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Kulkarni One-Stage Panurethral Urethroplasty

Kulkarni's one-stage panurethral urethroplasty is a single-stage reconstruction for long-segment and panurethral anterior urethral strictures using one-sided urethral dissection, penile invagination through a perineal approach, and dorsal or dorsolateral oral mucosa graft (OMG) onlay. Developed by Sanjay Kulkarni and colleagues in India with the original series dating to 1998,[1][2] the technique solves the central challenge of panurethral disease — accessing the entire urethra from meatus to bulb without a separate penile incision — by delivering the penile shaft into the perineal wound and preserving contralateral neurovascular supply through a one-sided dissection strategy.

Indications​

  • Panurethral strictures involving both the penile and bulbar urethra, typically ≥ 8–10 cm in length[1][3]
  • Complex anterior peno-bulbar strictures[4]
  • Most common etiologies: lichen sclerosus (especially in South Asia) and iatrogenic causes (instrumentation, catheterization, prior failed repairs)[1][2]
  • Primary and redo settings — success is lower for redo cases (86.5% vs. 61.5%)[1]
  • Pediatric long-segment non-hypospadias strictures[5]

Surgical Technique​

The key innovation is one-sided urethral dissection combined with penile invagination — together these allow the surgeon to open and graft the entire anterior urethra through a single perineal incision while preserving the contralateral blood supply and dorsal nerve of the penis.[1][2][6]

Step-by-Step​

1. Positioning and incision

Lithotomy position. Midline perineal incision to expose the bulbar urethra. (This is the standard access; the penoscrotal, distal-shaft, and circumcoronal-degloving alternatives are compared under Incisions and Access Options below.)

2. One-sided urethral mobilization

The urethra is mobilized from the corpora cavernosa on one side only (typically the left), preserving the contralateral lateral urethral blood supply and the central perineal tendon attachments. This is the critical distinction from the Barbagli dorsal onlay, which requires circumferential mobilization — the one-sided approach prevents the devascularization responsible for graft-bed failure across the full penile segment.[1][7][2]

3. Penile invagination

The penile shaft is invaginated retrogradely through the perineal incision, delivering the penile urethra into the operative field. This single maneuver brings the entire anterior urethra — from the external meatus to the bulbomembranous junction — into the perineal wound, eliminating the need for a separate penile or penoscrotal incision.[4][3][1]

4. Dorsal urethrotomy

The urethra is opened along its dorsolateral aspect on the side of dissection through the entire strictured segment.

5. Graft harvest and placement

One or two OMGs (buccal or lingual) are harvested and placed as a dorsal onlay on the opened urethral plate. The graft is sutured to the tunica albuginea on one side and to the urethral plate on the other, using the underlying corpora cavernosa as the vascular bed. For true panurethral strictures requiring coverage > 15–20 cm, two grafts are typically needed — one from each cheek or one buccal + one lingual. Penile skin grafts have been reported as an alternative when oral mucosa is insufficient.[1][2][4]

6. Closure

The urethra is closed over a urethral catheter and a suprapubic catheter. The penis is reduced to its anatomic position and the perineal wound closed in layers.

Incisions and Access Options​

The defining advantage of the Kulkarni family is that the penile urethra can be reconstructed without a penile skin incision — the degloving morbidity of the traditional approach (skin-flap necrosis, lymphedema, altered sensation) is avoided by delivering the penis into a more proximal wound and applying the one-sided dorsal onlay from there.[15][12] The same one-sided principle can be delivered through several incisions; the choice is driven chiefly by stricture location.

AccessRoute to the urethraBest suited for
Circumcoronal deglovingSubcoronal incision ~0.5 cm below the corona; deglove along Buck's fasciaIsolated penile strictures; when penile delivery into a proximal wound is difficult
Perineal + penile invagination (standard Kulkarni)Midline perineal incision; penis invaginated retrogradely into the woundPanurethral / peno-bulbar strictures — the whole anterior urethra through one incision
Penoscrotal + penile inversionPenoscrotal incision; penis inverted into the wound (supine)Penile-urethral strictures; no penile incision; supine positioning
"Mini-Kulkarni" (distal-shaft, glans-sparing)Longitudinal distal penile-shaft incision over the prepuce; distal urethra rotated laterallyIsolated fossa-navicularis / meatal strictures

Circumcoronal degloving — the traditional penile approach​

Classic access to the penile urethra is a circumferential subcoronal incision ~0.5 cm below the corona, degloving the penis along Buck's fascia.[15] It gives direct exposure but carries the degloving-specific morbidity the invagination and inversion approaches were designed to avoid; it remains reasonable for isolated penile strictures or when delivering the penis into a proximal wound is difficult.

Penoscrotal inversion (Warner)​

Warner and colleagues described penile inversion through a penoscrotal incision — a one-sided anterior dorsal oral-mucosa graft urethroplasty performed by inverting the penis into a penoscrotal wound. Like the perineal Kulkarni it requires no penile skin incision, and it adds the practical advantages of a single-stage repair in the supine position rather than lithotomy.[12] In the initial series of 5 patients (mean stricture 3 cm; etiologies instrumentation, lichen sclerosus, and failed hypospadias), 4 / 5 (80%) were successful. A midline penoscrotal incision has likewise been used to reach the penile urethra for a dorsal onlay that uses the tunica albuginea itself as the augmentation tissue (Mathur — 94.9% initial success in 79 patients), illustrating the versatility of penoscrotal access.[14]

The "Mini-Kulkarni" — distal / fossa-navicularis application​

The "Mini-Kulkarni" miniaturizes the one-sided dissection plus dorsal-onlay principle for isolated fossa-navicularis and meatal strictures, glans-sparing. Through a longitudinal incision in the distal third of the penile shaft over the prepuce, the distal urethra is rotated laterally and a dorsal buccal-mucosa graft is laid against the glanular bed — preserving the contralateral blood and nerve supply and avoiding glans-splitting.[13] In the initial report (6 patients), mean Qmax rose from 7.8 to 15.2 mL/s at 6 months, with one urinary-spray complaint and one recurrence, and no fistula or glans dehiscence.[13]

Evidence caveat: the Mini-Kulkarni is described in a 2025 preprint (n = 6, 6-month follow-up, not yet peer-reviewed) and is presented here as an emerging glans-sparing option, not an established standard. For better-validated distal techniques, see the dorsal-inlay and meatal approaches — Asopa dorsal inlay and meatotomy / meatoplasty.

Comparison with Barbagli Dorsal Onlay​

Kartal et al. compared one-sided dorsolateral onlay (Kulkarni) vs. standard circumferential dorsal onlay (Barbagli) in 65 patients with long anterior strictures (mean 14 cm):[7]

ParameterKulkarni One-SidedBarbagli Dorsal Onlay
Operative time180 min196 min (p = 0.037)
Estimated blood loss164 mL202 mL (p = 0.033)
Hospital stay3.5 days4.4 days (p = 0.002)
Perioperative complications16.1%37.8% (p = 0.046)
Success rate (~5 yr)87.1%70.3%

The advantages of one-sided dissection are attributed to reduced devascularization of the urethral plate and preservation of the contralateral nerve supply.

Outcomes​

Across multiple series, stricture-free rates are consistently in the 85%–90% range for primary repair:[1][7][8][4]

SeriesnStricture LengthFollow-upSuccess
Kulkarni 2012[1]—Panurethral—86.5% (primary); 61.5% (redo)
Kartal 2020[7]31Mean 14 cm~5 yr87.1%
Zumrutbas 2020[8]68Panurethral24 mo87.9% (primary); 83.8% (all)
Takekawa 2025[4]47Complex anterior~3 yr87.2%

Most recurrent strictures develop at the proximal graft margin (bulbar end).[1] Recurrence is significantly higher in patients older than 65 years (35.7% vs. 4.8% in those ≤ 65).[8]

Functional and Patient-Reported Outcomes​

  • Voiding function: Significant improvement in Qmax (mean postoperative ~25 mL/s) and IPSS (from 23 to 10, p < 0.001)[8][3]
  • Erectile function: SHIM scores unchanged postoperatively — a major advantage of one-sided dissection preserving the dorsal nerve of the penis[4][3]
  • Ejaculatory function: Improved after surgery (MSHQ scores from 8 to 11, p = 0.004)[3]
  • Patient satisfaction: 88.6% satisfied; 94.3% would choose the procedure again[8]

Complications​

ComplicationRate
Post-void dribblingUp to 45% — most common complaint[3]
Transient penile chordee~25%, typically resolves spontaneously[3]
Donor-site complications~5%, mostly Clavien-Dindo grade 2[4]
Stricture recurrence10%–17%; managed with dilation, DVIU, meatoplasty, or re-urethroplasty[8][1]

Guideline Context​

The AUA 2023 Urethral Stricture Guideline Amendment states that surgeons may reconstruct long multi-segment strictures with one-stage or multi-stage techniques using oral mucosal grafts, penile fasciocutaneous flaps, or a combination (Moderate Recommendation; Grade C). Oral mucosa is the first-choice graft material (Expert Opinion), and buccal and lingual mucosal grafts are equivalent alternatives (Strong Recommendation; Grade A).[9] The guideline also notes that complex panurethral reconstruction should be performed at established high-volume reconstructive centers.[9]

Relative Contraindications and Limitations​

  • Extensive lichen sclerosus with full-thickness circumferential involvement: Higher recurrence rates with one-stage repair (~18% at ≥ 24 months)[10][11] — staged BMG urethroplasty (Johanson) preferred when the urethral plate is fully obliterated by LS
  • Prior failed urethroplasty: 61.5% success vs. 86.5% for primary repair[1]
  • Age > 65 years: Significantly higher recurrence (35.7% vs. 4.8%)[8]
  • Significant medical comorbidities precluding extended operative time: Perineal urethrostomy is a legitimate long-term alternative[9]

See Also​

Videos​

One-Sided (Kulkarni) Urethroplasty
Operative video (2020)
Kulkarni Urethroplasty for Panurethral Stricture (Part 1)
Divakar Dalela (2023)

References​

1. Kulkarni SB, Joshi PM, Venkatesan K. Management of Panurethral Stricture Disease in India. J Urol. 2012;188(3):824–30. doi:10.1016/j.juro.2012.05.020

2. Kulkarni S, Kulkarni J, Surana S, Joshi PM. Management of Panurethral Stricture. Urol Clin North Am. 2017;44(1):67–75. doi:10.1016/j.ucl.2016.08.011

3. Spencer J, Blakely S, Daugherty M, et al. Clinical and Patient-Reported Outcomes of 1-Sided Anterior Urethroplasty for Long-Segment or Panurethral Strictures. Urology. 2018;111:208–213. doi:10.1016/j.urology.2017.08.029

4. Takekawa K, Horiguchi A, Shinchi M, et al. One-Sided Dorsal Onlay Urethroplasty With Penile Invagination (Kulkarni Urethroplasty) for Complex Anterior Urethral Strictures: A Single-Center Experience. Int J Urol. 2025;32(6):749–755. doi:10.1111/iju.70048

5. Patil N, Javali T. Paediatric Buccal Mucosal Graft Urethroplasty for Non-Hypospadias Urethral Strictures: A Single Centre Experience With Long Term Outcomes. Urology. 2021;158:174–179. doi:10.1016/j.urology.2021.06.029

6. Horiguchi A. Substitution Urethroplasty Using Oral Mucosa Graft for Male Anterior Urethral Stricture Disease: Current Topics and Reviews. Int J Urol. 2017;24(7):493–503. doi:10.1111/iju.13356

7. Kartal I, Çimen S, Kokurcan A, et al. Comparison Between Dorsal Onlay and One-Sided Dorsolateral Onlay Buccal Mucosal Graft Urethroplasty in Long Anterior Urethral Strictures. Int J Urol. 2020;27(9):719–724. doi:10.1111/iju.14286

8. Zumrutbas AE, Ozlulerden Y, Celen S, Kucuker K, Aybek Z. The Outcomes of Kulkarni's One-Stage Oral Mucosa Graft Urethroplasty in Patients With Panurethral Stricture: A Single Centre Experience. World J Urol. 2020;38(1):175–181. doi:10.1007/s00345-019-02758-y

9. 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

10. 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

11. Kurtzman JT, Blum R, Brandes SB. One-Stage Buccal Mucosal Graft Urethroplasty for Lichen Sclerosus-Related Urethral Stricture Disease: A Systematic Review and Pooled Proportional Meta-Analysis. J Urol. 2021;206(4):840–853. doi:10.1097/JU.0000000000001870

12. Warner JN, Tracey JM, Zhumkhawala AA, Chan KG, Lau CS. Penile Inversion Through a Penoscrotal Incision for the Treatment of Penile Urethral Strictures. Investig Clin Urol. 2016;57(2):135–140. doi:10.4111/icu.2016.57.2.135

13. Oliveira DEG, Geminiani JJ, Alvim RG, Reis AB. The "Mini-Kulkarni": A Promising New Technique for the Treatment of Strictures of the Fossa Navicularis and Urethral Meatus. Research Square [Preprint]. 2025. doi:10.21203/rs.3.rs-6805479/v1

14. Mathur RK, Himanshu A, Sudarshan O. Technique of Anterior Urethra Urethroplasty Using Tunica Albuginea of Corpora Cavernosa. Int J Urol. 2007;14(3):209–213. doi:10.1111/j.1442-2042.2007.01683.x

15. Verla W, Oosterlinck W, Spinoit AF, Waterloos M. A Comprehensive Review Emphasizing Anatomy, Etiology, Diagnosis, and Treatment of Male Urethral Stricture Disease. Biomed Res Int. 2019;2019:9046430. doi:10.1155/2019/9046430