1. Neurointervention is a minimally invasive technique for treating vascular lesions of the central nervous system using catheter-based procedures. 2. Some common indications include treatment of aneurysms, large vessel strokes, vascular malformations, and preoperative tumor embolization. 3. Key procedures involve using microcatheters and embolic agents to treat conditions like aneurysms, often utilizing techniques like coiling, stenting, or flow diversion to prevent rupture and reroute blood flow. Precise navigation within the cerebral vasculature is crucial.

1. Dr Girish Gunari
Moderator – Dr Ram Prakash HV
Neurointervention Radiology

2. Neurointervention Radiology
Definition :
Neurointervention is a subspecialty of neurosciences
which offers a minimally invasive therapy for the
vascular lesions of the central nervous system.

3. Historical Aspect
Diagnostic cerebral angiography was
developed by Egaz Moniz in 1927
In 1964, Luessenhop and Velasquez
performed the first catheterization of
intracranial vessels

4. Indications of Neurointerventional Therapy
1.Aneurysm treatment:
both ruptured as well as unruptured aneurysms.
2. Large vessel stroke:
3. Vascular malformations:
arteriovenous malformations (AVMs),
dural fistulas, and venous anomalies.
4. Preoperative tumor embolization.
5. Others: epistaxis, vertebroplasty, kyphoplasty,
etc

5. Devices,Drugs,
and
Material
Used in Neurointervention

6. 1]Complications during a neurointerventional procedure is
thromboembolic
perioperative anticoagulation therapy is vital
Periprocedural Anticoagulation with Heparin
A]Initial bolus dose is 60 to 80 U/kg -Followed by 20 to 40 U/kg
every hour, (Aim to maintain activated partial thromboplastin
time of 2 to 2.5 times the baseline value [30-40sec])
B]Exception to the use of heparin is in subarachnoid
hemorrhage where anticoagulation is deferred until one or two
coils are deployed to secure the aneurysm
C]All the catheters and sheaths should also be continuously
flushed with heparinized saline (1,000–2,000 U in 1 L) with the
help of pressure bags

7. 2]Antiplatelets
To prevent thomboembolism during and after
the procedures.
Dual antiplatelets given when devices such as
flow diverters and stents devices are used.
Oral antiplatelet agents used : Aspirin,
clopidogrel and prasugrel

8. 2]Antiplatelets
B] Intravenous antiplatelet agents are used
when rapid effect is required such as
1]Stent thrombosis
2]thromboembolic complications.
Common intravenous (IV) antiplatelet
agents are Abciximab, integrilin and
eptifibatide,

9. 3] Catheters
Various catheter types include
I] Used to access the targeted large vessel
A]Diagnostic catheters
B] Guiding catheters,
II] To Navigated to the vessel of interest in the intracrania
circulation
C]Distal access catheters,
D] Microcatheters.

10. A] Diagnostic catheters are usually 90 to 100 cm in length,
4F to 6F in size,
Available in various tip shapes such as
Straight tip, angled, Simmons (1, 2, and 3), Osborn (1 and
2), Headhunter type
.

11. Guide catheters
wide lumen and long length catheters
Available in 6F to 8F size and 110 to 135 cm
length.
Their aim is to provide access to large vessels and
support to microcatheter which is used to reach to
the site of interest in cerebral vasculature.

12. Distal access catheter :
is a newly developed set of catheters with
extreme navigability and trackability
The larger lumen distal access catheters :
are also used as aspiration catheters for the
treatment of stroke, due to their easy and
rapid navigation characteristics.

13. Microcatheters are soft and floppy as they are
designed to be least traumatic.
Once stable position is achieved with a guide
catheter or distal access catheter, microcatheters are
then advanced to the exact site in the cerebral
vasculature.
Micro catheter flexibility, stability, and intended use of
such
1]Coil deployment,
2]Liquid embolization,
3] Stent deployment

14. 4] Wires
They are the stainless steel metallic structures that
guides the catheter through the blood vessels for
placement.

15. For diagnostic procedure,
Most commonly, hydrophilic 0.035-inch angled
guidewire is used,
Stiff guidewires (0.038 inch) are used in the
presence of a tortuous anatomy.
Microwires have a diameter ranging from 0.007
to 0.021 inch.
They are used to navigate microcatheters,
balloons, stents,
and other devices intracranially.

17. 4]Embolic Agents
Therapeutic or preoperative embolization in
treatment of many head and neck and
intracranial vascular lesions such as
1]AVMs,
2]fistulas,
3]hypervascular tumors.

18. Embolic agents are basically divided into two
groups
according to their duration of action
I]Temporary agents
Gelfoam, collagen,and thrombin.
II]Permanent agents
1]Particles (polyvinylalcohol [PVA]),
2]coils (pushable, injectable, and detachable),
3]liquid agents (glue, alcohol, and onyx),

20. Basic Steps in Diagnostic and Therapeutic
[Seldinger technique] Neurointerventional
Procedures

21. ANEURYSMS
INTRACRANIAL ANEURYSM
• PEVELANCE OF 0.5% - 6%
1] ASYMPTOMATIC - NEVER DETECTED OR
INCIDENTALLY DETECTED
2] SYMPTOMATIC
3]RUPTURE AND SAH

24. Simple Coiling
Detachable coils were invented by Guglielmi in the
1990s.
Transluminal navigation of a microcatheter into the
aneurysmal dome.
with the help of microguidewires
Delivery and packing of detachable coils within the
aneurysmal sac.
Desirable dome-to-neck ratios (>2.0)
The goal in coiling is to achieve dense packing and
induce rapid blood clot formation within the aneurysmal
sac, hence isolating it from active circulation.

25. Double Catheter Technique
Double catheter technique is for dome-to-neck
ratio (≤2.0, >1.5).
2 microcatheters are positioned in
One in proximal and other in distal aspects of
the aneurysmal dome.
The first coil is deployed in proximal to create
a supporting frame,
then the rest of the coils are deposited via the
distal microcatheter.

26. Balloon-Assisted Coiling
Balloon-assisted coiling (BAC) was initially described
by Moret in 1997 in treating wide neck anyrysum
The BAC was used frequently in dome-to-neck ratio
(≤1.5, >1.0).
# Intraoperative aneurysmal rupture rate was higher
in BAC group than simple coiling

28. Stent-Assisted Coiling
The Stent-Assisted Coiling for of wide-necked
anyrysum
dome-to-neck ratio (≤1.0)
There is need of permanent support to prevent coil
prolapse and migration. Which is provided by stent
a stent is deployed to block the aneurysmal neck
before coil packing.

29. 1] simple Stent-Assisted Coiling
This is also referred to as mesh technique.
A stent is deployed
then a microcatheter is navigated into the
aneurysmal lumen via the mesh of the stent.
Coils are delivered through the microcatheter.

30. 2]Stent jail technique
the microcatheter is positioned before the stent bridging
over the aneurysmal neck
There is no difficulty in holding the microcatheter’s
position during coil packing as it is trapped by the stent.
Disadvantage :However, stent migrations were reported to
have occurred during retrieval of the microcatheter.

31. semi-jailing technique
Stent is semideployed during coiling only fully
deployed after retrieval of the microcatheter.
This enables readjustments of the stent position in
case of migration.

32. Stent jack technique
Stent deployed
fully (or
partially)bridging
the neck, pushing
the coil into the
sac
self-expandable
stent navigated
across the
aneurysmal neck
and microcatheter
into the
aneurysmal sac;
first coil deployed
better coil wall positioning

33. Y-stenting technique
Y-stenting technique is developed for treating anyrysum at
bifurcation
where 1 microcatheter are in place with 2 stents blocking the
aneurysmal neck
It is by far the best technique for treating bifurcation basilar artery
aneurysms.
it is impossible to block the neck with just 1 stent without leaving
the contralateral PCA vulnerable to coil prolapsed and migration.

34. Flow-Diverting Stent
placement of a high-mesh density stent (flow diverter)
in the parent vessel
disrupts blood flow into the aneurysm
allowing for progressive intra-aneurysmal thrombosis
over time
with subsequent obliteration of the aneurysm
Additionally, the flow diverter provides a scaffold for
neoendothelialisation, which treats the weakened
abnormal arterial wall

36. Other treatment methods
Simple Clipping
Aneurysmal neck is exposed by via craniotomy
Exclusion of the entire abnormal vascular wall from
the circulation using single or multiple clips.
Two principles apply in surgical clipping:
1]Isolating the lesion from active
circulation
2]Maintaining the integrity and patency of the
parenting vessel.
.

37. Bypass Techniques
Extracranial-to-intracranial bypass
Principle
It isolates of the lesion via occlusion of the inflow artery and
resumes regional circulation via a bypass from an
extracranial artery to the distal branch of the occluded
artery.
There are 2 types EC-IC bypasses.
low-flow bypass.: The superficial temporal artery (STA) to
an intracranial artery (STA-IC) bypass
High-flow bypass which connects the common carotid artery
(CCA) or external carotid artery (ECA) to an intracranial
artery (CCA-IC or ECA-IC) using a conduit: the great
saphenous vein (GSV) or radial artery (RA).

40. Intracranial-to-Intracranial Bypass
It consists of excision of the lesion and
recanalization of the inflow and outflow
arteries, with or without grafting.
It requires the donor and recipient
arteries to lie parallel and in close
proximity to allow a tension-free
anastomosis.
.

41. There are 3 common sites in the cerebral circulation that are
anatomically suitable for IC-IC bypass
(1) the ACAs, A2 and A3 segments, as they course over the genu and
rostrum of the corpus callosum;

42. 2]the MCA branches, through the sylvian fissure;

43. 3) the posterior cerebral artery (PCA) and
superior cerebellar artery, the section around
midbrain through ambient cistem

45. Case 1 : An Eighty four year old lady
presented with subarachnoid
haemorrhage

46. DSA angiogram images showing
small, lobulated and broad neck
basilar top
aneurysm.

47. Subclavian artery
injections showing
marked tortuosity
and loops in both
vertebral arteries

49. Case 2
54-year-old lady presented with headache.
CT head revealed subarachnoid haemorrhage in the
basal cisterns.

50. DSA revealed a small broad-neck
aneurysm of left posterior cerebral artery (PCA).

51. Evolution of
Neurointerventional in stroke
therapies for Stroke

56. “TIME IS BRAIN:
SAVE THE PENUMBRA” Penumbra is
zone of reversible ischemia around core
of irreversible infarction
Penumbra damaged by: •
1]Hypoperfusion
2]Hyperglycemia
3]Fever
4]Seizure

57. MTT = cerebral blood volume
(CBV) / cerebral blood flow
(CBF)
Time-to-peak (TTP) is the time at which
contrast concentration reaches its
maximum.

64. Alberta stroke program early CT
score (ASPECTS)
10-point quantitative topographic CT scan
score used in patients with middle cerebral
artery stroke.
It has also been adapted for the posterior
circulation

65. caudate
putamen
internal capsule
insular cortex
M1: "anterior MCA cortex," corresponding to
frontal operculum
M2: "MCA cortex lateral to insular ribbon"
corresponding to anterior temporal lobe
M3: "posterior MCA cortex" corresponding to
posterior temporal lobe
M4: "anterior MCA territory immediately
superior to M1"
M5: "lateral MCA territory immediately superior
to M2"
M6: "posterior MCA territory immediately
superior to M3

68. Evolution of Acute ischemic stroke
Treatment
Intravenous thrombolysis
NINDS (National Institute of
Neurological Disorders and Stroke)
study showed V-rtPA treatment was
shown to benefit patients presenting
within 3 h of symptom onset.

69. ECASS (European Cooperative Acute Stroke studies
established IV-rtPA as a standard therapy for patients
with Acute Ischemic Stroke within 4.5 h of symptom
onset
limitations of IV rtPA:
• Narrow therapeutic time window of 4.5 h is the most
common reason that patients do not receive IV-rtPA,
• Unresponsiveness of large thrombi to enzymatic
digestion, resulting in a low recanalization rate
To overcome these major limitations of IV-rtPA,
endovascular approaches have been developed
over the last 2 decades

71. INTRA-ARTERIAL THROMBOLYSIS.
PROACT (Prolyse in Acute Cerebral Thromboembolism Trial
efficacy of intra-arterial recombinant
prourokinase (IA-proUK) and heparin compared with intra-arterial heparin
alone within 6 h of stroke symptom onset in patients with middle cerebral
artery occlusion
functionally
independent
outcome
Recanalization
prourokinase (IA-
proUK) and heparin
60%
40%
intra-arterial
heparin
18%
25%

72. MECHANICAL THROMBECTOMY
“Mechanical embolus removal in cerebral ischemia”
(MERCI) device
8 h of symptom onset
corkscrew-shaped nitinol wire
FDA approval of the MERCI device in August
2004,

73. Mechanical embolus
removal in cerebral
ischemia” (MERCI)
device

74. Thromboaspirationn

75. Recanalization
Neurological outcome
Mechanical embolus
removal in cerebral
ischemia”
(MERCI) device
46%,
27.7%
PROACT.
18%
60%

76. New advances
STENT RETRIEVERS
Stent retrievers were formerly designed for
purpose of
Later
it was realized that these devices are also very
effective in capturing naturally occurring
thrombus and could have a major effect on
early vessel recanalization