This document discusses various debulking devices used in coronary interventions including cutting balloons, scoring balloons, rotational atherectomy, orbital atherectomy, and laser atherectomy. It provides details on the mechanisms of action, sizes, indications, complications and how to manage complications for each device. The goal of these debulking devices is to remove rigid plaque to facilitate balloon dilatation and stent implantation while minimizing vessel wall injury.

1. Debulking Devices

2. Cutting Balloon
• Flextome cutting balloon
• Made up of 3 (2-3.25mm) to 4 (3.5-4mm)
microsurgical blades mounded longitudinally
on a non-compliant nylon balloon.
• Size – Diameter- 2.0 to 4.0mm with 0.25mm
increment.
Length- 6, 10 & 15mm

3. • Mechanism- longitudinal incision in the
plaque that allows controlled dilatation at
lower pressure with less vessel wall injury

6. Scoring Balloon
• AngioSculpt scoring balloon
• Consist of 3 rectangular spiral nitinol scoring
elements wrapped on a semi-compliant nylon
balloon
• Size – Diameter- 2.0 to 5.0mm
Length- 10, 15 & 20mm
Inflating pressure – wide 2 to 18 atm

7. • Mechanism- During dilatation, rectangular
scoring elements lock the device in place &
prevent watermelon seeding.
Dilatation force is concentrated over a small area
of the scoring elements & exert a force equal to
15-25 times that of conventional balloon leading
to large lumen expansion with limited vessel
wall injury.
• Advantage
– Smaller crossing profile (2.7Fr)
– Enhanced flexibility facilitates delivery of catheter
in tortuous anatomies.

8. Complication-
– Coronary spasm-
-Not uncommon
-I/C NTG
– Coronary dissection –
-10% cases
-mainly minor/ non-flow limiting
-Stent implantation
- Perforations
- Rare
- M/C- Balloon oversizing ( Balloon:artery ratio>1.1)
- T/T- reversal of anticoagulation, prolonged balloon
inflation, covered stent implantation

9. - Late aneurysm
- Reported in perforation managed with prolonged
balloon inflation.
- Device entrapments
- During t/t of ISR, when wire passes through an
unopposed stent strut

10. • Various maneuvers to remove the entrapped
device:-
– Advancing the device forward & rotating it to
unhook the trapped strut or atherotome.
– Inflating second balloon alongside the entrapped
device
– Deep seating of the guiding catheter & controlled
retraction of the device.
– Surgical removal, if all unsuccessful

11. Rotational atherectomy
• Consist of: Cylinder, Console, advancer, Foot
pedal
• Burr- elliptical shaped with 2000-3000
microscopic diamond crystal on distal edge.
Proximal end- smooth

13. Mechanism-
• Differential cutting- rapidly rotating burr
selectively ablates rigid inelastic tissue
components (calcium & fibrous tissue) while the
elastic normal vessel wall components deflect
away from cutting edge
• Orthogonal displacement of friction- high speed
rotation changes the longitudinal friction vector
b/w the wire & burr to circumferential direction
which facilitates burr advancements through
tortuous anatomies
• Generated particle size- 5 micron, cleared by
reticuloendothelial system.

14. Indications for Use
• Calcified Vessels
• Failure to Dilate
• In-stent restenosis
– Multiple stent layers
– Jailed branches
• Ostial lesions (aorto-ostial lesions)
• Bifurcation lesions
• Long lesion <25mm
Rotational Atherectomy

15. Rotational Athectomy
• Occlusions not passable with guide wire
• Last remaining vessel
• Severe LV dysfunction
• Saphenous vein grafts
• Angiographic thrombus pre-treatment
• Significant dissection at treatment site
Contraindications

16. Precaution
• EF<30%
• Angulated lesions (≥45°)
• TPI- lesion of RCA, Dominant LCX, Proximal
LAD
• Should only be carried out in hospital where
emergency CABG is available.

17. Complication
1) Slow flow/ no reflow
0.5-2%
cause:-
• Large burr & higher speed
• Lesion that are thrombotic/ contain large amount of fatty atheroma
• Shorter time intervals b/w ablation runs
Prevention
-Slow speed rotational ablation (RPM 140,000-160,000)
-Minimal deceleration during ablation runs
-Multiple short runs of 30 seconds or less
-Rest period b/w runs
T/t-
-retraction of burr
-Optimization of perfusion pressure
-I/C vasodilators- NTG, CCB, adenosine, nicorandil
-IABP

18. 2) Perforation
- 0.05-1%
-Oversized burr
-Angulated lesions.
3) Burr entrapment
Burr crossing the lesion without adequate ablation.
T/T
-Gentle controlled traction with guide catheter
deep intubation or mother & child catheter
-Balloon inflation besides the burr
-Snare assisted traction
-Surgical removal

19. 4) Bradycardia/ AV block
RCA/ dominant LCX/ Proximal LAD
Large burr>2.25mm
Mechanism-
- microparticle interfering with vessels perfusing
AV node
-vibrations/ heat of burr causing reflex
bradycardia.
Prevention
- limiting ablation time <15-20seconds
-pretreatment with atropine
-Deactivate burr when slowing of heart rate is
noted
- asking the patient to cough.

20. Orbital atherectomy
• Diamond back 360° coronary orbital
atherectomy system.
• Ablating component- diamond encrusted
crown.
• Mechanism- differential sanding & centrifugal
force

21. Orbital atherectomy Rotational atherectomy
Eccentric crown orbits over guide wire at
two different speeds (80,000 & 120,000)
Single speeds
Selectively ablates rigid plaque
components while elastic tissue flexes
away from the crown.
- same-
Crown has diamonds chip both front &
back that enables ablation in both
antegrade & retrograde direction & hence
decrease risk of crown entrapment
Burr has diamond chip only distal, not
proximal, hence risk of crown entrapment
Paticle size generated is 2 micron & hence
less risk of slow/ no reflow
5 micron, more risk of slow/ noflow
Orbital motion allows continous flow of
blood, saline & debris which reduces the
potential ischemia, heat generation &
consequent thermal injury & restenosis.

22. • In one study, orbital atherectomy was a/w
deeper dissections, improved stent expansion
& lower incidence of stent strut
malapposition.

23. Laser atherectomy
• CVX-300 cardiovascular excimer laser system.
• Consist of console, laser catheter & foot pedal.
• Laser catheter uses Xenon chloride to generate
pulse gas laser.
• Sizes- 0.9, 1.4, 1.7 & 2.0mm
– 0.9mm – 5F guiding catheter
– 1.4 & 1.7mm- 7F guiding catheter
– 2.0mm-8F guiding catheter

24. • Mechanism- XeCl emit light rays in UV
spectrum.
• Causes tissue removal by photoablation.
• Photoablation occur in 3 stages:-
– Photochemical- UV light absorb by tissue & cause
breakdown of carbon-carbon molecular bands
– Photothermal- high frequency molecular vibration
result in cellular breakdown & formation of vapor
bubbles
– Photomechanical- vapor bubbles expand & implode to
cause further tissue distruption