ROTABLATION DR. MAHENDRA

CARDIOLOGY,JIPMER

INTRODUCTION• RA technique developed by David Auth in the early 1980s. • designed to work on the principle of differential cutting.• incomplete stent expansion is a well-known predisposing factor for further ISR

and thrombosis.• lesion preparation using RA prior to stent deployment in balloon heavily calcified

undilatable lesion is mandatory.

Mechanism of Percutaneous Translminal Rotational Atherectomy (PTRA)• operates on the principle of "differential cutting“. • hard, fibro calcific plaque ablated by a rotating burr while softer tissue in the

treated coronary segment deflects away from the device and remains relatively unaltered.

• Plaque is ablated and pulverized into particles generally < 10 to 15 microgm in diameter that can uptake by the reticuloendothelial system.

Device Specifics• 1. Rotalink® burr catheter-• elliptical, nickel-coated brass burr attached to a hollow flexible 4.3F drive shaft,

which is encased in a Teflon sheath.

• sheath protects the artery proximal to the lesion from the rotating drive shaft• allows flush solution to be pumped to lubricate the drive shaft and burr. • ablative distal surface is embedded with 20 micro. diamond chips, with 5 micro.

protruding from the surface.• Proximal nonablative surface of the burr is smooth. • back end of the Rotalink burr catheter is connected to a Rotalink® advancer,

which allows the operator to extend and retract the burr within the vessel. • delivers air or nitrogen through a pneumatic hose to the turbine housed within

the Rotalink advancer to spin the drive shaft and the burr.

2. console-

3.Rota wire burr can be advanced over the 0.009-inch section, but its

forward movement is delimited by the wider wire tip . RotaWire™ guidewires have no lubricious coating, no shaping ribbon, and are

easily kinked.

Technique• Patients are pretreated with aspirin and possibly a calcium channel blocker to

counteract PTRA-induced vasospasm. • glycoprotein (GP) IIb/IIIA receptor antagonists have shown benefit in limiting

speed dependent platelet activation.• Rotaglide™ , a lipid emulsion, can be added to the flush solution to reduce

friction, limit heat generation, and facilitate device deliverability.

Influence of a platelet GPiib/iiia receptor antagonist on myocardial hypoperfusion during rotational atherectomy as assessed by myocardial Tc-

99m sestamibi scintigraphy. ] Am Call Cardio/ 1 9 9 9 ; 3 3 : 998-1004.

• Over time, effluent heat increases due to friction in the system• Increased heat in artery is associated with h platelet aggregation• Rotaglide emulsion minimizes heat buildup

• Baseline temperature is low compared to standard saline flush• Baseline temperature remains stable

0.00 1.00 2.00 3.00 40

45

50

55

60

65Temp with saline Temp with RotaGlide

Time (min)

Tem

p (C

)

Rotaglide LubricantHeat Generation

• temporary pacing wire can be used in PTRA of the RCA or dominant LCX due to the risk of profound bradycardia.

• adenosine release with red cell fragmentation lead to bradycardia• guiding catheter with a gentle curve and an inner diameter at least 0.004 inch

longer than the anticipated largest burr diameter is recommended.

• Rota Wire floppy is chosen in order to minimize guidewire bias• phenomenon observed when a stiff guidewire straightens a curved vessel

segment and causes deeper cuts or dissection as the burr is forced against the tautly stretched lesser curvature of the vessel.

• floppy guidewire may fail to adequately constrain burr's passage around tight bends , leading t o uncontrolled cutting on the greater curvature of the vessel.

• final burr-to-artery ratio should generally not exceed 0 . 7 (e.g. , 2 . 1 5-mm burr in a 3 .0-mm vessel).

• preprocedural "DRAW "checklist, consisting of the following steps-• “drip"-Adequate flow of the pressurized heparinized flush through the Teflon

sheath is visualized. • "Rotation“- holds the catheter carefully so that the burr tip is not in contact with

the sterile drapes• the system should be tested by depressing the foot pedal and having an assistant

adjust the turbine pressure to achieve the desired burr speed. • "Advancer"-Test whether the advancer moves the burr freely. • "Wire"-Ensure that the wire clip is in place on the wire and test whether the

brake locks the wire in place during rotation.

• Once the burr has been advanced to 1 to 2 cm proximal to the target lesion, the advancer lever should be unlocked and pulled gently back to near its proximal limit as the entire catheter is withdrawn gently by 1 or 2 mm.

• Under fluoroscopy, the burr is then activated by the foot pedal and adjusted to the desired "platform" speed (generally 1 6 0 ,000 to 1 80 ,000 rpm for burrs <2 mm, 140,000 to 160 ,000 rpm for burrs > 2 . 0 mm) before engaging the lesion.

• essential to avoid speed drops of > 5 ,000 rpm during advancement.• compressed air or nitrogen source to the console is confirmed to have a pressure

of at least 500 PSI.

• prefer advancing with a "pecking" motion in which brief (1 to 3 seconds) periods of plaque contact are alternated with longer (3 to 5 seconds) periods of reperfusion provided by pulling the burr back from the plaque.

• While removing facefoot pedal is then used to activate the lower speed "dynaglide" mode, and the burr is removed while depressing brake release button.

Clinical Results

Coronary atherectomy recommendation• Class IIa• 1.rotational atherectomy is reasonable for fibrotic or heavily calcified lesion that

might not be crossed by a balloon catheter or adequately dilated before stent implantation.(level of evidence C)

• Class III• 1.should not be performed routinely for denovo lesion or ISR (level of evidence

C).

• Occlusions not passable with guide wire.

• Last remaining vessel.

• Severe LV dysfunction.

• Saphenous vein grafts.

• Angiographic thrombus.

• Significant dissection at treatment site.

Contraindications

Complications • Bradycardia and Atrioventricular blocks

• Slow Flow Or No Reflow And Vasospasm

• Dissection

• Perforation

• Side branch occlusion

• hypotension

Rotabalator System Failure

•Burr Entrapment .•Burr Detachment.•Rota Guide Wire Fracture.

Management of Bradycardia And Atrioventricular Block

• Prevention• Limiting ablation times (<15-20sec)• Pretreatment with Atropine• Deactivate the burr when slowing of heart rate is noted• Ask the pt to cough.

Slow flow and No Reflow • most challenging adverse sequelae.

• observed in 5% pts

• Mechanism-

Prevention of slow and no flow • Deploying burr in step method to minimize the effect of plaque burden for given burr size.

• Gentle advancement and intermittent retraction helps in preventing

drop in rpm <5000

significant generation of heat

reestablishment of flow for particle clearance

• Limiting the ablation time to 15-30 seconds.

• Increasing the time between the ablations

• Slower speed (140,000 rpm) associated with lower platelet aggregation , so beneficial.

• Prior use of GPIIb/IIIa very usefull (abciximab).

Dissection• Incidence 10%• mod to severe angulated lesions dissections are more commonly

noted, burr dose not follow the natural course of the vessel.• Guide wire vector would cause the orientation of the burr to be out of

planes, and result in tangential ablation with potential dissection• placement of the guide wire plays paramount role in establishing the

cutting vector of the device .

• Goal is to set the optimal central vector for burring.

• Because increased tension (rigidity) on the wire can cause psudolesions in the

vessel and increased stiffness of the vessel can cause tension on the wire and it

will affect the advancement of the burr.

• Angiogram should be performed after the placement of the wire to assess the

interaction between the two.

Guide wire “unfavorable” bias can increases the chances of dissection and burring of the normal tissue

HOW TO MINIMIZE THE “BIAS”• Retracting the Rota guide wire to proximal position may improve co axial

alignment at the lesion site and prevent psudolesions formation distally

Perforations• Incidence 0.7% reported from multicenter registry.

• Mechanism:- Oversize burr OR Tangentially oriented burr due to trajectory of guide wire .

• More common in severely angulated lesions,

• This can occur even in elastic vessels , since the strain or penetration of guide wire in to the wall will exceed the elasticity of vessel wall and ablation of tissue will occur and potential perforation .

Management

• minimize guide wire bias by proper co- axial guide catheter and guide wire

placement

• Relaxation of the guide wire is important.

• Undersize the burrs in severely angulated lesions especially those are

straightened with guide wire or showing psudolesions.

• “pecking” technique should be used to avoid excessive cutting.

Rotablator System Failure• Despite mechanical complexity of the system ,device failure is a rare

event.• These are burr entrapment burr detachment guide wire fracture

Burr Entrapment • 1.Can occur if a burr slips across the lesion without the burring

(coefficient of friction is less at the high speed than at the rest ).

• Ledge of the calcium behind the elliptical burr causes “Kokesi” effect.

• 2.get entrapped in the tortuous segment of the lesion

And vasospasm.

Management Of Entrapped Burr• Vigorous use of vasodilators • Pulling back rotablator system manually• Sometime it will be successful with manual traction with on dynaglide or off

dynaglide rotation

conclusion• Require skilled operator.• RA increase the cost and duration of procedure.• Judiciously used in indicated case and well aware of contraindication is necessary for avoiding

complication n achieving good results.• Used in heavily calcified complex PCI for appropriate stent expansion.• Slow flow n no reflow is frequently seen complication.• Life threatening complication is also not uncommon. • Beyond immediate procedural success, data have not shown consistent long-term benefit of

lesion modification by RA for restenosis and MACE.• more recent series, RA use has fallen to 3% to 5% in select high-volume centers and <1% in

others.• IVUS or OCT may prove useful in identifying features of plaque morphology predictive of benefit

Thank you