Endovascular surgical treatment (closed surgery) of cerebrovascular diseases like cerebral aneurysm, stroke, arteriovenous malformations (vascular tangles) and carotid stenosis is conducted at quite high success rates at our Interventional Neuroradiology unit. Furthermore, international academic studies aimed at development of novel endovascular treatment techniques and methods are undertaken.   

Our clinic is a national reference center that receives referrals of complex cases and specializes particularly in endovascular treatment of cerebrospinal vascular diseases. Presenting or referred to our clinic with conditions such as aneurysm, arteriovenous malformation and carotid stenosis, patients go through the necessary investigations and are then evaluated in depth for treatment planning by our neurovascular team, which consists of internationally renowned specialists of interventional neuroradiology, neurosurgery, radiosurgery (gamma knife) and neurology. Cases requiring combined treatment are evaluated by our neurovascular team accordingly. 

The Interventional Neuroradiology Department of Koç University School of Medicine is recognized globally in terms of clinical and academic research and also as a leading national reference center in Turkey.


Service Subcategories of Interventional Neuroradiology

Acute stroke therapy

Stroke implies sudden loss of one or several of the speech, movement, sense and comprehension functions as a result of sudden occlusion of one or more arteries supplying the brain. The most commonly encountered symptoms of stroke include facial paralysis, unilateral shifting of the lips, numbing in one half of the body or arms, strength loss, lisping and inability to speak. Treatment of stroke within 6 hours following the onset of symptoms can ensure that the patient does not sustain permanent disability. Treatment of stroke where a cerebral artery is occluded by a blood clot is performed with a special stent designed for extraction of such clots. This procedure is called thrombectomy. The thrombectomy procedure can be performed 7 days/24 hours at our interventional neuroradiology clinic. Similar to other endovascular operations, treatment of thrombectomy is carried out by our specialized team utilizing cutting edge device and medical equipment.


Cerebral aneurysms

An aneurysm is ballooning that occurs in a weak spot of the brain’s arteries. Cerebral aneurysms might potentially burst at a fragile point, resulting in a type of intracranial hemorrhage known as subarachnoid hemorrhage, which is a severe and life-threatening medical condition. Approximately 35% of patients experiencing subarachnoid hemorrhage lose their lives. On the other hand, we are able to diagnose and endovascularly treat the majority of cerebral aneurysms before they burst and cause intracranial hemorrhage. It is essential to close the aneurysm in patients who have experienced an intracranial hemorrhage. Along with novel techniques devised within the past 20 years, endovascular treatment methods have become the primary option in treatment of aneurysms. 

Carotid stenosis

Carotid arteries are two of the 4 essential vessels supplying blood to the brain. The disease of atherosclerosis often impairs carotid arteries with stenosis and occlusions, which in turn prevent adequate blood from being supplied to the brain and might consequently cause palsy/stroke. Stenoses building up in carotid arteries lead to temporary ischemic attacks, which last less than 24 hours and subside on their own. Temporary ischemic attacks trigger symptoms like formication, numbing and weakness in legs and arms; speech disorder; difficulty making out words; lisping; sudden loss of vision in one eye; shifting in one half of the face and lips; and dizziness. These attacks are precursors of an impending permanent palsy attack. Medical treatment proves to be insufficient if the level of stenosis in a carotid artery is over 70 percent, in which case additional interventional treatment is required. Stenting and balloon angioplasty are reliable and effective methods in treatment of carotid stenosis. 

Arteriovenous malformations (AVM)

Arteriovenous malformation is a cerebrovascular condition where multiple vessels of abnormal morphology get tangled up. AVM causes high blood flow velocity inside that gradually causes vessel walls in the tangle to weaken. Over time, one of the vessels constituting the tangle might burst and result in intracranial hemorrhage. Overall, AVM is not accompanied with any complaint in 25% of cases and is incidentally diagnosed in imaging studies like MRI, which may originally be performed for other reasons. The other 75% of the patients will experience headache, epilepsy (seizures), numbing in arms and legs, weakness and speech difficulty. Endovascular treatment (embolization), open surgery and radiosurgery are the primary treatment methods for arteriovenous malformation. AVM treatment should be carried out by taking into account numerous factors and handled by a team of neurosurgery, interventional neuroradiology and radiosurgery specialists. Some patients may require combined therapies where two or even three different techniques are practiced consecutively. 

Arteriovenous fistula (AVF)

Arteriovenous fistula is a condition characterized with a direct connection that forms between an artery and vein. As a result, the high-pressure blood in an artery passes through a vein and leads to elevated venous pressure in the brain or spinal cord. The high pressure in the vein eventually tears the vein and could cause intracranial hemorrhage. In other cases where there is no intracranial hemorrhage, the high venous pressure prevents the brain and spinal cord from receiving sufficient blood, leading to complaints like weakness, speech disorder, inability to urinate and stroke. Arteriovenous fistulas of the brain and spinal cord are treated by means of endovascular methods. Some patients may require open surgery as well.


  • Brain bubbles (aneurysm)
  • Endovascular treatment of aneurysms (closed surgery)
  • Cerebrovascular tangles (arteriovenous malformations / AVM)
  • Endovascular treatment of cerebral AVM
  • Spinal vascular tangles (spinal AVM)
  • Dural arteriovenous fistulas (dural AVF)
  • Arteriovenous fistulas of the spinal cord (spinal AV)
  • Carotid-cavernous fistula (CCF)
  • Carotid stenosis/occlusion 
  • Cerebrovascular stenosis
  • Endovascular stroke treatment (thrombectomy)
  • Tumor embolization
  • Intra-arterial chemotherapy in retinoblastomas