Excimer laser-assisted nonocclusive anastomosis

Excimer laser assisted nonocclusive anastomosis (ELANA) is a technique in vascular surgery and neurosurgery to create a bypass without interrupting blood supply in the recipient blood vessels.

The ELANA technique is a subtle modification of existing methods to establish a connection between blood vessels (anastomosis) to create a bypass in or to the brain. The only real differences involve how the recipient artery is opened. In conventional techniques the recipient artery is temporarily interrupted (occluded with clips) and opened using microscissors or scalpel while in the ELANA technique blood flow is not interrupted and the opening (arteriotomy) is created with radiation from a 308nm Excimer Laser delivered through a catheter inserted in the vessel that will become the bypass while blood continues to flow through the artery that receives the bypass. This subtle difference, however, is very important for the safety of the procedure and eliminates the risk of ischemia to the regions supplied by the artery receiving the bypass. The technique is most valuable in neurosurgery, as brain cells are particularly sensitive to the lack of blood supply (ischemia) that would be caused by traditional methods of bypass creation. The bypasses created with the help of the ELANA can be to one of the major arteries in the brain (extracranial to intracranial EC-IC bypass) or between two arteries in the brain (intracranial to intracranial).

Surgeons are creating such a bypass mainly as a step in the treatment of patients with unclippable and uncoilable giant aneurysms or tumors at the skull base or to treat patients at risk of stroke who can not be treated otherwise.

The ELANA technique has been extensively described in medical literature. It was developed in 1993 by Cornelis A.F. Tulleken, professor of neurosurgery at the University Medical Center Utrecht, the Netherlands, to find a way to treat patients with a bypass to a major cerebral artery without the risk of cerebral ischemia during the procedure. The surgery of some patients has been reported upon in the media e.g., in The New York Times in December 2006.