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Bipedicled Anterior Scrotal Flap (Fakin Technique)

The bipedicled anterior scrotal flap is an axial-pattern flap based on the bilateral anterior scrotal arteries (terminal branches of the external pudendal system) that provides well-vascularized, thin, elastic, predominantly non-hair-bearing coverage for circumferential penile shaft defects. The largest series (Fakin, n = 43 siliconoma patients) reported 100% flap survival, only minor complications, and mean satisfaction 4.37 / 5.[1]

See also: Penile Reconstruction, Penile Skin Grafting (the graft alternative).

Vascular Anatomy​

A microvascular cadaveric study identified three scrotal cutaneous vascular territories widely inter-anastomosed:[2]

  • Two lateral territories — each supplied by an inferior external pudendal artery (femoral branch), entering at the midpoint of the scrotal root and fanning over the corresponding hemiscrotum
  • One central territory — supplied by perineal arteries (internal pudendal system) accessing via the posterior scrotum, running deeply alongside the scrotal septum

Mean internal diameters: deep external pudendal 0.60 mm, superficial perineal 0.50 mm, funicular 0.37 mm.[3]

The bipedicled anterior scrotal flap is based on the bilateral anterior scrotal arteries (terminal branches of the external pudendal arteries) — dual pedicles make it exceptionally reliable. See EPAP perforator anatomy and dissection — used in the sensate variant.

Indications​

IndicationNotes
Foreign-body granuloma (silicone / paraffinoma)Largest published cohort (Fakin n = 43) — the prototype indication[1]
Adult-acquired buried penis27.2% of one mixed cohort[4]
Fournier's gangreneAfter radical debridement when wound bed is non-graftable[5][6]
Circumcision complicationsComplete penile skin loss[5]
Penile cancerAfter wide local excision[7]
Genital lymphedemaAfter radical excision[6]
TraumaAnimal bites, avulsion injuries[7]

Surgical Technique​

Single-stage bipedicled flap (Fakin)[1]​

  1. Degloving and excision — circumferential coronal-sulcus incision; radical excision of all diseased tissue (siliconoma, granuloma, LS) down to Buck's fascia; complete circumferential degloving
  2. Flap design — rectangular or trapezoidal flap centered on the anterior scrotum; flap width = penile-shaft circumference; flap length from penoscrotal junction toward scrotal raphe; both lateral pedicles preserved
  3. Flap elevation — raise above the external spermatic fascia, off dartos / tunica vaginalis; testes temporarily exposed but covered by tunica vaginalis; preserve bilateral anterior-scrotal-artery pedicles at the lateral scrotal roots
  4. Penile tunneling — the denuded shaft is passed through a central window in the elevated flap
  5. Inset — proximal flap edge circumferentially sutured to the coronal sulcus; distal edge to the penile base / pubic skin
  6. Donor closure — primary closure of scrotal donor site by advancing the remaining scrotal skin medially; testes re-covered by posterior / lateral scrotal skin

Mean OR time 2.53 ± 0.46 h.

Two-stage bipedicled flap (Pribaz / McLaughlin)[8]​

Preferred for contaminated beds, concern about flap viability, or very large defects.

  • Stage 1 — bury the denuded shaft into the anterior scrotum; close scrotal skin over the penis ("buried-penis" configuration); leave buried 3–6 weeks to allow neovascularization
  • Stage 2 — incise scrotal skin circumferentially to "unbury"; divide adherent flap from remaining scrotum; inset at coronal sulcus and penile base; close donor site primarily

McLaughlin n = 8 — all satisfactory, only 2 minor complications.

Modified bilateral "butterfly" flap (Yao)[9]​

Single-stage variant using two symmetric flaps on either side of the median raphe, each pedicled on its own anterior scrotal artery. Flaps rotated and wrapped around the shaft from both sides, meeting at dorsal and ventral midlines. Yao n = 7 — satisfactory; 2 small areas of necrosis managed conservatively.

Sensate EPAP hemi-scrotal flap (Tsukuura)​

Perforator-based refinement isolating a single external pudendal artery perforator + the anterior scrotal nerve to create a sensate hemi-scrotal flap.[10] Advantages: uses only one hemiscrotum, wider arc of rotation, documented sensory recovery, tunica vaginalis freed from the pedicle (reduces stretching pain on erection), inconspicuous lateral donor scar.

Single-Stage vs Two-Stage Comparative Data​

Lumbiganon direct comparison in penile foreign-body granuloma (n = 42):[11]

OutcomeSingle-stage (n = 23)Two-stage (n = 12)
Wound infection8.7%0%
Wound dehiscence21.7%8.3%
Reoperation rate26.1%8.3%
Postoperative fever56.5%8.3% (p significant)
No Clavien complications43.5%83.3% (p significant)
Total hospital stay7.4 ± 3.2 d10.9 ± 1.6 d

Two-stage has fewer complications but a longer total LOS.

Outcomes​

Single-stage series (Fakin, n = 43 siliconomas)[1]​

  • Mean OR 2.53 ± 0.46 h
  • Partial flap necrosis 9%, donor-site hematoma 12%, partial wound disruption 19%
  • 100% reported postoperative erection and ability to achieve intercourse
  • Mean patient satisfaction 4.37 / 5

Bilateral pedicled scrotal flap series (Mendel, n = 22)[4]​

  • Early — dehiscence 31.8%, infection 13.6%, hematoma 4.6%; early revision 9.1%
  • Late — skin retraction 27.3%, testicular ascension 22.7%, penile shortening 13.6%, pyramidal shape 4.6%; late revision 27.3%
  • Median EHS 3.5 / 4, POSAS scar score 11.5 / 60, global satisfaction 8 / 10

Long-term series (Zhao, n = 18, mean f/u 2.3 y)[7]​

  • 6 bilateral anterior scrotal artery flaps, 12 total anterior scrotal flaps
  • Penile length significantly increased in both flaccid and erect states
  • Normal erectile function and intercourse ability maintained; no 10-year complications

Advantages vs Skin Grafting​

  • Intrinsic axial blood supply — survives in contaminated / poorly vascularized beds where grafts fail
  • Comparable skin quality — scrotal anterior skin is thin, elastic, predominantly hairless
  • Less contracture than STSG / FTSG — preserves penile length, reduces curvature risk
  • Preserved sensation (ilioinguinal / genitofemoral nerves; deep and superficial)[7]
  • No distant donor site — donor and recipient in the same operative field; primary closure
  • Single-stage option — avoids bolster, immobilization, and graft-take uncertainty of STSG / FTSG

Disadvantages​

  • Hair-bearing potential — posterior scrotal skin may be hair-bearing; anterior generally not, but variable[4]
  • Testicular ascension — ~ 22.7% from scrotal-skin shortage post-harvest[4]
  • Pyramidal penile shape — wider base than tip (~ 4.6%)
  • Late skin retraction — ~ 27.3%, may require revision
  • Penile shortening — ~ 13.6%, possibly from pedicle tethering
  • Some cases require two-stage — though the single-stage Fakin technique has largely supplanted historical staged approaches

Patient Selection​

Best suited for:[1][4][11]

  • Circumferential penile shaft defects too large for primary closure
  • Adequate scrotal skin — prior scrotal surgery, scrotal lymphedema, or scrotal skin disease may preclude
  • Clean or minimally contaminated bed for single-stage; contaminated bed favors two-stage
  • Patient preference to avoid a thigh STSG donor site
  • Length-preservation priority where graft contracture would be unacceptable

Key Takeaways​

  • The dual anterior-scrotal-artery pedicle makes this one of the most reliable axial flaps in genital reconstruction
  • Single-stage Fakin is the modern default for circumferential shaft defects in clean fields; two-stage for contaminated beds and large defects
  • Yao butterfly variant offers single-stage coverage with bilateral midline flaps; EPAP hemi-scrotal offers sensate single-hemiscrotum coverage
  • Late revision rates 9–27% — counsel patients on testicular ascension, pyramidal shape, and skin retraction
  • Preferable to STSG / FTSG when the wound bed is contaminated, the patient is highly sexually active, or graft contracture would be unacceptable

Cross-references​

References​

1. Fakin R, Zimmermann S, Jindarak S, et al. "Reconstruction of Penile Shaft Defects Following Silicone Injection by Bipedicled Anterior Scrotal Flap." J Urol. 2017;197(4):1166–1170. doi:10.1016/j.juro.2016.11.093

2. Carrera A, Gil-Vernet A, Forcada P, et al. "Arteries of the Scrotum: A Microvascular Study and Its Application to Urethral Reconstruction With Scrotal Flaps." BJU Int. 2009;103(6):820–4. doi:10.1111/j.1464-410X.2008.08167.x

3. Giraldo F, Mora MJ, Solano A, González C, Smith-Fernández V. "Male Perineogenital Anatomy and Clinical Applications in Genital Reconstructions and Male-to-Female Sex Reassignment Surgery." Plast Reconstr Surg. 2002;109(4):1301–10. doi:10.1097/00006534-200204010-00014

4. Mendel L, Neuville P, Allepot K, et al. "Bilateral Pedicled Scrotal Flaps as an Alternative to Skin Graft in Penile Shaft Defects Repair." Urology. 2023;176:206–212. doi:10.1016/j.urology.2023.03.025

5. Gao QG, Qu W. "Penile Resurfacing Using a Reverse Bilateral Anterior Scrotal Artery Flap: A Case Report of Penile Skin Defects Following Circumcision." Medicine. 2019;98(49):e18106. doi:10.1097/MD.0000000000018106

6. Kristinsson S, Johnson M, Ralph D. "Review of Penile Reconstructive Techniques." Int J Impot Res. 2021;33(3):243–250. doi:10.1038/s41443-020-0246-4

7. Zhao YQ, Zhang J, Yu MS, Long DC. "Functional Restoration of Penis With Partial Defect by Scrotal Skin Flap." J Urol. 2009;182(5):2358–61. doi:10.1016/j.juro.2009.07.048

8. McLaughlin MM, Abbassi B, Pribaz JJ. "Bipedicled Scrotal Flap for Penile Resurfacing." Plast Reconstr Surg. 2024;153(4):935–942. doi:10.1097/PRS.0000000000010811

9. Yao H, Zheng D, Xie M, et al. "A Modified Bilateral Scrotal Flap for Penile Skin Defect Repair." J Vis Exp. 2022;(189). doi:10.3791/64017

10. Tsukuura R, Engmann T, Miyazaki T, Yamamoto T. "The Sensate External Pudendal Artery Perforator (EPAP) Hemi-Scrotal Flap for the Circumferential Skin Defect of the Penile Shaft." Microsurgery. 2025;45(7):e70123. doi:10.1002/micr.70123

11. Lumbiganon S, Pachirat K, Sirithanaphol W, et al. "Surgical Treatment of Penile Foreign Body Granuloma: Penile Shaft Reconstruction With Single- Versus Two-Stage Scrotal Flap Techniques." Int J Urol. 2023;30(8):681–687. doi:10.1111/iju.15209