricture risks.
  • Corporal patching: tunica covers a ventral corporotomy during curvature correction; it is not urethral lining.[3][4][8]

A free tunica graft has no retained pedicle and should not be described as a vascularized flap.

Operative principles for UCF coverage​

  1. Map and evaluate the urethra. Identify all fistulas and assess the distal lumen. Calibration or endoscopy may help when appropriate; intraluminal dye use is a technique-specific choice, not a prerequisite for every repair.
  2. Repair the urinary defect. Close the fistula or perform the required urethral reconstruction. Landau's series used primary closure in 12 children and an onlay island reconstruction in two.
  3. Expose the donor tissue. Access may use a scrotal incision or the penoscrotal field after penile degloving, depending on the operation. Protect the cord and testicular structures.
  4. Raise the flap with a viable pedicle. Mobilize the parietal tunica and supporting fascial tissue to achieve adequate reach without compromising perfusion.
  5. Transfer and secure coverage. A subcutaneous tunnel may be used. Prevent pedicle compression, twist, traction and excessive bulk around the urethra or glans.
  6. Reassess testicular position and closure. Return the testis to an appropriate position; fixation is included in several described techniques. Confirm recipient and donor perfusion and close without tension.
  7. Choose urinary drainage. Duration and route follow the underlying repair. The 2–7-day drainage interval in Landau's series is not a universal TVF protocol.[3][11][12]

Orchiopexy does not guarantee prevention of ascent: it was performed in the Ramez trial, yet three TVF patients developed ascent by 12 months. Pedicle length, tissue handling and the remaining cord anatomy still matter.[11]

Evidence for repairing an established fistula​

SourceReported outcomeImportant scope
Landau 2003Fourteen children with previously failed UCF repairs; no recurrence or stricture at mean 44 months.Selected uncontrolled series; no observed testicular complication does not establish zero risk.[3]
Routh 2006Sixteen children with UCF after TIP; no recurrence at mean 18 months.Twelve had previous failed fistula closures; four were undergoing their first fistula repair.[12]
Muruganandham 2010Thirteen patients with large or multiple fistulas received tunneled TVF; no recurrence in the study's follow-up.Technique allocation depended on size/complexity, so the other treatment groups are not comparable controls.[6]
Ochi 2015Thirty-five fistulas in 26 patients; all repaired without recurrence at mean 7.4 years.Coverage used external spermatic fascia or TVF. This is not an exclusively TVF cohort or 35 independent patients.[13]
Aldaqadossi 2020Forty-three of 45 recurrent fistula repairs succeeded initially.Used a free tunica vaginalis graft, not a pedicled flap. The reported clinic schedule is not a measured follow-up duration.[14]

The 2023 UCF-repair review reported 94.3% pooled success for tunica vaginalis; heterogeneity and selection preclude a reliable head-to-head ranking.[1] In Fahmy's 2016 review, fistula-closure recurrence was 5/97 with TVF versus 11/90 with dartos (P = .39). The frequently quoted 6.4% versus 18.6% comparison concerns repeat hypospadias cases, a different group; neither comparison establishes causal superiority for every recurrent UCF.[2]

Prevention during primary hypospadias repair​

Current EAU pediatric guidance notes that tunica vaginalis may yield better results than dartos and recommends double coverage if dartos is used. Redo reconstruction is individualized. These statements should not be converted into one obligatory flap hierarchy across primary distal, proximal, recurrent and adult fistula surgery.[20]

In the 2025 Ramez trial, 88 children were randomized and 84 analyzed after losses to follow-up. Fistulas occurred in 2/41 TVF versus 9/43 dartos repairs (P = .029). Median operative time was 145 versus 100 minutes. Three TVF patients developed testicular ascent and one penile torque; those small counts are not universal rates. Dartos was dorsal or ventral according to the surgeon, so this was not specifically a double-dartos comparison.[11]

The trial's total HOSE score favored TVF, but HOSE includes fistula status; it is not an isolated measure of appearance. Total PPPS did not differ significantly. Small sample size, one center and limited follow-up temper the findings.[11]

The 2025 Pezzoli review found heterogeneous results in primary distal/midpenile TIP and could not perform a reliable comprehensive meta-analysis. Earlier Tam data combined 38 de-epithelialized preputial flaps with 14 TVFs in the modified group, while Amukele combined dartos and TVF coverage. Their favorable group outcomes cannot be assigned to TVF alone.[7][15][16]

Substitution urethroplasty: limited and configuration-dependent evidence​

Histological epithelial coverage after tunica-based reconstruction is not proof of a clinically superior tissue substitute. Zargooshi's 20-adult hypospadias series used several onlay/tube combinations; 13 underwent biopsy showing stratified epithelial lining. Three patients developed urethral narrowing, with associated meatal problems in two, and required subsequent treatment.[4]

Results have not been uniform: Joseph and Pérez reported narrowing in three of five evaluable patients in each of two onlay configurations. Liu's 2024 technical report describes pedicled tunica onlay for lichen-sclerosus strictures, but does not establish superiority or equivalence to oral mucosa. Such reports should not be treated as a routine alternative pathway for every long stricture.[10][19]

In Theodorescu's rabbit experiment, eight tubular replacements contracted while 16 onlay animals available for long-term assessment had patent urethras. This supports a concern about configuration in that model, not a universal human “never tube” rule.[5] More directly relevant to staging, Harper's six highly reoperative patients developed substantial fibrosis when tunica was exposed as the dorsal component of a staged urethroplasty. An exposed tunica stage should not be adopted routinely from evidence about covered interposition.[17]

Corporal patching for curvature​

Tunica flap or free graft has also been used to cover ventral corporal lengthening. In Braga's retrospective series, recurrent curvature occurred in one of 23 patients receiving a tunica flap alone; many children had not reached adulthood. Hayashi reported parental observations of straight erections in 15 boys, with operative reassessment in only seven. Neither study proves superiority of vascularized flaps over all free grafts.[8][9]

Ritchey reported one recurrent curvature among 19 free-tunica-graft recipients, with follow-up of 1–5 years. This is a different operation and outcome from UCF closure. Assess the degree and source of curvature and plan follow-up through growth; a fixed 45-degree threshold from one series is not the sole indication for corporal grafting.[18][20]

Counseling and follow-up​

Discuss recurrent fistula, urethral or meatal narrowing, penile tethering or torque, testicular ascent, scrotal hematoma, infection and possible injury to donor structures. Absence of a rare event in a small series is not proof that it cannot occur. Fixation, pedicle planning and atraumatic dissection reduce avoidable problems but do not eliminate risk.[3][11]

Follow both the urinary repair and donor site. Evaluate recurrent leakage, a weak stream, penile deviation and altered testicular position. Urinary drainage, activity restrictions and timing of repeat repair should follow tissue recovery and the full reconstruction rather than a single mandatory interval drawn from one series.[3][13][14]

References​

1. 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

2. 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

3. 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

4. Zargooshi J. "Tube-onlay-tube tunica vaginalis flap for proximal primary and reoperative adult hypospadias." J Urol. 2004;171(1):224–228. doi:10.1097/01.ju.0000101881.80100.ab

5. Theodorescu D, Balcom A, Smith CR, et al. "Urethral replacement with vascularized tunica vaginalis: defining the optimal form of use." J Urol. 1998;159(5):1708–1711. doi:10.1097/00005392-199805000-00098

6. 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

7. Pezzoli M, Lo Re M, Carletti V, Masieri L, Mantovani A. "Impact of second-layer coverages on complication rates in primary tubularized incised plate urethroplasty (TIPU) for distal and midpenile hypospadias repair: a systematic review." Pediatr Surg Int. 2025;41(1):240. doi:10.1007/s00383-025-06134-3

8. Braga LH, Pippi Salle JL, Dave S, et al. "Outcome analysis of severe chordee correction using tunica vaginalis as a flap in boys with proximal hypospadias." J Urol. 2007;178(4 Pt 2):1693–1697. doi:10.1016/j.juro.2007.03.166

9. Hayashi Y, Kojima Y, Mizuno K, et al. "Demonstration of postoperative effectiveness in ventral lengthening using a tunica vaginalis flap for severe penile curvature with hypospadias." Urology. 2010;76(1):101–106. doi:10.1016/j.urology.2009.08.080

10. Liu J, Wang M, Wang W. "Urethroplasty with pedicled tunica vaginalis for the treatment of long-segment anterior urethral stricture caused by lichen sclerosus of glans penis." J Vis Exp. 2024;(212). doi:10.3791/66709

11. 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

12. 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

13. 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

14. Aldaqadossi HA, Eladawy M, Shaker H, Kotb Y, Azazy S. "Tunica vaginalis graft for recurrent urethrocutaneous fistula repair after hypospadias surgery." Int J Urol. 2020;27(9):726–730. doi:10.1111/iju.14287

15. Tam YH, Pang KK, Wong YS, et al. "Improved outcomes after technical modifications in tubularized incised plate urethroplasty for mid-shaft and proximal hypospadias." Pediatr Surg Int. 2016;32(11):1087–1092. doi:10.1007/s00383-016-3954-6

16. Amukele SA, Weiser AC, Stock JA, Hanna MK. "Results of 265 consecutive proximal hypospadias repairs using the Thiersch-Duplay principle." J Urol. 2004;172(6 Pt 1):2382–2383. doi:10.1097/01.ju.0000143880.13698.ca

17. Harper L, Michel JL, Sauvat F. "Preliminary experience using a tunica vaginalis flap as the dorsal component of Bracka's urethroplasty." BJU Int. 2017;119(3):470–473. doi:10.1111/bju.13604

18. Ritchey ML, Ribbeck M. "Successful use of tunica vaginalis grafts for treatment of severe penile chordee in children." J Urol. 2003;170(4 Pt 2):1574–1576. doi:10.1097/01.ju.0000083694.44384.39

19. Joseph DB, Pérez LM. "Tunica vaginalis onlay urethroplasty as a salvage repair." J Urol. 1999;162(3 Pt 2):1146–1147. doi:10.1016/S0022-5347(01)68103-5

20. European Association of Urology. EAU Guidelines on Paediatric Urology: Hypospadias. 2026. Guideline.