Tunica Vaginalis vs Dartos Flap Coverage in Distal and Mid-Shaft Hypospadias Repair
Overview
This prospective randomized trial compared tunica vaginalis flap (TVF) and dartos flap (DF) as secondary layers in tubularized incised plate (TIP) repair of distal and mid-shaft penile hypospadias. Both techniques demonstrated effective neourethral coverage with low complication rates, but TVF provided a well-vascularized, abundant flap without risk of penile torsion. The study supports the use of TVF as a reliable alternative to DF in primary hypospadias repair.
Background
Hypospadias is a common congenital anomaly characterized by ventral displacement of the urethral meatus, with a prevalence exceeding 50 per 10,000 births. Surgical repair aims to restore both function and cosmesis, commonly using tubularized incised plate (TIP) urethroplasty. Urethrocutaneous fistula (UCF) remains the most frequent and challenging postoperative complication, with incidence rates up to 50%. Secondary layer coverage of the neourethra, using vascularized flaps such as dartos or tunica vaginalis, has been shown to reduce fistula formation. However, comparative data from prospective randomized trials remain limited.
Data Highlights
Parameter
Dartos Flap Group (n=44)
Tunica Vaginalis Flap Group (n=44)
Age Inclusion
≥6 months
≥6 months
Type of Hypospadias
Distal or mid-shaft
Distal or mid-shaft
Urethrocutaneous Fistula Rate
Reported range 0-50% (general literature)
High success rate reported in literature
Flap Width
Variable dorsal or ventral dartos flap
15–20 mm tunica vaginalis strip
Randomization
1:1 closed envelope technique
1:1 closed envelope technique
Key Findings
Both dartos and tunica vaginalis flaps provide effective secondary coverage for neourethra in TIP repair of distal and mid-shaft hypospadias.
Dartos flap harvesting may risk penile torsion and compromise dorsal preputial blood supply if aggressively dissected.
Tunica vaginalis flap offers abundant, well-vascularized tissue unaffected by penile anatomy or prior surgeries.
TVF harvesting involves delivering the testis and dissecting a pedicled flap from the tunica vaginalis, preserving spermatic fascia to maintain vascularity.
Randomized allocation and standardized surgical technique by experienced pediatric urologists ensured comparability between groups.
Postoperative management included elastic penile wrapping and antibiotic prophylaxis to optimize healing.
Clinical Implications
Surgeons performing TIP hypospadias repair should consider tunica vaginalis flap as a reliable secondary coverage option, especially when concerns exist regarding dartos flap viability or risk of penile torsion. TVF provides a robust, well-vascularized layer that may reduce fistula rates and improve surgical outcomes. Familiarity with TVF harvesting technique and careful preservation of vascular pedicle are essential to maximize benefits.
Conclusion
This prospective randomized study supports the use of tunica vaginalis flap as an effective and safe alternative to dartos flap for secondary neourethral coverage in distal and mid-shaft hypospadias repair. Incorporation of TVF may enhance surgical success and reduce postoperative complications.
References
Al-Shammari et al. 2022 -- Exploring the Use of Tunica Vaginalis or Dartos as Secondary Layer Coverage in Distal and Mid-Shaft Penile Hypospadias Repair
