Neurointerventions is known by many other names such as Endovascular Neurosurgery/Interventional neurology/ Interventional Neuroradiology/Neurointerventional surgery. It is a subspecialty of neurosciences which deals with minimally invasive diagnostic and therapeutic interventionfor pathologies of brain and spinal cord.  It mainly deals with vascular pathologies of the central nervous system like stroke, brain hemorrhage, aneurysm, arterio-venous malformations etc.

Neurointervention involves using advanced imaging technology along with specially designed minute catheters and devices through the blood vessels to remove clots or blockage, open the narrowed blood vessels or close the leaking or abnormal ones. Since all these procedures are done by a small needle puncture over the blood vessel in the thigh/groin (femoral artery) or wrist (radial/ulnar artery), they are said to be micro-invasive and practically non invasive to the brain.

Advantages:

• Minimally / micro invasive
• Painless
• No open surgery, no scar
• Minimal risks
• Minimal injury to brain
• Faster recovery
• Short hospital stay
• Can be performed even in patient with co-morbid conditions or high risk for anesthesia/ open surgery

SERVICES/ TREATMENTS

1. Cerebral angiogram /DSA (Digital Subtraction Angiography)
2. Spinal DSA(Digital Subtraction Angiography)
3. Balloon test occlusion

4. Mechanical thrombectomy for acute strokeAneurysm treatment

   a. Simple Coiling

   b. Balloon assisted coiling

   c. Stent assisted coiling

   d. Flow diverter

   e. Intrasaccular device - Web or contour device

5. Embolisation

   a. Brain AV malformation (bAVM)

   b. Cranial dural AV fistula (dAVF)

   c. Carotico-cavernous fistula (CCF)

   d. Spinal AVM/ AVF

   e. Scalp AVM

6. Angioplasty and stenting for stenosis

   a. Carotid angioplasty/stenting

   b. Vertebral artery/stenting

7. Intracranial angioplasty and stenting for ICAD
8. Tumor embolisation
9. Middle meningeal artery embolisation for Chronic SDH
10. Cerebral venous sinus thrombosis – thrombectomy/in-situ thrombolysis
11. Venous sinus stenting in stenosis leading of intracranial hypertension
12.  

Diagnostic procedures:

1. Cerebral DSA

                   It is a diagnostic study of blood vessels of the brain. This is done by inserting a small catheter from thigh or hand into the brain vessels and injecting a contrast agent/dye to study the anatomy and flow of the vasculature of brain. This is commonly done under local anesthesia as a day care procedure.

2. Spinal DSA

                  Diagnostic study of blood vessels supplying the spinal cord. This involves studying various blood vessels starting from the head to the abdomen. It may take longer time and commonly done under general anesthesia.

3. Balloon test occlusion

                  Ligation or injury to carotid artery may be anticipated in many situations like oncosurgical procedures or head and neck. In such situations, likelihood of patient having neurological problems and need for a surgical bypass may be decided beforehand by performing a test occlusion of the artery. In this procedure, carotid artery is blocked temporarily using a balloon. Serial imaging and clinical assessment of the patient is done to see if patient can withstand the occlusion without problems up to 30-40minutes. This procedure is also done under local anesthesia so that the patient is awake for the clinical assessment during occlusion.

Therapeutic procedures:

Diseases commonly treated by Neurointervention are

1. Brain hemorrhage

                Spontaneous hemorrhage in the brain also called as hemorrhagic stroke may be either caused by sudden increase in blood pressure or due to underlying problems in the blood vessels. Patient commonly presents with sudden severe headache, vomiting, loss of consciousness, seizures, or stroke like symptoms.

Brain aneurysms and Arterio-venous malformations are the main treatable/ curable causes of brain hemorrhage.

• Aneurysm  :

                 Aneurysm is a balloon like dilatation or bulge in the blood vessels from a weak point. These are prone to rupture and may cause devastating bleeding / subarachnoid hemorrhage. Such patients need early treatment as there is high risk of rebleeding causing irreversible neurological damage.

Conventionally these aneurysms are treated by open surgical clipping of the aneurysm- by opening the skull and retracting brain.

Coiling of aneurysm is an option where in aneurysm is accessed by endovascular route, via a femoral or radial artery– and then platinum coils are filled into the aneurysm to occlude it, without opening skull. Endovascular treatment of aneurysm is safe, effective and has lesser risks compared to open surgical treatments.

Giant aneurysms or fusiform aneurysm which conventionally required morbid surgery like cerebral bypass and now the same may be treated in a minimally invasive way by Flow diverter placement.

Unruptured aneurysms - detected while undergoing scans for other reasons. These also are better treated, as they carry future risk of hemorrhage. Many such patients may be scared to undergo surgery as they have no symptoms at all, endovascular intervention is a risk free alternative in these patients also.

• Arterio-venous malformations of brain (bAVM)

                AVM is abnormal collection/ tangle of blood vessels between the arteries and veins. These vessels are leaky and may cause bleeding or sometimes irritate the brain surface and cause seizure.

Surgical resection is the gold standard treatment. However smaller AVMs, or AVM in eloquent / sensitive and deeper locations (not amenable for surgery) may be embolised. Some AVM may be complex and may need multidisciplinary approach – combination of embolisation, surgery and/or radiation therapy.

• Arterio-venous fistula (AVF)

               AVF are abnormal connection between the arteries and veins. These connections are prone to bleeding due to the high pressure and also steal blood from normal brain causing various problems. Patients can present with bleed, seizures, headache visual disturbances etc.

Endovascular embolisation with coils and liquid embolic agents is done to close this abnormal communication.

2. Ischemic stroke

                 Ischemic stroke refers to damage of neurons in the brain due to lack of blood supply. It may be caused by clotting in the blood vessels of brain or clots from heart or neck vessels embolising into the brain.

Symptoms of stroke include - sudden onset of any of the following

• Limb weakness or paralysis
• Facial asymmetry/ deviation
• Reduced or loss of vision
• Slurred or loss of speech
• Imbalance in gait/giddiness
• Loss of consciousness
• Rarely seizures/ convulsions

 Neural tissue is highly sensitive and cannot survive long without blood supply.  After block in blood flow, about 1.9 million neurons die every minute without treatment. Thrombolysis (an injection to dissolve the clot) is the first line of treatment for stroke. However it is effective in only up to 30% of patients and can be given in window period of first 3-4.5 hours of onset of stroke or occlusion.

 In case of large vessel occlusion, patient may end up in large stroke leading to death or coma without treatment. Mechanical thrombectomy is a procedure in which clot in the blood vessel of brain is aspirated or pulled out with use of a stent retriever to reestablish blood flow to the brain.

This procedure is a ray of hope in patients of large vessel stroke – who either don’t respond to thrombolysis or not eligible for the same due to late presentation. In selected eligible patients, mechanical thrombectomy may be performed even up to 24 hours after onset of stroke. However results are better in early recanalisation.

3. Carotid / Vertebral artery stenosis

                        Carotid and Vertebral arteries are main arteries carrying blood to the brain. Atherosclerosis in the artery may cause narrowing or stenosis of the artery causing reduced blood flow to the brain. These may rupture and cause complete block of blood supply to brain leading to major stroke or may have repeated minor strokes. Such patients may have warning symptoms of stroke, recovering in minutes (Transient Ischemic Attacks-TIA). Angioplasty and stenting can be done to prevent future stroke in patients at risk.

4. Carotico-cavernous fistula (CCF)

                        CCF is an abnormal connection between two major blood vessels in the brain – carotid artery and cavernous venous sinus. This may occur following trauma to the head (Direct CCF) or spontaneously (Indirect CCF)

They commonly present with redness and bulging/proptosis of eyes or vision loss. Endovascular embolisation is the only treatment available for most of these cases as there inaccessible to surgical ligation.

5. Cerebral venous sinus thrombosis (CVST)

                       Venous sinuses are the veins carrying blood back from the brain to the heart. Clotting of blood in veins of brain is called CVST. They may cause hemorrhagic infarct and bleeding in the brain. Patients present with headache, vomiting, seizures and stroke. Medical treatment – anticoagulation is first line of treatment. Some patient not improving with medical management may need intervention to remove the clots from the veins.

6. Middle meningeal artery embolisation

                       Chronic subdural hematoma is a delayed/ slow bleeding within the membranes surrounding the brain into a space called subdural space. The bleed may occur a few weeks following trauma to head or sometimes spontaneously in old age. Patients may present with headache, imbalance, speech difficulty, limb weakness or even mood disturbances.

This hematoma may drained surgically, however may have recurrence. Some patients may not be fit for surgery owing to old age or other co-morbid ailments/illnesses. Embolisation of middle meningeal artery from which the blood leakage occurs may be blocked or embolised to treat this problem without surgery or in addition to surgery to prevent recurrence.

7. Tumor embolisation

                       Tumors of the head and neck, especially the skull base are highly vascular and some are difficult to access and remove by surgery. Surgery may cause high amount of blood loss during surgery and risk morbidity and mortality. Is such patients especially with large vascular tumors, preoperative embolisation may help in safe and easier surgical resection with minimal blood loss and reduced risks during surgery.

8. Venous sinus stenting              

                        Venous sinuses or large veins carrying blood from brain, back to the heart may have some narrowing, leading to high back pressure in the brain. Patients may present with persistent severe headache, vomiting, blurred vision, and double vision – features suggestive of Idiopathic intracranial hypertension. An angiogram is done to check for amount of block in the veins and pressure gradient is measured to check for significance. If there is increased pressure difference across the blocked veins, such patients may have permanent relief is symptoms with stent and opening of the veins – easing the blood flow.

9. Intracranial angioplasty and stenting

                        Block or narrowing can happen even in the blood vessels within the brain due to atherosclerosis (Intracranial atherosclerotic disease – ICAD) or sometimes due to other problems of the blood vessels itself. Such patients having repeated strokes or warning symptoms – TIA, may require intracranial angioplasty with or without stenting of the same.

10. Embolisation of spinal AVM/ AVF

                       Spinal arterio-venous malformations are rare. These malformations may cause damage to spinal cord or neural tissue either by bleeding into it or by high back pressure (venous congestion). Patients may present with back pain, limb weakness, numbness, urinary retention or incontinence, constipation or fecal incontinence. Surgical ligation/ resection or Embolisation of these malformations can prevent devastating paraplegia and help in neurological recovery.