Ch 04 - Basics of intervention

Question 1

General rule for oversizing stents?

Answer 1

5-10% greater than normal lumen

Self expanding stents 10-20% larger

Question 2

Acceptable post-invervention pressure gradients for:

1. Arterial stenosis
2. Venous stenosis
3. TIPS

Answer 2

1. Artery - <10 mmHg
2. Vein - <5 mmHg
3. TIPS - <12 mmHg

Question 3

Diff between compliant and noncompliant balloons?

Answer 3

Compliant balloons continue to enlarge until they burst. Used for TBO and thrombectomy

Noncompliants have nominal pressure, and enlarge only slightly beyond that

Question 4

Noncompliant balloons: when to use low pressure vs high pressure

Answer 4

Low pressure: artery

High pressure: vein

Question 5

How much pressure can you generate by hand with 10 cc syringe?

Answer 5

10-12 atm, generally enough for most arterial lesions

Question 6

Tips for hand insufflation?

Answer 6

Inflate with 10 cc syringe, deflate with 20 cc syringe

Dilute contrast 1 to 3

Question 7

Management of vessel rupture after angioplasty

Answer 7

Maintain wire access across lesion!

If no wire access, TBO proximally

Question 8

What is cholesterol embolization?

Answer 8

Cholesterol crystals embolize during arterial intervention causing distal inflammatory/ischemic response that is angiographically occult

Question 9

Difference btw open and closed cell stents

Answer 9

Open cell: most flexible but can ‘shingle’ or ‘fishscale’ when deployed over tight curves

Question 10

What is reperfusion syndrome?

Answer 10

Severe metabolic disturbances following revascularization in irreversibly ischemic tissue

Question 11

Contraindications to thrombolysis?

Answer 11

1. Irreversible ischemia
2. Active bleeding
3. Recent surgery
4. Craniotomy within 2 mo
5. Brain tumor
6. Stroke within 6 mo
7. History of spontaneous ICH
8. Uncooperative or demented patient

Question 12

Technique for pulse-spray thrombolysis:

Answer 12

tPA: 2-10 mg in 10 cc (inject 0.5 cc every 30-90 sec)