What is the 7-Flap Technique?
The 7-flap technique is a specific surgical method for creating a perineal urethrostomy using a laterally-based perineal skin flap shaped like the number "7" that is advanced and matured to an amputated bulbar or membranous urethra. This technique is primarily used in urology for managing complex anterior urethral stricture disease, particularly in obese patients where traditional reconstruction has failed 1, 2.
Surgical Technique
The procedure involves the following key steps:
- A "7"-shaped laterally based perineal skin flap is designed and elevated from the perineal skin 1, 2
- The flap is advanced into a spatulated, amputated bulbomembranous urethra 1
- The contralateral side of the amputated proximal urethra is then matured to the advanced perineal skin, creating the urethrostomy opening 1
- The procedure is performed entirely as an outpatient surgery with mean operative times of approximately 108 minutes 1
Clinical Applications and Outcomes
This technique is particularly valuable for obese men (BMI ≥30) with devastated urethras, as it provides reliable outcomes regardless of body habitus 1. The primary indications include:
- Advanced urethral stricture disease, particularly from lichen sclerosus (41% of cases) 1
- Failed prior urethral reconstructions (27% of cases) 1
- Complex anterior urethral stricture disease requiring definitive urinary diversion 2
Success Rates and Advantages
The 7-flap technique demonstrates exceptional success with 95% of patients voiding spontaneously without need for additional procedures at mean follow-up of 32 months 1. Key advantages include:
- No significant differences in outcomes between obese and non-obese patients (p = 0.76 for success rate) 1
- Minimal blood loss (mean 76cc) and same-day discharge for all patients 1
- Versatility in managing all levels of anterior urethral stricture disease 2
- Greater surgeon control compared to traditional perineal urethrostomy techniques 2
Important Caveats
The "7" shape refers specifically to the configuration of the perineal skin flap used in urethrostomy creation, not to be confused with other flap techniques in plastic surgery or periodontal surgery 1, 2. The laterally-based design allows maximal flexibility in positioning the urethrostomy while maintaining adequate blood supply to the flap 2.