An investigation on the influence of glycerin on sclerosant foam stability

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.

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.

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.

An Optical Method for Immediate Evaluation of Microfoam Stability in Foam Sclerotherapy

OBJECTIVES

The objective of our study was to develop an optical method that instantly evaluates the stability of sclerosing foam, which would enable early predictions of the clinical performance of the foam and reduce the occurrence of clinical side effects.

METHODS

Based on the principle of light scattering, we developed a method to optically test foam stability and verified it experimentally using sodium morrhuate (2 mL; 0.05 g/mL) and carbon dioxide. A self-made foam preparation instrument was used to achieve a preparation speed of 275 mm/s. The liquid-gas ratios were considered as 1:3, 1:4, and 1:5. Curves of illuminance with respect to the drainage rate and decay time were obtained. By fitting the curve, the relationship between foam half-life time (FHT) and foam decay was obtained. Thus, foam stability was evaluated using the initial illuminance value; the foam transfer time was approximately 3 s.

RESULTS

The experimental FHT varies between 205 and 232 s. Illuminance is exponentially related to drainage rate and linearly related with time. FHT can be expressed by the initial illuminance and illuminance curve fitting coefficients. The half-life of the foam decreases as the initial illuminance value increases, for the same sclerosing drug. The suitability of foam stability is determined by the position of the initial value in the chart.

CONCLUSION

Optical methods are feasible for evaluating foam stability over a short period of time. Clinically predicting the stability of freshly prepared foam can reduce number of incidences of further complications. This will promote the development of foam sclerotherapy and provide a basic understanding of the internal mechanical properties of foam.

Development of Glycerol-Rose Bengal-Polidocanol (GRP) foam for enhanced sclerosis of a cyst for cystic diseases

Polycystic kidney disease (PKD) is a common genetic disorder that results in a proliferating and enlarging cyst and ultimately leads to loss of kidney function. Because an enlarged cyst is a primary factor for limited kidney function, the large cyst is surgically removed by laparoscopic deroofing or sclerosant. This a relatively nascent treatment method entails complications and sometimes fail due to the cyst fluid refilling and infection. This study proposes using a more stable and effective polidocanol foam with glycerol and Rose Bengal (GRP form) to prevent cyst regeneration and irritation, which is caused by the required body movement during the treatment. Specifically, the foam retention time and viscosity were increased by adding glycerol up to 10% (w/v). The GRP form inhibited cellular proliferation and disrupted cellular junctions, e-cadherin, and cyst formation, demonstrated by the LDH, Live and Dead, and re-plating culture assays. The GRP foam was shown to be a safe and effective treatment as a commercial grade polidocanol foam form by an in vivo study in which subcutaneously injected mice injected with commercial 3% polidocanol, and the GRP foam showed no difference in inflammation. Thus, this study provides an advanced polidocanol form by adding glycerol and Rose-Bengal to help existing sclerotherapy.

Comparison of the Safety and Efficacy of Foam Sclerotherapy With 1: 2 Polidocanol to Air Ratio Versus 1: 4 Ratio for the Treatment of Reticular Veins of the Lower Extremities

BACKGROUND

Foam sclerotherapy is a common treatment of lower extremity reticular veins. The effect of different liquid-gas ratios on foam stability and efficacy has been controversial.

OBJECTIVE

To evaluate the use of 2 different polidocanol (POL) to air ratios for the treatment of reticular veins of the lower extremities.

METHODS AND MATERIALS

Patients with lower extremity reticular veins were randomized to foam sclerotherapy with POL mixed with 4 mL of room air for one lower extremity or 2 mL for the other lower extremity. All telangiectasias were treated with glycerin immediately after treatment of the reticular veins. Adverse events (AEs) and efficacy were evaluated by both subject and blinded investigator.

RESULTS

Thirty subjects completed the study. No statistically significant difference was seen in AEs between the 2 different POL to air ratios by subject questionnaire and blinded investigator scores at all time points. Subjects and blinded investigator reported a mean improvement between 0% and 50% at Day 21 and 26% to 75% at Day 90, which was not significantly different between groups.

CONCLUSION

Two different POL to air ratios, 1:2 versus 1:4, were similarly safe and efficacious for the treatment reticular veins of the lower extremities.

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.

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.

Properties of polidocanol foam in view of its use in sclerotherapy

Foam sclerotherapy is a widely used method to treat varicose veins disease. It is easy to use and apply, affordable, and has high efficiency that depends on foam stability upon injection. Since sclerotherapy is usually applied in a medical doctor's office, one of the most employed methods to generate foam is based on the Tessari technique which uses pumping cycles of liquid and air in-and-out of a double syringe system. Finally, the produced foam exits through a small orifice (∼2mm) at the output of a three-way valve. The present work shows results regarding the factors that may influence foam stability (liquid to air ratio, type of connector, syringe diameter, number of pumping cycles, etc.) of a commonly used sclerosing agent (polidocanol). Furthermore, an effort is made to evaluate the effect of adding different substances on the stability of polidocanol foams (0.5% w/w) by altering the surface tension or/and the bulk and interfacial rheological properties of the fluids. It is shown that adding small concentrations of nonionic surfactants can increase foam stability with just a very small variation of the mean bubbles size.

Polidocanol foam stability in terms of its association with glycerin

Objectives:

Foam sclerotherapy effectiveness mainly depends on the concentration of the sclerosing agent and foam stability. The objective of this study was to determine if the addition of glycerol at different concentrations contributes to the stability of polidocanol foam.

Materials and methods:

Control Group: 3% polidocanol. Group 1: polidocanol 3% + glycerin 1.66%. Group 2: polidocanol 3% + glycerin 3.3%. Group 3: polidocanol 3% + Glycerin 5%. Tessari standard method. Five recordings were made for each mixture. Early visual liquefaction time and half liquid time decay were recorded in seconds. Microscopic measurement of the foams. Mixtures surface tension measurement (N/m).

Results:

Early visual liquefaction: Control Group: 27 (± 3.11); Group 1: 67.8 (± 6.49); Group 2:48.6 (± 8.2); and Group 3: 35.8 (± 4.49). Half-liquid time: Control: 129.2 (± 11.00); Group 1: 260.4 (±18.99); Group 2: 224.6 (±13.03); and Group 3: 189.2 (±8.52). Bubbles/mm2–diameter–wall thickness: Control: 68–98 μm-7 μm; Group 1: 189–60 μm-9 μm; Group 2: 76–92 μm-12 μm; and Group 3: 49–112 μm-20 μm. Surface tension: Control = 5.54 N/m; Group 1 = 5.45 N/m; Group 2 = 5.35 N/m; and Group 3 = 5.21 N/m.

Conclusions:

Small amounts of glycerin highly increase the stability and quality of polidocanol foam. This simple chemical method is easily reproducible and applicable.