Invention Of An Ethanol Foam And Invention Of A Marker To End The Making Of Sclerosant Foam

BackgroundVenous malformation is a benign disease of congenital lesions,usually located in the head and neck.It not only affects the beauty,but also has adverse effects on the physiological functions such as swallowing and breathing.In serious cases,it may endanger life due to infection and compression of respiratory tract.Venous malformation has diverse clinical presentations and evolution,the treatment of complex venous malformations has always been a clinical problem and challenge.Its treatment mainly includes surgical resection,sclerotherapy,interventional therapy and so on.Sclerotherapy is an effective treatment for venous malformation,which is widely used in clinic,but it is easy to recur after treatment.Commonly used sclerosants include polidocanol,bleomycin,sodium tetradecyl sulfate,and absolute ethanol.Absolute ethanol has the lowest incidence of lesion re-expansion and the highest rate of severe complications.It is difficult to handle when used in clinic.ObjectiveTo improve the sclerotherapy of absolute alcohol,we aimed to develop a novel type of foam sclerosant,ethanol foam,to treat venous malformations,which has positive therapeutic effect while significantly slighter complications and lower incidence compared with absolute ethanol.MethodsThe appropriate ethanol concentration range for sclerotherapy was selected by in vitro experiment.Human umbilical vein endothelial cells were used in cell counting kit-8 experiment,the lowest concentration of ethanol with sclerotherapy effect was determined,and the highest concentration of ethanol without thrombosis was selected by blood clotting experiment.Then,a stable ethanol foam was prepared by adding polysorbate 80,egg yolk lecithin and hyaluronic acid and optimizing their ratio.Finally,the efficacy and tolerability of ethanol foam in the treatment of venous malformations were evaluated by in vivo experiments.Using rabbit ear vein as an animal model of venous malformations,the effect and complications of ethanol foam on vascular occlusion were primarily observed.On the basis of animal experiments,clinical trials were carried out to further research the therapeutic effect and tolerance of ethanol foam.ResultsStable ethanol foam was produced,and its positive response and good tolerance were proved in both animal experiments and clinical observation.The appropriate ethanol concentration for sclerotherapy was 30%-60%in vitro.A stable ethanol foam was prepared by using polysorbate 80,egg yolk lecithin and hyaluronic acid in a suitable ratio.In animal experiments,the effect of ethanol foam on vascular occlusion was obvious,and the complication rate was lower than that of absolute ethanol.In clinical trials,patients who received ethanol foam sclerotherapy had achieved good results without serious complications.ConclusionsEthanol foam,a novel type of foam sclerosant,was created for treating venous malformations.BackgroundFoam sclerotherapy is an effective treatment strategy for vascular malformations,the foam blocks the blood flow,preventing the scleroant from being diluted,increasing the contact area between sclerosant and vessel wall,prolonging the contact time,which makes foam sclerotherapy achieve better therapeutic effect.For foam sclerotherapy,its sclerosing power depends on foam stability.The stability of foam is affected by many factors,such as preparation methods,temperature,gas-liquid ratio.The traditional method of foam preparation is Tessari's method,and twenty quick passages have been widely used as an indicator for the most stable state of sclerosants.However,whether taking 20 quick passages is enough for all foam sclerosants to attain their most stable state is unknown.In clinic,we found that the noise in the foam producing process disappeared,but to our best knowledge,no literature had reported this phenomenon before.Objective:The purpose of this article is to study whether the disappearing noise in the foam producing process can be used as an indicator to identify when sclerosing foam producing is completed.Further,to access the application range of these two indicators.MethodsFoam was prepared by Tessari methods.Times of passages and disapearance of noise were used as indicator to prepare different types of bleomycin foam,polidocanol foam,and sodium tetradecylsulfate foam.The stability of foam was verified by the foam half-life and foam appearance observed under microscope,then,the application range was accessed.ResultsThe noise in the preparation of 1%polidocanol could not disappear,and after 20 quick passages the polidocanol foam turned to the most stable state,so the 20 quick passages can be the indicator of completing 1%polidocanol foam.The noise of sodium tetradecylsulfate foam disappeared after 18 passages,because of that,both of 20 quick passages and the disappearing noise can be the indicator of completing sodium tetradecylsulfate foam.As for other foam,the noise disappeared after 40 passages around,the foam produced by which has higer stability than by 20 passages,suggesting that the disappearing noise is a suitable indicator of completing those foam.ConclusionsWe suggest that practitioners choose a different indicator depending on the foam type used.