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Coronary artery  perforation is a dreaded complication of PCI. Perforations are the Interventional cardiologists ultimate worry   as they need to  manipulate their  hardware for  long periods in many complex lesions.  Especially  it is a  real threat in chronic total occlusions.

Still , an important fact is ,  many of the coronary perforations are not life threatening ?

How is this possible ?  (Type 1 Ellis has zero mortality Read below)

As the guide wire injures and perforates the cor0nary vessel,  it results in  small puffs of dye extravasating  into peri coronary space .

The coronary artery , which is located   within the  atrioventricular groove  (LAD), or AV groove (LCX, RCA) have  two distinct anatomical relationship with reference to epicardium and pericardial space.

50 % 0f circumference of the coronary artery is  hugged  by the myocardium  another 50% or so is related directly to the pericardial aspect.

Guide wires hitting on the myocardial aspects face a stiff resistance than the pericardial aspect. So , generally the risk of perforating pericardial aspect is more than myocardial aspect

Even if , the coronary artery is punctured on myocardial aspect , no great danger occur as there is no potential space for the blood to drain and further,  the  elastic nature of myocardial muscle plane effectively seals the leak. At the most , mild myocardial staining is noted .

coronary-perforation-2

While ,  perforations  into  the pericardial space  , often threaten with a tamponade. The fact that pericardial space has negative pressure and  the mean  coronary arterial pressure around 40mmhg ,  it is  , all the more likely blood is sucked into the pericardial  space. Of course , very minute  perforations  even into the pericardial space ,  could  be self limited and  benign.

coronary-perforation

What is unrecognised coronary perforation?

Many times , the guidewire goes in a false track in the tissue plane.This is  nothing,  but perforation without hemodynamic implication. Most often , these are the instances of guide wire entering the epicardium.They mimic , false lumen entry , dissections, etc. There are occasion , where false lumen of the  coronary artery were  stented.

What are the  factors which increase risk of perforation ?

perforation-6

 How do you classify coronary perforations ?

perforation-3

*Ellis SG, Ajluni S, Arnold AZ,  Increased coronary perforation in the new device era. Incidence, classification, management, and outcomeCirculation. 1994;90:2725–2730

 

How do you manage coronary perforation?

Simple guide wire induced perforations are less trouble some unless we have crossed it with balloon without realising the fact the wire has entered the pericardial space. So, caution is required and always watch for guide wire tip movement which is often funny looking wihtin false lumens or very freely moving within pericardial space. Anticipate the complication especially so when you do CTOs and venous graft PCI.  Keep one cath lab  tamponade crash  bin  in ready mode before embarking upon a complex PCI

  • Neutralise the heparin action with protamine is the first step
  • Most are self limited, no intervention is required  but requires close observation for next 24 hours.
  • Temporary balloon occlusion may be suffice in many cases
  • Tamponade requires immediate tapping. Small collection without fall in BP can be observed.
  • keep doing the echocardiogram liberally to assess the leak and watch for any new collection.
  • PTFE covered stents if prolonged leak.
  • Emergency surgery may required in few.

2018 update 

This is  nearly 10 years old article. Now, we have gained much experience and hardware utilisation have rapidly expanded. While expertise has minimised this complication , more PCIs in complex lesion subset tend to keep the incidence static , if not higher.(Its around .5% )

Tips to use balloon occlusion during perforation

Perforations which are active and flowing should be immediately occluded with a balloon either at the site of leak or just proximal to it. Doing a proximal occlusion is easier in emergency , as often times its technically difficult to reach the site of leak especially in CTOs where the leaky site is not defined clearly or forward looking (Local balloon inflation across the leaky site is not feasible )

 

How long to occlude , Intermittent /complete, proximal ? or at the site of perforation ? These queries are answered in Ref 4

Reference

1.Largest report (1762 cases) of perforation from British Cardiovascular Intervention  Society Database Circ Cardiovasc Interv. 2016;9:e003449.

2.Al-Lamee R, Ielasi A, Latib A,. Incidence, predictors, management, immediate and long-term outcomes following grade III coronary perforation. JACC Cardiovasc Interv. 2011;4:87–95.

3Xiangfei Wang and Junbo Ge Balloon Occlusion Types in the Treatment of Coronary Perforation during Percutaneous Coronary Intervention   Cardiology Research and Practice Volume 2014, Article ID 784018,

4.A very good review comes from Royal Hospital, Muscat, Sultanate of Oman

 

iFAQs in coronary perforations

1.Does the plane of the coronary artery (Sub epicardial within the fat layers)  determine the likely hood of tamponade ?

While myocardial tissue can resist flow we are not sure about sub-epicardial fat on the pericardial aspect.

2.How common is Intra-cavitory perforation ?

Perforations into chamber is invariably associated with septal branches (PCI to septal branch itself is less common )

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First and foremost is

Avoid the procedure if  not really indicated.A lesion which  has more thrombus load  than a plaque and it is ,  subcritical and not limiting the flow  , PCI may be inappropriate  especially if the ACS is stabilised.

  • Adequate anticoagulation  along with  2b 3a blockers should be used
  • Predilatation should be minimally used or to avoided.Direct stenting preferred.
  • In primary PCI suction devices (Export etc may be useful)
  • Distal protective devices  are  “hyped up devices” rarely useful in an occasional patient with good distal vessel diameter.
  • Pseudo stent approximati(fig 1) may occur. A Layer of thrombus may get plastered between stent and the vessel wall.In the post PCI  phase , with intense anticoagulation and antiplatelet regimen this layer may get dissolved and stent  may lose it’s grip and may dislodge or migrate.Another possibility is the dead space  beneath the stent  becomes a potential site for future  thrombus and ACS.

thrombus-and-pci

Fig 1

  • To prevent this complication , high pressure inflations and Post procedure IVUS (Intra vascualr ultraound may be done to ascertain lack of thromus between stent/vessel wal  interface)
  • Drug eluting stent evoked a special concern , when used in thrombotic milleu.This , has now been  proven to be  safe

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Coronary stents have revolutionised the management of CAD. Stents are metallic scaffolding devices that help keep the atherosclerotic plaque  plastered within the coronary arterial wall.Thus it gained the name angioplasty. Stents have aradial strength that  exerts a constant force on  the plaque . Since metals are unfriendly partners for coronary artery , we need to have minimum metal within the coronary artery.The stent struts weave around the lumen generally the stento/ artery area ratio should be as less as possible (15%).

But this has a trade off .The uncovered area of plaque tend to project into the lumen .This is many times not significant.But can be a problem if the plaque is very soft and bulk of the lipid core may reenter the lumen.this event is called plaque prolapse.

plaque-prolapse

What is the time taken for plaque to prolapse ?

Generally it is late event.But it can happen immediately after the procedure also.

Which type of lesions are more likely to have plaque prolapse ?

Eccentric and complex lesions especially with overhanging edges are prone for prolapse

What is the sequale ?

It can be benign.If there is a erosion due to stent struts can precipitate an ACS.It progresses into instent restnosis in many.

What is the angiographic appearnce ?

Angiographically it often appears as luminal  irregularity withi stented segment .

Many times , it may appear as a filling defect also.

Is there any specific issues in plaque prolapse in drug eluting stents ?

Coornary artery is not drugged uniformly by the drug eluting stents.In fact contact  lines of metalic struts  , through it’s micropore oozes the drug with polymer.Pathological studies have revelaed non homogenous drug penetration and resultant irregularity on the plaque surface.This could amplify the plaque penetration preferentially in few areas.

How to manage plaque prolapse ?

It should be managed as any other instent restenosis.Plaque resection with atherectomy devices has not solved the problem to the desired levels.A second stent is the most common approach advocated by the cardiologists.(Whic is not ideal though !)

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