5- Stents for coronary arteries

Question 1

What are stents ?

Answer 1

Tube shaped fames that open hollow vessels (arteries) and delay or prevent restenosis (narrowed bood vessel)

Question 2

What is angina pectoris ?

Answer 2

chest pain due to ischemia of the heart muscle due to blocker or narrowed blood vessel.

Question 3

What are the two types of angina pectoris ?

Answer 3

Stable and unstable anginas.

Question 4

define stable angina and unstable angina

Answer 4

1- stable : myocardial ischemia, activity caused, chest discomfort
2- unstable : changes or worsens, unpredictable (rest ?) , may herald heart attack.

Question 5

What is the main cause of angina pectoris ?

Answer 5

Artherosclerosis.

Question 6

what is artherosclerosis ?

Answer 6

formation of plaques in artheries: composed of macrophages and cholesthrol crystals.

Question 7

What are the three risk factors of artherosclerosis ?

Answer 7

Smoking, hypertension and hyperlipidemia.

Question 8

How can symptoms like angina pectoris can be treated ?

Answer 8

Lifestyle change, medication or surgical etervention.

Question 9

What are the two types of intervention for angina pertoris ? (surgical )

Answer 9

Bypass surgery (major invasive) and balloon angioplasy with or without stents (minor invasive)

Question 10

When has emerge the first type of stents

Answer 10

1986

Question 11

describe the two main way of expanding stents

Answer 11

balloon expanded or self expanded.

Question 12

Describe how to implant stents (7steps)

Answer 12

access via arm atery or groin 
stent is pushed forward the coronary artery
angiography  to control catheter
stent insertion via catheter
balloon catheter is inflated 
stent is expanded 
catheter, wire and ballon removed

Question 13

Site 4 requirements for ideal stents.

Answer 13

flexible
compressible
expandale
manufacturable
durable
polymerAdhesion
Mri compatible
radiopaque
biocompatible
corrosion resistance
surface finish
strong

Question 14

Describle the main step for stents fabrication

Answer 14

Laser cutting
Etching
sputtering (pulverisation)

then welding/bending
thenpolishing

Question 15

Site the 6 groups of stents

Answer 15

Bare metal stents
Drug eluting s
bioresorbable
bioengineered
dual therapy stents
electronic staining stents

Question 16

What are bare stents and site their limit.

Answer 16

Made of stainless steel or CoCr alloy.
just keep the vessel open.

Risk of thrombosis and restenosis

Question 17

hat are drug eluding stents ?

Answer 17

metal stents coated with drug eluting polymer

Question 18

what are the three layer of polymer ?

Answer 18

1 for adhesion , 2 for the drug and 3 for slowing down the release of the drug.

Question 19

What are bioresorbable stets ?

Answer 19

Stent is made of POLYMER POLYLECTIC ACID and woated with polymer.

Question 20

How long a bioresorbable stents stays ?

Answer 20

2y

Question 21

What are bioengineered stents ?

Answer 21

coated with antibodies that attracts endothelial progenitors cells. it speeds up the natural healing.

Question 22

What are dual therapy stents ?

Answer 22

Inside coated with antibodies (toward the blood)

outside coated with drug blocking inflammation.