interventional/cath lab pathologies and applications

Interventional Radiology

procedures using fluoroscopic imaging, treatment element usually involved

Angiogram

examination of blood vessels using contrast

Angioplasty

treating blood vessels with balloons and stents, occurs following/alongside angiogram

Embolisation

delivery of coils/beads/other devices to occlude a blood vessel, treats bleeding

EVAR

endovascular aortic repair

treatment of aortic aneurysm/dissection by stenting aorta

uses pump to inject large amount of contrast

Fistulogram

contrast imaging of fistula in arm

Fistula

surgical connection of artery and veins in arm to provide a suitable target vessel for dialysis

increased pressure from artery widens vein

takes place in upper and lower limb

Benefits of a fistula

more reliable for dialysis so it can be cannulated more without disappearing

Disadvantages of a fistula

can affect blood pressure readings

Nephrostomy

insertion of drain percutaneously into kidney to drain urine

PICC Insertion

insertion of central catheter from arm, positioned in vena cava

PTC

percutaneous trans-hepatic cholangiography

contrast injected to examine bile duct

stents/drains may be inserted to drain bile

When is PTC used?

when ERCP cannot be done

when condition is more acute to stabilse patient before more permanent solution can be done

Coronary Angioplasty

treating coronary arteries with balloons and stents, occurs following/alongside an angiogram

Electrophysiology Study

insertion of catheters into the chambers of the heart to assess for arrythmias caused by abnormal electrical pathways or rhythms

Cardiac Ablation

burning or freezing of cardiac tissues to adjust conductivity and restore normal rhythm

can follow electrophysiology study,

What occurs during Cardiac Ablation?

infarction caused in very small section to revert tissue into nonconductive insulated scar tissue

Pacemaker Insertion

insertion of a device to maintain a safe heart rate

usually placed left pectoral region

axillary/cephalic/subclavian veins used for insertion

leads sense electrical activity and paces (delivers electrical activity)

TAVI

Trans-Catheter Aortic Valve Insertion

insertion of prosthetic aortic valve under fluoroscopic guidance

treats aortic stenosis

Which arteries are involved in a TAVI?

done through femoral artery or brachial/axillary artery, must use very large artery to fit large catheter

Modalities used in TAVI procedure

CT for surgical planning

fluoroscopic imaging during

ultrasound before and after  

AO

Anterior Oblique

LAO

Left Anterior Oblique

LAO CAUDAL

spider projection, steep diagonal angle through throrax, high dose

How to combat high dose associated with LAO CAUDAL view?

collimation

reduce angles, can also improve clarity

RCA

right coronary artery

RCA Projections

PA CRANIAL, RAO, LAO

LCA Projections - Four Corners

RAO CRANIAL, LAO CRANIAL, RAO CAUDAL, LAO CAUDAL/SPIDER

Why is it important to take multiple projections of of the coronary arteries

difficult to fully represent 3D structures in 2D images - foreshortening occurs

some pathologies eccentric rather than concentric - may not be visualised in all projections 

Seldinger Technique

method to access target vein/arteries 

1. puncture vessel using hollow needle (often under ultrasound guidance) 

2. advance guidewire into vessel 

3. hold guidewire securely in place and exchanging needle for a sheath of requisite size 

4. guidewire removed leaving sheath in situ – catheters can be advanced and exchanged 

injector pump

used to inject a large volume of contrast quickly

can provide specified volume of contrast at a particular rate

used to repeatedly inject a consistent volume of contrast

used when imaging left ventricle/aorta/bilateral femoral arteries