Total Anterior Scrotal Flap (Zhao Technique)
The total anterior scrotal flap (Zhao) is a single-stage axial-pattern scrotal flap that recruits the entire anterior scrotal skin — supplied simultaneously by the anterior scrotal arteries (external pudendal system) and the posterior scrotal arteries (internal pudendal / perineal system) — to provide circumferential coverage of a denuded penile shaft after penile elongation via suspensory-ligament division. It is the workhorse technique for partial penile defects with a length deficit. In the original Zhao series (n = 18, mean follow-up 2.3 y, range 1–9 y), penile length increased significantly in both flaccid and erect states (p < 0.05), 100% of patients recovered both deep and superficial sensation, and 83.3% reported satisfactory intercourse.[1]
For single-stage skin-only scrotal flaps, see Bipedicled Anterior Scrotal Flap (Fakin), Modified Bipedicle Scrotal Tunnel Flap (Murányi), and Modified Bilateral Butterfly Scrotal Flap (Yao). For staged or outpatient variants, see Pribaz / McLaughlin staged and Ventral Slit Scrotal Flap (VSSF). For the graft alternative, see Penile Skin Grafting. Full framework: Penile Reconstruction.
Rationale
The Zhao technique was developed at a Chinese center over a 15-year period (1992–2007) for partial penile defects caused by trauma (animal bite), tumor excision, or circumcision complications, where the remaining stump is too short for functional intercourse.[1] The defining innovation is combining penile elongation (suspensory ligament division) with maximal-area scrotal coverage in a single operation — addressing the length deficit and the skin deficit simultaneously.
A bilateral hemiscrotum design was insufficient in 12 / 18 patients (67%) because the combined defect (original injury + the new denuded segment created by elongation) exceeded what two hemiscrotum flaps could cover. The total anterior scrotal flap solved this by harvesting the entire anterior scrotum as a single continuous sheet.[1]
This refined the earlier Shirong technique (n = 52, 2000) — the first to combine suspensory-ligament release with scrotal-flap coverage.[2]
Vascular Anatomy — The Triple Territory
The flap exploits all three Carrera scrotal vascular territories simultaneously:[1][3]
| Source artery | System | Territory |
|---|---|---|
| Anterior scrotal arteries (terminal branches of inferior external pudendal) | External pudendal / femoral | Two lateral territories — enter at the lateral scrotal-root creases |
| Posterior scrotal arteries (branches of perineal arteries) | Internal pudendal / perineal | Central territory — enter via the posterior scrotal surface, run alongside the scrotal septum |
These three territories are widely inter-anastomosed (Carrera microvascular study, 15 cadavers). The total anterior scrotal flap incorporates the entire anastomotic network and retains bilateral anterior scrotal pedicles + the central posterior-scrotal pedicle — the most robust blood supply of any scrotal-flap technique. This likely explains the 0% flap-loss rate despite the large flap size.[1][3]
Indications
| Indication | Notes (Zhao series) |
|---|---|
| Partial penile defect with stump too short for intercourse | The prototype indication |
| Animal bite injury | Most common etiology — 9 / 18 (50%) |
| Penile tumor excision | 6 / 18 (33%) |
| Circumcision complications with significant tissue loss | 3 / 18 (17%) |
| Patient needs both elongation and skin coverage | Defining indication |
| Defect too large for bilateral hemiscrotum flaps | 12 / 18 (67%) required total flap |
Prerequisites
- Intact uninvolved anterior and posterior scrotal skin
- Intact suspensory ligament (for elongation)
- Viable corpora cavernosa and corpus spongiosum
- Functional urethra
Operative Technique
1. Penile elongation — suspensory ligament division
- Suprapubic or penoscrotal incision to expose the suspensory ligaments
- Divide the fundiform (superficial) ligament — the Scarpa's-fascia sling from linea alba
- Partial or complete division of the triangular (deep) suspensory ligament — true ligament from pubic symphysis to Buck's fascia[2][4]
- Advances the previously hidden intracorporeal portion (crura) anteriorly — average cadaveric length gain 26.4 mm (range 4–60 mm), greater in shorter pre-ligamentolysis penises (r = −0.601, p = 0.014)[4]
- V-Y advancement plasty at the dorsal penile base prevents skin traction from retracting the elongated penis[1][2][5]
2. Assess the combined defect
- Original defect + newly exposed proximal corpora after elongation
- If small enough for bilateral hemiscrotum flaps → bilateral approach (6 / 18 in Zhao)
- If exceeds bilateral capacity → total anterior scrotal flap (12 / 18 in Zhao)
3. Flap design
- Entire anterior scrotum as a single continuous sheet
- Boundaries:
- Superior: penoscrotal junction (scrotal root)
- Inferior: ~ inferior pole of the testes
- Lateral: lateral scrotal creases bilaterally
- Includes the midline raphe + skin from both hemiscrotums
- Broad-based pedicle incorporating both anterior scrotal arteries (lateral roots) + posterior scrotal arteries (central / posterior)
4. Flap elevation
- Elevate inferior → superior
- Plane above external spermatic fascia, preserving dartos with the flap
- Tunica vaginalis kept intact; testes transiently exposed
- Carefully preserve lateral pedicles (at lateral roots) and central / posterior pedicle
5. Flap rotation and wrapping
- Position the denuded shaft (including newly elongated proximal segment) centrally
- Wrap the flap as a single continuous sheet around the shaft
- Single longitudinal dorsal-midline suture line (vs the two longitudinal scars of bilateral techniques)
6. Inset
- Distal circumferential suture line to subcoronal margin / glans
- Proximal suture line to penile base / pubic skin (incorporates the V-Y closure)
- Dorsal midline longitudinal closure of flap free edges
- All interrupted absorbable suture
7. Donor closure
- Remaining posterior and inferior scrotal skin advanced anteriorly and closed primarily
- Drain if dead-space concern
- Testes re-covered by the residual scrotal envelope
8. Anti-retraction measures
- Stay suture or traction device glans-to-thigh to maintain stretch during early healing — prevents scar-mediated re-attachment of the divided suspensory ligament[2][6]
How It Differs From Other Scrotal-Flap Techniques
| Feature | Total anterior scrotal (Zhao) | Bilateral scrotal (Jeong / Yao) | Fakin bipedicled | Murányi tunnel |
|---|---|---|---|---|
| Flap composition | Entire anterior scrotum, single sheet | Two hemiscrotum flaps divided at raphe | Single midline flap with central window | Single midline flap with tunnel |
| Blood supply | Anterior + posterior scrotal (triple territory) | Anterior scrotal only (bilateral) | Bilateral anterior scrotal | Bilateral external pudendal |
| Skin surface area | Maximal | Moderate | Moderate | Moderate |
| Shaft suture lines | Single dorsal longitudinal | Dorsal + ventral longitudinal | Circumferential at base + coronal | Dorsal + ventral inverted-V |
| Combined with elongation | Yes (integral) | Not typically | No | No |
| Staging | Single | Single | Single | Single |
| Primary indication | Partial penile defect with length deficit | Circumferential skin defect (paraffinoma, trauma) | Circumferential skin defect (siliconoma) | Circumferential skin defect (paraffinoma) |
Outcomes — Zhao Series (n = 18)[1]
| Parameter | Result |
|---|---|
| Study period | 1992–2007 (15 y) |
| Etiologies | Animal bite 9, tumor excision 6, circumcision 3 |
| Bilateral scrotal flap | 6 / 18 (anterior scrotal artery only) |
| Total anterior scrotal flap | 12 / 18 (anterior + posterior scrotal arteries) |
| Combined suspensory ligament division | 18 / 18 (100%) |
| Penile length increase, flaccid + erect | Significant (p < 0.05) |
| Deep sensation recovery | 18 / 18 (100%) |
| Superficial sensation recovery | 18 / 18 (100%) |
| Erectile function retained | 18 / 18 (100%) |
| Satisfactory sexual intercourse | 15 / 18 (83.3%) |
| Flap loss | 0 / 18 |
| Mean follow-up | 2.3 y (range 1–9) — longest of any scrotal-flap series |
Comparative Context
| Outcome | Zhao total anterior (n = 18) | Fakin (n = 43) | Murányi (n = 49) | Yao (n = 7) | Mendel bilateral (n = 22) | Shirong (n = 52) |
|---|---|---|---|---|---|---|
| Flap survival | 100% | 100% | 90% success | 100% (2 minor necrosis) | 100% | All satisfactory |
| Partial necrosis | n/r | 9% | included in CD 3a | 28.6% | 0% | n/r |
| Sensation recovery | 100% deep + superficial | n/r | n/r | n/r | n/r | n/r |
| Erectile function | 100% retained | 100% erection ability | ED 6.7% | Preserved | n/r | n/r |
| Satisfactory intercourse | 83.3% | 100% | 100% | n/r | n/r | All satisfactory |
| Penile length increase | Significant (p < 0.05) | n/r | n/r | Significant (p < 0.05) | n/r | Satisfactory |
| Combined ligament division | Yes (100%) | No | No | No | No | Yes (100%) |
| Mean follow-up | 2.3 y (1–9) | 10.7 mo | n/r | n/r | n/r | n/r |
Suspensory Ligament Division — Integral Component
The elongation step is not adjunctive — it is integral to the Zhao technique.[1][2][4]
Anatomy
- Fundiform ligament — superficial Scarpa's-fascia sling from linea alba, splits around the penile root, reunites inferiorly with the scrotal septum
- Triangular (deep) suspensory ligament — true ligament from pubic symphysis to Buck's fascia on the dorsal shaft
- Together, they conceal the proximal 2–4 cm of the corpora behind the pubic bone
Length gain
- Cadaveric average 26.4 mm (range 4–60 mm)[4]
- Greater gain in shorter pre-ligamentolysis penises (r = −0.601, p = 0.014)
- Shirong n = 52 — satisfactory length in all cases[2]
- Deskoulidi n = 75 — 2–4 cm flaccid gain with V-Y plasty[8]
Risk of scar-mediated re-attachment
The dominant long-term failure mode of ligamentolysis. The Zhao technique mitigates it by:
- Interposing the scrotal-flap tissue between the penile base and pubic symphysis
- V-Y advancement plasty at the dorsal base
- Stay sutures / traction to maintain stretch during healing[1][2][5]
Advantages
- Maximal skin surface area — entire anterior scrotum as a single sheet
- Triple-territory vascular supply — most robust of any scrotal-flap technique; 0% flap loss despite large flap
- Single dorsal suture line — single continuous sheet vs the two longitudinal scars of bilateral techniques
- Combined elongation + coverage — the only scrotal-flap technique that routinely incorporates suspensory-ligament division
- Documented 100% deep + superficial sensation recovery — unique among scrotal-flap series; supported by the ilioinguinal / genitofemoral / posterior-scrotal innervation
- Longest follow-up of any scrotal-flap series (mean 2.3 y, range 1–9)
- Single-stage
- Proven across animal-bite, tumor, and circumcision etiologies
- Scrotal skin quality comparable to native shaft skin
Limitations and Disadvantages
- Large donor defect — entire anterior scrotum harvested → potential scrotal volume reduction, testicular ascension (Mendel ~ 22.7%), discomfort
- Suspensory-ligament-division risks — altered erection angle, penile instability during thrusting, scar re-attachment causing length-loss[6]
- Limited to partial penile defects — not applicable to total / near-total penile loss
- Small series (n = 18) — limited evidence base
- No standardized PROMs — predates IIEF / POSAS adoption
- Hair-bearing variability
- Late skin retraction (~ 27% class effect of scrotal flaps)[7]
- Pyramidal penile shape (~ 4.6%) from pedicle bulk at the base
- No comparison group within the Zhao publication
Within-Zhao Comparison — Total vs Bilateral
| Feature | Total anterior scrotal (n = 12) | Bilateral scrotal (n = 6) |
|---|---|---|
| Blood supply | Anterior + posterior scrotal arteries | Anterior scrotal only |
| Flap design | Single continuous sheet | Two separate hemiscrotum flaps |
| Skin surface area | Larger | Smaller |
| Defect size | Larger | Smaller |
| Shaft suture lines | Single dorsal | Dorsal + ventral |
| Donor-site morbidity | Greater (entire anterior scrotum) | Lesser |
Choice was intraoperative based on combined defect size after elongation.[1]
Relationship to Shirong (2000)
| Feature | Shirong (2000) | Zhao (2009) |
|---|---|---|
| Patients | 52 | 18 |
| Indications | Congenital short penis 39, trauma 13 | Trauma 12, tumor 6 |
| Ligament division | Superficial ± partial deep | Similar |
| Coverage | Scrotal flap OR skin graft | Scrotal flap only (bilateral or total anterior) |
| Vascular anatomy | Not specified | Explicit (anterior + posterior scrotal arteries) |
| Sensory outcomes | n/r | 100% deep + superficial recovery |
| Follow-up | n/r | Mean 2.3 y (1–9) |
| V-Y plasty | Yes | Yes |
The Zhao technique characterized the vascular anatomy explicitly, added long-term follow-up, and documented detailed functional outcomes beyond what Shirong reported.[1][2]
Patient Selection — When the Total Anterior Scrotal Flap Wins
| Choose Zhao total anterior scrotal flap | Consider alternative |
|---|---|
| Partial penile defect with length deficit needing both elongation and coverage | No length deficit (skin-only) → Fakin / Murányi / Yao |
| Large circumferential defect exceeding bilateral hemiscrotum capacity | Bilateral defect manageable with hemiscrotum flaps → Yao butterfly |
| Animal-bite injury or tumor-excision shortening | Paraffinoma / siliconoma (no length deficit) → Fakin / Murányi |
| Penile length restoration is the priority | Contaminated wound → Pribaz / McLaughlin staged[10] |
| Adequate anterior + posterior scrotal skin available | Scrotal skin insufficient / involved → STSG / FTSG or regional flap[9] |
| Long-term sensation recovery prioritized | Small ventral-only deficit → VSSF |
| Total penile loss → RFFF phalloplasty[9] |
Key Takeaways
- The only scrotal-flap technique that integrates suspensory-ligament division with coverage in a single operation — addresses length and skin deficits simultaneously
- Triple-territory blood supply (bilateral anterior scrotal + central posterior scrotal) explains the 0% flap-loss rate
- Maximal skin surface area — single continuous sheet with a single dorsal suture line
- Documented 100% deep + superficial sensation recovery at mean 2.3-y follow-up — unique among scrotal-flap series
- Trade-off: larger donor defect, ligamentolysis-related angle / re-attachment risks; preserve stretch with stay suture / V-Y plasty
- Reserved for partial penile defects with length deficit — not first-line for circumferential paraffinoma or simple skin defects
See Also
- Penile Reconstruction — full decision framework
- Bipedicled Anterior Scrotal Flap (Fakin)
- Modified Bipedicle Scrotal Tunnel Flap (Murányi)
- Modified Bilateral Butterfly Scrotal Flap (Yao)
- Staged Bipedicled Scrotal Flap (Pribaz / McLaughlin)
- Ventral Slit Scrotal Flap (VSSF)
- Penile Skin Grafting
- Suspensory-Ligament Division (cosmetic)
- Scrotal Reconstruction
References
1. Zhao YQ, Zhang J, Yu MS, Long DC. "Functional Restoration of Penis With Partial Defect by Scrotal Skin Flap." J Urol. 2009;182(5):2358–61. doi:10.1016/j.juro.2009.07.048
2. Shirong L, Xuan Z, Zhengxiang W, et al. "Modified Penis Lengthening Surgery: Review of 52 Cases." Plast Reconstr Surg. 2000;105(2):596–9. doi:10.1097/00006534-200002000-00018
3. Carrera A, Gil-Vernet A, Forcada P, et al. "Arteries of the Scrotum: A Microvascular Study and Its Application to Urethral Reconstruction With Scrotal Flaps." BJU Int. 2009;103(6):820–4. doi:10.1111/j.1464-410X.2008.08167.x
4. Ramos M, Varanda Pereira A, Silva L, Inácio AR, Álvares Furtado I. "Morphometric Predictors of Penile Length Increase After Division of Its Suspensory Ligament." Aesthetic Plast Surg. 2024;48(8):1635–1643. doi:10.1007/s00266-023-03837-7
5. Kim SW, Yoon BI, Ha US, et al. "Treatment of Paraffin-Induced Lipogranuloma of the Penis by Bipedicled Scrotal Flap With Y-V Incision." Ann Plast Surg. 2014;73(6):692–5. doi:10.1097/SAP.0b013e31828637d3
6. Shaeer O, Shaeer K, el-Sebaie A. "Minimizing the Losses in Penile Lengthening: 'V-Y Half-Skin Half-Fat Advancement Flap' and 'T-Closure' Combined With Severing the Suspensory Ligament." J Sex Med. 2006;3(1):155–60. doi:10.1111/j.1743-6109.2005.00105.x
7. Mendel L, Neuville P, Allepot K, et al. "Bilateral Pedicled Scrotal Flaps as an Alternative to Skin Graft in Penile Shaft Defects Repair." Urology. 2023;176:206–212. doi:10.1016/j.urology.2023.03.025
8. Deskoulidi PI, Caminer D. "Lengthening Phalloplasty With Division of the Suspensory Ligament and Distally Based Fat Flaps in Penis Enlargement Operations." Plast Reconstr Surg. 2023;152(3):434e–437e. doi:10.1097/PRS.0000000000010313
9. Kristinsson S, Johnson M, Ralph D. "Review of Penile Reconstructive Techniques." Int J Impot Res. 2021;33(3):243–250. doi:10.1038/s41443-020-0246-4
10. McLaughlin MM, Abbassi B, Pribaz JJ. "Bipedicled Scrotal Flap for Penile Resurfacing." Plast Reconstr Surg. 2024;153(4):935–942. doi:10.1097/PRS.0000000000010811