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Posts Tagged ‘wall stents for priamry pci’

During   primary PCI , the weakest link  for a  cardiologist  is  , he is never sure whether  the  metal jacket  has covered the entire  disease segment with optimal apposition .  (Geographical miss is another issue !)

This is because  , even though the inflation pressure is  uniform  within the balloon ,  the required  apposition pressure is not the same .This is obvious as the lesion surface has a varying consistency and uneven surfaces . It is a  huge guess to quantitate the relative  contribution of thrombus and plaque  within  the 100 % occlusion  that has resulted in the STEMI. Hence  some areas may get over apposed and others lesser apposed. Further , the stent -vessel wall interface  in all likely hood enclose a   layer  of clot .This is almost certain  during complex primary PCI. One can imagine the sequel if this thrombus layer dissolves later ! (Edentulous stent )

It is surprising , why cardiologists has  so far not  thought  of a  self expanding stent  which  can snugly appose the vessel wall in this setting  . The   radial strength   from the  stored potential energy can be used up future use. This is most important  in first few days following STEMI  , when the coronary arterial lumen can vary depending  upon the

  • Vasomotor  tone .
  • presence of thrombus
  • Plaque   ploughing /milking  effect
  • Vascular remodeling

Cardiologists  deploy a stent  based on the morphology  on day zero of STEMI  .This may be  totally irrelevant  , since after a  few days    the lesion may change its morphology ,  thrombus may migrate , vascular  dimension may change. In such a  situation*  , a self expanding stent can tackle these issues very effectively by constantly adjusting  and fine tuning the luminal  diameter and  the apposition pressure . It  does not give any chance  for  thrombus to form  between the vessel wall and stent .

Here is a study that gives fresh insights regarding the role of self expanding stents during STEMI .

Note the “Auto adjusting”  of stent diameter  in the first few days after  the stent deployment, depending upon the luminal needs !

Animation

http://www.stentys.com/file_bdd/annexes/1284135580_video_stentys_en.swf

* Logically  during  primary PCI for  STEMI  ,  POBA and thrombus suction  may be the best option in many as all stent related complication is instantly eliminated .But it is a battered concept ,  most of the current day cardiologists would feel guilty to come out of  the cath lab  without a stent  in  primary PCI scenario  !

Final message

Self  expanding stents during primary PCI :  Is it a  perfect solution  for optimal stent apposition  ?

It seems so  . . . but  the track record of current cardiology devices never fulfilled the initial promises !

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