DERMAL MICROVASCULATURE AND TISSUE-SELECTIVE THINNING TECHNIQUES (ULTRASOUND AND WATER-JET) OF SHORT-TIME EXPANDED SKIN IN DOGS

Certain reconstructive procedures, like auricular reconstructions, req uire thin and well-vascularized skin. The aims of this study were to a nalyze if the increased survival of expanded skin flaps was due to mor phologic changes of the dermis, if thinning of short-time expanded ski n was possible without harm to the microcirculation and if tissue sele ctive cutting methods could be used to resect subcutaneous fat without damaging its vessels. Eighty-two 200-ml expanders were implanted into the trunk regions of 26 beagles and filled immediately with sterile s aline. In the first series of experiments, the expansion was terminate d after intervals of 0.5-5 weeks and dermal vessels were analyzed morp hometrically. In the second series the expanded flaps were raised afte r 2 weeks and thinned solely surgically or with the additional use of an ultrasonic knife or with cutting by water jet. In contrast to sham flaps, the expanded skin showed only very few areas of necrosis and th ese were located superficially in most cases. The relative volume of t he dermal vessels and their quantity showed a significant increase aft er the expansion. Additionally, the subcutaneous tissue could be thinn ed down to 0.4 mm with the water-jet-cutter. Findings demonstrated tha t the method used could create a well-vascularized skin flap of minima l thickness that could be very helpful for special reconstructive proc edures.