Modified Tessari Tourbillon technique for making foam sclerotherapy with silicone-free syringes

Introduction

Foam sclerotherapy has now become a recognised treatment for varicose veins, with the recent National Institute for Health and Clinical Excellence (NICE) guidelines recommending it above stripping and only second to endovenous thermal ablation, if that is possible and available. ¹ The most widespread method of making foam for sclerotherapy is the Tessari Tourbillon technique ² using two syringes and a three-way stopcock.

In this method, liquid detergent sclerosant in one syringe is mixed with gas (usually air or CO₂:O₂ mixture) in the second syringe, via a three-way stopcock, sometimes with the stopcock slightly offset to increase turbulence. The foam is made by depressing the plunger of one syringe, forcing sclerosant and gas together in the other syringe and then reversing the motion by pushing on the plunger of the second syringe, forcing the mixture back into the first syringe. This process is repeated several times until a homogenous liquid/gas foam is formed. The foam ends up in one of the syringes after 10 or so passages and the three-way stopcock removed, leaving the foam ready for injecting intravenously either directly via needle or via an intravenous cannula.

The reason foam is used in preference to liquid sclerotherapy is that it displaces the blood from the target vein, increasing the contact time between sclerosant and vein wall and decreasing the inactivation of the active sclerosant by blood. Increasing the longevity of the foam should theoretically improve the results of foam sclerotherapy treatment. On this basis, we investigated several factors that might influence the longevity of foam made in the Tessari Tourbillon method, the results of which have been reported elsewhere. ³

During that study, we confirmed an observation initially made by Lai and Goldman ⁴ that foam made using different types of syringes had significantly different longevities. We took their work a stage further and showed that foam made from sodium tetradecyl sulphate (STS) and air, or CO₂:O₂ mixture, lasted significantly longer when made in silicone-free or ‘2 part’ syringes (Norm-Ject® Luer Lock, Henke Sass Wolf, Tuttlingen, Germany) than that made in standard or ‘3 part’ syringes with a rubber stopper on the plunger (BD Plastipak Luer-Lock, Becton, Dickinson and Company, Oxford, UK). The latter have silicone oil within the syringe barrel as a lubricant.

Although the foam made in the silicone-free syringes showed increased longevity, the absence of lubricant resulted in the plungers starting to stick after several passages of the plunger in the syringe barrel. Thus when the foam was made and deposited into one of the syringes ready for injection, the plunger did not move easily on injection of the foam, sticking frequently during the injection and causing the end of the needle within the vein to move significantly, resulting in extravasation in some smaller diameter veins.

As foam sclerotherapy is more effective in smaller diameter veins rather than those with a larger diameter,^5–7 it is into these smaller diameter veins that foam needs to be injected accurately and without extravasation. Of course, it is possible to place a cannula in the vein before injecting foam to reduce this problem. However, direct intravenous injection via needle either under ultrasound control or under direct vision is quicker and easier, and in our practice is a suitable technique for the majority of smaller diameter veins that need treatment.

Hence as the plungers in the silicone-free syringes move smoothly and easily before multiple passages, we developed a technique where we can make foam using Tessari Tourbillon principles but end up with the foam in a syringe for the intravenous injection that had not been used in the production of the foam and hence retained a smooth action during injection. All three syringes in this technique are silicone-free (HSW Norm-Ject Luer Lock Tip) giving the foam the advantages of increased longevity and this technique also allows non-air gas mixtures such a CO₂:O₂ mixtures to be used easily.

Technique

Three syringes (two larger ‘5 ml’ syringes and one smaller ‘3 ml’ syringe) are connected to 3 three-way stopcocks as in Figure 1. We use a mixture of CO₂:O₂ as the gas portion of the foam rather than air. If air is used, only two of the three-way stopcocks are needed (discarding three-way stopcock ‘D’ and gas tubing ‘G’ in the figure). The three-way stopcock ‘D’ is permanently attached to the gas tubing ‘G’ from the regulator on the gas cylinder (not shown) and is only used as the on/off stopcock for the CO₂:O₂ mixture. OPEN IN VIEWER

Syringe ‘A’ holds 1 ml of STS. Syringe ‘C’ is ultimately going to be the syringe used for injection of the foam. After flushing air out of the system, syringe ‘B’ is attached to three-way stopcock ‘F’ and 3 ml of gas (for a 3:1 ratio) are passed into it (note three-way stopcocks ‘F’, ‘E’ and ‘D’ are all open only to the gas tubing ‘G’ and syringe ‘B’ with stopcocks ‘F’ and ‘E’ turned to exclude syringes ‘C’ and ‘A’ from the system.

The next stage (Figure 2) involves closing off the gas by turning ‘D’ 45° anti-clockwise and connecting the sclerosant containing syringe ‘A’ with the gas containing syringe ‘B’ by turning ‘E’ 90° anti-clockwise. Now ‘B’, ‘E’ and ‘A’ make the Tessari Tourbillon configuration for foam sclerotherapy. OPEN IN VIEWER

When the foam has been made by multiple passages between the syringes, the foam is passed into ‘B’ as shown in Figure 3 (NB: 4 ml of foam as this is a 3:1 mixture of 1 ml STS and 3 ml of gas). Once the foam is in syringe ‘B’, ‘F’ is turned 90° anti-clockwise and the foam is passed to unused syringe ‘C’ (Figure 4). This can be disconnected for immediate injection (Figure 5). OPEN IN VIEWER

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Figure 4.

Three-way stopcock F is turned to connect syringes B and C and foam is transferred into syringe C which has not been involved in the production of the foam.

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Figure 5.

Syringe C is detached and ready for intravenous injection.

Discussion

In August 2013, we completed our studies showing that silicone-free syringes made longer lasting foam than foam made with silicone oil lubricated syringes. ³ Using this information, we introduced silicone-free syringes into our practice as our standard equipment for making foam, initially using the traditional Tessari Tourbillon 2 syringe technique with a three-way stopcock. However, we rapidly ran into problems with plungers sticking during injection of the resultant foam and had an unacceptably high level of extravasation during injections of small veins due to the resulting excessive movement of the needle tip. As such, it became obvious to us that in order to keep the advantage of longer lasting foam from the silicone-free syringes, we would need to find a way of making the foam in the silicone-free syringes and then inject it with a syringe that had not been used during the manufacture of the foam. There may be other silicone-free syringes with Luer locks that would enable a different solution to this issue, but this report shows the way we have solved this problem with the equipment that we have been able to source. Similarly, although we have reported our own technique using the syringes as shown, there is no reason that the technique might not be modified by others to use larger or smaller syringes as they wish.

Wollman ⁸ and Cavezzi and co-workers^9,10 reported how different factors affected the production of foam with detergent sclerosants and both showed that non-silicone ‘2 part’ syringes made better foam than those ‘3 part syringes’ with a rubber stopper on the plunger and silicone lubrication. Wollman also reported in his review that these non-silicone syringes were less smooth to inject with. ⁸ Interestingly, the recommendations from the European guidelines from 2012 (published in 2014) ¹¹ include the rapid production of foam and rapid injection after production, and accept the Tessari three-way stopcock method of producing foam, but do not make any recommendation as to syringe type used over and above ‘smooth-moving, disposable syringes’ which is exactly what the technique presented here is trying to achieve.

In conclusion, our modified Tessari Tourbillon technique allows foam to be made by the Tessari Tourbillon principle using silicone-free syringes with Luer locks to enable the production of longer lasting foam, whilst allowing injection with a previously unused silicone-free syringe to allow smooth injection without the plunger sticking within the syringe barrel.