DR. Walid Asaad, MBBS, MD, DABR,CAQ
Diagnostic &Interventional Radiology King Abdulaziz University Hospital
INTERVENTIONAL RADIOLOGY &
ANGIOGRAPHY
INTERVENTIONAL RADIOLOGY
A subspecialty which provides minimally invasive techniques with the help of imaging modalities to diagnose or treat a condition.
Minimally invasive
Local anesthesia
Early recovery
8 out of 10 procedures use skin incisions smaller than 5 mm.
9 out of 10 procedures use only local anaesthetic, sometimes with sedation.
Up to 8 out of 10 patients go home the same day
INTERVENTIONAL RADIOLOGY
Stent placement
Embolization
Thrombolysis
Balloon angioplasty
Atherectomy
Electrophysiology
Percutaneous biopsy
Abscess drainage
Percutaneous nephrostomy
Percutaneous Biliary drainage
Radiofrequency ablation
ANGIOGRAPHY
The radiologic examination of vessels after the introduction of a contrast medium.
HISTORY
The first angiogram was performed only months after Roentgen's discovery of X rays.
Which was when?
Two physicians injected mercury salts into an amputated hand and created an image of the arteries
Post mortem injection of mercury salts in Jan,1896.
Interventional radiologic procedures began in 1930s with angiography.
In early 1960s Mason Jones pioneered transbrachial selective coronary
angiography.
Later in 1960s transfemoral angiography was developed.
BASIC PRINCIPLES
Arterial access
In 1953 Seldinger described a method for catheterization of vessels.
A percutaneous technique for arterial and venous access.
Femoral artery is most commonly used.
SELDINGER TECHNIQUE
Seldinger needle.
18gauge single use,sterile needle.
2 parts-- a solid inner needle(stylet) & an outer thin wall needle for smooth passage.
a hub---good instrument balance
winged handle---good control.
Site cleaned, area draped, local anesthetic given.
The seldinger needle is introduced into the artery.
When pulsating blood returns, the stylet is removed.
A guide wire is inserted through the needle.
With guide wire in vessel, needle is removed.
Catheter is threaded onto the guide wire.
Under fluoro, the catheter is then advanced and the guide wire is removed.
GUIDEWIRES
Guide the catheter.
Allow safe introduction of catheter into the vessel.
Made of stainless steel.
Usually about 145cm long
An inner core wire that is tapered at the end to a soft flexible tip.
Covered by a coating—teflon, heparin and
recently hydrophilic polymers(glide wires) are used.
Coating reduces friction, gives strength to GW.
Tips at the end of GW
Straight
J- tipped—prevents subintimal dissection of artery.
CATHETERS
•Many shapes and sizes.
•diameter is given in French(Fr)—
3Fr=1mm.
•Straight- end hole only—smaller vessels/minimal contrast.
•Pigtail- circular tip with multiple side holes —larger vessels/ more contrast.
H1 or Head hunter tip– used for femoral approach to brachiocephalic vessels.
Simmons catheter is highly curved --- for
sharply angled vessels--cerebral and visceral angiography.
C2 or Cobra catheter has angled tip joined to a gentle curve—celiac, renal & mesenteric
arteries.
Judkins catheters
Right(lesser curve) & left(greater curve) for right & left coronary arteries.
Amplatz catheters
Right & left coronary arteries
Contrast Media
Initially ionic iodine compounds were used.
Now non ionic contrast media in practice—
low adverse reactions and low physiologic problems.
INDICATIONS
Diagnosis & presence of ischemic heart disease.
After revascularization procedures
Congenital heart lesions & anomalies of great vessels.
Valve disease, myocardial disease &
ventricular function.
Atheroma
Aneurysms
Arteriovenous malformations
Arterial ischemia
Trauma
Patient preparation
Explain procedure & risk to the patient.
History & physical examination.
Lab tests.
Consent
Pre procedure I/V fluids.
Medication to relieve anxiety.
Monitoring during and after procedure
ECG, Automatic BP measurement & pulse oximetry.
Life saving drugs and equipments.
Immobile for minimum 4hrs after.
Vital signs monitored.
Puncture site inspected.
Contra-indications
Contrast allergy
Impaired renal function
Blood- clotting disorders
Anti coagulant medication
Unstable cardio pulmonary/ neurological status
Risks
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
INTERVENTIONAL RADIOLOGY SUITE
Specifically designed to accommodate the quantity of equipment needed & the large number of people
involved in the procedure.
Interventional radiology suite
Procedure Room
Room size- 400- 600 square feet
Easily cleaned
(floors, wall, etc.)
Outlets needed for O2, suction.
At least three
means of access.
Control Room
100-150 square feet
Easy access and communication to procedure room
Operating console with Computers, monitors .
EQUIPMENTS
The X-ray apparatus for interventional
radiology is more massive,flexible,expensive
& advanced.
More heat load and serial images.
X RAY TUBE
Two ceiling track-mounted X-ray tubes
alongwith an image intensified fluoroscope mounted on C or an L arm.
A large diameter massive anode disc(15cm diameter, 5cm thick) to accommodate heat load.
Cathodes designed for magnification &
serial radiography.
A large focal spot of 1mm for heat load.
A small focal spot( no more than 0.3mm) is necessary for spatial resolution of small
vessel magnification.
Power rating of 80kW—for rapid sequence serial radiography.
Anode heat capacity of 1 MHU—to accommodate heat load.
Generators
High frequency and high voltage generators
Three phase,12 pulse power.
Patient couch
Stationary couch with a floating,tilting or rotating table top.
Controls for couch positioning are located on side of table and also on a floor switch.
May also have a computer controlled stepping capability.
Image receptor
2 different types.
Cinefluorographic camera—now obsolete.
Nowadays Digital image receptors are used with a television camera pickup tube or a
charge-coupled device(CCD).
