Scrotal Flaps for UCF Repair
Scrotal tissue can supply vascularized coverage for a urethrocutaneous fistula (UCF) when local penile tissue is inadequate. Scrotal dartos, de-epithelialized skin and septocutaneous flaps are different reconstructions; their indications and complications should not be combined into one guaranteed outcome.[1][2][3][4]
The 2023 UCF-repair review reported 94.6% success for scrotal flaps and 94.3% for tunica vaginalis. Those pooled proportions come from heterogeneous studies and do not prove that scrotal flaps are superior or that either rate applies to every recurrent fistula.[1]
See Simple Closure and Skin Advancement, Double Dartos, PATIO and Tunica Vaginalis Flap for related options.
Tissue choice and anatomy
A 15-cadaver study described external pudendal and perineal arterial contributions to two lateral and one central scrotal skin territories, with extensive anastomoses. This anatomical redundancy supports flap design, but it does not guarantee an undamaged pedicle after prior surgery, trauma or infection.[5]
| Tissue | Reconstructive role | Distinction |
|---|---|---|
| Scrotal dartos | Vascularized interposition over a closed urethra. | Harvested from the scrotal wall; it is not the tunica vaginalis surrounding the testis.[2][6] |
| De-epithelialized scrotal skin | Reinforcement outside the urethral lumen. | Retains vascularized underlying tissue after removing the surface epithelium.[3] |
| Septocutaneous skin flap | Selected reconstruction of urethral lining and/or an external defect. | This introduces different concerns, including intraluminal hair when skin forms the urethra.[4][8] |
| Local turnover dartos flap | Hinged tissue beside the fistula is turned over the urethral closure. | In Ahuja's description the overlying skin may come from the penile shaft or scrotum; the interposition flap is not necessarily a scrotal flap.[7] |
Assess fistula number and size, distal obstruction, associated urethral loss, local and donor tissue quality, flap reach and prior operative scars. A flap should reach without traction or twisting. Previous inguinal or scrotal surgery warrants assessment of both dartos and tunica options; it does not automatically establish that one is unavailable and the other unaffected.[1][6][10]
Operative principles for interposition
- Plan the urethral repair first. Define the tract and any associated obstruction or breakdown. Primary fistula closure and reconstruction of a larger urethral defect are different procedures.
- Select and mobilize viable tissue. Preserve the chosen flap's vascular base and donor skin perfusion. Scrotal dartos can provide a pedicled layer when local penile dartos is scarred or deficient.
- Transfer with adequate reach. Bring the flap to the urethral closure without pedicle compression, twist, penile rotation or excessive traction.
- Cover the repair. Secure vascularized tissue over the relevant urethral suture line with appropriate fine absorbable sutures. Avoid unnecessary bulk or luminal compression.
- Close and reassess. Obtain tension-free superficial coverage, evaluate donor and recipient perfusion, and choose drainage according to the underlying repair.[2][3][6][10]
Scrotal dartos harvest usually avoids opening the tunica vaginalis. Tunica vaginalis harvesting involves a different dissection around the testis and cord. Neither distinction establishes zero donor-site risk or a universal need for orchiopexy in every technique; see the dedicated tunica vaginalis page for its operative approach.[2][10]
Results with their actual populations
| Source | Population and outcome | Limit |
|---|---|---|
| Lee 1990 | Eight UCF closures, mostly penoscrotal; no recurrence reported. Three were performed without urinary diversion or a urethral stent. | The same report also included 15 hypospadias reconstructions, three of which developed a fistula distal to the original opening. Do not combine all procedures as zero-fistula repairs.[3] |
| Churchill 1996 | Eight complex reconstructions included six repeat hypospadias operations; no fistula was reported in those six at one year. | The other two cases had different diagnoses. This is not eight successful isolated UCF closures, and reported cosmetic success was not universal.[2] |
| Muruganandham 2010 | Twenty-one patients with 2–4 mm fistulas received scrotal dartos coverage; two recurred during the study's mean 3.5-year follow-up. | Technique was selected by defect size. Comparison with smaller fistulas receiving simple closure or larger defects receiving tunica vaginalis is confounded.[6] |
| Ahuja 2009 | Ten patients received a local de-epithelialized turnover flap. Nine healed without complications; one residual pinpoint fistula subsequently closed spontaneously. | Final closure in all ten is not ten immediately uncomplicated repairs, nor evidence specific to scrotal harvest.[7] |
These studies support feasibility in selected patients. They do not establish a universal size-based hierarchy, superiority to tunica vaginalis, or freedom from testicular or scrotal complications.[1]
Skin used as urethral lining
Historical septal and biaxial scrotal skin flaps were developed for complex urethral reconstruction. Mokhless reported satisfactory results in five of seven complex hypospadias patients, with distal strictures in two and hair growth in one. Gil-Vernet's series concerned 37 men with urethral stenosis, reporting normal voiding in 86%; it is not a UCF-closure cohort.[8][9]
Current EAU urethral-stricture guidance recommends avoiding hair-bearing perineal or scrotal flaps unless no other option is feasible. Intraluminal hair may contribute to infection, calculi and failure. Historical epilation techniques do not make untreated hair-bearing skin a routine urethral substitute. A dartos layer placed outside an intact closed urethra serves a different purpose and does not deliberately line the urinary lumen.[12]
Donor-site risk and follow-up
Discuss hematoma, infection, skin or flap compromise, tethering, cosmetic change, recurrent fistula and possible further surgery. Small UCF series that observed no testicular injury cannot exclude that risk. A separate 22-patient study of bilateral scrotal flaps for penile shaft skin replacement reported testicular ascent in 22.7%; that rate must not be assigned to scrotal dartos interposition for UCF.[6][11]
Drainage and recovery restrictions depend on the urethral repair, contamination, tissue condition and surgeon's protocol. Some small repairs have been managed without diversion; neither a compulsory catheter duration nor routine suprapubic drainage follows from the scrotal-flap literature. Follow healing, urinary stream, donor-site recovery and symptoms of recurrence or obstruction.[3][6][10]
References
1. Choudhury P, Saroya KK, Jain V, et al. "'Waterproofing layers' for urethrocutaneous fistula repair after hypospadias surgery: evidence synthesis with systematic review and meta-analysis." Pediatr Surg Int. 2023;39(1):165. doi:10.1007/s00383-023-05405-1
2. Churchill BM, van Savage JG, Khoury AE, McLorie GA. "The dartos flap as an adjunct in preventing urethrocutaneous fistulas in repeat hypospadias surgery." J Urol. 1996;156(6):2047–2049.
3. Lee SE, Kim KM, Kim YK. "De-epithelialized scrotal flap in repair of urethrocutaneous fistula and hypospadias." Urology. 1990;36(2):160–163. doi:10.1016/0090-4295(90)80217-b
4. Sakai S, Soeda S, Yoshii S. "Scrotal septocutaneous island flap for the reconstruction of the urethral fistula." Ann Plast Surg. 1990;24(1):49–52. doi:10.1097/00000637-199001000-00009
5. 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):820–824. doi:10.1111/j.1464-410X.2008.08167.x
6. Muruganandham K, Ansari MS, Dubey D, et al. "Urethrocutaneous fistula after hypospadias repair: outcome of three types of closure techniques." Pediatr Surg Int. 2010;26(3):305–308. doi:10.1007/s00383-009-2490-z
7. Ahuja RB. "A de-epithelialised 'turnover dartos flap' in the repair of urethral fistula." J Plast Reconstr Aesthet Surg. 2009;62(3):374–379. doi:10.1016/j.bjps.2008.03.031
8. Mokhless I. "Modified vascularized pedicled scrotal flap for complex hypospadias." J Urol. 1992;148(1):55–57. doi:10.1016/s0022-5347(17)36507-2
9. Gil-Vernet J, Arango O, Gil-Vernet A, Gil-Vernet J, Gelabert-Mas A. "A new biaxial epilated scrotal flap for reconstructive urethral surgery." J Urol. 1997;158(2):412–420.
10. Landau EH, Gofrit ON, Meretyk S, et al. "Outcome analysis of tunica vaginalis flap for the correction of recurrent urethrocutaneous fistula in children." J Urol. 2003;170(4 Pt 2):1596–1599. doi:10.1097/01.ju.0000084661.05347.58
11. 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
12. European Association of Urology. EAU Guidelines on Urethral Strictures: Tissue Transfer, section9.2. 2026. Guideline.