Central Nervous System Embolization

The hospitals of Athens Medical Group have a special Department for Endovascular Neurosurgery – Interventional Neuroradiology.

It is a surgery or radiology branch, aiming to treat vascular diseases of the Central Nervous System (brain and spinal cord), that has rapidly developed during the last 25 years.

The principal characteristic of embolization is that it approaches the brain vessels through their own lumen (intravascularly) and not externally like in conventional surgery by conducting craniotomy.

This kind of internal access combined with HD angiographs, 3D imaging, micro-catheters, state-of-the-art micro-wiring and continuously advancing embolization materials enable the intravascular treatment of many diseases of the brain and spinal cord, with excellent results and very low complications rates.

The diseases predominantly treated with intravascular surgery are:

  • brain aneurysms, either ruptured with subarachnoid hemorrhage or unruptured,
  • AV malformations - fistulas of brain and spinal cord, ( and all over the body ),
  • arteriovenous fistulas of the dura mater, traumatic or automatic, arteriovenous fistulas of head and neck,
  • stenoses of intracranial vessels (carotid, middle cerebral artery, basilar artery, etc.),
  • extracranial vascular stenoses, ( carotid, vertebral, subclavian artery, etc )
  • ischemic stroke (acute or non-acute ) because of  cerebral vessel occlusion, (Stroke Unit)
  • vascularized tumors of the head, neck and spine as a preoperative or palliative therapy (meningiomas, schwannomas, paragangliomas, hemangioblastoma, angiofibromas), hemangiomas of the head, neck and spine as a single or supplementary therapy,
  • nosebleeds or others hard to control hemorrhages of the head and neck.
  • Petrous Sinus sampling with or without renal sampling
  • Superficial lesions, such venous angiomas, hemaggiomas etc.

The endovascular procedures for the above conditions have been established as a method of choice and are preferred because of their non-traumatic nature compared to conventional open surgery, their good long-term results and low complications rates.

The hospitals of Athens Medical Group are ready on a 24hour basis to treat any cases with the embolization method and with any kind of neurosurgical procedures deemed necessary. A great number of patients are annually treated in the hospitals with results comparable to those of international medical centers.

Brain aneurysms occur in cerebral arteries points wherein the wall has either a structural defect or receives additional pressure from blood flow. They are not congenital anomalies, but they do develop over a number of years in an artery that has some of the abovementioned predisposing factors. They are usually shaped like a bag that develops on the wall of the artery.

A brain aneurysm has a risk of rupture and internal bleeding (subarachnoid hemorrhage, intracerebral hematoma, etc.), which usually have serious repercussions for the patient and death. This is why when a ruptured aneurysm is diagnosed it should be treated the soonest possible.

Aneurysms were traditionally treated with craniotomy and their eventual exclusion with one or more special clips. This is a very serious surgery associated with significant risks. This is why today it is replaced by embolization a modern minimally invasive method, with excellent results and a very low complication rate.

Embolization is not conducted with craniotomy, but through the insertion of a thin micro-catheter through the femoral artery right inside the aneurysm sac. Then, special embolization coils are guided inside the aneurysm, until the sack is completely unclogged and the bloodstream stops.

The results of aneurysm embolization are excellent, with very low complication rates and involve minimal patient discomfort. Thus, on a global level, the first choice for the treatment of brain aneurysms is embolization while craniotomy remains a second choice for only a small percentage of cases that cannot be treated with embolization, for technical or anatomical reasons.

In general, these diseases are abnormal vessel connections, between arteries and veins. There are several types, depending on the angioarhitectural characteristics of these vessel connections. The clinical symptoms are most common headache, seizure and rarely dangerous hemorrhage, para or tetra paresis/plegia etc.

When they are diagnosed, must be treated by one or more embolizations, with super-selective micro-catheterisation of the feeding arteries  and using liquid materials ( GluBran2, onyx ). The complication rate is very low (less than 2% ).

Our experienced intervention team, will study the patient files and than will propose the treatment program (if there is a need for more than one embolizations ).

Stenoses

Patient with intracranial or extracranial stenosis, must be in therapeutic protocol  (conservational, surgical or intervention ).

The kind of the therapeutic option depends on the clinical, anatomical and imaging findings. It will be decided  from the neuro team, for each patient separately, to prevent minor or large vessel occlusion and infract – stroke.

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Director of Neurosurgery Department

Dr. Michail Karygiannis, MD

Director of the Interventional Neuroradiology Dept.

  • Member of CIRSE and WFITN
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Neurosurgeon, Interventional Neuroradiologist

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News By Page

05.07.15
Intra-arterial Therapy in acute ischemic stroke incidents the department of invasive Neuroradiography of the Athens Medical Center pioneer in Greece, successfully implementing modern endarterial techniques

Written by Karygiannis Michail MD, Interventional Radiologist - Neuroradiologist, Director of Interventional Neuroradiology Department,  Athens Medical Center, Athens Medical Group

Introduction

Worldwide, over the last 5 years, special centers and medical units for the treatment of patients with acute ischemic stroke have been organized. This is because the contribution of intra-arterial interventions to address those with acute ischemic strokes is continuously enhanced and developed. The Interventional Neuroradiology department of the Athens Medical Center has performed the largest number of surgeries in Greece, with results corresponding to those of major European centers.

Strokes are the most important cause of disability in adults and one of the leading causes of death worldwide. In our country it is estimated that each year there are 30 to35 thousand new strokes, while total hospital admissions due to strokes exceeds 40 thousand annually. Strokes, beyond the urgency of the situation that must be handled, have serious physical, mental, social and economic consequences not only for patients but also their families.

Strokes are distinguished in ischemic strokes, which are more frequent and are 85% of total strokes, and hemorrhagic strokes (15%).

Ischemic strokes (IAEE) occurs when the arterial blood supply is interrupted in a portion of the brain. This is due to obstruction of large arteries in the brain or of small arteries within the brain. The obstruction is caused by either creation of a clot in an artery stenosis (thrombosis), or a clot formed normally in the heart that moved in the brain arteries by blood flow (embolism).

However, the functioning of brain cells requires a continuous supply of oxygen and glucose in the bloodstream. When the blood supply to part of the brain is interrupted by a stroke, a disturbance in the functioning of brain cells is caused and then these cells die.

In acute ischemic stroke, immediate treatment is necessary to prevent the spread of damage to a larger area of the brain, where the blood supply is reduced but has not stopped.

Symptoms of ischemic stroke

When brain cells do not have sufficient oxygen, they cease to perform their usual “duties”, in other words their functions. Symptoms following a stroke depend on the area of ​​the brain that is affected and the extent of the damage. When any of the following stroke symptoms appear suddenly, medical assistance should be immediately requested.

  • Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
  • Sudden confusion or difficulty in speaking or understanding
  • Sudden difficulty in sight of one or both eyes
  • Sudden dizziness, loss of balance or coordination of movements

It is important that if any of these symptoms of stroke occur, to visit a doctor as soon as possible. This is because the possibility of therapeutic intervention in patients with acute ischemic stroke is directly dependent on the time between the onset of symptoms and the start of treatment.

Treatment

The restoration of blood flow in the occluded cerebral artery, especially within the first 6 hours, results in an increase (4-5 times) of functional recovery and a reduction of the risk of death (up to 5 times). 

Patients who manage to go to an organized stroke center that and are subjected to the necessary laboratory and imaging tests for up to 4,5 hours after the onset of symptoms, are able to receive intravenous thrombolytic therapy (administration of a substance that dissolves the clot).

The time window of 4,5 hours is very limited and most times patients with stroke do not arrive at the hospital in time or have contraindications for the use of this medicine.

40% of ischemic strokes involve a large degree of occlusion of the cerebral vessel (such as the internal carotid artery, the main artery, the middle cerebral artery) with mortality rates between 30% and 90%. In these patients the response to intravenous administration of thrombolytics is unfortunately very small.

The need to extend the therapeutic time window from the onset of stroke and the treatment of patients with occlusion of the large blood vessels, led to the development of intra-arterial therapy, which includes intra-arterial thrombolysis and intra-arterial thrombectomy or mechanical thrombolysis.

Intra-arterial thrombolysis (effusion of thrombolytic substance directly into an occluded artery) can be applied for up to 6 hours after the onset of the symptoms of stroke, providing a 60% chance of opening of the occluded artery.

Intra-arterial thrombectomy or mechanical thrombolysis (clot removal) can be applied for up to eight hours (up to 12 hours in the posterior circulation) after the onset of stroke symptoms, offering a 80% probability of opening of the occluded artery.

Intra-Arterial therapy

Indications

  • Patients who completed their laboratory examinations (neurologic assessment, blood tests and imaging) after 4,5 hours and before 8 hours from the onset of stroke symptoms
  • Patients administered intravenous thrombolytic substance within 4,5 hours and showed no improvement
  • Patients with a contraindication to administration of thrombolytic substance
  • Patients with occlusion of a large artery and imaging indicating enhancement of a region of the brain with no necrosis, but at risk

Technique

Intra-arterial thrombolysis is performed under fluoroscopic monitoring (Digital Angiography) after puncture of the femoral artery, as is diagnostic digital angiography. Then, a guiding catheter (thin tube with a diameter of 2 mm) is advance to the carotid artery or vertebral artery (central arteries of the brain located in the neck) that supply the occluded cerebral artery. Through the guiding catheter, a microcatheter is advanced up the artery with the clot and the thrombolytic substance (r-tPA) is thereby effused directly to the thrombus.

In intra-arterial thrombectomy, the procedure followed for placement of the guiding catheter is the same as that of intra-arterial thrombolysis described above, but, with the guiding catheter an apparatus is advanced, which captures the thrombus, and then device and thrombus are removed from the artery.

The intra-arterial therapy surgery is usually performed under general anesthesia. Many times a combination of intra-arterial thrombolysis and thrombectomy is performed. Thus, depending on the artery blocked, thrombectomy is done when thrombolysis is not efficient or thrombolysis is done after thrombectomy so as to dissolve small clots in thin peripheral arterial branches.

The department of Interventional Neuroradiology at the Athens Medical Center has been in operation since 2001, having performed more than 1.500 surgeries. It has a digital angiogram of modern technology, is staffed by specialized and experienced personnel (doctors, radiology technologists, nurses) and covers emergencies 24 hours a day.    

Michael Karygiannis, Interventional Radiologist - Neuroradiologist Sci. Head of Interventional Neuroradiology Athens Medical Center.

09.01.15
Intra-arterial treatment at acute ischemic stroke

Dr. Michail Karygiannis, MD Director of Interventional Neuroradiology Department.

The Interventional Neuroradiology Department of Athens Medical Center is pioneering in Greece, applying modern endovascular techniques.

Over the last 5 years, stroke units are developing worldwide for better treatment of acute ischemic stroke patients. The contribution of intra-arterial interventions in the management of these patients is constantly been reinforced and evolving. The Interventional Neuroradiology department of Athens Medical Center has made the greatest number of such interventions in Greece, with excellent results similar to major European centers.

Introduction

Stroke is the first cause of disability in adults and a major cause of death worldwide. In our country it is estimated that each year there are 30,000-35,000 novel strokes, while total hospital admissions exceeds 40,000 patients annually.

Acute ischemic stroke is a major public health problem causing serious physical, mental, social and economic consequences for the survivors and their families.

Strokes are divided into ischemic, which is most often (constitute 85% of all strokes) and hemorrhagic (15%).

Ischemic stroke occurs when the arterial blood supply is interrupted in a part of the brain. This is due to obstruction of large arteries supplying the brain or small arteries within the brain. The obstruction is been caused by either clot formation in a cerebral artery stenosis (thrombosis), or thrombus, usually originating from the heart and migrating in a brain artery by blood flow (embolism).

The brain cell’s function requires a continuous supply of oxygen and glucose through the bloodstream. When the blood supply to any part of the brain is interrupted, it is causing functional disorders of the brain cells and subsequently necrosis.

In acute ischemic stroke immediate treatment is necessary to prevent expansion of the damage over a larger area of the brain where the blood supply is reduced but not stopped.

What are the symptoms of ischemic stroke?

When brain cells are deprived of oxygen, they cease to perform their normal duties. The symptoms following a stroke are dependent on the area of the brain that is affected and the extent of damage. When any of these symptoms appear suddenly, the patients should seek for medical help, immediately.

  • SUDDEN numbness or weakness of face, arm or leg, especially in one side of the body
  • SUDDEN confusion, trouble speaking, or understanding
  • SUDDEN trouble seeing in one or both eyes 
  • SUDDEN trouble walking, dizziness, loss of balance or coordination
  • SUDDEN severe headache with no known cause

The possibility of a therapeutic intervention in patients with acute ischemic stroke depends on the time between the onset of symptoms and the application of treatment.

Treatment

The restoration of blood flow in the occluded cerebral artery (especially in the first 6 hours) is associated with an increase (5.4 fold) of functional recovery and reduced (4-5 fold) of death.

Patients been able to get transferred in a stroke unit, after undergoing the necessary laboratory and imaging evaluation up to 4.5 hours after symptom onset, are eligible to receive intravenous thrombolytic therapy (administration of a substance that dissolves the clot).

The time window of 4.5 hours is very limited and often patients do not arrive in time to the hospital or have contraindications to the use of this type of treatment.

Additionally, 40% of ischemic cerebral infarctions are related to a large vessel occlusion (such as internal carotid artery, basilar artery and middle cerebral artery) with mortality rates of 30-90%. In these patients the response to intravenous thrombolytic therapy, unfortunately, is very small.

The need to extend the time window and the therapeutic response of patients with large vessel occlusion has led to the development of intra-arterial therapy which involves intra-arterial thrombolysis and intrarterial thrombectomy or mechanical thrombolysis.

The intra-arterial thrombolysis (thrombolytic infusion substance in an occluded artery) can be applied up to 6 hours after onset of symptoms, providing 60% probability of revascularization (opening) of the occluded artery.

The intra-arterial thrombectomy or mechanical thrombolysis (clot removal) can be applied up to 8 hours (up to 12 hours in the posterior circulation) after the onset of symptoms, offering 80% chance of opening the blocked artery.

Intra-arterial therapy

Indications

• Patients with acute ischemic stroke who completed the clinical and laboratory controls (neurological assessment, blood tests and imaging evaluation) after 4.5 and before 8 hours from the onset of symptoms.

• Patients with stroke initially treated with intravenous thrombolytic drug within 4.5 hours and showed no improvement.

• Patients with stroke and contraindications to administration of thrombolytic substance.

Technique

The intra-arterial thrombolysis is performed under fluoroscopic control and puncture of the femoral artery as in a diagnostic angiography. Then a guiding catheter (thin 2 mm diameter tube) is advanced into the carotid artery or vertebral artery (main arteries of the brain located in the neck) which feeds the occluded cerebral artery. Through the guiding catheter, a microcatheter is advanced up to the artery where the clot is located and thrombolytic substance (r-tPA) injected directly to the thrombus.

In the intra-arterial thrombectomy, the guiding catheter installation procedure is identical to the one described above, but through the guiding catheter a special device is advanced which captures the thrombus. Finally thrombus and the device are removed from the artery.

The procedure is usually performed with the patient under general anesthesia. Sometimes a combination of intra-arterial thrombolysis and thrombectomy is been applied.

The Interventional Neuroradiology Department at Athens Medical Center operates since 2001, having performed more than 1,500 interventions. The department uses innovative technology and is been staffed by qualified and experienced personnel (doctors, radiology technologists, nurses) and covers emergencies 24 hours a day/7 days per week.