Posts Tagged ‘instent restenosis’

Instent restenosis is a  common problem.

Diffuse long segment instent restenosis is somewhat rare.

We  encountered one such patient who had diffuse instent restenosis of RCA.

ISR is ssupposed to be rare in DES, but here ISR occured with a Cypher stent  one year following implantation

He presented with angina which  was relieved  by plain baloon angioplasty.

 link to a  related article in  this  site  regarding the mangementof ISR.

Read Full Post »

How do you tackle  In-stent restenosis  (ISR) ?

  1. Deploy another BMS
  2. Use a third generation  DES
  3. No . . . first  generation DES(Paclitaxel )
  4. Consider Plain balloon angioplasty.(POBA)
  5. Refer for CABG.
  6. Fall back on medical management.(Ingloriously  referred to  as  “No option” patient !)

Answer:  Please  note , there is no single response answer for this question .

Instent restenosis (ISR) is   commonly seen with BMS .This is primarily because  we are busy blaming DES  for stent thrombosis  and we do not want to give a double blow to DES .There is a  significant population  roaming with ISR  involving  DES .  BMS is in vogue for nearly 2 decades, hence it is natural to see more of it.  In due course ,  DES  is expected to catch up with BMS  and would lead in ISR as well .

The issues in PCI for ISR

Though any of the above 6 strategies may be appropriate ,the urge to put another stent within the IRS ,  prevails over all other options in most centers. This is more off an Interventionist talent  show off  !

Please remember , the common  principles  must apply in all patients before an PCI  . Simply stated , this  principle involves  assessing  symptoms, residual  resting  ischemia, myocardium at risk  during stress, viable muscle mass etc .Lesion characteristics  should come last in the work up. ( A cardiologist  should not  report  a coronary angiogram  , if   does not  not know  basic clinical parameters.)

It is  good  to have a  rule  that  “reserves  intervention”  for ISR  only if the  patient  has refractory angina. 

Can you promise  relief from dyspnea

Contemplating  PCI for  patients with dyspnea as the main symptom is really tricky one.Unlike angina ,  dyspnoea  can be attributed to so many factors other than coronary blood flow.(Apart from LV EF , Iscehmic MR,  A transient diastolic dysfunction , lung function , volume status, renal function , physical conditioning etc)

Opening  ISR in the belief it would improve LV function is highly questionable even if viability is documented.

What is the most important step in the decision making prior to PCI for ISR ?

* Most important step  in ISR management is  probably  spending  sufficient time ,  involving  experts ,  ” democratically  debating”  the indication and techniques  in your institutional cath conference.

Once you document the necessity of intervention* The following things  are possible .

  1. If  the patient has diffuse in-stent stenosis , especially  the  proximal ones or that  involves  branch points,  it is wiser to refer  them for CABG.
  2. Discreet and focal ISRs can safely be attempted for repeat PCI.
  3. BMS or DES  ?  This  is  debated. Current preference is to use  a DES. (Many feel ,first generation DES -(Paclitaxel)  scores over Everolimus in this situation )
  4. Is POBA  possible for IRS ? Can a balloon do a job where a stent has failed ? . No  body is trying it .Many Feel guilty to  do it .  POBA for IRS is a failed concept without even trying it !  One  way of reasoning  is IRS occurred  only  because stent was  never indicated in the first place  in that  location  and a POBA would have been the choice in the initial attempt itself .So let us not make the second error !  ( May be , if  Gruientzig is alive today ,  might have  used  POBA  for ISR very effectively ! )

Issues for which  we will never ever know the answer !

In future any of the following combination of  stents  will occur in tackling ISR.

  • DES covered  BMS
  • BMS covered DES
  • Two BMSs
  • Two DESs
  • Paclitaxel covered Everolimus
  • Everolimus covered Cypher.
  • Overlapped DES and BMS
  • DES covered beta irradiated IRS
  • Rotablated BMS (Yeh metal crushing !)  followed with  DES jacket !

How does the two metals ,  two drugs in various combinations interact with  the tender coronary  endothelium ?

Endothelium is an endocrine organ. It has  to secrete as  many pro and anti homeostatic molecules (Nitric oxide, endothelin etc).This has to be  kept in mind when we develop newer and exotic devices. Of course ,  we claim our  aim is primarily  to provide  relief  to  our ailing patients , but, as things stand today  , there is a distinct risk of  converting human coronary arteries into corporate playgrounds !

Reference :


Read Full Post »

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.


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 !)

Read Full Post »