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Dorsal Onlay Oral Mucosal Graft Urethroplasty

Dorsal onlay oral mucosal graft (OMG) urethroplasty is a widely used substitution urethroplasty technique for anterior urethral strictures not amenable to excision and primary anastomosis. Barbagli described dorsal free skin grafting in 1996 (see the History of Urethral Surgery); his 1998 dorsal-onlay series also used buccal mucosa in six patients.[29][2] A free oral mucosal graft is placed on the dorsal surface of the opened urethra and secured against the corpora cavernosa.[1][2] In a 2024 GURS survey, 66% of respondents preferred dorsal placement for bulbar grafting (134 responses from 350 invitees).[3] For bulbar grafting, EAU 2026 strongly recommends choosing dorsal, dorsolateral or ventral placement according to surgical practice, expertise and intraoperative findings.[3][4][23]

For graft details, see Buccal Mucosa Graft. For the augmented anastomotic alternative, see Augmented Anastomotic Urethroplasty. For the muscle-sparing one-sided variant for long-segment / panurethral disease, see Muscle-Sparing Urethroplasty.

Indications​

  • Bulbar urethral strictures. For strictures too long for tension-free EPA, suitability depends on location and tissue mobility; EAU 2026 strongly recommends free graft urethroplasty when EPA is unsuitable.[23] For short strictures unrelated to straddle injury, it weakly recommends non-transecting EPA or free graft urethroplasty over transecting EPA.[1][5][23]
  • Penile urethral strictures. One-stage dorsal onlay or staged repair may be selected according to stricture and tissue characteristics. EAU 2026 strongly recommends counselling that a planned single-stage repair may require conversion to a staged procedure when adverse findings appear intraoperatively.[6][7][23]
  • Panurethral or long-segment strictures. The Kulkarni modification is one option. EAU 2026 weakly recommends panurethral reconstruction in specialised centres and combining techniques when one approach cannot address the full stricture.[8][9][23]
  • Selected nonobliterative anastomotic / bulbomembranous stenosis after both prostatectomy and radiation[10]
  • Etiology and tissue quality guide selection; single-stage oral mucosa remains an option in lichen sclerosus when local conditions are suitable.[23]

The AUA Urethral Stricture Disease Guideline (2023 amendment) states that surgeons should use oral mucosa as the first choice when using grafts and may use buccal or lingual mucosal grafts as equivalent alternatives .[12]

Why buccal / oral mucosa?​

Buccal mucosa has these properties as a graft material:[1][13]

  • Favorable mucosal wound-healing biology, although clinical repairs can still scar or recur
  • Thick non-keratinized epithelium with thin lamina propria, facilitating graft take via imbibition and inosculation
  • Adapted to a moist environment, although infection can still compromise reconstruction
  • Accessible donor site, with possible pain, numbness and restricted mouth opening
  • 99% of respondents in the GURS survey selected buccal mucosa as the primary graft site[3]

Surgical Technique​

Three principal dorsal approaches exist, each with distinct technical features.

1. Barbagli technique (classic dorsal onlay)​

  • Lithotomy position; perineal midline incision.
  • The bulbar urethra is fully mobilized circumferentially from the corpora cavernosa.
  • The urethra is rotated 180° to expose the dorsal surface.
  • A dorsal urethrotomy is performed through the strictured segment.
  • The buccal mucosal graft (harvested from the inner cheek) is quilted to the tunica albuginea of the corpora cavernosa, providing a well-vascularized bed; one urethrotomy margin is then sutured to the corresponding graft edge before the urethra is rotated back.[31]
  • The urethra is rotated back, and the remaining urethrotomy margin is sutured to the free graft edge and corporal bed, completing the augmented lumen. The ventral urethral wall remains intact in the classic dorsal-onlay operation.[1][2][14][15]

The original 1996 report placed free skin grafts dorsally against the corpora cavernosa to reduce urethrocele formation. It included 25 men, 12 with penile and 13 with bulbar strictures (6 dorsal tube grafts and 7 dorsal patch grafts in the bulbar group). At a mean follow-up of 35.8 months, 5 temporary fistulas seen on postoperative urethrography had closed spontaneously, and no post-void dribbling or diminished ejaculation suggesting graft weakening was reported.[29] Buccal mucosa was reported as a dorsal onlay graft in the 1998 series.[2]

Dorsal mobilization can be difficult after repeated, deep internal urethrotomies at 12 o'clock, which may leave the urethral mucosa adherent to the tunica albuginea, or when an indwelling urethral stent impedes dorsal exposure; a deep, flat perineum in an obese patient can also make separation from the corpora difficult. In these settings, a ventral or lateral approach is advised rather than forcing the dorsal dissection, and any tunica albuginea injury should be recognized and repaired.[28]

A published variant secures the graft with fibrin glue rather than extensive quilting. In a one-sided dissection, 2 mL of fibrin glue is spread over the exposed tunica albuginea before the graft is laid on the bed; the graft apices are sutured to the urethrotomy apices and its margins to the urethral mucosal plate.[30] After the urethra is rotated back over the graft, the margins are stabilized to the corpora with interrupted 5-0 polyglactin sutures, and a second 2 mL layer of fibrin glue is applied over the suture line.[30] The authors describe glue fixation as simplifying the operation compared with placing numerous interrupted quilting sutures; this has not been directly compared with suture quilting for outcome.[25]

2. Kulkarni technique (dorsolateral onlay, one-sided dissection)​

  • Designed for long-segment and panurethral strictures.
  • The urethra is mobilized from one side only, preserving the contralateral blood supply and the central perineal tendon attachments.
  • Penile invagination through the perineal incision allows access to the entire anterior urethra without a separate penile incision.
  • The graft is placed in a dorsolateral position.
  • A retrospective comparison reported shorter operating time and less blood loss than circumferential dissection.[8][9][16]

3. Asopa technique (dorsal inlay)​

  • A ventral sagittal urethrotomy is performed without mobilizing the urethra from the corpora.
  • Through this ventral opening, a dorsal urethrotomy is made, and the graft is inlaid into the dorsal wall and sutured to the corpora cavernosa.
  • Avoids circumferential urethral mobilization entirely.[1]

Penile repairs. In an editorial comment, Brandes reports that insufficient penile stretch while suturing a dorsal graft produced ventral chordee in his experience, and he places a temporary glans-traction stitch before suturing to maintain stretch throughout the case.[26]

Graft harvest​

  • Buccal mucosa is harvested from the inner cheek (most common); in an 18-patient modified Barbagli series, oral grafts ranged from 2.5–13 cm in length.[2][14]
  • For long grafts, 56% of surgeons prefer harvesting from both cheeks.[3]
  • The donor site may be left open or closed. In a randomized trial of 135 patients, non-closure was noninferior to closure for intensity and quality of oral pain.[17]

Outcomes​

TechniqueSuccessFollow-upKey Findings
Dorsal onlay (Barbagli) — bulbar series plus a separately reported modified technique described for penile strictures[1][2][5][14]Modified technique: about 83% success among 18 followed (22 treated); separate 1998 bulbar mixed-graft cohort: 34/37 (92%; 31 skin, 6 buccal)1998 cohort mean 21.5 mo overall, buccal subgroup mean 13.5 mo; 32% oral-graft recurrence cohort mean 134 moMost dorsal oral-graft series report <20% recurrence at short to medium follow-up; recurrence reached 32% with extended follow-up in the systematic review
Dorsal onlay — penile[6][7]86.6% for penile dorsal buccal onlay in a systematic reviewvariableStaged repair is preferred for complex cases; selected one-stage dorsal onlay can be feasible
Kulkarni (dorsolateral) — long / panurethral[8][9][16]87–90% across cited series; 2025 mixed-graft series 89.7% overall (oral mucosa 80.0%, penile skin 95.8%)12–60 mo across series; 2025 median 12 moA separate retrospective comparison reported shorter operating time and less blood loss versus classic Barbagli
Dorsal onlay — after both prostatectomy and radiation[10]84% (7/45 recurrences)median 21 mo among those without recurrence29/45 had preoperative SUI; 10/45 were known continent and 6/45 had unknown baseline status because of suprapubic drainage; no de novo SUI was observed among the 10 known continent men
Dorsal vs ventral onlay — meta-analysis[19]RR 1.00 (no difference)variableNo significant success difference; imprecise sexual outcomes

A single-center retrospective study included 507 bulbar graft repairs: 221 augmented anastomotic and 286 pure dorsal onlay. The combined success was 93.9% at mean 78.9 months. Augmented anastomotic repair was associated with recurrence after adjustment (HR 4.8, p = 0.002), and the institution changed its technique over time.[20]

A 2025 meta-analysis of 8 studies (655 patients) found no significant difference in success between dorsal and ventral onlay (RR 1.00, 95% CI 0.94–1.06), with comparable Qmax at 3 and 12 months. However, transient ED was significantly lower with the ventral technique (RR 0.24, p = 0.006), while the estimate for permanent ED was too imprecise to establish a difference or equivalence (RR 0.57, 95% CI 0.03–12.20).[19]

Complications​

  • Stricture recurrence. Most dorsal oral-graft series reported <20% at short to medium follow-up; one oral-graft cohort reported 32% recurrence at mean 134-month follow-up.[5]

  • Sexual-function change. Counsel and measure against baseline; transient and persistent ED estimates vary substantially between cohorts.[18][19][21]

  • 90-day complications. 17.6% overall in a retrospective series of 165 bulbar onlay repairs (15.5% dorsal, 19.4% ventral).[18]

  • Postvoid dribbling. Reported in 45% after one-sided dorsal buccal onlay for long-segment or panurethral strictures in one retrospective series.[9]

  • Chordee. Transient chordee was reported in 25% after one-sided repair of long-segment or panurethral strictures in a retrospective series.[9]

  • Fistula. One case in a 53-patient mixed anterior buccal-graft cohort (1.9%).[11]

  • Donor-site morbidity. Oral pain (median VAS 3/10 at median 2.1 months in 97/97 assessed; median 0 at median 17 months in 70/97 assessed), transient numbness (approximately 9%), temporary difficulty with mouth opening; generally self-limited.[14][17][21]

The EAU-panel systematic review (41 studies, 3,683 patients, low-quality evidence) found no statistically significant difference in re-stricture rates among compared bulbar graft placements; secondary functional outcomes were too sparsely reported for firm comparison.[5]

Postoperative Management​

Preoperative infection or bacteriuria is treated according to culture, and an intraoperative prophylactic regimen is chosen for local resistance patterns. EAU 2026 finds no evidence that routine prolonged antibiotics through catheter removal reduce infections.[24]

A urethral catheter commonly remains for two to three weeks, adjusted to repair complexity and healing. Assess for extravasation with validated urethrography before removal; maintain drainage and reassess significant leakage. Follow-up includes symptoms, uroflowmetry and PVR, with anatomical reassessment guided by the reconstruction and recurrence risk.[24] EAU 2026 strongly recommends at least one year of follow-up and weakly recommends a risk-adjusted protocol.[32] Its proposed schedule for graft repairs includes PROMs and flowmetry at 3, 12 and 24 months and five years, with anatomic evaluation at 3, 12 and 24 months.[32]

Patient-reported voiding improvement is common. Sexual recovery is variable, and no fixed recovery date can be promised.[21]

Special Considerations​

  • Lichen sclerosus. EAU 2026 weakly recommends single-stage oral mucosa graft urethroplasty when local conditions permit, and staged reconstruction remains an option for adverse local conditions.[23] AUA advises against genital skin for reconstruction of LS-proven strictures ; EAU advises against genital skin for augmentation penile urethroplasty in LS-related strictures .[12][23]
  • Pediatric. Dorsal onlay BMG urethroplasty (Barbagli and Kulkarni techniques) is safe and feasible in children with long-segment non-hypospadias strictures, with success rates of 83–88% at median follow-up 90–96 months in a retrospective series of 28 circumcised children.[22]
  • After prostatectomy plus radiation. The 45-patient Sterling retrospective cohort supports feasibility in selected nonobliterative stenoses; 7 recurred. At baseline, 29 had SUI, 10 were known continent, and 6 had unknown status because of suprapubic drainage. No de novo SUI was observed among the 10 known continent men; 17/45 men subsequently underwent AUS placement. In Sterling et al.'s reported posterior repair, the urethra was dissected dorsolaterally from one side, dorsal scar excision was limited to the 11-to-1-o’clock sector, and cautery was avoided near the membranous urethra and cavernous nerve mesh. The authors did not use this repair for obliterative stenosis or anastomotic disruption and would not offer it to poor surgical candidates or patients with bladder capacity <100 mL, fistula, or radionecrosis.[10]
  • Incomplete membranous strictures. For catheter-related narrowing or an incomplete urethral rupture, splitting the stricture exactly in the midline and augmenting it with a buccal-mucosa onlay, an inner-preputial patch, or a staged mesh graft has been described. Staying in the midline is intended to preserve tissue important to erectile function and urethral blood flow. This has not been validated against alternative approaches and should not be extended to a complete distraction defect.[27]

Videos​

Dorsal Onlay BMG Urethroplasty
Operative technique
Dorsal Onlay BMG Urethroplasty
Step-by-step demonstration
Dorsal Onlay BMG Urethroplasty
Operative technique

References​

  1. Horiguchi A. Substitution urethroplasty using oral mucosa graft for male anterior urethral stricture disease: current topics and reviews. Int J Urol. 2017;24(7):493-503. doi:10.1111/iju.13356.

  2. Barbagli G, Palminteri E, Rizzo M. Dorsal onlay graft urethroplasty using penile skin or buccal mucosa in adult bulbourethral strictures. J Urol. 1998;160(4):1307-9. doi:10.1016/s0022-5347(01)62522-9

  3. Berg C, Singh A, Hu P, et al. Current trends in the use of buccal grafts during urethroplasty among Society of Genitourinary Reconstructive Surgeons. Urology. 2024;191:139-143. doi:10.1016/j.urology.2024.06.019.

  4. Cotter KJ, Hahn AE, Voelzke BB, et al. Trends in urethral stricture disease etiology and urethroplasty technique from a multi-institutional surgical outcomes research group. Urology. 2019;130:167-174. doi:10.1016/j.urology.2019.01.046.

  5. Barratt R, Chan G, La Rocca R, et al. Free graft augmentation urethroplasty for bulbar urethral strictures: which technique is best? A systematic review. Eur Urol. 2021;80(1):57-68. doi:10.1016/j.eururo.2021.03.026.

  6. Patterson JM, Chapple CR. Surgical techniques in substitution urethroplasty using buccal mucosa for the treatment of anterior urethral strictures. Eur Urol. 2008;53(6):1162-71. doi:10.1016/j.eururo.2007.10.011.

  7. Jasionowska S, Bochinski A, Shiatis V, et al. Anterior urethroplasty for the management of urethral strictures in males: a systematic review. Urology. 2022;159:222-234. doi:10.1016/j.urology.2021.09.003.

  8. Takekawa K, Horiguchi A, Shinchi M, et al. One-sided dorsal onlay urethroplasty with penile invagination (Kulkarni urethroplasty) for complex anterior urethral strictures: a single-center experience. Int J Urol. 2025;32(6):749-755. doi:10.1111/iju.70048.

  9. Spencer J, Blakely S, Daugherty M, et al. Clinical and patient-reported outcomes of 1-sided anterior urethroplasty for long-segment or panurethral strictures. Urology. 2018;111:208-213. doi:10.1016/j.urology.2017.08.029.

  10. Sterling J, Simhan J, Flynn BJ, et al. Multi-institutional outcomes of dorsal onlay buccal mucosal graft urethroplasty in patients with postprostatectomy, postradiation anastomotic stenosis. J Urol. 2024;211(4):596-604. doi:10.1097/JU.0000000000003848.

  11. Levine LA, Strom KH, Lux MM. Buccal mucosa graft urethroplasty for anterior urethral stricture repair: evaluation of the impact of stricture location and lichen sclerosus on surgical outcome. J Urol. 2007;178(5):2011-5. doi:10.1016/j.juro.2007.07.034.

  12. 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.

  13. Sterling J, Hecksher D, Hayden C, et al. Buccal mucosa — a narrative review: how does it work, how is it used, what is coming next. Urology. 2026:S0090-4295(26)00169-X. doi:10.1016/j.urology.2026.03.015.

  14. Pfalzgraf D, Kluth L, Isbarn H, et al. The Barbagli technique: 3-year experience with a modified approach. BJU Int. 2013;111(3 Pt B):E132-6. doi:10.1111/j.1464-410X.2012.11399.x.

  15. Pansadoro V, Emiliozzi P, Gaffi M, et al. Buccal mucosa urethroplasty in the treatment of bulbar urethral strictures. Urology. 2003;61(5):1008-10. doi:10.1016/s0090-4295(02)02585-2.

  16. Kartal I, Çimen S, Kokurcan A, et al. Comparison between dorsal onlay and one-sided dorsolateral onlay buccal mucosal graft urethroplasty in long anterior urethral strictures. Int J Urol. 2020;27(9):719-724. doi:10.1111/iju.14286.

  17. Soave A, Dahlem R, Pinnschmidt HO, et al. Substitution urethroplasty with closure versus nonclosure of the buccal mucosa graft harvest site: a randomized controlled trial with a detailed analysis of oral pain and morbidity. Eur Urol. 2018;73(6):910-922. doi:10.1016/j.eururo.2017.11.014.

  18. Shalkamy O, Elatreisy A, Salih E, et al. Erectile and voiding function outcomes after buccal mucosa graft urethroplasty for long-segment bulbar urethral stricture: ventral versus dorsal onlay technique. World J Urol. 2023;41(1):205-210. doi:10.1007/s00345-022-04220-y.

  19. Hassan AA, Soliman AM, Shouman HA, et al. Dorsal- vs ventral-onlay buccal mucosal graft urethroplasty for urethral strictures: a meta-analysis. BJU Int. 2025;136(3):385-394. doi:10.1111/bju.16811.

  20. Redmond EJ, Hoare DT, Rourke KF. Augmented anastomotic urethroplasty is independently associated with failure after reconstruction for long bulbar urethral strictures. J Urol. 2020;204(5):989-995. doi:10.1097/JU.0000000000001177.

  21. D'hulst P, Muilwijk T, Vander Eeckt K, Van der Aa F, Joniau S. Patient-reported outcomes after buccal mucosal graft urethroplasty for bulbar urethral strictures: results of a prospective single-centre cohort study. BJU Int. 2020;126(6):684-693. doi:10.1111/bju.15131.

  22. Patil N, Javali T. Paediatric buccal mucosal graft urethroplasty for non-hypospadias urethral strictures: a single centre experience with long term outcomes. Urology. 2021;158:174-179. doi:10.1016/j.urology.2021.06.029.

23. EAU Guidelines on Urethral Strictures, 2026: disease management in males. https://uroweb.org/guidelines/urethral-strictures/chapter/disease-management-in-males. Accessed September 12, 2026.

24. EAU Guidelines on Urethral Strictures, 2026: perioperative care. https://uroweb.org/guidelines/urethral-strictures/chapter/perioperative-care-of-urethral-surgery. Accessed September 12, 2026.

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  4. Barbagli G, Lazzeri M. Repair of bulbar urethra using the Barbagli technique. In: Schreiter F, Jordan GH, eds. Urethral Reconstructive Surgery. Springer; 2006:181-187. doi:10.1007/3-540-29385-X_22

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  6. Barbagli G, Balò S, Sansalone S, Lazzeri M. "Dorsal onlay graft bulbar urethroplasty using buccal mucosa." Afr J Urol. 2016;22(1):5–10. doi:10.1016/j.afju.2015.09.003

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  8. European Association of Urology. "EAU Guidelines on Urethral Strictures: Follow Up." EAU Guidelines. 2026. https://uroweb.org/guidelines/urethral-strictures/chapter/followup