The most commonly used agents are hypertonic saline, sodium tetradecyl sulfate, polidocanol, and chromated glycerin.
Hypertonic saline 23.4% concentration is approved by the US Food and Drug Administration (FDA), but its use in sclerotherapy is off label.
The principal advantage of this agent is the fact that it is a naturally occurring bodily material with no molecular toxicity.
It is not widely accepted as a sclerosing agent because it can cause pain, burning, and leg cramps upon injections; if extravasated, it likely causes significant tissue necrosis; it is highly likely to produce marked postsclerotherapy hemosiderin staining, which is cosmetically unacceptable; and it is difficult to achieve adequate sclerosis of large vessels without exceeding a tolerable salt load.
Suggested hypertonic saline concentrations are 23.4% for reticular veins (2-4 mm) and venulectasias (1-2 mm) and 11.7% (half strength) for telangiectasias (< 1 mm).
Sodium tetradecyl sulfate, a synthetic surfactant (soap), is the only FDA-approved sclerosant in the United States.
It is commercially available in 1% or 3% standard concentrations. This sclerosant is reliable, safe, and effective.
The main clinical concerns stem out of its tendency to cause postsclerotherapy hyperpigmentation in up to 30% of patients, a high likelihood of tissue necrosis upon extravasation (especially when injected in high concentrations), and occasional cases of anaphylaxis.
Suggested sclerosant concentrations are 0.25-0.4% for reticular veins (2-4 mm) and venulectasias (1-2 mm) and 0.1-0.2% for telangiectasias (< 1 mm).
Polidocanol is a nonester local anesthetic, popular in Europe, that was approved in March, 2010 by the FDA for use in the United States.
It is painless upon injection, does not produce tissue necrosis if extravasated, and has a very low incidence of allergic reactions, although few cases of anaphylaxis have been reported.
Also, in some patients, it may produce hyperpigmentation.
The maximum daily dosage is 2 mg/kg. Suggested sclerosant concentrations are 0.5-1.0% for reticular veins (2-4 mm) and venulectasias (1-2 mm) and 0.25-0.75% for telangiectasias (< 1 mm).
Although 72% chromated glycerin (Sclermo) is very popular in Europe, it has not yet been FDA-approved for use in the United States.
Only recently has interest in its use come to pass in the United States.
Compared to other sclerosants, it is very weak and is essentially useful for treatment of small vessels.
The main advantages of glycerin are that it rarely causes posttreatment hyperpigmentation, telangiectatic matting, or tissue necrosis if extravasated.
On the other hand, it is very viscous, causes pain upon injection (for that reason, it is often compounded with lidocaine to decrease pain), is highly allergenic, and could lead to ureteral colic and hematuria.
For spider veins and reticular veins, glycerin seems to be more effective than polidocanol, with fewer adverse effects but more pain.