Skip to main content

Augmented Anastomotic Urethroplasty

Augmented anastomotic urethroplasty (AAU) is a hybrid technique that combines excision of the most fibrotic / obliterative segment of a stricture with an onlay graft to reconstruct longer bulbar urethral strictures that are too long for simple excision and primary anastomosis (EPA) alone. Originally described by Guralnick and Webster in 2001, it achieves success rates of 90–97% depending on series and technique, though recent large-scale data suggest the transecting variant may be independently associated with higher recurrence than pure non-transecting dorsal onlay.[1][2][3]

For the buccal graft itself, see Buccal Mucosa Graft. For vessel-sparing variants, see Non-Transecting Bulbar Urethroplasty and Jordan Vessel-Sparing EPA.

Definition and Concept​

The core principle of AAU is to address strictures that contain a focal segment of dense fibrosis or obliteration within a longer area of narrowing. Rather than excising the entire stricture (excessive tension) or relying solely on a graft over heavily scarred tissue (poor graft take), AAU excises the worst 1–2 cm segment, performs a partial anastomosis (roof or floor strip), and augments the remaining defect with an onlay graft.[1][4]

As Guralnick and Webster originally described it: a short bulbar stricture ≤1 cm is best managed by EPA, but when total stricture length is too great for excision and anastomosis, the surgeon can perform "stricture excision with roof or floor strip anastomosis augmented by an onlay."[1]

Indications​

  • Bulbar urethral strictures >2 cm with a focal obliterative or densely fibrotic segment not amenable to EPA alone[1][6]
  • Strictures where the obliterative segment is 1–2 cm within a longer area of narrowing (total length typically 2–5+ cm)[1][6]
  • Recurrent strictures after prior endoscopic treatment or urethroplasty[4]
  • Strictures where a pure onlay graft would otherwise be placed over heavily scarred, poorly vascularized tissue (the anastomotic component removes that segment)[4]
  • The AUA Urethral Stricture Disease Guideline (2023) recommends urethroplasty as initial treatment for bulbar strictures ≥2 cm, with substitution or augmentation of the narrowed segment[7]

Surgical Technique​

Two main configurations exist, defined by which urethral wall is preserved for the anastomosis and which side receives the graft.

Configuration 1 — Floor Strip (Dorsal) Anastomosis + Ventral Onlay​

  1. The strictured segment is exposed via a perineal approach.
  2. The corpus spongiosum is fully transected through the most fibrotic segment.
  3. The most diseased portion is excised.
  4. The dorsal (floor) urethral plate is preserved and anastomosed end-to-end, creating a "floor strip" anastomosis.
  5. This leaves an oval ventral defect that is augmented with an onlay graft (buccal mucosa or pedicled skin flap).
  6. The graft is sutured to the edges of the ventral defect.[1][6]

Configuration 2 — Roof Strip (Ventral) Anastomosis + Dorsal Onlay​

  1. Same exposure and excision of the most fibrotic segment.
  2. The ventral (roof) urethral wall is preserved and anastomosed.
  3. The resulting dorsal defect is augmented with a dorsal onlay graft (typically buccal mucosa placed on the tunica albuginea of the corpora cavernosa, per the Barbagli technique).
  4. This configuration is more commonly used in contemporary practice.[1][3]

In the original Guralnick / Webster series, 20 of 29 patients received a floor strip anastomosis with dorsal onlay, and 9 received a roof strip anastomosis with ventral onlay. Mean excised length was 1.2 cm and mean onlay length was 4.5 cm.[1]

The Augmented Russell Technique (El-Kassaby)​

A specific variant in 234 patients with long bulbar strictures (mean 4.2 cm): excision of most of the diseased segment (mean 2.8 cm) with dorsal strip anastomosis, augmented by a ventral buccal mucosal patch (mean 4.7 cm). Success rate was 93.7% at mean 36 months.[6]

Key Outcomes by Series​

StudynTechniqueMean Stricture LengthSuccessFollow-up
Guralnick / Webster 2001[1]29Transecting AAU (dorsal or ventral onlay)1.5 cm (RUG)93%28 mo
Abouassaly / Angermeier 2007[4]69Transecting AAU—90%34 mo
El-Kassaby 2008[6]234Augmented Russell (dorsal strip + ventral BMG)4.2 cm93.7%36 mo
Hoy / Rourke 2013[3]163Dorsal onlay augmented anastomotic + BMGlong segment96.9%31 mo
Welk / Kodama 2012 (ANTA)[8]21Non-transecting ANTA + BMG—93%2.3 yr
Redmond / Rourke 2020[2]221 (AAU) vs 286 (DO)Transecting AAU vs non-transecting DO4.4 cm93.9% overall78.9 mo
Baudry 2025 (ntAAU)[5]42Non-transecting AAU + dorsal BMGobliterative >2 cm90.5% anatomical18 mo
Marks 2023 (MANTA)[9]54Ventral non-transecting + dorsal mucomucosal anastomosis≥2 cm (obliterative ≤1.5 cm)93% functional41 mo

The Critical Controversy — AAU vs. Pure Dorsal Onlay​

The landmark study by Redmond and Rourke (2020) — the largest comparative analysis to date (507 patients, mean follow-up 78.9 months) — fundamentally challenged the role of transecting AAU:[2]

  • Transecting AAU was independently associated with stricture recurrence on multivariate analysis (HR 4.8, p = 0.002)
  • Other independent predictors of failure: increasing stricture length (HR 1.2, p = 0.002) and iatrogenic etiology (HR 3.2, p = 0.03)
  • No difference in Clavien ≥2 complications (3.6% vs 4.2%, p = 0.74) or de novo ED (5.9% vs 5.6%, p = 0.89)
  • The institution shifted from routinely performing transecting AAU to non-transecting dorsal onlay around 2011, reflecting the evolving evidence

For longer strictures requiring grafts, a pure non-transecting dorsal onlay (without transection and anastomosis) may therefore be superior to traditional transecting AAU.

Complications​

ComplicationTransecting AAUNon-Transecting Dorsal OnlayReferences
Stricture recurrence6–10%3–7%[1][2][3]
De novo erectile dysfunction3.1–5.9%5.6%[2][11]
Postvoid dribbling40–45%28–42%[1][6][10]
Pseudodiverticulum2/29 (6.9%)rare[1]
Penile shortening (subjective)5/29 (17.2%)less common[1]
UTI3.2–3.7%3.7%[2][4]
Orchalgia—10.4%[3]
Donor site morbidity4.3%4.3%[3]
Clavien ≥23.6%4.2%[2]

Postvoid dribbling is the most common complication across all augmented techniques (28–45%), significantly more common than after simple EPA (~8%).[1][6][10]

Erectile dysfunction after AAU appears to be largely transient. Erickson et al. prospectively found that 38% of patients undergoing anterior urethroplasty developed postoperative ED, but 90% (18/20) recovered fully at a mean of 190 days. Within the bulbar urethra, EPA had slightly higher ED rates than augmented anastomotic repairs (50% vs 26%, p = 0.16), though this was not statistically significant.[11]

Evolution — Non-Transecting Augmented Techniques​

Recognition that transecting AAU may be inferior to non-transecting approaches has driven several vessel-sparing augmented modifications.

1. ANTA (Augmented Non-Transected Anastomotic) — Welk / Kodama 2012. The first non-transecting augmented technique. Complete stricture excision (mucosectomy) without transecting the spongiosum, combined with dorsal onlay BMG. In 21 patients, success was 93% — comparable to dorsal onlay BMG alone — with the advantage of using a smaller buccal graft (4.5 cm vs 5.0 cm, p = 0.047).[8]

2. MsANTA (Mucosal-Sparing ANTA) — Kulkarni 2022. A refinement where the native urethral mucosa is neither transected nor resected but reconstructed with a direct mucosa-to-mucosa anastomosis, preserving the communicant vessels from the corpus spongiosum to the urethral mucosa.[12]

3. MANTA (Mucomucosal Anastomotic Non-Transecting Augmentation) — Marks 2023. A ventral approach for strictures ≥2 cm with an obliterative segment ≤1.5 cm. The scar is superficially excised dorsally while the spongiosum is left intact. Dorsal mucomucosal anastomosis is complemented by a ventral onlay graft. In 54 patients at median 41 months: 93% functional success, no change in erectile function (IIEF-EF 27 → 24, p ≥ 0.4), and 100% patient satisfaction.[9]

4. ntAAU (Non-Transecting Augmented Anastomotic) — Baudry 2025. Non-transecting AAU with dorsal onlay BMG for obliterative bulbar strictures >2 cm. In 42 patients: 90.5% anatomical success, 83.3% functional success at median 18 months. Complication rate 14.2%. Median IIEF-5 score 22 postoperatively.[5]

Graft Placement — Dorsal vs. Ventral Onlay​

A 2025 meta-analysis of 8 studies and 655 patients comparing dorsal vs ventral onlay BMG urethroplasty found:[13]

  • Success rates — no significant difference (RR 1.00, 95% CI 0.94–1.06, p = 0.97)
  • Qmax — comparable at 3 and 12 months
  • Transient ED — significantly lower with ventral technique (RR 0.24, 95% CI 0.08–0.67, p = 0.006)
  • Permanent ED — no difference (RR 0.57, p = 0.72)

Among GURS members, dorsal graft placement is preferred (66%) over ventral (34%) for bulbar urethroplasty with BMG.[14] The dorsal onlay technique may be less dependent on surgical expertise and therefore more suitable for surgeons newer to urethroplasty.[15]

A study specifically examining proximal bulbar strictures in sexually active men found that ventral onlay had significantly better erectile outcomes: transient ED 5% vs 25% (p = 0.002) and permanent ED 1.7% vs 13.7% (p = 0.012) for ventral vs dorsal approaches.[16]

Predictors of Failure​

  • Transecting technique (HR 4.8, p = 0.002)[2]
  • Increasing stricture length (HR 1.2, p = 0.002); strictures ≥5 cm are particularly prone to recurrence (p = 0.010)[2][3]
  • Iatrogenic etiology (HR 3.2, p = 0.03)[2]
  • Older age (mean 52 vs 39 yr in failures vs successes, p = 0.02)[4]
  • Postoperative UTI (28% in failures vs 3.2% in successes, p = 0.05)[4]
  • Lichen sclerosus (50% failure with one-stage repair)[17]

Decision Algorithm — When to Use AAU vs. Other Techniques​

Stricture CharacteristicsRecommended TechniqueReferences
Short bulbar ≤2 cm, non-obliterativeEPA (transecting or non-transecting)[1][7]
Short bulbar ≤2 cm, obliterativeNon-transecting EPA (vessel-sparing)[1][7]
Long bulbar >2 cm, non-obliterativeNon-transecting dorsal onlay BMG[2][3]
Long bulbar >2 cm with focal obliterative segment ≤1.5 cmMANTA or ANTA (non-transecting augmented)[8][9]
Long bulbar >2 cm with obliterative segment >2 cmntAAU (non-transecting augmented anastomotic)[5]
Long bulbar, no obliterative segmentPure dorsal onlay BMG (preferred over transecting AAU)[2][3]
Stricture ≥5 cmDorsal onlay BMG (accept higher recurrence risk) or staged[2][7]

Key Takeaways​

  • AAU bridges the gap between EPA (short strictures) and pure onlay grafting (longer strictures) by addressing the focal obliterative component that limits graft take.
  • Traditional transecting AAU achieves 90–94% success but is independently associated with higher recurrence (HR 4.8) compared to pure non-transecting dorsal onlay in the largest comparative study.[2]
  • The field has shifted toward non-transecting augmented techniques (ANTA, MsANTA, MANTA, ntAAU) that preserve the corpus spongiosum while combining mucosectomy / anastomosis with onlay grafting, achieving 90–93% success with better vascular preservation.
  • Postvoid dribbling (28–45%) is the most common complication of all augmented techniques.
  • For longer strictures without a focal obliterative segment, a pure non-transecting dorsal onlay is now preferred over transecting AAU.
  • Strictures ≥5 cm carry higher recurrence risk regardless of technique.

Videos​

Augmented Anastomotic Urethroplasty
Operative technique

References​

  1. Guralnick ML, Webster GD. The augmented anastomotic urethroplasty: indications and outcome in 29 patients. J Urol. 2001;165(5):1496-501.
  2. 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.
  3. Hoy NY, Kinnaird A, Rourke KF. Expanded use of a dorsal onlay augmented anastomotic urethroplasty with buccal mucosa for long segment bulbar urethral strictures: analysis of outcomes and complications. Urology. 2013;81(6):1357-61. doi:10.1016/j.urology.2013.02.012.
  4. Abouassaly R, Angermeier KW. Augmented anastomotic urethroplasty. J Urol. 2007;177(6):2211-5; discussion 2215-6. doi:10.1016/j.juro.2007.01.140.
  5. 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.
  6. El-Kassaby AW, El-Zayat TM, Azazy S, Osman T. One-stage repair of long bulbar urethral strictures using augmented Russell dorsal strip anastomosis: outcome of 234 cases. Eur Urol. 2008;53(2):420-4. doi:10.1016/j.eururo.2007.06.002.
  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.
  8. 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.
  9. 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.
  10. Furr JR, Wisenbaugh ES, Gelman J. Urinary and sexual outcomes following bulbar urethroplasty — an analysis of 2 common approaches. Urology. 2019;130:162-166. doi:10.1016/j.urology.2019.02.042.
  11. Erickson BA, Granieri MA, Meeks JJ, Cashy JP, Gonzalez CM. Prospective analysis of erectile dysfunction after anterior urethroplasty: incidence and recovery of function. J Urol. 2010;183(2):657-61. doi:10.1016/j.juro.2009.10.017.
  12. 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.
  13. Hassan AA, Soliman AM, Shouman HA, et al. Dorsal- vs ventral-onlay buccal mucosal graft urethroplasty for urethral strictures: a meta-analysis. BJU Int. 2025. doi:10.1111/bju.16811.
  14. 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.
  15. Patterson JM, Chapple CR. Surgical techniques in substitution urethroplasty using buccal mucosa for the treatment of anterior urethral strictures. Eur Urol. 2008;53(6):1162-71. doi:10.1016/j.eururo.2007.10.011.
  16. Mousa A, Eissa A, Raheem AA, Zoeir A. Ventral versus dorsal onlay buccal mucosal graft urethroplasty for non-traumatic proximal bulbar urethral strictures in sexually active men: erectile and urinary functions. World J Urol. 2025;43(1):87. doi:10.1007/s00345-025-05441-7.
  17. Levine LA, Strom KH, Lux MM. Buccal mucosa graft urethroplasty for anterior urethral stricture repair: evaluation of the impact of stricture location and lichen sclerosus on surgical outcome. J Urol. 2007;178(5):2011-5. doi:10.1016/j.juro.2007.07.034.