Benefits of polidocanol endovenous microfoam (Varithena®) compared with physician-compounded foams

The Effect of Pushing Rate on Foam Stability in the Tessari Method

BACKGROUND

The Tessari method is commonly used in sclerotherapy for producing foam, involving 2 syringes pushed back and forth 20 times with the use of a 3-way connector. Many factors affect the foam stability which is crucial for clinical efficacy.

OBJECTIVE

This study aimed to identify the optimal pushing rate which may impact the foam stability.

MATERIALS AND METHODS

Polidocanol (POL) solution (1% and 3%) was used to make sclerosant foam via the Tessari method, with a total of 20 pushes performed at different time durations: 10, 15, 20, 25, 30, 35, and 40 seconds. The foam stability was recorded using foam half-life time (FHT), and the pushing pressure to the syringe was recorded using a self-made electric device. Both FHT and the pressure among different groups were compared respectively.

RESULTS

The FHT was decreased as pushing duration exceeding 20 seconds in POL 1% and 15 seconds in POL 3%. Both the highest FHT and pressure point were located in the 10-second group.

CONCLUSION

It is recommended to complete 20 back-and-forth passages within 10 seconds to create stable foam.

Comparative effectiveness of non-compounded polidocanol 1% endovenous microfoam (Varithena) ablation versus endovenous thermal ablation utilizing a systematic review and network meta-analysis

OBJECTIVE

We compared the effectiveness and safety of polidocanol 1% endovenous microfoam ablation vs endovenous thermal ablation with radiofrequency or laser energy for treatment of venous insufficiency caused by lower extremity truncal vein incompetence via network meta-analysis of published comparative evidence.

METHODS

We conducted a systematic literature review following best practices, including a prospective protocol. We screened studies published in English from 2000 to 2023 for randomized and nonrandomized studies reporting direct or indirect comparisons between polidocanol 1% endovenous microfoam and endovenous thermal ablation. Thirteen studies met our eligibility criteria for the network meta-analysis. The co-primary effectiveness outcomes were the closure rate ≥3 months after procedure and the average change in the Venous Clinical Severity Score. For the subgroup of venous ulcer patients, the ulcer healing rate was the primary effectiveness outcome. The secondary outcomes included safety and patient-reported outcomes. Network meta-analyses were conducted on outcomes having sufficient data. Categorical outcomes were summarized using odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity tests and estimates of network inconsistency were used to investigate the robustness of our meta-analysis.

RESULTS

We found that polidocanol 1% endovenous microfoam was not significantly different statistically from endovenous thermal ablation for venous closure (OR, 0.65; 95% CI, 0.36-1.18; P = .16). Although not the primary aim of the study, the network meta-analysis also provided evidence to confirm our supposition that polidocanol 1% endovenous microfoam was significantly differentiated statistically from physician-compounded foam, with higher odds for vein closure (OR, 2.91; 95% CI, 1.58-5.37; P < .01). A sensitivity analysis using the longest available time point for closure in each study, with a minimum of 12 months of follow-up (median, 48 months; range, 12-72 months), showed results similar to those of the main analysis. No association was found between the risk of deep vein thrombosis and the treatment received. The available data were insufficient for a network meta-analysis of Venous Clinical Severity Score improvement and ulcer healing rates.

CONCLUSIONS

Polidocanol 1% endovenous microfoam was not significantly different statistically from endovenous thermal ablation for venous closure and deep vein thrombosis risk for chronic venous insufficiency treatment, based on a network meta-analysis of published evidence. Polidocanol 1% endovenous microfoam was significantly differentiated statistically from physician-compounded foam, with higher odds of vein closure. A sensitivity analysis found venous closure findings were robust at follow-up intervals of 12 months or greater and for up to 6 years. New evidence meeting the inclusion criteria for this review will be incorporated at regular intervals into a living network meta-analysis.

The Stability of Physician-Compounded Foam is Influenced by the Angle of Connector

BACKGROUND

Foam sclerotherapy is an effective treatment for varicose veins and venous malformations, with its efficacy influenced by foam stability. The methods for preparing physician-compounded foam (PCF) are the double syringe system (DSS) and Tessari method. Few studies have been performed to compare the PCF stability produced by the 2 methods and their mechanisms. We aim to compare the stability of PCF produced by 2 two methods in the same connector and explore the reasons for the difference.

METHODS

Foam was generated by the 2 methods under different circumstances. In the Tessari method, 2 syringes were connected at right angles (90°) by a 3-way tap. In the DSS method, 2 syringes were connected by the same 3-way tap in a straight line (180°). The stability and uniformity of foam produced by the 2 methods were compared using foam half-time and optical microscopy, respectively. Assuming that the difference in foam stability between the 2 methods was related to the angles of a connector, we compared the foam stability when 2 syringes were connected with a plastic connector bent to different angles.

RESULTS

The DSS method could produce more uniform foam with longer foam half-time than the Tessari method, which was related to the angle of the connector.

CONCLUSIONS

The stability of PCF is influenced by the angle of the connector.

The 2023 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part II: Endorsed by the Society of Interventional Radiology and the Society for Vascular Medicine

The Society for Vascular Surgery, the American Venous Forum, and the American Vein and Lymphatic Society recently published Part I of the 2022 clinical practice guidelines on varicose veins. Recommendations were based on the latest scientific evidence researched following an independent systematic review and meta-analysis of five critical issues affecting the management of patients with lower extremity varicose veins, using the patients, interventions, comparators, and outcome system to answer critical questions. Part I discussed the role of duplex ultrasound scanning in the evaluation of varicose veins and treatment of superficial truncal reflux. Part II focuses on evidence supporting the prevention and management of varicose vein patients with compression, on treatment with drugs and nutritional supplements, on evaluation and treatment of varicose tributaries, on superficial venous aneurysms, and on the management of complications of varicose veins and their treatment. All guidelines were based on systematic reviews, and they were graded according to the level of evidence and the strength of recommendations, using the GRADE method. All ungraded Consensus Statements were supported by an extensive literature review and the unanimous agreement of an expert, multidisciplinary panel. Ungraded Good Practice Statements are recommendations that are supported only by indirect evidence. The topic, however, is usually noncontroversial and agreed upon by most stakeholders. The Implementation Remarks contain technical information that supports the implementation of specific recommendations. This comprehensive document includes a list of all recommendations (Parts I-II), ungraded consensus statements, implementation remarks, and best practice statements to aid practitioners with appropriate, up-to-date management of patients with lower extremity varicose veins.

Prospective randomized trial of antithrombotic strategies following great saphenous vein ablation using injectable polidocanol endovenous microfoam (Varithena)

OBJECTIVE

Postablation deep vein thrombosis (DVT) represents a potentially serious complication after Varithena polidocanol endovenous microfoam (PEM) ablation. The following primary outcomes were assessed: whether (1) adjunctive apixaban anticoagulation or (2) mechanical deep venous system (DVS) saline flushing could decrease saphenofemoral junction (SFJ) thrombus extension (postablation superficial thrombus extension [PASTE]) and/or DVT compared with compression alone, after great saphenous vein (GSV) PEM ablation.

METHODS

Varithena 1% PEM ablation patients were randomized to (1) SFJ compression, (2) compression and DVS saline flushing, or (3) compression, DVS saline flushing, and 5 days of postprocedural 5 mg oral apixaban anticoagulation twice daily. Duplex imaging was obtained 7 to 10 days after PEM ablation and PASTE/DVT incidence (primary end point) was compared between groups at this time point.

RESULTS

We treated 304 limbs in 257 patients with PEM. Overall, 103 limbs received SFJ compression (group C, 33.8%), 101 received compression and deep venous flushing (group D, 32.9%), and 100 received compression, deep flush, and anticoagulation (group A, 33.2%). Mean ultrasound follow-up time was 9.7 days (all patients) with a primary GSV closure rate of 92.4%. SFJ PASTE (II-IV) occurred in 0.9%, 1.0%, and 0% (groups C, D, and A, respectively). DVT occurred in 16.7%, 14.7%, and 1.98% (groups C, D, and A; χ², P = .002). Patients in group A receiving apixaban anticoagulation had a significant reduction in DVT compared with patients in group C (1.98% vs 16.7%, χ²; P < .001); likewise, patients in group A had a significantly decreased DVT occurrence compared with group D (14.7% vs 1.98%; χ², P = .00162), whereas patients in groups C and D were not statistically different (16.7% vs 14.7%; χ², P = .60).

CONCLUSIONS

(1) Neither adjunctive DVS flushing nor anticoagulation decreased clinically relevant SFJ PASTE (II-IV) incidence, which remained similarly low across all groups and ranged between 0% and 1%, regardless of adjunctive DVS flushing or anticoagulation. This rate was significantly lower than prior reports (2.3%-4.1%). (2) DVS flushing had no influence on the rate of DVT. Observed PEM-induced DVT incidence using SFJ compression alone or compression with DVS flushing (16.7% and 14.7%, respectively) was significantly higher than prior reports (2.5%-9.6%). This finding may relate to the greater extent of AK/BK GSV territory treated in the present study. (3) Five days of postprocedural oral apixaban anticoagulation, 5 mg given twice daily, significantly decreased DVT occurrence to 1.98%, compared with nonanticoagulated patients (16.7%). This finding is comparable with the DVT rates reported after endovenous thermal ablation (0.7-1.7%). (4) Postprocedural apixaban anticoagulation may have a significant preventive role in decreasing DVT occurrence after PEM ablation.

Foam-in-Vein: Characterisation of Blood Displacement Efficacy of Liquid Sclerosing Foams

Sclerotherapy is among the least invasive and most commonly utilised treatment options for varicose veins. Nonetheless, it does not cure varicosities permanently and recurrence rates are of up to 64%. Although sclerosing foams have been extensively characterised with respect to their bench-top properties, such as bubble size distribution and half-life, little is known about their flow behaviour within the venous environment during treatment. Additionally, current methods of foam characterisation do not recapitulate the end-point administration conditions, hindering optimisation of therapeutic efficacy. Here, a therapeutically relevant apparatus has been used to obtain a clinically relevant rheological model of sclerosing foams. This model was then correlated with a therapeutically applicable parameter-i.e., the capability of foams to displace blood within a vein. A pipe viscometry apparatus was employed to obtain a rheological model of 1% polidocanol foams across shear rates of 6 s^-1 to 400 s^-1. Two different foam formulation techniques (double syringe system and Tessari) and three liquid-to-gas ratios (1:3, 1:4 and 1:5) were investigated. A power-law model was employed on the rheological data to obtain the apparent viscosity of foams. In a separate experiment, a finite volume of foam was injected into a PTFE tube to displace a blood surrogate solution (0.2% w/v carboxymethyl cellulose). The displaced blood surrogate was collected, weighed, and correlated with foam's apparent viscosity. Results showed a decreasing displacement efficacy with foam dryness and injection flowrate. Furthermore, an asymptotic model was formulated that may be used to predict the extent of blood displacement for a given foam formulation and volume. The developed model could guide clinicians in their selection of a foam formulation that exhibits the greatest blood displacement efficacy.

Association of great saphenous vein diameter and clinical severity score after treatment of severe chronic venous insufficiency with foam sclerotherapy

Objectives: to evaluate the association of the greater saphenous vein (GSV) diameter in the treatment of patients with severe chronic venous insufficiency (C6 CEAP classification) with ultrasound-guided polidocanol foam sclerotherapy (UGFS).  Methods: A prospective, descriptive and analytical study of 28 patients (30 limbs) that underwent UGFS. Patients were divided into 2 subgroups by GSV diameter (< 8 mm and ≥ 8 mm). Variables analyzed were ulcer healing, clinical intercurrences, clinical CEAP classification, Venous Clinical Severity Score (VCSS), diameter of the treated vein and presence of occlusion or recanalization by Doppler ultrasound. Patients were analyzed at the 1st, 3rd, and 6th months post-treatment. Results: The average age was 68.7 ± 10.5 years, 23 (82,1%) were women, and the average body mass index was 29.2 kg/m2. Although an improvement in VCSS score was observed during follow-up, no significant intergroup difference was noted. Seventeen (56%) limbs presented occlusion of the treated vein at the 1st month, 11 (36%) at the 3rd month, and 9 (30%) at the 6th month of follow-up. The ulcer healing rate was 56,6%. The average ulcer healing time was 90 days. Three (10%) patients presented with ulcer recurrence at the 6th month.  Survival analysis showed no significant difference in ulcer healing rate between subgroups after one year of follow-up (log-rank, p = 0,178). Conclusion: There was no difference between the subgroups of large and small VSM diameter in terms of symptom severity. However, significant reduction of VCSS and pain relief was observed after foam sclerotherapy.

Treatment of superficial venous insufficiency in a large patient cohort with retrograde administration of ultrasound-guided polidocanol endovenous microfoam versus endovenous laser ablation

OBJECTIVE

To evaluate outcomes among symptomatic patients with superficial chronic venous insufficiency treated with retrograde ultrasound-guided polidocanol endovenous microfoam 1% (PEM) or endovenous laser ablation (EVLA).

METHODS

Retrospective chart review from a single vein center between October 2013 and June 2019. Procedures were performed on 1070 patients with CEAP class 2-6 and symptomatic superficial venous reflux of the great saphenous vein (GSV) or anterior accessory saphenous vein (AASV).

RESULTS

PEM was used for 550 procedures and followed for 43 +/- 13 months and EVLA was used for 520 procedures and followed for 57 +/- 18 months. Following complete treatment, elimination of reflux was documented in 93.5% (514/550) and 92.8% (482/520) of the PEM and EVLA procedures, respectively. During the follow-up period, 18% of patients treated with EVLA returned for additional treatment to address residual symptoms in the affected leg. In C6 patients treated with PEM, 69% (11/16) of ulcers healed in less than one month, compared to 5% (1/21) of patients treated with EVLA. In C4 patients with lesions, resolution of spontaneous bleeding was 100% in both groups. There were no neurological or cardiac adverse events (NCAEs) in the PEM group. Minor complications included asymptomatic DVT (0.5%), 1 common femoral vein thrombus extension, and superficial venous thrombosis (4%) in the Polidocanol Endovenous Microfoam PEM group and asymptomatic DVT (0.8%) and 2 EHITs in the endovenous laser ablation (EVLA) group.

CONCLUSIONS

PEM is comparable in safety and efficacy to EVLA for the treatment of saphenous reflux and associated symptoms. PEM was an effective intervention for most patients with C6 disease. Closure rates in both groups were maintained 36 months post treatment.

Thrombotic complications of superficial endovenous ablation: a contemporary review of thermal and non-thermal techniques

Endovenous ablation has become the preferred means to treat superficial venous insufficiency. Ablative technologies have evolved to include a variety of both thermal and nonthermal techniques. The reported thrombotic complications of endovenous heat induced thrombosis (EHIT) and deep venous thrombosis (DVT) associated with thermal techniques are low (<2% overall). However, the limited data on newer non-thermal technologies suggest these modalities may have thrombotic complication rates upwards of 6%. Additionally, the pathophysiology of thrombotic events related to mechanochemical ablative techniques may differ from EHIT, and thus, may have different implications for management. Described is a case report of a stroke after cyanoacrylate ablation of the great saphenous vein, and a review of the current literature reporting the thrombotic complications associated with current thermal and non-thermal techniques. There exists a need for high volume studies on newer ablative techniques to fully understand their associated thrombotic complications. This review highlights the need for a comprehensive classification system and standard treatment algorithm encompassing of thrombotic complications associated with both thermal and non-thermal ablative techniques.

Foam bubble size is significantly influenced by sclerosant concentration for polidocanol but not sodium tetradecyl sulphate

OBJECTIVES

To determine the effect of liquid gas fraction (LGF), sclerosant type and concentration, and filter use on foam bubble size and count.

METHODS

Sclerosant foam microstructure was investigated using light microscopy for a range of LGFs (1 + 2, 1 + 4 and 1 + 8), for both sodium tetradecyl sulphate (STS) and polidocanol (POL), at a range of concentrations (0.5-3%), with and without the addition of micro-filters. Foam was generated using a modified Tessari method and placed into wells for analysis by light microscopy. Foam microscopic morphology was photographically documented, and bubble diameters and counts were quantified.

RESULTS

Spherical bubbles were observed at lower LGF and a trend towards polyhedral morphology was observed at the higher LGF of (1 + 8). The higher gas content in LGF led to larger but fewer bubbles. POL bubble diameters appeared to be more influenced by concentration than STS with smaller bubbles observed at higher concentrations of POL. The mean bubble diameters were slightly larger for STS than POL at the highest concentration of 3% but smaller at lower concentrations of 1% and 1.5%.

CONCLUSIONS

LGF is the primary determinant of bubble diameter and count. In contrast to STS, POL concentration influences the foam bubble size with smaller bubbles generated at higher concentrations of POL and larger bubbles appearing at low concentrations of this agent.

Characterisation and optimisation of foams for varicose vein sclerotherapy

BACKGROUND

Foam sclerotherapy is the process of using an aqueous foam to deliver surfactant to a varicose vein to damage vein wall endothelial cells, causing the vein to spasm, collapse and ultimately be re-absorbed into the body. Aqueous foams are complex fluids that can exhibit a significant yield stress and high effective viscosity which depend on their composition, particularly the bubble size and liquid fraction.

OBJECTIVE

To characterise the properties of foams used for varicose vein sclerotherapy and determine their effectiveness in the displacement of blood during sclerotherapy.

METHODS

Foams are modelled as yield stress fluids and their flow profiles in a model vein are predicted. Values of the yield stress are determined from experimental data for three different foams using the Sauter mean of the bubble size distribution. Along with the measured liquid fraction of the foams, this information is collected into a Bingham number which entirely characterises the process of sclerotherapy.

RESULTS

Polydispersity in bubble size has a strong effect on the yield stress of a foam and the Sauter mean of the size distribution better captures the effects of a few large bubbles. Reducing the polydispersity increases the yield stress, and a higher yield stress results in a larger plug region moving along the vein, which is more effective in displacing blood. The width of the plug region is proportional to the Bingham number, which also has a quadratic dependence on the liquid fraction of the foam. Assuming typical values for the rate of injection of a foam, we predict that for a vein of diameter 5 mm, the most effective foams have low liquid fraction, a narrow size distribution, and a Bingham number B ≈ 4.5.

CONCLUSIONS

The Sauter mean radius provides the most appropriate measure of the bubble size for sclerotherapy and the Bingham number then provides a simple measure of the efficacy of foam sclerotherapy in a vein of a given size, and explains the ability of different foams to remove varicose veins. Foams containing small bubbles, with a narrow size distribution, and a low liquid fraction are beneficial for sclerotherapy.

Micro-mechanical prediction of the effect of surfactant concentration and external friction on the visco-elasto-plastic response of an aqueous foam

We apply a combination of the Viscous Froth model and a surfactant transfer model [Zaccagnino et al., Phys. Rev. E, 2018, 98, 022801] to predict the rheological response of a two-dimensional dry aqueous foam. The model includes both the effect of friction between the foam and the boundaries of the container and also the dissipative effects on the film interfaces caused by surfactant motion. These dynamics are characterized by two free parameters: the Gibbs elasticity, relating surfactant concentration to interfacial tension, and the mobility of the surfactant molecules on the interfaces. We employ numerical simulations to evaluate the static shear modulus, yield stress and the storage and loss moduli of a foam and investigate the effect of our free parameters on these rheological properties.

A new automated system for the preparation of sclerosant foam: A study of the physical characteristics produced and the device settings required

OBJECTIVES

To determine the quality of sclerosant foam produced with an automated preparation system with multiple combinations of sclerosing agents, gases, and device settings.

METHODS

Single-use mixing capsules filled with air or O₂/CO₂ and polidocanol (0.25, 1, or 3%) or sodium tetradecyl sulfate (0.2 or 1%) were coupled to a customized magnetic stirrer. Stirring speed and time were adjusted between 1500 and 4000 r/min and 30 and 60 s, respectively, and characteristics of the foam produced were measured: half-life, bubble diameter, and gas-to-liquid ratio.

RESULTS

With optimized device settings, the following foam characteristics were obtained: half-life range, 1.4 ± 0.9 to 5.2 ± 0.6 min; bubble diameter, 84 ± 14 to 119 ± 6 µm; and gas-to-liquid ratio, 5:1-7:1. Sodium tetradecyl sulfate foam was quicker to form than polidocanol but faster to degrade. Foams with low sclerosant concentrations and O₂/CO₂ required higher speed and longer time.

CONCLUSIONS

Suitable foam characteristics could be obtained with all combinations of sclerosing agent, concentration, and gas.

Sclerotherapy – How to Achieve a Spectacular Outcome

When performed correctly, sclerotherapy results in fibrous occlusion that is not amenable to recanalization. Paramount to success is adequate contact time of a sclerosant to the endothelial cells to cause sufficient damage to the vein while minimizing side effects. To optimize sclerotherapy results, one needs to choose the right patient and the right vein and then use the proper sclerosing agent and injection techniques. This paper will review current literature on sclerotherapy, as well as tips and tricks to optimize outcome and minimize complications.

Foam-in-vein: A review of rheological properties and characterization methods for optimization of sclerosing foams

Varicose veins are chronic venous defects that affect >20% of the population in developed countries. Among potential treatments, sclerotherapy is one of the most commonly used. It involves endovenous injection of a surfactant solution (or foam) in varicose veins, inducing damage to the endothelial layer and subsequent vessel sclerosis. Treatments have proven to be effective in the short-term, however recurrence is reported at rates of up to 64% 5-year post-treatment. Thus, once diagnosed with varicosities there is a high probability of a permanently reduced quality of life. Recently, foam sclerotherapy has become increasingly popular over its liquid counterpart, since foams can treat larger and longer varicosities more effectively, they can be imaged using ultrasound, and require lower amounts of sclerosing agent. In order to minimize recurrence rates however, an investigation of current treatment methods should lead to more effective and long-lasting effects. The literature is populated with studies aimed at characterizing the fundamental physics of aqueous foams; nevertheless, there is a significant need for appropriate product development platforms. Despite successfully capturing the microstructural evolution of aqueous foams, the complexity of current models renders them inadequate for pharmaceutical development. This review article will focus on the physics of foams and the attempts at optimizing them for sclerotherapy. This takes the form of a discussion of the most recent numerical and experimental models, as well as an overview of clinically relevant parameters. This holistic approach could contribute to better foam characterization methods that patients may eventually derive long term benefit from.

Results of polidocanol endovenous microfoam in clinical practice

BACKGROUND

Initial phase III clinical studies with polidocanol endovenous microfoam (PEM) demonstrated its safety and efficacy in the treatment of superficial venous reflux. In those studies, the primary outcome requirement was to assess the improvement in symptoms related to superficial venous disease. The goal of the present study was to evaluate the efficacy of PEM technology in routine clinical practice-specifically, the closure rates after treatment.

METHODS

We performed an observational study during which data were prospectively collected from 2 vein centers using an electronic database. Patients with CEAP (clinical, etiologic, anatomic, pathophysiologic) class ≥2 and symptomatic superficial axial reflux (great saphenous vein, anterior accessory saphenous vein, and small saphenous vein) were included and followed up prospectively. PEM was used to treat the saphenous vein and varicosities. The CEAP classification was used to classify chronic venous disease, and the venous clinical severity score (VCSS) was applied to measure the disease severity. Pain and discomfort were assessed using a visual analog scale, and the residual veins were assessed by physical examination.

RESULTS

PEM was used to treat superficial reflux in 60 patients. The CEAP classification was C2 for 32 patients, C3 for 14, C4 for 10, and C5 for 4 patients. The average pretreatment VCSS was 7.3. The saphenous vein diameter was 6.5 mm, and the average length was 31 cm. The average volume of PEM used to treat the saphenous veins was 9.3 mL. The closure rate at 3 and 6 months was 93% (54 of 58) and 93% (51 of 55), respectively. The VCSS had improved from 7.3 to 1.4. Complications included 1 case of deep vein thrombosis (1.7%), 5 patients (8.3%) with thrombophlebitis, and 4 patients (6.6%) with skin pigmentation.

CONCLUSIONS

PEM is safe and effective for the treatment of saphenous reflux and varicosities. The early closure rates using PEM were maintained at 6 months and are comparable to the results reported with nonthermal, nontumescent technologies and thermal tumescent technologies.

Sirolimus and propranolol inhibit endothelial proliferation while detergent sclerosants induce endothelial activation, microparticle release and apoptosis in vitro

OBJECTIVES

To investigate the effects of detergent sclerosants, sodium tetradecyl sulphate and polidocanol, on endothelial cell activation and microparticle release and the effects of detergent sclerosants, sirolimus and propranolol, on apoptosis in vitro.

METHODS

Cultured human umbilical vein endothelial cells and murine haemangioendothelioma (EOMA) cell lines were incubated with different concentrations of sodium tetradecyl sulphate and polidocanol, as well as sirolimus and propranolol. Endothelial activation was assessed using flow cytometry for CD62e (E-Selectin), CD54 (ICAM-1), CD105 (endoglin), CD144 (VE-Cadherin), CD146 (MCAM) and the release of endothelial microparticles. Cell proliferation was assessed using [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] and carboxyfluorescein succinimidyl ester assays. Apoptosis was assessed using flow cytometry for lactadherin/propidium iodide staining and for Caspase-3 expression.

RESULTS

Sublytic concentrations of sodium tetradecyl sulphate and polidocanol (0.075%-0.3%) increased the expression of the activation markers CD62e and CD54. The expression of CD105 decreased in sclerosant treated cultured human umbilical vein endothelial cells. Both sodium tetradecyl sulphate and polidocanol induced the release of endothelial microparticles. All agents inhibited cell proliferation. Sodium tetradecyl sulphate and polidocanol-induced apoptosis as evidenced by increased phosphatidylserine exposure and caspase-3 expression, whereas sirolimus and propranolol increased caspase-3 expression only.

CONCLUSION

Sublytic concentrations of detergent sclerosants induce endothelial activation and the release of endothelial microparticles. All agents were anti-proliferative in EOMA cell lines, with sodium tetradecyl sulphate and polidocanol inducing cellular apoptosis.

Recent developments on foaming mechanical and electronic techniques for the management of varicose veins

Introduction: Varicose veins are a common disease, causing significant impairment of quality of life to afflicted individuals. Conventional surgery has represented the traditional treatment for years, with significant post-operative complications. By the end of the 20^th century, novel approaches had been developed to induce biochemical sclerosis into the treated vein in order to exclude it from blood circulation.Areas covered: Foaming techniques for treatment of varicose veins, both clinically-approved methods and those under experimental studies. A brief description of cavitation, which is the basis of microbubbles formation, and an overview of foam properties have been also provided, including a discussion on clinical efficacy and safety profile.Expert commentary: Foam sclerotherapy has rapidly gained popularity since it represents the most minimally invasive and cost-effective procedure in the short term. Several different methods of foam preparation have been described in literature. In general, the foam generation method may affect characteristics such as stability and bubble size distribution, which in turn affect the therapeutic action of foam itself. Therefore, the selection of a suitable foaming technique is of importance for treatment success. Future developments on foaming techniques are expected to make sclerotherapy, already an effective treatment, even safer and more versatile therapeutic procedure.

In vitro and ex vivo evaluation of the biological performance of sclerosing foams

Since the first reports on foam sclerotherapy, multiple studies have been conducted to determine the physical properties and behavior of foams, but relatively little is known about their biological effects on the endothelial cells lining the vessel wall. Moreover, a systematic comparison of the biological performance of foams produced with different methods has not been carried out yet. Herein, a 2D in vitro method was developed to compare efficacy of commercially available polidocanol injectable foam (PEM, Varithena) and physician-compounded foams (PCFs). Endothelial cell attachment upon treatment with foam was quantified as an indicator of therapeutic efficacy, and was correlated with foam physical characteristics and administration conditions. An ex vivo method was also developed to establish the disruption and permeabilisation of the endothelium caused by sclerosing agents. It relied on the quantitation of extravasated bovine serum albumin conjugated to Evans Blue, as an indicator of endothelial permeability. In our series of comparisons, PEM presented a greater overall efficacy compared to PCFs, across the different biological models, which was attributed to its drainage dynamics and gas formulation. This is consistent with earlier studies that indicated superior physical cohesiveness of PEM compared to PCFs.

Physical Vein Models to Quantify the Flow Performance of Sclerosing Foams

Foam sclerotherapy is clinically employed to treat varicose veins. It involves intravenous injection of foamed surfactant agents causing endothelial wall damage and vessel shrinkage, leading to subsequent neovascularization. Foam production methods used clinically include manual techniques, such as the Double Syringe System (DSS) and Tessari (TSS) methods. Pre-clinical in-vitro studies are conducted to characterize the performance of sclerosing agents; however, the experimental models used often do not replicate physiologically relevant physical and biological conditions. In this study, physical vein models (PVMs) were developed and employed for the first time to characterize the flow behavior of sclerosing foams. PVMs were fabricated in polydimethylsiloxane (PDMS) by replica molding, and were designed to mimic qualitative geometrical characteristics of veins. Foam behavior was investigated as a function of different physical variables, namely (i) geometry of the vein model (i.e., physiological vs. varicose vein), (ii) foam production technique, and (iii) flow rate of a blood surrogate. The experimental set-up consisted of a PVM positioned on an inclined platform, a syringe pump to control the flow rate of a blood substitute, and a pressure transducer. The static pressure of the blood surrogate at the PVM inlet was measured upon foam administration. The recorded pressure-time curves were analyzed to quantify metrics of foam behavior, with a particular focus on foam expansion and degradation dynamics. Results showed that DSS and TSS foams had similar expansion rate in the physiological PVM, whilst DSS foam had lower expansion rate in the varicose PVM compared to TSS foam. The degradation rate of DSS foam was lower than TSS foam, in both model architectures. Moreover, the background flow rate had a significant effect on foam behavior, enhancing foam displacement rate in both types of PVM.

Retrograde administration of ultrasound-guided endovenous microfoam chemical ablation for the treatment of superficial venous insufficiency

OBJECTIVE

This study measured patient outcomes among symptomatic patients with superficial chronic venous insufficiency who were treated with retrograde ultrasound-guided polidocanol microfoam 1% in a community setting.

METHODS

Between March 2015 and June 2017, 250 symptomatic patients with C2-C6 chronic venous insufficiency received polidocanol microfoam 1% and were followed for 16 ± 7 months. Sixteen of the 250 patients (6.4%) had skin ulcers, and 56 (22.4%) were treated previously with thermal or surgical interventions. All patients underwent a duplex ultrasound venous incompetence study to map perforators and veins to be treated. Incompetent veins were accessed with a micropuncture needle distal to the midthigh perforator, approximately 10 cm above the knee fold. The leg was then elevated 45°. Under ultrasound guidance, the incompetent greater saphenous vein was closed with polidocanol microfoam 1%. A second injection was administered through the same catheter directing the microfoam to flow in a retrograde fashion through the incompetent venous valves to the ankle.

RESULTS

All patients completed the initial treatment; 55 (22.0%) required planned secondary treatment during the follow-up period for residual venous reflux in the below-knee greater saphenous vein. Complete elimination of venous valvular reflux and symptom improvement was documented in 236 patients (94.4%). Minor adverse events included asymptomatic deep vein thrombi (n = 2), common femoral vein thrombus extension (n = 1), and superficial venous thrombi (n = 4). Of the 16 patients with skin ulcers, 10 were C6 patients and 80% experienced wound closure within 4 weeks of treatment.

CONCLUSIONS

Retrograde administration of polidocanol microfoam 1% is a safe and effective treatment with important clinical benefit for superficial venous insufficiency in community practice.

Liquid and Foam Sclerotherapy for Spider and Varicose Veins

Sclerotherapy has wide applicability in treating venous disease at every stage of clinical disease. The various sclerosant drugs and formulations each have unique properties, utilities, and side effects. Treating physicians should be aware of the differences between agents, accounting for disease presentation, vein characteristics, and patient comorbidities when selecting the appropriate sclerosing agents. Successful outcomes rely on proper patient evaluation and assessment for contraindications to sclerotherapy. Thorough patient education regarding realistic expectations with sclerotherapy in terms of symptoms relief, recurrence, and improvement in appearance is of chief importance.

Novel developments in foam sclerotherapy: Focus on Varithena® (polidocanol endovenous microfoam) in the management of varicose veins

Scope Varithena® is a recently approved commercially available drug/delivery unit that produces foam using 1% polidocanol for the management of varicose veins. The purpose of this review is to examine the benefits of foam sclerotherapy, features of the ideal foam sclerosant and the strengths and limitations of Varithena® in the context of current foam sclerotherapy practices. Method Electronic databases including PubMed, Medline (Ovid) SP as well as trial registries and product information sheets were searched using the keywords, 'Varithena', 'Varisolve', 'polidocanol endovenous microfoam', 'polidocanol' and/or 'foam sclerotherapy/sclerosant'. Articles published prior to 20 September 2016 were identified. Results Foam sclerosants have effectively replaced liquid agents due to their physiochemical properties resulting in better clinical outcomes. Medical practitioners commonly prepare sclerosant foam at the bedside by agitating liquid sclerosant with a gas such as room air, using techniques as described by Tessari or the double syringe method. Such physician-compounded foams are highly operator dependent producing inconsistent foams of different gas/liquid compositions, bubble size, foam behaviour and varied safety profiles. Varithena® overcomes the variability and inconsistencies of physician-compounded foam. However, Varithena® has limited applications due to its fixed sclerosant type and concentration, cost and lack of worldwide availability. Clinical trials of Varithena® have demonstrated efficacy and safety outcomes equivalent or better than physician-compounded foam but only in comparison to placebo alone. Conclusion Varithena® is a promising step towards the creation of an ideal sclerosant foam. Further assessment in independent randomised controlled clinical trials is required to establish the advantages of Varithena® over and above the current best practice physician-compounded foam.

A multicenter, randomized, placebo-controlled study to evaluate the efficacy and safety of Varithena® (polidocanol endovenous microfoam 1%) for symptomatic, visible varicose veins with saphenofemoral junction incompetence

Objectives

A randomized, placebo-controlled, multicenter study was conducted to evaluate the safety and efficacy of polidocanol endovenous microfoam (1%, Varithena® [polidocanol injectable foam], BTG International Ltd.).

Methods

Patients (n = 77) with symptomatic, visible varicose veins were randomized to treatment with either Varithena 1% or placebo.

Results

Varithena provided greater mean changes from Baseline in patient-reported assessments of symptoms (e.g., heaviness, achiness, swelling, throbbing, itching [HASTI®] score 30.7 points vs 16.7 points, p = 0.0009, primary endpoint; and modified Venous Insufficiency Epidemiological and Economic Study-Quality-of-Life/Symptoms [m-VEINES-QOL/Sym; p < 0.001]), physician-assessed VCSS, and physician- and patient-assessed appearance compared with placebo.

The HASTI score correlated highly with the modified-VEINES-QOL/Sym and Chronic Venous Insufficiency Questionnaire-2 scores (r = 0.7 to > 0.9, p ≤ 0.001). Adverse events included contusion, incision-site hematoma, and limb discomfort. Venous thrombus adverse events were reported as mild and generally resolved without sequelae.

Conclusions

Varithena provided significantly greater symptom relief and improvement in leg appearance compared with placebo. Adverse events were generally mild and transient. (www.clinicaltrials.gov [NCT00758420]).

Interventions for Varicose Veins: Beyond Ablation

OPINION STATEMENT

Minimally invasive endothermal treatments have replaced surgical ligation and stripping in the management of chronic venous insufficiency (CVI) and are now considered the standard of care. Newer techniques have emerged in the last few years in an attempt to further minimize the procedural discomfort associated with endothermal procedures. These new techniques are designed to avoid tumescent anesthesia (TA). These new non-thermal, tumescentless techniques are well tolerated and are shown to result in equivalent outcomes when compared to the thermal ablations. Since there is no data to support the argument that one of these therapies is truly superior to another, selection of a particular thermal or non-thermal technique is dependent on patient and physician preferences. Adoption of a particular non-thermal procedure is also dependent on other factors such as the learning curve, initial setup costs, overall cost-effectiveness and reimbursement. Once the reimbursement issues are resolved and durability is confirmed, these techniques have the potential to become the new standard of care for the management of CVI.

The role of clinically-relevant parameters on the cohesiveness of sclerosing foams in a biomimetic vein model

We have recently reported on the development of a biomimetic vein model to measure the performance of sclerosing foams. In this study we employed the model to compare the commercially-available Varithena(®) (polidocanol injectable foam) 1% varicose vein treatment (referred to as polidocanol endovenous microfoam, or PEM) with physician compounded foams (PCFs) made using different foam generation methods (Double Syringe System and Tessari methods) and different foam formulations [liquid to gas ratios of 1:3 or 1:7; gas mixtures composed of 100% CO2, various CO2:O2 mixtures and room air (RA)]. PCFs produced using the DSS method had longer dwell times (DTs) (range 0.54-2.21 s/cm in the 4 mm diameter vein model) than those of the corresponding PCFs produced by the Tessari technique (range 0.29-0.94 s/cm). PEM had the longest DT indicating the best cohesive stability of any of the foams produced (2.92 s/cm). Other biomimetic model variables investigated included effect of vessel size, delayed injection and rate of plug formation (injection speed). When comparing the 4 and 10 mm vessel diameters, the DTs seen in the 10 mm vessel were higher than those observed for the 4 mm vessel, as the vein angle had been reduced to 5° to allow for foam plug formation. PCF foam performance was in the order RA > CO2:O2 (35:65) ≅ CO2:O2 (65:35) > CO2; PEM had a longer DT than all PCFs (22.10 s/cm) except that for RA made by DSS which was similar but more variable. The effect of delayed injection was also investigated and the DT for PEM remained the longest of all foams with the lowest percentage deviation with respect to the mean values, indicating a consistent foam performance. When considering rate of plug formation, PEM consistently produced the longest DTs and this was possible even at low plug expansion rates (mean 29.5 mm/s, minimum 20.9 mm/s). The developed vein model has therefore demonstrated that PEM consistently displays higher foam stability and cohesiveness when compared to PCFs, over a range of clinically-relevant operational variables.