Angio C and D Flashcards
basic instruments needed in seldinger technique
- puncture needle
- guidewire
- vascular sheath
2 types if puncture
double wall puncture
- soft tissue posterior to artery provides tamponade to stop bleeding
- less chance of intimal dissection
single wall puncture
- graft
- abnormal clotting profile
- risk of dissection
type of puncture needle
- double wall needle (with a sharp stylet)
- single wall needle (without a stylet)
- 18G needle for 0.035inch GW
- 21G needle for 0.018inch GW
what needles are used for a double wall puncture
- blunt outer cannula: 18G, thin walled, 8cm
- sharp bevelled stylet
basic properties of guidewires
- steerable or non-steerable
- length
- stiffness
- diameter
why use steerable GW
- shaped tips
- provide a good torque control
- for selective cannulation
why use non-steerable GW
- allow the catheter to be positioned for CM injection
- not designed to negotiate stenosis or select branch vessels
length of standard GW
150cm
must be longer than the length of catheter
what happens if GW are longer than 150cm
need more time during the interchange of catheters/ guidewires; risk of contamination
what happens if GW are shorter than 150cm
- easy to slipped into the vessel/ catheter
explain the stiffness of guidewires
- stiffness gives support during advancement of catheter
- however, increased stiffness = increased risk
- a very stiff GW used to negotiate a tortuous vessel = more likely to dissect
diameters of guidewire
0.018GW - for small vessel work
0.035GW - for most of the vascular works, will fit most of the 4Fr or 5Fr catheters
0.038GW - for 7Fr catheter
what is vascular sheath
- consists of hollow plastic tube connected to a hemostatic valve with a side-arm for flushing
- sized by the caliber of catheter it will accept
- thin walled –> may kink in obese patient
benefits of vascular sheath
- provide an atraumatic vascular access route
- used in cases where it is likely to have many times of catheter exchange
- better management of puncture site
- to give extra support GW/ catheter at the puncture site
- prevent blood clot forming - the side arm of a vascular sheath, has a hemostatic value, is used for flushing saline and/or heparin
where does the french size measure for catheter and vascular sheath
- Fr size of catheter means outer circumference
- Fr size for vascular sheath means inner circumference
max catheter flow rate tolerant depends on
- french size
- length
- number of side holes
typical maximum flow rate for pigtail catheters
3Fr - 6-8ml/sec
4Fr - 16-18ml/sec
5Fr - 20-25ml/sec
types of catheter
- diagnostic angiographoc catheters
- micro catheters
- drainage catheter
- balloon catheters
- central venous catheters
what is non-selective catheter used for
- non used for vessel negotiation
- used to inject contrast in large-medium size vessels and have multiple side- holes in high rate and volume
- this can be pigtail or straight catheters
- for diagnostic angiogram
what is selective catheters
- shaped to a wide variety of angles to allow selective cannulation of branch vessels of aorta
what is microcatheter
- only 2Fr to 3Fr
- initially developed for cerebral catheterization
- now increasingly used for super-selective hepatic, visceral and peripheral catheterisation
five common type of interventional instruments
- balloon angioplasty
- vascular stents
- embolisation agents
- thrombolytic agents
- atherectomy
purpose of balloon angioplasty
- mechanically widening a narrowed or obstructed blood vessel
- crushes the fatty deposits
applications of balloon angioplasty
- peripheral angioplasty
- renal artery angioplasty
- carotid angioplasty
- cerebral arteries angioplasty
- coronary artery
contraindications of balloon angioplasty
absolute
- recent thrombosis
relative
- patient with uncontrolled bleeding tendency
- aneurysmal dilatation adjacent to a stenosis
- long occlusion
factors reduce the success of angioplasty and long term patency
- increased length of lesions
- stenosis vs occlusion
- concentric vs eccentric
- ostial stenosis vs vessel stenosis
- calcified lesions vs noncalcified lesion
choice of angioplasty balloon selection
- balloon diameter
- balloon length
different types of stenting
- urethral/ prostatic stent
- urinary tract stent
- biliary stent
- peripheral vascular stent
- coronary arteries stent
indications for stent employment
- long segment stenosis
- total occlusion
- unsuccessful PTA
- recurrent stenosis
- ulcerated plaque
- renal ostial lesion
based on lesion characteristics, what are some stent selection criteria
- type of stent
- diameter
- length
- location
- calcification and eccentricity
different types of vascular stents
- balloon expanded stents/ drug eluting stents
- self-expanding stents
- covered stents
when is embolisation agents used
- to control severe internal bleeding
- for blockage of patency
- suppress the cells growth
general complication of using embolization agents
- post-embolisation syndrome
- infection at the embolised area
- reflux of embolic material
two main types of embolic agents
- temporary
- permanent
what permanent embolisation agents is used for a large vessel
metal coils
what permanent embolisation agents is used for a small vessel
- particle
- liquid agents
what temporary embolisation agents is used for a large vessel
gelfoam sponge sheet
what temporary embolisation agents is used for a small vessel
gelfoam particles
objective of a thrombolytic agent
- break down clot
- make clot more soluble
indications of a thrombolytic agent
- myocardial infarction
- ischemic stroke
- massive pulmonary embolism
- acute limb ischemia
contraindication to thrombolytic agents
- previous intracranial bleeding
- uncontrolled high blood pressure
- major or minor hemorrhage
advantages of atherectomy
- less procedure time
- ease of use
- faster patient recovery
- decreased systemic complications
what is renal artery stenosis
- the narrowing of the inner surface of renal artery
- most often caused by atherosclerosis or fibromuscular dysplasia
objective of renal arteriogram
- control hypertension
- prevent deterioration in renal function
indication for renal arteriogram
- acute renal ischemia
- unexplained hematuria
- intrarenal microaneurysm
- evaluation of donour of kidney before transplantation
- identifying source of bleeding after kidney biopsy
contraindications for renal arteriogram
- related to CM and coagulation problems
what is carotid stenosis
- narrowing or constriction of the inner surface of carotid artery, usually caused by atherosclerosis or fibromuscular dysplasia
S&S of carotid stenosis
- carotid bruit indicate a 70% stenosis of carotid artery
advantages of carotid arteriogram
- evaluate entire carotid arterial system
- assess flow dynamics and collateral flow
disadvantages of carotid arteriogram
- invasive
- expensive
- radiation exposure
- potential for ischemic stroke
indication of carotid artery stenting
- assessment of non atherosclerotic disease is suspected
- treatment with stent
objective of IVC filter
placed to prevent significant PE from DVT of the leg, pelvis or IVC
indications for IVC filter
- contraindication to anticoagulation
- complication to anticoagulation
- recurrent PE despite adequate therapeutic anticoagulation
contraindications to IVC filter
- large clots in the vena cava or iliac veins
IVC filters fall into 2 basic categories
- permanent IVC filters
- retrievable IVC filters
disadvantage of a femoral vein approach
- iliofemoral thrombus obstructing the vein
- possible IVC thrombus extension
advantage of femoral vein approach
air embolism is much less likely
advantage of jugular vein approach
- avoid the possibility of attempt catheterization of an occluded femoral vein
disadvantage of a jugular vein approach
- higher chance of air embolism
- eustachian valve can sometimes cause difficulties in GW navigation
how to prevent air bubble from going into brain
table head down
disadvantage of using temporary IVC filters
- anchoring catheter may provide a pathway for introduction of blood borne pathogens
- cause some degree of patient immobility
- catheter may serve as a nidus for thrombus formation proximal to the filter
complications of IVC filters insertion
at insertion
- puncture site bleeding/ thrombosis
- deployment problems
upon removal
- risk of IVC laceration
late complications
- filter migration/ embolisation
- IVC thrombosis
blood supply to liver
- hepatic artery
- portal vein
objective of TOCE
use of oily CM to induce tumour necrosis
benefit of using TOCE
- increase drug conc in the tumour
- HCC cell has affinity for oily contrast
curative indication of TACE
- when first-line treatments are contraindicated
palliative indications of TACE
- for multifocal tumour
- after post-surgical recurrence
contraindications of TACE
- significant liver disease
- occlusion of portal vein
- marked AV shunting from hepatic artery to portal or hepatic veins
TACE after care
- bed rest for 8 hours
- vital signs are monitored
- regularly observe the punctured site
- infusion of IV fluid and antibiotics
- stop metformin for 2 days
- blood test 1 day after
what are the embolisation agents used in TOCE
- lipiodol
- gel foam
- coils
why add gelfoam in the mixture
- lipiodol washed out by rapid blood flow
- gelfoam to decrease blood flow of feeder
