Please select the eligibility criteria that correspond to the clinical trial below.
Title: Comparative Randomized Clinical Trial of Steam Ablation Versus Endovenous Laser Ablation for the Treatment of Great Saphenous Veins
Brief Summary: Endovenous laser ablation is a common therapy of great saphenous vein insufficiency with a very high success rate. It works by heating and thereby obliterating the vein. Steam ablation is a new therapy that also works by heating and thereby obliterating the vein. The hypothesis of this study is that steam ablation is as effective as laser ablation, but that it results in better secondary outcomes (e.g., lower pain scores).


Options:
A: Inclusion Criteria:

* Patients over 18 years old
* Insufficiency of the GSV measured with ultrasound imaging, reflux \> 0.5 s, and diameter of vein \> 0.5 cm
* Symptoms of chronic venous insufficiency
* No prior treatment of the insufficient GSV
* Informed consent

Exclusion Criteria:

* Acute deep or superficial vein thrombosis
* Agenesis of deep vein system
* Vascular malformation or syndrome
* Post-thrombotic syndrome, occlusive type
* Pregnancy
* Immobility
* Allergy to lidocaine
* Arterial insufficiency
B: Inclusion Criteria:

* Aged 18 or over
* Symptomatic SVI which will likely benefit from treatment in the opinion of an experienced specialist and the participant
* Clinical grades C2-C6 on the CEAP system
* Superficial axial incompetence with proposed treatment lengths of at least 10cm
* Treatment with either endovenous laser ablation or mechanochemical ablation is technically feasible in the view of an experienced endovenous specialist
* Patient is willing to participate (including acceptance of randomisation to either treatment) and give valid, informed consent in the English language

Exclusion Criteria:

* One of the treatments is thought to be preferable by either the patient or an experienced endovenous specialist
* Unwilling or inability to comply with the requirements for follow-up visits
* Known allergy to medications or dressings used in the treatment
* Known right to left circulatory shunt
* Evidence of acute deep venous thrombosis or complete ipsilateral occlusion
* Pelvic vein insufficiency
* Active or recent thrombophlebitis (within 6 weeks)
* Impalpable foot pulses with an Ankle-Brachial Pressure Index of less than 0.8
* Pregnancy or breast feeding
* Active malignancy
* Immobility
* Involvement in other CTIMP trials within the last 6 months
C: Inclusion Criteria:

* Primary, symptomatic, varicose veins.
* Isolated Saphenofemoral junction (SFJ) incompetence leading to long saphenous (LSV) reflux on duplex ultrasound.
* LSV of 4mm diameter at the knee.
* Ability to give informed written consent.

Exclusion Criteria:

* Inability to give informed written consent.
* Symptomatic or complicated varicose veins not attributable to SFJ/LSV reflux.
* Evidence of deep venous reflux on duplex scan.
D: Inclusion Criteria:

* Age between 18 and 60 years
* Clinical, etiologic, anatomic, pathophysiologic (CEAP): clinical grades 2 to 5 (C2-5), primary (Ep), superficial (As) and reflux only (Pr)
* Duplex scan confirmed primary bilateral GSV insufficiency requiring surgery (insufficiency with reverse venous flow was regarded significant if persisting more than 0.5 seconds in a standing position)
* Duplex scan confirmed suitability for RFA (see exclusion criteria)
* Patients able to give informed consent

Exclusion Criteria:

* Varicose veins without GSV insufficiency on duplex scan
* Previous varicose vein surgery
* Associated small saphenous vein reflux, duplication of the GSV at the SFJ, deep venous insufficiency or previous DVT on duplex scan
* GSV diameter \<3 mm or \>12 mm in the supine position
* Thrombus in the GSV
* Patients with a pacemaker or internal defibrillator
* Concomitant peripheral arterial disease (ankle-brachial pressure index of \<0.9)
* Patients on oral anticoagulants
* Patients with high blood pressure not controlled by medication
* Patients with known thrombophilia, cancer or lupus
* Pregnancy

Answer: A