Transferred Free Flaps - Biological Values

Introduction: Microvascular transfer of tissues provides a single act of the flap transfer to any part of the body by applying microvascular anastomosis. Wide specter of indications for applying free flaps assumes various aims of the microvascular reconstruction. The need for a good perfusion of local tissue in complex fracture of limbs' long bones or sensitivity in flaps transferred to feet, palms, face, breasts, genitals, etc., require a reconstructive microsurgeon's optimal choice of a free flap.

Methodology and Material: At the Clinic for plastic surgery and burns of the Military Medical Academy, we examined 33 patients with transferred 5 cutaneous, 18 miocutaneous and 10 osteocutaneous free flaps of which on foot -10, lower leg - 13 and on face - 10. We analyzed blood circulation, sensitivity recovery, functioning of the sebaceous and sweet glands as well as histomorphologic changes in the skin of the transferred free flaps during the period of 6 up to 36 months after the free flap transfer.

The patency of the arterial microvascular anastomosis we evaluated by using Seldinger's arteriography, while the perfusion in the flap tissue was evaluated by the Tc-99m (MAA HSA) radionuclear arteriography. By Von Frey test we tested touch sensitivity and recovery; hot and cold sensitivity was tested by thermosteziometre and hot +10 or + 40o C waves. We evaluated pain sensitivity by using Bernard's diadynamic current of 100 MHz frequency and 1-15 mA intensity. The two-point discrimination test we used to definethe quality of the established sensitivity. The Herman-Prose's test was used for testing functioning of the sebaceous glands while ninhidrinic test was used for testing functioning of sweat glands. By light microscopy and application of various histochemical and imunochemical dyeing methods the histopathologic changes in the transferred free flaps' skin were evaluated.

Results: Through its passable arterial micro anastomosis, blood circulation in transplanted free flaps has preserved the autonomy of its vascular network which provides better perfusion than the recipient region's surrounding perfusion. The tests conducted showed that all senses (touch, pain, hot, cold) were partially recovered but even after 36 months they could not reach the level or the quality of the recipient region's surrounding. Functioning of the free flaps' sebaceous glands is worse than that of the glands in the recipient's surrounding which is probably the result of the denervation processes. Functioning of the sweat glands is in correlation with the skin reinervation process initiated by nerves spreading out from the surrounding tissue.

Conclusions: Histopathologic changes in the free flaps' skin have probably resulted from denervation and inflammatory process that occurred during the microvascular tissue transfer.