7. CIRCLE OF WILLIS
• Grand Vascular Station of the
Brain
• Classical –18% to 20%
COMPONENTS
• Internal carotid arteries
• Horizontal segments of Anterior
cerebrals(A1)
• Anterior communicating artery
• Proximal segments of posterior
cerebrals(P1)
• Posterior communicating
arteries
• Basilar artery
8. Anterior cerebral artery (ACA)
The ACA is divided into five segments
A1 segment is located between the
ICA bifurcation and the ACoA.
A2 segment extends from the ACoA
to the region between the rostrum and
the genu of the corpus callosum
(GCC)
A3 segment curves around the GCC
and ends at the rostral part of the body
of the corpus callosum.
A4 and A5 segments follow the
superior surface of the corpus
callosum with a virtual plane of division
at the level of the coronary suture.
9. Branches of ACA
• A1- medial lenticulostriate artery
• ACoA- Perforating branches
• A2- Recurrent artery of Heubner (RAH)
Orbitofrontal artery
Frontopolar artery
• A3- Pericallosal and Callosomarginal a.
• A4 & A5- Cortical branches
11. MIDDLE CEREBRAL ARTERY
• Larger terminal branch of ICA
• Run laterally in stem of lateral sulcus
• Curves on superolateral surface &
• Runs backwards in depth of posterior
ramus of lateral sulcus
• M1 segment =horizontal segment from origin to
its bifurcation (it is in sylvian fissure)
• M2 segment =lacunar segment -in the
insula loops over insula—laterally to exit
from sylvian fissure
• M3 segment = opercular branch-from
sylvian fissure & ramify over cerebral cortex
• Anomalies of MCA are uncommon
18. BASILAR ARTERY
• Right and left VA unite to
form basilar artery
• Courses infront of pons
(Prepontine cistern) &
terminates in the
interpeduncular cistern
• 3cm in length,1.5 to 4mm in
width
• >4.5mm width-abnormal
19. Normal VARIANTS
1. Fenestrations and duplications,
2. Variants of the circle of Willis,
3. Persistent carotid-basilar anastomoses
4. Anomalies identified in the skull base.
19
20. Fenestration of the anterior communicating
Duplication of the anterior communicating
Artery each vessel originating separately
artery
from an anterior cerebral artery.
Fenestrations
of the anterior cerebral
artery
20
21. Normal Variants of the Circle of Willis
Azygos anterior cerebral artery Trifurcation of the anterior cerebral artery
Hypoplasia of an A1 segment of the anterior
cerebral artery
Bihemispheric anterior cerebral artery
Absence of an A1 segment of the anterior cerebral 21
artery
22. Accessory
middle
cerebral artery
Absence of the anterior communicating artery
Bilateral fetal
posterior cerebral
arteries
Early bifurcation of the middle cerebral artery.
CT angiogram shows a posterior
communicatingartery (arrowhead) that arises
from the apex of a funnel-shaped infundibulum
(arrow)
22
23. Persistent Carotid-Basilar Artery Anastomoses
Persistent Trigeminal CT angiogram depicts a hypoglossal artery
(arrowhead) that arises from the proximal
Artery internal carotid artery (arrow)
23
24. Normal Variant Arteries in the Skull Base
1. Persistent stapedial artery,
2. Aberrant internal carotid artery
3. Hypoplasia or agenesis of the
internal carotid artery.
24
32. Cerebral veins
• Superficial cortical veins
• Near vertex they cross Subdural Space to enter SSS
• Most are unnamed
Superficial Middle cerebral vein( along sylvian
fissure)
Vein of Trolard
Vein of Labbe
• Deep cerebral veins
Vein of Galen
Basal veins of Rosenthal
Subependymal / Medullary veins
33. BLOOD SUPPLY TO RELEVENT PARTS OF BRAIN
• In general-cortical branches of 3 cerebral art
• Motor area-frontal cortical branch of MCA; Precentral
area and paracentral lobule-anterior cerebral artery
• Auditory area-temporal cortical branch. Of MCA
• VISUAL AREA-occipital cortical branches of PCA
• Speech area –cortical branches of MCA
33
35. Conventional angiography
• It is gold standard because of the outstanding resolution
and anatomical nature of the information
• Main disadvantage is it is a invasive procedure and is
associated with complications
35
38. Digital subtraction angiography
• DSA have arisen as a result
of digital data
acquisition, storage and
processing.
• The technique uses lower
doses of contrast medium
because of superior contrast
resolution.
• Fluoroscopy technique used
in interventional radiology to
clearly visualize blood
vessels in bony or dense
soft tissue environment
38
39. Digital Subtraction Angiography
(DSA)
• Images produced using
contrast medium by
subtracting 'pre-contrast
image' from later images with
contrast
• Vessels are subtracted ―live‖ –
instantly see non-bony
superimposed images
• The major disadvantage of
DSA is reduced spatial
resolution.
39
41. ULTRASONOGRAPHY
• EQUIPMENT :
• High resolution linear array transducer
• Used in cases of infants for evaluation of the
brain parenchyma
• Windows :
• Anterior fontanelle
• Posterior fontanelle
• Mastoid
41
43. CT ANGIOGRAPHY
CT Angiography provides a
comprehensive analysis of the
vascular anatomy including the
location, size, and length of the
arteries and veins.
CT Angiography is used to detect;
• Dissections
• Aneurysms
• Plaque
• Stenosis Optimal image quality depends on two
factors:
• Morphological layout and
CT angiography technique (scan
aberrations protocol, contrast
• Pre and Post surgical assessments material injection protocol, image
reconstruction
methods) and data visualization
technique(image postprocessing). 43
44. ADVANTAGES ARTEFACTS
• The more slices that can be • Motion artifacts reduced by
acquired per rotation faster scanning
• The longer the volume that can
be scanned
• The higher the resolution • Stair-step artifacts in 3D
possible reconstructions reduced by
• The better the reproduction of using thinner slices
2D and 3D reconstructions
• The greater the detail available • Partial volume artifacts
in all 3 axis (x,y and z)
reduced by using thinner slices
• Patient comfort
• Non invasive investigation
• Easily available to all levels of
socioeconomic status
45. POST PROCESSING
• Coronal and Sagittal MPR (multi planar
reconstructions)
• Shaded surface display, or surface
rendering, is an algorithm that provides a
good 3D impression ofthe surface of an
object.
3D volumetric images with rotational
images comprising of bone and non bone
backgrounds.
• MIP (Maximum intensity projections)
• Measurements
45
46. MR ANGIOGRAPHY
constitutes group of MR imaging techniques that can be used to directly image
flow in arteries, veins, and cerebrospinal fluid.
Time-of-flight imaging is susceptible to saturation effects, and short Ti
substances may simulate flow.
•Two-dimensional time-of-flight imaging is useful in cranial venography in
assessing the patency of the dural sinuses or venous drainage from an
arteriovenous malformation.
•Three-dimensional time-of-flight images depict small and medium-sized
aneurysms.
Phase-contrast imaging has excellent background suppression, allows
variable velocity encoding, and provides directional flow information.
•Two-dimensional phase-contrast imaging is useful in the assessment of the
patency of major vascular structures.
•Three-dimensional phase contrast imaging (with 30-cm/sec velocity
encoding) is also useful in depicting small and medium-sized aneurysms
•Cine Phase contrast imaging – hemodynamic flow information. Allow imaging
of csf, venous and arterial flow.
46
49. INTRODUCTION:
• Interventional and Endovascular Neurology is the Neurological
subspecialty focused on endovascular and other minimally invasive
approaches to the diagnosis and management of vascular and non-
vascular neurological diseases.
• The section is committed to advancing all diagnostic and therapeutic
interventional procedures that involve the neurological patient
community and to support education and research initiatives that will
expand this field.
• Endovascular therapies include
1. Embolotherapy
2. Cerebral revascularization
Non vascular aspects of interventional neuroradiology include pain
management, percutaneous biopsies and vertebroplasty.
50. • Cath lab.-known as ―operating room‖ or ―special
procedures room‖.
• Radiographic Imaging Equipments
• Biplane angiography with digital subtraction
ability, high resolution image intensifier is
recommended. Digital Road map fluoroscopy
capability is mandatory, preferably with simultaneous
live unsubtracted imaging . Now a days 3D CT is used
too.
• Critical care of patients undergoing endovascular and
interventional procedures.
51. VASCULAR INTERVENTION:
• Embolotherapy continues to evolve in its active
consideration in the preoperative management of
aneurysms, vascular malformations and vascular tumors.
• This progressive increase in demand has been principally
as a result of development of newer microcatheter
delivery systems and of safer and more varied embolic
agents.
• more target specific embolization with a greater degree of
preservation of adjacent normal vascular anatomy.
• These include particulate emboli, coils, balloons, tissue
adhesives, non adhesive agents, sclerosing agents and
chemotherapeutic agents.
52. Classification:
Embolic agents
I. Particulate embolic agents( agent of choice).
Absorbable Non Absorbable
II. Mechanical embolic agents
III. Liquid embolic agents.
Absorbable agent:Gelfoam( Powder /sheet), Avitene
Use: topical thrombotic agent in conventional surgery.
to "protect" normal vessels.
Non absorbable: PVA(150 to 1000 microns), particles
(Ivalon, Biodyne, Contour Emboli).
• PVA: small( embolization of vascular tumors) and large
size( occlusion of larger, high flow vascular malformations).
MOA—Adhere to vessel wall(lumen occluded),necrotising
vaculitis.
Temporary effect—Weeks to Month
53. • Recently, a newer class of microembolic agent has been
introduced
• Soft, smooth surfaced, deformable particles ( Embospheres
(Microsphere) and Bead Block (Terumo))
• tend to ovalize when confined, a trait that makes these
agents more effective in more distal embolotherapy.
• ADV: do not adhere to vessel walls as do crystalline PVA
particles, particles are more likely to reach the capillary bed
of the tumor.
Bead Block
54. COILS :
Guglielmi detachable micro coil. (GDC)
• Platinum micro coils soldered on stainless steel micro
wires. once in desired position detached by passing Direct
current which causes electrolysis at the soldered site.
• can be positioned, withdrawn and repositioned repeatedly
until the desired position is obtained.
Advantage: Coil can be withdrawn before final placement.
The Hydrocoil (Microvention) is unique in that it is coated with
a hydrogel that expands after deployment.
55. BALLOONS
• Latex and silastic balloons
• Advantages:
1) the ability to occlude a vessel at a precise location
2) the ability to flow navigate attached, partially inflated
balloons to distal locations along a tortuous course
3) the ability to rapidly occlude vessels larger than the
caliber of the catheter
4) the ability to inflate, deflate and reposition repeatedly until
the desired position is achieved.
56. LIQUID EMBOLIC AGENTS
• n-butyl cyanoacrylate (NBCA)
• Histoacryl
• This agent will rapidly polymerize on contact with any ionic
substance such as blood, saline, ionic contrast media and
vessel epithelium.
• ADV:rapidly occlude high flow arteriovenous malformations
with a more permanent result
• DISADV:The catheter must be rapidly withdrawn after each
injection of NBCA, resulting in frequent, time consuming
catheter exchanges
• Onyx: non adhesive liquid embolic agent safer and
effective than NBCA
57. SCLEROSING AGENTS
• Absolute ethanol
• Sotradecol (sodium tetradecyl sulfate) behaves similarly to
alcohol, but with less associated pain.
• Hypertonic saline and glucose solutions are also effective
sclerosing agents that work rapidly in both the arterial and
venous systems.
• The results of embolotherapy with ethanol when compared
to the particulate agents and NBCA have shown a more
permanent occlusion of abnormal vessels without the
inherent risks associated with tissue adhesives.
58. CEREBRAL REVASCULARIZATION…..
• Intra-arterial cerebral revascularization incorporates several
new technologies and newer applications of techniques that
have been well established in peripheral revascularization.
The focus on acute stroke reversal offers an exciting new
aspect to interventional neuroradiology.
59. Vascular Interventional procedure of brain
Endovascular procedures.
Direct percutaneous procedures.
Endovascular procedures:
1. Endovascular technique for lumen restoration.
2. Endovascular technique for lumen obliteration.
3. Endovascular treatment of A V shunts.
4. Endovascular treatment for vein of galen aneurysal malformation.
5. Endovascular treatment of dural arteriovenous shunts.
6. Brain tumour embolisation and chemotherapy.
7. epistaxis endovascular therapy: Embolization of refractory head and
neck bleeds.
8. WADA and functional testing.
9. petrosal venous sinus sampling for Cushing disease
10. pseudotumor cerebri endovascular therapy with venous sinus stenting
11. endovascular repair of traumatic head and neck vascular injuries
60. Direct percutaneus procedures:
(1) Image guided Embolisation of tumour.
(2) Image guided embolisation of AVM.
(3) Image guided photodynamic therapy.
61. Hyperacute ischemic stroke
1)Intra-arterial thrombolysis :
It involves the direct infusion of thrombolytic agents into
the occluding thrombus .
Higher local concentration of drug.
• Lower systemic concentration.
• Fewer extracranial haemorrhagic complications.
• Faster and more complete recanalisation .
• This allows a longer time window of 3–6 hours or longer if
perfusion studies are favourable.
63. 2) Mechanical procedures
1)Microguidewire applied
to disrupt the clot
facilitate the action of
the thrombolytic agent.
2) Clot retrieval devices
or Snare which may
actually extract the
thrombus from the
occluded
artery, achieving
reperfusion much
more readily.
64. Recent mechanical thromolitics
The BONnet consists of a self-expanding nitinol
braiding with polyamide filaments passing
through the interior to enlarge the surface area
and enable better fixation of the thrombus mass.
The system can be either put distal to the
thrombus or released into the thrombus. B, The
CRC is based on a fiber work of polyamide
filaments whose lengths fromproximal to distal
end increase. The CRC has an additional nitinol
thread cage at the proximal end of its fiber brush.
This nitinol cage gives it a higher radial range. C,
ThePhenox pCR is based on perpendicularly
oriented polyamide microfilaments that create an
attenuated palisade.
The Penumbra System is based on an
aspiration platform that includes reperfusion
microcatheters connected to an aspiration
pump. A teardrop-shaped separator is
advanced and retracted within the lumen of
the reperfusion catheter to debulk the clot
for ease of aspiration.
65. .
3) Balloon Angioplasty or
stent placement
If thrombus is
superimposed upon a
stenosis. (Atherosclerotic
plaque).
Solitaire FR stent (ev3). A self-expanding stent that can be fully
deployed and then completely retrieved
67. • A. Left Vertebral Artery Injection demonstrating extensive
clot in the basilar artery .
• B. Following Urokinase via a microcatheter there is
complete resumption of normal flow.
68. TREATMENT OF CEREBRAL VASOSPASM
Cerebral vasospasm represents a significant cause of
morbidity and mortality in patient with subarachnoid
haemorrhage leading to ischemic deficits.
Medical treatment(Triple H )
Hypertension
Hypervolemia
Haemodilution
Endovascular treatment:
(1)Pharmacological relaxation of spastic vessel by Selective
intra-arterial papavarine infusion.
(2) Mechanical dilatation of spastic segment (balloon
dilatation).
70. Angioplasty and stenting of extracranial and
intracranial vessels.
Indications
• Carotid stenosis(>70%)
• Vertebro basilar artery stenosis.
• MCA stenosis(>50%)
Purpose:
Reduce incidence of recurrent stroke (TIA).
71. Percutaneous transluminal angioplasty(PTA)
Pre treated with antiplatelet
agents.
Under LA via femoral artery.
The patient is systemically
heparinised and the carotid artery
catheterised, a guide wire crosses
the stenosis, a protection device
is deployed . Balloon inflation (8
atmospheric pressure for 10 sec)
deflated if significant stenosis
persists repeat procedure for 2
to 3 times.
Clopidogrel and aspirin are
maintained for three months.
72. Stenting
• Method of choice
• Under LA
• Pre operative antiplatelet therapy(Aspirin and
clopidogrel)
• Following pre operative angiography ,a
guiding catheter(6Fr) is placed to common
carotid artery the stenosis is crossed with a
soft tip guidewire,a protection device is
deployed .The stenosis is predilated using an
angioplasty balloon, and a stent is deployed
across the stenosis and redilated.
73.
74. pathophysiological process of
carotid artery dissection
proceeding from the acute
stage to either spontaneous
healing (1), formation of false
lumen (2), residual stenosis
of varying degree or complete
occlusion (3), and formation of
a pseudoaneurysm (4). A stent
is used in cases not
responding to medical therapy
either to relieve a
hemodynamically significant
stenosis, to occlude a false
lumen, or to serve as a
scaffold to enable coil
embolization of a wide-necked
pseudoaneurysm.
75. Carotid Cavernous sinus fistula
Carotid cavernous fistulas (CCFs) result
from spontaneous or acquired ,
abnormal connection(s) between the
cavernous ICA and venous channels
of the cavernous sinus, and are either
high or low flow. Barrow’’s Classification (1985)
trauma
Treatment modalities:
Type A—High flow type
Detachable balloons is the
treatment of choice for most type A
CCFs .The currently available latex
balloon is deployed up the ICA,
through the defect and inflated within
the cavernous sinus, occluding the
fistula and preserving the ICA.
77. Transcatheter coil embolisation-
Routes –Trans venous (Preferred)—Femoral vein—inferior
petrosal sinus cavernous sinus-Platinum micro coils with
attached dacron fibres is used.
Trans arterial route---GDC coils are used to reduce the
risk of recoiling in the ICA.
78. Liquid embolic agents
Onyx can be deployed through the micro catheter
via venous route into the cavernous sinus, with
balloon protection (non-detachable) in the ICA .
Type B—Low flow Carotid cavernous sinus fistula
Polyvinyl alcohal (PVA)---150—250 micron Size .
selective embolisation of external carotid artery feeders
is done.
If Recanalisation,, occur, transvenous coil occlusion of
the cavernous sinus either through the jugular vein and
inferior petrosal sinus or through the superior ophthalmic
vein achieves cure in most patients.
Carotid compression maneuver
Facilated thrombus formation.
79. Endovascular treatment of intracranial aneurysms
An aneurysm is a sac filled with
blood which is in direct
communication with the lumen
of an artery.
True AneurysmLocal dilatation
of the artery.
False aneurysm Sac with walls
formed of condensed
perivascular connective tissue
which communicate with the
Common site of intracranial Aneurysm
artery through an aperture in its
wall.
80. • Clip vs Coil
What to choose ?
• • This decision needs to be made with
knowledge of:
‐‐‐ the safety and efficacy data
‐‐‐the patient’s expected longevity
‐‐‐aneurysm factors – size
‐‐ configuration
‐‐ location
• ‐‐‐the operator’s experience.
• Equally important to consider whether the aneurysm
• ‐‐‐unruptured
• ‐‐‐ruptured
• This complex decision requires entertaining all the variables, ensuring
that patients receive the most appropriate care .
81.
82.
83. Coil embolisation:
Through trans-arterial
route a micro catheter
is placed in the lumen
of the aneurysm-
through the micro
catheter ,soft platinium
coils are packed in the
aneurysm.
84. Large ruptured aneurysm, pre embolization (A), and post embolization with GDC coils ( B&C).
Assisted aneurysm coiling techniques, including balloon assist (A) (Hyperform balloon catheter, MTI) and
84
Neuroform stent assisted technique (B,C) ( Target Therapeutics Corp / Boston Scientific )
85. Newer technique to reduce coil compaction and
recanalisation
• Coils with more complex shapes.
• Bioactive coils (coated with polyglycolic polylactic acid).
• Hydrogel coils.
• Radioactive coils (incorporated with P32 emitting ß
radiation).
86. • When patency of the
parent vessel cannot
be assured (Fusiform
or serpentine ,wide-
necked aneurysm,false
aneurysm)-Vessel
may be permanently
occluded by balloon or
coil embolisation with
prior test occlusion.
.
87. Giant Aneurysm
Size more than 2.5cm.
• Giant aneurysms are often sub-optimally treated using coils
alone.
• The accepted treatment ----parent vessel occlusion.
• Trial balloon occlusion (TBO) .
• When parent vessel occlusion cannot be tolerated.
Surgical bypass procedures.
Embolisation (high density onyx).
stent .
88. Parent vessel (left ICA) occlusion in the management of a
giant cavernous carotid aneurysm.
89. Endovascular treatment of cerebral AVM
Arteriovenous malformation (AVMs) are a complex
conglomerate of abnormal arteries and veins. They lack
an intervening capillary bed and there is resultant high
flow arteriovenous shunting through one or more
fistulae.
Therapeutic options
1) Neurosurgery
2) Embolisation
3) Stereotactic radiosurgery.
Aim of treatment
1)Obliterate the AVM completely .
2)Eliminate the risk of haemorrhage.
3)Reduce the effects of steal or venous
congestion .
90. Spetzler Martin grading system (Grade 1 to 5)
Reflects the degree of surgical difficulty and risk of surgical
morbidity and mortality, and the scale is based upon AVM
size, venous drainage, and location .
AVM Size---
Small ---- 0 to 3 cm - 1 point.
Medium --3 to 6 cm - 2 points.
Large ----- > 6 cm - 3 points.
AVM location---
Non-eloquent region -- 0 point.
Eloquent region --------1 point.
Pattern of venous drainage---
Superficial ----------0 point.
Deep -----------------1 point.
91. Treatment rationale:
Grades 1 and 2 and some grade 3 ---surgery recommended.
Grade 3 AVMs with deep inaccessible feeders, surgery with
embolisation or stereotactic radiosurgery is considered .
Grade 4 and 5 AVMs is usually multidisciplinary
Embolisation
under general anaesthesia.
Superselective catheterisation of the feeding
arteries using a microcatheter with or without the aid
of a micro guidewire.
Liquid embolic agents are generally used, either
onyx or n-butyl Cyano acrylate (NBCA).
other embolic agents like balloon,Liquid coil can be
used.
94. A middle aged patient
presenting with an AVM
near the visual area of the
left hemisphere which
hemorrhaged once.
Presurgical embolisation Before Treatment
was conducted to reduce
the size of the AVM. Pre-
embolisation image A
versus post embolisation B
shows the substantial
reduction in size. She had
an excellent outcome from
surgery. Following Embolisation in
preparation for surgery
95. Dural AV fistula
Dural arteriovenous fistulas (DAVFs) abnormal
arteriovenous connections within the dura, usually within the
walls of a dural sinus .
• They are acquired lesions idiopathic most common venous
sinus thrombosis and/or venous hypertension.
• Thrombosis triggers the stimulation of angiogenesis and
engorgement of microscopic arteriovenous channels that
normally exist in the dura.
• The cavernous sinus, transverse and sigmoid sinuses are
most often implicated, but any sinus may be involved ..
• Premature visualization of intracranial veins orvenous sinuses
during arterial phase-Characteristic
96. Cognard’s classification
• Type I includes DAVFs which drain into a
sinus with normal antegrade flow.
• Type II DAVFs --insufficient antegrade flow
with reflux into either venous sinuses
(IIa), cortical veins (IIb), or both (IIa+b).
• Type III fistulas drain into cortical veins without
venous distension.
• Type IV drain into cortical veins with venous
ectasia.
• Type V drain into spinal perimedullary veins.
97. Management
• Type I fistulas --carotid or occipital artery compression
, arterial embolisation using PVA particles
Type IIa treatment of choice is arterial embolisation of
ECA feeders using PVA particles
• types IIb and IIa+b --Transvenous coil occlusion of the
involved dural sinus.
• Types III and IV---endovascular occlusion of the
draining cortical vein itself using coils may occlude the
fistula preserving dural sinuses.
99. Vein of galen Aneurysmal malformation
types—
1)Direct AVM--Choroidal
arteries/Thalomoperfora
te actually communicate
with the vein of galen.
2)Indirect ---AVM in the
thalamus or mid brain
veins drain into the vein
of galen.
100. Intervention
If possible intervention deferred to allow growth of the
child, as intervention in neonate is difficult and
hazardous .
Criteria for neonatal or infantile intervention:
Cardiac failure unresponsive to medical therapy.
Progressive macrocephaly.
Seizures.
Developmental delay.
Reversible neurological deficit.
• AIM— TO REDUCE THE AMOUNT OF AV SHUNT.
• Arterial approach ---Permanent embolic agent---
NBCA glue, Onyx.
• Transvenous route tried.
102. CEREBRAL VENOUS SINUS THROMBOSIS
Intravenous anticoagulation — most
cases are successful
Local thrombolysis
INDICATIONS:
Presentation in coma.
Clinical deterioration despite full anticoagulation.
Treatment modalities
1) Pharmacological thrombolysis of the cerebral
venous sinuses is usually performed via the
Transvenous femoral route in an anaesthetised
patient.
103. 2)Pharmaco-mechanical thrombolysis may also be
achieved using a microcatheter,microwire or
microsnare.
Local pharmacomechanical thrombolysis in
superior sagittal sinus (SSS) thrombosis.
104. .
3)Mechanical—
Saline jet vacuum device
--
It consists of a double
lumen 5 French catheter
tapering to 3.5
French, high velocity
saline jets, exiting the
catheter at a pressure of
2500 psi, are directed
through one
lumen, connected to a bag
of heparinised saline. A
venturi effect breaks up
the thrombus and the Saline jet vacuum device
debris is directed down the
other lumen and collected
in a bag.
105. Examples of mechanical measures to remove clot. A,
low pressure angioplasty, B clot disruption with the
Neurojet (Possis) and c. clot retrieval with the Merci
device.
105
107. IDIOPATHIC INTRACRANIAL HYPERTENSION
• remains a diagnosis of exclusion
( Friedman D., Jacobson D.: Neurology 59, 2002)
• To clarify the relation of IIH to associate narrowing of
lateral dural sinuses
• The neuro interventional community is still debating and
strives to justify neurovascular strategies for treatment.
--Causes
• Focal narrowing in the transverse sinuses unilateral or
bilaterally.
• Secondary to raised central venous pressure .
108. IDIOPATHIC INTRACRANIAL HYPERTENSION
• Investigation :MRI, MRV
• Catheter angiography with retrograde venography
• Pull-back manometry
• Focus of interest of venous manometry:
a) gradients across the irregularities of lateral sinus
b) gradients at confluence of sinuses/jugular bulb
Intervention---Stenting
• General anaesthesia is required for stent deployment
because the dura and sinuses are sensitive to pain.
Stenting is achieved directly through a percutaneous
jugular venous puncture. A guide catheter is manipulated
into the transverse sinus and a self expanding stent
deployed across the stenosis .
109. Optic papilla protrusion
Endovasal manometry: lft
Compliant balloon angioplasty of lateral sinus
Follow up 6 we Gd MRI
Initial Gd MRI
111. SKULL BASE TUMOURS
Common tumours requiring preopreative
embolisation are
• Meningiomas.
• Angiofibromas.
• Glomus tumours .
Objective
selective obliteration of arterial feeder before surgical
resection.
• Delivered under sedation by trans femoral route by selective
catheterisation of the vascular pedicle.
• Aim to occlude the pre capillary arteriole.
112. • Embolic agent —PVA(150-250 microns).
If intra tumoural shunts are present --
Particle size increase.
Slurry of PVA and AVitene.
Small coil or silk sutures.
Liquid coils.
Embolisation should be performed 24–72 hours before surgery
to allow progressive thrombosis.
• If very small size particle are used then skin necrosis and
cranial nerve palsy occur.
117. Brain tumour chemotherapy
Principle→Intra arterial infusion of chemotherapeutic
agents
↓
1)increased concentration of c.t.agents
locally
↓
2)increase cytotoxicity, Decreased side
effects.
Procedure:
Selective catheterization of the artery supplying the tumour done
under systemic heparinisationc.t. agents infused.
118. Chemoembolization
Chemoembolization works to attack the tumour in two
ways.
1) Delivers a very high concentration of chemotherapy
directly into the tumor, without exposing the entire body
to the effects of those drugs.
2) The procedure cuts off blood supply to the tumor,
depriving it of oxygen and nutrients, and trapping the
drugs at the tumor site to enable them to be more
effective.
• Super selective catherisation of the vascular pedicle is
done.
• Chemotherapeutic agents mixed with particulate
embolic agents infused through the micro catheter.
120. Direct percutaneous embolisation in vascular
malformation of head and neck
Low flow malformation like haemangio-
lymphangioma or venous malformation.
Under image guidance needle is placed
percutaneously in the lesion
↓
Contrast injected through the needle to delineate the
vascular compartment and venous drainage
↓
Concentrated alcohol injected to the lesion.
121. Image guided photodynamic therapy
Photodynamic therapy is a minimally invasive palliative treatment
for malignancy .
Intra venous injection of photosensitizing drugs.
Image guided needles placed in the tumour
Fibre optic cables are placed through the needles,providing a
foccused delivery of laser light.
Laser light + Photosensitising drugs Activates the drug
Singlet oxygen(highly cytotoxic) Interacts with
Oxygen
122. CONCLUSION
• Proper knowledge of vascular anatomy is very important .
Proper pre surgical ,clinical and radiological assessment helps
in surgical planning and avoid catastrophy.
• There has been enormous growth and development in neuro
endovascular expertise and technology in recent years, and
this expansion continues allowing increasingly safe and more
effective ways to treat many intracranial and extra cranial
vascular lesions .
• It is necessary to provide the patient with all treatment options.
Considering cost-effectiveness and that endovascular
treatment has lower morbidity and mortality rates than does
neurosurgery. It is crucial for the group to take a leading role in
the future of neurointervention.
123. OLD NEWER
Recent principle
In medical science
Minimum Access -
Maximum Result
Notes de l'éditeur
ICALarger branch of CCAAt C3 level
Not truly a circle but an arterial polygonBest potential collateral flow in occlusive vascular disease
A1 in lamina terminalis , A2 starts in lamina terminalis and then in interhemispheric fissure
The cortical branches of the A4 and the A5 usually supply the posterior third of the superior frontal gyrus, part of the cingulate gyrus, a portion of the premotor, motor, and somatic sensory areas.
Knowledge of the presence and clinical relevance of normal variants such as fenestrations, duplications,and persistent fetal arteries plays a crucial role in the diagnosisand management of acute stroke and subarachnoid hemorrhage and may aid in surgical planning.
A duplication is defined as two distinct arteries with separate origins and no distal arterial convergence (3) (Fig 1). Fenestration, by contrast, is defined as a division of the arterial lumen into distinctly separate channels, each with its own endothelial and muscularis layers, while the adventitia may be shared (
It may be difficult to differentiate an accessory middle cerebral artery from a duplicated middle cerebral artery. A smaller middle cerebralartery branch arising from the anterior cerebral artery is designated as an accessory middle cerebral artery, whereas a smaller middle cerebral artery branch arising from the distalcarotid artery is called a duplicated middle cerebral artery
The persistent trigeminal artery is the most common and most cephalic of the persistent carotid vertebrobasilar anastomoses Two types of persistent trigeminal artery havebeen described—lateral and medial. A persistent trigeminal artery also is classified according to the configuration of the ipsilateral posterior cerebral artery: In the presence a Saltzmantype 1 persistent trigeminal artery,the posterior communicating artery is absent and the persistent trigeminal artery supplies the entire vertebrobasilar system distal to the site of anastomosis. In the presence of a Saltzmantype 2 persistent trigeminal artery there is a fetalposterior cerebral artery, and the ipsilateral P1segment is absent (
Normal arterial variants that may be identified within the skull base include persistent stapedialartery, aberrant internal carotid artery, and hypoplasia or agenesis of the internal carotid artery.
Basal v of Rosenthal -form in sylvianfiss—amb cist—v of GalenGreat v of Galen=short(1-2cm) single midline origin under splenium of corpus callosum—curve posteriorly & towards straight sinusMajor anastomotic veins According to DiChiro, the vein of Labbé predominates in the dominant hemisphere nearly twice as often as it predominates in the non dominanthemisphere, andthe vein of Trolard predominates in the non dominanthemisphere with approximately the same frequencyThe deep veins are divided into a ventricular group, composed of the veins draining the walls of the lateral ventricles, andacisternal group, which includes the veins draining the walls of the basal cisterns.
Latex balloons are more distensible and compliant than silastic balloons, and therefore more readily conform to the shape of a vessel reducing the risk of vessel rupture. Latex also has afar greater coefficient of surface friction than silastic balloons. large high flow vessels as in trapping procedures and in the treatment of carotid-cavernous sinus fistulae.
Risks associated with the use of ethanol include peritumoral swelling, pain and necrosis of normal peritumoral tissue via normal microscopic anastomotic branches.
Discussion in later slides
Streptokinase allergy
Snare is cork screww like intraarterial device ( flexiblkenetinol , nickel and titaniumThe device consists of the Merci retriever, the Merci balloon guide catheter,and the Mercimicrocatheter (Concentric Medical). . Can be useed 8 hr …recent Merci retriever system Concentric Medical) and the Catch system (a tiny wire basket that retrieves thethrombus. Both devices work at the distal end of the clot. Two mechanical recanalization devices evolvedduring the last year. …now a days These are the Phenox Clot Retriever (Phenox, Bochum, Germany) and the Penumbra System(Penumbra)fda 2008.
the Phenox Clot Retriever was able to filter micro- and macrofragments that wereformed during penetration and retrieval.
Carotid stenting with and without embolic protection devices continues to improve with newer designs.
Carotid endarterectomy in greater than 70%stenosis.
Principle ECA feeders are :1-Int. maxillary artery –distal branches2-MMA –meningealbranch3-Accessory meningealartery –meningealbranch4-Ascending pharyngeal artery-meningealbranchICA feeders –Duralbranches from cavernous segment-C5 branches and the inferolateraltrunk
Spetzler Martin Grading system (Drawbacks)Definition of eloquenceNidus compactness (Needs consideration)Posterior fossa AVM: not usefulDifficulty in comparing modality other than surgery(Only applicable for surgical outcome)No homogeneity in Grade III AVM
Progressive headache visual disturbance personality change( female) Modified Dandy criteriaFriedman and Jacobso1. Symptoms of raised intracranial pressure (headache,nausea, vomiting, transient visual obscurations, orpapilledema)2. No localizing signs with the exception of abducens(sixth) nerve palsy3. The patient is awake and alert4. Normal CT/MRI findings without evidence ofthrombosis5. LP opening pressure of >25 cmH2O and normalbiochemical and cytological composition of CSF6. No other explanation for the raised intracranialpressure
Drug RelatedCauses of Increased ICP• Tetracycline. Minocycline, Doxycycline• Nitrofurantoin• Isotretinoin• Tamoxifen• Nalidixic acid• Lithiu• Steroid withdrawal• Anabolic steroids•Growth hormone• Vitamin A. Systemic Causes of Increased ICPAnemia (severe) Malignant hypertension Cushings and AddisonsHypoparathyridism Sleep Apnea Chronic renal failure