Angiography/ Interventional Basics How do we perform an angiographic procedure? Dr. ABEER FAWZY EL-SOBKY MASTER of RADIOLOGY

© Vascular Types 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 square feet Easily cleaned (floors, wall, etc.) Outlets needed for O2, suction.  Control Room 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