Transcript Angiography/ Interventional Basics

Angiography/
Interventional Basics
How do we perform an angiographic
procedure?
Dr. ABEER FAWZY EL-SOBKY
MASTER of RADIOLOGY
Types of angiography
Conventional
angiography
Digital
subtraction
You can see the
bony skeleton
The bony
skeleton is
subtracted
CT
angiography
© Vascular 2007
MR
angiography
Index
2
So advanced CT, US and
MRA
techniques
made
conventional angiography
limited
to
therapeutic
purposes (Angioplasty).
Technique
of
angiography
Personnel in the Angio Room
 Radiologist ( or other specialist)
 Cardiovascular nurse
 2-3 Radiologic Technologists (CV)
 Sometimes Anesthesiologist depending
on the procedure
Technologist Responsibilities
 Prepare Room/ consent forms
 Provide radiographic positioning / Dr Assistance
 Knowledge of exam, anatomy, pathology
 Prepare sterile tray, prep patient
 Knowledge of catheters and guide wires
 Know sterile technique/ safe clean up
 Monitor ECG + pressure
 Patient care skills and pharmacology
Angiography/ Interventional/
Cardiovascular
 Procedure Room
(Suite)



Room size- 400600 square feet
Easily cleaned
(floors, wall, etc.)
Outlets needed for
O2, suction.
 Control Room
 100-150 square feet
 Easy access and
communication to
procedure room
 Computers, monitors and
un sterile personnel
 Storage area- guide
wires, catheters and
needles
Equipment found in all
Advanced Procedure Rooms
 X-ray generators
 Controls
 X-ray Tubes
 System to record events of procedure
 Automatic Injectors
X-Ray Tube Requirements
 Detail
 Withstand high heat- rapid exposure
sequences
 Use smallest possible focal spot
Equipment Requirements
 High heat load tubes w/ rapid cooling

Series imaging (up to 3-4 films/sec),
intense heat
 Analog- to- Digital Conversion System
 Programmable digital image acquisition
system
 PACS
 Electromagnetic Injectors
 Monitoring Equipment- BP & ECG
 Island Tables- access from all sides,
height adjustments, floor controls
 Tables do not usually tilt
Digital Imaging- Analog VS
Digital Concepts
 Analog- image seen after chemical
process
 Digital- image manipulated by software

Information changed through use of
computer algorithm
Digital Subtraction
Angiography (DSA)
 Computer “ subtracts” out all anatomy
except contrast-filled vessels
 Looks like a reverse image
 Can be more diagnostic for vessels (
clots, constrictions)
Electromechanical Injector
 Used in Angio, CT, MRI
 Overcome arterial pressure + maintains
bolus
 Maintains flow rate
 Flow rate affected by




Viscosity
Length + diameter catheter
Injection pressure
Vessel selected
Seldinger Technique
 Method for catheterization of vessels
 Developed 1950’s still popular today
 Percutaneous (through the skin)
technique for arterial and venous access
 3 vessels considered:



Femoral –preferred site for arterial (size +
accessibility)
Brachial
Axillary
 Selection based on
strong pulse w/
absence of disease
 Site cleaned, area
draped, local given
Seldinger Technique ( step-bystep)
 Insertion of needle
 Placement of needle in lumen
 Insertion Guide wire- thru needle, advance 10
cm
 Removal of Needle- guide wire in position
 Threading of catheter to area of Interest- fluoro
used
 Removal of guide wire- catheter remains in
place
SELDINGER TECHNIQUE
 Two less common methods used


Cut down- minor surgical procedure to
expose vessel of interest
Translumbar- patient prone, long needle
passed thru T12- L2 into aorta
Let’s Look at Needles, Guide
wires and Catheters
 Cannula
 connecting hub (luer
lock)
 Baseplate
 transparent tubing
Guidewires
 Guide catheter for placement in vessel
 Guide wire diameter be large enough so blood
can not flow back for too long a time
 Tips at the end of GW


Straight
J- tipped
 longer G.W. for selective angio vessels
 Short used for shorter direct vascular approach
GUIDEWIRES
CATHETERS
Straight- end hole only
 Pigtail- circular tip w/ multiple side
holes to reduce whiplash and control
contrast
 Sidewinder- curved to facilitate vessel
selection
 Cobra- variation in curvature to facilitate
selection of vessels

 The more holes at the end / the more
contrast used/ large vessels
 Catheter with only end hole/ smaller
vessels/ carotid
 Combo end and side holes reduce risk of
trauma to vessel, enhances contrast
CATHETERS
Interventional Imaging
Procedures
 Intervene w/ disease, provide
therapeutic outcome
 Purpose/ benefits




Lower risk compared to surgery
Less $
Shorter hospital stay and recovery
Alternative for non surgical patient
Preparation to procedure
 Anti coagulants- what do these do?
 Consent form
 NPO 8 hours
 Lab tests to test kidney function?
Post Procedure Care
 Catheter removed – compression
applied
 Bed rest- min 4 hrs/ head elevated 30
degrees
 Vital signs
 Extremity watch
Radiation Protection
 > radiation dose to angio team- fluoro
 Proximity to patient
 Radiation protection devices
 Leaded glasses pulled into place
 Minimal fluoro use as possible
 Collimation
 Angio personnel wear badges and ring
monitors
Contra Indications
 Contrast allergy
 Impaired renal function
 Blood- clotting disorders
 Anti coagulant medication
 Unstable cardio pulmonary/ neurological
status
Risks/ Complications
 Bleeding at puncture site
 Thrombus formation
 Embolus formation –plaque dislodged
from vessel wall by catheter
 Dissection of vessel
 Puncture site infection ( contaminated
sterile field)
 Contrast reaction