Polidocanol Research Articles

Multiple Small-Dose Injections Can Reduce the Passage of Sclerosant Foam into Deep Veins During Foam Sclerotherapy for Varicose Veins

Objective To compare the proportion of foam sclerosant that enters deep veins between multiple injections of <0.5 ml foam per injection and a few injections of >0.5 ml foam per injection. Design & methods One hundred and seven patients with superficial venous incompetence were randomised to receive either multiple injections of <0.5 ml 1% polidocanol (POL) -foam (multiple injections) or a few injections of >0.5 ml 1% POL-foam per injection (few injections) for the treatment of varicose tributaries. All patients then received ultrasound-guided foam sclerotherapy for refluxing great saphenous vein (GSV) using 3% POL-foam. Only a single session was allowed per patient in order to standardise treatment. Qualitative ultrasonographic inspection of the foam was carried out during a 5-min period before compression was applied. Post-sclerotherapy surveillance was done at day 3, 2 weeks, 1 month, 3 months, and 6 months. Results Fifty-six limbs in 53 patients were treated with multiple injections and the remaining 56 limbs in 54 patients were treated with a few injections. There were no significant differences in age or male:female ratio between the groups. The mean volume of 1% POL-foam was 2.2 S.D. 0.6 ml (range: 0.7–4.0 ml) in the multiple injections group and 2.5 S.D. 0.6 ml (range: 1.0–4.0 ml) in the few injections group ( p = 0.003). The mean volume of 3% POL was 1.5 ml (range: 0.7–3.0 ml) and 1.4 ml (range: 0.7–3.0 ml), respectively ( p = 0.137). Ultrasonographic inspection immediately after sclerotherapy demonstrated that foam was distributed significantly more commonly in the deep veins of patients treated with a few injections ( p = 0.0003). Two (4%) of the patients treated with a few injections developed migraine during the procedure, but recovered quickly with no further complications. There was no significant difference in the success rate between the groups at 6 months ( p = 0.257). Conclusions These findings suggest that multiple small-dose injections can reduce the amount of foam sclerosant and the risk of foam sclerosant entering the deep veins in patients with superficial venous insufficiency.

The Lytic Effects of Detergent Sclerosants on Erythrocytes, Platelets, Endothelial Cells and Microparticles are Attenuated by Albumin and other Plasma Components in Vitro

Objective To investigate the lytic effects of sodium tetradecyl sulphate (STS) and polidocanol (POL) on erythrocytes, platelets, endothelial cells and platelet-derived microparticle (PDMP) formation in vitro and the potential protective effects of serum albumin and agents such as procaine. Materials and methods The effects of sclerosants were studied in blood samples obtained from normal individuals. Absorbance densitometry was used to assess the lytic effects of sclerosants on blood cells and cultured human microvascular endothelial cells (HMEC) in plasma and in saline. PDMP were quantified by flow cytometry. Results Haemolysis occurred in whole blood at sclerosant concentrations greater than 0.25% for STS and above 0.45% for POL. Similar concentrations of both agents caused platelet and endothelial cell lysis. Both sclerosants released PDMP at low concentrations but destroyed PDMP at higher concentrations. Albumin significantly reduced the lytic effect of both sclerosants on all cells but had a greater inhibitory effect on POL. Protamine at 0.01% had a neutralising effect on STS, whereas procaine and lignocaine showed no such activity. Conclusions Sclerosants at therapeutic concentrations lyse blood cells and endothelial cells in vitro. This effect is strongly reduced by serum albumin possibly contributing towards the low incidence of thromboembolic complications of sclerotherapy.

Prospective randomized efficacy of ultrasound-guided foam sclerotherapy compared with ultrasound-guided liquid sclerotherapy in the treatment of symptomatic venous malformations

To compare the clinical outcome between ultrasound-guided foam sclerotherapy (UGFS) and ultrasound-guided liquid form sclerotherapy (UGLS) in patients with venous malformations (VM). Eighty-nine patients with symptomatic VM were treated with ultrasound-guided sclerotherapy. There were 22 males and 67 females with mean age of 14.5 years. The sclerosing agents used were 1% polidocanol (POL) or 10% ethanolamine oleate (EO). POL was injected predominantly into smaller, superficial lesions, whereas EO was used for large, deeper lesions. Foam sclerosing solution was provided using Tessari's method. Patients were randomized to receive either UGFS or UGLS. Post-sclerotherapy surveillance was done at 6 months after last session using duplex ultrasound. Findings obtained by duplex scanning were divided into four groups: (1) disappeared group: the venous space was occluded and was totally shrunk; (2) partially recanalized group: the venous space was partially recanalized and was partially shrunk; (3) totally recanalized group: the venous space was totally recanalized and returned at the same size; and (4) worsened group: the venous space was totally recanalized and became worse. Forty-nine patients were treated with UGFS and the remaining 40 were treated with UGLS. There were no significant differences in age and men:women ratio. There was no significant difference in the anatomic distribution of VMs between the two groups. The amount of POL was significantly smaller in patients who were treated with UGFS (P = .022). Similarly, there was a significant reduction in the use of EO in patients treated with UGFS (P = .005). The proportion of VM with total disappearance and partial recanalization was significantly higher in patients treated with UGFS (P = .002). No major complications related to sclerotherapy were encountered in both groups. These findings suggest that UGFS could have greater promise compared with UGLS in the treatment of VMs.

In Vitro Effects of Detergent Sclerosants on Coagulation, Platelets and Microparticles

To investigate the in vitro effects of Sodium Tetradecyl Sulphate (STS) and Polidocanol (POL) on clotting tests, clotting factors, platelets and microparticles. Platelet rich (PRP) and platelet poor (PPP) plasmas were incubated with varying concentrations of STS and POL. Clotting tests, platelet/plasma turbidity, and microparticle studies were performed. Specimens were mixed with individual factor deficient plasmas and clotting factor activities were studied. STS at high concentrations (>0.3%) destroyed platelets, microparticles and the clotting factors V, VII and X. It prolonged all clotting tests including prothrombin time (PT), activated partial thromboplastin time (APTT), non-activated partial thromboplastin time (NAPTT), thrombin time (TT), factor Xa clotting time (XACT) and surface activated clotting time (SACT). Higher concentrations of POL were required to achieve some anticoagulant activity. Low sclerosant concentrations shortened XACT and SACT, and induced release of procoagulant platelet derived microparticles. Increased exposure time resulted in increased procoagulant activity. STS at concentrations higher than 0.5% precipitated a complex containing apolipoprotein b and fibrinogen. Detergent sclerosants affect the clotting mechanism by interfering with clotting factor activities, procoagulant phospholipids and platelet derived microparticles. STS has more anticoagulant activity than POL in high concentrations. Low concentration sclerosants demonstrate procoagulant activity.

Urticaria induced by Etoxisclerol® (polidocanol)

Urticaria induced by Etoxisclerol® (polidocanol)

Independent sensitization to polidocanol and trometamol or glycerol within same product

Independent sensitization to polidocanol and trometamol or glycerol within same product

Stability of Foam in Sclerotherapy: Differences between Sodium Tetradecyl Sulfate and Polidocanol and the Type of Connector Used in the Double-Syringe System Technique

Foam sclerotherapy is an increasingly popular modality in the treatment of varicose veins. Worldwide, the most popular agents used are sodium tetradecyl sulfate (STS) and polidocanol (POL). The double-syringe system technique to make foam out of a sclerosing solution and air has received wide attention for its ease and reproducibility. This study examined the possibility that the relative silicone content of various disposable connectors may affect overall foam stability. We also evaluated the differences in the stability of foam between STS and POL. In the first part of the study, one nondisposable stainless steel connector and five disposable plastic connectors were used to create foam from STS 0.50% and air. The procedure was then repeated to produce foam from POL 0.50% and air from each of the six different connector types. As a measure of foam stability, once foam was created with each type of connector, the time required for half of the original volume of sclerosing solution to settle was recorded. In the second part of the study, foam was created with a nondisposable stainless steel connector only and various concentrations of STS and POL. Foam stability was then measured for these different concentrations of sclerosants. The time for sclerosing solution to settle to half of its initial volume was found to vary according to the specific sclerosant and concentration used, with no statistically significant variation based on connector type. The type of connector used in the double-syringe system technique to produce foam for sclerotherapy is not a factor in foam stability. Sclerosing solutions differ in their foaming stability.

Double-Blind Prospective Comparative Trial between Foamed and Liquid Polidocanol and Sodium Tetradecyl Sulfate in the Treatment of Varicose and Telangiectatic Leg Veins

Twenty subjects were treated with either polidocanol (POL) or sodium tetradecyl sulfate (STS) to compare the efficacy and adverse sequelae of each agent. To determine the safety and efficacy of two widely used sclerosing agents. After the exclusion of saphenofemoral junction incompetency, each subject's leg veins were categorized by size (< 1, 1-3, and 3-6 mm in diameter). Each leg was then randomized to be treated with 0.5%, 1%, or 1% foam of POL or 0.25%, 0.5%, or 0.5% foam of STS according to vein size. An independent panel of four physicians, blinded to treatment, performed randomized photographic evaluations obtained pretreatment and 12 weeks post-treatment. Subject satisfaction index and overall clinical improvement assessment were also obtained. An average 83% improvement was noted for all vein sizes in all subjects with both POL and STS after a single treatment. Subjects were satisfied with treatment, regardless of the sclerosing agent used or the vein size treated. There was no statistically significant difference in adverse effects between each group. Both POL and STS are safe and effective sclerosing agents in the treatment of varicose and telangiectatic leg veins. Both are very tolerable and demonstrate similar post-treatment sequelae.

Treatment of Cervicofacial Lymphatic Malformations with OK-432 Sclerotherapy

Lymphatic malformations (LMs) are low-flow congenital lesions that consist of cysts of varying size. Sclerotherapy with intralesional bleomycin and OK-432 has been reported to yield dramatically beneficial results for this disorder. However, inflammation-related symptoms are often seen after treatment with these sclerosing agents. On the other hand, polidocanol (POL) is reportedly associated with fewer allergic and inflammatory reactions. Up to now, however, very few reports have documented the use of POL microfoam for treatment of LMs. This study was performed to assess the efficacy and safety of POL microfoam sclerotherapy for LMs.Between 2003 and 2016, cases were identified from a prospectively compiled database on low-flow congenital vascular malformations before undertaking a retrospective electronic chart review. Patients were included if they had LMs that had been treated by POL microfoam sclerotherapy. The location, size, and type of LMs were assessed using ultrasound and magnetic resonance imaging. Twenty-gauge venous catheters were inserted into the lymphatic space under ultrasound visualization. The LMs were then fully aspirated if they were macrocystic in form. Microfoam composed of 3% POL was then injected under ultrasound guidance. Microcystic LMs were treated by direct injection with POL microfoam under ultrasound guidance. The outcome was assessed by clinical examination combined with findings of postsclerotherapy imaging using ultrasound and magnetic resonance imaging.During a 13-year period, 32 patients met the inclusion criteria. These were 11 (34%) male patients and 21 (66%) female patients with a mean age of 18 years. The LMs were localized to the head and neck (47%), the trunk (38%), and the extremities (15%). The lesions were subdivided into macrocystic (56%), mixed macrocystic and microcystic (31%), and microcystic (13%) LMs. The average lesion size was 6.6 × 4.6 × 3.0 cm. The mean number of treatment sessions was 2.8 (range, 1-15), with a mean foam volume of 4.6 (range, 1-10) mL. Excellent (47%) and moderate (41%) responses were seen in 88% of the patients. Notably, half of the patients achieved excellent or moderate resolution with a single treatment session. Intralesional hemorrhage occurred in four patients (13%) but resolved spontaneously. Only one patient with mixed macrocystic and microcystic LMs developed post-therapy infection. However, the other patients did not develop any post-therapy inflammation-related symptoms, including fever, pain, and marked swelling.Percutaneous sclerotherapy using POL microfoam appears to be safe and effective for treatment of LMs. Ultrasound-guided POL microfoam sclerotherapy should be considered for such lesions, particularly those that are exclusively macrocystic.

Double-Blind Prospective Comparative Trial between Foamed and Liquid Polidocanol and Sodium Tetradecyl Sulfate in the Treatment of Varicose and Telangiectatic Leg Veins

Background Twenty subjects were treated with either polidocanol (POL) or sodium tetradecyl sulfate (STS) to compare the efficacy and adverse sequelae of each agent. Objective To determine the safety and efficacy of two widely used sclerosing agents. Methods After the exclusion of saphenofemoral junction incompetency, each subject's leg veins were categorized by size (< 1, 1–3, and 3–6 mm in diameter). Each leg was then randomized to be treated with 0.5%, 1%, or 1% foam of POL or 0.25%, 0.5%, or 0.5% foam of STS according to vein size. An independent panel of four physicians, blinded to treatment, performed randomized photographic evaluations obtained pretreatment and 12 weeks post-treatment. Subject satisfaction index and overall clinical improvement assessment were also obtained. Results An average 83% improvement was noted for all vein sizes in all subjects with both POL and STS after a single treatment. Subjects were satisfied with treatment, regardless of the sclerosing agent used or the vein size treated. There was no statistically significant difference in adverse effects between each group. Conclusion Both POL and STS are safe and effective sclerosing agents in the treatment of varicose and telangiectatic leg veins. Both are very tolerable and demonstrate similar post-treatment sequelae.

Single-Blind, Randomized Study Comparing Chromated Glycerin, Polidocanol Solution, and Polidocanol Foam for Treatment of Telangiectatic Leg Veins

BACKGROUND A single-blind, randomized, comparative study was performed to evaluate the efficacy of pure chromated glycerin (CG), polidocanol (POL) 0.25% solution, and POL 0.25% foam (Monfreux technique) for treatment of telangiectasias and reticular leg veins. OBJECTIVE To determine the relative efficacy and safety of two sclerosing agents and foam. METHOD Of 150 randomized patients presenting comparable areas (lateral face of thigh) of telangiectasias and reticular leg veins, 147 could be evaluated by photographic assessment, patients' satisfaction score, and pain at injection sites. Internal and external agreement for the photographic assessment was good for two independent blinded experts. RESULTS CG cleared vessels significantly better than POL solution or foam (p < 0.002). The patients' satisfaction score was also higher in the CG group, although the difference did not reach statistical significance. CG was significantly more painful at injection sites. Other side effects were very few, precluding any statistical comparison. Foam was associated with more side effects (microthrombi, matting) than CG or POL solution. Three patients treated with POL foam experienced a transient visual disturbance. CONCLUSION This study shows that CG is superior to POL solution and foam for sclerotherapy of leg telangiectasias.

Polidocanol Microfoam for Vascular Malformations

Treatment of congenital venous malformations is often unsuccessful. Extensive bleeding and lesion recurrence often occur with surgery. Traditional sclerotherapy has had mixed results, the main problem being the rapid dilution of sclerosant in the blood-filled malformation. In this retrospective Spanish study, investigators evaluated the use of polidocanol in microbubbles of carbon dioxide with color-echo-Doppler-ultrasound guidance for sclerosing venous malformations. Of 50 patients …

Sclerosing foam in the treatment of varicose veins and telangiectases: history and analysis of safety and complications.

To review the use of sclerosing foam in the treatment of varicose veins, to describe the different techniques of foam preparation, and to report the complications of our 3-year experience with this treatment. From November 1997 to the end of October 2000, 453 patients were treated with a sclerosing foam for large, medium, and minor varicosities with sodium tetradecylsulfate (STS) or polidocanol (POL). A first group of 257 patients (90 for minor varicosities and 167 for medium to large veins) received a sclerosing foam according to the Monfreux technique. From December 1999 to October 2000, 196 patients were treated with a sclerosing foam prepared according to Tessari's method (36 for minor size veins or teleangectasias and 170 for medium-large veins). Every patient was studied with (color-flow) duplex scanning before and after the treatment and large vein injections were administered under duplex guide. The immediate success rate was 88.1% in the first group for the medium-large veins. In the same districts we registered an early success rate in 93.3% for the patients treated with the Tessari's method. The complication rate (mostly minor complications) was 8.5% in the first group and 7.1% in the second group. The use of sclerosing foam may become an established therapy in the treatment of varicose veins with a high success rate, low cost, and low major complication rate. According to our actual experience and knowledge, the safe amount of foam should not exceed the 3-ml limit, but further advancements could come from standardization of the foam preparation technique.

Regulation of β-Lactamase Synthesis as a Novel Site of Action for Suppression of Methicillin Resistance in Staphylococcus aureus

Nearly all clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) produce beta-lactamase as well as an additional low-affinity penicillin-binding protein called PBP2a or PBP2', the main factor for mediating methicillin resistance. Polidocanol (PDO), a dodecyl polyethyleneoxide ether, resensitizes clinical isolates of MRSA to methicillin; in addition, their resistance to benzylpenicillin (BP) is reduced. The action of PDO is based on the inhibition of the induced syntheses of PBP2a and beta-lactamase. Induction in our study was performed with 2-(2'-carboxyphenyl)benzoyl-6-aminopenicillanic acid (CBAP). Inducible PBP2a production in MRSA strains is under the control of the same regulatory system which is responsible for the induction of beta-lactamase synthesis. BlaR1, a membrane-spanning protein with a penicillin sensor and a signal transducer domain represents the starting point of this induction cascade. Based on its amphiphilic properties, it is likely that the action of PDO is located in the bacterial membrane. Therefore we investigated the possibility that BlaR1 might be the main target for PDO action. We were able to detect the BlaR1 sensor domain in resistant staphylococcal cells even in the noninduced state by fluorography. In a competition assay, CBAP was bound specifically, with a high affinity to the penicillin sensor. Moreover, the binding of CBAP was very stable. As concerns PDO, no significant interaction with the penicillin binding site of BlaR1 was detectable. This is why the BlaR1 transducer domain is thought to be the actual target area of PDO. In this case, PDO would interfere with the transmission of the signal, generated by the receptor binding of CBAP, through the membrane via BlaR1 into the staphylococcal cell. This assumption could be confirmed by the analysis of the concentration-effect relationship, whereafter PDO does not work as a competitive, but as a noncompetitive antagonist of CBAP. Our results demonstrate that BlaR1 could be an attractive new target for the development of new drugs to overcome methicillin resistance.

内視鏡的内痔核結紮術

We develop a new technique for the prolapse and bleeding internal hemorrhoids (Goligher III) such as fiberscopic hemorrhoidal ligation (FHL) . The technique of FHL is as follows. An upper GI tract fiberscope is employed and the scope is retroflexed in the rectum and the hemorrhoids are ligated using Stiegmann-Goff ligator. A one week, 2-3 ml of 1% aethoxysklerol (AS) is injected between every hemorrhoids submucosally. We performed FHL in total of 15 cases and excellent results (complete disappearance of chief complaints) were obtained in 15 cases (100%) . We consider that this new technique allows better visualization and less pain compare to conventional treatment and assumed to be useful in non-oprative hemorrhoidal therapy.

Experimental study on the effects of sclerosants for esophageal varices on blood coagulation, fibrinolysis and systemic hemodynamics.

The effects of five sclerosants used for treating esophageal varices on blood coagulation and fibrinolysis, systemic hemodynamics, and vascular endothelial cells were studied in mongrel dogs. With each sclerosant, hemolysis and a decrease in the platelet count were observed. Changes in the blood coagulation system occurred immediately after sclerosant administration. Prolongation of the PT and APTT and decreases in fibrinogen and alpha 2-PI were seen in the thrombin (TH), sodium tetradecyl sulfate (STS), and ethanolamine oleate (EO) groups. Polidocanol (PO) and absolute ethanol (ET) had less pronounced effects on these systems. A transient decrease in the cardiac index (CI), pulmonary artery pressure (PAP) and pulmonary artery resistance (PAR) was observed with the administration of the sclerosants, especially in the TH and STS groups. Excessive vascular endothelial damage was observed in the ET group, marked damage was seen in the EO and STS groups and slight damage was recorded in the PO and TH groups.

Effects of Sclerosing Agents on the Local Blood Flow of the Mesenteric Vein in Rabbits

Abstract: To investigate the pathophysiology of scleroembolization as a treatment for esophageal varices, studies were made of the effects of the intravenous administration of Aethoxysklerol (AS), Ethanolamine Oleate (EO), ethanol and thrombin on the local blood flow of the mesenteric vein, the systemic hemodynamics and thrombus formation in blood vessels in rabbits.The dosages and concentrations of Aethoxysklerol used were from 0.5 to 2 ml and from 0.5% to 2%, respectively. This was done to ascertain the possible relationships of these variances of Aethoxysklerol on the local blood flow in vessels with a low‐flow and a high‐flow.99% ethanol, 50 U thrombin and 5% Ethanolamine Oleate were also administered into low‐flow and high‐flow vessels in doses of 0.5 ml and 1 ml, respectively.The increase in AS concentration from 0.5% to 2% caused no remarkable changes in the degree of blood flow inhibition in vessels with either a low‐or a high‐flow, but the time required for inhibition was 45–50 min in vessels with a high flow, which was longer than the 25 min necessary in vessels with a low‐flow. The increase in AS dosage from 0.5 to 2 ml was negligible for enhancing the inhibitory effect of the drug upon the blood flow, but the blood flow inhibition was significantly increased in the low‐flow vessels compared with the high‐flow vessels even when the AS was administered in the same volume and concentrations.The AS‐induced changes on the systemic blood pressure were minimal even with high dosages and high concentrations.99% ethanol and thrombin were less effective in blood flow inhibition in both the low‐and the high‐flow vessels. 5% Ethanolamine Oleate when administered in a volume of either 0.5 ml or 1 ml significantly inhibited the flow in the low‐flow vessels as compared to the flow in the high‐flow vessles.On the other hand, when AS was administered with thrombin, the inhibitory effects were accelerated to 88±26% in the low flow vessels and 44±16% in the high‐flow vessels as compared with administration of AS alone in both the low‐flow and the high‐flow vessels, respectively.We concluded that the embolizing effect of AS alone is rather weak, although it is a relatively safe drug. We consider it wise to combine it with thrombin.

Incidence of Side Effects in the Treatment of Telangiectasias by Compression Sclerotherapy: Hypertonic Saline vs. Polidocanol

Two of the most common side effects of sclerotherapy of leg veins are telangiectatic matting (TM), and postsclerosis hyperpigmentation. A random sample of 113 female patients with similar treatment sites of telangiectasias (less than 1 mm in diameter) and venulectasias of 1-2 mm diameter on the legs were treated by sclerotherapy and assessed at 1 and 6 months later for the presence of TM and hyperpigmentation. Patients received treatment with either 23.4% hypertonic saline (HS) alone (N = 74), 1% polidocanol (POL) alone (N = 21), or a comparison treatment with both HS and 1% POL (N = 18). A subgroup of patients received both 1% POL and 0.5% POL (N = 10). The incidence of hyperpigmentation was related both to vessel size and to sclerosing solution; only one patient showed hyperpigmentation in a vessel less than 1 mm, while in 1-2 mm vessels the incidence was 10.9% for HS and 30.7% for 1% POL (p less than .004) at 1 month. At 6 months postsclerotherapy, the incidence of pigmentation was 2% for HS and 7.5% for 1% POL. Both the type and concentration of sclerosing solution affected the incidence of TM; the incidence of TM was 33% for 1% POL, compared to only 13% for HS (p less than .004). At 6 months follow-up, the incidence of TM decreased to 2% for HS and 9% for 1% POL. Ten patients who developed TM with 1% POL were treated subsequently with 0.5% POL and demonstrated no matting. These data indicate that the incidence of side effects was affected by both the concentration and type of sclerosant.

１％ラウロマクロゴール注射薬中のアルデヒド類の微量分析

1% Lauromacrogol (LM) injection as hospital pharmacy product has been used as a sclerosing agent in the treatment of esophageal varices.LM, a polyoxyethylene ether is prepared by the additive polymerization of ethylene oxide with lauryl alcohol, and accordingly the possibility of degradation for sterilization is present.A high-performance liquid chromatographic (HPLC) method was presented for the separation and analysis of aldehydes in LM injection as their 2, 4-dinitrophenylhydrazones (DNPH). In spite of the sterilization of LM injection, FA and acetaldehyde (AA) were confirmed.Aliphatic carbonyl compounds were increased after the sterilization, especially AA was increased more than 20 times. A HPLC system for the determination of FA and AA with DNPH has been presented and this method provides a potentially very selective and sensitive method for the determination of these compounds in LM injection.

Extravascular effects of sclerosants in rabbit skin: a clinical and histologic examination.

Sclerotherapy refers to the injection of a material for the purpose of obliterating a blood vessel. During this procedure a small quantity of sclerosing solution may be unintentionally injected into the tissues surrounding the vessel, either by missing the vessel or leakage of sclerosant upon withdrawal of the needle. Occasionally, the sclerosant may be intentionally injected into an extravascular site in the hope of reducing telangiectatic mats (best described as multiple, grouped, extremely fine telangiectatic vessels). The various sclerosants in use appear to vary in their potential to cause necrosis of perivascular tissues as a complication. This study examines the clinical and histologic effects of the intradermal injection of 0.1 ml of 0.25, 0.5, and 1.0% Aethoxysklerol (AES); 0.5% Sotradecol (SOT); and 23.4% hypertonic saline (HS) in rabbit skin. All three agents produced some clinical necrosis with intradermal injection. AES in all three concentrations produced the least clinical necrosis, no histologic necrosis, and resolved faster than SOT or HS.