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BMG Endourethroplasty

BMG endourethroplasty describes transurethral placement of buccal mucosa without an external urethral incision. Posterior grafting remains supported mainly by small observational series and technical reports. Distal/fossa-navicularis inlay urethroplasty and injectable micrografts involve different sites and techniques; their results cannot be pooled as posterior-stenosis evidence.

Transverse mucosal realignment (TUITMR) is a separate, nongraft technique.

Posterior grafting​

Chiou's 1988 three-patient report described endoscopic scar-bed preparation followed by a full-thickness preputial graft retained with a balloon catheter. It established historical feasibility, not a standard treatment or a durable population-level success estimate.[1]

Doležel's retrospective series included 38 patients treated during 1999–2022: 27 perineal repairs and 11 endourethroplasties. Three-year recurrence-free survival was 65% overall, with estimates of 63% and 73% for the respective approaches. The 23-year recruitment period is not 23 years of follow-up for every patient. Selection and small groups preclude a conclusion of equivalence or superiority.[2]

When the authors counted auxiliary DVIU for recurrence as part of treatment, the overall three-year result became 81%. That outcome includes additional procedures and should not be labeled single-operation success. New incontinence occurred in 2/18 patients continent before surgery across both approaches; it is not an endourethroplasty-specific estimate.[2]

Selection limits

EAU advises against endoluminal treatment of a completely obliterated posterior stenosis. Historical or experimental tubular graft descriptions do not justify attempted endoscopic recanalization as routine care. Assess radiation injury, fistula, tissue vascularity, bladder function and continence before selecting reconstruction.[3]

Endoscopic BMG with transurethral suturing​

Ungerer/Warner reported one radiated patient with an 8 mm membranous stenosis. Their technical sequence was:[4]

  1. Dilate sufficiently for safe instrumentation and prepare a superficial approximately 1 cm-wide strip of recipient mucosa extending across the stenosis.
  2. Harvest buccal mucosa and position the graft for transurethral delivery.
  3. Use the RD180 suturing device and a pulley-style suture to draw the graft into the prepared bed, then secure it endoscopically.
  4. Maintain catheter drainage during healing; the reported catheter duration was 4 weeks.

The procedure took 2.5 hours, with 50 mL estimated blood loss and same-day discharge. Cystoscopy at 10 weeks showed viable graft; Qmax improved from 4 to 20 mL/s, with no recurrence at 6 months. These are single-case observations, not evidence of established safety, minimal SUI risk or superiority to other repairs. Recipient-bed preparation must protect the sphincter and adjacent structures; the superficial endoscopic bed is not the same dissection as a pubic periosteal bed in a specific open repair.[4]

Distal urethral inlay grafts​

Transurethral ventral and dorsal inlay BMG techniques for distal/fossa-navicularis strictures aim to preserve the glans while replacing diseased lining. They belong to the distal reconstruction pathway, not the BNC/VUAS treatment evidence base.[5][6][7]

The international ventral-inlay cohort enrolled 68 patients; 57 had at least 12 months of follow-up, and 54/57 (95%) were successful, at median follow-up of 17 months. Do not report 95% of all 68 or add this series to subsequent same-group reports as independent patients without establishing overlap.[6]

Differences in graft location, fixation and catheter duration are technique-specific. They should not be carried over from a distal repair to a radiated posterior stenosis.

Minced or liquid buccal grafts​

Liquid grafting suspends mechanically minced buccal micrografts in a carrier for endoscopic placement after urethrotomy. Animal studies demonstrated engraftment, but engraftment is not synonymous with a durable clinical cure. In the randomized rabbit validation, radiographic changes did not establish a clear functional superiority despite more histologic engraftment.[8][9]

Human pilot data now exist. Gaur's 2025 uncontrolled 30-patient study reported a modified minced-graft approach; follow-up attrition and the small sample limit interpretation. It does not establish efficacy for posterior BNC/VUAS or justify combining micrografts with a drug-coated balloon. The study's erratum corrects its description of an earlier Vaddi study, not its own pilot outcome. See the liquid minced buccal graft page for the clinical and preclinical evidence.[10][11]

Position in care​

Mucosal grafting requires viable tissue contact and secure fixation. Avoiding external dissection does not prove preservation of continence or eliminate operative injury. Document the stenosis site, prior continence, radiation, outcome definition and any additional procedures when interpreting results.

A 2024 meta-analysis of 40 endoscopic VUAS studies (1,452 patients) estimated success at 72.8%, or 62.9% after adjustment for publication bias; it does not support a universal 90% two-year retreatment rate. Current evidence also does not establish an 85–90% advantage for all novel endoscopic procedures over standard treatment.[12]

Discuss established endoscopic treatment for nonobliterative disease and open or robotic reconstruction for appropriate refractory cases. Reconstruction does not invariably require a combined abdominoperineal approach. Technique selection is individualized, and posterior endourethroplasty remains a specialist option requiring more comparative and long-term evidence.[3]

References​

1. Chiou RK. "Endourethroplasty in the Management of Complicated Posterior Urethral Strictures." The Journal of Urology. 1988;140(3):607-10. doi:10.1016/s0022-5347(17)41735-6

2. Doležel J, Hrabec R, Uher M, et al. "Substitution Urethroplasty With Buccal Mucosal Graft in the Management of Stricture of Vesicourethral Anastomosis or Membranous Urethra: Single-Institution Long-Term Experience With Perineal Approach and Endourethroplasty." Urology. 2024;192:126-132. doi:10.1016/j.urology.2024.05.034

3. European Association of Urology. EAU Guidelines on Urethral Strictures. 2026. Disease management in males, sections 6.3.5–6.3.6. Guideline.

4. Ungerer G, Kemble J, Sischka M, Balzano FL, Warner JN. "Endoscopic Urethroplasty Using Buccal Graft for Male Membranous Urethral Stricture." Urology. 2023;181:e200-e203. doi:10.1016/j.urology.2023.05.059

5. Sterling J, Daneshvar M, Nikolavsky D. "Transurethral Ventral Inlay Buccal Mucosa Graft Urethroplasty: Technique and Intermediate Outcomes." BJU International. 2023;132(1):109-111. doi:10.1111/bju.16007

6. Daneshvar M, Simhan J, Blakely S, et al. "Transurethral Ventral Buccal Mucosa Graft Inlay for Treatment of Distal Urethral Strictures: International Multi-Institutional Experience." World Journal of Urology. 2020;38(10):2601-2607. doi:10.1007/s00345-019-03061-6

7. Farrell MR, Campbell JG, Zhang L, Nowicki S, Vanni AJ. "Transurethral Reconstruction of Fossa Navicularis Strictures With Dorsal Inlay Buccal Mucosa Graft Urethroplasty." World Journal of Urology. 2022;40(6):1523-1528. doi:10.1007/s00345-022-03994-5

8. Nikolavsky D, Manwaring J, Bratslavsky G, et al. "Novel Concept and Method of Endoscopic Urethral Stricture Treatment Using Liquid Buccal Mucosal Graft." The Journal of Urology. 2016;196(6):1788-1795. doi:10.1016/j.juro.2016.05.028

9. Scott KA, Li G, Manwaring J, et al. "Liquid Buccal Mucosa Graft Endoscopic Urethroplasty: A Validation Animal Study." World Journal of Urology. 2020;38(9):2139-2145. doi:10.1007/s00345-019-02840-5

10. Gaur AS, Tarigopula V, Mandal S, et al. Modification of minced buccal mucosal graft endourethral urethroplasty: a pilot study. Indian J Urol. 2025;41:131–136. doi:10.4103/iju.iju_519_24.

11. Erratum: Modification of minced buccal mucosal graft endourethral urethroplasty: a pilot study. Indian J Urol. 2025. doi:10.4103/iju.iju_292_25.

12. Delchet O, et al. Post-prostatectomy anastomotic stenosis: systematic review and meta-analysis of endoscopic treatment. BJU Int. 2024. doi:10.1111/bju.16141.