Condition category
Circulatory System
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
Up to 15% of men and 25% of women at some point in their life develop swollen and enlarged veins called varicose veins. This results in about 95,000 operations being performed each year in the NHS in England alone. There is considerable variation across the UK in accessing treatment for varicose veins, and also to the type of treatment offered. The most common treatment offered is surgery, which involves stripping out the veins under general anaesthetic. Recently, new treatments have been developed for treating varicose veins. These are called minimally invasive techniques as they can be given under local anaesthetic and so avoid the scars and bruising associated with surgery. They may also allow a quicker return to normal daily activities and work, more rapid treatment for a greater number of people, and result in fewer complications. They also allow expensive operating theatre time to be freed up. The two most common types of minimally invasive treatment are foam sclerotherapy and endovenous laser ablation. Foam sclerotherapy involves injecting special foam into your veins that scars the veins and seals them closed. Endovenous laser treatment involves having a tiny laser inserted into your vein which delivers energy that heats up the vein and seals it closed. Both techniques have been classified as safe to use in the NHS, although we have been advised to carefully monitor any side effects that might occur following foam sclerotherpy. Despite good short-term results, success in the long term is unclear. This study will assess this and determine the need for a second course of treatment.

Who can participate?
Patients aged over 18 with varicose veins

What does the study involve?
Participants are randomly allocated to be treated with either surgery, foam sclerotherapy or both endovenous laser ablation and foam sclerotherapy. Participants are followed-up for six months initially (and then for up to 5 years) and are asked about their varicose veins, their general health and any visits to their GP or hospital about their varicose veins.

What are the possible benefits and risks of participating?
Not provided at time of registration

Where is the study run from?
Aberdeen Royal Infirmary (UK)

When is the study starting and how long is it expected to run for?
June 2008 to May 2011

Who is funding the study?
Health Technology Assessment Programme (UK)

Who is the main contact?
Dr Julie Brittenden

Trial website

Contact information



Primary contact

Dr Julie Brittenden


Contact details

c/o Vascular Department
Ward 36
Aberdeen Royal Infirmary
AB25 2ZN
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

HTA 06/45/02

Study information

Scientific title

Randomised controlled trial comparing foam sclerotherapy, alone or in combination with endovenous laser therapy, with conventional surgery as a treatment for varicose veins


Study hypothesis

Foam sclerotherapy is more cost-effective in terms of incremental cost per quality-adjusted life year compared to surgery or laser therapy.

More details can be found at:
Protocol can be found at:

Ethics approval

Not provided at time of registration -– submission pending as of 25/02/2008

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Patient information can be found at:


Varicose veins


Arm 1: Foam sclerotherapy
Arm 2: Foam sclerotherapy + endovenous laser therapy
Arm 3: Conventional surgery

Intervention type



Drug names

Primary outcome measure

The following will be assessed at 6 months:
Primary patient outcome:
1. Disease specific: Aberdeen Varicose Vein Questionnaire
2. Generic: EuroQol (EQ-5D), the 36-item Short Form health survey (SF-36)

Primary economic outcome:
3. Incremental cost per quality adjusted life year (QALY)

Secondary outcome measures

1. Costs to the health service and patients and any subsequent care
2. Technical success of venous intervention at 6 weeks and 6 months
3. Clinical success of venous intervention at 6 weeks and 6 months
4. Disease-specific and generic quality of life at 6 weeks
5. Behavioural recovery

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Adult patients (aged over 18 years old)
2. Those who are referred to the surgical out-patient department for treatment of primary varicose veins with symptomatic (CEAP [Clinical, Etiological, Anatomical, Pathological elements] classification grade 2 or above) primary long or short saphenous main stem incompetence (reflux >1 second on duplex scanning)
3. Suitable for day case treatment

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Current deep vein thrombosis
2. Deep venous incompetence
3. Acute superficial vein thrombosis
4. Allergy to sclerosant
5. Pregnancy or breastfeeding
6. History of hypercoagulability
7. Arterial disease (ankle brachial pressure index <0.8)
8. Inability to mobilise post-procedure
9. Needle phobia
10. Long or short saphenous vein less than 3 mm in diameter or greater than 15 mm and tortuous veins that are considered to be unsuitable for endovenous laser ablation (EVLA) due to difficulties in passing the guide wire
11. Inability to complete study questionnaires

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Aberdeen Royal Infirmary
AB25 2ZN
United Kingdom

Sponsor information


University of Aberdeen (UK)

Sponsor details

c/o Dr E Rattray
Research & Innovation
University Office
Kings College
AB24 3FX
United Kingdom

Sponsor type




Funder type


Funder name

Health Technology Assessment Programme

Alternative name(s)

NIHR Health Technology Assessment Programme, HTA

Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2014 results in:
2. 2014 results in:
3. 2015 results in:
4. 2019 5-year results in:

Publication citations

  1. Results

    Brittenden J, Cotton SC, Elders A, Ramsay CR, Norrie J, Burr J, Campbell B, Bachoo P, Chetter I, Gough M, Earnshaw J, Lees T, Scott J, Baker SA, Francis J, Tassie E, Scotland G, Wileman S, Campbell MK, A randomized trial comparing treatments for varicose veins., N. Engl. J. Med., 2014, 371, 13, 1218-1227, doi: 10.1056/NEJMoa1400781.

  2. Results

    Tassie E, Scotland G, Brittenden J, Cotton SC, Elders A, Campbell MK, Campbell B, Gough M, Burr JM, Ramsay CR; CLASS study team, Cost-effectiveness of ultrasound-guided foam sclerotherapy, endovenous laser ablation or surgery as treatment for primary varicose veins from the randomized CLASS trial, Br J Surg, 2014 , 101, 12, 1532-1540, doi: 10.1002/bjs.9595.

  3. Results

    Brittenden J, Cotton SC, Elders A, Tassie E, Scotland G, Ramsay CR, Norrie J, Burr J, Francis J, Wileman S, Campbell B, Bachoo P, Chetter I, Gough M, Earnshaw J, Lees T, Scott J, Baker SA, MacLennan G, Prior M, Bolsover D, Campbell MK, Clinical effectiveness and cost-effectiveness of foam sclerotherapy, endovenous laser ablation and surgery for varicose veins: results from the Comparison of LAser, Surgery and foam Sclerotherapy (CLASS) randomised controlled trial, Health Technol Assess, 2015 , 19, 27, 1-342, doi: 10.3310/hta19270.

Additional files

Editorial Notes

05/09/2019: The following changes have been made: 1. Publication reference added. 2. The final enrolment number has been added from the reference. 07/06/2016: Plain English summary added.