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Sliding-T Dorsal Inlay Urethroplasty

The "Sliding-T" dorsal inlay urethroplasty is a single-stage, glans-sparing technique for reconstruction of fossa navicularis strictures using a buccal mucosal graft (BMG), described by Hoare, Fersovich, Saavedra, and Rourke at the University of Alberta. It achieves a 92.4% success rate at mean follow-up 29.6 months with 96.3% patient satisfaction and excellent cosmetic and functional outcomes.[1]

For the broader Asopa dorsal-inlay principle, see Asopa Dorsal Inlay OMG. For graft material, see Buccal Mucosa Graft. For the transurethral variant, see Liquid / Minced Buccal Mucosal Graft.

The Challenge of Fossa Navicularis Strictures​

Fossa navicularis strictures are among the most technically challenging urethral strictures to reconstruct. The ideal repair must simultaneously achieve four goals:[1][2]

  1. An unobstructed urethra
  2. A slit-like meatus (cosmetically normal)
  3. Preservation of sexual function (erectile function, glans sensation)
  4. A cosmetically appealing glans (avoiding glans splitting or dehiscence)

Endoscopic treatments (dilation, meatotomy, DVIU) typically offer only temporary relief and necessitate lifelong instrumentation.[1] The AUA Urethral Stricture Disease Guideline (2023) recommends offering urethroplasty to patients with recurrent meatal or fossa navicularis strictures (Moderate Recommendation, Grade C), noting that strictures related to lichen sclerosus (LS) are more likely to be reconstructed successfully using oral mucosal grafts.[3]

Concept and Nomenclature​

The name "Sliding-T" derives from the shape of the incisions:

  • The "T" refers to the configuration of the urethrotomy — a longitudinal dorsal midline urethrotomy (vertical limb) combined with a transverse incision at the meatus (horizontal limb).
  • The "sliding" component refers to the way the BMG is slid into the dorsal urethrotomy defect as an inlay, with the meatal portion of the graft sliding into the transverse meatal incision to reconstruct the meatus.

This configuration allows the graft to simultaneously augment the strictured fossa navicularis dorsally and reconstruct the meatus, all through a glans-sparing approach that avoids splitting the glans.[1]

Surgical Technique​

The technique is a modification of the Asopa dorsal inlay principle, adapted specifically for the distal urethra and fossa navicularis.[1][5]

Step 1 — Positioning and preparation. Supine position with the penis exposed; a urethral catheter or sound is placed to identify the stricture.

Step 2 — Ventral urethrotomy. A ventral midline urethrotomy is made through the ventral urethral wall, extending through the strictured segment of the fossa navicularis. This opens the urethra ventrally, exposing the dorsal urethral plate.

Step 3 — Dorsal midline incision (vertical limb of the "T"). The dorsal urethral plate is incised in the midline longitudinally, through the full thickness of the dorsal urethral wall, down to the underlying glans tissue (tunica albuginea of the glans). This is the Asopa maneuver — creating a dorsal inlay defect without circumferential urethral mobilization. The incision extends the full length of the stricture.

Step 4 — Transverse meatal incision (horizontal limb of the "T"). At the distal end of the dorsal midline incision (at the meatus), a transverse incision is made, creating the horizontal bar of the "T". This widens the meatus and creates the characteristic T-shaped defect.

Step 5 — Buccal mucosal graft harvest. BMG is harvested from the inner cheek using standard technique, defatted, and tailored to match the dimensions of the T-shaped defect.

Step 6 — Graft placement (sliding the graft). The BMG is inlaid into the T-shaped defect — the longitudinal portion of the graft fills the dorsal midline urethrotomy, and the transverse portion reconstructs the meatus. The graft is sutured to the edges of the defect with absorbable sutures (e.g., 5-0 or 6-0 Vicryl / PDS). The graft sits on the well-vascularized glans tissue (tunica albuginea), which serves as the graft bed — analogous to how the tunica albuginea of the corpora cavernosa supports dorsal inlay grafts in the penile and bulbar urethra.

Step 7 — Ventral closure. The ventral urethrotomy is closed over a urethral catheter, re-tubularizing the urethra. The glans tissue is reapproximated over the graft.

Step 8 — Catheter placement. A urethral catheter is left in place for 2–3 weeks.

Key technical principles​

  • Glans-sparing — avoids splitting the glans (unlike the Jordan flap or glans-splitting approaches), preserving glans integrity, sensation, and cosmesis.[1][11]
  • No circumferential urethral mobilization — like the Asopa technique, the urethra is opened ventrally and the dorsal wall is incised in situ.[1][5]
  • Dorsal inlay principle — the graft is placed as an inlay (into a defect created by incising the dorsal wall) rather than as an onlay. Provides the graft with a well-vascularized bed (glans tissue / tunica albuginea), promoting graft take.[1][5]
  • T-shaped configuration — distinguishes this from a standard Asopa dorsal inlay; the transverse meatal component allows simultaneous meatal reconstruction, critical for fossa navicularis strictures that extend to or involve the meatus.[1]

Outcomes (Rourke Series)​

ParameterResult
Number of patients27
Mean age47.3 yr (range 19–71)
Mean stricture length3.2 cm ± 1.2 (range 1–4)
Stricture etiologyLichen sclerosus 70.4%; iatrogenic 18.5%; idiopathic 11.1%
Prior failed endoscopic treatment92.6%
Prior failed urethroplasty7.4%
Success rate92.4% (25/27)
Mean follow-up29.6 mo (range 12–60)
Recurrence managementBoth recurrences managed with meatotomy
90-day complications (Clavien ≥2)7.4% (2/27) — surgical site infection treated with antibiotics
De novo erectile dysfunction3.7% (1/27)
Chordee3.7% (1/27) — mild
Patient satisfaction96.3% (26/27) satisfied
[1]

The 70.4% lichen sclerosus etiology is particularly notable — LS-related strictures are associated with significantly higher recurrence rates after urethroplasty (HR 4.46 on multivariable analysis in the Rourke long-term outcomes study).[6] Despite this challenging patient population, the sliding-T achieved 92.4% success, suggesting it is well-suited for LS-related fossa navicularis strictures.[1]

Comparison with Other Fossa Navicularis Techniques​

TechniquenStricture lengthSuccessFollow-upKey features
Sliding-T dorsal inlay BMG (Rourke)[1]273.2 cm92.4%29.6 moGlans-sparing; T-shaped inlay; single-stage; high LS proportion (70%)
Transurethral dorsal inlay BMG (Vanni)[4]161.7 cm93.8%28.8 moFully transurethral; no external incision; glans-sparing; shorter strictures
Dorsal inlay BMG (Zumstein / Hamburg)[2]32—69%42 mo50% hypospadias-associated; mixed etiology; longer follow-up
Dorsal inlay oral mucosa (Wirtz / Belgium)[7]40meatal only82.5% (5-yr RFS 85%)85 moLongest follow-up; BMG superior to LMG (96% vs 65% 5-yr RFS)
Dorsal BMG onlay by subcoronal approach (Favre)[8]165.5 cm100%41.5 moSubcoronal approach; longer strictures extending into penile urethra
Meatotomy (Meeks / Barbagli)[9]73short87%61 moSimplest approach; high satisfaction; best for short uncomplicated strictures
Extended meatotomy / first-stage Johanson (Morey)[10]16complex87%52 moSalvage for complex / reoperative distal strictures
Ventral transverse island flap (Jordan)[11]5variable100%17 moClassic flap technique; requires glans splitting; small series
Ventral island flap + glanuloplasty (Armenakas / McAninch)[12]19variable94.7%42.7 moTailored approach; glans cap or wings; fasciocutaneous flap
Excision + circumferential BMG (Ehlers / Figler)[13]—severe——Glans-sparing transurethral excision; for severe / obliterative strictures
Distal one-stage hybrid (Hofer)[14]270.68 cm82.4%42.5 moNo graft / flap needed for most short strictures; 17.6% recurrence

Advantages​

  1. Glans preservation — no glans splitting required, preserving cosmesis, sensation, and vascularity.[1]
  2. Single-stage repair — avoids the morbidity and inconvenience of staged urethroplasty (2 operations separated by 6+ months with an intervening hypospadiac meatus).
  3. Simultaneous meatal reconstruction — the T-shaped configuration addresses both the fossa navicularis stricture and meatal stenosis in a single maneuver.
  4. No circumferential mobilization — preserves urethral blood supply and reduces ischemic complications.
  5. Applicable to lichen sclerosus — the 70.4% LS proportion with excellent outcomes suggests particular suitability for LS-related distal strictures, where genital skin grafts / flaps should be avoided.[1][3]
  6. Low complication rate — 7.4% Clavien ≥2; minimal sexual dysfunction (3.7% de novo ED, 3.7% mild chordee).[1]

Limitations and Considerations​

  • Single-center experience — described by only one group (Rourke, University of Alberta), 27 patients. Independent validation needed.[1]
  • Stricture length limitation — mean 3.2 cm (range 1–4 cm); may not be suitable for very long distal strictures extending significantly into the penile urethra. For longer distal strictures (>4–5 cm), a subcoronal dorsal onlay (Favre) or staged urethroplasty may be more appropriate.[8][14]
  • Recurrence at the meatus — both recurrences in the Rourke series were managed with simple meatotomy, suggesting the meatal component may be the most vulnerable point of the reconstruction.[1]
  • Comparison with staged repair — for complex LS-related strictures with extensive glanular involvement, staged urethroplasty remains the procedure of choice per expert opinion when there is significant tissue loss or circumferential disease. The one-stage sliding-T should be selected when the dorsal urethral plate and glans tissue are of sufficient quality to support graft take.[3]
  • LS recurrence risk — LS is a chronic, progressive disease; long-term follow-up beyond 5 years is needed to assess durability (HR 4.46 for late recurrence on multivariable analysis).[6]

Patient Selection​

The sliding-T dorsal inlay technique is best suited for:[1][3][4]

  • Recurrent fossa navicularis strictures that have failed endoscopic management
  • Stricture length 1–4 cm confined to the fossa navicularis ± meatus
  • Lichen sclerosus etiology (where genital skin should be avoided)
  • Patients desiring single-stage repair with glans preservation
  • Adequate dorsal urethral plate quality to support graft take (if the plate is severely diseased or absent, staged repair may be preferable)

Postoperative Management​

Standard dorsal inlay urethroplasty postoperative care:

  • Urethral catheter for 2–3 weeks
  • VCUG or trial of void prior to catheter removal
  • Follow-up cystoscopy at 3–6 months, then annually
  • For LS patients — ongoing surveillance for disease progression and topical steroid therapy for genital LS[3]

Key Takeaways​

The sliding-T dorsal inlay urethroplasty applies the Asopa dorsal-inlay principle to the fossa navicularis with a unique T-shaped incision that simultaneously addresses the stricture and the meatus. With a 92.4% success rate in a predominantly LS population, low complication rates, and high patient satisfaction, it represents a valuable addition to the reconstructive urologist's armamentarium for distal urethral strictures.[1] However, it remains a single-center experience requiring broader validation, and patient selection — particularly regarding stricture length, tissue quality, and LS severity — is critical to optimizing outcomes.

References​

  1. Hoare D, Fersovich JH, Saavedra A, Rourke KF. Single-stage reconstruction of fossa navicularis strictures using a "sliding-T" dorsal inlay urethroplasty with buccal mucosal graft. Urology. 2021;152:201-202. doi:10.1016/j.urology.2020.12.031.
  2. Zumstein V, Dahlem R, Maurer V, et al. Single-stage buccal mucosal graft urethroplasty for meatal stenoses and fossa navicularis strictures: a monocentric outcome analysis and literature review on alternative treatment options. World J Urol. 2020;38(10):2609-2620. doi:10.1007/s00345-019-03035-8.
  3. 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.
  4. Farrell MR, Campbell JG, Zhang L, Nowicki S, Vanni AJ. Transurethral reconstruction of fossa navicularis strictures with dorsal inlay buccal mucosa graft urethroplasty. World J Urol. 2022;40(6):1523-1528. doi:10.1007/s00345-022-03994-5.
  5. Aldaqadossi H, El Gamal S, El-Nadey M, et al. Dorsal onlay (Barbagli technique) versus dorsal inlay (Asopa technique) buccal mucosal graft urethroplasty for anterior urethral stricture: a prospective randomized study. Int J Urol. 2014;21(2):185-8. doi:10.1111/iju.12235.
  6. Calvo CI, Fender K, Hoy N, Rourke K. Affirming long-term outcomes after contemporary urethroplasty: the adverse impact of increasing stricture length, lichen sclerosus, radiation, and infectious strictures. J Urol. 2024;211(3):455-464. doi:10.1097/JU.0000000000003826.
  7. Wirtz M, Claeys W, Francois P, et al. Treatment of meatal strictures by dorsal inlay oral mucosa graft urethroplasty: a single-center experience. J Clin Med. 2021;10(19):4312. doi:10.3390/jcm10194312.
  8. Favre GA, Villa SG, Scherñuk J, Tobia IP, Giudice CR. Glans preservation in surgical treatment of distal urethral strictures with dorsal buccal mucosa graft onlay by subcoronal approach. Urology. 2021;152:148-152. doi:10.1016/j.urology.2020.12.014.
  9. Meeks JJ, Barbagli G, Mehdiratta N, Granieri MA, Gonzalez CM. Distal urethroplasty for isolated fossa navicularis and meatal strictures. BJU Int. 2012;109(4):616-9. doi:10.1111/j.1464-410X.2011.10248.x.
  10. Morey AF, Lin HC, DeRosa CA, Griffith BC. Fossa navicularis reconstruction: impact of stricture length on outcomes and assessment of extended meatotomy (first stage Johanson) maneuver. J Urol. 2007;177(1):184-7; discussion 187. doi:10.1016/j.juro.2006.08.062.
  11. Jordan GH. Reconstruction of the fossa navicularis. J Urol. 1987;138(1):102-4. doi:10.1016/s0022-5347(17)43006-0.
  12. Armenakas NA, Morey AF, McAninch JW. Reconstruction of resistant strictures of the fossa navicularis and meatus. J Urol. 1998;160(2):359-63.
  13. Ehlers M, Figler BD. Excision and circumferential buccal graft for severe meatus and fossa navicularis strictures. Urology. 2020;146:304. doi:10.1016/j.urology.2020.09.008.
  14. Hofer MD, Cooley LF, Elmasri A, Martins FE. Revisiting one-stage urethroplasties for distal urethral strictures. J Clin Med. 2021;10(24):5905. doi:10.3390/jcm10245905.