Female Ventral Inlay BMG Urethroplasty
Female ventral inlay BMG urethroplasty (VIBMGU) is a vaginal-sparing technique for female urethral stricture (FUS): the urethra is opened ventrally and a buccal mucosal graft is placed directly into the urethrotomy through the meatus / transurethrally, without incising the anterior vaginal wall and without periurethral fascial flap creation. Reported success is 85–95% with the shortest operative time, lowest blood loss, and lowest pain scores among the three ventral techniques.[1][2][3]
For the closely related ventral onlay approach, see Female Ventral Onlay Urethroplasty. For the dorsal alternative, see Female Dorsal Onlay Urethroplasty. For the broader ladder, see Female DVIU and Urethral Dilation.
Inlay vs Onlay — the Defining Distinction
Both techniques place the graft on the ventral surface; the difference is access and graft fixation:
| Feature | Ventral Inlay (VIBMGU) | Ventral Onlay (VOBMGU) |
|---|---|---|
| Vaginal wall incision | No — meatal / transurethral access | Yes — anterior vaginal wall opened |
| Periurethral fascial flaps | None | Elevated and closed over graft |
| Graft support | Native periurethral bed | Fascial-flap bed |
| OR time | Shortest (~ 30 min) | ~ 64–98 min |
| Blood loss | ~ 10 mL | ~ 10–20 mL |
The technique has been independently developed and published by two groups under different names — Mandal / Gaur / Kumaraswamy (India) as "vaginal-sparing VIBMGU" (Kumaraswamy 2022, Gaur 2024, Mandal 2025 RCT) and Sterling / Nikolavsky (USA) as "transurethral ventral inlay BMG" (2023). The operative steps are essentially identical (meatal-only access, 6-o'clock ventral urethrotomy ≥ 24 Fr, double-armed 6-0 PDS proximal fixation, 5-0 polyglactin distal anchor, quilting onto the native periurethral bed); the differences are confined to catheter duration (1 wk Sterling / 1–3 wk Mandal) and emphasized indication (Nikolavsky favors fossa-navicularis / distal disease; Mandal applies broadly across segments).[1][3][5]
Indications
- Recurrent / refractory FUS after failed dilation or DVIU.[7]
- Strictures of any urethral segment (distal / mid / proximal / pan-urethral).
- AUA 2023 endorses urethroplasty for FUS (success 69–95% across techniques).[7]
Particularly advantageous when:
- Vaginal sparing is desired (prior vaginal surgery, atrophy, narrowing concern).[1]
- A shorter, less invasive procedure is preferred.[2]
- Distal / fossa-navicularis location is the indication most strongly supported by the Sterling / Nikolavsky 2023 series; more proximal segments are technically demanding due to limited transurethral exposure.[5]
Technique
- Setup — urethral catheter; meatal stay sutures for retraction.
- Meatal / transurethral access — entirely through the meatus; no vaginal-wall incision.
- Ventral urethrotomy — longitudinal 6 o'clock incision through the entire stricture; cicatrix excised until the lumen is at least 24 Fr.
- BMG harvest — inner cheek; defat / remove fibromuscular tissue. Trim to a triangular or rectangular shape matching the urethrotomy defect.
- Graft delivery and fixation — double-armed 6-0 PDS delivers the graft to the proximal extent of the urethrotomy; secured proximally first, then to both lateral edges. Quilting sutures for spread fixation against the native periurethral tissue.
- Meatal fixation — distal end of the graft secured to the meatus with 5-0 polyglactin.
- Catheter — 16 Fr silicone; same-day discharge possible. Removal at 1 week (Sterling / Nikolavsky) or 3 weeks by surgeon preference (Mandal / Gaur reports both).[3][5]
Technical principles — incise through the entire stricture into healthy tissue; vaginal wall is never incised; graft survives on the native periurethral bed via imbibition / inosculation; technique is inherently simpler and faster than dorsal or ventral onlay.[2]
The Sterling / Nikolavsky 2023 series specifically targeted fossa navicularis and distal urethral strictures (n = 44; 95% patency at mean 36 mo; 2 recurrences had more proximal extension and were salvaged with dorsal onlay; median OR time 120 min); the Mandal / Gaur series applied the same operative steps across distal, mid, proximal, and pan-urethral segments.[1][5]
Outcomes
| Series | n | Technique | Success | Follow-up | Key findings |
|---|---|---|---|---|---|
| Gaur 2024[1] | 46 | Vaginal-sparing VIBMGU | 89.1% | median 27.5 mo (up to 90) | Largest series; equivalent to dorsal onlay (88.9%) |
| Mandal 2025 RCT[2] | 20 (VI arm) | VIBMGU vs DOBMGU | 95% (both arms) | median 21 mo | OR time 30 vs 44.5 min (p < 0.001); blood loss 10 vs 15 mL (p = 0.012); less pain |
| Kumaraswamy 2022[3] | 21 | VIBMGU | 90.5% overall; 85% sustained at 2–5 yr (life-table) | median 42 mo (24–64) | 95% at 1 yr; 0% incontinence |
| Sterling / Nikolavsky 2023[5] | 44 | Same technique; transurethral approach for distal disease | 95% | mean 36 mo | Same-day discharge; catheter at 1 wk; recurrences had proximal extension |
| Gülpınar 2021[4] | 8 | Vaginal-sparing inlay BMG | 87.5% | median 24.6 mo | vs ventral onlay 83.3% / AZ technique 100% in same study |
Functional gains: Qmax 7.7 → 22.6 mL/s; PVR 138 → 24 mL; AUA-SS 27 → 9; 0% de-novo SUI across all reported VI series.[2][3]
Long-Term Durability
The Kumaraswamy 2022 life-table is the strongest long-term signal:[3]
- 95% at 1 yr, 85% sustained at 2 / 3 / 4 / 5 yr.
- Failures at 6 mo and 24 mo; no late failures beyond 2 yr.
The Gaur 2024 series extends individual follow-up to 90 months — the longest in the female urethroplasty literature.[1]
Mandal 2025 — the only RCT
First registered RCT comparing ventral inlay vs dorsal onlay in women:[2]
| Endpoint | Ventral Inlay | Dorsal Onlay | p |
|---|---|---|---|
| Success | 95% | 95% (1 failure each) | NS |
| Operative time | 30 min | 44.5 min | < 0.001 |
| Blood loss | 10 mL | 15 mL | 0.012 |
| Postop pain (VAS 6 h, 24 h) | Lower | Higher | significant |
| De-novo SUI | 0% | 0% | NS |
Established non-inferiority of VI BMGU with substantial peri-operative advantages.
Advantages
- Shortest operative time (median 30 min in the RCT).[2]
- Least blood loss (~ 10 mL).[2]
- Less postoperative pain.[2]
- Same-day discharge possible (transurethral approach).[5]
- Shorter catheterization — 1 wk in the transurethral approach vs ~ 3 wk for onlay.[5]
- Technically simpler — no periurethral fascial dissection or flap creation.[1]
- Sphincter preservation — ventral approach leaves the dorsal sphincter mechanism untouched.[6]
- 0% de-novo SUI across all reported series.[2][3]
Limitations
- Limited visualization — meatal / transurethral access is narrower than open vaginal exposure.
- Graft support depends on the native periurethral bed alone; theoretically less robust than fascial-flap coverage in ventral onlay.[6]
- Limited evidence base — primarily reported by a single Indian group; the only RCT is single-institution with a small sample.[2]
- Best suited for distal strictures — Nikolavsky transurethral variant is specifically for fossa-navicularis / distal disease; more proximal strictures may be technically demanding.[5]
- Not yet widely adopted — most centers worldwide still use dorsal or ventral onlay; multicenter validation is pending.
Complications
- De-novo SUI — 0% across all reported VI series.[2][3]
- Stricture recurrence — 5–15% depending on follow-up window; most failures within 2 yr.[3]
- Spraying — not reported.
- Dyspareunia — not reported (vaginal wall spared).
- Donor-site morbidity — minimal (transient cheek discomfort).
- Nikolavsky 44-pt series — 0% peri-operative or postoperative complications.[5]
Comparison of the Three Ventral Approaches
| Feature | Ventral Inlay (VIBMGU) | Ventral Onlay (VOBMGU) | Ventral Vaginal Flap |
|---|---|---|---|
| Vaginal wall incision | No | Yes | Yes |
| Fascial flap creation | No | Yes | No (pedicled flap) |
| Graft support | Native periurethral bed | Periurethral fascial flaps | Own vascular pedicle |
| OR time | Shortest (~ 30 min) | Moderate (~ 64–98 min) | variable |
| Blood loss | Least (~ 10 mL) | Low (~ 10–20 mL) | variable |
| Catheter | 1 wk (transurethral) – 3 wk | ~ 3 wk | ~ 3 wk |
| Same-day discharge | Yes (transurethral) | No | No |
| Reported success | 85–95% | 86–98% | 57–100% |
| De-novo SUI | 0% | 0–4.5% | 0% |
| Best for | Distal / mid; vaginal sparing | Any location | Distal strictures |
Guideline Position
AUA 2023 recommends urethroplasty for FUS, with success rates of 69–95% across techniques (oral mucosa grafts dorsal or ventral, vaginal flaps, or combinations) driven by surgeon experience. The ventral inlay technique is not specifically named but falls within the umbrella of ventral oral-mucosa-graft approaches.[7]
Summary
Female ventral inlay BMG urethroplasty is the most vaginal-sparing, fastest, and lowest-morbidity technique among ventral approaches, with 85–95% success including 5-year life-table durability of 85%. The Mandal 2025 RCT established non-inferiority to dorsal onlay with substantially shorter OR time and less blood loss. The Nikolavsky transurethral variant enables same-day discharge and 1-week catheterization for distal disease. Primary limitations are the single-group evidence base and preference for distal / mid strictures.[1][2][3][5]
References
1. 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.
2. Mandal S, Gaur AS, Singh K, et al. Comparative efficacy of dorsal-onlay and ventral-inlay buccal mucosal graft urethroplasty in female urethral stricture: a randomized clinical trial. Urology. 2025;200:52-58. doi:10.1016/j.urology.2025.01.064.
3. Kumaraswamy S, Mandal S, Das MK, Nayak P. Long-term follow-up and success rate of ventral inlay buccal mucosal graft urethroplasty for female urethral stricture disease. Urology. 2022;166:146-151. doi:10.1016/j.urology.2022.05.002.
4. Gülpınar Ö, Zumrutbas AE, Sancı A, et al. The outcomes of three buccal mucosal graft urethroplasty techniques in women with urethral stricture disease. Neurourol Urodyn. 2021;40(8):1921-1928. doi:10.1002/nau.24764.
5. Sterling J, Daneshvar M, Nikolavsky D. Transurethral ventral inlay buccal mucosa graft urethroplasty: technique and intermediate outcomes. BJU Int. 2023;132(1):109-111. doi:10.1111/bju.16007.
6. 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.
7. 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.