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Anterior Vaginal Wall Mucosal Inlay (Önol)

The anterior vaginal wall mucosal inlay urethroplasty is a ventral augmentation technique for female urethral stricture (FUS) that opens the urethra ventrally and inlays a pedicled strip of anterior vaginal wall mucosa into the urethrotomy to widen the lumen. The technique most closely associated with this terminology is the one described by Önol 2011, who used it in 10 of 17 women undergoing urethroplasty.[1][2][3] A simplified variant was described by Schwender / Gormley 2006.[4]

For the family of related anterior-vaginal-wall techniques, see the Blandy U-Flap and the Lateral-Based Anterior Vaginal Wall Flap (Romero-Maroto / Simonato). For graft alternatives, see Female Dorsal Onlay BMG and Ventral Onlay BMG.

Where the Önol Inlay Sits in the Family​

"Anterior vaginal wall mucosal inlay" is a family of related techniques sharing one principle: ventral urethrotomy with inlay of anterior vaginal wall tissue to augment the urethral lumen. Variants:[2][3][5]

  • Blandy U-flap. Proximally based U-shaped pedicled flap (classic).
  • Lateral-based vaginal flap (Romero-Maroto / Simonato). Laterally pedicled modification.
  • Gormley / Schwender vaginal inlay flap. Simplified ventral inlay approach.[4]
  • Önol 2011 U-shaped inlay. Ten women in a 17-patient mixed-technique series received a ventral U-shaped vaginal-flap inlay in the Blandy/Schwender family; inlay-specific outcomes were not reported separately.[1][21]
  • Borchert vaginal free graft (dorsal onlay). Non-pedicled graft placed dorsally; same tissue source, different placement.[6]

The Önol inlay is distinguished from a dorsal-onlay graft (different urethral surface) and from a tubularized vaginal flap such as the Blaivas neourethra (rolled into a tube rather than inlaid).

Indications​

  • FUS refractory to dilation or DVIU.[1][2]
  • Mid-to-distal urethral strictures. Most common location.[1][7]
  • Healthy, well-estrogenized anterior vaginal wall.[2][8]
  • Önol's series included primary urethroplasty in 10/17 women and argued for it as a first-line option.[1] The EAU 2026 guideline strongly recommends urethroplasty after a second recurrence when intermittent self-dilatation is unsuitable or the patient wants definitive repair.[21]

Contraindications​

  • Lichen sclerosus or vaginal atrophy. Compromised tissue; BMG preferred. Önol used dorsal BMG in 2 patients with atrophic vaginas.[1][2][8]
  • Prior sling-related periurethral scarring may limit a vaginal inlay. Önol used Martius-reinforced ventral BMG in two women with prior synthetic slings.[1]

Önol Technique​

Dorsal lithotomy, regional or general anesthesia.[1]

  1. Preoperative assessment. Integrated anatomical and functional assessment.[1] The original series used detrusor pressure during voiding > 20 cm H₂O alongside caliber and flow criteria.[1] Use voiding cystourethrography or videourodynamics to map stricture location and length; cystourethroscopy can assess the lumen but may not traverse a tight distal narrowing.[1][22]
  2. U-shaped vaginal flap incision. Make an inverted-U incision in the anterior vaginal wall just below the ventral urethral meatus; dissect the flap away from the ventral urethra while preserving its submucosal vascular pedicle.[21][22]
  3. Ventral urethrotomy. When feasible, pass a guidewire into the bladder to help avoid a false passage; make a longitudinal 6 o'clock incision through the full length of the stricture into healthy mucosa proximally and distally.[22]
  4. Vaginal mucosal flap creation. Flap fashioned from anterior vaginal wall adjacent to the urethrotomy. The flap remains pedicled (attached to its submucosal vascular supply), which distinguishes it from a free graft.
  5. Inlay. Suture the tip of the U-flap to the proximal end of the ventral urethrotomy, then secure both flap edges to the urethral mucosal edges with interrupted 4-0 absorbable sutures, orienting vaginal mucosa toward the lumen.[22]
  6. Proximal urethral mucosa adjunct. In one Önol patient, the dilated proximal urethral mucosa was used as an additional tissue source, illustrating the technique's adaptability.[1]
  7. Second-layer closure. Vaginal wall closed as a second layer over the repair.
  8. Catheter. Postoperative urethral catheter.

Technical pearls. Keep the inlay pedicled (preserves blood supply); the ventral approach preserves the dorsal urethral surface and pubourethral ligaments.[2][3][9] Schwender / Gormley specifically emphasized the technique's simplicity and learnability.[4]

Schwender / Gormley Variant (J Urol 2006)​

A closely related simplified ventral inlay:[4]

  • Ventral aspect of the stricture incised longitudinally.
  • Vaginal inlay flap advanced into the urethrotomy defect and sutured to urethral edges.
  • 8 women, 2 institutions, 1–9 yr follow-up.
  • All eight women in the 2006 report had subjective symptom relief; mean caliber rose from 9.25 to 16.5 Fr, mean PVR fell from 130 to 15 mL, and no stress urinary incontinence was reported. One woman underwent repeat dilation 3 weeks after repair without subsequent recurrence.[4]

Expanded, overlapping follow-up. Gormley's 2010 report included 12 women with 3 months to 9 years of follow-up. All reported relief of most symptoms, but urgency and catheterization difficulty persisted in some; one required cystoscopy and catheter insertion in the operating room at 58 months. The EAU 2026 appraisal lists 10/12 as stricture-free.[23][21]

Pedicled Inlay vs Vaginal Free Graft​

FeaturePedicled Vaginal Inlay (Önol / Gormley)Vaginal Free Graft (Borchert)
Blood supplyMaintains own pedicleRelies on recipient bed (imbibition → inosculation)
Tissue viabilityPedicle retains local blood supply; comparative viability is unmeasured[2]Requires an adequate vascular recipient bed[6]
PlacementVentralDorsal (Borchert technique)
Tissue handlingLess manipulation; stays attachedHarvest, prepare, transplant
Vaginal narrowing riskNot quantified for the mobilized pedicled flap[22]Possible with extensive graft harvest[22]
Behavior in scarred bedsPedicle retains blood supply, but outcomes in scarred beds are not established; Önol used BMG with Martius in two prior-sling patients[1]Depends on a suitable recipient bed[6]
Donor-site morbidityVaginal incision and closure; no oral harvestVaginal graft-harvest wound and possible narrowing if harvest is extensive[6]

Borchert 2022 described the free-graft variant: the vaginal mucosa is harvested separately, the underlying fibromuscular tissue is removed, and the thin mucosal graft is placed dorsally after dorsal urethrotomy. Tenets are adequate dorsal dissection, full-length stricture incision, and tension-free anastomosis. Harvest-site selection avoids excessive vaginal narrowing.[6]

Outcomes​

SeriesnTechniqueSuccessFollow-upCaliber / QmaxPVRDe-novo SUI
Önol 2011[1]17 (10 with inlay)Mixed series; anterior vaginal wall mucosa inlay in 10100% objective, 88% subjective (all 17)24 mo (median; range 6–78)Qmax 10.8 → 28.9 mL/s in all 17 patients120 → 30 mL in all 17 patientsnot reported
Schwender / Gormley 2006[4]8Vaginal inlay flap100% subjective1–9 yrcaliber 9.25 → 16.5 Fr130 → 15 mL0%
Hajebrahimi 2019[10]14Tubularized anterior vaginal U-flap with dorsal urethrotomy100% (voiding LUTS improved or cured)—Qmax → 15.8 mL/s→ 27.4 mL2/14 postoperative SUI; new onset not specified
Romero-Maroto 2018[11]9Lateral-based vaginal flap9/9 symptom relief; 0/9 recurrence80.7 mo (mean; range 12–198)Qmax 6.8 → 21 mL/s—0%
Lane 2020 SUFU[12]68 enrolled in local-flap arm (10 without recurrence status)Local-tissue flap (mixed)83% recurrence-free at 12 mo (time-to-event estimate)12 mo median for local-flap arm; 14.6 mo for overall analyzed cohort———

Across nonrandomized series, the reviews report about 92% success for local flaps, 87–90% for grafts, and 41–49% for dilation.[5][13]

Inlay vs Other Urethroplasty Tissue Sources​

TechniqueTissue / approachReported successAdvantageLimitation
Anterior vaginal wall mucosal inlay (pedicled)Anterior vaginal wall, ventralÖnol inlay-specific outcome not reported separately; 17 mixed repairs had 17/17 objective and 15/17 subjective cure at median 24 months[1]; eight Gormley-type inlay patients reported subjective relief[4]Pedicled supply; no oral harvestLocal-tissue quality and vaginal wound; spraying risk for this inlay unquantified
Vaginal free graft (dorsal onlay)Anterior vaginal wall, dorsal[6]64/75 (85.3%) without recurrent stricture across five series at 8.5–24.65 months mean/median follow-up[21]Avoids BMG harvest; dorsal placementRecipient-bed dependent; vaginal narrowing risk
Dorsal onlay BMGBuccal mucosa, dorsal>90% in 25 women (two recurrences at 3 months)[14]Oral donor tissue avoids genital skin; recipient LS can still recurOral donor-site morbidity
Ventral onlay BMGBuccal mucosa, ventral98% stricture-free after onlay (41/42, mean 38.1 mo); separate ventral-inlay cohort: 89.13% success (46 women, median 27.5 mo)[9][15]Preserves sphincter; spongiosal supportOral donor-site morbidity

Kumar 2025 systematically reviewed and meta-analyzed 18 original articles on BMG and vaginal-wall graft urethroplasty, finding no significant difference in reported success (BMG 86.2% versus VWG 89.8%), Qmax, or PVR; its success definition included Qmax >15 mL/s at 3 months, PVR <30 mL, and AUA symptom-score improvement.[16] The AUA 2023 amendment states that surgeons may reconstruct female urethral strictures with oral mucosal grafts, vaginal flaps or a combination .[17] It reports success rates of 69–95% across these techniques and notes that technique selection rests on surgeon experience.[17]

Advantages​

  1. No oral donor-site morbidity. A vaginal donor wound remains; no oral wound, no cheek / lip numbness, no trismus.[1][2]
  2. Pedicled blood supply. The flap keeps its own blood supply, which has been proposed as an advantage over a free graft in compromised beds.[2][3]
  3. Technical simplicity. Schwender / Gormley specifically emphasized this as an advantage given the rarity of FUS and limited surgical experience.[4]
  4. Single operative field. No second team or harvest site.[1]
  5. Tissue compatibility. Vaginal mucosa is wet, hairless, elastic, histologically similar to urethral mucosa.[2]
  6. Primary-urethroplasty option. Önol reported 10 primary repairs and 10 vaginal mucosal inlays among 17 women without specifying their overlap; the authors considered primary urethroplasty a first-line option.[1]

Limitations and Concerns​

  • Tissue-quality dependence. Lichen sclerosus, vaginal atrophy, or prior radiation may compromise local vaginal tissue; assess flap quality and consider an alternative graft when healthy local tissue is unavailable.[2][8]
  • Urinary spraying. Higuchi reported spraying in 2/7 vaginal-flap patients and none of eight dorsal-BMG patients at median 12 months. Higuchi did not specify flap subtype.[7][21] Separately, the EAU evidence table records an inwardly directed stream in two women from Önol's mixed series.[7][21]
  • Retrusive meatus. Classic Blandy variant carries this risk; the lateral-based modification aims to reduce it.[11]
  • Comparative outcomes. Higuchi reported anatomical success in 4/7 vaginal-flap and 7/8 dorsal-BMG patients at median 12 months; Kowalik reported two recurrences among six vaginal-flap patients and none among four dorsal-BMG patients in a ten-woman cohort that included one traumatic urethral-laceration repair.[7][18] A 2025 multicenter cohort reported two-year stricture-free survival of 73% in 17 ventral-flap, 86% in 115 ventral-graft, and 80% in 33 dorsal-graft patients, without a significant group difference.[20] Prior radiotherapy predicted recurrence.[20]
  • Proximal or long strictures. U-shaped vaginal-inlay reports chiefly involve distal-to-mid disease; a lateral vaginal flap or graft may be considered for longer or proximal strictures. Dorsal BMG was used for panurethral disease in Higuchi and Khawaja.[7][14][22]
  • Limited inlay-specific evidence. Schwender reported eight inlays at two institutions, and Önol included ten inlays within 17 mixed repairs without separate subgroup outcomes.[1][4]

Complications​

  • Stricture recurrence. Other vaginal-flap variants had 0/9 recurrences in Romero-Maroto, 2/6 in Kowalik (five U-flaps and one island flap), and 3/7 in Higuchi at different follow-up intervals.[7][11][18]
  • Postoperative SUI. Schwender and Romero-Maroto reported no stress incontinence after repair; Hajebrahimi observed SUI in 2/14 women.[4][10][11] A literature review of surgical interventions for female urethral stricture reported mild to moderate post-surgery de novo incontinence in 9.4% of patients, most of whom recovered with pelvic floor exercises.[5] One patient in the Hajebrahimi series needed a midurethral sling.[10]
  • Urinary spraying. Reported after ventral flap repair.[7]
  • De novo urgency. Reported even with technically successful repairs.[10]
  • Urethrovaginal fistula. Vaginal flaps provide vascularized local tissue; overlapping ventral urethral and vaginal suture lines can pose a fistula risk. Martius interposition has been described for selected poor-tissue ventral free-graft repairs.[2][22]

When to Choose the Önol Inlay​

  • Stricture is distal or mid-urethral.[1][2]
  • Anterior vaginal wall is healthy and well-estrogenized (no LS).[2][8]
  • Surgeon prefers to avoid BMG donor-site morbidity.[1][2]
  • A pedicled flap with own blood supply is preferred over a free graft.[2][3]
  • Prior sling surgery prompts assessment of periurethral scarring and flap mobility; Önol used Martius-reinforced ventral BMG for two such patients.[1]
  • Primary urethroplasty may be considered as a first-line option in Önol’s mixed-technique series.[1]

Postoperative Management​

  • After anterior vaginal-wall flap repair, a technical review describes catheter drainage for 7–10 days and removal when urethrography shows no extravasation.[22]
  • Voiding trial with uroflowmetry and PVR.
  • Cystoscopy at 3–6 mo.
  • Topical estrogen in postmenopausal women.[8]
  • Continue long-term surveillance: Lane's multicenter cohort had a 14.6-month median follow-up, and Blaivas's mixed-technique series documented recurrences at 5.5 and 6 years.[12][24]

Summary​

The Önol anterior vaginal wall mucosal inlay is a technically straightforward ventral augmentation urethroplasty that uses a pedicled strip of anterior vaginal wall mucosa to widen the lumen, with 100% objective cure at 24-month median follow-up across the 17 women in the index mixed series (10 of whom had the inlay) and a 92% local-flap success estimate in an older review; the 2026 EAU synthesis reports 81.4% patency across 161 vaginal-flap repairs, and neither estimate is specific to Önol's inlay.[1][5][21] Its strengths are technical simplicity, no oral donor wound, and a pedicled blood supply. Its limitations include dependence on healthy vaginal tissue and uncertain inlay-specific rates of recurrence and inwardly directed stream.[1][7][21] When vaginal tissue is unsuitable, BMG urethroplasty is an alternative if the recipient bed is appropriate; select the approach by stricture anatomy, tissue quality, and surgeon experience.[1][7][16][19][21]

References​

1. Önol FF, Antar B, Köse O, Erdem MR, Önol ŞY. Techniques and results of urethroplasty for female urethral strictures: our experience with 17 patients. Urology. 2011;77(6):1318-1324. doi:10.1016/j.urology.2011.01.017.

2. Bouchard B, Campeau L. Surgery for female urethral stricture. Neurourol Urodyn. 2025;44(1):51-62. doi:10.1002/nau.25358.

3. Faiena I, Koprowski C, Tunuguntla H. Female urethral reconstruction. J Urol. 2016;195(3):557-567. doi:10.1016/j.juro.2015.07.124.

4. Schwender CE, Ng L, McGuire E, Gormley EA. Technique and results of urethroplasty for female stricture disease. J Urol. 2006;175(3 Pt 1):976-980; discussion 980. doi:10.1016/S0022-5347(05)00336-8.

5. Chakraborty JN, Chawla A, Vyas N. Surgical interventions in female urethral strictures: a comprehensive literature review. Int Urogynecol J. 2022;33(3):459-485. doi:10.1007/s00192-021-04906-8.

6. Borchert A, Jamil M, Perkins S, Raffee S, Atiemo H. Vaginal free graft dorsal onlay urethroplasty. Urology. 2022;159:256. doi:10.1016/j.urology.2021.06.004.

7. Higuchi M, Horiguchi A, Ashiya M, et al. Vaginal flap urethroplasty and dorsal onlay buccal mucosal graft urethroplasty for female urethral stricture: a single-center experience. Int J Urol. 2026;33(5):e70477. doi:10.1111/iju.70477.

8. West C, Lawrence A. Female urethroplasty: contemporary thinking. World J Urol. 2019;37(4):619-629. doi:10.1007/s00345-018-2564-4.

9. Gaur AS, Tarigopula V, Mandal S, et al. Comparison of ventral inlay and dorsal onlay urethroplasty for female urethral stricture. Urology. 2024;193:46-50. doi:10.1016/j.urology.2024.06.046.

10. Hajebrahimi S, Maroufi H, Mostafaei H, Salehi-Pourmehr H. Reconstruction of the urethra with an anterior vaginal mucosal flap in female urethral stricture. Int Urogynecol J. 2019;30(12):2055-2060. doi:10.1007/s00192-019-03910-3.

11. Romero-Maroto J, Verdú-Verdú L, Gómez-Pérez L, et al. Lateral-based anterior vaginal wall flap in the treatment of female urethral stricture: efficacy and safety. Eur Urol. 2018;73(1):123-128. doi:10.1016/j.eururo.2016.09.029.

12. Lane GI, Smith AL, Stambakio H, et al. Treatment of urethral stricture disease in women: a multi-institutional collaborative project from the SUFU research network. Neurourol Urodyn. 2020;39(8):2433-2441. doi:10.1002/nau.24507.

13. Sarin I, Narain TA, Panwar VK, et al. Deciphering the enigma of female urethral strictures: a systematic review and meta-analysis of management modalities. Neurourol Urodyn. 2021;40(1):65-79. doi:10.1002/nau.24584.

14. Khawaja AR, Dar YA, Bashir F, et al. Outcome of dorsal buccal graft urethroplasty in female urethral stricture disease (FUSD): our institutional experience. Int Urogynecol J. 2022;33(3):697-702. doi:10.1007/s00192-021-04840-9.

15. Berdondini E, Eissa A, Margara A, et al. Ventral onlay buccal mucosa graft urethroplasty for female urethral stricture: medium-term results in a single surgeon experience. Urology. 2024;193:194-200. doi:10.1016/j.urology.2024.06.045.

16. Kumar L, Thakur A, Agarwal S, et al. Buccal versus vaginal graft urethroplasty in female urethral stricture: a systematic review and meta-analysis. Int Urogynecol J. 2025;36(11):2121-2132. doi:10.1007/s00192-025-06171-5.

17. Wessells H, Morey A, Souter L, Rahimi L, Vanni A. Urethral stricture disease guideline amendment (2023). J Urol. 2023;210(1):64-71. doi:10.1097/JU.0000000000003482.

18. Kowalik C, Stoffel JT, Zinman L, Vanni AJ, Buckley JC. Intermediate outcomes after female urethral reconstruction: graft vs flap. Urology. 2014;83(5):1181-1185. doi:10.1016/j.urology.2013.12.052.

19. Chakraborty JN, Enganti B, Nayak P. Female urethroplasty: a critical review of indications, techniques and concerns. Int Urogynecol J. 2026;37(4):823-833. doi:10.1007/s00192-025-06415-4.

20. Waterloos M, Lumen N, Ockrim JL, et al. "Diagnostics, reconstructive approaches, and outcomes in female urethroplasty patients." BJU Int. 2025;135(6):1025-1030. doi:10.1111/bju.16701

21. European Association of Urology. "EAU Guidelines on Urethral Strictures: Disease Management in Females." 2026, section 7.3. Guideline

22. Waterloos M, Verla W. "Female urethroplasty: a practical guide emphasizing diagnosis and surgical treatment of female urethral stricture disease." Biomed Res Int. 2019;2019:6715257. doi:10.1155/2019/6715257

23. Gormley EA. "Vaginal flap urethroplasty for female urethral stricture disease." Neurourol Urodyn. 2010;29 Suppl 1:S42-S45. doi:10.1002/nau.20814

24. Blaivas JG, Santos JA, Tsui JF, et al. "Management of urethral stricture in women." J Urol. 2012;188(5):1778-1782. doi:10.1016/j.juro.2012.07.042