Week 3 Flashcards
Which modality is the gold standard for preoperative assessment of patients for carotid intervention
Arteriography
What other modalities are used for cerebrovascular disease
Plain CT Contrast arteriography MRA CTA Digital subtraction CTA
What does non-invasive mean
No contrast agents
No catheter related complications
What is arteriography used for
Catheter based technique
Stroke/death rate 0.2%-0.7%
This does not answer the question..oops
What do we assess with arteriography
Aortic arch, SCA, and carotids (int and ext)
Plain CT
Provides 2 and 3 dimensional images to identify silent infarcts, determining the timing of surgery, evaluating the risk of surgery, and r/o other causes of disease or symptoms
What is CTA good for
Highlights the cerebrovascularity
Invasive –uses contrast
What method visualizes the entire cerebral arterial system
Digital subtraction
Is MRA preferred over duplex and angiography?
No
What is the downside for MRA
It can overestimate the extent of the disease in turbulent flow areas
Is MRA invasive?
No
Angioplasty
Technique of mechanically widening narrowed or obstructed arteries
Usually because of arteriosclerosis
What is the process for an angioplasty
Empty and collapsed ballon on a guide wire (balloon catheter) is put into the narrow location
Inflated using water pressure to 75-500x normal
Balloon expansion of inner plaque and muscle wall
Balloon is then deflated and removed, and a stent may or may not be inserted at this time
What happens to the Doppler signals post stenting?
Alteration in biochemical properties
Can cause increase in velocities
Turbulence can be expected
Is an abrupt increase in PSV normal ?
No–should be gradual
PSV can increase throughout the patent area up to
150cm/s
A velocity increase across the stent at a __:___ ratio identifies a degree of _______
2:1, restenosis
Why is the stent assessed after the procedure?
To look for intimal thickening, restenosis, or plaque/thrombus formation
What’s the criteria for CEA (endarectomy) and CAS (stenting)?
Symptomatic- 50-99%
Asymptomatic- 60-99%
The risk of stroke/death in asymptomatic patients for a procedure must be
< 3%
When should CAS be done in asymptomatic patients?
When they’re at high risk for intervention or with a life expectancy of < 3yrs
What’s the grading criteria of those with a 50-69% stenosis?
PSV >125cm/s
EDV <110cm/s
Ratio >2 <4
What’s the grading criteria of those with a 70-79% stenosis?
PSV >270 cm/s
EDV >110 cm/s
Ratio >4
What’s the most important thing that should be ruled out following revascularization?
Restenosis
PSV ratio measurements are taken
Pre and during stenosis
What are the complications associated with CEA:
RRODHIPI (acronym)
Intimal flap Dissection Residual plaque at the end of CEA site Occlusion Infected patch Hematoma Pseudoaneursym Restenosis
What Doppler (C and P) signs will you see with a PSA?
Yin Yang
To-and-fro
What does coarctation mean
Narrowing
Where is aortic coarctation most common?
Aortic arch– usually where the ductus arteriosus inserts
Can be pre or post ductal
What amount in pressure difference can be used to assess efficacy of surgical intervention?
70mm/Hg
Patients with coarctation of the thoracic aorta may not have claudication and little/no change in ankle pressure following exercise. True or false
True–because of collaterals
What’s the treatment for coarctation?
Angioplasty or end-to-end anastomosis (removes narrowed portion)
What are common causes of stroke?
Atrial fibrillation
Hardening of arteries
High BP
What are the less common causes of stroke
Vasospasm
FMD
Radiation induced vasculopathy
Ischemic stroke
Occur as a result of an obstruction within a blood vessel supplying blood to brain
What’s the underlying condition of ischemic stroke?
Arteriosclerosis
What are the 2 types of obstruction that can occur with ischemic strokes?
Cerebral thrombus
Cerebral embolism
Cerebral thrombosis:
refers to a thrombus that develops at the clogged part of the vessel in the brain (from arteriosclerosis)
Where is a cerebral embolism typically from?
Heart or large arteries–such as carotids
Vasospasm causes
Restriction in blood flow
Cerebral (brain) vasospasm may happen after an operation for a bleed that occurs between the brain and the thin tissue covering the brain (subarachnoid hemorrhage). Vasospasm typically occur ________ days after subarachnoid hemorrhage.
4-10
AVM:
Tangle of blood vessels where blood bypasses the tissue and goes straight from arteries to veins
AVM’s are more common in
Men
Over 15 years, the total chance of an AVM bleeding into the brain, causing damage and stroke is
25%
AVM’s cause patients to experience what?
Localized pain in head due to increased blood flow
Cerebral aneurysm is
Weak or thin spot on a blood vessel in the brain that balloons and fills with blood. This can put pressure on a nerve or surrounding tissue
Brain aneurysms only occur in those over 40. True or false
False, can occur at any age
also mostly women
Cerebral aneurysm most commonly occur in people 40-60years of age. True or false
False – 30-60
What are the risk factors of CA?
Hypertension
Alcohol abuse
Drug Abuse–cocaaaine
Smoking cagrettes
More commonly, cerebral aneurysm ruptures can cause a
Subarachnoid hemorrhage–space between bone and brain
What is the most common type of arrhythmia?
Atrial fibrillation
What is the significance of atrial fibrillation?
Blood pools in atria and is not completely pumped to ventricles. Stasis causing clotting, thrombus forms and embolism ensues
CHF is treated with?
Anticoagulation therapy
CHF is associated with thrombus formation and risk of stroke how?
Hypercoagulable state
Which side of the heart is a thrombus more aggressive?
Right – needs embollectomy or lytic therapy
What is the most common cause of stroke in young adults?
Carotid artery dissection
What are the 2 classes of CA dissection?
Spontaneous
Traumatic
What may occur simultaneously as the dissection may be through the tunica adventia?
PSA
What is treatment for carotid dissection?
Observation, anti-coagulation, stent implantation and carotid artery ligation
Severe flow disturbances in a dissection are caused by
Intimal flapping
What’s the most specific US sign for arterial dissection?
Double lumen sign
What’s the difference between a aneurysm and a pseudoaneurysm?
A- when walls are intact but stretched
PSA- vascular mass that results from a hole in the arterial wall with circulating blood flow, confined by soft tissue and hematoma
Pseudoaneurysms present patients with
Palpable pulsatile mass
What are the causes of CCA PSA?
Blunt trauma
Infection/vasculitis
Iatrogenic
What are the causes of an ICA PSA?
Trauma
Head/neck surgeries
Metastatic lymph nodes
What’s a fistula?
Opening that connects two epithelialized structures
Usually occurs from trauma
What is the most common arterial injury? (iatrogenic)
Carotid artery puncture.. usually leads to PSA and fistulas
What is a Doppler sign for AVF?
Aliasing –arterial and venous flow simultaneously
Flow proximal to the AVF will have what waveform?
Mono
Flow in the injured artery, distal to the AVF will show what?
Normal flow
Flow within the vein will appear (AVM)
Arterialized – lack of phasicity
