Phallic Urethra: Prelaminated Buccal Mucosa Graft
Prelaminated buccal mucosa graft (BMG) phallic urethral construction is a staged strategy in which mucosa is grafted onto the future phalloplasty flap before transfer, allowed to vascularize in situ, and later tubularized as the pars pendulans when the flap is raised. The concept is biologically attractive, but clinical outcomes for prelaminated phallic urethras have been disappointing, especially in ALT phalloplasty series where skin-graft prelamination produced the highest urethral complication rates among compared pars pendulans methods.[1][2][3]
This is the atlas page for prelaminated phallic urethral reconstruction, with emphasis on BMG and mucosal graft logic. For the reference tube-in-tube pathway, see Phallic Urethra: Tube-in-Tube and Pars Pendulans Construction. For oral graft biology and harvest principles, see Buccal Mucosa Graft.
Concept
Prelamination, also called prefabrication, tries to convert a free graft into a vascularized component of a flap before the flap is transferred. The central problem is that a circumferential free graft placed into a marginal bed contracts and strictures. Prelamination attempts to avoid this by giving the graft time to inosculate, revascularize, and stabilize before tubularization.[3][4]
| Stage | Goal |
|---|---|
| Stage 1: graft placement | Harvest mucosa or skin and inset it onto the planned flap bed, such as forearm fascia or ALT undersurface |
| Maturation interval | Allow vascular ingrowth and inflammatory settling, often over months rather than weeks |
| Stage 2: flap transfer | Raise the composite flap, tubularize the grafted strip as the pars pendulans, and wrap remaining flap tissue as shaft |
| Urethral continuity | Anastomose the pars pendulans to the pars fixa at the phallus base |
The term "prelaminated BMG" should be used carefully. Much of the high-complication clinical phalloplasty literature involves skin-graft prelamination, not buccal mucosa specifically. BMG is biologically preferable to skin, but robust primary phalloplasty series proving BMG prelamination superiority are lacking.
Why Buccal Mucosa Is Attractive
BMG is the dominant graft material for urethroplasty because it is hairless, pliable, wet-environment tolerant, and supported by a vascular lamina propria. Contemporary GURS practice surveys show broad reconstructive-urology preference for BMG in substitution urethroplasty, and the AUA guideline identifies oral mucosa as first-line graft material when graft urethroplasty is needed.[5][6]
| Feature | Relevance to Phallic Urethra |
|---|---|
| Hairless mucosa | Avoids intraurethral hair, stone, infection, and obstruction risk |
| Thick nonkeratinized epithelium | Better suited to a urinary channel than hair-bearing skin |
| Vascular lamina propria | Supports graft take by imbibition and inosculation |
| Low contracture tendency relative to skin | Theoretically reduces circumferential narrowing |
| Donor availability | Cheek, lip, and lingual mucosa can extend graft length, but donor morbidity and total harvest area still matter |
The 2026 narrative review of buccal mucosa emphasizes that BMG biology remains more nuanced than "good graft material": its regenerative behavior, epithelial thickness, elastin-rich lamina propria, inflammatory profile, and future tissue-engineering directions are still active research areas.[7]
Technique
Stage 1: Prelamination
| Step | Technical Point |
|---|---|
| Mucosa harvest | Harvest buccal mucosa from one or both cheeks depending on desired urethral length |
| Flap-bed preparation | Expose the deep surface of the future phalloplasty flap, such as volar forearm fascia or ALT undersurface |
| Graft inset | Secure the graft to the flap bed without shear; orientation and quilting must preserve a smooth future lumen |
| Maturation | Leave the graft in situ long enough for vascular ingrowth and inflammatory settling; reported intervals often fall around 3-6 months |
| Monitoring | Assess graft take, contraction, scarring, and donor-site suitability before committing to flap transfer |
Stage 2: Phalloplasty
| Step | Technical Point |
|---|---|
| Composite flap elevation | Raise the flap with the prelaminated mucosa incorporated |
| Tubularization | Roll the grafted strip around a catheter to form the pars pendulans |
| Outer shaft construction | Wrap the remaining flap tissue around the urethral tube |
| Transfer | Perform pedicled or free flap transfer according to donor site and center practice |
| Anastomosis | Connect to the pars fixa without tension and protect the junction with vascularized tissue when possible |
The biologic weak point is the graft-flap interface. Even if the graft appears mature, elevation, shear, tubularization, and transfer can compromise perfusion or provoke contraction.
Clinical Outcomes
D'Arpa and colleagues' 93-case ALT urethral-reconstruction series is the most important comparative warning. In that cohort, prelaminated ALT urethra had an 87.5% urethral complication rate, worse than SCIP urethra, RFFF urethra, and selected tube-in-tube ALT. The authors framed flap prelamination as a second-choice strategy with high stricture rates.[1]
Hu and colleagues' 2022 meta-analysis similarly found prelaminated flap techniques associated with significantly higher urethral stricture / stenosis rates than tube-in-tube techniques and a higher need for revision surgery.[3]
| Technique / Material | Series Context | Urethral Signal |
|---|---|---|
| Prelaminated ALT, mostly skin-graft experience | D'Arpa 2019, 8 patients | 87.5% urethral complication rate[1] |
| Prelaminated flap, meta-analysis | Hu 2022, pooled phalloplasty literature | Higher stricture / stenosis rate and more revision than tube-in-tube[3] |
| Tube-in-tube RFFF | Largest evidence base | Reference standard, but still high fistula / stricture burden[3][8] |
| Second-flap urethra | ALT shaft with RFFF urethral flap | Intermediate outcomes; D'Arpa reported 37.9% urethral complications[1][9] |
| SCIP urethral flap | ALT urethral-reconstruction series | Best non-tube-in-tube signal in D'Arpa series at 26.3% urethral complications[1] |
| Prelaminated vaginal mucosa on forearm flap | Zhang 2015, 22 patients | 31.8% fistula, 4.5% stricture; promising but single-center and not BMG[2] |
Vaginal Mucosa Variant
Zhang and colleagues described vaginal mucosal graft prelamination for female-to-male urethral reconstruction. Vaginal mucosa was grafted onto the forearm flap and matured for 6 months before phalloplasty. Histology showed similarity to buccal mucosa and urethral epithelium, and the series reported a low 4.5% stricture rate but a 31.8% fistula rate.[2]
This series is important because it suggests that graft material matters. It should not be generalized into a blanket endorsement of prelamination, because it differs from ALT skin-graft prelamination in substrate, graft material, center technique, and patient selection.
Why Prelamination Fails
| Failure Mechanism | Practical Consequence |
|---|---|
| Incomplete graft take | Tubularization converts marginal take into circumferential stricture |
| Graft contraction | Even mature grafts can contract after being rolled into a tube |
| Shear during flap elevation | Separates graft from its induced vascular bed |
| Thick flap substrate | ALT bulk and hair pattern make tube formation less forgiving |
| Skin graft biology | Keratinization, hair, and contracture are worse than mucosal substitutes |
| Uncertain maturation interval | Too little time risks poor take; too much time may allow fibrosis |
The lesson is not that prelamination is impossible; it is that a vascularized-looking graft on a flap bed is not automatically a durable circumferential urethra.
Preclinical Direction
Guo and colleagues tested capsule-based BMG prefabrication in rabbit models. A tissue expander capsule was used as an induced vascular bed, then BMG was placed onto the capsule and later used for tubularized urethral reconstruction. The prefabricated capsule-BMG construct maintained wider urethral caliber than free BMG alone, suggesting that a deliberately induced vascular bed may be more reliable than simple graft-on-flap prelamination.[4][10]
Lauer and colleagues used tissue-engineered mucosa to prelaminate fascial radial forearm flaps for oral reconstruction, demonstrating the broader reconstructive principle of building a mucosal-lined composite flap before transfer. That work was not phalloplasty-specific, but it remains conceptually relevant to future urethral substitutes.[11]
BMG for Secondary Stricture Repair
BMG performs much better as secondary urethral reconstruction tissue than the clinical literature has shown for primary prelaminated phallic urethral construction. These should be treated as separate indications.
| Repair Context | Technique | Reported Signal |
|---|---|---|
| Neophallus anastomotic stricture | Single-stage double-face BMG urethroplasty with dorsal inlay and ventral onlay | Schardein 2020: 75% success in 8 patients[12] |
| Post-phalloplasty anastomotic stricture | One- or two-stage BMG-augmented urethroplasty | Beamer 2021: high success with both one-stage and staged approaches; staged repair favored for poor tissue or prior failure[13] |
| Long complex pendulous strictures | Two-stage urethroplasty with BMG augmentation and later tubularization | Schardein 2022: 12% failure in 17 patients; many had prior BMG used during phalloplasty prelamination[14] |
This is the most clinically mature role for BMG in post-phalloplasty urethral care: revision of strictures after the initial urethral strategy has failed.
Current Role
| Scenario | Recommendation |
|---|---|
| RFFF candidate accepts forearm scar and UL risk | Prefer tube-in-tube RFFF or center-specific staged urethral plan rather than experimental primary prelamination |
| ALT shaft desired | Prefer SCIP / second-flap urethra or staged skin-graft urethroplasty at experienced centers; avoid assuming prelamination lowers risk[15] |
| Prelaminated skin-graft ALT under consideration | Counsel that published complication rates are high and the method is a fallback, not first-line |
| Vaginal mucosa available | Consider only in centers familiar with the technique; data are promising but limited |
| Failed phalloplasty urethra | BMG is a strong option for secondary single-stage or staged stricture repair |
| Future tissue-engineered mucosa | Conceptually attractive, but not ready to replace established phalloplasty urethral strategies |
Operative Pearls
- Do not conflate BMG success in stricture repair with proven success for primary phallic urethral prelamination.
- Distinguish graft material from technique: skin-graft prelamination, vaginal mucosa prelamination, and BMG prelamination are not interchangeable.
- If prelamination is used, protect the graft-flap interface from shear during both maturation and flap elevation.
- Treat ALT prelamination as a high-risk salvage strategy unless local outcomes prove otherwise.
- Favor BMG for secondary stricture reconstruction when tissue quality and patient goals support urethral salvage.
- Keep the BMG foundations page as the source of truth for oral harvest biology, donor morbidity, and non-GAS urethroplasty use.
References
1. D'Arpa S, Claes K, Lumen N, et al. Urethral reconstruction in anterolateral thigh flap phalloplasty: a 93-case experience. Plast Reconstr Surg. 2019;143(2):382e-392e. doi:10.1097/PRS.0000000000005278
2. Zhang YF, Liu CY, Qu CY, et al. Is vaginal mucosal graft the excellent substitute material for urethral reconstruction in female-to-male transsexuals? World J Urol. 2015;33(12):2115-2123. doi:10.1007/s00345-015-1562-z
3. Hu CH, Chang CJ, Wang SW, Chang KV. A systematic review and meta-analysis of urethral complications and outcomes in transgender men. J Plast Reconstr Aesthet Surg. 2022;75(1):10-24. doi:10.1016/j.bjps.2021.08.006
4. Guo HL, Jia ZM, Wang L, et al. Tubularized urethral reconstruction using a prevascularized capsular tissue prelaminated with buccal mucosa graft in a rabbit model. Asian J Androl. 2019;21(4):381-386. doi:10.4103/aja.aja_43_19
5. 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
6. 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
7. 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. doi:10.1016/j.urology.2026.03.015
8. Gottlieb L, Cripps C. An update on gender-affirming phallus construction using the radial forearm free-flap. Neurourol Urodyn. 2023;42(5):963-972. doi:10.1002/nau.25103
9. van der Sluis WB, Smit JM, Pigot GLS, et al. Double flap phalloplasty in transgender men: surgical technique and outcome of pedicled anterolateral thigh flap phalloplasty combined with radial forearm free flap urethral reconstruction. Microsurgery. 2017;37(8):917-923. doi:10.1002/micr.30190
10. Guo HL, Wang L, Jia ZM, et al. Tissue expander capsule as an induced vascular bed to prefabricate an axial vascularized buccal mucosa-lined flap for tubularized posterior urethral reconstruction: preliminary results in an animal model. Asian J Androl. 2020;22(5):459-464. doi:10.4103/aja.aja_133_19
11. Lauer G, Schimming R, Gellrich NC, Schmelzeisen R. Prelaminating the fascial radial forearm flap by using tissue-engineered mucosa: improvement of donor and recipient sites. Plast Reconstr Surg. 2001;108(6):1564-1572. doi:10.1097/00006534-200111000-00019
12. Schardein J, Beamer M, Hughes M, Nikolavsky D. Single-stage double-face buccal mucosal graft urethroplasty for neophallus anastomotic strictures. Urology. 2020;143:257. doi:10.1016/j.urology.2020.06.010
13. Beamer MR, Schardein J, Shakir N, et al. One or two stage buccal augmented urethroplasty has a high success rate in treating post phalloplasty anastomotic urethral stricture. Urology. 2021;156:271-278. doi:10.1016/j.urology.2021.05.045
14. Schardein J, Beamer M, Kittleman MA, Nikolavsky D. Staged urethroplasty for reconstruction of long complex pendulous strictures of a neophallic urethra. Urology. 2022;164:e309-e311. doi:10.1016/j.urology.2021.12.029
15. Robinson I, Chao BW, Blasdel G, et al. Anterolateral thigh phalloplasty with staged skin graft urethroplasty: technique and outcomes. Urology. 2023;177:204-212. doi:10.1016/j.urology.2023.03.038