The care of patients with varicose veins and associated chronic ...

JOURNAL OF VASCULAR SURGERY
Volume 53, Number 16S Gloviczki et al 33S
Table VIII. Indications and concentrations of sclerosing
agents
Indications STS Polidocanol
Varicose veins 8 mm 0.5%-3.0% 1%-3% a
Reticular veins 2-4 mm 0.25%-0.5% 0.6%-1.0%
Telangiectasias 0.1-2.0 mm 0.125%-0.25% 0.25%-0.6%
STS, Sodium tetradecyl sulfate.
a Not approved for varicose veins in the United States.
Alcohol agents. Alcohol agents are weak sclerosants
that cause irreversible endothelial damage by contact. Glycerin
is a corrosive agent that destroys the cell surface
proteins by affecting chemical bonds. Chromated glycerin
is used most frequently as a solution of glycerin, sterile
water, and benzyl alcohol (Chromex, Omega Laboratory).
It is not approved in the United States. It is usually mixed
with 1% lidocaine and epinephrine. Chromated glycerin is
safe and rarely leads to tissue necrosis, hyperpigmentation,
or allergy. Suitable for treatment of small veins or telangiectasia,
it may cause hematuria when used in a higher
concentration.
Liquid sclerotherapy. The sclerosing chemicals need
to be diluted before use, and the concentration of the
solution should be the lowest when used for treatment of
very small diameter veins, such as telangiectasia. Recommended
concentrations of STS and polidocanol are listed in
Table VIII.
Liquid sclerotherapy is performed using small tuberculin
syringes and a 30- or 32-gauge needle. Treatment is
usually started with larger varicose veins and ends with
reticular veins and telangiectasia. The proximal part of the
limb is treated first and the distal part second. Using loupes
for magnification and transillumination (Veinlite, Trans-
Lite, Sugar Land, Tex; VeinViewer, Luminetx, Memphis,
Tenn) helps intraluminal injection and avoids extravasation
of the drug. The injection maximum of 1.0 mL of the
chemical to one site is recommended, with not more than
10 to 20 injections performed per session. Severe pain
during injection may signal extravasation, and further injection
should be avoided. 29 Gauze pads are placed on the
injection sites, and the patient is instructed to wear 30 to 40
mm Hg graduated compression stockings for 1 to 3 days
after treatment of telangiectasia and reticular veins and at
least 1 week after treatment of varicose and perforating
veins.
Foam sclerotherapy. Foam sclerotherapy of the saphenous
vein is the least invasive of the endovenous ablation
techniques. The European Consensus Meetings on
Foam Sclerotherapy 308,309 reported that foam was an effective,
safe, and minimally invasive endovenous treatment
for varicose veins with a low rate of complications.
The most popular technique used today was developed
by Tessari et al 312 using a three-way stopcock connected
with two syringes. Experts recommend a ratio of 1 part
solution of STS or polidocanol to 4 or 5 parts of air. 313
Mixing the drug with air using the two syringes and push-
ing the mixture from one syringe into the other 20 times
results in an approximate bubble size of 100 m.
Coleridge-Smith 306 advises to cannulate the veins in
supine patients and then elevate the limb 30° to inject the
foam. Ultrasonography is used to monitor the movement
of foam in the veins. The saphenous trunk is injected first,
followed by varicose and perforating veins if indicated. A
maximum of 20 mL of foam is injected during one session.
Bergan 313 recommends elevation of the limb for 10 to 15
minutes after injection to minimize the volume of foam
that gets into the systemic circulation. The procedure is
completed by placing a short stretch bandage or 30 to 40
mm Hg graduated compression stockings (or both) on
the limb. Although most authors recommend 1 to 2
weeks of compression, 313,314 a recent RCT found no
advantage to compression bandaging for 24 hours
when thromboembolus-deterrent stockings were worn
for the remainder of 14 days. 315
Complications. Severe complications after sclerotherapy,
such as death, anaphylactic reaction, pulmonary emboli,
stroke, and large areas of skin necrosis, are very rare
(0.01%). 316 Severe but rare complications also include
thrombophlebitis, nerve damage (saphenous, sural), DVT,
or inadvertent arterial injection of the solution. 317,318
Transient neurologic adverse effects such as visual disturbance,
migraine-like headache, or confusional state may
occur and are more frequent in patients with a patent
foramen ovale. 319
Most complications are minor, and include matting,
pigmentation, pain, allergy, and skin urticaria. The higher
the concentration of the agent, the higher the likelihood of
hyperpigmentation, a minor complication that can be observed
in up to 30% of the cases. 320 Between 70% and 95%
of the pigmentations, however, resolve by 1 year after
therapy. 317
The incidence of major neurologic events after foam
injection is rare; instances of stroke were reported by Bush
et al 321 and others. 319,322,323 Immediate treatment with
100% oxygen and possibly hyperbaric oxygen therapy
should be considered. Factors implicated in the risk of stroke
after foam sclerotherapy include the use of air instead of
carbon dioxide to prepare the foam, large bubble size, a patent
foramen ovale, failure to elevate the limb after treatment,
prolonged immobility after therapy, and an excessive amount
of foam used during one session. 319,322-324 Standardization
of the bubble size using commercially prepared microfoam
and the replacement of air with carbon dioxide in
the solution may decrease the risk of neurologic
complications. 325
A recent study Regan et al 326 proposed that the composition
and properties of the foam, including bubble size
and gaseous components, may indeed contribute to the
potential for microcirculatory obstruction and cerebral
ischemia. The authors tested an ultralow nitrogen polidocanol
endovenous microfoam with controlled bubble size
and density and found that patients treated with foamed
liquid sclerosants are commonly exposed to cerebrovascular
gas bubbles. In a series of 60 high-risk patients with