DR. Walid Asaad, MBBS, MD, DABR,CAQ

Diagnostic &Interventional RadiologyKing 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 invasiveLocal anesthesiaEarly 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 placementEmbolizationThrombolysisBalloon angioplastyAtherectomyElectrophysiology

Percutaneous biopsy

Abscess drainage

Percutaneous nephrostomy

Percutaneous Biliary drainage

Radiofrequency ablation

ANGIOGRAPHYThe radiologic examination of vessels after the introduction of a contrast medium.

HISTORYThe 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 PRINCIPLESArterial 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 TECHNIQUESeldinger 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.

GUIDEWIRESGuide 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 preparationExplain procedure & risk to the patient.

History & physical examination.

Lab tests.

Consent

Pre procedure I/V fluids.

Medication to relieve anxiety.

Monitoring during and after procedureECG, Automatic BP measurement & pulse oximetry.

Life saving drugs and equipments.

Immobile for minimum 4hrs after.

Vital signs monitored.

Puncture site inspected.

Contra-indicationsContrast allergy

Impaired renal function

Blood- clotting disorders

Anti coagulant medication

Unstable cardio pulmonary/ neurological status

RisksBleeding at puncture siteThrombus formationEmbolus formation –plaque dislodged from vessel wall by catheterDissection of vesselPuncture 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 .

EQUIPMENTSThe X-ray apparatus for interventional radiology is more massive,flexible,expensive & advanced. More heat load and serial images.

X RAY TUBETwo 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.

GeneratorsHigh frequency and high voltage generators

Three phase,12 pulse power.

Patient couchStationary 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 receptor2 different types.

Cinefluorographic camera—now obsolete.

Nowadays Digital image receptors are used with a television camera pickup tube or a charge-coupled device(CCD).

THANKS