Sclerotherapy of Varicose Veins and Telangiectasias: A 2-Year Experience with Sodium Tetradecyl Sulphate

Paul Kenneth Thibault MBBS

Central Vein and Cosmetic Medical Centre
Suite 1, 41 Belford Street
Broadmeadow
NSW 2292
Australia

Telephone +61 2 49610688
Telefax +61 2 49610687

Address correspondence and reprint requests to : Dr Paul Thibault, Suite 1, 41 Belford Street, Broadmeadow, NSW 2292 Australia.

Abstract
BACKGROUND. Sodium tetradecyl sulphate is a sclerosing solution that has been widely used for the treatment of varicose veins and telangiectasias over the past 40 years. Despite the high efficacy and an excellent safety profile of sodium tetradecyl sulphate, recent reports have indicated that many phlebologists believe that Polidocanol is more effective and has less adverse effects.
OBJECTIVE. To evaluate the incidence of adverse effects found with sodium tetradecyl sulphate and compare with those reported for Polidocanol.
METHODS. A 2-year prospective study of sodium tetradecyl sulphate usage and adverse effects is reported. The treatment details and adverse effects of 2665 patients were studied.
RESULTS. Apart from the occurrence of 4 anaphylactoid reactions, the incidence of adverse effects were similar to those reported for polidocanol.
CONCLUSION. Sodium tetradecyl sulphate is an effective sclerosant with a high safety profile.

Sclerotherapy of Varicose Veins and Telangiectasias: A 2-Year Experience with Sodium Tetradecyl Sulphate

In recent years sclerotherapy has been used extensively in the treatment of varicose veins and telangiectasias. In Australia there are only 3 commonly used sclerosing solutions, sodium tetradecyl sulphate (STS), polidocanol (POL) and hypertonic saline (HS). Of these, only STS is registered for use as a sclerosant. Polidocanol is currently undergoing clinical trials under the Clinical Trials Notification Scheme1.
Detergent solutions, such as STS and POL act specifically on venous endothelium producing maceration of the endothelium within 1 second of exposure2. The hydrophilic and hydrophobic poles of the detergent orientate themselves so that the hydrophilic pole is within the water in the bloodstream and the hydrophobic pole attaches to the lipid component of the endothelial cell membrane. The effect of detergent solutions is concentration dependent. However the concentration required is dependent on a number of factors including vessel diameter, rate of blood flow and anatomical region. This feature of concentration dependency allows the use of detergent solutions in the treatment of the largest varicose veins to the smallest telangiectasias.
STS was first described in 1946,3 and Fegan4 popularized it for the treatment of varicose veins. However STS caused an unacceptable incidence of cutaneous ulceration and pigmentation when the commercially produced 1% solution was used for the injection of small veins.5 Over the past 10 years, with the correct dilution of STS ranging from 0.1% to 0.5%, this sclerosant has been widely used for treating smaller reticular varicose veins and telangiectasias.6
In 1995 the results of the Australian Polidocanol study were published.1 This study on the reported results of 98 physicians treating 16,804 limbs compared POL very favourably with both STS and HS. Eighty five percent of physicians who had previously used STS rated efficacy and complications of POL significantly better than STS. However, this study was not a true comparative study in that patients were not randomised and only the results and complications of POL were reported. In addition, as explained above, most physicians who used STS in the treatment of smaller varicose veins, reticular veins and telangiectasias prior to 1990 used far too high concentrations resulting in relatively high incidence of adverse effects.5 It is generally regarded that the action of POL is weaker than STS1,7 and higher concentrations appear necessary to produce the same effect. Conversely, when treating smaller veins the concentration of STS needs to be reduced compared with POL in order to compare "apples with apples". In my experience this ratio is approximately 1 to 3. For example, a 2-3 mm reticular vein will require POL 1% whereas the correct STS concentration will be 0.3% (Table 1).
The aim of the present study was to report my clinical experience with STS over a 2-year period and compare the incidence of adverse effects with those reported in the Australian Polidocanol Trial.

METHODS
All newly presenting patients treated with STS in the clinic between July 1996 and June 1998 were entered into the study. There were no age or sex exclusions and patients with varicose veins and telangiectasias of the lower limbs or facial telangiectasias were included.
The concentrations of STS used were 3% for incompetent axial veins and perforators, 0.75% for large branch varicose veins 3-5mm in diameter, 0.5% for branch varicose veins 2-3mm in diameter, 0.3% for reticular veins 1-2mm in diameter, 0.12% for lower limb telangiectasias and 0.1% for facial telangiectasias. The appropriate concentrations were achieved by diluting the standard 3% solution with normal saline. Isotonic normal saline was used in preference to hypotonic sterile water to minimise pain on injection. Treatments were generally spaced fortnightly with a routine follow-up examination 4 weeks following the final treatment. Intravascular haematomata were evacuated as necessary at each attendance.
Immediately after sclerotherapy for leg veins, a Class II thigh high compression stocking was applied, and worn continuously for 7 days and then during waking hours for another 7 days. Following sclerotherapy to leg veins, all patients were instructed to walk at a moderate pace for 20 minutes immediately after treatment and for 1 hour daily.
All clinical data regarding treatment details (solution strengths and volumes) and adverse effects and complications were entered into the Phlebology and Cosmetic Medicine Computer System (Central Vein and Cosmetic Medical Centre, Broadmeadow, Australia). (Figures 1 and 2). The data was read into SAS (SAS Institute Inc, Cary, NC) for analysis and presented for comparison with data reported from the Australian Polidocanol Trial.

RESULTS
The treatment details and adverse effects of 2665 patients were studied. Ages ranged from 5 to 84 with a mean age of 46.65 (Table 2). Details of STS concentrations and volumes for each treatment session are shown in Table 3. The highest dose given was 11 ml of 3% and the lowest 0.05ml of 0.1%. The largest volumes used however were with the 0.5%, 0.3% and 0.12% strengths. The local adverse effects that occurred in the 2- year period are presented in Table 4. Major complications and systemic reactions are presented in Table 5. The adverse effects and complications that were reported in the Australian Polidocanol Trial are also presented in Tables 4 and 5 for comparison.

DISCUSSION
STS is a versatile sclerosant that can be effectively used for the treatment of a wide range of varicose veins and telangiectasias. The essential concept in using STS successfully is to use the appropriate concentration for the given vein diameter. This will result in minimisation of adverse effects. Although STS has a predictable and constant effect within the same caliber and type of vein at the same level or area of the leg, there can be variation in sensitivity among patients. For example, when treating reticular veins and telangiectasias I have observed that cigarette smokers appear more sensitive to solution concentration, possibly as a result of chronic endothelial damage and increased endothelial permeability caused by carbon monoxide and nicotine.10 The main disadvantage of STS is the pain it causes for several minutes after injection, particularly when reticular and small varicose veins are being treated. However this disadvantage is outweighed by the relatively large total volumes that can be safely injected in a treatment session, especially with the diluted solutions. In contrast, the total dose of POL needs to be carefully limited in order to avoid negative inotropic local anaesthetic effects.
The incidences of local adverse effects in this study were similar to those reported in the Australian Polidocanol Study. The incidence of cutaneous ulceration, postsclerotherapy pigmentation and superficial thrombophlebitis were virtually identical. These adverse effects are recognised as being concentration dependant.5,9 This would support the author's view that many of the physicians taking part in the Australian Polidocanol Study had used STS in too strong concentrations in the past. The incidence of telangiectatic matting appears to be greater in this STS study although numbers are too small to have statistical significance. This adverse effect is not generally regarded as being concentration dependent9 and Tretbar5 has noted the absence of telangiectatic matting around scars that resulted from the use of excessive STS concentration that caused cutaneous ulceration. In my experience, many instances of telangiectatic matting arise when there has been inadequate treatment of proximal sources of reflux (including reticular veins) and therefore may be seen when an insufficient concentration of sclerosant has been used.
Of the systemic reactions, anaphylactoid reactions and deep venous thrombosis warrant further discussion. There were no deep vein thromboses in the STS study, whilst there were 3 reported from the Polidocanol study. Two of those thromboses were relatively mild calf vein thromboses. Again numbers are too small to be able to make any valid conclusion when comparing the two sclerosants. The important factors contributing to postsclerotherapy deep venous thrombosis are volume of injection at each site, inappropriate compression and hypercoagulable states including oral contraceptive agents and oestrogen replacement therapy,9 rather than the type of sclerosant used.
In the present study there were 4 cases of non-fatal anaphylactoid reactions. In comparison there were no reports of anaphylactoid reactions in the Australian Polidocanol Study. This is consistent with the incidence of anaphylactoid reactions reported in the literature.9 All 4 cases occurred following injection of the 3% solution. Typically, the reaction occurs from 10 -30 minutes from commencement of the injections and is manifested by facial flushing, generalised urticaria followed by the patient feeling unwell (a feeling often described as impending disaster), dizziness (hypotension) compensatory tachycardia, shortness of breath and wheeze and finally gastrointestinal symptoms of nausea, vomiting and abdominal pain. All 4 patients responded well to immediate injection of epinephrine 0.5mL of 1:1000 aqueous solution subcutaneously or intramuscularly, followed by promethazine HCl 25mg or 50mg intramuscularly. Hospitalization was not required for any of the patients. Therefore it is advisable that any physician using STS should be well aware of the early signs of anaphylactoid reaction and have the appropriate emergency equipment immediately at hand, as prompt treatment prevents the patient's condition becoming critical.
Finally, there is no known ideal sclerosant. Both STS and POL are very good agents and every sclerotherapist should become completely familiar with one or both. Each has its advantages and disadvantages and thorough knowledge of the properties of each sclerosant, when applied with the fundamentals of good sclerotherapy practice will ensure optimum results.

References

1. Conrad P, Malouf GM, Stacey MC. The Australian Polidocanol Study: Results at 2 years. Dermatol Surg 1995; 21:334-336.

2. Goldman MP, et al. Sclerosing agents in the treatment of telangiectasias. Arch Dermatol 1987:123:1196-1201.

3. Reiner L The activity of anionic surface active compounds in producing vascular obliteration. Proc Soc Exp Bio Med 1946;62:49-54.

4. Fegan WG. Continuous compression technique of injecting varicose veins. Lancet 1963;2:109-12.

5. Tretbar LL. Injection sclerotherapy for spider telangiectasias: A 20-year experience with sodium tetradecyl sulphate. J Dermatol Surg Oncol 1989;15:223-5.

6. Thibault PK. Treatment of telangiectasias. In "Varicose Veins and Telangiectasias: Diagnosis and Treatment." Bergan JJ, Goldman MP (Eds), Quality Medical Publishing Co., St Louis, 1993;373-88.

7. Imhof E, Stemmer R. Classification and mechanism of action of sclerosing agents. Soc Fran Phleb 1969; 22:143-148.

8. Neumann HAM. Commentary. The Australian Polidocanol Study: Results at 2 years. Dermatol Surg 1995;21:337-336.

9. Goldman MP. Complications and adverse sequelae of sclerotherapy. In: Goldman MP, editor: Sclerotherapy: Treatment of varicose and telangiectatic leg veins, St Louis,1995, Mosby-Year Book.

10. Kjeldson K, Astrup P, Wanstrup J. Ultrastructural intimal changes in the rabbit aorta after a moderate carbon monoxide exposure. Atherosclerosis 16:67-82, 1972.

SEE TABLES BELOW

TABLES

TABLE 1

Vein Calibre STS Concentration Polidocanol Concentration

mm % %

0.1 - 0.5 0.1 0.25

0.5 - 1.0 0.15 0.5

1.0 - 2.0 0.3 1.0

2.0 - 3.0 0.5 1.5

3.0 - 5.0 0.75 2.0

5.0 - 8.0 1.0 - 3.0 3.0 - 5.0

TABLE 2

	Age at Sclerosant Use
	(n=2665)
Mean	46.65
SD	12.98
Median	46.06
Minimum age	5
Maximum age	84

TABLE 3

	Total dose (mgs)	3% (mls)	0.75% (mls)	0.5% (mls)	0.3% (mls)	0.12% (mls)	0.1% (mls)
N = 2686		714	672	1690	1556	1105	258
Mean	8.42	4.52	4.23	8.01	7.3	3.69	1.35
ST Dev	6.26	2.24	3.15	5.41	6.26	3.91	1.86
Median	7.44	4	4	7	6	2	0.5
Range	0.005- 33	0.25 -11	0.5 - 24	0.5 - 36	0.2 - 46	0.1 -40	0.05 - 12

TABLE 4

Complication	STS N=2,686	POL N=16,804
Ulceration	4 (0.15%)	32 (0.2%)
Significant or severe pigmentation	5 (0.2%)	30 (0.2%)
Telangiectatic matting Superficial thrombophlebitis	4 (0.15%) 3 (0.1%)	7 (0.04%) 14 (0.08%)