Pedicled Anterolateral Thigh Flap Phalloplasty
Pedicled anterolateral thigh (ALT) phalloplasty creates a neophallus from lateral-thigh fasciocutaneous tissue based on the descending branch of the lateral circumflex femoral artery. Compared with RFFF phalloplasty, ALT offers a concealable donor site and avoids microvascular anastomosis, but the flap is often bulkier, urethral construction is less straightforward, and debulking / staged revision is common.[1][2][3]
This is the atlas page for gender-affirming pedicled ALT phalloplasty. For the cross-application flap anatomy and perineal / pelvic uses, see Anterolateral Thigh Flap. For cohort-level pathway selection, see Masculinizing Gender-Affirming Surgery.
Indications
ALT phalloplasty is best suited for patients who prioritize a hidden donor site, have acceptable thigh thickness, and either cannot or do not want to use the forearm donor site.[1][2]
| Patient Priority / Anatomy | Fit for Pedicled ALT |
|---|---|
| Concealed donor-site scar | Strong fit; lateral thigh scar is clothing-concealable |
| Avoid microsurgical vascular anastomosis | Strong fit for pedicled ALT |
| Forearm unavailable | Strong fit if Allen testing, prior forearm surgery, occupational needs, or scar concerns exclude RFFF |
| Thin thigh / low subcutaneous fat | Stronger fit; tube-in-tube and aesthetics are more feasible |
| High BMI / thick thigh fat | Caution; bulk, buried phallus appearance, and debulking needs increase |
| Maximal sensation and thin shaft | RFFF usually remains superior |
| Standing micturition | Possible, but usually requires staged or adjunct urethral strategy |
Contraindications and Caution Zones
ALT is forgiving vascularly but unforgiving aesthetically when the thigh is thick. Patient selection should be frank about bulk and staging.
| Scenario | Counseling Point |
|---|---|
| Thick thigh adiposity | Higher risk of bulky neophallus, difficult tube-in-tube urethra, and staged debulking |
| Standing voiding is mandatory | Discuss staged urethroplasty or adjunct flap / graft strategy rather than assuming ALT tube-in-tube |
| Need for single-stage reconstruction | ALT often needs more stages than RFFF |
| Prior thigh surgery / vascular injury | Map perforators and consider alternative flap |
| Desire for best sensory data | RFFF has stronger published sensory-outcomes evidence |
| Microsurgery unavailable but UL required | Pedicled ALT avoids vascular microsurgery, but urethral reconstruction still needs reconstructive-urology expertise |
Historical Context
Felici and Felici described free ALT phalloplasty in 2006. Pedicled ALT phalloplasty developed because the lateral-thigh flap can reach the perineum on its native pedicle, avoiding microvascular anastomosis.[4][2] Morrison et al. later described the mushroom-flap modification for glans aesthetics, and Rubino et al. reported innervated pedicled ALT phalloplasty with nerve coaptation for erogenous sensation.[5][6]
Vascular and Neural Anatomy
The pedicled ALT is based on the lateral circumflex femoral artery system, most commonly the descending branch. Perforators may be septocutaneous, musculocutaneous, or mixed, so preoperative Doppler, CTA, or careful intraoperative perforator dissection matters.[3][7][8]
| Structure | Practical Relevance |
|---|---|
| Descending branch LCFA | Dominant pedicle for most pedicled ALT phalloplasty flaps |
| Perforator variability | Musculocutaneous perforators are common; harvest may require intramuscular dissection through vastus lateralis |
| Hot zone | Perforators cluster near the midpoint of the ASIS-to-superolateral-patella line[9] |
| Lateral femoral cutaneous nerve | Main sensory nerve for pedicled ALT flap; can remain partly intact or be coapted |
| Perforator nerves | Median and superior perforator nerves may contribute to flap sensation[10] |
Technique
Flap Design and Transfer
The flap is centered over mapped perforators on the anterolateral thigh. It is harvested as a fasciocutaneous flap with the LCFA pedicle left attached, then tunneled subcutaneously toward the perineum for phallic inset.[2][3]
| Step | Technical Goal |
|---|---|
| Perforator mapping | Identify reliable perforators and plan flap dimensions |
| Skin paddle design | Balance shaft length / girth goals against donor-site closure and bulk |
| Pedicle dissection | Preserve descending-branch LCFA pedicle and avoid kinking during rotation |
| Tunnel creation | Create a generous subcutaneous tunnel to prevent compression |
| Phallic shaping | Tubularize flap as shaft-only or tube-in-tube depending on urethral plan |
| Inset | Secure phallus at pubic / perineal base; manage clitoral burial and scrotoplasty according to stage |
| Donor-site closure | Primary closure, skin graft, or pre-expanded closure depending on width / thigh circumference |
Urethral Construction Options
Urethral planning is the central ALT decision. Unlike RFFF, the ALT flap is often too thick for dependable single-flap tube-in-tube urethroplasty.[11][12]
| Urethral Strategy | Description | Tradeoff |
|---|---|---|
| Tube-in-tube ALT / mushroom flap | Inner ALT tube forms urethra, outer tube forms shaft; mushroom extension improves glans appearance | One-stage concept, but feasible mainly in thin flaps and may raise urethral risk[5] |
| Staged skin-graft urethroplasty | Stage I shaft-only ALT; Stage II ventral opening + grafted urethral plate; Stage III tubularization | More stages, but avoids forcing a bulky tube-in-tube design[12] |
| ALT shaft + RFFF urethra | Pedicled ALT for shaft and smaller RFFF for neourethra | Better urethral tissue but reintroduces microsurgery and forearm donor site[13] |
| Pedicled labia minora flap urethra | Local genital flap forms pars fixa / pendulous urethral components | Avoids forearm urethral flap; standing voiding rates vary[14] |
| RFFF inner + ALT outer | Modified free-flap tube-in-tube concept | Complex multi-flap microsurgery; useful in selected centers[15] |
Staging
ALT phalloplasty is often a longer staged project than RFFF because urethral construction and debulking are frequently separated.
| Stage | Operation | Timing / Notes |
|---|---|---|
| Stage I | Pedicled ALT transfer as shaft-only or primary tube-in-tube phalloplasty | Hysterectomy / BSO may already be complete or performed separately |
| Stage II | Vaginectomy, pars fixa urethroplasty, scrotoplasty, ventral opening of ALT, grafted urethral plate | Robinson staged approach performs this at least 6 months after transfer[12] |
| Stage III | Tubularization of grafted urethral plate | Usually at least 6 months after urethral-plate creation |
| Refinement stages | Debulking, glansplasty, testicular implants, urethral revision | Debulking is common and should be expected |
| Prosthetic stage | Erectile prosthesis | Delayed until flap and urethra mature |
Outcomes
Flap Survival and Wound Complications
Pedicled ALT has excellent flap survival, but nonurethral wound complications and dehiscence can be more common than with RFFF in some datasets.[1][16]
| Study / Review | N | Key Finding |
|---|---|---|
| Netshiongolwe 2025 SR | 769 total; 155 pedicled ALT | Pedicled ALT flap failure 0.6% vs RFFF 1.9%; satisfaction similar[1] |
| Ascha 2018 | 213; 64 ALT / 149 RFFF | ALT had higher odds of fistula, wound dehiscence, and nonurethral complications in that single-stage cohort[16] |
| Wang 2026 | 57; 10 ALT / 25 RFFF / 22 abdominal | RFFF had highest overall complications; ALT intermediate; abdominal lowest[17] |
The apparent contradictions are real. Outcomes depend heavily on whether the ALT urethra is tube-in-tube, staged skin-graft, SCIP / labia-minora assisted, or combined with a forearm urethral flap.
Standing Micturition and Urethral Outcomes
| Urethral Strategy | Key Outcome |
|---|---|
| Staged skin-graft urethroplasty | Robinson 2023 reported 87.5% standing micturition, with fistula and stricture still common[12] |
| Pedicled labia minora flap | Al-Tamimi 2020 reported 56.3% standing voiding in a small multicenter cohort[14] |
| ALT + RFFF double flap | van der Sluis 2017 reported long-term urinary complications in about half of patients, mostly strictures[13] |
| All phalloplasty techniques | Hu 2022 meta-analysis found a high pooled urethral fistula / stenosis burden across transmasculine phalloplasty[18] |
Sensation and Sexual Function
Pedicled ALT may preserve some LFCN-based sensation through the pedicle, and neurorrhaphy can be performed to the dorsal clitoral branch of the pudendal nerve. Evidence is less robust than for RFFF, but the anatomy supports sensate reconstruction.[6][10][19]
| Domain | Counseling Point |
|---|---|
| Protective sensation | May arise from preserved LFCN territory and / or nerve coaptation |
| Erogenous sensation | Requires careful nerve strategy and clitoral management |
| Orgasm | Usually depends on retained / buried clitoral complex plus cortical integration |
| Evidence quality | Sensory outcomes are heterogeneously measured; no universal coaptation standard exists[19] |
Patient-reported satisfaction can be high and similar to RFFF, but sexual-function scores are often limited before erectile prosthesis placement.[1][20][21]
Debulking and Aesthetic Revision
Debulking is one of the defining features of the pedicled ALT pathway. The need depends on thigh thickness, flap width, whether a urethra is included, and desired final girth.
| Revision Issue | Practical Point |
|---|---|
| Bulk reduction | Often staged 6-12 months after transfer once perfusion is stable |
| Buried appearance | More common in higher BMI or thick-thigh patients |
| Glansplasty / coronoplasty | Often delayed until shaft contour settles |
| Prosthesis planning | Extra soft tissue may protect prosthesis, but excessive bulk can impair cosmesis and device positioning |
| Exstrophy / deficient pubic tissue | ALT bulk can be advantageous; Harris 2021 found all surviving ALT exstrophy patients required at least one debulking procedure[22] |
Pre-expansion of the ALT donor site can improve donor-site closure and potentially thin the flap envelope, but it adds another stage and is center-specific.[23]
Erectile Prosthesis
Penetrative function usually requires delayed erectile prosthesis placement, as with RFFF. The principles are the same: delay until flap and urethra mature, wrap cylinders, and fix the device securely to pubic bone / periosteal structures.[24][25][26]
| Prosthesis Issue | Counseling Point |
|---|---|
| Timing | Usually delayed until phallus shape, sensation, wounds, and urethra are stable |
| Soft tissue coverage | ALT bulk may help protect against extrusion, but can complicate sizing and concealment |
| Device choice | Inflatable, malleable, and transgender-specific devices have all been used |
| Revision risk | Infection, malposition, erosion, and mechanical failure remain common across flap types |
| Function | Patients retaining a prosthesis can often achieve penetrative intercourse, but explant / revision risk is substantial |
Donor-Site Morbidity
The lateral-thigh scar is the main advantage. It is usually concealed by clothing and avoids the socially visible forearm donor site. Functional morbidity is generally acceptable, though numbness and objective strength changes can occur.[27][28][29]
| Domain | Evidence Signal |
|---|---|
| Quadriceps strength | Usually preserved subjectively; large head-and-neck ALT series show low functional morbidity[29] |
| Sensation | Donor-site numbness / tingling is common after LFCN harvest or disturbance[27][28] |
| Return to activity | Most patients return to baseline activity despite measurable sensory or strength changes |
| Closure | Primary closure depends on flap width relative to thigh circumference; large phalloplasty paddles often need grafting unless pre-expanded[30] |
Comparison With RFFF
| Feature | Pedicled ALT | RFFF |
|---|---|---|
| Donor-site scar | Concealed lateral thigh | Visible forearm |
| Microsurgery | Not required for pedicled flap | Required |
| Flap bulk | Often bulky; debulking common | Thin and pliable |
| Tube-in-tube urethra | Feasible mainly in selected thin thighs | Core design advantage |
| Sensation evidence | Promising but less robust | Stronger sensory literature |
| Flap failure | Very low | Very low |
| Urethral morbidity | Technique-dependent; can be high | High but more standardized |
| Best candidate | Wants hidden donor site / cannot use forearm | Wants best aesthetics + sensation and accepts forearm scar |
Operative Pearls
- Measure thigh thickness before promising tube-in-tube urethral construction.
- Map perforators carefully; ALT anatomy is reliable enough, but not uniform.
- Make the tunnel generous; pedicle compression or kinking can defeat the no-microsurgery advantage.
- Treat urethral construction as a separate plan, not an automatic feature of the flap.
- Tell patients upfront that debulking is usually part of the ALT journey.
- Preserve / plan LFCN strategy deliberately if sensation is a key goal.
- Keep RFFF and SCIP options in the discussion for urethral reconstruction, even when ALT is chosen for the shaft.
References
1. Netshiongolwe T, Mitchell S, Kathiravelupillai S, et al. Pedicled flaps versus free radial forearm flap for phalloplasty in female to male gender-confirming surgery: a systematic review. Ann Plast Surg. 2025;95(6):661-666. doi:10.1097/SAP.0000000000004502
2. Xu KY, Watt AJ. The pedicled anterolateral thigh phalloplasty. Clin Plast Surg. 2018;45(3):399-406. doi:10.1016/j.cps.2018.03.011
3. Terrell M, Roberts W, Price CW, et al. Anatomy of the pedicled anterolateral thigh flap for phalloplasty in transitioning-males. Clin Anat. 2018;31(2):160-168. doi:10.1002/ca.23017
4. Felici N, Felici A. A new phalloplasty technique: the free anterolateral thigh flap phalloplasty. J Plast Reconstr Aesthet Surg. 2006;59(2):153-157. doi:10.1016/j.bjps.2005.05.016
5. Morrison SD, Son J, Song J, et al. Modification of the tube-in-tube pedicled anterolateral thigh flap for total phalloplasty: the mushroom flap. Ann Plast Surg. 2014;72 Suppl 1:S22-S26. doi:10.1097/SAP.0000000000000072
6. Rubino C, Figus A, Dessy LA, et al. Innervated island pedicled anterolateral thigh flap for neo-phallic reconstruction in female-to-male transsexuals. J Plast Reconstr Aesthet Surg. 2009;62(3):e45-e49. doi:10.1016/j.bjps.2007.11.056
7. Hsieh F, Leow OQY, Cheong CF, Hung SY, Tsao CK. Musculoseptocutaneous perforator of anterolateral thigh flap: a clinical study. Plast Reconstr Surg. 2021;147(1):103e-110e. doi:10.1097/PRS.0000000000007471
8. Lee YC, Chen WC, Chou TM, Shieh SJ. Anatomical variability of the anterolateral thigh flap perforators: vascular anatomy and its clinical implications. Plast Reconstr Surg. 2015;135(4):1097-1107. doi:10.1097/PRS.0000000000001103
9. Miyamoto S, Fujisawa K, Kurita D, Shibuya M, Okazaki M. New anatomic landmark for perforator of anterolateral thigh flap in preoperative ultrasonography. Laryngoscope. 2025. doi:10.1002/lary.32223
10. Ribuffo D, Cigna E, Gargano F, Spalvieri C, Scuderi N. The innervated anterolateral thigh flap: anatomical study and clinical implications. Plast Reconstr Surg. 2005;115(2):464-470. doi:10.1097/01.prs.0000149481.73952.f3
11. D'Arpa S, Claes K, Lumen N, Hoebeke P, Monstrey S. Urethral reconstruction in anterolateral thigh flap phalloplasty: a 13-year experience. Plast Reconstr Surg. 2019;143(2):382e-392e. doi:10.1097/PRS.0000000000005222
12. Robinson I, Chao BW, Blasdel G, et al. Anterolateral thigh phalloplasty with staged skin graft urethroplasty: technique and outcomes. Urology. 2023;177:204-212. doi:10.1016/j.urology.2023.03.038
13. van der Sluis WB, Smit JM, Pigot GLS, et al. Double flap phalloplasty in transgender men: surgical technique and outcome of pedicled anterolateral thigh flap phalloplasty combined with radial forearm free flap urethral reconstruction. Microsurgery. 2017;37(8):917-923. doi:10.1002/micr.30190
14. Al-Tamimi M, Pigot GL, Ronkes B, et al. The first experience of using the pedicled labia minora flap for urethral lengthening in transgender men undergoing anterolateral thigh and superficial circumflex iliac artery perforator flap phalloplasty: a multicenter study on clinical outcomes. Urology. 2020;138:179-187. doi:10.1016/j.urology.2019.10.041
15. Staud CJ, Zaussinger M, Duscher D, et al. A modified microvascular tube-in-tube concept for penile construction in female-to-male transsexuals: combined radial forearm free flap with anterolateral thigh flap. J Plast Reconstr Aesthet Surg. 2021;74(9):2364-2371. doi:10.1016/j.bjps.2021.01.016
16. Ascha M, Massie JP, Morrison SD, Crane CN, Chen ML. Outcomes of single stage phalloplasty by pedicled anterolateral thigh flap versus radial forearm free flap in gender confirming surgery. J Urol. 2018;199(1):206-214. doi:10.1016/j.juro.2017.07.084
17. Wang E, Cleff B, Basta A, et al. Flap choice in gender-affirming phalloplasty affects postoperative complication rates. Microsurgery. 2026;46(1):e70154. doi:10.1002/micr.70154
18. Hu CH, Chang CJ, Wang SW, Chang KV. A systematic review and meta-analysis of urethral complications and outcomes in transgender men. J Plast Reconstr Aesthet Surg. 2022;75(1):10-24. doi:10.1016/j.bjps.2021.08.006
19. Ferrin PC, Burghardt E, Xu J, Peters BR. Optimizing neurorrhaphy to improve sensation in phalloplasty: a systematic review. Int J Impot Res. 2026;38(4):324-332. doi:10.1038/s41443-025-01021-w
20. Papadopulos NA, Ehrenberger B, Zavlin D, et al. Quality of life and satisfaction in transgender men after phalloplasty in a retrospective study. Ann Plast Surg. 2021;87(1):91-97. doi:10.1097/SAP.0000000000002693
21. de Rooij FPW, van de Grift TC, Veerman H, et al. Patient-reported outcomes after genital gender-affirming surgery with versus without urethral lengthening in transgender men. J Sex Med. 2021;18(5):974-981. doi:10.1016/j.jsxm.2021.03.002
22. Harris TGW, Manyevitch R, Wu WJ, et al. Pedicled anterolateral thigh and radial forearm free flap phalloplasty for penile reconstruction in patients with bladder exstrophy. J Urol. 2021;205(3):880-887. doi:10.1097/JU.0000000000001404
23. D'Arpa S, Colebunders B, Stillaert F, Monstrey S. Pre-expanded anterolateral thigh perforator flap for phalloplasty. Clin Plast Surg. 2017;44(1):129-141. doi:10.1016/j.cps.2016.08.004
24. van der Sluis WB, Pigot GLS, Al-Tamimi M, et al. A retrospective cohort study on surgical outcomes of penile prosthesis implantation surgery in transgender men after phalloplasty. Urology. 2019;132:195-201. doi:10.1016/j.urology.2019.06.010
25. Pang KH, Christopher N, Ralph DJ, Lee WG. Insertion of erectile device following phalloplasty in individuals assigned male at birth: a systematic review. J Sex Med. 2025;22(3):383-391. doi:10.1093/jsxmed/qdaf019
26. Pigot GLS, Sigurjonsson H, Ronkes B, Al-Tamimi M, van der Sluis WB. Surgical experience and outcomes of implantation of the ZSI 100 FtM malleable penile implant in transgender men after phalloplasty. J Sex Med. 2020;17(1):152-158. doi:10.1016/j.jsxm.2019.09.019
27. Noel CW, Vosler PS, Hong M, et al. Motor and sensory morbidity associated with the anterolateral thigh perforator free flap. Laryngoscope. 2018;128(5):1057-1061. doi:10.1002/lary.26865
28. Bai S, Zhang ZQ, Wang ZQ, et al. Comprehensive assessment of the donor-site of the anterolateral thigh flap: a prospective study in 33 patients. Head Neck. 2018;40(7):1356-1365. doi:10.1002/hed.25109
29. Hanasono MM, Skoracki RJ, Yu P. A prospective study of donor-site morbidity after anterolateral thigh fasciocutaneous and myocutaneous free flap harvest in 220 patients. Plast Reconstr Surg. 2010;125(1):209-214. doi:10.1097/PRS.0b013e3181c495ed
30. Chang C, Rodriguez-Mantilla I, Herrera AC, et al. Donor site in anterolateral thigh (ALT) free flaps: a systematic review of closure techniques and introduction of a management algorithm. J Plast Reconstr Aesthet Surg. 2025;105:243-259. doi:10.1016/j.bjps.2025.04.008