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Dorsal Onlay Buccal Mucosal Graft Urethroplasty for BNC and VUAS

Dorsal onlay buccal mucosal graft urethroplasty (D-BMGU) has emerged as a key option for managing refractory VUAS and BNC after radical prostatectomy (with or without radiation), as well as posterior urethral stenosis after endoscopic prostate procedures (TURP, HoLEP, GreenLight).[2][3][4] The technique is particularly valuable in the post-prostatectomy / radiation setting because it is non-transecting, minimizing manipulation of the external urinary sphincter and reducing de novo stress urinary incontinence.[2][4] Anterior-urethra applications (Barbagli, Kulkarni) of the same dorsal-onlay principle are covered separately in the urethral-reconstruction section.

Surgical Technique (Shahrour, post-prostatectomy)​

The Shahrour dorsal-BMG technique for VUAS / BNC at the bladder neck:[10]

  1. Perineal incision with bulbar urethral dissection.
  2. Dorsal dissection carried underneath the pubic bone to reach the vesicourethral anastomosis.
  3. The urethra is opened dorsally through the strictured segment to the bladder neck.
  4. BMG harvested and sutured to the bladder neck at the 11, 12, and 1 o'clock positions — a ski / J-hook needle is useful here for the deep proximal bites.
  5. Dorsal quilting sutures placed through the periosteum of the pubic bone secure the graft.
  6. The graft is sutured to the urethral edges in a continuous fashion.

This approach avoids extensive urethral mobilization, reduces the risk of rectal injury, and eliminates the need for a combined abdominoperineal approach.[10]

Outcomes — VUAS / BNC (Post-Prostatectomy ± Radiation)​

Multi-institutional study of 45 men with VUAS after prostatectomy + radiation (Sterling 2024):[2]

  • 7 recurrences at median 21 mo follow-up.
  • No de novo incontinence — a critical advantage over transecting techniques.
  • Significant improvement in PVR, uroflow, IPSS, and IPSS-QoL.
  • 86.6% satisfaction (GRA +2 or better).

Posterior urethral stenosis after endoscopic prostate procedures (Angulo 2021, n=107):[4]

  • 90.7% success at mean 59 mo.
  • Only 0.9% de novo SUI.
  • Independent predictors of recurrence: postoperative complications (OR 12.5), history of radiation (OR 8.3), and ≥ 2 prior dilatations (OR 8.3).

Substitution urethroplasty with BMG for VUAS / posterior urethral stenosis via perineal approach (Doležel 2024):[3] 3-year stricture recurrence-free survival of 65% (81% with auxiliary DVIU); de novo incontinence in only 2 of 18 continent patients. See also the BMG endourethroplasty page for the matched fully endoscopic approach.

Why Dorsal Placement at the Bladder Neck​

  • Non-transecting — the urethra is opened along its dorsal surface and the graft is laid in; the urethral lumen is never circumferentially divided. The external sphincter mechanism is therefore not disrupted, which is what produces the very low de novo SUI rates seen in the post-prostatectomy series.[2][4]
  • Stable graft bed — the graft is quilted against the periosteum of the pubic bone, which provides a rigid, well-vascularized surface for imbibition and inosculation.[10]
  • Avoids deep abdominal access — unlike combined abdominoperineal repairs, this is done entirely from below.[10]

Complications​

  • De novo SUI: very low (0% in Sterling 2024; 0.9% in Angulo 2021).[2][4]
  • Stricture recurrence: independently associated with prior radiation and ≥ 2 prior dilatations.[4]
  • Donor-site morbidity: mild oral numbness or tightness in 4–9% of BMG harvests overall.[7]

Special Considerations​

  • Radiation history is the strongest independent predictor of recurrence (OR 8.3).[4]
  • Anastomotic urethroplasty is still preferred by 63% of GURS surgeons for short bulbomembranous stenosis after radiotherapy.[1]
  • Graft harvest: 99% of reconstructive urologists prefer buccal mucosa.[1]

Videos​

Dorsal Onlay BMG for VUAS — Operative Technique
Includes ski / J-hook needle use beginning at 3:07
Dorsal Onlay BMG Urethroplasty for VUAS
Operative video demonstration

References​

1. 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

2. 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." The Journal of Urology. 2024;211(4):596-604. doi:10.1097/JU.0000000000003848

3. 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

4. Angulo JC, Dorado JF, Policastro CG, et al. "Multi-Institutional Study of Dorsal Onlay Urethroplasty of the Membranous Urethra After Endoscopic Prostate Procedures: Operative Results, Continence, Erectile Function and Patient Reported Outcomes." Journal of Clinical Medicine. 2021;10(17):3969. doi:10.3390/jcm10173969

7. Pfalzgraf D, Kluth L, Isbarn H, et al. "The Barbagli Technique: 3-Year Experience With a Modified Approach." BJU International. 2013;111(3 Pt B):E132-6. doi:10.1111/j.1464-410X.2012.11399.x

10. Shahrour W, Hodhod A, Kotb A, Prowse O, Elmansy H. "Dorsal Buccal Mucosal Graft Urethroplasty for Vesico-Urethral Anastomotic Stricture Postradical Prostatectomy." Urology. 2019;130:210. doi:10.1016/j.urology.2019.04.022