Angiography basics

Angiography/ Interventional Basics

What do we visualize with an angiographic procedure?

Personnel in the Angio Room

http://www.heartsite.com/html/cardiac_cath.html

Radiologist/ Specialist Cardiovascular nurse 2-3 Radiologic Technologists (CV) Sometimes Anesthesiologist

Angiography/ Interventional/ Cardiovascular

Procedure Room (Suite) Room size- 400-600 square feet Easily cleaned Why? Outlets needed for O2, suction, crash cart 3 means of access to the room (Bushong,

p. 374) What are they?

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

Generator

700MA- 1500MA Short exposure times Able to generate 80- 100 KW power Limit motion Provide max. contrast

X-Ray Tube Requirements

Detail Withstand high heat- rapid exposure

sequences Tube rating charts posted Need max. detail for vessels Use smallest possible focal spot Decrease target angle, p.13…line focus

principle

Equipment Requirements

High heat load tubes w/ rapid cooling Series imaging, intense heat SPEED UP THE ANODE RPM

1-2 Track mounted tubes Analog- to- Digital Conversion System Programmable digital image acquisition

system (rate,sequencing, processing) PACS

Electromagnetic Injectors Monitoring Equipment- BP & ECG Island Tables- access from all sides,

height adjustments, floor controls Where are the cables? Tables do not usually tilt

Digital Acquisition

2 types 1. Analog-to-Digital

Radiation-pt-intensifier-light-TV-light to electrical signal- analog-to-digital converter- image processor

2. Flat detectors Charged coupled devices (CCD) computer

chip Direct digital conversion

Charge Coupled Device (CCD)

Silicon computer chips Converts light to digital image Lower noise Better contrast Lower patient dose Advantage to this type system- images

produced in low light w/o loss of resolution

Digital Imaging- Analog VS Digital Concepts

Analog- image seen after chemical process

Digital- image manipulated by software Relates to numbers Number table called an array Information changed through use of

computer algorithm Advantages of Digital Angiography, p.30

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) Imaging systems below now mostly

replaced by digital Cut Film Changer Cine Fluoro( Cardiac Cath Camera)

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

Components Control panel Syringe Heating Device High- pressure mechanism

Safety Devices Acceleration regulators Pressure- limiting devices MRI- non- ferrous material

Vocabulary Terms

Arteriosclerosis- vessels hardened Atherosclerosis- plaque like cholesterol Thrombus Embolus Occlusion Tumor Stenosis Angioplasty-angio procedure dilates stenosed

vessel

Lithotripsy Stent- cage like metal device placed in

vessel to maintain blood flow Thrombolysis Filter Embolization- stop bleeding, cease

blood flow to site of pathology Ante grade Retrograde

Seldinger Technique

Method for catheterization of vessels Developed 1950’s still popular today Percutaneous (through the skin) 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

Contents of Procedure Tray

Variety items 3 basic groups of equipment Prep Group Anesthetic Group Insertion and removal Contrast

Accessories Adaptors Connectors Manifolds, Stopcocks

Let’s Look at Needles, Guide wires and Catheters Cannula stilette connecting hub (luer

lock) baseplate two or three-way

stopcock transparent tubing

Guidewires

Guide catheter for placement in vessel Diameter 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

CATHETERS

Straight Pigtail Sidewinder Cobra

The more holes at the end / the more contrast / large vessels

Catheter with only end hole/ smaller vessels/ carotid

Combo end and side holes reduce risk of trauma to vessel, enhances contrast

Vascular/ Non- Vascular Studies Embolization pg 711,

Bontrager Stent Placements PTA pg 712 ,

Bontrager Vena Cava Filters Thrombolysis

Biopsies Fluid Drainage Injection of

Medicines Tube Placement in

Organs or Cavities Bontrager, pg 716

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

Post Procedure Care

Catheter removed – compression Bed rest- min 4 hrs/ head up 30 degrees Vital signs Extremity watch Some angiographic procedures:

angioplasty, venography, angiocardiography, lymphography

Radiation Protection

Proximity to patient Radiation protection devices Leaded glasses pulled into place Minimal fluoro use Collimation Wear badges and ring monitors

Risks/ Complications

Bleeding at puncture site Thrombus formation Embolus formation –plaque dislodged Dissection of vessel Puncture site infection ( contaminated

sterile field) Contrast reaction