The aim of this study is to assess inhibiting effect of pentoxifylline on intimal hyperplasia and smooth muscle cell proliferation at the anastomosis site performed in rabbit carotid artery.

Objective: Intimal hyperplasia and smooth muscle cell proliferation play an important role on the restenosis after the vascular interventions. Reconstruction is one of the most common intervention in the management of the obstructing artery diseases. Recently, the success of these kind of interventions are under expectations because of spontaneous thrombosis or restenosis. After vascular reconstructive interventions unlikely the acute obstruction in which acute thrombosis is important at the late stage intimal hyperplasia caused by smooth muscle cell migration, proliferation and extracellular matrix deposition play an important role in narrowing or restenosis. Hyperplasic intimal thickening is not only an adaptive progress against the hemodynamic stress but also a characteristic of arterial injury healing. We assess the effect of pentoxifylline on intimal hyperplasia and smooth muscle cell proliferation at anastomosis performed in rabbit carotid artery.Materials and Method: In this study we planned to use 18 randomized New Zealand male rabbit weights 2 to 3 kilograms. Rabbits were seperated to 3 groups. A vertical neck insition was made in an appropriate position to all group rabbits and carotid artery was dissecated. The same artery transected and using 8/0 polypropylene an anastomosis was performed with by one by technique. Group 1 rabbits (6) assigned as control group. No medication was given to this group. Pentoxifylline was administrated to group 2 100 mgr/kg/day per subcutaneus during 7 days. Group 3 rabbits was given to Pentoxifylline 100 mgr/kg/day per subcutaneus during 21 days. At the end of the day 28 the anostomosis performed carotid artery segments and the contralateral carotid artery of all rabbits were sent to histology laboratory to analyze. The preperations were examined under light microscope. Images were analyzed via digital image analyze program and lumen diamater, lumen area, intima-media area ratio were estimated and results were evaluated. Serial cross-sections taken from paraffin tissues were photographed and transferred to computer environment. Intima and media thicknesses were measured and the sections were three dimensioned via Reconstruct 1.0.9.9 (JC Fiala) program.Findings: In the serial sections the average lumen diamater of group 3 was found higher than the group 1 and group 2 and this difference was statically significant between group 1 and group 3 but not between group 2 and group 3. The lumen diameter of group 2 was higher than group 1 and the difference was significant. The lumen area of group 3 was found higher than the group 1 and group 2 and this difference was significant between group 1 and group 3 but not between group 2 and group 3. The lumen area of group 2 was higher than group 1 and the difference was significant. When the section series were evaluated for intimal thickness, thickness of group 3 was lesser than group 1 and group 2 and the difference was statically significant between group 1 and group 3 but not between group 2 and group 3. The intimal thickness of group 2 was lesser than group 1 and the difference was statically significant. The evaluation of intima /media ratio showed that it was higher in group 1 compared with group 2 and group 3 and the difference was significant. Despite the higher intima/media ratio of group 2 against group 3 the difference was not statistical significant. There was no significance in the control groups in terms of lümen diameter, lumen area and intima-media ratio values.Conclusion: Pentoxyfillin may be a beneficial agent for preventing intimal hyperplasia and smooth muscle cell proliferation after the vascular surgery.Key words: Pentoxyfillin, intimal hyperplasia, smooth muscle cell proliferation, anastomosis, rabbit.