Morphological changes in the vascularisation of delayed flaps in rabbits.

The effect of the delay phenomenon on the vascularisation of the pectoralis major myocutaneous flap was studied in 32 rabbits. In 36 flaps, submitted to different methods of delay, vascularisation was studied by making the tissue transparent and comparing the results with a control group of 16 undelayed flaps. In another 12 flaps, 6 of them previously delayed, the vascularisation of the skin was studied by light microscopy and through a morphometric analysis (image digitalizing process). Delayed flaps showed a significant (P less than 0.0001) increase of their vascularisation related to the undelayed flaps (average vascular area in the slides of 0.04 mm2 and 0.01 mm2 respectively). In addition, there were a nonspecific inflammatory reaction and angiogenesis, that could contribute to the increase of the vascularisation.