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