Investigation of vessel lengthening technique by traction forces for distant tissue transfer

It has been known that tissue regeneration supplied by mechanical forces is possible like tissue expansion and distraction osteogenesis principles. In case of inadequate vessel length, as in arterial gap or flap pedicle falling short, there is a need for additional techniques. Additionally, absence of appropriate recipient vessels and presence of vascular pathologies may render microvascular anastomosis impossible. In search of a solution, we made a technique defining study investigating the effects of mechanical traction applied by an internal maxillofacial distractor device on major vessels of rat; femoral artery and vein and named the technique "traction vasculogenesis". At the end of the traction period, vessel length, blood flow patency, histologic and biochemical effects were evaluated. A total number of 30 Wistar-Albino rats were used. (15 control and 15 experiment) Under general anaesthesia, left femoral artery and vein of the rats were isolated and traction was applied for 1 mm per day for 10 days by a distraction device. In control group, vessels were isolated but no traction was applied. In the results, significant vessel length gain was found in experiment group compared to the control group. (Control= 12.86 mm, Experiment=21.93 mm, p<0.05) There was no thrombosis in the control group. (n=0) In the traction group 20 percent arterial and venous co-thrombosis was observed. (n=3) There was no isolated arterial or venous thrombosis. There was no statistical significance between control and traction groups in blood flow. (p>0.05) In the microangiographic studies vessel patency was observed in both groups. In the histologic studies of femoral artery and vein sections, thickening in vessel wall, perivascular PMNL infiltration was seen. In the rats which had no blood flow (n=3) intravascular thrombosis was observed in both artery and vein. In the biochemical studies, there was no statistically significant difference of hemolisate and tissue MDA, serum, hemolisate and tissue SOD, plasma VEGF and AT-III between control and traction groups. This technique is a pilot study for obtaining vessel length without losing blood flow patency in vascular surgery and its results are promising for further experimental studies and clinical adaptation. With further research we think that this experimental technique is not far from clinical applications.