Modified Belgrade Metoidioplasty With Urethral Lengthening
Modified Belgrade metoidioplasty is a one-stage masculinizing genital gender-affirming operation that releases the hormonally enlarged clitoris and extends the urethra to the neophallus tip using a combined buccal mucosa graft (BMG), anterior vaginal-wall flap, and labia minora flap. The operation trades a higher urethral-complication burden for the functional goal of standing micturition, which high-volume series report in most patients.[1][2][3]
This is the atlas page for the metoidioplasty-with-UL / modified Belgrade pathway. For the no-UL alternative, see Simple Metoidioplasty; for the broader cohort-level decision framework, see Masculinizing Gender-Affirming Surgery.
Indications
The modified Belgrade pathway is best suited for patients who want standing micturition, accept the limits of metoidioplasty phallic size, and prefer a sensate native-tissue neophallus over phalloplasty.[1][4][12]
| Patient Priority | Fit for Modified Belgrade Metoidioplasty |
|---|---|
| Standing micturition | Strong fit; this is the main reason to add UL |
| Preserved erogenous sensation | Strong fit; native clitoral neurovascular supply is preserved |
| Avoiding phalloplasty donor-site morbidity | Strong fit |
| Penetrative intercourse | Poor fit; mean neophallus length is limited and erectile prosthesis placement is not the endpoint |
| Lowest morbidity pathway | Poor fit; no-UL metoidioplasty has much lower urethral risk |
| Future phalloplasty flexibility | Good fit; later phalloplasty remains feasible |
Contraindications and Caution Zones
UL is the morbidity driver. Waterschoot et al. found additional urethral lengthening to be an independent risk factor for urethral complications after metoidioplasty, including all urethral complications, strictures, and fistulas.[5]
| Scenario | Counseling Point |
|---|---|
| Active smoking / nicotine use | Defer UL until cessation; smoking independently predicts fistula formation after metoidioplasty[5] |
| Standing micturition is not a priority | Prefer simple metoidioplasty or phalloplasty without UL |
| Limited labia minora / vaginal-wall tissue | May compromise flap-based urethral reconstruction; consider modified staging or alternate graft strategy |
| Retained vaginal canal planned | Counsel carefully; proximal fistula repair outcomes are worse when colpectomy is not performed before or during repair[6] |
| Penetrative intercourse is the primary goal | Phalloplasty plus delayed erectile prosthesis is usually more goal-concordant |
Historical Context
Djordjevic and colleagues reported the Belgrade experience in 2009 as a single-stage operation combining clitoral release, urethral lengthening, vaginectomy, scrotoplasty, and testicular implantation.[2] The key urethral innovation was combining a BMG dorsal plate with vascularized genital flaps rather than relying on labial skin alone.[7]
The "modified Belgrade" label usually refers to center-specific adaptations of that concept. Lin-Brande et al. described a stepwise approach that preserves the Belgrade urethroplasty principle while modifying flap design, waterproofing, and scrotoplasty sequencing for their practice.[1]
Preoperative Planning
Preoperative planning should separate the decision to perform metoidioplasty from the decision to add UL. The first is a phallic-construction choice; the second is a voiding-function choice with its own risk profile.
| Planning Domain | Practical Point |
|---|---|
| Hormone history | Most protocols require at least 12 months of testosterone to maximize clitoral hypertrophy before metoidioplasty[1][4] |
| Standing-voiding goal | Confirm that standing micturition is important enough to justify UL morbidity |
| Tobacco / nicotine | Stop preoperatively; risk counseling should be explicit because fistula is the dominant complication |
| Vaginectomy | Decide whether to perform concurrent vaginectomy / colpectomy; vaginal remnants and proximal fistulas are recurrent management problems[3][6] |
| Buccal harvest | Counsel on oral pain, numbness, cheek tightness, and diet changes |
| Testicular implants | May be simultaneous in high-volume one-stage protocols or delayed 4-6 months depending on center practice |
Technique
The modified Belgrade operation builds the neourethra in two planes: BMG forms the dorsal urethral plate on the corporal bodies, and vascularized vaginal / labia minora tissue forms the ventral tube and waterproofing layers.[1][7]
| Step | Technical Goal |
|---|---|
| Clitoral degloving and release | Deglove the clitoris circumferentially; divide superficial suspensory and dorsal clitoral tethering to maximize ventral extension |
| Urethral-plate division | Divide the short native urethral plate tethering the meatus to the ventral glans; this creates the gap that UL must bridge |
| BMG harvest | Harvest buccal mucosa from the inner cheek and prepare it as the dorsal plate graft |
| Dorsal plate construction | Quilt BMG to the ventral corporal surface from the native urethral orifice toward the glans |
| Proximal fixed urethra | Raise anterior vaginal-wall flap to bridge the native meatus to the metoidioplasty shaft base |
| Ventral pendulous urethra | Use labia minora flap to complete the ventral neourethral tube over a catheter |
| Waterproofing | Cover suture lines with vascularized labia minora subcutaneous tissue; de-epithelialized contralateral labial tissue can overlap the urethra and shaft |
| Scrotoplasty | Rotate labia majora flaps anteriorly / superiorly; use center-specific scrotoplasty design and implant timing |
| Vaginectomy / colpectomy | Perform concurrently when indicated, especially when UL is being built and proximal fistula risk is a concern |
The reconstructive principle mirrors complex hypospadias and urethroplasty logic: a stable grafted plate plus vascularized local tissue is safer than a long tube made only from marginal skin.
Belgrade Versus Ring Flap Metoidioplasty
Ring flap metoidioplasty is a different UL strategy that uses anteriorly based labia minora / vestibular flaps and avoids buccal harvest. It also preserves pedicle blood supply by not dividing the suspensory ligament in the same way.[8]
| Feature | Modified Belgrade | Ring Flap |
|---|---|---|
| Dorsal urethral plate | Buccal mucosa graft | No BMG; labia minora / vestibular flap tissue |
| Ventral urethra | Anterior vaginal-wall flap + labia minora flap | Bilateral anteriorly based labia minora and vestibular flaps |
| Oral donor-site morbidity | Yes | No |
| Suspensory-ligament division | Typically performed | Not performed in the described ring-flap approach |
| Staging | Often one-stage | Labial-fold revision and implants may be staged |
| Main advantage | Stable BMG dorsal plate | Avoids buccal harvest and preserves flap blood supply |
| Main tradeoff | Oral morbidity and graft dependence | Pedicle and flap-design constraints |
Outcomes
High-volume Belgrade series report short hospital stays, mean neophallus length around 5.6 cm, preserved erogenous sensation, and standing micturition in most patients.[2][3][13] Lin-Brande et al. reported longer operative times in their 21-patient modified series, likely reflecting early institutional experience with a technically dense operation.[1]
| Series / Technique | N | Key Outcomes |
|---|---|---|
| Djordjevic 2009 single-stage Belgrade | 82 | Standing voiding in most patients; preserved sensation; fistula and stricture remained the main complications[2] |
| Djordjevic 2009 BMG + labia minora flap | 38 | Combined BMG / labia minora UL with favorable standing-micturition and fistula outcomes compared with alternate flap choices[7] |
| Djordjevic / Bizic 2013 comparison | 207 | BMG + labia minora flap outperformed BMG + dorsal clitoral skin flap for standing micturition and fistula risk[9] |
| Bordas / Djordjevic 2021 | 813 | Mean neophallus 5.6 cm; urethral fistula 8.9%; stricture 1.7%; vaginal remnant 9.6%; testicular implant rejection 2%[3] |
| Lin-Brande 2021 modified Belgrade | 21 | Median operative time 408 minutes, EBL 400 mL, LOS 3 days; short follow-up with 9.5% stricture and no fistulas reported[1] |
| Waterschoot 2021 AUL cohort | 364 | Higher urethral-complication rates with longer follow-up; AUL independently predicted complications[5] |
| Veerman 2020 UL functional cohort | 85 metoidioplasty patients | Functional outcomes require long-term urologic follow-up because fistulas and strictures may present after the early wound-healing period[14] |
Standing micturition is the defining functional endpoint, but the number should be interpreted by center, technique, body habitus, follow-up, and how "standing voiding" was measured. The broad counseling range is: high-volume metoidioplasty centers report standing voiding in most patients, while urethral complications remain common enough that every patient should expect the possibility of repair.
Complications
Urethral Fistula
Fistula is usually the dominant complication after metoidioplasty with UL. De Rooij et al. reported that fistula repair outcomes depend on fistula size and location: small pendulous-urethral fistulas fare better than large proximal-anastomotic fistulas, and colpectomy before or during proximal fistula repair substantially improves success.[6]
| Fistula Scenario | Management Principle |
|---|---|
| Small pendulous fistula | Delay until tissue inflammation settles; multilayer closure with vascularized interposition |
| Large proximal fistula | Evaluate retained vaginal cavity / remnant; consider colpectomy before or during repair |
| Persistent or recurrent fistula | Reconstruct as a failed-UL urethroplasty problem rather than repeating simple skin closure |
| Active infection / wound breakdown | Drain, divert, and delay definitive repair |
Urethral Stricture
Endoscopic dilation or DVIU performs poorly for many post-UL strictures. Open reconstruction has better durability, and staged urethroplasty is often favored for long, complex, recurrent, or phallic urethral strictures.[6][15]
| Stricture Scenario | Preferred Direction |
|---|---|
| Short isolated anastomotic stricture | Excision and primary anastomosis may be appropriate in selected cases |
| Long pendulous / phallic stricture | Staged BMG urethroplasty often has the lowest recurrence range |
| Recurrent after dilation / DVIU | Move to open repair rather than serial endoscopy |
| Associated fistula / vaginal remnant | Treat the entire failed-UL unit; repair sequencing matters |
Non-Urethral Complications
Other complications include wound separation, vaginal remnant, testicular implant rejection or displacement, oral donor-site morbidity, and dissatisfaction with phallic size for penetrative function.[3][10]
Emerging Modifications
Nakamura et al. described vaginal-mucosal graft metoidioplasty, using mucosa harvested during vaginectomy to replace buccal mucosa for urethral reconstruction. The attraction is obvious: the graft source is already being removed, avoiding oral morbidity. Early data are limited to a small short-follow-up cohort, so this should be framed as an emerging alternative rather than a replacement for BMG-based Belgrade reconstruction.[11]
Operative Pearls
- Treat UL as the risk-bearing part of the operation, not as a minor add-on to clitoral release.
- Preserve vascularized labia minora tissue for both ventral urethral construction and waterproofing.
- Do not over-tubularize tight tissue over a large catheter; ischemia and tension are fistula invitations.
- If a vaginal remnant is present, look for it before repairing proximal fistula.
- Counsel on standing voiding separately from stream quality; spraying and dribbling may persist even when the patient can void standing.
- Keep phalloplasty conversion feasible by minimizing avoidable donor-site and perineal scarring.
References
1. Lin-Brande M, Clennon E, Sajadi KP, et al. Metoidioplasty with urethral lengthening: a stepwise approach. Urology. 2021;147:319-322. doi:10.1016/j.urology.2020.09.013
2. Djordjevic ML, Stanojevic D, Bizic M, et al. Metoidioplasty as a single stage sex reassignment surgery in female transsexuals: Belgrade experience. J Sex Med. 2009;6(5):1306-1313. doi:10.1111/j.1743-6109.2008.01065.x
3. Bordas N, Stojanovic B, Bizic M, Szanto A, Djordjevic ML. Metoidioplasty: surgical options and outcomes in 813 cases. Front Endocrinol. 2021;12:760284. doi:10.3389/fendo.2021.760284
4. Kocjancic E, Acar O, Talamini S, Schechter L. Masculinizing genital gender-affirming surgery: metoidioplasty and urethral lengthening. Int J Impot Res. 2022;34(2):120-127. doi:10.1038/s41443-020-0259-z
5. Waterschoot M, Hoebeke P, Verla W, et al. Urethral complications after metoidioplasty for genital gender affirming surgery. J Sex Med. 2021;18(7):1271-1279. doi:10.1016/j.jsxm.2020.06.023
6. de Rooij FPW, Falcone M, Waterschoot M, et al. Surgical outcomes after treatment of urethral complications following metoidioplasty in transgender men. J Sex Med. 2022;19(2):377-384. doi:10.1016/j.jsxm.2021.12.006
7. Djordjevic ML, Bizic M, Stanojevic D, et al. Urethral lengthening in metoidioplasty (female-to-male sex reassignment surgery) by combined buccal mucosa graft and labia minora flap. Urology. 2009;74(2):349-353. doi:10.1016/j.urology.2009.02.036
8. Demzik A, Snyder L, Hayon S, Chen M, Figler BD. Ring flap metoidioplasty. Urology. 2021;158:243. doi:10.1016/j.urology.2021.09.014
9. Djordjevic ML, Bizic MR. Comparison of two different methods for urethral lengthening in female to male (metoidioplasty) surgery. J Sex Med. 2013;10(5):1431-1438. doi:10.1111/jsm.12108
10. 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
11. Nakamura K, Sakurai T, Sakamoto A, Watanabe K, Ogawa R. Vaginal-mucosal graft metoidioplasty: a novel surgical technique for urethral reconstruction in transmasculine surgery. J Sex Med. 2025;22(7):1275-1279. doi:10.1093/jsxmed/qdaf125
12. Bizic M, Stojanovic B, Bencic M, Bordas N, Djordjevic M. Overview on metoidioplasty: variants of the technique. Int J Impot Res. 2021;33(7):762-770. doi:10.1038/s41443-020-00346-y
13. Stojanovic B, Djordjevic ML. Updates on metoidioplasty. Neurourol Urodyn. 2023;42(5):956-962. doi:10.1002/nau.25102
14. Veerman H, de Rooij FPW, Al-Tamimi M, et al. Functional outcomes and urological complications after genital gender-affirming surgery with urethral lengthening in transgender men. J Urol. 2020;204(1):104-109. doi:10.1097/JU.0000000000000795
15. Neuville P, Madec FX, Vetterlein MW, et al. Systematic review of the outcomes of urethroplasty following urethral lengthening in transgender men. Int J Impot Res. 2026;38(4):302-310. doi:10.1038/s41443-025-01132-4