angiography & vascular interventional radiology

Question 1

Seldinger technique: tools

Answer 1

1. puncture needle: 18G (one-part or two-part)
2. guidewire: atraumatic, non-thrombogen, torque control, hydrophilic coating (for difficult cases), variable diameter (0.014-0.038)
3. diagnostic catheters: braided plastic tube, flexible, kink-resistant, torque response, outer diameter is measured in French scale - 1F = 1/3 mm

Question 2

non-selective (flush) Vs selective angiography

Answer 2

selective has improved image quality, uses less contrast medium, has increased risk of complications.

Question 3

puncture sites

Answer 3

• femoral: retrograde, anterograde, bilateral
• brachial
• radial
• popliteal

Question 4

possible complications

Answer 4

1. at the puncture site:
   - bleeding, hematoma
   - pseudoaneurysm
   - AV fistula
   - occlusion
2. embolisation
   - selective carotid angiography: 0.1-0.3% risk for stroke
   - non-selective arch aortography: 0% risk
3. dissection

Question 5

closure devices

Answer 5

used for large puncture sites, especially in highly anticoagulated patients.
- Angio-Seal: absorbable collagen sponge, absorbable polymer anchor connected by an absorbable self-tightening suture.

Question 6

arterial interventions

Answer 6

• percutaneous transluminal angioplasty (PTA), stent implantation
• stent-grafts (TAA and AAA) & covered stents
• thrombolysis, aspiration, thrombectomy devices
• embolisation (tumors, AVM, fibroif (UFE), bronchial artery, GI bleeding, bleeding from tumors, trauma, iatrogenic)
• dialysis fistulae managements (declotting, PTA)

Question 7

percutaneous transluminal angioplasty (PTA)

Answer 7

• lower limb, subclavian, renal, aorta, mesenteric, carotid bifurcation, proximal CCA, innominate, coronary
• special balloons: cutting balloon, cryotherapy
• stent types: balloon-mounted, selfexoandable, drug-eluting

Question 8

venous procedures/interventions

Answer 8

• PTA/stent, TIPS
• varicocele embolisation
• radiofrequency or laser ablation of varicose veins
• IVC filter placement and retrieval
• venous access, chronic venous lines (Hickman line)
• foreign body retrieval
• venous sampling

Question 9

what to do before getting access

Answer 9

• examination of the patient
• patient history, previous interventions, operations
• pulse palpation
• laboratory values
• risk/benefit ratio
• consenting the patient
• plan the whole procedure

Question 10

advantages of interventional radiological procedures over surgery

Answer 10

1. local anesthetics - no complications from general anesthesia
   - no surgical dissections (no wound infections, no nerve injury, no suture insufficiency)
   - small amount of blood loss
   - minor burden for the patient / can be performed on severely ill patients
   - following unsuccessful intervention, surgery is still an option
   - can be repeated numerous times

Question 11

disadvantages of interventional radiological procedures over surgery

Answer 11

• not all surgical procedures can be substituted by an interventional procedure
• interventional radiological procedures are also not free of complication

Question 12

stent types

Answer 12

1. balloon mounted:
   - premounted, stainless steel
   - easy positioning
   - rigid (external compression)
   - not comformable for different diameters (eg. carotid bifurcation)
2. self-expandable - nitinol (nickel-titanium alloy):
   - continuous expanding force
   - conforms to different diameters
   - positioning is less precise
   - shortening - larger diameter, decreased length

Question 13

PAD - peripheral arterial disease

Answer 13

• largest component to the workload
• most patients are chronic:
  a. asymptomatic
  b. intermittent claudication (IC)
  c. critical limb ischemia (CLI)

Question 14

non-surgical treatment for PAD

Answer 14

1. IC patients:
   - exercise
   - smoking cessation
   - aspirin
   - clopidogrel
2. CLI patients:
   - antiplatelet therapy
   - prostanoids (PGE1, Iloprost)

Question 15

percutaneous transluminal renal angioplasty (PTRA) - indications

Answer 15

• severe hypertension resistant to full medical treatment
• ACE-inhibitor induced uraemia
• deteriorating renal function
• flush pulmonary edema
• acute renal failure with a good sized kidney
• severe stenosis in a single functioning kidney

Question 16

carotid artery stenting CAS - indications

Answer 16

• used to decrease the risk of ipsilateral embolic stroke *
• symptomatic patients within 6 months; patients with symptoms within 4 weeks benefit most ( >70% diameter stenosis)
  possible symptoms: hemisymptoms, amaurosis fugax, aphasia
• periprocedure complication rate should be < 3%, otherwise the pt does not benefit from CAS/CEA (carotid endarterectomy)

Question 17

CAS - relative indications

Answer 17

• asymptomatic, with:
• > 90% diameter stenosis
• > 80% stenosis and ipsilateral silent ischemia on CT
• rapid progression of carotid stenosis
• > 90% diameter stenosis and contralateral occlusion
• periprocedure complication rate should be < 3%, otherwise the pt does not benefit

Question 18

stent graft - covered stent: indications

Answer 18

• aneurysms
• traumatic lesions
• to decrease the risk of re-stenosis
• to decrease the risk of distal embolisation

Question 19

abdominal aortic aneurysm (AAA)

Answer 19

• focal widening > 3cm
• normal size of abdominal aorta (> 50 y.o.): ~ 2 cm
• prevalence: increases with age, greater with atherosclerotic disease
• male predominance
• whites:blacks = 3:1
• risk factors: male, age > 75, white, prior vascular disease, HTN, smoking, family history, hypercholesterolemia
• 30% asymptomatic
• 26% abdominal mass
• 37% abdominal pain
• location: 91-95% infrarenal with extension into iliac arteries (66-70%)

Question 20

intraarterial thrombolytic therapy

Answer 20

• Intravascular administration of thrombolytic agents -> for pulmonary embolism
• Thrombolysis by means of selective catheter infusion -> for vascular occlusion
• also for: treatment of thrombus and/or thrombosis in the coronary arteries, peripheral vascular and visceral arteries, dialysis grafts, veins, and IV catheters.

Question 21

thrombolysis

Answer 21

1) Urokinase: 2-chain Ser protease, that contains 411 am. ac/s. Like streptokinase, it lacks fibrin specificity and induces a systemic lytic state. Urokinase is typically given with full heparinisation (aPTT 1.5-2 times control values). Titration o the dose of heparin is often difficult to achieve.
2) recombinant human tissue-type plasminogen activator (tPA): Ser protease that is produced by recombinant DNA technology. Chemically identical to human endogenous tPA. Acts by stimulating fibrinolysis of blood thrombi.

Question 22

indications of thrombolysis

Answer 22

• acute and chronic vascular occlusion
• thromboembolus
• native bypass graft occlusions
• acute lower-limb ischemia -> prevention of amputation

Question 23

contraindications of thrombolysis

Answer 23

• intracranial or GI hemorrhage in patient history

- any operation within 6 weeks

Question 24

relative contraindications of thrombolysis

Answer 24

• coagulopathy
• gastric/duodenal ulcer
• liver disease, portal HTN
• extreme HTN
• gravidity
• ICU care not possible
• lack of cooperation of the patient

Question 25

complications of thrombolysis

Answer 25

bleeding - may be fatal - GI: 5-10% - puncture site: 12-17% - hemorrhagic stroke: 1-3%

Question 26

materials used for embolisation

Answer 26

- coils - PVA particles - lipiodol - alcohol - tissue glue (cyanoacrilate) - thrombin (for pesudoaneurysms)

Question 27

uterine fibroid embolisation (UFE)

Answer 27

Indications: symptomatic leiomyoma "ideal" candidate for UFE: - symptomatic premenopausal women - single or multifibroid uterus - in whom surgery is indicated - who does not desire to preserve fertility - who prefers minimal invasive treatment

Question 28

venous access - methods

Answer 28

- chronic infusion catheters - peripherally inserted central infusion catheters (PICC) - ports - alternative vascular access techniques

Question 29

chronic infusion catheters

Answer 29

a) temporary (non-tunneled): - no precise definition for time - planned duration more than 6 weeks is considered long-term - exit ports in close proximity to the venous puncture site ``` b) long-term (tunneled): Indications: - chemotherapy - long-term nutrition (TPN) - antibiotic treatment - hemodialysis - plasmapheresis ```

Question 30

insertion techniques for venous access / chronic

Answer 30

1) right (or left) IJV: - most common - higher success rate - lower complication rate - US guidance 2) subclavian vein: - infraclavicular or - supraclavicular -> rare, more risky 3) femoral vein: - easiest - highest incidence of complications - infection & thrombosis

Question 31

possible complications of venous access

Answer 31

1) immediate: - PTX - great vessel puncture or perforation - air embolism - catheter malposition 2) delayed: - infection - venous stenosis - fibrin sheath & thrombus formation

Question 32

IVC filter insertion - absolute indications

Answer 32

* DVT: - contraindication for anticoagulation - recurrent thromboembolic disease, despite anticoagulation therapy - significant complication of anticoagulation therapy - inability to achieve adequate anticoagulation (despite patient compliance)