Microvasculature and healing potential of the inner versus outer preputial skin: preliminary immunohistochemical observations.

PURPOSE: To assess healing potential of the inner and the outer layers of the prepuce and to determine which layer is better for hypospadias neourethral reconstruction.
MATERIALS AND METHODS: The study has been carried out to assess the microvessels density and epidermal growth factor receptor (EGFR) concentration in the inner and the outer preputial layers. Specimens from the outer and the inner prepuce were harvested during hypospadias repair in 26 children. Control specimens were collected during elective circumcision of 10 normal and age-matched children. Sections were prepared, and immunohistochemical staining was done using monoclonal antibodies of CD34 (vascular marker) and of the EGFR. CD34-positive microvessels were assessed under the outer and the inner layers of the prepuce and were counted in five high-power fields under each layer. Expression of EGFR in both layers was assessed using H-score system.
RESULTS: The density of microvessels and EGFR expression are significantly higher in control group either for inner or for outer preputial layers (p < 0.05). Microvessels density in the inner prepuce in hypospadias group is slightly higher than that of the outer prepuce (p < 0.05). However, the wider lumen and well-developed wall of the microvessels in the outer layer may compensate for decreased number in comparison with the inner layer. Expression of EGFR was reduced in both inner and outer layers of the hypospadias prepuce with no significant difference (p > 0.05).
CONCLUSION: In hypospadias patients, the healing potential of both inner and outer prepuce is nearly similar. However, it is markedly reduced than that of normal prepuce. It seems that both layers can be used for hypospadias repair without obvious preference to either of them. The usual tradition to use inner prepuce in hypospadias repair has no scientific evidence.