Foam sclerotherapy techniques: different gases and methods of preparation, catheter versus direct injection

Guidelines for management of actual or suspected inadvertent intra-arterial injection of sclerosants

BACKGROUND

Inadvertent intra-arterial injection of sclerosants is an uncommon adverse event of both ultrasound-guided and direct vision sclerotherapy. This complication can result in significant tissue or limb loss and significant long-term morbidity.

OBJECTIVES

To provide recommendations for diagnosis and immediate management of an unintentional intra-arterial injection of sclerosing agents.

METHODS

An international and multidisciplinary expert panel representing the endorsing societies and relevant specialities reviewed the published biomedical, scientific and legal literature and developed the consensus-based recommendations.

RESULTS

Actual and suspected cases of an intra-arterial sclerosant injection should be immediately transferred to a facility with a vascular/interventional unit. Digital Subtraction Angiography (DSA) is the key investigation to confirm the diagnosis and help select the appropriate intra-arterial therapy for tissue ischaemia. Emergency endovascular intervention will be required to manage the risk of major limb ischaemia. This includes intra-arterial administration of vasodilators to reduce vasospasm, and anticoagulants and thrombolytic agents to mitigate thrombosis. Mechanical thrombectomy, other endovascular interventions and even open surgery may be required. Lumbar sympathetic block may be considered but has a high risk of bleeding. Systemic anti-inflammatory agents, anticoagulants, and platelet inhibitors and modifiers would complement the intra-arterial endovascular procedures. For risk of minor ischaemia, systemic oral anti-inflammatory agents, anticoagulants, vasodilators and antiplatelet treatments are recommended.

CONCLUSION

Inadvertent intra-arterial injection is an adverse event of both ultrasound-guided and direct vision sclerotherapy. Medical practitioners performing sclerotherapy must ensure completion of a course of formal training (specialty or subspecialty training, or equivalent recognition) in the management of venous and lymphatic disorders (phlebology), and be personally proficient in the use of duplex ultrasound in vascular (both arterial and venous) applications, to diagnose and provide image guidance to venous procedure. Expertise in diagnosis and immediate management of an intra-arterial injection is essential for all practitioners performing sclerotherapy.

Low temperature offers better foam stability

BACKGROUND

The foam's structural longevity, linked to the effectiveness of sclerotherapy, depends on preparation conditions. The factors enhancing the treatment's effectiveness and efficacy are still under discussion.

METHODS

We conducted an in vitro preclinical research, which included 144 independent trials. A total of 8 combinations involving 18 trials were designed according to settings of +4°C and room temperature (20-22°C), liquid-to-air ratios of 1/1 and 1/4, and polidocanol concentrations of 0.5% and 1% using the modified Tessari method. Our study aimed to examine the effect of air ratio, agent temperature, and polidocanol concentration on stability by assessing the foam half-time (FHT) and defining the optimal preparation conditions.

RESULTS

The mean FHT was 117 ± 30.4 s. The longest FHT was in a 1:4 air-to-sclerosant ratio at +4°C, regardless of the sclerosant concentration (for %0.5 mean FHT: 146.2 ± 13.9 s, for % 1 mean FHT: 146.9 ± 18 s). There was a significant interaction among the three variables on FHT (p = 0.001). Temperature emerged as the primary factor (F(1, 136) = 124, p < 0.001, ηp2 = 0.477), with lower temperatures markedly enhancing the longevity (p < 0.001). Preparation at a temperature of 4°C resulted in an extended FHT of 32.5 s compared to 22°C (95% CI: 24.06-41.04 s).

CONCLUSION

The temperature, agent concentration, and gas ratio significantly influence the stability of the physician-compounded foam. The low temperature at +4°C may offer better FHT for sclerotherapy.

Three-year follow-up analysis of automated microfoam preparation system for great saphenous vein incompetence and varicose veins sclerotherapy treatment

BACKGROUND

To describe the treatment of patients with great saphenous vein (GSV) incompetence and varicose veins (VVs), utilizing an Automated Microfoam Preparation System (AMPS, Varixio®, VB Devices, Barcelona, Spain).

METHODS

Adults between January and June 2021 were included. The AMPS system was used for foam preparation. Sclerotherapy treatment followed international recommendations. The primary endpoint was GSV closure rate after 36 months.

RESULTS

164 patients were enrolled. During the 7-day follow-up period, all GSVs showed complete closure, which was maintained at the 1-year mark. No major complications were reported. A cumulative complete GSV recanalization rate of 6.1% and a partial recanalization rate of 26.8% after 36 months were noted. Some patients (9.7%) required additional treatment. A higher BMI was associated with complete recanalization.

CONCLUSION

The AMPS offers an easy-to-use and standardized procedure, potentially enhancing treatment outcomes if compared with manual preparation. Caution is advised when treating obese patients.

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.

Empty vein ablation innovative technique for chronic venous disease treatment: proof of concept and ex-vivo analysis

BACKGROUND

Sclerotherapy is among the mainstays of chronic venous disease treatment, yet its occlusion rate remains suboptimal compared to thermal tumescent techniques. An innovative three-balloons catheter has been developed to allow sclerotherapy in empty vein conditions (empty vein ablation technique, EVA). Aim of this investigation was to describe the EVA technical aspects and related ex-vivo effects on vein wall.

METHODS

Two samples from jugular veins of an adult sheep were treated by EVA or foam sclerotherapy (FS, Tessari method). Primary outcome was the percentage of circumferential intima treated by EVA or FS; secondary outcomes were intima and media thickness modifications after treatment.

RESULTS

Intact circumferential residual intima were 6.07±2.94% and 16.55±0.70% after EVA and FS, respectively (P=0.020). Despite the average intima and media thickness did not differ between treatments, EVA demonstrated a homogenous damage throughout the vein segment, while FS effect was less destructive distally to the injection site, because moving away from the injection site and floating, it has a less contact with internal surface of the vein.

CONCLUSIONS

EVA seems to overcome chemical ablation limits as flushing effect and the increases vein wall/sclerosant agent contact effect compared to FS. Ex-vivo encouraging results need in-vivo validation to evaluate other points like deactivation of sclerosing agent by blood protein and the contact time control between SA and the vein wall. If we have further confirmations in vivo we might think we have a potential higher occlusion rate compared to FS, paving the way for future clinical trials.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

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.

The role of hyaluronic acid in polidocanol foam: An in vitro study

Objective

To study the role of hyaluronic acid (HA) in polidocanol (POL) foam.

Methods

The dose-dependent effect of HA-POL on cultured human umbilical vein endothelial cells (HUVECs) as well as foam stability was evaluated by measuring optical density (OD) values and foam half-life time (FHT), respectively. An in vitro model was utilized for estimating the foam blood-displacement capacity by adopting maximum displacement distance (MDD) and displacement time. A comparison of foam viscosity was also carried out.

Results

The OD values of HUVECs treated with HA first increased and then decreased with the growing dosage of HA while cells treated with HA-POL died. Both FHT and displacement time were prolonged statistically with a gradually enhanced foam viscosity. As to MDD, there were no significant differences.

Conclusions

HA was found to promote HUVECs proliferation slightly, but this was almost negligible when compared to the cell-killing capacity of 1% POL. The viscosity of POL foam was enhanced by HA indicating its positive correlation with both stability and displacement capacity of POL foam.

Treatment of venous malformations with tumescent-assisted sclero-embolic and ablative lasers (SEALs): Safe and effective long-term outcomes

Background

Perivascular infiltration of tumescent anaesthesia (TA) is an essential element of endovenous thermal ablative procedures employed to treat superficial venous disease. In addition to anaesthesia, TA is administered to achieve vessel wall approximation and to protect surrounding structures from thermal damage. However, its role in the treatment of venous malformations (VMs) has not been established.

Objectives

To assess the safety and efficacy of tumescent-assisted thermal and chemical ablative methods in the treatment of VMs.

Methods

Adult and paediatric patients presenting with VMs were treated using a combination of endovenous laser ablation, foam embolo-sclerotherapy and liquid embolisation using n-BCA. All procedures were ultrasound-guided. Treatment outcomes were assessed in early and late follow-ups. To assess the efficacy of TA in achieving vessel wall approximation, cross-sectional lesional diameters were measured by ultrasound, before and after the administration of TA during endovenous procedures.

Results

In a 12 month period, 22 patients recruited in the study presented with 27 VMs which included 23 extra-truncular lesions (16 subcutaneous and seven intramuscular) and four truncular anomalies. On average the subcutaneous lesions measured 5.5 mm (1.9–24.5 mm) in diameter, intramuscular lesions measured 9.2 mm (5.9–15.1 mm) and truncular anomalies measured 4.9 mm (1.2–12 mm) in diameter. Perivascular infiltration of TA resulted in a significant reduction in vessel calibre (90% reduction on average). Intramuscular VMs were less compressible with TA (69.2% reduction) compared to subcutaneous lesions (98% reduction). Truncular anomalies such as the embryonic marginal vein achieved complete approximation (100% reduction). Procedures were safely tolerated with no major complications such as thromboembolism, stroke, nerve damage or tissue necrosis. Most patients had significant clinical as well as ultrasonographic improvement.

Conclusion

Tumescent-assisted endovenous laser ablation and foam sclerotherapy provides safe and effective outcomes in patients with a variety of VMs.

A nutraceutical formulation combined with sclerofoam-assisted laser treatment ameliorates chronic venous insufficiency

Chronic venous insufficiency has a high impact on the healthcare system due to its high incidence worldwide. We performed a study in 30 women with thigh and leg varices due to major saphenous vein valve incontinence with saphenous trunk reflux causing phlebo-lymphoedema to assess the efficacy of sclerofoam-assisted laser treatment combined with nutraceutical administration. The patients underwent endovascular combination sealing of the saphenous trunk with sclerofoam-assisted laser treatment technique into the major saphenous veins under low-volume tumescent anesthesia followed by intraoperative phlebectomies. Post-operatively, the patients received capsules containing Aesculus Hippocastanum, chondroitin sulphate, proanthocyanidins from Pinus pinaster Aiton, proanthocyanidins from Vitis vinifera L., hydrolysed marine collagen and carcinine dihydrochloride for 3 weeks. We evaluated the extracellular fluid volume of the lower limbs using bioimpedance spectroscopy pre- (T0) and post-surgery (T2) (impedance is a vector which is composed of two components, resistance [RES] and reactance [REA)]). In addition, we evaluated the following parameters pre- and post-surgery: pain, heaviness, paresthesia, itching, swelling, daily urine volume output and leg volume. Limb volume was significantly decreased at T2 compared to T0 (p < 0.01). RES and REA were significantly increased at T2 compared to T0 (p < 0.0001 and p < 0.01, respectively). A significant improvement in heaviness, paresthesia, pain, swelling and itch was also observed (all p < 0.0001) while no changes in terms of diuresis occurred. No adverse effects were observed. The present study shows a promising approach to the treatment of chronic venous insufficiency that warrants further clinical studies in larger cohorts of patients.

Treatment of facial hypertrophic capillary malformations with tumescent-assisted sclerotherapy

Facial capillary malformations (CMs) become hypertrophic and nodular overtime and pose great therapeutic challenge. Here, we describe safe and effective use of tumescent-assisted sclerotherapy (TAS) in conjunction with yellow vascular laser (577 nm) for the treatment of HFCMs. Three patients underwent TAS were included in the case series, and complete resolution in nodularity was achieved in all patients with TAS, with no major complications such as skin necrosis, distal embolisation, blindness and neurological adverse events such as stroke or TIA occurred in any patients.

Spectral Properties of Foams and Emulsions

The optical and spectral properties of foams and emulsions provide information about their micro-/nanostructures, chemical and time stability and molecular data of their components. Foams and emulsions are collections of different kinds of bubbles or drops with particular properties. A summary of various surfactant and emulsifier types is performed here, as well as an overview of methods for producing foams and emulsions. Absorption, reflectance, and vibrational spectroscopy (Fourier Transform Infrared spectroscopy-FTIR, Raman spectroscopy) studies are detailed in connection with the spectral characterization techniques of colloidal systems. Diffusing Wave Spectroscopy (DWS) data for foams and emulsions are likewise introduced. The utility of spectroscopic approaches has grown as processing power and analysis capabilities have improved. In addition, lasers offer advantages due to the specific properties of the emitted beams which allow focusing on very small volumes and enable accurate, fast, and high spatial resolution sample characterization. Emulsions and foams provide exceptional sensitive bases for measuring low concentrations of molecules down to the level of traces using spectroscopy techniques, thus opening new horizons in microfluidics.

Comparative analysis of the results of cyanoacrylate ablation and radiofrequency ablation in the treatment of venous insufficiency

BACKGROUND

Varicose vein treatment has shifted to less invasive techniques owing to the complications associated with traditional treatment. The present study was designed to compare the effectiveness of cyanoacrylate ablation (CAA) with radiofrequency ablation (RFA).

METHODS

Patients who had undergone RFA vs CAA (634 vs 246 patients) to treat great saphenous vein (GSV) insufficiency during a 5-year period were included in the present study. The preoperative and postoperative CEAP (clinical, etiologic, anatomic, pathophysiologic) class, symptoms, recurrence, and Doppler ultrasound findings were compared.

RESULTS

All the veins in both groups were occluded at day 5. The 1-month closure rates were 97.3% and 98.7% for RFA and CAA, respectively. The overall postoperative closure rates at 5 years were 93.1% and 91.1% for RFA and CAA, respectively. The postoperative symptoms, CEAP class, and Doppler ultrasound findings were similar in both groups. The 5-year symptom-free survival rates were 73.5% and 72.0% in the RFA and CAA groups, respectively. The venous clinical severity scores had decreased from 5.9 ± 1.2 to 0.9 ± 0.8 and 5.8 ± 0.9 to 0.8 ± 0.6 in the RFA and CAA groups, respectively. The Aberdeen varicose vein questionnaire scores had decreased from 19.7 ± 5.5 to 4.8 ± 1.5 in the RFA group and from 18.9 ± 5.8 to 4.9 ± 1.4 in the CAA group.

CONCLUSIONS

CAA seems to be the ideal treatment for GSV insufficiency because it is suitable for most patients and is nonthermal and nontumescent, with satisfactory results comparable to those with RFA. Long-term outcomes and cost analyses from larger series are required to confirm our findings.

Venous malformations

The often inexorable growth and expansion of congenital vascular malformations can result in substantial morbidity and, in some cases, premature death of these patients. Despite this, patients suffering from such lesions are often erroneously diagnosed and/or inadequately treated, due to a lack of expertise among primary care practitioners as well as specialists. Venous malformations are the most common type of congenital vascular malformations. Over the last two decades management of these lesions has significantly improved, predominantly due to the introduction and implementation of multidisciplinary team concept as well as improvement in diagnostic and treatment modalities. Relatively recently genetic studies are providing more insights into underlying pathophysiological mechanisms responsible for the development and progression of venous malformations and pharmacotherapy is becoming extensively evaluated for safety and efficacy in the treatment of these often challenging vascular lesions.

Management of Venous Malformations

Venous malformations (VMs) are slow-flow, congenital vascular anomalies that are a result of vascular dysgenesis. Clinical presentation and morbidity depend on size, location, and association with other syndromes. VMs are the most common symptomatic vascular anomaly referred for intervention, usually due to thrombosis, swelling, mass effect, functional compromise, or cosmetic concerns. Treatment for larger lesions can be challenging and a multidisciplinary approach involving medical, interventional, and surgical input is critical for comprehensive care. This article will assist the interventional radiologist in patient assessment and will discuss current techniques for treatment, means to minimize adverse events, and expected outcomes.

Evaluation of the efficacy of foam sclerosant after addition of glycerine on human great saphenous vein: histological and immunohistochemical study

INTRODUCTION

Several treatment modalities have been postulated to improve the efficacy of varicose vein treatment. Addition of glycerine to the sclerosing material has been documented to increase its viscosity and subsequently prolong the duration of stability, in addition to the direct sclerosing effect of glycerine. This histological and immunohistochemical study investigated the efficacy of addition of glycerine 72% to sclerotherapy on the human varicose vein.

METHODS

After surgical stripping of great saphenous veins, three equal segments were resected between two clamps. Specimen 1 was injected with saline only, specimen 2 was exposed to foam sclerosant 2%, and specimen 3 was exposed to a mixture of foam sclerosant 2% and glycerine 72%. All segments were left for 5min. Vein segments were then processed for histological and immunohistochemical study.

RESULTS

Microscopically, haematoxylin and eosin-stained specimen 1 showed endothelial swelling, cytoplasmic eosinophilia and pyknotic nuclei. The media showed sarcoplasm vacuolisation and necrosis. Specimen 3 showed hypereosinophilic sarcoplasm of the smooth muscle fibres. Oedema was less evident, with a relative decrease in the thickness of the wall compared with specimen 2. Immunohistochemically, the expression of smooth muscle actin was weak in specimen 3 compared with specimens 1 and 2. Expression of CD31 antibody was much reduced in specimen 2 which showed conserved islands of endothelial cells. By contrast, there was a complete loss of endothelial cells in specimen 3.

CONCLUSION

Addition of glycerine 72% to foam sclerosant has a more damaging effect on human vein wall.

Use of percutaneous foam sclerotherapy with 1.5% sodium tetradecyl sulfate for treatment of a pelvic limb venous malformation in a dog

CASE DESCRIPTION

A 6-year-old 17-kg (37.4-lb) spayed female mixed-breed dog was evaluated because of swelling and intermittent lameness of the right pelvic limb and perianal and vulvar bleeding caused by a suspected arteriovenous malformation.

CLINICAL FINDINGS

The right pelvic limb had a diffuse, raised, cobblestone-like appearance with lameness, edema, and multifocal ulcerations. The abdominal skin had multifocal circular erythematous lesions, the perianal region was erythematous, and the vestibule had superficial distended vessels. Ultrasonography and CT did not reveal the presence of an arteriovenous malformation; however, digital subtraction venography confirmed the presence of a venous malformation (VM) throughout the limb.

TREATMENT AND OUTCOME

A mixture of foam sclerosant (1.5% sodium tetradecyl sulfate) and contrast medium was agitated with air and injected percutaneously into the VM. The dog received an injection of corticosteroid solution, and a soft-padded bandage was applied to the limb for 3 days. Six weeks later, the dog would intermittently hop when running, and the limb was mildly edematous with ecchymotic lesions; the swelling and lameness had improved considerably. Perianal and vulvar bleeding and dilation of the vestibular vessels had resolved. At 21 months after the procedure, examination revealed no right pelvic limb lameness related to the VM; only small cyst-like lesions and edema around the tarsus remained.

CLINICAL RELEVANCE

The favorable clinical outcome for this dog for a 21-month period after treatment of a pelvic limb VM with foam sclerotherapy has suggested that foam sclerotherapy may be used to successfully treat limb VMs in some dogs.

The effect of the calibre and length of needle on the stability of sclerosing foam

OBJECTIVES

Little is known how calibre and length of needles affect the stability of sclerosing foam.

METHODS

Foams were made of 0.5%, 1%, 2% and 3% polidocanol, and 0.2%, 0.5%, 1% and 3% sodium tetradecyl sulfate (STS), which were mixed with air in the proportion of 4:1. These foams were ejected through needles with the length of: 4 mm, 6 mm and 13 mm, and diameter of: 0.26 mm, 0.3 mm and 0.4 mm.

RESULTS

Foams made of more concentrated polidocanol were more stable. Regarding STS an opposite relationship was revealed. Foams made of polidocanol were more stable if ejected through a longer needle, while the length of needle did not significantly affect stability of STS foams. Foams ejected through 0.26 mm diameter needles were very unstable. In the case of 0.5% polidocanol, 0.3x6mm needle provided atypically stable foam.

CONCLUSION

In order to inject maximally stable foam, calibre and length of needle should be taken into account.

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.

Catheter-directed foam sclerotherapy, an alternative to ultrasound-guided foam sclerotherapy for varicose vein treatment: A systematic review and meta-analysis

PURPOSE

Catheter-directed foam sclerotherapy is a new addition to the treatment modalities available for varicose veins. As a modification of ultrasound-guided foam sclerotherapy, catheter-directed foam sclerotherapy has been purported to offer higher complete ablation rates and an improved safety profile. The aim of this study is to appraise the current literature on the outcomes of catheter-directed foam sclerotherapy compared to ultrasound-guided foam sclerotherapy in chronic venous insufficiency.

METHODS

The review of the literature was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data from studies that reported the outcomes of catheter-directed foam sclerotherapy and ultrasound-guided foam sclerotherapy were extracted, to determine the pooled proportion of complete ablation rates, using a random effect meta-analysis model.

RESULTS

A total of 62 studies, involving 3689 patients, were included in the systematic review. Higher rates of complete ablation were reported in catheter-directed foam sclerotherapy compared to ultrasound-guided foam sclerotherapy during the short- and medium-term follow-ups (Relative Risk = 1.06, Relative Risk = 1.15, Relative Risk = 1.19, p < 0.05). Fewer major and minor complications were also reported in patients who underwent catheter-directed foam sclerotherapy (Relative Risk = 0.23, Relative Risk= 0.43-0.76, p < 0.05).

CONCLUSION

Catheter-directed foam sclerotherapy has been demonstrated to have many advantages over ultrasound-guided foam sclerotherapy, offering superior complete ablation rates in the short-, medium- and long-term follow-ups. It also has a better safety profile, conferring a lower risk of major and minor complications. The conclusions should however be viewed in the context of significant limitations imposed by limited study data.

Effects of Hyaluronic Acid on Stability of Bleomycin Foam

BACKGROUND

Bleomycin (BLM) foam sclerotherapy is effective in the treatment of venous malformations (VMs). Foam stability is influenced by factors such as sclerosant concentration, viscosity, and liquid-gas ratio.

OBJECTIVE

To investigate whether hyaluronic acid (HA) could increase the stability of BLM foam and to evaluate the safety and efficacy of HA-BLM foam.

MATERIALS AND METHODS

Experiment: BLM 6.0 IU + human serum albumin (HSA, 2, 1.95, 1.90, and 1.85 mL, respectively) + 1% HA (0, 0.05, 0.10, and 0.15 mL, respectively) + air 6 mL to create foam using the Tessari method. The foam half-life (FHL) was used to evaluate foam stability. Clinical study: Twenty-eight patients with head and neck VMs were enrolled between June 2018 and August 2019 treated by HA-BLM foam to evaluate the safety and efficacy.

RESULTS

The FHL of the BLM foam was 8.46, 8.95, 10.45, and 14.51 minutes, respectively. All patients achieved significant efficacy, and no obvious side effects were observed.

CONCLUSION

Addition of HA could improve the stability of BLM foam.

Modified Method to Increase the Volume and Stability of Bleomycin Foam: An Experimental Study

BACKGROUND

Bleomycin foam is an effective sclerotherapy method for venous malformations. The preparation method is rather complicated, and the volume and stability of the foam are limited.

OBJECTIVE

To modify the currently used method for preparing bleomycin foam, to simplify the preparation procedure, and to produce foam with greater volume and increased stability.

MATERIALS AND METHODS

Experiment 1: 6.0 IU of bleomycin powder was dissolved in different human serum albumin (HSA):saline solution (SS) ratios of 0.5:1.5, 0.75:1.25, 1:1, 1.25:0.75, 1.5:0.5, 1.75:0.25, and 2:0 in volume; then, an air:liquid ratio of 2:1 was used to create foam using the Tessari method. Experiment 2: 6.0 IU of bleomycin was dissolved directly in 2.0 mL of HSA; then, air:liquid ratios of 1:1, 2:1, 3:1, and 4:1 were used to create foam using the Tessari method. The optimum proportions of HSA:SS and air:liquid were screened by comparing the foam half-life (FHL).

RESULTS

Experiment 1: the optimum proportion of HSA:SS was 2:0, and the FHL was 7.5 minutes. Experiment 2: the optimum proportion of air:liquid was 3:1, and the FHL was 9.0 minutes.

CONCLUSION

The modified method is simpler and could produce more stable bleomycin foam with greater volume.

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.

Catheter-directed foam sclerotherapy with tumescence of the great saphenous vein versus ultrasound-guided foam sclerotherapy: A randomized controlled trial

Objectives

To compare the effectiveness of two foam sclerotherapy techniques of the great saphenous vein.

Methods

Fifty subjects with varicose veins, edema, and great saphenous vein incompetence (diameter 6–10 mm) were randomly categorized into two equal groups and were treated with different foam sclerotherapy techniques: A (usual ultrasound-guided) and B (catheter-directed with tumescence). Concomitant phlebectomy was performed in all patients. Patients were seen on days 7 and 28, and at six and 12 months. The primary outcomes were the full success rate of the treated great saphenous vein and the number of patients who required retreatment sessions performed at 28-day follow-up. The secondary-assisted outcomes were the full success rates of the treated great saphenous vein after the retreatment sessions at six- and 12-month follow-up. Secondary outcomes were changes in quality of life and side effects and complications of the intervention. In case of reflux, retreatment sessions were performed at 28 days and six months in both groups.

Results

Full success rate of the treated great saphenous vein was 36% in group A vs. 80% in group B ( p = 0.012) and the number of patients who required retreatment sessions were n = 14 in group A vs. n = 3 in group B at 28-day follow-up ( p = 0.002). Both were statistically significant. At six and 12 months, the success rates were not statistically significant between the groups. Complication rates were similar between the groups. Quality of life improved in both groups with statistical difference ( p < 0.001).

Conclusions

Catheter-directed foam sclerotherapy with tumescence was better than usual ultrasound-guided foam sclerotherapy as it reached higher full success rate of the treated great saphenous vein and as a lower number of patients required retreatment sessions in the short-term. Both methods proved to be safe and improved the quality of life.

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.

Cerebrovascular ischemia following ultrasound-guided foam sclerotherapy

Cerebral ischemia is a very rare and harmful complication of ultrasound-guided foam sclerotherapy for treatment of varicose veins. This case describes a documented cerebrovascular ischemia in Broca’s area following ultrasound-guided foam sclerotherapy. Less than one hour after intravenous injection of 10 ml of sclerosing foam, an otherwise healthy woman experienced aphasia without any other signs of neurological changes. When she arrived home, a complete inability to talk was observed. The event was misdiagnosed by another doctor as an allergic reaction. Next morning she came to the office to report the allergic reaction, where an appropriate diagnosis was made. She recovered just two days after the injection, but signs of recent cerebral ischemia were seen in Broca’s area on magnetic resonance and transesophageal bubble study echocardiogram revealed a patent foramen ovale. Although rare, we must make great effort to prevent these events instead of treating them.

Preliminary Experience With More Stable Polidocanol Foam in Sclerotherapy of Head and Neck Venous Malformations

BACKGROUND

Foam sclerotherapy is an effective treatment strategy for venous malformations (VMs). Stability is one of the characteristics of sclerosant foams that determine the sclerosing power.

OBJECTIVE

To evaluate the clinical outcomes of sclerotherapy with prolonged half-life of hyaluronic acid (HA)-polidocanol (POL) foam for treating head and neck VMs.

MATERIALS AND METHODS

Seventy patients with head and neck VMs were enrolled between October 2013 and January 2015 in Qilu Hospital Shandong University. Sclerotherapy was performed with prolonged half-life POL foam by addition of 0.05% HA. All patients were followed up at 1, 3, and 6 months. Reviews on the site and size of the lesion, times and duration of treatments, therapeutic response, and complications were performed to evaluate the end result.

RESULTS

Sites of lesions included face, bucca, parotid region, neck, tongue, floor of mouth, lip, forehead, palate, and nose. An overall average of 2.5 treatments was required. Total response rate was 100%. "Resolution" was achieved in 21 cases (30%) and a significant response in 49 patients (70%). Immediate swelling was the most common complication. Epidermal extravasation was seen in 1 patient. Mucosal ulcer was observed in 1 patient. No generalized complications occurred.

CONCLUSION

The prolonged half-life of HA-POL foam sclerotherapy of VMs in the head and neck is safe and effective.

Management of Patients With Venous Leg Ulcers: Challenges and Current Best Practice

Introduction It is well documented that the prevalence of venous leg ulcers (VLUs) is increasing, coinciding with an ageing population. Accurate global prevalence of VLUs is difficult to estimate due to the range of methodologies used in studies and accuracy of reporting. (1) Venous ulceration is the most common type of leg ulceration and a significant clinical problem, affecting approximately 1% of the population and 3% of people over 80 years of age (2) in westernised countries. Moreover, the global prevalence of VLUs is predicted to escalate dramatically, as people are living longer, often with multiple comorbidities. Recent figures on the prevalence of VLUs are based on a small number of studies, conducted in Western countries, and the evidence is weak. However, it is estimated that 93% of VLUs will heal in 12 months, and 7% remain unhealed after five years. (3) Furthermore, the recurrence rate within 3 months after wound closure is as high as 70%. (4) (-6) Thus, cost-effective adjunct evidence-based treatment strategies and services are needed to help prevent these ulcers, facilitate healing when they occur and prevent recurrence. The impact of a VLU represents social, personal, financial and psychological costs on the individual and further economic drain on the health-care system. This brings the challenge of providing a standardised leg ulcer service which delivers evidence-based treatment for the patient and their ulcer. It is recognised there are variations in practice and barriers preventing the implementation of best practice. There are patients not receiving appropriate and timely treatment in the initial development of VLUs, effective management of their VLU and preventing recurrence once the VLU has healed. Health-care professionals (HCPs) and organisations must have confidence in the development process of clinical practice guidelines and have ownership of these guidelines to ensure those of the highest quality guide their practice. These systematic judgments can assist in policy development, and decision making, improve communication, reduce errors and improve patient outcomes. There is an abundance of studies and guidelines that are available and regularly updated, however, there is still variation in the quality of the services offered to patients with a VLU. There are also variations in the evidence and some recommendations contradict each other, which can cause confusion and be a barrier to implementation. (7) The difference in health-care organisational structures, management support and the responsibility of VLU management can vary in different countries, often causing confusion and a barrier to seeking treatment. These factors further complicate the guideline implementation process, which is generally known to be a challenge with many diseases. (8).

Effects of Different Mixing Agents on the Stability of Sodium Tetradecyl Sulfate (STS) Foam: An Experimental Study

PURPOSE

To evaluate the effect of air, CO₂ and contrast medium-air on the dwell time (DT) stability of sodium tetradecyl sulfate (STS) foam.

MATERIALS AND METHODS

Three types of foam sclerosants (air-foam, CO₂-foam, contrast-air-foam) were injected eight times into an inclined straight plastic tube (internal diameters 4 mm and 10 mm) filled with a blood substitute. Injections were captured by CCD camera, and images were transferred for digital analysis and calculation of DT.

RESULTS

Contrast-air-foam and air-foam in a 4-mm tube showed 5.6-/3.3-fold greater DT compared to CO₂-foam, respectively (P = 0.001). Contrast-air-foam in a 10-mm tube showed 2.1-fold greater DT compared to CO₂-foam (P = 0.0167).

CONCLUSION

A mixture of air and iodinated contrast improves the stability of STS foam compared to mixtures using only air or CO₂. Further, animal and clinical studies are needed to validate this in vitro result.

Compression with 23 mmHg or 35 mmHg stockings after saphenous catheter foam sclerotherapy and phlebectomy of varicose veins: A randomized controlled study

Objectives

To compare two different medical compression stockings after varicose vein treatment.

Patients and methods

A randomized single-blind controlled study on two compression regimes after saphenous catheter foam sclerotherapy + phlebectomy was performed. After pads and 5 mmHg contention sock, 23 mmHg (group A, Struva 23®) or 35 mmHg (group B, Struva 35®) medical compression stocking was applied 24 h/day for seven days; subsequently 21–23 mmHg medical compression stocking in daytime. Symptoms, compliance, skin findings, and bioimpedance spectroscopy parameters were assessed.

Results

A total of 94 patients (48 and 49 limbs in groups A and B, respectively) were enrolled. Three (T3) and seven (T7) days post-operatively, most symptoms were significantly milder in group B, especially pain and heaviness at T7 and at day 40 (T40). Ambulation, medical compression stocking stability/tolerability and skin healing were significantly better in group B, with p = 0.046, 0.021/0.060, and 0.010, respectively, at T7. Bioimpedance parameters increased at T7 and decreased at T40 in both groups; leg reactance and limb L-Dex improved in group B at T7 and T40, respectively (p = 0.039 and 0.012).

Conclusions

Compression with 23 and 35 mmHg medical compression stocking after catheter foam sclerotherapy + phlebectomy was effective and well tolerated at immediate/short term. Compression with 35 mmHg medical compression stocking provided less adverse post-operative symptoms and better tissue healing. Bioimpedance results confirmed a slightly better edema improvement with 35 mmHg medical compression stocking.

Is catheter-directed foam sclerotherapy more effective than the usual foam sclerotherapy for treatment of the great saphenous vein?

Objective

This retrospective study presents the long-term results of catheter-directed foam sclerotherapy of the great saphenous vein.

Method

From January 2003 to June 2017, 277 patients with varices and great saphenous vein incompetence were treated with echo-guided foam sclerotherapy. Forty-six patients were treated with long-catheters guided by foam sclerotherapy. Foaming was carried out with sodium-tetra-decyl-sulphate.

Results

Results were examined in the two groups: A (long-catheters) and B (other procedures). The median overall follow-up was 52.1 months. In the A-group, the complete occlusion rate was 34/46 pts (73.9%) and partial occlusion was 10/46 (21.7%). In the B-group, respectively, 130/231 (56.2%) and 90/231 (38.9%). Comparisons between groups were statistically significant (p = 0.023; p = 0.021). Failures involved, respectively, 2/46 (4.3%) and 11/231 (4.7%) with no statistical significance. The complication rates were similar in the two groups.

Conclusions

In this long-term experience (median follow-up exceeding four years), foam-guided sclerotherapy of the great saphenous vein with a long-catheter turned out to be more effective than the usual foam-guided sclerotherapy.

Foam sclerotherapy of segments of the saphenous vein with adjuvant hyaluronan compression

Background: Thermal, mechano-chemical and chemical methods of vein closure are increasingly less effective in saphenous veins with diameters above 10 mm. Furthermore, increasing vein size is associated with unpleasant inflammatory reactions, in particular in locations close to sensitive structures like the skin. External compression media are not able to prevent these unwanted sequela in a tolerable way. As a possible solution, perivenous hyaluronan compression was evaluated combined with microfoam sclero-therapy.

Methods: 34 patients (25 f, 9 m, 43–71 yr/o) with saphenous insufficiency (GSV), dia -meters 10.1–23.1 mm (M: 14.1 mm), distance to skin: >10 mm, received a vein lumen compression oft thigh- or calf segments by perivenous injection of a NASHA gel mediated by a coaxial paravenous catheter prior to catheter-applied microfoam sclerotherapy (aethoxysklerol 1 %). Injection of both, hyaluronan and microfoam, were performed during catheter withdrawal. The aim of hyaluronan compression was a 2/3 reduction oft the native vein cross section. For comparison, adjacent segments were compressed with common tumescent fluid. Segments for both modalities had similar diameter and were randomized. Due to department rules, the junction segment was closed with endovenous lasers to warrant elimination of reflux. No textile compression media were applied. Clinical controls including ultrasound were performed after 2, 8, 26 and 54 weeks.

Results: All treated vein segments showed total occlusion after 2 weeks (first visit). The lumen reduction was 54–81 % (M: 68.4 %) in segments with hyaluronan compression and 8–29 % (M: 19.2 %) in segments with tumes-cent fluid. Time needed for hyaluronan compression was 1.1–3.5 min (M: 2.2 min) and for tumescence 0.8–2.7 min (M: 1.8 min) per 10 cm-segment. Clinical investigations up to 8 weeks did not reveal any symptoms, visible inflammations or stainings in segments covered with hyaluronan, while tumescent-compressed segments had such findings in 20/34 cases (58.8 %). Perivenous hyaluronan did not induce any discomfort or side effects during follow-up.

Conclusions: Even large saphenous veins can be effectively and safely treated by microfoam sclerotherapy without any postinterventional symptoms when the vein lumen is reduced by perivenous injection of hyaluronan gel. However, it takes additional interventional effort to achieve this goal. Future applications could also include combinations with thermal or gluing device or support novel foams like Varithena or biomatrix sclerofoam when treating very large veins or venous aneurysms, and furthermore serve in vein shaping fort the purpose of establishing laminar flow or modifying pressure relations (venoplasty).

Size of Sclerosing Foams Prepared by Ultrasound, Mechanical Agitation, and the Handmade Tessari Method for Treatment of Varicose Veins

OBJECTIVES

Sclerotherapy is a therapeutic method used in the treatment of varicose veins and works by occluding damaged blood vessels with a chemical solution. Foam sclerotherapy is an attractive treatment because the results are more effective than those obtained by using liquid sclerosants. However, serious neurologic complications, which are likely related to air embolism, have been reported after treatment with foams generated by the handmade method (Tessari technique) most often used clinically. We present an alternative ultrasonic technique for preparation of sclerosing foams to treat varicose veins.

METHODS

Three methods of foam generation were compared: ultrasound, mechanical agitation, and Tessari techniques.

RESULTS

Optical microscopic analyses showed that low-frequency ultrasound can generate foams with smaller bubble distributions compared to those produced by handmade and mechanical agitation methods: 98% of the bubble population was less than 55 ± 10 μm for sonicated foams (mean ± SD, 19 ± 1.8 μm; maximum bubble size, <138.3 ± 32.5 μm), 196.7 ± 38.2 μm for mechanically agitated foams (mean, 37.1 ± 10.6 μm; maximum bubble size, <350 ± 70.9 μm), and 211.7 ± 20.8 μm for handmade foams (mean, 30.8 ± 3.8 μm; maximum bubble size, <445 ± 32.8 μm).

CONCLUSIONS

Low-frequency ultrasonic foam generation yields smaller bubbles and more uniform size distributions than other investigated methods. These properties may reduce serious adverse events reported for sclerotherapy of varicose veins, increasing the safety of foam treatment.

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.

Polidocanol induced tubal occlusion in nonhuman primates: immunohistochemical detection of collagen I-V

OBJECTIVE

Intrauterine administration of polidocanol foam (PF) can create fallopian tube occlusion in nonhuman primates. The objective of this study was to determine if PF-induced tubal obstructions contain collagen in the extracellular matrix.

STUDY DESIGN

We compared tissue samples of the intramural fallopian tube obtained from previous studies evaluating the effects of intrauterine infusion of 5% PF 2-12 weeks after treatment. Serial sections of the intramural portion of the fallopian tube obtained from representative treated (rhesus macaques, n=7; baboon, n=11) and untreated control (macaque, n=3; baboon, n=5) animals were stained with hematoxylin and eosin to identify tubal occlusion and by immunohistochemistry for collagens Col-I, Col-III and Col-IV. Descriptive results are summarized.

RESULTS

Control animals exhibited histologically normal fallopian tubal epithelium with no staining for Col-1, light staining for Col-III and Col-V in the lamina propria and Col-IV distributed evenly in the extracellular matrix of the lamina propria. Treatment with PF resulted in acute tissue damage confined to the intramural tube; no epithelial damage or occlusion occurred in the tubal isthmus or ampulla. Blockade of the intramural tube demonstrated fibrosis with the epithelium replaced with extracellular matrix that stained strongly for Col-I, Col-III, Col-IV and Col-V. Col-II was undetectable.

CONCLUSION

Tubal blockage induced by PF resulted in loss of normal epithelium and accumulation of collagens Col-I, Col-III, Col-IV and Col-V at the site of obstruction. The presence of dense collagen staining supports the hypothesis that PF infusion creates lasting tubal obstructions.

IMPLICATIONS

This study demonstrates that PF-induced tubal occlusion results in deposition of collagens suggesting the potential for a more lasting blockade. The structural nature of this occlusion supports the development of intrauterine administration of PF as a nonsurgical method of permanent contraception.

Transient neurologic event following administration of foam sclerotherapy

This report describes a complication of symptoms consistent with transient ischemic attack following administration of physician-compounded foam sclerotherapy created with room air. After intravenous administration of 8 cc of foam sclerosant prepared with room air and polidocanol using the Tessari method, an otherwise healthy man experienced transient neurologic changes. Immediately following injection of foam, a dense hemiplegia consistent with interruption of the middle cerebral arterial circulation was observed. The patient’s symptoms resolved completely over approximately 30 min with interventions including Trendelenburg positioning and supplemental oxygen via nasal cannula. PCP foam sclerotherapy with room air administered in typical concentrations, preparations, and volumes may result in severe neurologic events in otherwise healthy individuals. Continued investigation into the potential role of product, gas, volume and technique to identify optimal approaches may further refine the consistency and safety of foam sclerotherapy.

Sclerotherapy is a safe method of treatment of chronic venous disorders in older patients: A prospective and comparative study of consecutive patients

Objectives

An aging population requires evaluation of methods of treatment for older patients. Our objective was to evaluate the indications, practical modalities, safety and tolerability of sclerotherapy in patients 75 years of age and older (group 1) and compare with a control group of patients 18 to74 years of age (group 2).

Method

This observational, multicentre, prospective and comparative study was conducted by the French Society of Phlebology. Each centre collected in 10 to 20 patients ≥75 years of age and an equal number of patients <75 years of age treated by sclerotherapy, the treatment indication, the patient's personal history, the CEAP clinical class, the type of the veins being treated, the characteristics of sclerotherapy and the complications (immediately after treatment and at one-month follow-up).

Results

Population: In total, 418 patients were enrolled in 15 centres: 176 patients in group 1 (mean: 79.4 years) and 242 patients in group 2 (mean: 52.7 years).CEAP clinical classes C4, C5 and C6, history of deep vein thrombosis (12.5%) and superficial vein thrombosis (11.9%), long-term anticoagulant therapy (9.1%) and antiplatelet therapy (16.5%) were more frequent in older patients.All types of veins were treated from saphenous veins to telangiectasias. Sclerotherapy features: There was no difference in concentration of the sclerosing agents. When foam sclerotherapy was used (84% of patients), the injected volume was lower in group 1. Complications: One vasovagal syncope occurred in group 1. One asymptomatic distal deep vein thrombosis, confined to the Medial Gastrocnemius Veins, was reported in both groups at one-month follow-up.

Conclusions

This study shows the feasibility and safety of sclerotherapy in older patients, with no specific complications nor need for special precautions.

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.

Treatment of superficial venous incompetence

Superficial venous incompetence is a common lower limb vascular condition, with venous ulceration representing the most severe sequela of the disease. The treatment of superficial venous incompetence can aid in ulcer healing, and a variety of modalities are available. Successful treatment requires attention to appropriate patient selection and procedural technique.

A new method for using radiopaque sclerosing foam to treat venous malformations

BACKGROUND

Sclerosing foam is recommended to treat venous malformations (VMs). However, determining the precise dosage for satisfactory efficacy and few side effects are still challenging.

OBJECTIVE

To develop a new method of preparing sclerosing foam by adding contrast agent to treat patients with VMs visibly and precisely under radiologic guidance.

MATERIALS AND METHODS

Sclerosant (polidocanol) and contrast agent (iopromide) were mixed to prepare a new sclerosing foam according to Tessari method, and different ratios of the 2 materials were used to study the stability (half-life) of the produced foams. X-ray absorption of the radiopaque foams was observed during patient treatment with digital subtraction angiography (DSA).

RESULTS

The foams generated with the new method demonstrated a high x-ray absorption under DSA. The foam half-life among groups varied. The ratio of iopromide/polidocanol at 1:2 had a significantly longer half-life than the 1:1 or polidocanol-only group. The 1:2 group had a relative high x-ray absorption and was radiopaque to allow visualization of the sclerosing foam and lesion with DSA.

CONCLUSION

Mixing contrast agent with sclerosant to prepare radiopaque foams is a new method for treating complex VMs with DSA, and a ratio of 1:2 is recommend for polidocanol and iopromide.

Improvement of stability of polidocanol foam for nonsurgical permanent contraception

BACKGROUND

Polidocanol foam (PF), used clinically as a venous sclerosant, has recently been studied as a safe and inexpensive means for permanent contraception. Delivering the sclerosant to the fallopian tubes as a foam rather than a liquid increases the surface areas and thus enhances the desired epithelial disrupting activity of the agent. However, the foam is inherently unstable and degrades with time. Therefore, increasing foam stability and thus duration of the agent exposure time could increase epithelial effect while allowing reduction in agent concentration and potential toxicity.

MATERIALS AND METHODS

We studied methods to improve foam properties that might improve safety and efficacy of PF for intrauterine application. Several types of microporous filters adapted to a syringe-based foaming device were used to study the effect of pore structures on the formation of PF. The foam drainage time and bubble size were characterized. The addition of benzalkonium chloride (BZK) to polidocanol was also investigated for its effects on foam characteristics.

RESULTS

A syringe-based foaming device adapted with an inline filter produced smaller bubble PF with a longer foam drainage time. PF generated with a circular pore filter lasts longer than with a noncircular pore filter. The addition of 0.01% of BZK also improved the stability of PF.

CONCLUSION

The stability of PF is affected by the pore characteristics of the filter used for foam generation and enhanced by the presence of a small amount of BZK. The improved foam, if shown to be efficacious in animal models of contraception, could lead to a safe, simple and inexpensive method alternative to surgical contraception.

Characterization of tubal occlusion after transcervical polidocanol foam (PF) infusion in baboons

OBJECTIVE

Our long-term goal is to develop a nonsurgical method of fallopian tubal occlusion for the purpose of permanent contraception. We have previously demonstrated that transcervical administration of 5% polidocanol foam (PF) can create tubal occlusion in macaques but that multiple treatments are required. In this study, we assessed the efficacy of various regimens of PF with and without depomedroxyprogesterone acetate (DMPA) (to control ovarian cycle phase) in the baboon.

STUDY DESIGN

Adult cycling female baboons were evaluated for tubal patency by hysterosalpingography and then received a transcervical infusion of PF with (+) or without (-) an intramuscular injection of DMPA (3.5 mg/kg). Two concentrations of PF were compared: 1% [(+) DMPA, n=5; (-) DMPA, n=3] and 5% [(+) DMPA, n=4; (-) DMPA, n=3]. Controls received (+) DMPA (n=2) or (-) DMPA, (n=3) only. The reproductive tracts were removed 1-3 months after treatment for examination.

RESULTS

No fallopian tubal occlusion was observed in negative controls (±DMPA). Histologic complete tubal occlusion was observed in 3/8 of females treated with 1% PF and in 6/7 treated with 5% PF. Histologic evaluation suggested that 1% PF is associated with prolonged chronic inflammation (more than 2-3 months), while 5% treatment eliminates the epithelial lining, at least focally, and resolves into complete occlusion within 1-2 months. This pattern of complete occlusion was seen in all 4 females that received 5% PF (+DMPA) and in 2/3 that received 5% PF (-DMPA).

CONCLUSION

In a baboon model of transcervical permanent contraception, a single treatment with 5% PF resulted in complete tubal occlusion more reliably (85%) than 1% PF (38%). Cotreatment with DMPA may improve treatment results with 5% PF but requires additional study.

IMPLICATIONS

A finding that a single transcervical treatment with 5% PF can occlude the fallopian tubes of baboon supports further study of this approach as a novel strategy for permanent contraception for women.

Should foam made with physiologic gases be the standard in sclerotherapy?

Objectives

The aim of this paper is to look at the pros and cons of using physiologic gas to produce foam for use in sclerotherapy. With the expanding use of foam sclerotherapy, there have been increased reports of transient neurologic adverse events such as visual disturbance. Although rare, increased numbers of serious adverse events such as transient ischemic attacks (TIAs) and stroke have been described. These events are seen more often in patients who have migraine with aura and those with a right-to-left shunt.

Methods

A literature search of the databases Ovid and Google Scholar was performed for studies looking specifically at neurologic side effects associated with sclerotherapy and use of physiologic foams. Included studies were randomized controlled trials, meta-analyses, review articles, observational studies and case studies.

Results

Although physiologic gases have been shown in several studies to reduce the incidence of visual disturbance, increasing evidence from recent studies suggest endothelin, rather than gas bubbles to be the cause of these side effects. The cause of stroke and TIA has not been proven and occlusion of cerebral arterioles from gas emboli should still be considered. Many authors state that only good quality foam be injected and volumes should be kept low in an attempt to prevent these rare, but potentially serious events. Foam made with physiologic gases are more biocompatible compared to air-based foam and have been found to be at least as effective in sclerotherapy as foam made with room air.

Conclusion

The use of physiologic gases should be considered for those at increased risk of neurologic side effects such as migraineurs with aura and those with a known PFO. Additionally, as there are few disadvantages to the use of physiologic foam, the use of CO2 or CO2/O2 foam should be considered in all patients receiving foam sclerotherapy.