“Rotational Atherectomy” Complications And Management

DR NILESH TAWADEJASLOK HOSPITAL MUMBAI

INTRODUCTION

• RA is associated with complications similar to other percutaneous procedures as well as unique to this device .

• Entire catheterization staff should have a thorough understanding of these complications so that appropriate management can be expedited.

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.•Burr Stalling.•Rota Guide Wire Fracture.

Bradycardia And Atrioventricular Block

• Incidence : more common with RCA lesions > dominant left circumflex A > can occur with proximal LAD when large burrs (2.25mm) are used .

• It can occur instantly after activating the burr or can follow slowing trend of the burr.

Bradycardia And Atrioventricular Block

• Mechanism of bradycardia or AVB.

- Unclear

- Various Theories

• micro particles interfering with vessels per fusing

AV node

• vibrations and heat of burr causing reflex

bradycardia.

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

Management of Bradycardia And Atrioventricular Block

• Some operators advances pacemaker only into

the IVC and place it into the RV when needed.

• Present recommendations are the placement of

temp pacemaker in pts under going treatment of

RCA ,Dominant LCX, proximal LAD giving

collaterals to RCA .

Management of Bradycardia And Atrioventricular Block

• Pacemaker usually set at 50bpm .

• It should be tested prior to the procedure for assessment of ventricular capture.

• Blood pressure may drop from during pacing so prior proper hydration is necessary.

• Since the coronary blood flow is compromise during pacing , limiting run times during pacing is recommended .

Slow flow and No Reflow

• It is most challenging adverse sequelae.

• Observed in 5% pt undergoing treatment with rotablator.

• Slow flow : diminution of flow by 1 -2 TIMI grades from base line.

• No Reflow : Cessation of flow into the distal vessel which is treated or back and forth movement contrast without clearing from the vessel.

Mechanism Of Slow Flow Or No Flow

• Excessive plaque burden and long lesion

• Long ablation time

• Vasospasm

• Platelet activation

• Micoparticulate aggregation

• Treatment of the vessel in the previously

infarcted segment

Slow Flow And No Reflow Management

• “No flow” has more deleterious impact

• Once observed no further burring should be done.

• Intra coronary NTG , VERAPAMI, ADENOSINE should be given adequately .

• Blood perfusion : forcefully re injecting it . (mechanism:- accelerate particle clearance and perfuse the vessel)

• Maintain adequate perfusion pressure either with Hydration or Vasopressors or IABP.

Slow flow and No Reflow • Ability to differentiate slow flow and no reflow from abrupt

closure or flow limiting dissection is important .

• Because they distinctly different treatments

• Abrupt closure from severe dissection or flap should be

treated with prolonged balloon inflations or stenting.

• And prolonged balloon inflations will not improve situation in

case of slow or no flow

• Sometimes severe vasospasm is difficult to differentiate from

no flow . Although the treatment is similar.

Slow Flow And No Reflow Management

• Adjunctive PTCA is useful in this situation, this will help to relieve the spasm and balloon may acts like “plunger” to accelerate the passage of blood

• Gp IIb/IIIa inhibitors are very beneficial in this situation.

Management of Bradycardia And Atrioventricular Block

• In summary , the management of slow flow or no reflow requires the integration of several techniques and aggressiveness of the operator as they set up the kind of “vicious cycle”

• Once flow has been re-established the ECG begins to normalize but, It will not return to baseline even if the epicardial vessels are visualized .

• pts chest pain begins to improve but requires time for complete resolution (usually >20 min)

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 and

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%• In cases with mod to severe angulated lesions

dissections are more commonly noted because at angles, 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

• Therefore placement of the guide wire plays paramount role in establishing the cutting vector of the device .

Dissection

• 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 .

How To Minimize The Rota Guide Wire Tension

• Tension on guide wire can be relieved by first relieving the drive shaft tension by retracting it by approximately 1 cm, once the burr has reached proximal to the lesion.

• Visualization under fluoroscopy of the burr retracting indicates tension has been relieved

• This relief of tension also prevents burr from lurching forward after activation and causing trauma.

Special situations

• Another common site prone to dissection is ostium of severely angulated circumflex artery.

• Stiffness of the wire can eccentrically orient the burr and force the burr to preferentially ablate on the inner aspect of the vessel.

• In case of ostial circumflex on a severe bend , attempt to telescope the guide catheter to remove the angle ,

• Amplatz GC can be helpful

• If alignment can not be achieved then undersize the burr for a maximum A:B ratio of 0.5 to 0.6.

• Location of dissection plane usually remains in the calcified plaque which is ablated.

• Dissections can be managed by deploying oversized balloon at low pressure to tack up the tissue and then stenting.

Perforations • Incidence 0.7% reported from multicentre 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

• Therefore the methods to avoid perforation are to 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 .

Side Branch Occlusion• Since the secondary protective wire cannot be used with Rot

ablator system so careful attention should be given.

• In most of the cases it is due to micro particle debris or

vasospasm in contrast to usual PTCA in which it is due to plaque

shift.

• To prevent occlusion, burr can be platformed distal to the take off

of the side branch if possible

• Vasospasm generally responds to vasodilator therapy.

Side Branch Occlusion• If not responded to vasodilators then low pressure

balloon dilatation at the site of spasm is sometimes worthwhile.

• Bifurcation treatment depends on the size of the side branch

• Two approaches are possible 1) ablate both limbs or 2) ablate one and dilate the other

• In case LAD/ Diagonal Bifurcations , large diagonals are ordinarily ablated

• While Smaller diagonals are treated with dilatations

Side Branch Occlusion

• Initiate the burring or pre-dilatation in the limb in which it is technically difficult to place the guide wire provided its “Large” as parent vessel.

• usually with ostial lesions in the side branch can be ablated with undersized burr if they are not dilatable with low pressure dilatations.

Hypotension• In rotablator procedure antecedents of

hypotension episodes can

vasospasm ,

slow and no reflow,

bradycardia and

inadequately hydrated patients

pts on large dose of vasodilators

Management of hypotension

• Coronary blood flow is major determinant of particle clearance.

• Therefore at the starting of the procedure pt should not be hypovolemic and if its ,then procedure should be delayed until fluids are administered.

• If intra procedural hypotension occurs after ablation, infusion of fluids should be done

• and if associated with slow flow or no reflow immediately start vasopressors and placement of IABP will be very helpful.

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

is a rare event.

• Majority of device failure due to use of the device outside the standard operations.

• These are burr entrapment burr detachment burr stalling guide wire fracture

Burr Entrapment • 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.

• It may get entrapped in the

tortuous segment of the lesion

Management Of Entrapped Burr• Vigorous use of vasodilators

Management Of Entrapped Burr

Management Of Entrapped Burr

Management Of Entrapped Burr

Management Of Entrapped Burr

BURR DETACHMENT

• Associated with excessive force applied to remove non spinning burr from tortuous artery.

• To avoid this ,do not use burrs with less than 0.004” clearance for the GC.

• If clearance is less than 0.004” then slow inactivated withdrawal of burr is best method to enter GC.

• while exchanging the burr verify that GC is in co axial position with the artery so burr doesn't get trapped onto tip

BURR DETACHMENT

• If burr detaches from the driveshaft cable, the distal tip of the guide wire is 0.017” , so it will keep the burr from exiting the end of the guide wire.

• So entire guiding catheter and guide wire system can be withdrawn after giving adequate intracoronary vasodilators.

BURR STALLING

• When there is significant resistance to rotation.

• Kinking of the air hose• Over tightening of the “Y” connector • B: A ratio 1.0• Aggressive advancement in tight lesions • Spasm in the platform zone • Operation without saline infusion.

GUIDE WIRE FRACTURE

• Result of excessive rotation of the burr in angulated and tortuous arteries.

• Long ablation time

• Formation of loop of which fractures as operator pulls on the wire to remove the loop.

How to minimize the problem

• Keep the GW out of small branches.

• Reposition the GW frequently during the excessively

long ablations.

• Fasten the wire clip properly.

• Avoid prolapsing the guide wire tip.

• Inject contrast to demonstrate the flow around the

guide wire.

Retrieval Of Fractured Wire

• Fractured guide wire portions can be retrieved with the

different types of SNARES and retrieval BASKETS or

FORCEPS

• If unsuccessful and of no hemodynamic consequences

can be left alone with conservative medical

management.

SUMMARY

• To achieve high success and low complications, cardiologists and technical staff must be

WELL PREPARED to address the complication during the procedure.

• Trained personnel for this procedure should be accessible if problem arises.

• Vasospasm and slow flow and no reflow phenomenon are frequently amenable to

pharmacological intervention

• If clinical status of the pt deteriorate and pt is unresponsive to the therapy then surgical

intervention is anticipated as optimal timing is essential for maximum myocardial salvage.

•THANK YOU