PRETREATMENT WITH CYPRESS CONES' WATER EXTRACT ENHANCES SURVIVAL OF ISCHEMICALLY CHALLENGED SKIN FLAPS A PRELIMINARY STUDY

Özet

The pathophysiology of ischemic skin flap necrosis is complex, due primarily to vascular thrombosis and insufficient angiogenesis. Nitric oxide can significantly increase angiogenic response and protect the endothelium from ischemia-reperfusion injury. Also, anticoagulants can prevent or reverse skin flap ischemia. In vitro assessment of endothelial cell function in isolated aortic rings of rats pretreated with cypress cones' water extract showed increased production of endothelium-derived nitric oxide. Additionally, we have shown its anticoagulant properties. Based on these observations, we hypothesized that pretreatment with cypress cones' water extract would enhance survival of random extensions of ischemic axial flaps via its increased endothelial nitric oxide release and its anticoagulant effect.Twenty four Sprague-Dawley rats were randomly assigned as pretreatment (n = 12) and control (n=12) groups. The pretreated group received 30% of cypress cones' water extract treatment orally 7 days before flap elevation and for 3 days afterward. The control group received tap water. The ischemic target was a 6 X 7 cm islanded epigastric artery flap based on the right inferior epigastric pedicle. After the observation period, hemodynamic variables including mean arterial pressure and heart rate were assessed. Flap survival and perfusion rates were determined by microangiography and laser Doppler flowmetry. In twelve rats, in vitro isometric tension of the aortic segments isolated from the control and pretreated groups was monitored to reflect vascular responsiveness. Using isolated tissue baths, the dose-response relations to acetylcholine was determined and compared between the two groups.
There were no significant differences between the hemodynamic variables. In the pretreated group, microangiograms revealed increased angiogenesis and capillary density and enhanced flap perfusion (as blood perfusion units) in the right distal and proximal parts (P .05). Endothelium-derived nitric oxide - dependent maximal relaxation (Emax) and the EC50 value to Acetylcholine were significantly greater in the pretreated group compared to that of the controls. These data suggest that pretreatment with cypress water extract enhances the viability of ischemically challenged flaps.