Effects Of Foam Sclerotherapy (Polidocanol) On Varicose Great Saphenous Vein In Different Concentration And Time

Background:For nearly half a century,foam sclerotherapy has been widely used in the treatment of varicose veins of lower extremity,and have been accepted as more effective than the liquid form.In contrast to the liquid form,the foam form can rapidly induce vasospasm,which is less diluted by the blood in the vein,thereby further enhancing the effect.However,there is no clear consensus on the minimum effective time and the minimum efective concentration of foam sclerotherapy.Objective:The aim of this study was to investigate the minimum acting time and concentration of widely used foam sclerosant(polidocanol)as well as its histopathological effect on varicose great saphenous vein.Methods:varicose vein segments of 5-10 mm diameter were gently resected and exposed to various concentrations of polidocanol foam sclerosant(0.5%,1%,3%)for various time(1s,10s,30s,1min,5min,10min),and were then prepared for routine histopathological examination.At the same time,The control group was set up:the small venous segment of the length of the 1cm in each 10cm segment was placed in 10%of the Formaldehyde Solution fixation.A total damage scoring system,including the presence of endothelial swelling,intimal thickening,cellular vacuolization in the muscle layer,edema in the tunica media and extent of necrosis,was established.Finally,statistical method is used to draw a conclusion.Results:The total damage score of the foam sclerosant groups was significantly higher than that of the control group(P=0.025).Considering the variables of concentration between groups,the highest damage score was achieved by 3%foam sclerosants(median 3,P=0.043).The highest damage score was achieved by 10min regarding the variables of time.No significant difference was found among the 0.5%and 1%concentrations of sclerosant(P=0.072).There was no significant difference between 1s and control group(P=0.158).In addition,the total damage score of the group of 30s,lmin,5min and lOmin was not significant in statistics(P30s-1min=0.074,P30s-5min=0.071,P30s-10min=0.065,P1min-5min=0.085,P1min-10min=0.142,P5min-10min=0.183).Conclusion:Significant pathological damage can be caused by even the lowest dose of foam sclerosants(0.5%).The most injurious concentration was found to be 3%polidocanol morphologically.The effect of polidocanol stepped into platform 30s after onset.There was no significant difference between groups of 1min,5min and 10min,although the total damage score increased gradually.Further in-vivo studies are needed to validate these findings.