Basal And Clinical Research On Foam Sclerotherapy In Treating Venous Malformations

Background:Venous malformations (VMs) are low-flowing vascular malformations, these diseases are most frequently occurred in the head and neck region, about 40% of VMs located in head and neck area. The treatment of VMs is especially problematic because of VMs are often progressive; they enlarge over time, particularly during the adolescence and often recur after treatment. Because these diseases occur in the head and neck region which can cause cosmetic defects and dysfunction, they are serious diseases that influence patients physically and psychologically as well as daily life. The lesions mainly involve multiple anatomical regions may interfere with normal speech, swallowing and obstruct the airway. For the treatment of VMs in the head and neck region, one of the most common methods is sclerotherapy which has been widely used in clinic.Polidocanol (POL) and sodium tetradecyl sulphate (STS) are two most common sclerosing agent in international during the treatment of VMs and 1% polidocanol is widely used in China. There are enormous reports stated that very satisfactory therapeutic effect had been achieved during the treatment of VMs by injecting POL into the cavity of lesions. Based on clinical observations, in order to gain good therapeutic effect of VMs, increasing drug concentration, volume and number of injections intralesional injection of POL were adopted which lead to the extend of the treatment cycle, increasing the dose, toxicity and the costs of patients. So, it is necessary to make it clear how long time of contaction between the sclerosant and vascular endothelial cells can lead to necrosis and lysis of endothelial cells in treating of VMs and reduce complication and side effect of sclerosing agent, Therefore the therapy of VMs will become precisely in clinical treatment.Objectives:1. To explore the time of contaction between the sclerosant and vascular endothelial cells that lead to death of endothelial cells, venous malformations endothelial cells(VMECs) were treated by 1% POL on different contaction time, t he death of VMECs were observed.2. To explore the contaction time between the sclerosant and veins that lead to death of cells and occlusion of veins, the marginal auricular veins of rabbits were applied as a research object,1% POL injection was injected into the marginal auricular veins and retained in the veins for different time, the marginal auricular veins were obtained for hematoxylin-eosin (HE) staining to observe the changes of veins wall and endothelial cells.Material and Methods:1. The change of VMECs treated by POLExplant culture was adopted previously to obtain primary cells from a surgical resection human VMs tissue and cultured with extra cellular matrix (ECM). Identified the cultured cells with endothelial cell-specific antigen:the rabbit anti-human von willebrand factor (vWF) and rabbit anti-human cluster of differentiation 34 (CD 34) and observed the growth and morphological characteristics of the cultured cells with an inverted phase contrast microscope; VMECs were applied as a research object and treated respectively for 3 s,5 s, 10 s,15 s and 30 s by 1% Lauromacrogol injection; then incubated in ECM to observed the morphological characteristics of changes and growth levels of the cultured cells.1. The sclerosing effect of marginal auricular veins of rabbits treated by Lauromacrogol for different timeAll 33 rabbits were divided randomly into 5 groups (n=8) and one rabbit was used as the control.1% Lauromacrogol injection was injected into the marginal auricular veins of rabbits and retained in the veins for 5 s,10 s,15 s and 1min by application of a clamp at each end of the veins to prevent Lauromacrogol injection from reaching the systemic circulation. The marginal auricular veins were obtained for hematoxylin-eosin (HE) staining on 1 week, 2 weeks,3 weeks,4 weeks after injection respectively. The histopathologic changes of veins wall and endothelial cells were observed.Results:1. The change of VMECs treated by POL for different timeAll group of VMECs treated by 1% Lauromacrogol injection for 5s,10s,15s, and 30s were death:the connection of all VMECs were broken, membranes and nucleus were ruptured and dissolved.2. The histopathological changes of the marginal auricular veins.1) Histopathological changes of marginal auricular veins treated for 5s:1 week endothelial cell became swelling and perivascular tissue became slight edema, after 2 weeks these were no changes in the blood vein, endothelial cell and also perivascular tissue.2) Histopathological changes of marginal auricular veins treated for 10 s:1 week endothelial cell became swelling and perivascular tissue became slight edema, endothelial cell necrosis was seen along the luminal border,2 weeks intimal thickening with prominent widespread necrosis and lysis endothelial cells was be seen,3 weeks intimal thickening became more obvious,4 weeks partial occlusion was seen in vein.3) Histopathological changes of marginal auricular veins treated for 15 s:1 week endothelial cell became swelling and perivascular tissue became obvious edema, endothelial cell necrosis was seen along the luminal border,2 weeks intimal thickening with prominent widespread necrosis and lysis endothelial cells was seen,3 weeks intimal thickening became more obvious, 4 weeks complete occlusion was seen in vein.4) Histopathological changes of marginal auricular veins treated for 1 min:1 week intimal thickening with prominent widespread necrosis and lysis endothelial cells was be seen,2 weeks intimal thickening became more serious than 1 week,3-4 weeks these was blood vessel tissue we could get because the loss of ear cartilage and skin.Conclusions:1. In vitro experiment, VMECs became decease even treated by 1% Lauromacrogol injection for 5s.2. The marginal auricular veins were treated by 1% Lauromacrogol for 15s, after 4 weeks, complete occlusion occurred in the marginal auricular veins.Background:During the treatment of venous malformations (VMs) using foam sclerotherapy, one of the most popular methods to produce foam was the Tessari method which used pumping cycles of liquid and air in-and-out of a double syringe system. In clinical treatment, sclerosing foam was prepared usually by using two 10 ml syringes, however, no more than 10 ml of sclerosing foam could be produced at a time in this way. Tessari method was originally used in the treatment of varicose veins, in most cases of which 10 ml of fresh sclerosing foam might be sufficient. However, this volume might be insufficient in treating some VMs, especially when the region of lesion was extensive. Sufficient fresh sclerosing foam was needed for the treatment of extensive VMs.There were several ways to get more fresh sclerosing foam, for example, producing foam once more, using bigger syringes or more operators and devices to produce simultaneously. However, all these methods had more or less defects. Here, we reported a modified Tessari method by using three 10 ml syringes which could produce more fresh foam at a time; the volume and the stability of foam produced by the two methods were compared. Foam half time (FHT), the time when half of the original liquid sclerosant was reverted to liquid state, was adopted to assess the stability of the foam.Objective:This study aimed to develop a modified Tessari method for producing more sclerosing foam in treatment of extensive venous malformations.Materials and Methods:Sclerosing foam was produced by using Tessari method and the modified Tessari method. The procedure of the later was as follows:prepared foam in a sclerosant-air ratio of 1:4; connected three disposable 10 ml syringes to two medical three-way taps; drawn 4 ml of liquid sclerosant into one syringe and 16 ml averagely of air into the other two; then moved the plungers of all syringes back and forth for 20 times to produce sclerosing foam. The volume and foam half time (FHT) of foam produced by the two methods were compared.ResultsThe average volume of sclerosing foam produced by Tessari method and the modified Tessari method were 9.8 ml and 19.7 ml, and assessed to have statistical difference.The FHT of foam produced by the two methods were 120 s and 150 s, and assessed to have statistical difference.ConclusionsThe modified Tessari method could produce more fresh and stable sclerosing foamObjectivesThis study sought to examine the correlation between the injection velocities of sclerosing foam and the filling status of cavities in venous malformations (VMs).Materials and methodsSclerosing foam was injected into VMs at different velocities in both in vitro model and in vivo lesions. In the in vitro model, when the flowing velocities of the simulated boold were 1.7 mL/s,1 mL/s,0.2 mL/s and 0 mL/s, the sclerosing foam was injected at different velocities into the centre of simulated VMs while a digital camera was used to record the filling status of the simulated VMs. In the in vivo study, sclerosing foam was injected into the VMs at two different velocities (1.7 mL/s and 0.2 mL/s) and the filling status was detected by digital subtraction angiography.ResultsThe average slowest fulfilling velocities of sclerosing foam that could fulfill the VMs cavity in the in vitro model were 0.78 mL/s,0.75 mL/s,0.7 mL/s and 0.73 mL/s, respectively.In the in vivo study, the VMs cavities could be fulfilled at higher velocity of 1.7 mL/s but not at lower velocity of 0.2 mL/s.ConclusionsHigher injection velocity of sclerosing foam could fill the VMs more thoroughly than lower velocity does.