Midline Perineal Urethrostomy
The midline approach to perineal urethrostomy (PU) permits an intraoperative choice between a non-transecting loop reconstruction and a laterally based 7-flap that bridges a deeper urethra-to-skin distance. Morey and colleagues developed this algorithm from their original 7-flap technique. Retrospective series report favorable patency, but current evidence does not establish that it replaces or outperforms all other PU techniques.[1][2][3][14]
This page covers the midline approach and its two options. For the inverted-U flap alternative, see Blandy Perineal Urethrostomy. For graft-augmented PU — a dorsal buccal-mucosa onlay added to widen the stoma, performable through either a midline or an inverted-U incision — see Augmented Perineal Urethrostomy. For salvage of a failed PU when local perineal tissue is depleted, see Propeller Flap PU Revision.
Why Midline, and the Two Options
A midline incision provides adaptable exposure. The skin-to-urethra distance and the level of healthy proximal urethra help determine reconstruction; incision-related wound data from other urethroplasties are indirect evidence for PU.
- Loop technique — when the spatulated urethra reaches the perineal skin without tension (distal strictures, lower BMI), the dorsal urethral plate is preserved and the urethra is matured directly to the skin in a loop configuration, with no skin flap.
- 7-flap technique — when the healthy proximal urethra sits deep within the perineum (obesity, proximal transection), bringing it to the surface is impossible without tension. The 7-flap inverts the problem: a laterally based skin flap is advanced into the depth of the wound to meet the urethra, rather than mobilizing the urethra to the surface.[1][2]
The 7-flap is a laterally based skin flap tailored after urethral exposure; its length and base must preserve perfusion while allowing tension-free inset.[1]
Indications
- Complex, long-segment anterior urethral strictures (median ~ 8 cm, range 2.5–18 cm).[2]
- Failed prior urethroplasty or revision of a failed prior PU.[2][3]
- Lichen sclerosus and other adverse-etiology strictures.[3]
- Older or comorbid patients who are poor candidates for complex multi-stage urethroplasty.[4][5]
- High BMI — mean BMI 34.9 kg/m² in the 7-flap cohort vs 30.0 in the loop cohort (p = 0.01).[2]
The AUA 2023 urethral stricture guideline amendment endorses PU as a long-term treatment option, either as an alternative to urethroplasty (Conditional Recommendation) or specifically for patients at high risk for reconstruction failure (Expert Opinion).[5]
The Algorithmic Midline Approach
Both options begin with midline perineal exposure. Choose before transection: the loop technique preserves urethral continuity, whereas the original 7-flap is advanced to an amputated proximal urethral end.[1][2][14]
In the McKibben 2019 series of 62 patients:[2]
| Decision | Cohort | Mean BMI | Trigger |
|---|---|---|---|
| Loop technique | 20 (32.3%) | 30.0 kg/m² | Urethra reaches skin without tension — typically distal strictures or low BMI |
| 7-flap technique | 42 (67.7%) | 34.9 kg/m² | Long urethra-to-skin distance — obese patients or proximal transection |
Step-by-Step Technique
Positioning and exposure
- Dorsal lithotomy with Allen stirrups; perineum, genitalia, and inner thighs prepped and draped. Suprapubic catheter, if present, left in place.
- Vertical midline perineal incision from base of scrotum toward anus, centered over the bulbar urethra.[1][6]
The Lin study reported lower infection rates after midline than inverted-U incisions in a matched bulbar/posterior urethroplasty cohort; it did not directly compare loop, 7-flap and Blandy PU.[6]
Identify the outlet and choose the reconstruction
- Expose the bulbar urethra and define the stricture with the available imaging and endoscopy. Identify a patent proximal urethral segment and assess its distance from skin.
- Loop: open the urethra ventrally into healthy proximal tissue, retain dorsal continuity and its vascular attachments, and mature the opened urethral margins to skin without tension. Do not perform the transection used for the original 7-flap before selecting a loop.[2][14]
- 7-flap: when a flap is required to bridge a deeper outlet, the original technique uses a transected, spatulated proximal urethral end. Preserve adequate proximal caliber and avoid unnecessary dissection near the continence mechanism. A PU bypasses distal disease; routine excision of the entire distal strictured urethra is not part of every PU.[1][14]
- Design and elevate a laterally based perineal skin flap with its subcutaneous vascular tissue intact. Select skin without hair at the intended urethral interface, and tailor reach without twisting or tension.
- Inset the flap to the proximal urethral opening and complete skin-to-mucosa maturation, checking perfusion and a wide, unobstructed outlet.[1]
Catheter and closure
Place a catheter through the urethrostomy and close the remaining wound. EAU guidance permits catheter removal after 3–5 days for uncomplicated perineostomy; graft augmentation or wound concerns require a tailored plan.[15]
Outcomes
| Series | n | Success | Follow-up | Notable |
|---|---|---|---|---|
| French 2011 (first description)[1] | 10 (7-flap) | 90% | — | Outpatient setting, no perioperative complications |
| McKibben 2019 (algorithmic)[2] | 42 (7-flap) / 20 (loop) | 92.9% / 100% | Median 30.7 mo, pooled cohort | Median PGI-I 1.0 among 19/62 survey respondents |
| Joshi 2024 (midline PU)[3] | 103 | 95.1% | Median 61 mo at telephone survey in 49/103 respondents | 42/49 satisfied; 6/103 complications |
| Fuchs 2018 (PU overall)[4] | 77 | 94.8% | 50.7 mo | Selected retrospective reconstruction groups, not a randomized comparison |
| Klemm 2024[8] | 76 | 84% retreatment-free | 55 mo | High satisfaction; preserved continence |
Functional Outcomes and Quality of Life
- Voiding — significant Qmax and LUTS improvement.[8][9]
- Continence — generally preserved; median ICIQ-UI of 0 in the long-term Klemm cohort.[8]
- Sexual function — TURNS found stable mean sexual-function scores; Joshi reported de novo ED in 12/49 survey respondents. This is not an incidence estimate from all 103 operated men or from the Klemm cohort.[3][10]
- Satisfaction — in Joshi, 42/49 respondents were satisfied; 31/41 answering the sitting-to-void item were unbothered. Response selection limits generalization.[3]
Complications, Risk Factors, and Salvage
Complications are generally mild and self-limited (~ 5.8%).[3] The dominant failure mode is stomal stenosis (5–16% across series).[2][8]
Risk factors
- Prior radiation was associated with stenosis in the small dorsal-plate-preserving Myers cohort (OR 11.2; 95% CI 1.4–87.2). The wide interval limits risk estimation; it does not prove one reconstruction overcomes radiation injury.[7]
- Elevated BMI and older age are independent predictors in the Blandy / inverted-U literature.[11]
- Suprapubic catheter at the time of surgery marks more severe disease or prior failed interventions and predicts failure in the same series.[11]
Stenosis-salvage ladder
Options depend on stenosis length, tissue quality and patient preference; this is not a mandatory sequence:
- Single dilation — converted 4 of 7 Myers / McAninch failures to secondary success, raising overall success from 83% to 93%.[7]
- Redo PU using the 7-flap — the 7-flap can revise a failed PU from any prior technique; demonstrated in the original French 2011 series and salvaged 2 of 4 failures in Shinchi 2021.[1][9]
- BMG composite stomal repair (Kamat 2008) — a buccal mucosa graft is used to widen the stenotic segment, creating a composite skin-and-mucosa stoma. Particularly useful when lichen sclerosus / BXO threatens the skin component of the stoma.[13]
- Posterior thigh propeller flap revision — when local perineal tissue is depleted (radiated, scarred, multiply operated), a perforator-based flap brings healthy tissue from outside the zone of injury. See Propeller Flap PU Revision.[12]
- Penile skin graft composite stoma — alternative composite-stoma salvage demonstrated in 1 of 4 failures in Shinchi 2021.[9]
Graft-Augmented PU
When the dorsal urethral plate is compromised (extensive scarring, prior radiation, or lichen sclerosus) or a wider proximal opening is needed, the perineal urethrostomy can be augmented with a dorsal onlay buccal-mucosa graft at the time of creation — a modification (DeLong / Jordan) that addresses the dominant failure mode of stomal stenosis. Because it can be performed through either a midline or an inverted-U incision, it is covered on its own page: see Augmented Perineal Urethrostomy.
Loop vs 7-Flap — At a Glance
| Feature | Loop Technique | 7-Flap Technique |
|---|---|---|
| Proportion of cases (McKibben 2019) | 32.3% | 67.7% |
| Mean BMI | 30.0 kg/m² | 34.9 kg/m² |
| Indication | Short urethra-to-skin distance, distal strictures, low BMI | Long urethra-to-skin distance, proximal transection, high BMI |
| Flap design | None — urethral plate mobilized to skin | Laterally based 7-shaped perineal skin flap |
| Blood supply | Dorsal urethral plate longitudinal supply preserved | Lateral perineal pedicle |
| Success | 100% (20 / 20) | 92.9% (39 / 42) |
| Reoperative use | Limited | Can revise failed PU |
Comparison With Traditional PU Techniques
Cross-study patency ranges cannot rank midline, Blandy and Johanson reconstructions: patient selection, follow-up and failure definitions differ. A midline incision offers intraoperative flexibility, and a loop preserves urethral continuity; a 7-flap may provide reach in a deep perineum. EAU guidance recommends selecting the technique for anatomy, patient factors and experience.[2][14]
PU vs Long-Stricture Anterior Urethroplasty
The nonrandomized TURNS comparison included 39 PU and 92 long-stricture urethroplasty patients: estimated two-year failure was 14.5% (95% CI 4.8–39.1) versus 30.2% (18.3–47.3), respectively (p = 0.09). This supports discussing PU but does not establish superiority.[10] Fuchs reported PU use rising from 4.3% to 38.7% of complex reconstructions at one center between 2008 and 2017.[4] Guidelines support PU as a long-term choice based on patient goals and reconstructive risk, without requiring prior failed urethroplasty.[5][14]
Technical Pearls
- Caliber — mature a broad, tension-free opening into healthy proximal urethra; an arbitrary calibration target does not compensate for ischemia or residual proximal stenosis.[14]
- Skin selection — inspect the actual proposed flap for hair; do not assume all perineal skin is hairless.
- Outpatient feasibility — the original French 2011 series was performed entirely outpatient without perioperative complications.[1]
- Revision capability — failed PU (any technique) can be revised with the 7-flap or, in compromised local tissue, with a posterior thigh propeller flap.[12]
Videos
References
1. French D, Hudak SJ, Morey AF. The "7-flap" perineal urethrostomy. Urology. 2011;77(6):1487-1489. doi:10.1016/j.urology.2010.10.053.
2. McKibben MJ, Rozanski AT, Fuchs JS, Sundaram V, Morey AF. Versatile algorithmic midline approach to perineal urethrostomy for complex urethral strictures. World J Urol. 2019;37(7):1403-1408. doi:10.1007/s00345-018-2522-1.
3. Joshi EG, VanDyke ME, Langford BT, Franzen BP, Morey AF. Algorithmic midline approach to perineal urethrostomy is associated with long-term success and high patient satisfaction. Urology. 2024;190:133-139. doi:10.1016/j.urology.2024.03.016.
4. Fuchs JS, Shakir N, McKibben MJ, et al. Changing trends in reconstruction of complex anterior urethral strictures: from skin flap to perineal urethrostomy. Urology. 2018;122:169-173. doi:10.1016/j.urology.2018.08.009.
5. 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.
6. Lin Y, Luo D, Liao B, et al. Perineal midline vertical incision versus inverted-U incision in urethroplasty: which is better? World J Urol. 2018;36(8):1267-1274. doi:10.1007/s00345-018-2267-x.
7. Myers JB, Porten SP, McAninch JW. The outcomes of perineal urethrostomy with preservation of the dorsal urethral plate and urethral blood supply. Urology. 2011;77(5):1223-1227. doi:10.1016/j.urology.2010.10.041.
8. Klemm J, Dahlem R, Schulz RJ, et al. Perineal urethrostomy for complex urethral strictures: long-term patient-reported outcomes from a reconstructive referral center and a scoping literature review. J Urol. 2024;212(5):738-748. doi:10.1097/JU.0000000000004169.
9. Shinchi M, Horiguchi A, Ojima K, et al. Evaluation of the efficacy of perineal urethrostomy for patients with anterior urethral stricture: insights from surgical and patient-reported outcomes. World J Urol. 2021;39(12):4443-4448. doi:10.1007/s00345-021-03795-2.
10. Murphy GP, Fergus KB, Gaither TW, et al. Urinary and sexual function after perineal urethrostomy for urethral stricture disease: an analysis from the TURNS. J Urol. 2019;201(5):956-961. doi:10.1097/JU.0000000000000027.
11. Ponce de León J, Salas D, Calderón J, Montlleó M, Palou J. Analysis of prognostic factors of failure in perineal urethrostomy. World J Urol. 2023;41(4):1109-1115. doi:10.1007/s00345-023-04343-w.
12. Schulster ML, Dy GW, Vranis NM, et al. Propeller flap perineal urethrostomy revision. Urology. 2021;148:302-305. doi:10.1016/j.urology.2020.12.002.
13. Kamat N. Perineal urethrostomy stenosis repair with buccal mucosa: description of technique and report of four cases. Urology. 2008;72(5):1153-1155. doi:10.1016/j.urology.2008.06.072.
14. EAU Guidelines on Urethral Strictures: perineal urethrostomy. https://uroweb.org/guidelines/urethral-strictures/chapter/disease-management-in-males. Accessed September 12, 2026.
15. EAU Guidelines on Urethral Strictures: perioperative care. https://uroweb.org/guidelines/urethral-strictures/chapter/perioperative-care-of-urethral-surgery. Accessed September 12, 2026.