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Tunica Vaginalis Flap for UCF Repair and Reconstruction

The tunica vaginalis flap (TVF) is the recommended first-choice waterproofing layer for recurrent UCF repair, proximal hypospadias, and repeat hypospadias surgery, achieving a pooled success rate of 94.3% in the 2023 Choudhury meta-analysis (2,886 patients) — second only to scrotal flaps (94.6%).[1][2] First used for UCF repair by Snow and Cartwright in the 1990s, it has become one of the most versatile tissues in reconstructive penile surgery — serving as a waterproofing layer, substitution urethroplasty material, and corporeal graft for chordee correction.[3][4]

For alternative UCF approaches see Simple Closure + Skin Advancement Flap, Double Dartos Flap, PATIO Repair, and Scrotal Flaps; for broader context see the male fistula treatment atlas.

Anatomy and Blood Supply​

The tunica vaginalis is a serous membrane derived from the processus vaginalis (peritoneum). Two layers:

  • Visceral layer — intimately adherent to testis and epididymis; not harvested
  • Parietal layer — lines the inner scrotal wall, separated from scrotal dartos by loose areolar tissue; this is the layer harvested for TVF

Thin, translucent, well-vascularized membrane lined by a single layer of flattened mesothelial cells. Blood supply: cremasteric vessels (cremasteric artery, branch of inferior epigastric), running on the external surface.[5][6] Flap is typically based superiorly (toward the external inguinal ring), maintaining the cremasteric pedicle. This independent blood supply — separate from penile vasculature — is the key advantage over penile dartos flaps in scarred fields.[1][3]

Histological Properties​

Unique biological features that make TVF ideal for urethral reconstruction:

  • Mesothelial → stratified epithelial metaplasia — Zargooshi urethral biopsy after TVF urethroplasty showed stratified epithelium indistinguishable from native urethra in all 13 patients biopsied[4]
  • Experimental confirmation — Theodorescu rabbit model: mesothelial lining of TVF onlay was replaced by stratified epithelium similar to urothelium with 100% urethral patency. Talja: 1/15 stricture (TVF) vs 2/10 (preputial graft). Hua 2019: complete integration and transformation to urinary pseudostratified epithelium by 12 weeks[7][8][9]
  • Elastic and pliable — conforms to urethral contour without bulk or rigidity
  • Non-hair-bearing — unlike scrotal skin, eliminates intraluminal hair-growth risk

Indications​

First-choice indications​

  • Recurrent UCF repair — TVF significantly superior to dartos (Fahmy SR: 6.4% vs 18.6% recurrence, P = 0.020)[2]
  • Proximal hypospadias — single dartos 8.8% fistula rate; TVF preferred[2]
  • Repeat / reoperative hypospadias — TVF provides unscarred tissue when penile dartos is fibrotic[2][3]
  • Large fistulas (> 4 mm) or multiple fistulas — broad, reliable coverage[10]

Secondary indications​

  • Primary distal / midpenile hypospadias — TVF 2.0% (distal) and 0–3.1% (midpenile) UCF rates, though double dartos (0.6%) preferred for distal[2][11]
  • Ventral corporeal lengthening for severe chordee (> 45°)[12][13]
  • Substitution urethroplasty — onlay (tube-onlay-tube) reconstruction[4][14]
  • Urethral stricture repair — alternative to buccal mucosa, especially in lichen sclerosus[14]

Contraindications​

  • Prior ipsilateral orchidopexy or inguinal hernia repair — may compromise cremasteric vascular pedicle[15]
  • Prior orchiectomy — no testis to harvest from
  • Bilateral TVF harvest possible but increases testicular complication risk

Surgical Technique — TVF as Waterproofing Layer (Landau 2003)​

The landmark technique:[3]

  1. Fistula identification — inject povidone-iodine (or methylene blue) via the urethral meatus to identify all tracts; critical to avoid missing occult fistulas
  2. Exclude distal obstruction — urethral calibration or cystoscopy to rule out meatal stenosis or distal stricture (most common cause of UCF repair failure)
  3. Fistula excision and urethral closure — circumscribe, excise, close defect with fine absorbable suture (6-0 or 7-0 polyglactin / polyglycolic acid) in an inverting fashion. In 2/14 Landau patients, the defect was too large for primary closure and required an onlay island flap
  4. Scrotal incision — small transverse incision on the ipsilateral hemiscrotum
  5. Testicular delivery — deliver the ipsilateral testis through the scrotal incision
  6. TVF harvest — incise the parietal layer; raise a rectangular flap maintaining the superior cremasteric pedicle; dissect free from the visceral layer while preserving superior pedicle attachment
  7. Subcutaneous tunneling — create a tunnel from the scrotal incision to the penile-shaft fistula repair site; pass the TVF through
  8. Flap placement — lay over the urethral suture line with the flap extending ≥ 5 mm beyond the suture line in all directions; secure with fine absorbable suture; offset suture lines from the urethral closure
  9. Orchidopexy — return the testis to the scrotum and fix to the scrotal dartos with absorbable sutures to prevent ascent or retraction
  10. Skin closure — close scrotal and penile skin over the TVF
  11. Urinary diversion — urethral stent (± suprapubic catheter) for 2–7 d

Technique Variants​

Tunneled TVF (Routh / Reinberg 2006)​

Emphasizes the subcutaneous tunneling for delivery from scrotum to penile shaft:[16]

  • 16 boys (median age 2.2 yr) with UCF after failed TIP
  • 12/16 had 1–4 prior failed repairs; all had subcoronal fistulas; 8 had additional shaft fistulas (up to 4 per patient)
  • Mean OR time 45 min; 100% success at mean 18-mo follow-up; no complications

Traction-assisted dissection + TVF / external spermatic fascia (Ochi 2015)​

Refined technique combining meticulous fistula dissection with TVF coverage:[17]

  • 35 UCF in 26 patients (12 recurrent, mean 2.5 prior repairs)
  • Superficial circumscribing incision 3–5 mm around fistula; multiple stay sutures for traction; dissect only the epidermis under traction for 7–10 mm to preserve perfusion
  • Pedicled external spermatic fascia or TVF mobilized through subcutaneous tunnel
  • 100% success at mean 7.4 yr (range 0.4–17.3); no testicular complications or scrotal deformity

TVF graft (Aldaqadossi 2020)​

Simplified variant using TVF as a free graft rather than a pedicled flap:[18]

  • 45 children with recurrent UCF
  • TVF harvested and placed as an intermediate protective layer (graft, not pedicle)
  • 95.6% success (43/45); 2 recurrences repaired after 6 mo
  • Mean LOS 5.5 d; satisfactory cosmesis; no torsion or chordee

Outcomes — TVF for UCF Repair​

StudyYearnSettingSuccessFollow-up
Landau200314Recurrent UCF (mean 2.4 prior repairs)100%44 mo (8–60)[3]
Routh200616UCF after failed TIP (1–4 prior)100%18 mo (4–36)[16]
Muruganandham201013Large (> 4 mm) or multiple UCF100%3.5 yr[10]
Ochi201535 UCF (26 pts)Primary + recurrent UCF100%7.4 yr (0.4–17.3)[17]
Aldaqadossi202045Recurrent UCF (graft technique)95.6%Weekly → monthly → annual[18]
Choudhury pooled meta2023PooledAll TVF for UCF repair94.3%Variable[1]

TVF for Primary Hypospadias Repair (Fistula Prevention)​

StudynHypospadias typeComparatorTVF UCFComparator UCFP
Chatterjee 200449Coronal to penoscrotalDartos0% (0/29)15% (3/20)—[19]
Fahmy 2016 pooled244 distalDistalSingle dartos2.0%5.1%—[2]
Tam 201614 TVF vs 52 DDMidshaft / proximalDorsal dartos7.7% (combined w/ DESP)28.8%0.005[20]
Ramez RCT 202588 (41 TVF / 43 DD)Distal / midshaftDartos4.9% (2/41)20.9% (9/43)0.029[15]
Pezzoli 2025 SR40 studiesMidpenileSingle DD0–3.1%12.5–36.4%—[11]
Amukele 2004265ProximalNo flap1.8% (w/ flap)17% (without)—[21]

TVF vs Dartos — The Ramez RCT 2025​

The most rigorous head-to-head — single-center RCT, 88 patients, distal / midshaft TIP repair:[15]

OutcomeDartos (n = 43)TVF (n = 41)P
UCF rate20.9% (9/43)4.9% (2/41)0.029
Meatal stenosis7.0% (3/43)4.9% (2/41)NS
Penile torque0%2.4% (1/41)NS
Testicular ascent (12 mo)0%7.3% (3/41)0.071
Median OR time100 min (90–120)145 min (140–150)0.001
HOSE score (cosmesis)LowerHigher (better)0.024
PPPS score——0.076

TVF significantly reduced UCF (P = 0.029) and achieved better HOSE cosmetic scores (P = 0.024), but at the cost of 45 min longer OR time and a 7.3% testicular ascent rate at 12 mo.[15]

TVF vs All Other Waterproofing Layers​

TechniquePooled UCF-repair successPrimary distal UCFRepeat case UCF
Scrotal flaps94.6%——[1]
Tunica vaginalis flap94.3%2.0%6.4%[1][2]
PATIO93.5%——[1]
Biomaterials92%——[1]
De-epithelialized skin flap95.7%——[1]
Double dartos81%0.6%Limited data[1][2]
Single dartos78.8%5.1%18.6%[1][2]
Simple closure73.2%——[1]

Complications​

Testicular ascent​

The most significant TVF-specific complication. Ramez RCT: 7.3% at 12 mo (3/41); P = 0.071 (not statistically significant, but clinically meaningful).[15] Mechanism: tethering of the testis superiorly by the TVF pedicle, which is based toward the external inguinal ring. Orchidopexy at the time of TVF harvest is recommended to mitigate.[3]

Penile torque​

2.4% (1/41) in Ramez RCT.[15] Occurs because TVF is harvested from one side (unilateral), creating asymmetric ventral tissue bulk.

Hydrocele​

Theoretical risk from disruption of the tunica vaginalis sac. Not reported as a significant complication in the major UCF repair series.

Testicular atrophy / torsion​

Theoretical concerns that have not been observed in any major clinical series. Landau specifically noted "no postoperative complications were encountered in the testicles" at 44 mo.[3] Muruganandham confirmed no testicular or scrotal complications.[10]

Longer operative time​

~ 45 min longer than dartos due to scrotal incision, testicular delivery, harvest, tunneling, and orchidopexy.[15]

Fibrosis when exposed to external environment​

Harper 2017 — TVF used as the dorsal component of a two-stage Bracka urethroplasty (exposed externally between stages): all 6 patients developed significant fibrosis rendering the graft unusable for tubularization at the second stage. TVF should NOT be used as an exposed graft in staged procedures.[22]

Beyond Waterproofing — TVF as Substitution Urethroplasty​

Zargooshi tube-onlay-tube technique (2004)​

20 adults with proximal primary (8) and reoperative (12) hypospadias — TVF used for combined onlay-tube reconstruction. No fistula or diverticulum developed; urethral biopsy showed stratified epithelium indistinguishable from native urethra. Complications (15%) limited to distal urethral strictures in reoperative cases, all managed with internal urethrotomy.[4]

Liu pedicled TVF for long-segment stricture (2024)​

19-year experience, 86 cases of long-segment anterior urethral stricture from lichen sclerosus. TVF as a dorsal onlay patch; mesothelial surface facilitates re-epithelialization. Performed under spinal anesthesia.[14]

Onlay vs tube — Theodorescu rabbit model​

TVF as onlay flap achieved 100% urethral patency; TVF as tube resulted in contracture in all 8 animals — likely from cremasteric muscle elements brought with the tunica. Onlay configuration is strongly preferred.[7]

TVF for Ventral Corporeal Lengthening (Chordee Correction)​

A distinct role in correcting severe ventral curvature (> 45°) associated with proximal hypospadias:

  • Braga 2007 (n = 38 boys with chordee > 45°; TVF alone in 23) — at median 5.3 yr: TVF 95.7% success (1/23 recurrent curvature) vs lyophilized dura grafts 55.6% (4/9 recurrence, P = 0.02). Straight erections in 85.7%.[12]
  • Hayashi 2010 (n = 15 boys with severe curvature) — ventral TVF patching; all achieved straight erections; at second-stage surgery, the TVF-patched area showed no contraction, confirming vascularized-flap superiority over free grafts for corporeal lengthening.[13]
  • Ritchey & Ribbeck 2003 — 19/25 children with severe chordee received TVF free grafts: only 1/19 (5.3%) recurrent chordee — excellent results even with free (non-pedicled) TVF for corporeal patching.[23]

Advantages​

  • Highest-tier UCF-repair success (94.3%) — tied with scrotal flaps[1]
  • Significantly superior to dartos for recurrent UCF — 6.4% vs 18.6% (P = 0.020)[2]
  • Unscarred tissue from outside the penile field — cremasteric blood supply independent of penile vasculature; ideal for multiply-operated patients with fibrotic penile tissue[3][16]
  • Non-hair-bearing — no risk of intraluminal hair growth[4]
  • Mesothelial → urothelial metaplasia — suitable for both waterproofing and substitution urethroplasty[4][7]
  • Versatile — waterproofing, onlay urethroplasty, corporeal chordee graft[4][12]
  • Easy to mobilize — multiple authors describe TVF harvest as "technically simple"[3][16][18]
  • Location-agnostic — Landau 100% across perineal, penoscrotal, midshaft, and subcoronal fistulas[3]
  • Long-term durability — Ochi 100% at mean 7.4 yr (up to 17.3 yr)[17]

Limitations​

  • Testicular ascent — 7.3% at 12 mo in Ramez RCT; orchidopexy mitigates but does not eliminate[15]
  • Longer OR time — ~ 45 min longer than dartos[15]
  • Requires scrotal incision — vs penile dartos / PATIO which need none
  • Contraindicated after prior inguinal surgery — orchidopexy or inguinal hernia repair may compromise the cremasteric pedicle; scrotal dartos flap preferred in these patients[15][24]
  • Not suitable for exposed staged procedures — undergoes fibrosis and retraction (Harper 2017)[22]
  • Tube configuration prone to contracture — use as onlay only; tube fails due to cremasteric muscle elements[7]
  • Penile torque — 2.4% from unilateral harvest[15]
  • Onlay urethroplasty results mixed — Joseph & Pérez reported substantial complication rate (60% meatal stenosis at meatus, 60% stricture proximal to glans) with TVF onlay urethroplasty as salvage, cautioning against use for urethral substitution in certain configurations[25]

Evidence-Based Algorithm — Where TVF Fits​

Based on Fahmy 2016 Eur Urol SR and Choudhury 2023 meta:[1][2]

  1. Primary distal hypospadias → Double dartos (0.6%) > TVF (2.0%)
  2. Primary midpenile hypospadias → TVF (0–3.1%) or double dartos (< 5%)
  3. Primary proximal hypospadias → TVF (Amukele 1.8% w/ flap vs 17% without)
  4. Recurrent UCF repair → TVF first-choice (6.4%) over dartos (18.6%, P = 0.020)
  5. UCF repair when prior inguinal surgery → scrotal dartos preferred over TVF
  6. Severe chordee (> 45°) → TVF corporeal graft — 95.7% success
  7. Hypospadias cripples → TVF for waterproofing; consider TVF onlay for urethral substitution in selected cases

Technical Pearls​

  • Always exclude distal obstruction before UCF repair — inject povidone-iodine or methylene blue via the meatus; calibrate or cystoscope[3]
  • Harvest the parietal layer only — avoid injury to the visceral layer adherent to the testis
  • Maintain the superior pedicle — cremasteric vessels enter superiorly; preserve this attachment during harvest
  • Create an adequate subcutaneous tunnel — wide enough to avoid pedicle compression but narrow enough to prevent dead space
  • Always perform orchidopexy — fix testis to scrotal dartos with absorbable suture to prevent ascent[3][15]
  • Offset all suture lines — urethral, TVF, and skin closures should not overlap
  • Use TVF as onlay, not tube — tube configuration contracts from cremasteric muscle[7]
  • Wait ≥ 6 months after the last surgery before UCF repair to allow tissue maturation[18]
  • Consider contralateral TVF if ipsilateral is insufficient or previously harvested — Zargooshi used contralateral TVF as a blanket wrap in 15 of 20 patients[4]
  • Microscope / loupe magnification — Landau performed all repairs under microscope; likely contributes to outcomes[3]

Key Takeaways​

  • First-choice for recurrent UCF, proximal hypospadias, and repeat hypospadias surgery — Choudhury pooled 94.3%; Fahmy 6.4% recurrent vs dartos 18.6% (P = 0.020).
  • Mesothelial → urothelial metaplasia is the unique biological property enabling TVF use for both waterproofing AND substitution urethroplasty.
  • Onlay only, never tube — Theodorescu rabbit model 100% patency onlay vs 100% contracture tube.
  • Three signature complications — 7.3% testicular ascent (mitigated by orchidopexy), 2.4% penile torque, ~45 min longer OR.
  • Contraindicated after prior inguinal surgery — scrotal dartos preferred.
  • Severe chordee (> 45°) — TVF corporeal graft achieves 95.7% success (Braga) vs 55.6% lyophilized dura.

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. Mostafa T, Labib I, El-Khayat Y, El-Rahman El-Shahat A, Gadallah A. "Human testicular arterial supply: gross anatomy, corrosion cast, and radiologic study." Fertil Steril. 2008;90(6):2226–2230. doi:10.1016/j.fertnstert.2007.10.013

6. Redman JF. "Applied anatomy of the cremasteric muscle and fascia." J Urol. 1996;156(4):1337–1340.

7. 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

8. Talja M, Kivisaari L, Mäkinen J, Lehtonen T. "Free tunica vaginalis patch in urethroplasty. An experimental study." Eur Urol. 1987;13(4):259–263. doi:10.1159/000472791

9. Hua X, Chen J, Xu Y, Li B. "Combined dorsal plus ventral double tunica vaginalis graft urethroplasty: an experimental study in rabbits." Urology. 2019;126:209–216. doi:10.1016/j.urology.2018.10.058

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. Chatterjee US, Mandal MK, Basu S, Das R, Majhi T. "Comparative study of dartos fascia and tunica vaginalis pedicle wrap for the tubularized incised plate in primary hypospadias repair." BJU Int. 2004;94(7):1102–1104. doi:10.1111/j.1464-410X.2004.05111.x

20. 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

21. 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

22. 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

23. 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

24. Churchill BM, van Savage JG, Khoury AE, McLorie GA. "The dartos flap as an adjunct in preventing urethrocutaneous fistulas in repeat hypospadias surgery." J Urol. 1996;156(6):2047–2049.

25. 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