Table 1 Inclusion criteria International Carotid Stenting Study (ICSS)

Inclusion criteria

- Symptomatic, extracranial, internal or bifurcation, atheromatous carotid artery stenosis that is suitable for both stenting and surgery and is deemed by the randomising clinician to require treatment.

- The severity of the stenosis of the randomised artery should be at least 50% (as measured by NASCET method or non-invasive equivalent).

- Symptoms must have occurred in the 12 months before randomisation. It is recommended that the time between symptoms and randomisation should be less than 6 months, but patients with symptoms occurring between 6 and 12 months may be included if the randomising physician considers treatment indicated.

- The patient must be clinically stable following their most recent symptoms attributable to the stenotic vessel.

- Patients must be willing to have either treatment, be able to provide informed consent, and be willing to participate in follow-up.

- Patients must be able to undergo their allocated treatment as soon as possible after randomisation.

- Any age greater than 40 may be included. There is no upper age limit.

- Patients should only be randomised if the investigator is uncertain which of the two treatments is best for that patient at that time.

Exclusion criteria

- Patients refusing either treatment.

- Patients unable or unwilling to give informed consent.

- Patients unwilling or unable to participate in follow-up for whatever reason.

- Patients who have had a major stroke with no useful recovery of function within the territory of the treatable artery.