PRINCIPLES OF NEUROINTERVENTIONAL THERAPY

1. PRINCIPLES OF NEUROINTERVENTIONAL
THERAPY
PRESENTED BY DR CHITRALEKHA NAIK

3. ISCHEMIC STROKE
• Acute Stroke Treatment-
• Stroke is the leading cause of death and the
most common reason for disability worldwide

4. Indication and contraindication of thrombolytic therapy

6. Listed contraindications on FDA drug labeling for
Activase (alteplase) use for AIS
• Current intracranial hemorrhage
• Subarachnoid hemorrhage
• Active internal bleeding
• Recent (within 3 months) intracranial or intraspinal
surgery or serious head trauma
• Presence of intracranial conditions that may increase
the risk of bleeding (eg, some neoplasms,
arteriovenous malformations, or aneurysms)
• Bleeding diathesis
• Current severe uncontrolled hypertension
• AIS=acute ischemic stroke; FDA=Food and Drug
Administration

7. To improve reperfusion, many techniques have evolved including adjunctive
focused ultrasound therapy in IV rtPA and endovascular catheter-based
therapies
• Sonothrombolysis-adjunctive application of
continuous transcanial ultrasound to an intra-
arterial thrombus during IV rtPA
administration.
• This therapy is intended to enhance ability of
IV rtPA to dissolve clot

8. Combined Lysis of Thrombus in Brain ischemia using transcranial Ultrasound and
Systemic tPA (CLOTBUST) showed complete recanalization or dramatic clinical
recovery within 2 hours after IV rtPA bolus with continuous ultrasound in 31
patients compared with 19 pts in the control group(49% vs 30%; P = 0.03)

9. Endovascular Revascularization Therapy
Uses microcatheters (thin
tubes visible under X-rays)
which are inserted into the
blood clot from the groin or
the arm. The blood clot is
removed from blood vessel –
this procedure is called
a thrombectomy. If blood
clot cannot be removed, it is
liquefied using drugs
delivered through the
catheter, in a procedure
known as thrombolysis

10. The blood clot may be removed by trapping it in a stent which is then pulled out with
clot, or interventional radiologist may suck clot out through catheter. If the clot
cannot be removed, a medication may be applied through the catheter to liquefy it. If
the blood vessel is too narrow, a balloon catheter can be used to restore its original
size, in a procedure called an angioplasty. Afterwards, a stent is inserted to hold blood
vessel open

11. Endovascular Revascularization Therapy
• Axial imaging (computed tomography
(CT),magnetic resonance imaging (MRI)) is
used to quantify core infarct size and
hemorrhage.
• CT or MR angiography (CTA,MRA) can
determine large vessel patency, whereas CT
and MRI perfusion imaging can characterize
potentially salvageable tissue in ischemic
penumbra.

12. National Institutes of Health Stroke Scale

14. Intra-arterial Thrombolysis
• Intra-arterial thrombolysis is an option for
treatment of selected patients who can be
treated within 3-6 hours after the onset of
symptoms due to occlusion of the middle
cerebral artery and who are not otherwise
candidates for IV tPA

15. • Intra-arterial (IA) administration of
thrombolytics via a microcatheter positioned
in cerebral vasculature affords rapid local
delivery of greater therapeutic t/t
concentrations to vascular occlusion site

16. The Prolyse in Acute Cerebral Thromboembolism II
(PROACT II) trial demonstrated the effectiveness of IA prourokinase when given within
6 hours of acute stroke caused by middle cerebral artery occlusion. Patients were
randomized to IA recombinant prourokinase and IV heparin or heparin alone.

17. Mechanical Recanalization
• Narrow time windows and the risk of
hemorrhage associated with thrombolytic
agents prompted the design and application
of mechanical thrombectomy devices.
• Endovascular clot retrieval provides potential
for rapid flow restoration, with a decreased
incidence of clot fragmentation and distal
embolism

18. • The Multi Mechanical Embolus Retrieval in
Cerebral Ischemia (MERCI) trial used newer
generation Concentric retrieval device (L5).
Recanalization was demonstrated in 55% of
pts who did not receive tPA and in 68% of
those for whom tPA was given in a group of
pts with acute ischemic stroke presenting
within 8 hrs of onset of symptoms

20. MERCI clot retrieval device (left) and diagram demonstrating mechanism of action (right).
Spiral loops and suture material are designed to engage the clot and mechanically remove it
from the vessel

21. • The Penumbra System is an aspiration device
through which a thromboembolic clot can be
retrieved following acute stroke .
• The device removes thrombus via aspiration,
mechanical disruption, and extraction.
• Multiple aspiration catheters of varying
luminal diameters are available for use in the
cervical and intracranial vasculature,
depending on vessel caliber

22. Penumbra reperfusion catheters and separator wires of different sizes. Wire is
used to fragment clot as the catheter provides suction/aspiration

23. An anteroposterior view shows a Penumbra aspiration catheter positioned within the left middle
cerebral artery as indicated by the catheter tip (arrow) with Separator wire (A).
An artistic illustration depicts the process of clot removal with aspiration (B).
Angiogram images of a left middle cerebral artery occlusion before (C) and after
thromboaspiration (D) show complete vessel recanalization

24. Randomized Clinical Trials of Mechanical Thrombectomy for Acute Ischemic
Stroke

25. MR CLEAN, ESCAPE, EXTEND-IA, and SWIFT-PRIME Trials
• The multicenter randomized clinical trial of
endovascular treatment for acute ischemic
stroke in the Netherlands (MR CLEAN) study
was a randomized clinical trial in acute
ischemic stroke patients.
• The trial demonstrated an overwhelmingly
positive outcome in favor of intra-arterial
therapy over standard of care alone

26. mRS in MR CLEAN Trial comparing mRS 0–1, 0–2, and 0–3 between the groups showing significantly better
outcome with IAT than standard of care with OR of 2.06, 2.05, and 1.89, respectively.

27. • Endovascular Treatment for Small Core and
Proximal Occlusion Ischemic Stroke (ESCAPE) trial
was a randomized controlled trial comparing
rapid endovascular revascularization to standard
medical care including IV rtPA
• Extending Time for Thrombolysis in Emergency
Neurological Deficits–Intraarterial(EXTEND-IA)
was a randomized, controlled trial comparing
reperfusion with Solitaire FR device after IV rtPA
to patients receiving IV rtPA alone

28. A left internal carotid artery angiogram shows complete occlusion of the terminal segment which extends into the left
middle cerebralartery (A).
Fluoroscopy imaging shows a guide sheath positioned in the left internal carotid artery, a coaxially introduced
microcatheter extending into the internal carotid artery terminal segment, and a retrievable stent design thrombectomy
device (Solitaire FR) deployed within the left middle cerebral artery (B).
An artistic depiction of the device is shown in the inset. After mechanical clot removal, complete revascularization of the
left internal carotid artery and middle cerebral artery is observed on angiogram (C). The Solitaire FR is an example of a
retrievable stent design thrombectomy device (D).
Thrombus can be observed adherent to the device after thrombectomy (E).

29. • The Solitaire FR as Primary Treatment for
Acute Ischemic Stroke(SWIFT PRIME) trial was
a randomized, controlled trial comparing
stroke-related disability between combined IV
rtPA and Solitaire FR to IV rtPA alone in pts
within 6 hrs of symptom onset

30. Carotid Artery Disease
• Multicenter randomized clinical trials have
convincingly demonstrated that compared to
medical therapy alone, CEA and aspirin
therapy significantly reduce the incidence of
stroke and death in both symptomatic and
asymptomatic patients with severe carotid
stenosis

33. Carotid Artery Angioplasty and Stenting

34. Over-the-wire distal embolic protection device (EPD).
Filter is positioned in distal cervical internal carotid artery (beyond stenotic segment) to prevent
embolic debris from reaching intracranial circulation.

35. Lateral angiogram demonstrating critical proximal internal carotid artery stenosis (left). Embolic protection
device (EPD) is opened in distal cervical internal carotid artery (top of picture, middle). Following balloon
dilatation, stent is positioned across stenotic segment (middle). Lateral angiogram showing stent deployed in
distal common and proximal internal carotid artery, with minimal residual stenosis(right).

36. Patients at High Risk for Carotid Endarterectomy

37. Stenting and angioplasty with protection in patients
at high risk for endarterectomy(SAPPHIRE trial)

38. CaRESS: Carotid Revascularization Using
Endarterectomy or Stenting Systems
• Carotid stenting systems with distal embolic
protection (CAS) is equivalent to carotid
endarterectomy (CEA) in treatment of
symptomatic and asymptomatic carotid artery
disease in a broad-risk population.

39. • The French Endarterectomy versus Stenting in
Patients with Symptomatic Severe Carotid
Stenosis (EVA-3S) trial had inclusion criteria
similar to SPACE (symptomatic, >60% stenosis)
• Primary outcome included any stroke or death
at 30 days.

41. Intracranial Atherosclerotic Disease
• Intracranial atherosclerotic disease (ICAD) is a
common etiology of cerebrovascular disease,
responsible for at least 9% of all ischemic strokes
• The Warfarin-Aspirin Symptomatic Intracranial
Disease (WASID) trial and subset analyses
demonstrated that patients who had suffered an
ischemic cerebrovascular event and harbored
>70% stenosis of a referable intracranial artery
were at an exceptionally high risk for recurrent
stroke

43. Endovascular treatment of intracranial atherosclerotic
disease.
• Intracranial Angioplasty- Balloon angioplasty
• Intracranial Angioplasty and Stenting

44. The Wingspan stent is the first self-expanding system designed for intracranial
application .A hybrid of nickel and titanium (nitinol) metal construct allows navigation
of small and tortuous intracranial vessel
Gateway balloon and Wingspan stent (left). Stent deployment across an intracranial
stenotic lesion with resultant opening of vessel lumen (right).

45. In a patient with recurrent posterior circulation strokes, anteroposterior angiogram shows diffuse intracranial
atherosclerotic disease and severe narrowing of a right vertebral artery intracranial segment (arrow) resulting in 70%
stenosis and occlusion of the contralateral vertebral artery (A). A balloon mounted intracranial stent was implanted
(B). Angiogram following angioplasty and stenting shows no residual stenosis (C).

46. Clinical Trials
• The Stenting and Aggressive Medical
Management for Preventing Recurrent Stroke
in Intracranial Stenosis (SAMMPRIS) study

47. These results showed higher than expected risk of early stroke following PTAS and
lower than expected stroke with aggressive medical therapy alone

48. Vertebral Artery Disease
• Extracranial vertebral artery atherosclerotic
disease, including vertebral artery origin
stenosis, has been implicated as a common
cause of posterior circulation stroke (20% of
all posterior circulation strokes)

49. In this trial, 8 patients were randomized to medical therapy and 8 underwent
successful endovascular stenting, with no stroke or death occurring within 30
days in either group. Follow-up at a mean of 4.7 yrs revealed no vertebral
artery territory strokes in either gp and therefore no difference in outcomes

50. Anteroposterior projection angiogram of a right subclavian artery shows severe atherosclerotic stenosis of the right
vertebral artery origin (arrow, left). Attenuated contrast washout within the right vertebral artery (arrow, center)
illustrates severe hemodynamic compromise from the stenosis. Normal lumen caliber and antegrade flow is
restored after endovascular therapy with angioplasty and stenting (arrow, right).

51. HEMORRHAGIC STROKE
• Cerebral Aneurysms
• Ruptured Aneurysms
• Unruptured Aneurysms

53. • Endovascular coil embolization of ruptured
intracranial aneurysms when a pt has a good
clinical grade (World Federation of
Neurosurgical Societies grades I–III) and
aneurysm anatomy is suitable for
endovascular t/t is more likely than not to lead
to independent survival at 1 year than those
receiving neurosurgical t/t

54. Endovascular Treatment Modalities
• Coil Embolization-
• Improved detachment mechanisms, stretch-
resistant coils,3-D complex varying degrees of
softness, and coil lattice incorporating a
bioabsorbable polymer have been designed to
minimize procedural complications and help
prevent delayed recanalization.

55. Three-dimensional coil (left) and diagrammatic depiction of coil deployment through a
microcatheter positioned in an aneurysm (right).

56. Balloon Remodeling
• Balloon remodeling technique affords an
ability to effectively treat broad-neck
aneurysms by mechanically protecting parent
vessel from coil prolapse
• Positioned within parent artery, a small
balloon occlusion microcatheter is
intermittently inflated and deflated across
aneurysm neck

57. Diagram demonstrating balloon remodeling technique with HyperForm balloon (ev3 Inc.,
Irvine, CA) prior to coil placement.Balloon is positioned across neck of aneurysm to
temporarily prevent coil herniation into parent vessel

58. Lateral oblique projection angiogram shows a right internal carotid artery supraclinoid segment aneurysm in a
patient with subarachnoid hemorrhage (A). A balloon (arrow) inflated within the right internal carotid artery
across the aneurysm neck supports coil embolization (B). Complete occlusion of the aneurysm was
achieved(C). Pre- and post-treatment lateral projection angiograms show the treatment result (D, E).

59. Stent-Assisted Coil Embolization
• Balloon remodeling may not be sufficient to
prevent coil protrusion into the parent vessel.
• In such cases an endoluminal/endovascular
approach uses a permanently deployed
intracranial stent as supportive scaffolding.

60. Picture of a Neuroform stent with open-cell design (left) and diagrammatic depiction of stent-assisted coil
embolization through a microcatheter positioned in an aneurysm (right). Note that stent provides permanent
scaffolding for stabilization of coil mass

61. Three-dimensional reconstruction of a left superior hypophyseal region aneurysm (left). Measurements (right)
demonstrate cranialcaudad (1) and transverse (3) dimensions of aneurysm and size of the neck (2).

62. Large size of aneurysm neck compared to dome led to stent-assisted coiling technique being
employed. (A) Working projection oblique angiogram demonstrating stent tines positioned across neck of aneurysm.
(B) Arrows point to proximaland distal stent tines. (C) Unsubtracted view demonstrating stent position and coil mass.
(D) Postintervention angiogram in working projection showing no residual aneurysmal neck and no filling within coil
mass.

63. Alternative Treatments
• Liquid embolic agents may permit more efficient
aneurysmal dome and neck filling. Onyx LES (liquid
embolic system)
• Flow-diversion devices represents a potential paradigm
shift in t/t strategy for broad-neck aneurysms.
• Circumferential, endoluminal, parent-vessel
reconstruction allow for complete aneurysmal
occlusion in absence of direct endovascular
embolization.
• The Pipeline Embolization Device (PED (ev3 Inc.)) is
specifically engineered to reconstruct a segmentally
diseased vessel

64. A large right internal carotid artery aneurysm treated with a Pipeline embolization device at initial angiogram
(A), immediately after implant (B), and at 6-month follow-up (C), shows progressive and complete
obliteration of the aneurysm. A lateral view angiogram shows the aneurysm (D) with fluoroscopy imaging of
the device being deployed across the aneurysm neck (E). An artistic depiction of the device shows the low
porosity of the dense mesh device across the aneurysm neck (F).

65. (A) Anteroposterior (AP) angiogram demonstrating severe narrowing of M1 segment of left middle cerebral
artery and moderate stenosis of A1 segment of left anterior cerebral artery. (B) Hyperglide balloon positioned
across narrowed middle cerebral artery segment. Note two radiopaque markers that confirm position of
balloon. (C) Post-dilatation AP angiogram demonstrating an increase in caliber of proximal left middle
cerebral artery.

66. Management of Cerebral Vasospasm
• Occurring most frequently b/w 3 and 14 days
after aSAH, vasospasm causes a decrease in
blood flow and a resultant lowering of
cerebral perfusion pressure
• Oral nimodipine and hypertensive therapy to
enhance cerebral oxygenation in setting of
vasoconstriction.

67. • For vasospasm refractory to medical
management or in patients with treatment
contraindications, endovascular therapy has
emerged as an alternative or supplementary
therapeutic modality
• Both balloon angioplasty and IA vasodilator
infusion have established roles in mgt of
medically intractable vasospasm

68. • Balloon Angioplasty
• Intra-arterial Vasodilators-nimodipine

69. CEREBRAL ARTERIOVENOUS MALFORMATIONS
• A brain AVM is an aggregate of arterial and
venous communications with no intervening
capillary network
• Incidence of brain AVMs is 1.21 per 100,000
person years
• Mgt of cerebral AVMs relies upon
combination of 3 distinct therapeutic
modalities: endovascular embolization,
microneurosurgery,stereotactic radiosurgery

70. Anteroposterior (left) and lateral (right) angiograms before (upper) and after (lower) embolization of a 3-cm
arteriovenous malformation (AVM) at the inferior and middle left temporal gyri. AVM was supplied by two
inferior temporal branches of the posterior cerebral artery. Followingn-butyl cyanoacrylate (nBCA) embolization
to superior branch and Onyx-34 to inferior branch, there was approximately 25% reduction in total nidal
volume, with no opacification of a lateral perinidal aneurysm. This patient received radiotherapy after
embolization and in long-term follow-up had complete obliteration of the AVM.

71. Several agents have been used for AVM
embolization
• Polyvinyl Alcohol
• n-Butyl Cyanoacrylate
• Ethylene Vinyl Alcohol Copolymer
• Stereotactic Radiotherapy

72. CEREBRAL ARTERIOVENOUS FISTULAS
• Cranial Dural Arteriovenous Fistulas
• Cranial dural arteriovenous fistulas (DAVFs) are
direct shunts b/w arteries and venous sinuses or
cortical veins with no transitional capillary
network
• Mean age of presentation- 50-60 yrs
• Etiology-idiopathic,trauma, craniotomy or venous
thrombosis.
• These lesions account for 6% of supratentorial
and 35% of posterior fossa vascular
malformations

73. • C/F-proptosis, chemosis, ophthalmoplegia or ↑ed
ocular pressure
• Those with venous egress into transverse or
sigmoid sinus present with pulsatile tinnitus .
• Posterior fossa DAVFs cause lower cranial Nv.
deficits or brainstem findings
• Lesions draining into superior sagittal sinus can
manifest with nonspecific cortical symptoms such
as hydrocephalus, seizures, or mental status
change

74. • MRI reveal presence of a DAVF through flow
voids or edema secondary to venous
hypertension.
• Dilated vessels evident on CTA or MRA
• T/t -endovascular occlusion, surgical
disconnection,stereotactic radiosurgery
• Embolization, stereotactic radiosurgery is an
effective t/t modality used either alone or in
conjunction with endovascular therapy

77. Carotid-Cavernous Fistulas
• Abnormal arteriovenous communications in
cavernous sinus, represent a unique subset of
cranial arteriovenous fistulas

78. Grading Scale for Carotid Cavernous Fistulas

79. • Etiologies -pregnancy, sinusitis,trauma, and
cavernous sinus thrombosis
• C/F-Direct CCFs is sudden onset of
exophthalmos, conjunctival injection, and a
cephalic bruit.
• Associated cranial nerve palsies and visual decline
are common.
• Indirect CCFs have a more gradual onset and
mild presentation but may manifest in a similar
clinical fashion.

80. • Axial CT and MRI reveal proptosis, flow voids, an
enlarged cavernous sinus, or a prominent
superior ophthalmicvein.
• DSA is essential in classifying CCF and elucidating
precise fistulous site and pattern of venous
drainage.
• Injection of vertebral artery while manually
compressing i/l common carotid artery(in
presence of a post. communicating artery) aids in
localization, as reduced flow facilitates
visualization of fistula.

81. • Direct CCFs can be approached through
transarterial or transvenous access.
• The standard endovascular t/t of direct CCFs-
transarterial disconnection with a detachable
balloon.
• Current strategies employ use of detachable
coils, liquid embolic agents,and covered stents
via either a transarterial or transvenous
approach

82. A lateral projection right internal carotid artery angiogram shows a carotid cavernous fistula (arrow) (A). A
magnified lateral projection angiogram shows the fistula with indirect supply from inferolateral and
meningohypophyseal trunk arteries (arrows) in the early arterial phase (B),with rapid filling of the cavernous
sinus in mid-arterial phase (C), and venous outflow through the superior ophthalmic vein (arrow) (D).

83. A lateral projection right internal carotid artery angiogram shows the pre-treatment carotid cavernous fistula
(A). A transvenous approach was used by microcatheterization of the cavernous sinus via the facial and
superior ophthalmic veins (arrows), to achieve complete coil embolization of the fistula (B). Post-treatment
lateral projection angiogram shows obliteration of the fistula (C)

84. SPINAL VASCULAR MALFORMATIONS
• Progressive spinal cord symptoms with
considerable associated morbidity if
untreated.
• Occurs in males
• Dural AVFs frequently cause gradual ascending
paraparesis or bowel and bladder dysfunction,
whereas intramedullary spinal cord
malformations typically present with
hemorrhage.

85. • The arterial supply to spinal cord is derived from
a single anterior spinal artery (ASA) and paired
posterior spinal arteries (PSAs),segmental artery.
• ASA originates from both vertebral
arteries,proximal to vertebrobasilar junction
• Artery of lumbar enlargement or artery of
Adamkiewicz, provides main arterial supply to
spinal cord from lower thoracic region to conus
medullaris. It originates from a radicular vessel on
left, b/w T8-L4 levels

86. Frontal projection angiogram of the right T12 segmental artery (arrow) in early arterial phase shows
arteriovenous shunting from a spinal dural arteriovenous fistula (arrowhead) (A). Late arterial phase shows
further characterization of venous outflow (B). The unsubtracted angiogram image shows the relationship of
the vascular anatomy to the spinal column (C).

88. Perimedullary Arteriovenous Malformation
(Type IV)
• Vascular supply to these intradural
extramedullary fistulas is derived from either
the anterior (most commonly) or posterior
spinal arteries. They occur most frequently
b/w ages of 30 and 60 and often present with
progressive neurological deficits

89. Tumour Embolisation

90. Tumour embolisation
• Adjunct to microsurgical resection
• Tumors treated- meningiomas, glomus
tumors, juvenile nasopharyngeal
angiofibromas, hemangioblastomas,sarcomas,
head and neck squamous cell carcinomas, and
choroid plexus tumors

91. Embolization Procedure
• Diagnostic cerebral angiographic evaluation
prior to tumor embolization
• After proper positioning of microcatheter,
injection of embolic material is performed
under constant real-time digital subtraction
fluoroscopy. Distal tumoral penetration
prevents flow to the mass via collateral vessels
and results in devascularization and
subsequent tumor necrosis

92. Superselective right middle meningeal artery lateral oblique angiogram shows the left parasagittal meningioma
before (left) and after (right) embolization with polyvinyl alcohol particles. Nonvisualization of the tumor blush
after treatment is consistent with complete devascularization of the middle meningeal artery supply to the
tumor.

93. Anteroposterior (top row) and lateral (bottom row) right external carotid artery angiograms show a left
parasagittal meningioma withright middle meningeal artery supply. Characteristic features include a dural-
based location and a hypervascular appearance with a homogenously intense and prolonged vascular stain.

95. Vessel Selection
• Most agree that large external carotid artery
branches that directly supply a tumor mass and
are distant from dangerous anastomoses may be
treated
• Unless necessary, preoperative embolization of
pial blood supply is generally avoided as there is
increased pial supply subsequent to embolization
of external branches ; benefit of embolization is
usually outweighed by potential risk of ischemia

96. IDIOPATHIC INTRACRANIAL HYPERTENSION
• C/F-debilitating headaches and vision loss and
findings of papilledema and ↑ed CSF pressure
• Sxcal therapies for those pts who experience
progressive visual decline despite maximum medical
therapy include optic nerve sheath fenestration and
ventricular shunt placement.
• In selected patients with progressive visual threat
despite maximum medical therapy, and findings of a
substantial pressure gradient across a focal dural sinus
narrowing,endovascular stent implantation can be
considered to reduce risk of vision loss

97. Causes of IIH

98. Anteroposterior and lateral projection images show microcatheterization
(arrows) of the superior sagittal sinus for venous pressure manometry (top row).
Anteroposterior and lateral projection venograms show bilateral transverse sinus narrowing
before treatment (arrow, middle row) and improved lumen caliber and antegrade flow following
right transverse sinus stenting (arrow, bottom row). Mean venous pressures improved from 51
mm Hg to 17 mm Hg within the superior sagittal sinus following treatment

101. References
• Bradley’s Neurology in Clinical Practice 7th
Edition.