Orbital and Rotational Atherectomy,Cutting and Scoring BalloonAngioplasty, and Laser

Question 1

What is the Rotablator system?

Answer 1

An over the wire system with a nickel-plated, diamond-coated brass burr driven by compressed gas, achieving speeds up to 200,000 rpm.

The burr creates microparticulate debris when in contact with inelastic tissue.

Question 2

What are the sizes of diamond chips on the Rotablator burr?

Answer 2

20- to 30-μm-sized diamond chips located only on the front half of the burr.

The burr is olive-shaped.

Question 3

What is the primary use of the Rotablator in the present era?

Answer 3

To treat complex coronary artery lesions including lesions >20 mm, calcified lesions, and ostial and bifurcation disease.

Its use has declined with the advent of drug-eluting stents.

Question 4

What were the findings of the STRATAS and DART trials regarding rotational atherectomy?

Answer 4

Neither trial found a lower incidence of restenosis with rotational atherectomy compared to balloon angioplasty.

STRATAS trial (2001) and DART trial (2003) examined restenosis rates in randomized fashion.

Question 5

What is the indication for using rotational atherectomy according to the 2011 ACC/AHA guidelines?

Answer 5

Indicated for use in nondilatable lesions as debulking prior to stent placement.

Further attempts at predilation would be unhelpful.

Question 6

What is the excimer laser coronary atherectomy system (ELCA)?

Answer 6

A system consisting of a multifiber catheter and a CVX-300 console that emits light at ultraviolet wavelengths of 308 nm.

It vaporizes plaque using photochemical, photomechanical, and photothermal effects.

Question 7

What is the role of the AngioSculpt scoring balloon?

Answer 7

A balloon catheter with three rectangular nitinol scoring wires wrapped in a helical fashion, allowing greater focal force compared to standard balloons.

It minimizes slippage in restenotic lesions.

Question 8

What is wire bias in the context of rotational atherectomy?

Answer 8

The position of the rotational atherectomy wire in an eccentric position within the coronary vessel.

It can facilitate effectiveness if positioned against the lesion.

Question 9

What is the mechanism of action of orbital atherectomy?

Answer 9

It utilizes centrifugal force to press a diamond-coated crown against the lesion, resulting in differential sanding.

It is an over the wire system with a single eccentrically mounted crown.

Question 10

What are the potential complications associated with laser angioplasty?

Answer 10

Increased incidence of perforation and local complications due to scattering of laser light by contrast.

Coaxial guidewire positioning is important for success.

Question 11

What is the primary indication for orbital atherectomy?

Answer 11

Treatment of heavily calcified lesions.

It is particularly suited for lesion preparation prior to stenting.

Question 12

True or False: Rotational atherectomy reduces restenosis rates before the use of drug-eluting stents.

Answer 12

False.

The ROTAXUS trial indicated similar late lumen loss with or without rotational atherectomy.

Question 13

What is the difference in particle size generated by orbital atherectomy compared to rotational atherectomy?

Answer 13

Particles generated during orbital atherectomy are <2 μm, while those from rotational atherectomy are 5 to 12 μm.

Smaller particles are believed to be less likely to cause microvascular plugging.

Question 14

Fill in the blank: The Flextome Cutting Balloon Device features _______ longitudinally fixed to a balloon.

Answer 14

atherotomes.

Atherotomes create controlled longitudinal incisions when deployed.

Question 15

What is the maximum pressure that the AngioSculpt scoring balloon can be expanded to?

Answer 15

20 atm.

This allows greater force to be applied compared to standard balloon angioplasty.

Question 16

What is a clinical contraindication for using a cutting balloon distal to a recently implanted stent?

Answer 16

Fear of having the atherotomes entangled with the stent on withdrawal.

This could lead to complications during the procedure.

Question 17

What is the primary indication for the use of orbital atherectomy?

Answer 17

Treatment of heavily calcified lesions

Orbital atherectomy is specifically designed for addressing severe calcification in coronary arteries.

Question 18

How do the particles generated by orbital atherectomy compare to those generated by rotational atherectomy in terms of size?

Answer 18

Orbital atherectomy generates particles smaller than 2 μm, while rotational atherectomy generates particles between 5 to 12 μm

Smaller particles from orbital atherectomy are believed to have different biological effects.

Question 19

What is a contraindication for the use of orbital atherectomy?

Answer 19

Presence of angiographically visible thrombus

This condition increases the risk of distal embolization and potential slow or no reflow.

Question 20

What strategies can prevent slow flow during rotational atherectomy?

Answer 20

Strategies include:
* Lower burr speeds
* Short runs <45 to 60 seconds
* Applying Rotaglide lubricant
* Aggressive vasodilation with nitroglycerin or nitroprusside
* Maintenance of blood pressure with short acting pressors

These strategies help mitigate the risk of microvascular obstruction.

Question 21

True or False: Routine use of rotational atherectomy has been shown to improve outcomes for de novo or restenotic lesions.

Answer 21

False

It has a class III indication for this purpose, indicating it is not recommended.

Question 22

What complication may arise from excessive forward pressure on the burr during ablation?

Answer 22

Type III, free-flowing perforation at the lesion site

This can occur if ablation penetrates too deeply into the vessel wall.

Question 23

What is recommended regarding the positioning of the guidewire for orbital atherectomy?

Answer 23

The guidewire should be positioned at least 10 cm distal to the lesion

This ensures proper navigation and effectiveness of the procedure.

Question 24

Fill in the blank: Orbital atherectomy is delivered over a _______ guidewire.

Answer 24

0.012-in. guidewire

This is specific to orbital atherectomy, while rotational atherectomy uses a 0.009-in. guidewire.

Question 25

What is a common reason for failure to obtain stent expansion despite high-pressure balloon angioplasty?

Answer 25

Calcific constraint of the stent

Rotational atherectomy may be necessary to address the calcification before stent expansion can occur.

Question 26

What are the results of the ORBIT I trial regarding device success?

Answer 26

Device success was 98%

The ORBIT I trial was a two-center prospective nonrandomized feasibility study.

Question 27

What percentage of patients experienced major adverse events in the ORBIT I trial?

Answer 27

4% in-hospital, 6% at 30 days, and 8% at 6 months

These figures reflect the safety profile of orbital atherectomy.

Question 28

What was the rate of slow flow and no reflow after orbital atherectomy in the ORBIT II trial?

Answer 28

Less than 1%

This demonstrates the effectiveness of orbital atherectomy in minimizing these complications.

Question 29

What alternative treatment might be considered if rotational or orbital atherectomy fails?

Answer 29

CABG (Coronary Artery Bypass Grafting)

This is a surgical option when other interventions are unsuccessful.