Foam Sclerotherapy Advice
MR PD COLERIDGE SMITH DM FRCS
Consultant Vascular Surgeon
Department of Surgery, Royal Free & UCL Medical School
The Middlesex Hospital, Mortimer Street, London W1N 8AA
p.coleridgesmith@ucl.ac.uk
Foam sclerotherapy – advice – May 2005.
Introduction
In recent years foam sclerotherapy has become a very popular means of treating varicose veins in southern European countries. Northern Europe has lagged behind, in part due to our prejudice against sclerotherapy and in part due to the lack of experience of most surgeons in undertaking sclerotherapy. This document offers some advice on how to learn to perform ultrasound guided foam sclerotherapy in a safe and effective manner. There is no substitute for practice under the supervision of a skilled colleague and I can't teach you to use this technique from a written document. You also have to remember that sclerotherapy can produce severe adverse reactions if used incorrectly. Inadvertent intra-arterial injection is well known to result in the loss of limbs. This has followed ultrasound guided injection as well as the older, blind injection methods. Death may follow allergic reactions to sclerosants but is fortunately rare. However, you must be prepared to deal with this life threatening problem should it arise.
Suitability of veins – what can or can't be treated!?
With enough experience you can treat almost any vein with foam sclerotherapy if required. Some do better than others so the recommendations below are all relative indications and contraindications.
The main criteria relate to size and extent of varices. Problems with thrombophlebitis may occur following foam sclerotherapy and I advise surgery in patients with very large (>10 mm dia) and extensive varices in the thigh especially in obese patients which application of firm bandaging may be difficult. If very large varices are present in the calf this is less of a problem since compression bandaging can be effectively applied in this part of the limb, but this is probably a relative contraindication to treatment by foam sclerotherapy. In the great saphenous vein diameters below 7 mm work well with this technique. In the range 7 – 14 mm occlusion of the vein is easily achieved but the occluded vein may be easily palpable in slim patients. This is usually not a problem in elderly or unfit patients but is a consideration for those in whom the cosmetic outcome is important. Brown discolouration of the skin over the vein may be an issue in some patients. Thrombophlebitis may occur occasionally in the larger veins and I have discussed the management of this problem below. Aspiration of retained thrombus is an excellent method of minimising the problems associated with treating large veins.
For the small saphenous vein I have successfully treated incompetent veins up to 10 mm dia although this technique probably works best in the smaller veins (5 mm dia and below). I have confirmed long term occlusion of the SSV (well, up to 1 year anyway) in several 10 mm dia veins.
I avoid patients who are obese (BMI > 32) since the legs are difficult to bandage and there is an increased risk of DVT. I also think that patients with extensive post-thrombotic deep vein damage should not be treated because of the risk of DVT and limited clinical benefit. For patients with minor post-thrombotic damage or evidence of thrombophlebitis I am concerned about the possibility of a thrombophilia and give one dose of Fragmin at the time of treatment.
Very thin patients may be left with lumps where the veins were obliterated following sclerotherapy and are less suitable for treatment.
Ideal patients to manage with this treatment are those with moderate GSV or SSV varices, principally in the calf where no surgery has been performed previously. These are easy to manage and an excellent outcome is likely. You should start your experience of foam sclerotherapy with these patients.
The patient's expectations are also important. Some are terrified at the thought of surgery and all that goes with it and are very happy to avoid undergoing surgical treatment in hospital. The penalty they pay is that two or three sessions of treatment are required if both legs are to be treated and that this may mean bandaging both limbs following each session. The part of the treatment hated by most patients is the bandaging!! Some patients are keen to avoid any time away from work or commitments at home. Again foam sclerotherapy is ideal in this group. The residual lumps and bruised appearance following sclerotherapy may take several months to resolve and patients should be aware of this before they start. I believe that this summarises the patient type who will succeed with foam sclerotherapy.
The group that does better with surgery are those in a hurry! You can't achieve this with foam and surgery is the best solution for them. This group have a holiday in the sun in 6 weeks and expect you to fix the problem instantly! You can't do it with foam so either another solution is required or they should come back when it is more convenient. This group of patients also usually are happy to undergo surgical treatment, even when you tell them that they will need some time off work and that big bruises may result.
Getting started.
The core skills you need to use ultrasound guided foam sclerotherapy are competence at duplex ultrasonography of the venous system of the lower limb and competence at sclerotherapy. The former is more important – it is essential that you know exactly what problem you are dealing with before injecting foam. You also have to know exactly which vein you are injecting! In the UK vascular surgeons do not commonly learn the skill of venous duplex ultrasonography and this is certainly a disadvantage when trying to start a foam sclerotherapy practice. In other European countries this skill is learned as part of surgical training.
Ultrasound guided canulation.
One of my favourite sports remains watching skilful surgeons trying to put a needle in the vein using ultrasound guidance having never tried this before! After a lot of practice it is very easy but to start with it seems impossible for some. You can buy an ultrasound phantom that aims to teach you how to do this the painless way! This comes from the USA: www.bluephantom.com.
The blue block contains two channels with blood in them. Use this to gain experience putting an 18g canula, a 23g Butterfly and a 25 g needle into the veins.
The ultrasound phantom US guided IV canulation
How to put the needle in the vein.
I prefer to scan the vein in transverse section but you must follow the tip of the needle (only) when using this method. I regularly inject veins of 1 mm dia and less using this strategy and find that it is the most effective.
Use the best ultrasound machine you can obtain – especially when learning. The better the picture the easier this will be. Use a 9 – 12 MHz imaging frequency if possible to help with the image quality. Ensure that the focus is set at the right level in the image and that you have the biggest picture of the vein that you can get.
Select a straight section of vein for canulation. This is easy in patients with primary varicose veins but more difficult to find in cases of recurrent varices. In primary GSV incompetence the best place is just above the knee (for the thigh section) and in the mid-calf when treating calf varices. In primary SSV reflux the best place is 10 – 15 cm below the SPJ.
Anaesthetise the skin with a small volume (0.25 ml) of lignocaine injected into the skin when using an 18 g canula. More than this and you will obscure the vein. Ensure that the bevel of the needle is upwards to maximise the ultrasound signal of the needle tip.
Insert the needle at a steep angle – about 45 – 60o to the skin otherwise you will never get to the vein. Once the needle is about 5 – 10 mm into the subcutaneous tissues use the ultrasound transducer to find the needle tip. Angle the transducer inwards to facilitate this.
Canulation of the SSV – angle the needle and the transducer towards each other.
Rock the transducer to make sure that you are following the tip of the needle. Advance the needle towards the vein. If you are off-target, withdraw the needle slightly and then advance it in the correct direction. Move the transducer along the leg to track the tip of the needle. Dimple the superficial surface of the vein with the needle tip. Once you see the needle tip enter the lumen of the vein, you may reduce the angle of approach so that the needle runs more parallel with the vein.
Canulation of the SSV – reduce the angle of attack and follow the vein more parallel to the skin.
It is very important to continue to track the tip of the needle and keep it exactly in the centre of the vein as you advance it along the vessel. Once 10 – 20 mm of the canula is in the vein, the canula may be advanced ahead of the needle and needle removed. Secure it to the skin with tape. Check that dark blood returns into the canula and not bright red arterial blood! Inject 2 -3 ml of saline to test the canulation. You should see air bubbles enter the vein but nothing else. If you see an expanding collection of saline around the vein then you have failed!
The same method works well with 'Butterfly' type needles.
I recommend that you insert all the canulas and Butterflies before commencing foam injecting. Once foam has entered the limb is may well prevent a good view of the vein lumen and therefore prohibit further attempts at canulation of more veins.
This technique also works well with direct needle injections using 25 g and 30 g needles when injecting superficial varices. I strongly discourage you from using direct needle injection to treat the main saphenous trunks and perforating veins. The aim of canulation is to minimise the risk of intra-arterial injection. It is common to find large arteries near veins in the femoral triangle, the popliteal fossa and near medial calf perforating veins. If you put foam into one of these you may be lucky to avoid amputating the limb of your patient during follow-up treatment! Superficial varices are usually not accompanied by arteries of any size but inadvertent injection of even a small skin artery may result in substantial skin loss. Ensure that every injection you give enters a structure that appears to be a vein!
Making foam.
At present there is no commercial foam and everyone uses home made foam made from either polidocanol (Sclerovein, Aethoxysclerol) or sodium tetradecyl (Fibrovein, Sotradecol). The most widely used method is the Tessari technique in which 1 part of sclerosant and 3 or 4 parts of air are mixed by passing the components between two syringes connected together.
Tessari method of preparing sclerosant foam.
I recommend that you only prepare 2 ml at a time. This reduces the risks of injecting too much too rapidly and minimises the volume you will need. Pass the sclerosant/air mixture 20 times between the two syringes. The foam is stable for 1 – 2 minutes are preparation.
Treatment – general.
Mark the location of the veins and trunks to be treated with the help of the duplex ultrasound machine. This is best done with the patient standing. Where large varices are present, plan to occlude the proximal saphenous trunks at the first session and treat residual varices after an interval of two (or more) weeks when they will be much smaller.
Lie the patient supine before placing any needle or canula to minimise the risk of syncope!
For the great saphenous vein, place a, 18 g canula in the GSV in the lower third of the thigh. This will treat the vein proximal to this level. In the calf use a 23 g Butterfly to treat the saphenous trunk or any varices. Insert all canulae and Butterflies before any treatment is commenced. The proximal veins rapidly go into spasm once treatment has been commenced.
For the SSV canulate this vein in the mid-calf region using an 18 g canula. Use a 23g Butterfly to treat the distal SSV.
Make the foam using 3% STD (for large saphenous trunks) or 1% STD or 1% polidocanol (for small saphenous trunks or superficial varices). Use 0.2% STD for reticular varices (<3 mm dia) or 0.5% polidocanol. Use a ratio of 0.5 ml of STD to 1.5 – 2 ml of air, except for 0.5% polidocanol where 1 ml solution to 1 ml of air is required for a stable foam.
Treatment – injecting the foam.
Elevate the leg well above the heart to minimise the diameter of the veins – this achieves Fegan's 'empty vein' requirement. .
Inject not more than 2 ml of foam at a time, even into the largest veins. In small veins in the calf consider injection of 1 ml only at a time. Start with the most distally placed injection site and slowly inject foam. Ask the patient to perform a series of ankle dorsiflexions to clear any foam which has reached the deep veins. This MUST be done after every injection! Move the next more proximal injection site and inject some foam. Ask the patient to dorsiflex at the ankle. Treat the LSV in the thigh last of all. It has often become very small in response to previous injections more distally in the limb.
Monitor the extent of spread of the foam using duplex ultrasonography. Look for the development of spasm in treated veins. This usually occurs within 2 mins following successful injection.
Monitor extent of spread of foam and spasm of the vein using ultrasound imaging.
Make further injections of 1 – 2 ml of foam into each needle and canula to reinforce the treatment al ready given. This should be repeated twice. This strategy results in the veins being treated and then re-treated. This has been found by French and Italian phlebologists (and me!) to achieve more effective sclerosis of veins than a single injection. The first injection produces spasm of the treated vein and facilitates the passage of foam to more proximal veins with the second and third injections.
Should this strategy not fill all of the varices make further injections into unfilled varices using a 2 ml syringe and a 25 g or 30 g needle.
The amount of foam required to treat the LSV in the thigh is usually 6 ml, or 8 ml if it is a large vein. On the ultrasound image, look for foam in the vein and spasm of the vein. This gives reassurance of complete treatment. In the calf section of the LSV 2 – 4 ml of 1% STD foam is sufficient. In the SSV 4 – 6 ml of 3% STD foam is required depending on the size of the vein.
Compression.
Effective bandaging is essential!! I use Velband (cotton wool) rolled over the treated veins. This is compressed by either Peha-Haft (Hartmann) or Actico. I hold the bandages in place with Medipore (3M) adhesive tape and put a class 2 compression stocking over all of this. I previously told patients to wear the bandage for 5 days, but have encountered some problems with thrombophlebitis occurring 2 – 8 weeks following treatment. I now recommend that bandages are worn for 10 days. Even longer would be better for very large varices e.g. 14 days. I recommend that the stocking is worn for about 2 weeks. The compression regime should be repeated after each treatment session.
Compression applied by a Pehahaft bandage over a cotton wool (Velband) roll
A stocking is applied over the bandage to compress the foot and ankle
Strategy for treating various common patterns of veins.
Patients with large saphenous varices in the calf filled from the long or short saphenous vein.
In the majority of patients it is useful to treat varices of this type in two sessions, although this is not essential. In the first session treat the proximal saphenous vein, leaving the calf varices until the second session. The calf varices decrease in size greatly within 1 week after this, allowing much easier treatment of the residual calf varices and distal saphenous trunks. For the long saphenous vein, I usually place a canula in the trunk just about the knee, or proximal to any large varicose tributary. Occasionally this necessitates treatment of only the proximal 10 cm of the LSV in the first session, where varices are present in thigh tributaries. For the SSV, the major varices usually emerge from the trunk 10 – 15 cm below the knee. Place the canula just above this level and treat the vein proximal to these varicose tributaries.
Usually foam does not pass distally to the point of canulation of the vein, presumably due to spasm of the vein at the site of puncture. However, to be certain no foam passes distally I compress the saphenous trunk distal to the point of injection.
The first session of treatment often requires only one canulation and series of foam injections via this canula. It can be quickly accomplished. I usually bandage all the varices near the region of injection just in case they are unintentionally occluded by the treatment.
Effect of obliteration of the GSV in the thigh on large calf varices: before and 2 weeks after treatment
In the next session you are left with the distal saphenous trunk(s) in the calf as well as the varices, which are now much smaller. I usually place two or three 23g Butterflies in these veins under ultrasound control. The limb can then be elevated and foam injected (usually 1% STD or 1% polidocanol). In patients with reticular varices and telangiectases I use 0.5% polidocanol. I usually use 1 – 2 ml foam for each Butterfly. Ensure that all varices have been filled with foam. Any which are not filled can be injected directly.
In placing the Butterflies I find that foam spreads in both directions from the point of injection. Therefore, the LSV in the calf can be treated from a Butterfly placed in the mid-calf region. I recommend avoiding injection of the LSV at the ankle with the intention of treating the whole of calf LSV. The foam may simply pass via a medial calf perforating vein risking thrombosis of the posterior tibial veins. In fact, take great care when injecting near the medial calf perforating veins (Cockett perforators). Use small volumes of foam in the region, I suggest not more than 1 ml per injection. The more proximal perforating veins (Boyd's, paratibial) are less of a problem since they are further from the posterior tibial veins.
If you want to occlude the Cockett perforators do not use foam! It is better to use a small volume (0.5 – 1 ml) of 3% STD liquid injected via a Butterfly positioned in the perforator. This should be positioned under ultrasound control and venous blood aspirated and saline injected to confirm that you have the needle in the vein, not the artery. I usually elevate the leg during injection to maximise the efficacy of perforating vein injection.
For the longer perforators (Boyd's, paratibial, lateral popliteal fossa, thigh perforators) it appears to be safe to inject 2 – 4 ml of 3% STD foam directly into the perforator. I have found that this successfully occludes most perforating veins permanently.
Varices in the region of truncal injection.
Occasionally saphenous varices are present in the region of injection of the main saphenous trunk. It is inevitable that foam will enter these varices and it is best to treat them as well at the first session. I recommend that a Butterfly is inserted into one of the varices at the same time that the canula is placed in the saphenous trunk. Elevate the leg and inject the varices first. I use 1% STD or 1% polidocanol foam. Once the varices have been filled, then you can proceed to treat the saphenous trunk with 3% STD foam as usual. This strategy prevents strong sclerosant reaching the small varices where excessive thrombophlebitis might result.
Combined saphenous truncal incompetence and small varices of CEAP C1 type (<3 mm dia).
In patients with reticular varices and telangiectases, these are best managed by foam sclerotherapy of the reticular varices first using 0.5% polidocanol foam. This usually has to be made with a 1:1 ratio of liquid and air to maintain stability. The telangiectases can later be treated with 0.5% polidocanol liquid.
However, in a significant number of patients large varices and small varices are present together. Injection of strong sclerosant into large varices in these patients may result in the appearance of more telangiectases. My patient info sheet warns of this.
I have previously advised simultaneous injection of reticular varices and saphenous varices. However, this may result in excessive thrombus accumulating in reticular varices. I now suggest that in such patients injection should initially be directed towards the saphenous trunks and varices. In later sessions reticular varices may be treated with 0.5% polidocanol foam.
Reticular varices do not appear to depend for their existence on saphenous truncal incompetence. These veins don't diminish in size after treatment of the saphenous trunk. There is no advantage to deferring injection of this type of vein to a subsequent session after the trunk has been occluded. More rapid progress is made if at least some of the reticular varices are treated in the same session as the associated incompetent saphenous trunk.
Problems
The most frequent problem is thrombophlebitis. This can be managed with compression and analgesia. Affected veins can be drained using a large needle (14G) under ultrasound control and some local anaesthesia. I usually employ the needle from a 14g Venflon which is long enough to reach along the lumen of an occluded vein as well as being large enough to allow aspiration of thrombus.
If a vein or varix contains a large amount of thrombus, this can be aspirated via a large (14G) needle within 1 – 2 weeks of treatment and has the advantage that the palpable lump is rapidly removed. On ultrasound imaging the thrombus is usually slightly compressible at this stage and relatively echolucent.
After this the thrombus becomes more solid and incompressible with increased echogenicity on ultrasound imaging. It is impossible to aspirate this. After 4 – 8 weeks, echolucency returns to some veins. These appear to be the ones that cause the thrombophlebitis. The thrombus can usually be retrieved with the large needle at this stage with removal of lumps and any associated discomfort. I find that this is necessary in only a small proportion of patients.
Take care not to inject STD foam outside a vein – this sclerosant causes ulcers which are very slow to heal when injected as a liquid outside a vein. Check the position and function of any canula or needle through which you intend to inject STD foam or liquid. Use ultrasound imaging to make sure that a test dose of saline goes into the vein and not around the vein! I have seen extravasation of STD foam in one or two patients. It usually results in an inflammatory lump at the injection site. This resolves completely over 2 – 4 weeks. I have not caused an injection ulcer with STD foam – as yet!
Polidocanol is much safer in this respect. It causes no significant problem if injected at low concentrations and amounts outside the vein. In fact, the datasheet for this drug suggests extravascular injection can be used to treat telangiectases! However, I don't think this works very well.
Extravascular injection of sclerosant foam usually causes pain. I always check with the patient that my injection is causing no discomfort as a further measure to avoid extravascular injection.
DVT has been seen occasionally after this treatment, most frequently affecting the calf veins. This should be managed conventionally.
Veins recanalise in a few patients. This usually occurs within 6 months, so a review visit a 6 months may detect this and allow pre-emptive re-treatment to be given.
Systemic complications
The most frequent problem which I deal with is visual disturbance. This occurs following both liquid and foam sclerotherapy but is more frequent after foam treatments. It occurs in patients who have a previous history of migraine most frequently but may occur in anyone. A scotoma develops associated with other visual phenomena such as a ground glass appearance in part of the visual field and irregular coloured patterns. This resolves within 30 mins in most patients. It is highly likely to return in subsequent sessions of treatment and I recommend that affected patients lie supine for up to 30 minutes following injection of foam to prevent this problem.
Some patients may develop tightness in the chest or coughing afterwards. I believe that this is a direct effect of the foam and can also occur following injections of liquid sclerosant. This also resolves in about 30 minutes. Again lying supine for some time after treatment may be useful.
Allergic reactions may follow injection of either of the sclerosants mentioned here. Appropriate drugs should be available to manage this problem.
More difficult cases
Patients with recurrent varicose veins following surgery are much easier to manage using foam sclerotherapy than by further surgery. However, they often have few straight veins and canulation may be more difficult than with primary varicose veins. Where this is the case you should gain considerable practice in placing needles in straight veins before attempting this more difficult group of patients.
Patients with recurrence at the SFJ and SPJ can be readily managed by foam sclerotherapy. You need to place a canula or Butterfly fairly close to the junction and inject 4 – 6 ml of 3% STD foam. Residual varices and segments of saphenous trunk may require the placing of more needles prior to the start of injection in order to ensure that all varices are filled with foam during the treatment. Recanalisation of SFJ and SPJ recurrences managed by foam sclerotherapy is no more frequent than following treatment of primary incompetent junctions. This is therefore a very useful strategy in patients who have had many previous operations for varicose veins.
Conclusions
Foam sclerotherapy is a very useful technique but carries significant and grave risks if not used carefully. The guidance above is a distillation of my experience of treating near 1000 patients. However, I can't teach you foam sclerotherapy by writing about it. Try to gain experience under the guidance of a skilled practitioner of this art before you start our on your own.
Philip Coleridge Smith DM FRCS
Consultant Vascular Surgeon and Reader in Surgery
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