Table 2: Number of vessels in porcine split-thickness skin-graft donor sites covered with either human amniotic membrane or polyurethane foil on postoperative days 7 and 10 (evaluated by immunohistochemical staining with von Willebrand factor antibody).

Wound dressing materialMean value ± standard error of the mean 
(number of vessels per high-power field)
The 7th postoperative dayThe 10th postoperative day

Human amniotic membrane0.90 ± 0.181.05 ± 0.14
Polyurethane foil1.80 ± 0.164.70 ± 0.47