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Flashcards in Vascular Deck (119):
1

What does the recurrent artery of Heubner supply?

Anterior putamen, pallidum and internal capsule

2

What deficit occurs if the posterior perforators are injured from an ACom aneurysm

Septal injury resulting in akinetic mutism

3

Branches of PCA 1st segment?

Posterior thalamogeniculate perforators, crural perforators, long and short circumflex

4

Branches of the 2nd segment PCA?

Posterior medial and lateral choroidal A

5

Where is the anterior choroidal artery seen on an AP angiogram?

Lateral to the medial lenticulostriate perforators

6

Where do the Trolard group of veins drain into?

Superior sagittal sinus

7

What is the trans-cerebral venous system?

Cortical link between deep and superficial venous systems

8

What veins join to form the internal cerebral vein?

Thalamostriate, choroidal vein, septal vein and caudate vein

9

Where is the posterior communicating vein?

In the interpeduncular cistern connecting the basal vein of Rosthenthal on each side

10

What are the routes of drainage of the cavernous sinus?

Opthalmic to facial, Super and inferior petrosal to IJV, sphenoparietal sinus to SSS and basal vein of rosenthal to straight sinus

11

Where do the hemispheric veins of the cerebellum drain?

To the transverse sinus
Note medial veins go the BVR and straight sinus

12

What is a large occipital sinus associated with?

Agenesis of the transverse sinuses

13

What is the evidence for recannalisation in stroke?

Improved mortality and morbidity

14

What recannalisation strategies are there for stroke?

Thrombolysis (IV tPA) within 4.5 hours of symptom onset - better for distal vessels and less efficacious for ICA etc
Intra-arterial thrombolysis (tPA or urokinase)
Intra-arterial mechanical thrombectomy (stent retrieval)

15

Which patients will be best candidates for mechanical thrombectomy?

Those without underlying brain injury and extent of collateral arterial supply on 10 second delayed phase CT-A. Only perform thrombectomy on those with good collaterals.

16

What is the time window for endovascular stroke intervention?

Stroke onset

17

What is the evidence supporting carotid endarterectomy?

NASCET study showed 17% risk reduction in the surgical arm if there is >70% stenosis

18

What is the significance of an ulcerated plaque for endarterectomy?

The presence of an ulcerated plaque with higher degree stenosis results in higher risk of stroke and better surgical outcomes

19

What is the significance of an intra-plaque haemorrhage?

Higher risk of stroke

20

What is the evidence for CES vs CAS (stenting)

Stenting is better for younger patients whiilst surgery was better for older patients (>68 years)
Surgery is more risky with higher degrees of stenosis whilst stenting risk remains the same.
(SPACE trial - overall no difference)
CREST - overall no difference

21

What is the risk for treatment of an aymptomatic carotid stenosis >70%?

3% (compared to 11% with medical therapy) - from the ACAS trial

22

What are the indications for by-pass surgery?

1. Flow augmentation / improvement
2. Flow preservation

23

What is the classical bypass surgery?

STA to M4 (proven by international EC-IC bypass study to have no benefit)

24

What are the collaterals in the brain?

Circle of willis
ECA-ICA through meningeal and opthalmic arteries
Pial collaterals (corticomeningeal)

25

What is the typical sign for exhausted cerebrovacular reserve capacity?

Low CBF but increased OEF leads to normal CMRO2

26

What was the COSS study?

Carotid occlusion surgery study

27

What was the outcome of the COSS study?

Bypass improves the haemodynamic function of the brain (OEF on PET) and patency was 96% on long term f/u, but the perioperative stroke rate was 14% so medical treatment is better

28

What is Moya moya?

Progressive occlusion of the ICA resulting in excessive collateralisation

29

What is the Jam trial?

Japanese moya moya study showed revascularisation with EC-IC bypass reduced risk of haemorrhage

30

What is synangiosis?

Indirect revascularisation by overlay with muscle etc. Used alone only in children but in adults only direct STA-MCA methods are used.

31

Would you revascularise a non-symptomatic moya moya patient?

NO

32

How can DAVF and AVM be differentiated?

AVMs are fed by arteries that supply the brain but DAVFs are fed by arteries that normally supply the meninges and the shunt is in the dura not the brain

33

What is the risk of evolution of a benign to malignant DAVF?

2%

34

What are the pathophysiology of DAVF?

Impaired venous outflow of the brain and cortical venous reflux

35

What is the sign of cortical venous reflux with DAVF?

Enlargement of sulcal vessels (not within the parenchyma)

36

What are the signal characteristics of blood with SWI?

Deoxy Hb is dark (veins) but Oxy Hb is bright (arterial)

37

What is the significance of confluent white matter high signal on FLAIR?

In a young patient think venous hypertension

38

What should be thought of in a patient with SAH/ICH and subdural in the absence of trauma?

DAVF

39

What are the treatment options for DAVFs?

Endovascular (transarterial or transvenous)
Surgical disconnection

40

How is a transarterial DAVF occlusion performed?

Via the meningeal (not osteodural) direct feeder to emoblise the distal artery and proximal vein

41

When should a DAVF be treated with transvenous endovascular approach?

If transarterial approach is not possible and only if the vein being used is not important for venous drainage

42

What is the annual haemorrhage rate of an AVM?

2% but up to 4-6% if associated aneurysm

43

What are the features of a DVA?

Dilated veins without dilated arterial feeders and no shunting

44

How are AVMs classified?

Surgical - Spetzler-martin
Gamma-knife - Pollock flickinger
Endovascular -

45

What is the SIMVS?

Scottish intracranial vascular malformation study

46

How do AVMs present?

Haemorrhage 50%; Epilepsy 25% and Focal deficits, Headaches and symptomatic

47

What is the Lawton modification of the spetzler martin classfication?

**

48

What is the risk of AVM rupture according to the ARUBA trial?

1-4% per year

49

What study shows the natural history of AVMs?

Meta-analysis Gross et al 2013 Neurosurgery showed unruptured 2.2% and ruputured 4.5%

50

What factors of AVM are associated with higher rupture risk?

Previous haemorrhage, associated haemorrhage, deep venous drainage and deep location

51

What is the role of AVM intervention?

To prevent rupture risk and not seizure control

52

What is the obliteration rate for AVMs with gamma knife?

70-80%

53

In the ARUBA trial what is the risk of death or stroke with intervention?

30%!! compared to 10% for medical management

54

What is the cure rate of AVMs with embolisation alone?

30%

55

What is the Borden classification

1 - Drainage to sinus only
2 - Drainage to sinus and CVR
3 - Drainage to CVR only (highest risk of haemorrhage)

56

What are the branches of the supraclinoid caroid artery?

Opthalmic, PCom, Anterior choroidal

57

What is the prevelance of aneurysms in the population?

2%

58

What is the mortality of ruptured aneurysm without treatment?

60% at 6 months

59

What is the re-rupture rate of an aneurysm?

6% 2 days
24% 2 weeks
40% 6 months

60

What are the risk factors for aneurysm ruputure?

Age
Female
Posterior circulation
Another aneurysm
Japanese or Finnish

61

What is the incidence of SAH?

7-20 per 100,000 per population

62

What is the risk of surgery for unruptured aneurysms?

10% in ISUIA2

63

What is ISUIA 2?

Prospective study showed
Anterior circ
25 mm 40%
Posterior circ incl PCom

64

What are the problems with ISUIA?

Morphology of aneurysm, growth of aneurysm, smokers, female and Japanese / Finnish not taken into account
Intervention risks are too high

65

What is the chance of recannalisation following coiling?

15-35%

66

What is the retreatment rate for coiled aneurysms?

Up to 13%

67

What factors favour clipping vs coiling?

Location e.g. basilar / SCA / intracavernous / opthalmic etc
Configuration - direction of aneurysm pointing, vessels at neck, perforators, narrow vs wide neck, bifurcation recannalise more with coiling vs sidewall aneurysm, size - very small aneurysms 15mm may compact.
Circumstances - pregnancy, kidney disease, calcification at neck, life threatening situation due to clot / hydrocephalus - fenestration of the lamina terminalis reduces shunt rate from 14% to 4%, vasospasm can be treated via endovascular means
Vessels - other aneurysms in the same surgical field or different regions, anatomical variation, vessel wall disease - marfan's syndrome due to vessel tortuosity
Age - young patients have compaction, old patients have vessel wall pathology
Etiology - Dissection better endovascular, partially thrombosed, trauma, mycotic aneurysm

68

What is the PHASES score?

Aid to prediction of risk of rupture of incidental intracranial aneurysms based on population, hypertension, age, size of aneurysm, previous SAH from other aneurysm and site of aneurysm

69

When does oxyHb become positive in SAH?

2 hours

70

How long does xanthachromia remain 100% sensitive with spectroscopy?

2 weeks (70% at 3 weeks)

71

Is there choroid plexus in the occipital horn?

No

72

What is the fornicial psalterium?

The stretching out of the fornix fibre as they spread apart

73

How can carotid cavernous fistula be malignant?

Cavernous sinus to sphenoparietal sinus goes to supfl Middle cerebral vein and also uncal vein to basal vein of Rosenthal

74

What is the epsilon sign?

The characteristic venous dilatation in patient with a vein of galen malforation

75

How can veins drain with vein of galen malformation

Subcutaneous varix
Cavernous capture - causes fetus face to become veiny and blue
** there are more - look it up

76

What are the side effects of a vein of galen malformation?

High output cardiac failure
Arterial steal causing infarctions, encephalomalacia and melting brain (in neonates)
Developmental delay
Seizures
Haemorrhage ** very rarely if there is cavernous capture and cortical reflux
Hydrodynamic disorders - venous hypertension causes hydrocephalus (do not shunt them as it makes the vein of galen malformation worse!!)
Tonsilar prolapse due to venous hypertension

77

How are vein of galen malformations diagnosed?

Fetal USS shows a dilated median vein of the prosencephalon in the midline
MRI can then be done

78

What is the best time to embolise a vein of galen malformation?

Neonates if heart failure, otherwise 3 months as the vessels as stronger and enough contrast can be used

Inject from the artery into the vein laterally within the artery (not central part as it has highest flow)

79

What does the anterior communicating vein drain?

Joins the anterior BVR bilaterally (superior to the ACom)

80

Where is the sphenoparietal sinus?

Along the lesser wing of the sphenoid and has the superficial middle cerebral vein draining into it

81

Where do the lateral cerebellar hemispheric veins drain?

Transverse sinus

82

How are dural sinuses composed?

Multiple separate channels

83

What proportion of strokes are from cardiac embolus in patients with severe cartoid stenosis?

50%

84

What is the definition of severe carotid artery stenosis?

>75%

85

What is the risk of stroke with stenosis >70%

26% with medical management
9% with carotid endarterectomy

86

What is vessel wall imaging?

Double inversion recovery (black blood)

87

If you have plaque haemorrhage in CES, what is the risk of haemorrhage within one year?

20%

88

What are the features of an unstable carotid plaque?

Thin fibrous cap
Lipid core
Plaque haemorrhage

89

What is the ICSS trial?

Showed CES surgery better than stenting. Other trials showed no differences.

90

What did the SPACE trial show?

Young patients better to have carotid stenting whilst elderly patients better with endarterectomy

91

Where are pial AVMs?

Within the brain parenchyma

92

Where is the shunt in a dAVF?

Within the leaflets of the dura

93

What is the mortality rate with a dAVF with cortical venous reflux?

10-20%

94

What can cause a dural AVF?

Sinus thrombosis

95

What does it mean if you see a venous structure on a TOF?

Arterialisation of a vein i.e. flow is going towards the brain not away

96

How does TOF work?

Saturation of spins in the slab below the brain so only flow going to the head is seen

97

What does it mean if a patient with a DAVF notices the bruit disappears?

The DAVF has developed cortical venous reflux (very rarely it has resolved)

98

When do you do a venous endovascular obliteration of dAVF?

If arterial occlusion is too dangerous and
If the brain does not drain through that vein which will be occluded

99

What is the natural history of brain AVM?

2-4% annual haemorrhage rate
8% if there is a nidal aneurysm
6-15% if previous haemorrhage from the AVM

100

What are DVAs?

Developmental venous anomalies: dilated transcerebral veins without an arterial feeder (associated with cavernomas!)

101

What size AVM is max for SRS?

12 cm^3 (3cm diameter) unless you stage the treatment (will take 3 years to work...)

102

What is a pseudophlebitic pattern?

Increased caliber, number and tortuosity of pial vessels suggesting venous outflow obstruction and collateralisation

103

What does cerebral oedema suggest in a patient with AVM?

Venous congestion (look for a flow aneurysm!)

104

Which AVMs cause IVH?

Ependymal or choroidal artery fed AVMs

105

What is the difference between paediatric and adult cavernomas?

Paediatric cavernomas can be giant!

106

How do you treat a dAVF of the tentorial artery?

Disconnection of the petrosal vein through a retrosigmoidal approach
Venous endovascular embolisation is very difficult

107

How can you decide between a lateral supraorbital vs mini-pterional approach for an MCA aneurysm?

If within 15mm of the ICA bifuraction then lateral supraorbital. If >15 then minipterional

108

What is partial trapping?

A last resort where there is partial inflow obstruction to cause thrombus within the aneurysm that cannot be occluded due to perforators

109

Which aneurysm may be associated with Abluia?

AComm with bifrontal damage

110

What proportion of CT scans are positive for SAH by day 3?

75%

111

How sensitive is xanthochromia for SAH at 2 weeks?

100%

112

What are the types of revascularisation?

Direct - bypass
Indirect = neoangiogenesis

113

What is flow preservation vs augmentation?

Preservation is occlusing and bypassing a region e.g. giant aneurysm, whilst augmentation is adding supply to a compromised territory

114

What happens to oxygen extraction fraction when CPP falls?

OEF rises to maintain CMR02 (Cerebral metabolic rate for O2)

115

How can OEF be measured?

PET

116

What are the methods for revascularisation in moya moya children?

Arteriosynangiosis
Myosynangiosis
Durasynangiosis

117

What is the difference in revascularisation in adults vs children?

Adults need direct revascularisation

118

Should you treat a patient with previous stroke due intracerebral occlusion with reduced cerebral perfusion despite best medical treatment?

Yes - flow augmentation will reduce further strokes

119

How do you know whether you need a high or low flow bypass?

Bypass flow needs to be adequate to replace the flow that is removed or needed