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Anterior Obturator Artery Perforator (aOAP) Flap — Vulvovestibular Reconstruction

The aOAP flap is a fasciocutaneous perforator flap developed by Dan mon O'Dey (Aachen / Luisenhospital, Germany) for vulvovestibular reconstruction. Originally described in 2010 based on cadaveric vascular anatomy, it has been applied to two major clinical indications: female genital mutilation/cutting (FGM/C) reconstruction and refractory lichen sclerosus et atrophicus (LSA) with sexual dysfunction as a last-resort surgical option.[1][2][3]

For the broader treatment menu see the Vulvar Reconstruction Atlas. The aOAP shares its vascular territory with the genitocrural island perforator flap (GCIPF) used for oncologic reconstruction — see GCIPF (Vulvar). For the FGM/C complement technique see Foldès Clitoral Reconstruction; for the alternative coverage technique see Mañero Vaginal Mucosal Graft.

Vascular Anatomy​

O'Dey, Bozkurt & Pallua 2010 — 20 specimens from 10 female cadavers:[1]

ParameterDetail
Source vesselAnterior branch of the obturator artery (and accompanying vein), exits the pelvis through the obturator foramen
Perforator type80% musculocutaneous (pierces the gracilis muscle); 20% septocutaneous (passes along the posterior border of the gracilis)
Perforator location1.3 ± 0.3 cm lateral to the inferior pubic ramus
Skin territory~7 × 15 cm, centered on the sulcus genitofemoralis (genitocrural fold)
Tissue characteristicsThin, pliable, hairless — closely matches native vulvar / vestibular tissue in texture, color, and thickness[1]

Consistent with the four constant perineal perforator arteries identified by Jin et al., with rich vascular anastomoses in the deep fascia above the adductor compartment.[4]

Key Advantages​

AdvantageDetail
Thin and pliable tissueClosely mimics native vulvar / vestibular skin — avoids the excessive bulk of musculocutaneous flaps (gracilis, VRAM) that can impair sexual function and cosmesis[1][2]
Proximity to defectDonor site (genitocrural sulcus) is immediately adjacent to the vulva — minimal arc of rotation; tunneled-island design[1]
Concealed donor siteScar hidden within the natural genitocrural fold; preserves self-image[1]
Primary donor closureDonor site closed primarily in most cases[1]
Constant vascular anatomyaOAP perforator present in 100% of cadaveric specimens; predictable location relative to the inferior pubic ramus[1]

Surgical Technique​

  1. Preoperative planning — handheld Doppler identifies the perforator ~1.3 cm lateral to the inferior pubic ramus along the genitocrural sulcus. Flap designed as an elliptical island centered on the perforator, oriented along the sulcus genitofemoralis.[1]
  2. Flap dimensions — skin paddle up to ~7 × 15 cm, tailored to the defect; bilateral flaps are typical for vulvovestibular reconstruction.[1][3]
  3. Flap elevation — raised as a fasciocutaneous island. Dissection from periphery toward the perforator. If musculocutaneous (80%), a small cuff of gracilis muscle is included around the pedicle to protect it; if septocutaneous (20%), perforator dissected along the intermuscular septum.[1]
  4. Tunneled transfer — flap transferred to the vulvar / vestibular defect through a subcutaneous tunnel, preserving the pedicle without skeletonization. This tunneled-island design distinguishes the aOAP from simple transposition flaps.[1]
  5. Inset and closure — flap inset with fine absorbable sutures; donor site closed primarily.[1]

Clinical Application 1 — FGM/C Reconstruction (O'Dey 2024, n = 119)[2]​

In O'Dey's 2014–2021 FGM/C cohort, the aOAP flap was used in 36% of patients (~ 43 women) for vulvovestibular reconstruction — specifically the labia minora, vestibule, and / or vaginal introitus in women with extensive tissue loss from FGM/C (particularly Types II and III).

Three-technique reconstructive system​

TechniquePurposeFrequency
Omega Domed (OD) FlapPreputial (clitoral hood) reconstruction85%
NMCS Procedure (Neurotizing and Molding of Clitoral Stump)Clitoral reconstruction82%
aOAP FlapVulvovestibular reconstruction (labia minora, vestibule)36%

Outcomes (combined techniques, n = 119)[2]​

  • Significant postoperative improvement in clitoral sensation and ability to achieve orgasm (p < 0.05).
  • Significant reduction in dysmenorrhea, dysuria, and dyspareunia (p < 0.05).

Clinical Application 2 — Skinning Vulvectomy + aOAP Flap for Refractory LSA​

O'Dey 2024 (n = 61, 2014–2022) — the most extensive surgical option in the LS ladder, explicitly framed as last-resort.[3] See the perineoplasty + de-adhesion page for the rest of the LS surgical ladder.

Indications and patient selection​

  • Severe diffuse vulvovestibular LS with extensive architectural distortion — beyond what perineoplasty or simple adhesiolysis can address.[3]
  • Disabling dyspareunia or complete apareunia refractory to maximal medical therapy (ultrapotent TCS, topical calcineurin inhibitors, intralesional steroids).[3][6]
  • Failure of or insufficient response to simpler surgery (Fenton's, perineoplasty + de-adhesion, laser adhesiolysis, local skin flaps).[5]
  • Stated patient desire to regain sexual function.
  • Histologically confirmed LS — biopsy mandatory preoperatively to exclude VIN / SCC (0–9% malignant-transformation risk).[8][6]

Operative steps​

The procedure is performed under general anesthesia in three components:[1][3][2]

  1. Skinning vulvectomy. En-bloc excision of all affected vulvovestibular skin in a superficial plane — epidermis and superficial dermis only — preserving subcutaneous fat, muscles, nerves, and deeper vasculature. This is the defining distinction from simple or radical vulvectomy (which extend to the urogenital diaphragm); skinning removes only the disease-bearing tissue layers.[9] All excised tissue is sent for histopathology.[8]
  2. Bilateral aOAP flap harvest and inset. Perforator localized by handheld Doppler at the genitocrural sulcus; fasciocutaneous island flap raised on each side; tunneled island transfer into the vulvar defect for tension-free inset. Bilateral flaps used in 53/61 (87%) of the O'Dey LS series.[3]
  3. Adjunctive procedures as indicated.
    • Omega Domed (OD) flap — preputial / clitoral-hood reconstruction (85% in the FGM/C series, with significant improvement in clitoral sensation and orgasm).[2]
    • Clitoral re-exposure — sharp unroofing of the buried glans from scarred preputium.
    • Scar surgery for additional fibrotic tissue not addressed by the vulvectomy.

Outcomes (O'Dey 2024)​

ParameterResult
n61
Bilateral aOAP flaps53/61 (87%)
Period2014–2022
Follow-up1 yr
Dyspareunia reductionSignificant (p < 0.001)
Inability to have intercourseSignificant reduction (p < 0.001)
ComplicationsSeveral minor, reversible; subset required secondary intervention

LSA-specific complication framing​

Two factors elevate the complication risk above non-LS vulvar reconstructions:[3][10]

  • Tissue fragility from chronic ultrapotent TCS use (epidermal atrophy, impaired wound healing).
  • Altered tissue quality intrinsic to LS biology, complicating flap inset.

Across the combined O'Dey LS + FGM/C cohort (180 patients), total flap loss was reported in only 1 case, and minor wound problems (dehiscence, local infection) dominated — consistent with the 21–33% overall complication rates reported across vulvar flap reconstructions.[11][12] Secondary revision was required in ~8.4% of the FGM/C series.[2]

LSA recurrence — the durability caveat​

The chronic relapsing biology of LS is unmodified by surgery. Historical vulvectomy series for LS reported recurrence rates as high as 50%, and Rangatchew's local-flap series showed 38% severe relapse with apareunia at mean 8.4 yr — recurrence rates which the 1-yr O'Dey aOAP follow-up cannot yet address.[5][8] Indefinite topical maintenance and SCC surveillance remain mandatory.

Perioperative Management (LS-Specific)​

  • Preoperative: maximize topical-steroid disease control; confirm LS histologically; exclude VIN / SCC; counsel on chronic relapsing biology and realistic expectations.[6][8]
  • Intraoperative: handheld-Doppler perforator localization; meticulous hemostasis (TCS-induced tissue fragility); all excised tissue to pathology.
  • Postoperative:
    • Resume topical clobetasol — discontinuation directly linked to LS reactivation with bullae formation.[10]
    • Perineal-zone wound care with attention to urinary / fecal contamination.
    • Vaginal dilators considered to maintain introital patency.
    • Indefinite follow-up for LS recurrence and malignancy surveillance.[6]

Skinning Vulvectomy — Historical Context​

Skinning vulvectomy was originally developed for vulvar intraepithelial neoplasia (VIN), then adapted to LS.[8][9][13]

  • Removes all vulvar skin while preserving subcutaneous tissue and deeper structures — significantly less morbid than simple or radical vulvectomy.[9]
  • Historically combined with split-thickness skin grafting (STSG) — better sexual function and cosmetic results than simple vulvectomy without coverage.[8]
  • Both skinning and simple vulvectomies for LS carry historical recurrence rates as high as 50%, restricting indication to patients who have failed multiple medical and simpler surgical interventions.[8]
  • The O'Dey innovation is replacing the STSG with a vascularized fasciocutaneous flap — superior tissue quality, durability, and sensory potential compared to a graft.[1]

Comparison with Other Vulvar Reconstruction Flaps​

FlapTypeTissue qualityBulkDonor scarMuscle sacrificeKey advantageKey limitation
aOAPFasciocutaneous perforatorThin, pliable, hairlessMinimalConcealed (genitocrural fold)None (or minimal gracilis cuff)Best tissue match for vulva; concealed scarSingle-surgeon experience; limited published data
Lotus petal / pudendal-thighFasciocutaneous axialThin, pliableLow-moderatePerineal / gluteal foldNoneRetains sensory innervation; versatileLimited skin territory for large defects
PAP / DFAPFasciocutaneous perforatorModerate thicknessLow-moderatePosterior medial thighNoneLarge skin paddle; reliable anatomyHigher wound complication rate (37.5%) vs IPAP (12.9%)
GracilisMusculocutaneousModerate-thickModerate-highMedial thighGracilis muscleReliable; fills dead spaceExcessive bulk; functional muscle loss
VRAMMusculocutaneousThickHighAbdominal wallRectus abdominisLarge volume; fills pelvic dead spaceHighest donor-site morbidity (57.6%); abdominal-wall weakness

The Wendelspiess 2024 SR / meta-analysis of perforator vs non-perforator flaps for vulvoperineal reconstruction (49 studies, n = 1,840) found a tendency toward fewer complications with perforator flaps — though the difference did not reach statistical significance; long-term outcomes and QOL assessment were sparse.[7]

Limitations and Considerations​

LimitationDetail
Single-surgeon experienceAll published aOAP data originate from O'Dey's center (Luisenhospital Aachen, Germany); no independent or multicenter replication[1][2][3]
No comparative trialsNo head-to-head comparisons with other perforator flaps (IPAP, PAP) or with the lotus-petal flap
Perforator variabilityaOAP present in 100% of cadaveric specimens, but 20% are septocutaneous rather than musculocutaneous — affects elevation technique[1]
Learning curvePerforator-flap dissection requires microsurgical expertise and familiarity with obturator vascular anatomy
LSA recurrenceChronic relapsing nature of LSA means long-term durability of reconstruction is uncertain[5]
Combined techniqueIn FGM/C, aOAP was always used in combination with OD and / or NMCS — difficult to isolate the specific contribution of the aOAP to overall outcomes[2]

Key Takeaways​

  1. The aOAP flap is a fasciocutaneous perforator flap (anterior branch of the obturator artery) developed by O'Dey for vulvovestibular reconstruction.[1]
  2. Two major clinical indications — FGM/C (vulvovestibular reconstruction in 36% of O'Dey's n = 119 cohort) and refractory LSA (87% of n = 61 received bilateral aOAP after skinning vulvectomy).[2][3]
  3. Vascular anatomy — perforator present in 100% of cadaveric specimens, located 1.3 ± 0.3 cm lateral to the inferior pubic ramus, supplying a ~7 × 15 cm skin territory centered on the sulcus genitofemoralis.[1]
  4. Key advantages — tissue match (thin, pliable, hairless), concealed donor scar, tunneled-island design, primary donor closure.[1]
  5. Evidence base limited to a single surgeon's experience — no independent multicenter or comparative validation.[1][2][3]
  6. The aOAP vascular territory overlaps with the GCIPF used for oncologic vulvar reconstruction (Toulouse algorithm) — same flap, different clinical contexts.

References​

1. O'Dey DM, Bozkurt A, Pallua N. The anterior obturator artery perforator (aOAP) flap: surgical anatomy and application of a method for vulvar reconstruction. Gynecol Oncol. 2010;119(3):526–530. doi:10.1016/j.ygyno.2010.08.033

2. O'Dey DM, Kameh Khosh M, Boersch N. Anatomical reconstruction following female genital mutilation/cutting. Plast Reconstr Surg. 2024;154(2):426–438. doi:10.1097/PRS.0000000000011026

3. O'Dey DM, Rosendahl M, Mordehay D, Kameh Khosh M. Anterior obturator artery perforator (aOAP) flap: a last-resort treatment option for sexual dysfunction in lichen sclerosus et atrophicus. J Plast Reconstr Aesthet Surg. 2024;95:331–339. doi:10.1016/j.bjps.2024.05.046

4. Jin B, Hasi W, Yang C, Song J. A microdissection study of perforating vessels in the perineum: implication in designing perforator flaps. Ann Plast Surg. 2009;63(6):665–669. doi:10.1097/SAP.0b013e3181999de3

5. Rangatchew F, Knudsen J, Thomsen MV, Drzewiecki KT. Surgical treatment of disabling conditions caused by anogenital lichen sclerosus in women: an account of surgical procedures and results, including patient satisfaction, benefits, and improvements in health-related quality of life. J Plast Reconstr Aesthet Surg. 2017;70(4):501–508. doi:10.1016/j.bjps.2016.12.008

6. Lauber F, Vaz I, Krebs J, Günthert AR. Outcome of perineoplasty and de-adhesion in patients with vulvar lichen sclerosus and sexual disorders. Eur J Obstet Gynecol Reprod Biol. 2021;258:38–42. doi:10.1016/j.ejogrb.2020.12.030

7. Wendelspiess S, Kouba L, Stoffel J, et al. Perforator versus non-perforator flap-based vulvoperineal reconstruction — a systematic review and meta-analysis. Cancers. 2024;16(12):2213. doi:10.3390/cancers16122213

8. Abramov Y, Elchalal U, Abramov D, Goldfarb A, Schenker JG. Surgical treatment of vulvar lichen sclerosus: a review. Obstet Gynecol Surv. 1996;51(3):193–199. doi:10.1097/00006254-199603000-00023

9. Lavoué V, Lemarrec A, Bertheuil N, et al. Quality of life and female sexual function after skinning vulvectomy with split-thickness skin graft in women with vulvar intraepithelial neoplasia or vulvar Paget disease. Eur J Surg Oncol. 2013;39(12):1444–1450. doi:10.1016/j.ejso.2013.09.014

10. Burger MP, Obdeijn MC. Complications after surgery for the relief of dyspareunia in women with lichen sclerosus: a case series. Acta Obstet Gynecol Scand. 2016;95(4):467–472. doi:10.1111/aogs.12852

11. Kwong FL, Pounds R, Farah Y, Yap JKW. Vulval flap reconstruction in women with benign, preneoplastic and malignant vulval conditions: a prospective study. BJOG. 2025;132(8):1156–1165. doi:10.1111/1471-0528.18156

12. Commenge V, Martinez A, Ricotta G, et al. Use of the genito-crural island perforator flap in vulvar reconstruction: a single-center experience. Int J Gynecol Cancer. 2025;36(2):102847. doi:10.1016/j.ijgc.2025.102847

13. Lawrie TA, Nordin A, Chakrabarti M, et al. Medical and surgical interventions for the treatment of usual-type vulval intraepithelial neoplasia. Cochrane Database Syst Rev. 2016;(1):CD011837. doi:10.1002/14651858.CD011837.pub2