The use of thermography to design tissue flaps - experimental studies on animals

Methods allowing one to locate the position of a cutaneous perforator do not allow one to determine the boundaries of the vascularized skin. In clinical practice this causes complications in the form of marginal necrosis of the flap.

To examine the usefulness of thermography to assess the extent of vascularization of the skin and subcutaneous tissue by a single perforator.

Thirty-one male rats were used. Using dynamic thermography the perforators on the abdominal skin were located. Afterwards the flap was prepared on a randomly chosen perforator. After 24 h the extent of vascularization of the skin by a single perforator was examined.

In 22.5% of cases the number of perforators marked in the thermography was equal to the number of perforators marked intraoperatively, in 64.5% it was lower and in 13% higher. The use of thermography has shown that basing the flap vascularization on the perforator with low efficiency resulted in statistically more frequent occurrence of ischemia and partial necrosis of the flap (p = 0.024). Partial necrosis of the flap occurred in 12 of 31 cases, always in the area in which during the preoperative thermography no perforators were found. The areas of necrosis occurred irrespectively of the distance from the supplying vessel.

When designing the shape of the flap, the distribution of all perforators must be considered. The perforators need to be included in the area of prepared tissues because their location indicates the area with a more efficient network of vessels.