Short-term changes in a chicken comb vascular model mimicking port-wine stain after synchronous ultrasound parallel beam treatment: an exploratory study

Synchronous ultrasound parallel beam (SUPERB) technology heats the mid-dermis without relying on hemoglobin as an optical chromophore, but its effect on the cutaneous microvasculature has not been reported. We examined short-term responses of a hypervascular chicken comb model to SUPERB treatment combined with applicator compression. In six adult roosters, two sites on the left comb surface each received a single pulse of 3 to 5 J after compression blanching, and the right surface served as a within-animal control. Full-thickness biopsies were taken immediately after treatment and on days 3 and 7; one rooster died on day 2, leaving five for analysis. Hematoxylin and eosin sections were assessed descriptively by a blinded pathologist, and vascular endothelial growth factor A (VEGF-A) positive area and Masson collagen area were quantified on day 7 at the animal level. Reduced microvascular caliber and fewer intraluminal erythrocytes were recorded at 1 of 10 sites immediately after treatment, 8 of 10 sites on day 3 and 8 of 9 evaluable sites on day 7. On day 7, VEGF-A positive area was lower on the treated side in all five animals (11.5% vs. 20.5%; mean paired difference -9.1 percentage points, 95% confidence interval -13.3 to -4.9; exact Wilcoxon p = 0.0625, the smallest value attainable with five pairs). Collagen area did not change consistently. Tissue temperature and perfusion were not measured, and no sham-compression group was included. These hypothesis-generating findings support controlled studies that separate the effects of compression and ultrasound energy.