ANTA Urethroplasty (Augmented Non-Transected Anastomotic)
The ANTA urethroplasty — Augmented Non-Transected Anastomotic — was described by Welk and Kodama in 2012 as the first non-transecting version of augmented anastomotic urethroplasty. It applies the vessel-sparing principle to bulbar strictures that are too long for pure anastomosis but contain an obliterative core: the spongiosum is mobilized but never transected, the strictured mucosa is excised through the spongiosum (mucosectomy), the healthy mucosal edges are anastomosed, and the remaining strictured but non-obliterated segments are augmented with a dorsal onlay BMG.[1]
For the broader non-transecting family, see Non-Transecting Bulbar Urethroplasty, MsANTA / Joshi Step, MANTA, and ntAAU. For the transecting alternative, see Augmented Anastomotic Urethroplasty. For graft material, see Buccal Mucosa Graft.
Concept and Rationale
The traditional augmented anastomotic urethroplasty (AAU; Guralnick / Webster 2001) addresses bulbar strictures with a focal obliterative core within a longer narrowing: the urethra and spongiosum are completely transected, the obliterative segment is excised, and a graft bridges the remaining defect.[2] ANTA preserves the same indications but applies the non-transecting principle — the corpus spongiosum remains in continuity throughout, preserving the bulbar arteries and dorsal vascular supply.[1][3]
ANTA was the first technique to address the AAU indication without spongiosal transection. For the foundational evidence base on non-transecting urethroplasty (Chapman 2019 sexual-dysfunction signal,[4] Oszczudlowski 2023 meta-analysis,[6] Scandinavian RCT), see the umbrella article on Non-Transecting Bulbar Urethroplasty. The most ANTA-specific signal is Redmond / Rourke 2020 (n = 507), which showed that transecting augmented anastomotic urethroplasty was independently associated with stricture recurrence (HR 4.8, p = 0.002) vs pure non-transecting dorsal onlay — driving the contemporary preference for non-transecting variants whenever a graft is added to an anastomotic repair.[5]
Indications
- Bulbar strictures too long for pure anastomosis (typically >2 cm) with a dense obliterative or near-obliterative core surrounded by a longer segment of narrowing.[1]
- Patients in whom preservation of the corpus spongiosum is prioritized to reduce sexual dysfunction.[3][4]
- A useful alternative when the surgeon wishes to use a smaller graft than would be required for pure dorsal onlay over the entire strictured segment.[1]
Contraindications / limitations
- Obliterative segment too long for safe excision through a non-transected spongiosum
- Lichen sclerosus
- Strictures suitable for pure dorsal onlay BMG (where the excisional component is unnecessary)
Surgical Technique
Step 1 — Approach. Bulbar urethra exposed via a perineal midline incision. The corpus spongiosum is mobilized but not transected.
Step 2 — Mucosectomy of the strictured segment. The strictured urethral mucosa is excised through the spongiosum — the fibrotic mucosal segment is removed while the outer spongy tissue and its vasculature remain 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 of the technique.
Step 4 — Dorsal onlay BMG augmentation. A buccal mucosal graft is then placed as a dorsal onlay to augment the remaining narrowed but non-obliterated segments of the 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 result is reconstruction of the bulbar urethra without spongiosal transection — the spongy tissue and its bulbar artery supply remain in continuity throughout the repair.[1]
Distinction from Transecting AAU
| Feature | Transecting AAU[2] | ANTA[1] |
|---|---|---|
| Spongiosum | Completely transected | Preserved (in continuity) |
| Bulbar arteries | Disrupted | Preserved |
| Obliterative segment | Excised | Excised (mucosectomy through spongiosum) |
| Anastomosis | Spatulated end-to-end (full thickness) | Mucosa-to-mucosa only |
| Graft | Onlay over the anastomotic site | Dorsal onlay over remaining narrowed segments |
| Recurrence (Redmond 2020) | HR 4.8 vs pure dorsal onlay[5] | Comparable to dorsal onlay[1] |
Outcomes — Welk / Kodama 2012
The original Welk / Kodama 2012 series compared 21 ANTA patients with 23 dorsal onlay patients:[1]
| Parameter | ANTA | Dorsal onlay |
|---|---|---|
| n | 21 | 23 |
| Success rate | 93% | comparable, NS |
| Median buccal graft length | 4.5 cm | 5.0 cm (p = 0.047) |
| Operative time | shorter | longer |
The key practical advantage was a significantly smaller buccal graft — reducing oral donor-site morbidity — while achieving equivalent success.[1]
Caveat — the AAU recurrence signal
Redmond / Rourke 2020 (n = 507) found that augmented anastomotic urethroplasty as a category (including both transecting and non-transecting variants) was independently associated with higher recurrence compared to pure dorsal onlay BMG for long bulbar strictures (HR 4.8, p = 0.002), suggesting that the excisional component itself may be a risk factor rather than purely the transection.[5] This finding has driven a shift toward pure non-transecting dorsal onlay as the preferred default for long bulbar strictures, with ANTA reserved for the specific scenario of an obliterative core where dorsal onlay alone is unlikely to bridge the defect.
ANTA in the Non-Transecting Family
| Feature | VS-EPA / ntEPA[3] | ANTA[1] | MsANTA[7] | MANTA[8] | ntAAU[9] |
|---|---|---|---|---|---|
| Year | 2007 | 2012 | 2022 | 2023 | 2025 |
| Spongiosum | Preserved | Preserved | Preserved | Preserved | Preserved |
| Mucosa | Excised | Excised (mucosectomy) | 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% |
ANTA was the first non-transecting augmented anastomotic technique and established the conceptual framework that MsANTA, MANTA, and ntAAU subsequently refined.
Key Takeaways
- ANTA was the first non-transecting AAU — described by Welk and Kodama in 2012.[1]
- The corpus spongiosum is mobilized but never transected; the strictured mucosa is excised through the preserved spongiosum.
- Dorsal onlay BMG augments the remaining narrowed segments, with a smaller graft than would be needed for pure dorsal onlay (4.5 vs 5.0 cm, p = 0.047).[1]
- 93% success in the original 21-patient series.
- The Redmond / Rourke 2020 HR 4.8 recurrence signal applies to AAU as a category; pure dorsal onlay remains the preferred default for long bulbar strictures without an obliterative core, while ANTA / ntAAU / MANTA target strictures with an obliterative core.[5]
- ANTA established the conceptual framework for the entire non-transecting augmented family (MsANTA 2022, MANTA 2023, ntAAU 2025).
Videos
References
- 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.
- Guralnick ML, Webster GD. The augmented anastomotic urethroplasty: indications and outcome in 29 patients. J Urol. 2001;165(5):1496-501.
- 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.
- 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.
- 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.
- 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.