Isotope perfusion and infrared thermography of arterialised, venous flow-through and pedicled venous flaps

In an experimental study on the epigastric venous system of rats, we examined three types of venous flaps with regard to their perfusion and long-term results: arterialised venous flaps, flow-through venous flaps and venous island flaps. We documented afferent and efferent blood flow with radiolabelled substances and blood distribution with infrared thermography. By measuring the surviving flap surfaces after 4 months, the relative success rate for each flap type was determined. The results show that in the chosen model the entire surface of the arterialised venous flap had a survival rate of 92.7 %, the flow-through venous flap 62.4 %, and the venous island flap about 31 %. The venous island flaps had the worst distribution of intravenously injected125J-Fibrinogen, and it was significantly worse in all types of venous flaps than in standard epigastric flaps; moreover, the clearance of intracutaneously injected99mTc was the lowest in venous island flaps. The infrared thermographic study showed that the blood in the arterialised venous flaps dispersed faster and over a larger area than in flow-through venous and island flaps. Given these results, we conclude that arterialised venous flaps are the safest form of venous flaps, whereas venous island flaps carry a high risk of partial or total necrosis.