Low Morbidity after Extracranial-Intracranial Bypass Operation. The Danish Extracranial-Intracranial Bypass Study: A Nationwide Survey

BACKGROUND: Patients with symptomatic atherosclerotic carotid artery occlusion (SACAO) have a high risk of a recurrent stroke. Extracranial-intracranial bypass (EC-IC bypass) has been shown not to improve outcome compared with medical treatment alone because long-term prevention of recurrent stroke in operated patients was offset by high perioperative stroke rates. We report our experience with EC-IC bypass operated at an experienced high-volume centre.

METHODS: We conducted a nationwide observational study of EC-IC bypass patients operated in the years 2007-2016 due to SACAO with ongoing clinical symptoms or progression on MRI and severe haemodynamic failure (SHF). Perioperative stroke and death within 30 days after the operation, ipsilateral stroke, bypass patency, transient ischaemic attack, and all-stroke events and deaths during long-term follow-up were registered prospectively.

RESULTS: EC-IC bypass was performed in 48 patients with SHF and SACAO. The mean age was 64 (45-83) years. The mean follow-up was 3.6 years. The stroke rate after 30 days was 4.2%. No further ipsilateral strokes occurred during follow-up. Clinical symptoms arrested in all patients. Bypass patency rate was 94%.

CONCLUSIONS: The perioperative stroke rate in EC-IC bypass operation, performed at a highly experienced centre, was low. During long-term follow-up, no ipsilateral stroke occurred. Consequently, EC-IC-bypass should still be considered for selected patients with SACAO, if operation can be carried out in experienced centres with low perioperative morbidity.