angiography basics and seldinger technique
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angiography basicsTRANSCRIPT
Angiography/ Interventional Basics
How do we perform an angiographic procedure?
Dr. ABEER FAWZY EL-SOBKYMASTER of RADIOLOGY
© Vascular 2007 2
Types of angiographyTypes of angiography
Conventional angiography
Digital subtraction
CT angiography
MR angiography
You can see the bony skeleton
The bony skeleton is subtracted
Index
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- 400-
600 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-by-step) 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