ntAAU Urethroplasty (Non-Transecting Augmented Anastomotic)
The ntAAU urethroplasty — Non-Transecting Augmented Anastomotic — is the most recently described variant of non-transecting bulbar urethroplasty, reported by Baudry, Schirmann, and Guillot-Tantay in 2025. It applies the vessel-sparing principle specifically to the traditional augmented anastomotic urethroplasty with dorsal onlay buccal graft: the obliterative segment is excised through the spongiosum without transecting it, and the remaining strictured urethra is augmented with a dorsal onlay BMG.[1]
For the broader non-transecting family, see Non-Transecting Bulbar Urethroplasty, ANTA, MsANTA / Joshi Step, and MANTA. For the transecting alternative, see Augmented Anastomotic Urethroplasty. For graft material, see Buccal Mucosa Graft.
Concept and Rationale
ntAAU and ANTA (Welk / Kodama 2012) share the same conceptual framework — non-transecting excision of an obliterative segment combined with dorsal onlay BMG augmentation. The Baudry 2025 series formally validates the approach in a contemporary cohort focused specifically on obliterative bulbar strictures >2 cm, where pure EPA cannot bridge the defect but the surgeon wishes to avoid full spongiosal transection.[1][2]
The clinical importance of avoiding spongiosal transection — the Chapman 2019 sexual-dysfunction signal,[3] the Oszczudlowski 2023 meta-analysis,[5] and the Scandinavian RCT — is housed in the umbrella Non-Transecting Bulbar Urethroplasty article. The signal most directly relevant to ntAAU is Redmond / Rourke 2020 (n = 507): transecting AAU was independently associated with stricture recurrence (HR 4.8, p = 0.002) vs pure non-transecting dorsal onlay.[4] ntAAU offers the obliterative-segment-excision option of traditional AAU without the spongiosal transection that drives that HR 4.8 signal.
Indications
- Obliterative bulbar strictures >2 cm where EPA alone cannot be performed.[1]
- The surgeon wishes to avoid full spongiosal transection to preserve sexual function.[3]
- Adequate native urethral plate exists for the dorsal onlay graft to engraft against.[1]
Contraindications / limitations
- Lichen sclerosus (use staged BMG urethroplasty)
- Strictures suitable for pure dorsal onlay BMG (where the excisional component is unnecessary)
- Strictures where the obliterative segment is too long for safe excision through a non-transected spongiosum
Surgical Technique
The technique combines the principles of non-transecting excision with dorsal onlay buccal graft augmentation.[1]
Step 1 — Approach. Bulbar urethra exposed via a perineal midline incision. The corpus spongiosum is mobilized but not transected.
Step 2 — Mucosectomy of the obliterative segment. The obliterative segment is excised through the spongiosum (similar to ANTA), removing the fibrotic mucosal core while the outer spongy tissue remains in continuity.
Step 3 — Mucosal anastomosis at the obliterative core. The healthy mucosal edges at the site of excision are spatulated and anastomosed in a tension-free, mucosa-to-mucosa fashion — the "anastomotic" component.
Step 4 — Dorsal onlay BMG augmentation. A buccal mucosal graft is placed as a dorsal onlay to augment the remaining strictured urethra — the "augmentation" component. The graft is sutured to the urethral plate edges and quilted to the underlying tunica albuginea of the corpora cavernosa.
Step 5 — Closure. The corpus spongiosum is closed over the reconstructed urethra (spongioplasty); bulbospongiosus and perineal tissues approximated. 16–18 Fr urethral catheter for 2–3 weeks.
The spongiosum remains in continuity throughout — preserving the bulbar arteries and the dorsal vascular supply to the urethral mucosa.[1][6]
Outcomes — Baudry 2025
The Baudry / Schirmann / Guillot-Tantay 2025 series:[1]
| Parameter | Result |
|---|---|
| Number of patients | 42 |
| Median follow-up | 18 months |
| Stricture inclusion criteria | Obliterative bulbar >2 cm |
| Anatomical success | 90.5% |
| Functional success (Qmax >15 mL/s) | 83.3% |
| Complication rate | 14.2% (infections, abscess, bleeding) |
| Median IIEF-5 | 22 (preserved) |
| Salvage of failures | Redo urethroplasty |
The key signal — erectile function preservation (median IIEF-5 of 22) and a 90.5% anatomical success rate for an indication that traditionally required transecting AAU.[1]
ntAAU vs. ANTA
ntAAU and ANTA are conceptually similar — both excise an obliterative segment without transecting the spongiosum and augment with dorsal onlay BMG. The differences are largely a matter of contemporary descriptive nomenclature and patient selection focus.
| Feature | ANTA[7] | ntAAU[1] |
|---|---|---|
| Year | 2012 | 2025 |
| Spongiosum | Preserved | Preserved |
| Mucosa | Excised (mucosectomy) | Excised (mucosectomy) |
| Approach | Dorsal | Dorsal |
| Graft | Dorsal onlay BMG | Dorsal onlay BMG |
| Series indication | Obliterative core within longer narrowing | Obliterative bulbar >2 cm specifically |
| Original n | 21 | 42 |
| Success | 93% (1-year follow-up) | 90.5% anatomical / 83.3% functional at 18 months |
The Baudry 2025 series provides larger contemporary outcome data for the indication that ANTA originally targeted, with explicit IIEF-5 documentation showing erectile function preservation.
ntAAU in the Non-Transecting Family
| Feature | VS-EPA / ntEPA[6] | ANTA[7] | MsANTA[8] | MANTA[9] | ntAAU[1] |
|---|---|---|---|---|---|
| Year | 2007 | 2012 | 2022 | 2023 | 2025 |
| Spongiosum | Preserved | Preserved | Preserved | Preserved | Preserved |
| Mucosa | Excised | Excised | Preserved (incised) | Dorsal scar superficially excised | Excised |
| Approach | Dorsal or ventral | Dorsal | Dorsal or ventral | Ventral | Dorsal |
| Graft | None | Dorsal onlay BMG | Onlay BMG | Ventral onlay BMG | Dorsal onlay BMG |
| Ideal stricture | Short ≤2 cm | >2 cm with obliterative core | Narrowed but viable mucosa | ≥2 cm with obliterative ≤1.5 cm | Obliterative >2 cm |
| Success | 90–98% | 93% | preliminary (small cohort) | 93% | 90.5% anatomical |
Key Takeaways
- ntAAU is the most recently described non-transecting augmented anastomotic technique — Baudry 2025.[1]
- Conceptually similar to ANTA (2012) — non-transecting excision + dorsal onlay BMG — but applied specifically to obliterative bulbar strictures >2 cm.
- 90.5% anatomical success / 83.3% functional success in 42 patients at 18-month median follow-up.[1]
- Erectile function preserved (median IIEF-5 of 22) — a key advantage over transecting AAU.
- Provides a non-transecting alternative for the obliterative-bulbar indication that traditionally required transecting AAU (Redmond / Rourke 2020 HR 4.8 recurrence signal).[4]
- Failures managed with redo urethroplasty; complication rate 14.2%.
References
- Baudry A, Schirmann A, Guillot-Tantay C, et al. Non-transecting anastomotic augmented urethroplasty with dorsal onlay buccal graft for the treatment of bulbous urethral strictures: results and complications. World J Urol. 2025;43(1):238. doi:10.1007/s00345-025-05633-1.
- Coddington N, Higgins M, Mian A, Flynn B. Non-transecting urethroplasty for bulbar urethral strictures — narrative review and treatment algorithm. J Clin Med. 2022;11(23):7033. doi:10.3390/jcm11237033.
- Chapman DW, Cotter K, Johnsen NV, et al. Nontransecting techniques reduce sexual dysfunction after anastomotic bulbar urethroplasty: results of a multi-institutional comparative analysis. J Urol. 2019;201(2):364-370. doi:10.1016/j.juro.2018.09.051.
- 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.
- Oszczudlowski M, Yepes C, Dobruch J, Martins FE. Outcomes of transecting versus non-transecting urethroplasty for bulbar urethral stricture: a meta-analysis. BJU Int. 2023;132(3):252-261. doi:10.1111/bju.16108.
- Jordan GH, Eltahawy EA, Virasoro R. The technique of vessel sparing excision and primary anastomosis for proximal bulbous urethral reconstruction. J Urol. 2007;177(5):1799-802. doi:10.1016/j.juro.2007.01.036.
- Welk BK, Kodama RT. The augmented nontransected anastomotic urethroplasty for the treatment of bulbar urethral strictures. Urology. 2012;79(4):917-21. doi:10.1016/j.urology.2011.12.008.
- Joshi P, Bandini M, Kulkarni SB. Mucosal-sparing augmented non-transected anastomotic (MsANTA) urethroplasty: a step forward in ANTA urethroplasty. BJU Int. 2022;130(1):133-136. doi:10.1111/bju.15734.
- Marks P, Dahlem R, Janisch F, et al. Mucomucosal anastomotic non-transecting augmentation (MANTA) urethroplasty: a ventral modification for obliterative strictures. BJU Int. 2023;132(4):444-451. doi:10.1111/bju.16112.