Making a bypass in the brain is sometimes the last treatment option in very ill patients. Conventional bypass techniques are accompanied by high ischemic risks because an artery in the brain has to be temporary closed to attach the bypass with sutures.

The ELANA technique, invented by professor Tulleken from the University Medical Center (UMC) in Utrecht, The Netherlands, circumvents this problem. The technique facilitates the construction of a bypass without the need to temporarily close the recipient brain artery. The technique is mostly used to treat giant intracranial aneurysms (aneurysms more than 2.5 cm wide) or to give new blood supply to patients with an occluded artery to the brain (ischemia).

Giant intracranial aneurysms

In a recent report (‘Neurosurgery’, van Doormaal et al, October 2006) is shown that it was possible to create a patent high flow Extra- Intracranial ELANA bypass in 93% of 34 patients with a giant internal carotid artery (ICA) aneurysm treated in the UMC Utrecht (Figure 1). Mean flow was 124 cc/ min. Of these patients 74% had a long term (mean 3.3 years) favorable outcome (defined as independent and the same or a better functionality as preoperative). Recent research (accepted for publication in ‘Neurosurgery’, van Doormaal et al) shows that in 91% of patients with a giant middle cerebral artery (MCA) aneurysm it was possible to create a patent bypass (92% Intra- Intracranial bypasses, mean flow 56 cc/min) (Figure 2). At long term follow up (mean 3.6 years), 77% of these patients had a favorable outcome.

Figure 1: A giant ICA aneurysm (red arrow, lef angiogramt) is bypassed with a Ec-Ic bypass with a proximal anastomosis on the ECA and a distal ELANA anastomosis on the ICA bifurcation (green arrow, middle and right angiogram). Postoperatively, the ICA was occluded with a detachable balloon (blue arrow, right angiogram). Patient recovered perfectly.

Figure 2: Giant right sided MCA aneurysm (left angiogram). Ic-Ic bypass with a proximal ELANA anastomosis (red arrow) and a distal conventional anastomosis (right angiogram). The aneurysm was trapped (proximal and distal aneurysm clip on the MCA) during the same procedure. Patient recovered with maximum functional health (mRankin 0)

Figure 3: Giant left sided MCA aneurysm (Left and middle angiogram). IC-IC bypass with proximal and distal ELANA anastomosis (red arrows). Aneurysm was trapped, patient recovered without any morbidity(mRankin 0)

Also giant aneurysm of the Anterior Cerebral Artery, the Anterior Communicating artery, and even the basilar and vertebral artery were treated with an ELANA bypass. These are very challenging procedures in which ELANA has been proven to be a valuable addition to the treatment armamentarium of the vascular neurosurgeon. For more questions about this topic please refer to Dr B. van der Zwan or Prof. dr C.A.F. Tulleken, please use the following link: Contact

Ischemia of the Brain

The ELANA research group is in process of analyzing the retrospective data of 63 patients with carotid and MCA occlusions (example: figure 4). It seems that the outcome is profitable for patients and therefore justifies a pilot trail to compare an Ec-Ic ELANA bypass to the conventional Ec-Ic STA-MCA bypass in a selected group of ischemic patients with hemodynamical cerebral ischemia. This trail is probably going to take of in the UMC Utrecht approximately medio 2008.

Figure 4: A 62 year old male suffered since 6 months from attacks of severe weakness in his right leg and arm, occurring every week. He had continuously an unstable gait and dysphasia.

1st from Left: The CTA shows an occluded ICA(red arrow). 2nd image: Intraoperatively the ICA showed severe calcification. This is not a suitable spot for any anastomosis. 3rd image: However, the ACA showed a healthy looking spot, suitable for an ELANA anastomosis. The 2.6 ring shown was used. Right image: External carotid artery to anterior cerebral artery bypass with 230 cc/min flow (MRF measurement). Patient had no complications, within 3 weeks he was playing golf again and his speech was significantly improved.

Also in bypass surgery for patient with hemodynamic cerebral ischemia, the ELANA bypass seems a valuable addition to the treatment armamentarium of the vascular neurosurgeon. For more information and patient referral, please contact Prof. A. van der Zwan. Use the following link: Contact

Intracranial tumours

For a small subset of tumours of the skull base an ELANA bypass could be indicated if the recipient vessel does not tolerate occlusion time. For example meningeomas which compromise the ICA lumen. Several successful operations were performed by professor Tulleken and his team in Utrecht. For more information on this subject please contact Prof. A. van der Zwan. Use the following link: Contact


In neurosurgery currently a revival of bypass surgery is taking place with the appreciation of the fact that a certain subset of patients with aneurysms, ischemia or tumours remain untreatable despite advances in neurological treatment and neuroradiological intervention techniques. In the future different specialities will cooperate to treat this very difficult patients. For example an ELANA bypass will more frequently be combined with stenting or other neuroradiological procedures to treat difficult aneurysms like giant basilar artery aneurysms or other growing aneurysms filled with coils. ELANA will be performed in a simpler, possible minimal invasive way. When this is developed, other fields like the coronary bypass grafting will benefit from the advanced ELANA prccedure beause of the ease of use and the lack of occlusion time for the patient and time pressure for the surgeon. For more information on these and other research subjects, please use the following link: Contact