Air versus Physiological Gas for Ultrasound Guided Foam Sclerotherapy Treatment of Varicose Veins

Migraine aura-like episodes following sclerotherapy for varicose veins of the lower extremities-A systematic review

OBJECTIVE

This systematic review provides a summary and evaluation of cases of migraine aura-like episodes elicited by sclerotherapy of veins of the lower extremities and discusses possible underlying mechanisms.

BACKGROUND

Sclerotherapy is a commonly used treatment for varicose veins. Symptoms resembling migraine aura have been reported during and following sclerotherapy of the lower extremities, suggesting that sclerotherapy may elicit migraine aura.

METHODS

We searched PubMed for articles reporting neurological complications that were transient and fully reversible following sclerotherapy treatment for varicose veins in the lower limbs. There were no restrictions regarding article language or publication date. Only original studies and case reports were included. Two authors independently reviewed included articles in detail. Data were extracted from each article, including details on symptoms, previous migraine history, sclerotherapy method, and the presence of a right-to-left cardiac shunt in patients. We evaluated whether episodes fulfilled modified International Classification of Headache Disorders, 3rd edition, criteria for 1.2 Migraine with aura or 1.5.2 Probable migraine with aura.

RESULTS

The search yielded 777 articles, 28 of which were included. Twenty-six articles reported 119 episodes of transient neurological symptoms in 34,500 sclerotherapy sessions. Two additional articles reported six episodes of transient neurological symptoms with no specification of the number of sessions. Of the 125 episodes, 119 involved transient visual disturbances, and eight met the modified criteria for Probable migraine with aura. In most episodes (98%), clinical information was insufficient to determine if the criteria were fulfilled.

CONCLUSIONS

Symptoms that are clinically indistinguishable from migraine with aura attacks may occur following sclerotherapy, although this likely is rare. Microembolization through a right-to-left shunt triggering cortical spreading depolarization is a possible mechanism. Our findings are limited by infrequent specific assessments for neurological complications and a low level of detail in the description of symptoms in the available literature. Future prospective studies are needed to determine this phenomenon's incidence and underlying mechanisms.

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.

Adverse neurological events after sodium tetradecyl sulfate foam sclerotherapy - A prospective, observational study of 8056 treatments

BACKGROUND

Ultrasound guided foam sclerotherapy (UGFS) is a flexible and highly utilised tool in the treatment of varicose veins (VVs), both as a primary treatment and as an adjunct to other treatments. Concern remains regarding the risk of neurological adverse events (AEs) such as migraine, visual disturbance and serious adverse events (SAEs) such as cerebrovascular accident that have been reported after UGFS treatments.

AIM

To determine the incidence of neurological AEs and SAEs after UGFS.

METHODS

A prospective, multicentre, post-authorisation safety study across Europe (both private and government) was performed between January 2015-2020. Neurological adverse events after UGFS with Fibrovein® (Sodium Tetradecyl Sulfate) 1 and 3% physician generated foam.

RESULTS

8056 patients underwent treatment. There were 46 AE (including 5 SAEs), 30 (65%) SAEs were in female patients. Mean age was 55 years with mean body mass index (BMI) of 27. Univariable logistic regression demonstrate that UGFS only treatment (i.e. no adjunctive treatment), liquid-to-gas ratio, gas type and total foam volume (1% sodium tetradecyl sulfate, STS) were significantly associated with the odds of experiencing the outcome. Multivariable logistic regression model exhibits that migraine and total foam volume (1% STS) maintained statistical significance thus associated with the odds of adverse events.

CONCLUSIONS

This study demonstrates that UGFS with Fibrovein is safe with a very low incidence of neurological AEs and SAEs. Past history of migraine, use of physiological gas (O₂/CO₂) and increasing volumes of 1% foam increase the risk of AEs.

Ultrasound-guided foam sclerotherapy is safe and effective in the management of superficial venous insufficiency of the lower extremity

BACKGROUND

Superficial venous disease of the lower extremity has a significant impact on quality of life. Both truncal and tributary vein reflux contribute to this disease process. Endovenous foam sclerotherapy is a widely used technique throughout the world for the management of superficial venous reflux and ultrasound guidance improves its safety and efficacy.

METHODS

A PubMed search for ultrasound-guided foam sclerotherapy (UGFS) was conducted and all abstracts were reviewed to identify clinical trials and systematic reviews for a full-text analysis. Additional articles were also identified through searching the references of the selected studies.

RESULTS

The production of foam for sclerotherapy in a 1:3 or 1:4 ratio of air to sclerosant is optimal in a low silicone, low-volume syringe system. Physiologic gas may decrease any side effects, with the trade-off of decreased foam stability. Proper technique with appropriate sterility and cleansing protocols are paramount for safe and effective treatment. The technical success of UGFS for great saphenous vein disease is inferior to endothermal and surgical modalities and retreatment is more common. However, the clinical improvement in patient-reported quality of life is similar between these three modalities. When used for tributary veins in combination with endothermal approaches of the truncal veins, UGFS has high rates of success with excellent patient satisfaction. UGFS has demonstrated an excellent safety profile comparable with or superior to other modalities.

CONCLUSIONS

With proper technique, UGFS is safe and effective for the management of superficial venous disease.

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.

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.

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.

[Unusual consequences of foam sclerotherapy]

Neurological disorders are rare complications of foam sclerotherapy. Visual disturbances and headache are the most commonly reported events and are thought to be equivalent to migraine with aura. Exceptionally, strokes have been reported. Papillary fibroelastoma is a rare cardiac tumor, which may embolize in cerebral arteries. We report the case of a patient in whom neurological disorders occurred during a session of foam sclerotherapy, and led to the discovery of a cardiac fibroelastoma.

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.

The incidence and characterization of deep vein thrombosis following ultrasound-guided foam sclerotherapy in 1000 legs with superficial venous reflux

OBJECTIVE

The incidence of deep vein thrombosis (DVT) following ultrasound-guided foam sclerotherapy (UGFS) ranges from 0% to 5.7%. The aim of this study was to assess the incidence of DVT following UGFS in a single vascular center.

METHODS

Patients undergoing UGFS between December 2005 and September 2011 underwent quality control duplex imaging within 2 weeks of treatment. This was performed by an independent senior vascular technologist, and data were entered on a prospectively maintained database. Deep venous segments assessed included common femoral vein, femoral vein, above- and below-knee popliteal veins, gastrocnemius, and tibial veins. DVT when present was labeled as endovenous foam-induced thrombosis (EFIT) type 1 when thrombus was lining <25% of the lumen of the deep vein; type 2 when thrombus extension was 25% to 50%; type 3 when thrombus extension was 50% to 99%; and type 4 when the deep vein was occluded.

RESULTS

A total of 1166 UGFS treatments were performed in 1000 legs (776 patients). Complete occlusion of the treated veins was seen in 84.5% of the legs after one session of treatment. Overall, 17 DVTs were detected (1.5%) with no DVTs detected in legs undergoing multiple treatments. Of the 17 episodes of DVT, 16 legs had DVT following treatment for truncal reflux (658 legs; 2.43%). Seven DVTs were EFIT type 1, two were type 2, two were type 3, and five were type 4. One DVT was seen in the gastrocnemius vein alone. Two of 1166 treatments (0.2%) resulted in a symptomatic DVT, both of which were EFIT type 4. On regression analysis, there was an increase in the risk of DVT when ≥10 mL of foam was injected (odds ratio, 4.63; 95% confidence interval, 1.44-14.9; P = .01).

CONCLUSIONS

The incidence of duplex-detected DVT following foam sclerotherapy is low and may be associated with the injection of ≥10 mL of foam.

European guidelines for sclerotherapy in chronic venous disorders

Aim

Sclerotherapy is the targeted chemical ablation of varicose veins by intravenous injection of a liquid or foamed sclerosing drug. The treated veins may be intradermal, subcutaneous, and/or transfascial as well as superficial and deep in venous malformations. The aim of this guideline is to give evidence-based recommendations for liquid and foam sclerotherapy.

Methods

This guideline was drafted on behalf of 23 European Phlebological Societies during a Guideline Conference on 7–10 May 2012 in Mainz. The conference was organized by the German Society of Phlebology. These guidelines review the present state of knowledge as reflected in published medical literature. The regulatory situation of sclerosant drugs differs from country to country but this has not been considered in this document. The recommendations of this guideline are graded according to the American College of Chest Physicians Task Force recommendations on Grading Strength of Recommendations and Quality of Evidence in Clinical Guidelines.

Results

This guideline focuses on the two sclerosing drugs which are licensed in the majority of the European countries, polidocanol and sodium tetradecyl sulphate. Other sclerosants are not discussed in detail. The guideline gives recommendations concerning indications, contraindications, side-effects, concentrations, volumes, technique and efficacy of liquid and foam sclerotherapy of varicose veins and venous malformations.