Inclusion Criteria:

• Males and females aged 18 to 60 with severe varicose veins, CEAP classes 3, 4 and 5 (CEAP is a classification and grading system for chronic venous disease)
• Saphenofemoral junction (SFJ) incompetence. Retrograde blood flow in the GSV, greater than or equal to 1.0 second demonstrated by duplex scanning.
• Normal MRI, as assessed on MRI examination performed within 5 days prior to procedure.
• Patient must be willing and able to participate in the study and provide written informed consent.

Exclusion Criteria:

• Presence of venous ulcers (i.e. CEAP classification C6) or local infection in the limb to be treated.
• Incompetence of the small saphenous vein (SSV) in the leg to be treated. Venographic or ultrasonographic evidence of current or previous deep vein thrombosis (DVT) (see Appendix IV).
• Deep venous occlusion and/or incompetence. Evidence of deep venous reflux is acceptable if it is confined to a limited segment caused by filling of the incompetent superficial system through a perforator or the SFJ.
• Patients with known atherosclerotic disease or presence of major risk factors, including LDL cholesterol greater than 130 mg/dl, blood pressure greater than 140 mmHg systolic or 90 mmHg diastolic, or diabetes requiring treatment with oral hypoglycemic drugs or insulin.
• Smokers.
• History suggestive of cerebral atherosclerosis, transient ischemic attack (TIA), stroke, presence of carotid bruit or history of abnormal carotid duplex examination.
• Clinically significant dilated cardiomyopathy, evidence of regional wall motion abnormalities suggestive of prior myocardial infarction, rheumatic mitral valve disease, moderately severe or worsening cardiac valvular disease (> 2+ on a scale of 4), known or suspected congenital heart disease, evidence of right sided volume or pressure overload, history of atrial fibrillation. Patients with PFO, atrial septal defect, or other right-to-left shunt are not excluded unless associated with other abnormalities as above.
• Peripheral vascular disease.
• Spontaneous emboli seen on TCD prior to contrast injection.
• Body Mass Index >30.0.
• Recent or current upper respiratory tract illness or other cause of increased coughing.
• Arterial insufficiency in the leg to be treated (ankle: brachial pressure ratio less than 0.9).
• Reduced mobility - unable to maintain a brisk walk unaided for a minimum of 5 minutes per hour per day.
• Prolonged automobile or air travel (>4 hours) 1 month prior to treatment, or planned within 1 month of proposed treatment.
• Current or prior pulmonary embolism.
• Major surgery, prolonged hospitalization or pregnancy within 3 months of screening.
• Hormone replacement therapy or hormonal contraception (oral or dermal patch).
• Current or recent (<7 days before treatment) aldehyde dehydrogenase inhibitor therapy, e.g. disulfiram, or other drugs with similar reactions to alcohol (metronidazole, tinidazole).
• Current anticoagulation therapy.
• Inability to identify a unilateral or bilateral temporal bone window and middle cerebral artery signal by transcranial Doppler ultrasound.
• Inability to undergo magnetic resonance imaging of the brain
• Participation in a clinical study involving an unlicensed pharmaceutical product within the 3 months of screening.
• Previous enrollment in this study.
• Major co-existing disease (e.g. malignancy, pulmonary disease, renal or hepatic insufficiency).
• Known allergic response to polidocanol or severe and multiple allergic reactions.
• Women of childbearing potential not using effective contraception
• Pregnant or lactating women.
• Current alcohol or drug abuse.
• Clinically significant laboratory abnormalities in the opinion of the investigator.