BTI has various research projects that are ongoing and which will likely result in new/ better tools and treatment options for neurosurgical patients.

Elana Clip 3.0

Development of a sutureless clip to make the Elana technique easier and faster and hence safer for the patient. Through the use of this Clip device it is no longer necessary to make sutures deep in the brain in order to make a bypass without temporary occlusion of the blood flow. Through this clip the OR time of such a bypass surgery will decrease significantly which obviously will benefit the patient. During the last few years a PhD student of the neurosurgical department of UMC Utrecht,  Bart de Boer, has intensively tested this newly developed device in various laboratory settings at BTI and has been used in a clinical trial setting, to treat patients with an aneurysm or tumor that need the be treated with a non-occlusive bypass technique.



Mathematical flow model

Development of a mathematical model to predict flow in major cerebral arteries. A model of the exact blood flow in the arteries of the brain that can be clinically used does not yet exist and such a model and will provide tremendous insight on e.g. the best location for a bypass in the brain and can impact / improve the treatment options of patients with different types of cerebrovascular disease.

This research takes place by PhD student Jasper Helthuis, in collaboration with UMC Utrecht and the Indian Institute of Technology Madras (IITM) in India. The Dutch and Indian authorities approved a 4-year research grant.



Mid-size arteries

Implementation of a new sutureless clip to make a non-occlusive bypass in the brain on mid-size arteries. The current Elana Surgical Kit (see link a) and the newly developed Elana Clip (see link b1) can only be used on the large vessels in the brain on patients that can not tolerate a conventional bypass where the blood flow is temporary being occluded.  However, there is still a (small) group of patients that is eligible for an Elana bypass, but cannot be treated with this technique because of the fact that the size of their blood vessel where the bypass needs to be placed is too small. Up till today these patients are being treated with a conventional bypass, which creates a relatively high risk of stroke or other serious complications. In collaboration with PhD student Kiki Gortzak, BTI is now developing and implementing a smaller, oval clip device. Through such a device a new group of patients with an aneurysm, tumor or ischemia can benefit from a safer, non-occlusive sutureless bypass technique. See below animation:



BTI is proud to collaborate with Polyganics b.v. on the development of a scientifically proven, watertight dura sealant to prevent cerebrospinal fluid (CSF) leakage after durotomy (incision of the tough, outer membrane of the brain and spinal cord).

The brains and spinal cord are being protected by the dura. In about 30% of the neurosurgical procedures, the dura needs to be opened to reach the underlying tissue. In order to close the dura after opening it, neurosurgeons often use sutures and/or a sealant. However, currently there is no unambiguous solution to close the dura watertight since CSF leakage is one of the most common complications of neurosurgical procedures. Preclinical research has been conducted at BTI by a PhD candidate to a new cranial dural sealant, which has resulted in the start of a clinical trial in Europe to LIQOSEAl in the ENCASE study. Currently preclinical research at BTI is being conducted to the spinal application of this dural sealant.

BTI and Polyganics received a grant from the Netherlands Enterprise Agency  for the collaborative research project.

HoloLens application for neurosurgery

Together with software specialist Infosupport and the department of neurosurgery of the UMC Utrecht, BTI is developing an application of Mixed Reality in neurosurgery. With the consortium we developed an innovative HoloLens application which enables with great precision the projection on a patient of a hologram of the brain, including blood vessels, aneurysms, tumors and other (ab)normalities. Such a tool  has three possible applications:

1.     Provide information to patients and their families: through the use of a hologram it will become much easier to inform and show the patient in 3D visualisation where the problem is located and how it will be treated during surgery.

2.     Education of neurosurgeons: the HoloLens application can be used to prepare and train young neurosurgeons / residents on specific complex treatments

3.     Navigate during surgery: through the use of the HoloLens application the relation of various structures such as tumors and blood vessels can be shown in a 3D manner,  which enables the neurosurgeon with an extra tool to prepare him/herself for the surgery and to perform specific parts of the surgery in a better way.

Upon conclusion of all research activities, this neuronavigation application will be certified for clinical use.



Moyamoya is a progressive cerebrovascular disorder in which the large arteries in the brain (the internal carotid, the middle cerebral and the anterior cerebral artery) narrow or even occlude. What causes this vasculopathy remains unknown. Moyamoya is the Japanese word for a ‘puff of smoke’, derived from the characteristic appearance on angiography. The disease may cause ischemic or hemorrhagic stroke. Furthermore, patients may present with symptoms like headache, epilepsy and cognitive disorders. Treatment that may halt progression of the disease or even reverse the vasculopathy is yet to be found, however neurosurgical revascularization by performing direct and indirect bypass surgery can reduce the risk of stroke and cognitive dysfunction by improving cerebral perfusion. The moyamoya research group has set up a scientific program with the following main objectives:

  • Etiology (what causes the disease)
    The development of new and improvement of already existing radiological examinations to characterize the vessel wall abnormalities in moyamoya (vascular wall imaging with high resolution 7-Tesla MRI)

  • Cognitive functions

    • the correlation between the severity and location of pre-operative cerebral perfusion abnormalities and cognitive functions

    • the influence of bypass surgery on the cerebral perfusion and cognitive functions

Although the condition is very rare, PhD student Annick Kronenburg, together with the research group has the ability through its nationally recognized expertise to conduct scientific research on this disease for a relatively large patient population. Furthermore, through on-going international collaborations with several moyamoya centers, a unique opportunity is created to gain knowledge in the field of moyamoya on both scientific and clinical fields. Our research group focuses on optimizing treatment, aiming to improve the outcome and the quality of life. As a result, the future of these mostly young patients (with a high risk of stroke) may be improved significantly. 


New Intelligent Neuronavigation for Skull Base Surgery: EVADE

During skull base surgery, (neuro)surgeons aim to drill through the skull carefully to optimize the subsequent removal of an underlying brain tumor while preserving surrounding vital structures, such as blood vessels and nerves. During drilling, computer navigation can help surgeons to maintain optimal orientation.  Current navigation systems are restricted to provide information about the position of surgical instruments within astatic scan of the patient’s made before surgery. Although useful, this information still has limited value for surgeons.

Therefore, the research group aims to improve the navigation system’s information relay to surgeons so they can optimize their surgery.  Our custom designed navigation system - called EVADE - updates the patient’s scan to show bone drilling in real time, and meanwhile continuously calculates the distance of the drill tip to critical nerves and blood vessels, emitting warnings when the drill tip comes in close proximity. You could see it as an intelligent ‘car parking assistant’ or a ‘digital deputy’ for the neurosurgeon.

The goal of this research project, which is conducted by PhD student Eduard Voormolen, is to design, develop, and evaluate the proposed system and validate it for use in patients. 

The thesis of Eduard Voormolen 'Computer-Assisted Surgery of the Skull Base -  Contributions to Guidance and Imaging' can be found here.