Skip to main content

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; comparative evidence is insufficient to rank PU techniques.[1][2][3][14]

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 obesity or a proximal bulbar stricture leaves a long urethra-to-skin distance, direct maturation may place the stoma under 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 approximately 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 versus 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 or specifically for patients at high risk for reconstruction failure .[5]

The Algorithmic Midline Approach​

Both options begin with midline perineal exposure. The choice is made before any 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]

DecisionCohortMean BMITrigger
Loop technique20 (32.3%)30.0 kg/m²Urethra reaches skin without tension; typically distal strictures or low BMI
7-flap technique42 (67.7%)34.9 kg/m²Long skin-to-urethra distance after exposure; obesity or proximal bulbar stricture extension may favor a flap

Step-by-Step Technique​

Positioning and exposure​

  1. Administer intraoperative antimicrobial prophylaxis according to local resistance guidance before incision.[15] Position in dorsal lithotomy with Allen stirrups; prep and drape the perineum, genitalia, and inner thighs. Leave an existing suprapubic catheter in place.
  2. Vertical midline perineal incision from base of scrotum toward anus, centered over the bulbar urethra.[1][6]

In a retrospective matched cohort of 410 bulbar or posterior urethroplasties, surgical-site infection followed the midline incision less often than the inverted-U incision (bulbar 1.9% vs 18.6%, p < 0.001; posterior 3.1% vs 16.4%, p = 0.001). A companion anatomic study found that the inverted-U incision damaged approximately 1.6 to 2.0 times as many vessels and nerves, with a similar operative field.[6]

Identify the outlet and choose the reconstruction​

  1. 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.
  2. Loop: open the urethra ventrally into healthy proximal tissue and mobilize the bulbar urethra from the corpora as needed to bring the urethrotomy to skin while preserving dorsal plate continuity and longitudinal blood flow. An inferior perineal Z-plasty can reduce tension at the skin inset. Do not transect the urethra before selecting a loop.[2][14]
  3. 7-flap: when a flap is needed to bridge a deeper outlet, assess whether the dorsal urethral plate can be retained; in McKibben's later cohort, 7/42 flap cases combined the flap with a non-transecting loop. In the original amputating technique, divide the urethra at the distal bulb, oversew the distal stump, and make a right-lateral urethrotomy into healthy proximal urethra. Distal ligation precludes later second-stage tubularization, so counsel before choosing that technique. Preserve adequate proximal caliber and avoid unnecessary dissection near the continence mechanism; a PU need not excise the entire distal strictured urethra.[1][2][14][19]
  4. Mark a squared 7 with its vertical base on the midline. After urethral exposure, tailor the right-lateral limb into a full-thickness flap that reaches the proximal urethrotomy without tension. Preserve adequate subcutaneous thickness for cutaneous perfusion, select skin without hair at the urethral interface, and rotate the flap medially without twisting.[19]
  5. Advance and rotate the flap medially and deep. Suture its tip to the right-lateral proximal urethrotomy with absorbable suture, mature the contralateral urethral edge to left perineal skin, then suture the remaining flap edges to perineal skin. Check perfusion and confirm a wide, unobstructed outlet.[1][19]

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] McKibben's postoperative protocol checks the incision, voiding, postvoid residual, and symptom score at 4–6 weeks, then offers annual symptom review.[2]

Outcomes​

SeriesnSuccessFollow-upNotable
French 2011 (first description)[1]10 (7-flap)9/10 (90%) spontaneously voiding without PU revision or proximal diversion—Outpatient setting, no perioperative complications
McKibben 2019 (algorithmic)[2][14]42 flap-assisted (35 amputating, 7 combined flap/loop) / 20 loop-only39/42 (92.9%) pooled flap-assisted / 20/20 (100%) loop-only, functional voiding without further proceduresMedian 53.6 mo (flap-assisted) / 13 mo (loop-only); 30.7 mo pooledMedian PGI-I 1.0 among 19/62 survey respondents
Joshi 2024 (midline PU)[3]10398/103 (95.1%) free from re-intervention on chart reviewTelephone survey: median 61 mo among 49/103 reached42/49 satisfied; 6/103 complications
Fuchs 2018 (PU overall)[4]7794.8% free from further operative managementMedian 50.7 mo for all 403 reconstructions (pooled)Selected retrospective reconstruction groups
Klemm 2024[8]7684% retreatment-freeMedian 55 moQuestionnaire respondents: median ICIQ-UI SF 0; high satisfaction

Functional Outcomes and Quality of Life​

  • Voiding. Qmax and LUTS scores improved significantly.[8][9]
  • Continence. Among questionnaire respondents in the long-term Klemm cohort, the median ICIQ-UI SF score was 0 (range 0–21).[8]
  • Sexual function. TURNS found no significant SHIM or MSHQ change in the small PU questionnaire subsets (13 and 17 men, respectively)[10]; Joshi reported de novo ED in 12/49 survey respondents[3].[3][10]
  • Satisfaction. In Joshi, 42/49 respondents were satisfied; 31/41 answering the sitting-to-void item were unbothered.[3]

Complications, Risk Factors, and Salvage​

In Joshi's midline cohort, postoperative complications were mild and self-limited in 6/103 men (5.8%).[3] Across PU techniques, EAU also lists wound dehiscence, scrotal abscess, urinary infection or urosepsis, bleeding, and transient scrotal pain or numbness; medium-term post-micturition dribble was reported in 22.2–30.8% where assessed.[3][14] The dominant failure mode is stomal stenosis, reported in approximately 5–18% across the cited series.[2][3][7][8] Patency falls with longer follow-up. EAU summarizes patency of 51.5–100% across retrospective, heterogeneous case series, and the Klemm series reported 90%, 83% and 71% at two, five and ten years.[14]

A separate 20-year, seven-center cohort of 299 men undergoing PU as urinary diversion after total penectomy for penile cancer — a distinct oncologic population with median follow-up of 19 months — found a 30-day postoperative complication rate of 19% (mostly minor, Clavien-Dindo I-II) and a stomal stenosis rate of 12%, with a Kaplan-Meier probability of stenosis revision at one year of 9.3%.[17]

After total penectomy, adequate urethral length must reach the perineal outlet without kinking or tension to avoid urethral necrosis, which can also follow postoperative infection. If necrosis occurs, catheter drainage and debridement of necrotic tissue are followed, when needed, by further urethral mobilization or recreation of the perineal urethrostomy.[18]

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).[7] The interval is wide (45 men, 40 with follow-up), so the estimate is imprecise.[7] Post-radiation membranous urethral specimens show higher collagen density, more hyalinized fibrosis and lower vascularity than non-irradiated specimens (p = 0.0005 for vascularity).[16]
  • Elevated BMI and older age are independent predictors in the Blandy / inverted-U literature.[11]
  • Suprapubic catheter at surgery was associated with instrumentation-defined failure in the retrospective Blandy cohort (p = 0.003).[11]

Stenosis-salvage ladder​

Options depend on stenosis length, tissue quality and patient preference:

  1. Single dilation. Converted 4 of 7 Myers / McAninch failures to secondary success, raising overall success from 83% to 93%.[7]
  2. Redo PU. French reported one 7-flap revision of an existing PU; Shinchi reported redo PU in two of four failures without specifying the revision technique.[1][9]
  3. BMG composite stomal repair (Kamat 2008). A buccal mucosa graft is used to widen the stenotic segment, creating a composite skin-and-mucosa stoma.[13]
  4. 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]
  5. Penile skin graft composite stoma. An alternative composite-stoma salvage demonstrated in 1 of 4 failures in Shinchi 2021.[9]

Graft-Augmented PU​

In selected cases with extensive scarring, prior radiation, lichen sclerosus, or an inadequate proximal opening, a dorsal onlay buccal-mucosa graft can be added at PU creation to widen the outlet, as described by DeLong and colleagues.[21][14] Whether augmentation reduces stenosis compared with a suitable skin-only PU is unknown.[14] 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 and 7-Flap Techniques Compared​

FeatureLoop Technique7-Flap Technique
Proportion of cases (McKibben 2019)[2]32.3%67.7%
Mean BMI30.0 kg/m²34.9 kg/m²
IndicationShort urethra-to-skin distance, distal strictures, low BMILong urethra-to-skin distance, proximal transection, high BMI
Flap designNone; urethral plate mobilized to skinLaterally based 7-shaped perineal skin flap
Blood supplyDorsal urethral plate longitudinal supply preservedLateral perineal pedicle
Functional voiding without further procedures[2]20/20 (100%) at median 13 mo39/42 (92.9%) at median 53.6 mo
Reoperative useLimitedCan revise failed PU

Comparison With Traditional PU Techniques​

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. McKibben's series describes selecting loop or 7-flap PU by intraoperative urethra-to-skin reach.[2] The 2026 EAU guideline gives a weak recommendation to choose PU type by surgeon experience and patient characteristics, with separate weak recommendations to consider a 7-flap for obesity or proximal bulbar/membranous stricture disease.[14]

PU vs Long-Stricture Anterior Urethroplasty​

The nonrandomized TURNS comparison included 39 PU and 92 long-stricture anterior urethroplasty patients with baseline and follow-up patient-reported outcomes: estimated two-year failure requiring reintervention was 14.5% (95% CI 4.8–39.1) versus 30.2% (18.3–47.3), respectively (p = 0.09).[10] The difference was not statistically significant.[10] A 2025 meta-analysis of six observational cohorts (624 urethroplasty and 256 PU patients) also found no statistically significant success difference (RR 0.93, 95% CI 0.84–1.03), but heterogeneity was substantial (I² = 69%).[20] Fuchs reported PU use rising from 4.3% to 38.7% of complex reconstructions at one center between 2008 and 2017.[4] AUA supports PU as a long-term choice based on patient goals and reconstructive risk, without requiring prior failed urethroplasty.[5] EAU recommends offering PU for complex anterior stricture disease and choosing the type by experience and patient characteristics .[5][14]

Technical Pearls​

  • Caliber. McKibben's operative protocol advanced to healthy proximal urethra accommodating a 28-Fr bougie-à-boule and opened the urethrotomy to at least 5 cm before skin maturation.[2] Mature a broad, tension-free opening into healthy proximal urethra.[14]
  • Skin selection. Inspect the actual proposed flap for hair.
  • Outpatient feasibility. The original French 2011 series was performed entirely outpatient without perioperative complications.[1]
  • Revision capability. A 7-flap was used to revise one failed PU in French's original series. A posterior thigh propeller flap has been described for salvage when local perineal tissue is compromised, with one reported case followed for 17 months.[1][12]

Videos​

Perineal Urethrostomy with Z-Plasty Flap
AUA Core Curriculum
Perineal Urethrostomy
Sean Elliott MD

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.

16. Hughes M, Caza T, Li G, et al. Histologic characterization of the post-radiation urethral stenosis in men treated for prostate cancer. World J Urol. 2020;38(9):2269-2277. doi:10.1007/s00345-019-03031-y.

17. de Vries HM, Chipollini J, Slongo J, et al. Outcomes of perineal urethrostomy for penile cancer: a 20-year international multicenter experience. Urol Oncol. 2021;39(8):500.e9-500.e13. doi:10.1016/j.urolonc.2021.04.023.

18. Valadon CL, Wyre H, Holzbeierlein JM. Total penectomy. In: Smith JA Jr, Dmochowski RR, Thomas JC, Preminger GM, eds. Hinman's Atlas of Urologic Surgery. 5th ed. Elsevier; 2025:1016-1018.

19. Starke NR, Simhan J, Clinton TN, et al. "'7-flap' perineal urethrostomy: an effective option for obese men with devastated urethras." Can J Urol. 2015;22(4):7902-7906. PMID:26267029

20. Zhao X, Li X, Song Y, Guo Q, Wang J. "Comparison of success rates between urethroplasty and perineal urethrostomy in the treatment of complex urethral strictures: a meta-analysis." World J Urol. 2025;43(1):327. doi:10.1007/s00345-025-05679-1

21. DeLong J, et al. "Augmented perineal urethrostomy using a dorsal buccal mucosal graft, bi-institutional study." World J Urol. 2017;35(8):1285-1290. doi:10.1007/s00345-017-2002-z