The vascular evolution of an extended flap on the dorsum of rats and the potential involvement of MMP-2 and MMP-9

•We first adopt the panoramic photographing technique and the dorsal skinfold technique together for image capturing.•We first examine ultrastructural change of choke vessels after flap harvest.•We first examine both the location and quantity of expression, and activity of MMP2 and 9 during choke vessel dilation.•We first examine the denervation process in the choke region after flap harvest.•We first propose the detailed venous drainage path after flap harvest.