PREDICTING THE SURVIVAL OF EXPERIMENTAL SKIN FLAPS WITH A KNOWLEDGE OF THE VASCULAR ARCHITECTURE

Experimental skin flaps have been utilized by researchers for almost a century to investigate many of the perplexing questions in plastic an d reconstructive surgery, yet the underlying vascular anatomy of these flaps is addressed infrequently. The purpose of this study was to pre dict the survival of experimental skin flaps prior to their elevation in guinea pigs and rabbits, planned on a knowledge of the underlying v ascular anatomy. On the basis of our previous anatomic studies, 17 gui nea pigs and 15 rabbits were used in separate experiments. In experime nt 1, two parallel flank flaps of identical dimensions were compared o n one side of each guinea pig. The dorsal flap encompassed the vascula r territories of multiple perforators, while the ventral flap embraced two perforators (two-territory flap). Viability was assessed on days 3 and 7 by inspection and fluorescein dye injection. All ventral flaps survived to a greater extent than the dorsal flaps. Whole-body fresh cadaver lead oxide injections were performed to provide cutaneous angi ograms. It was found in each flap that the area of skin viability corr esponded to the capture of one to two adjacent vascular territories on the artery at its base. In the second experiment, a multiple-territor y osteocutaneous flap was designed on one side of the torso of the rab bit using the Doppler probe. It was based on the thoracodorsal artery and embraced the skin and a 1 x 2 cm segment of iliac crest bone in th e adjacent deep circumflex iliac artery angiosome. Using the same crit eria as in experiment 1, we found that one to two adjacent viable skin territories were captured on the thoracodorsal artery. In addition, v iability of the iliac bone was confirmed in every case by angiography, fluorochrome labeling, and india ink injection studies indicating the capture of deep structures of the deep circumflex iliac artery angios ome. This study reinforces the angiosome concept and indicates that on e adjacent vascular territory may be captured reliably in experimental guinea pig and rabbit skin flaps. In addition, we have described a re liable osteocutaneous flap model in the rabbit.