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Posts Tagged ‘ptmc’

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ptca balloon for PTMC inoue 002

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PTMC is a revolutionary    interventional cardiology procedure .A fibrosed obstructed  mitral valve is  opened up just like that , with few wires and a balloon  .The procedure  performed within 30 minutes .No  anaesthesia . No surgery .No scar.

Thousands of procedures are done world-wide (Rich countries excluded    they do not have RHD) .We in our institute , have gained considerable experience in PTMC ,  and  have  completed  nearly  200 procedures  in the last  few years .

As we gain experience surprises also galore ! .Suddenly I realised this  funny (At least for me !) phenomenon  from the unique PTMC balloon design.

The other day  , there was an intense argument between two of my  fellows , who were in a dispute  .One was arguing  , the PTMC  balloon  had dilated the tricuspid valve erroneously  while  other was adamant , and  wholesomely convinced  , since the waist  had disappeared it must be the stenotic mitral valve.

The issue came to me  . . .  ended after a nice  debate !

PTMC balloon accura Inoue waist mitral stenosis percutaneous mitral commissurotomy .

Both PTMC balloons  (Inoue ,Accura) are made with innovative design  conceptualized by Japanese genius Kanji Inoue . The balloon has two layers of latex with a nylon mesh sandwiched in between.The latex  is compliant while nylon limits  it  and generates the required pressure .

The balloon is glued in a such a way ,  central part is  constricted  like narrow band .This makes sure the distal part of balloon inflates first , followed by  the proximal and finally the central .This  also help us  to  geographically to fix  the balloon across the narrow mitral valve orifice .

While , we must agree  this a great  concept , there is an an inherent issue when handling a hour glass shaped balloon with a  natural waist .There would  be great deal of confusion when we take disappearing waist as an index of relief of mitral stenosis.

We know ,the key  requirement is that ,  balloon’s waist  should match anatomical MVO .But , it is estimated  exact match  happens in a minority.  The issue gets further complex  with  subvalvular disease , double mitral orifice, eccentric orifices . The efficacy of PTMC is also determined by the appropriate contact of the balloon’s various pressure points . ( It is a balance of intra balloon pressure(3-4 ATMs)  and  the surrounding tissue pressure !)

Disappearing waists is not synonymous with opening  MVOs .All PTMC balloon inflations will shrug of the waist at peak inflation wherever you inflate .(Intra chamber inflations included !)

Final message

Please realise ,  falling pressure gradients and echo  documentation of  MVO  rules supreme  in assessing successful PTMC. Often times , disappearing waist  is  meagerly an optical  Illusion or gratification.

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What are the   structures that  can get punctured and result in cardiac tamponade during PTMC ?

  1. Aorta
  2. LA  roof ( Many parts of LA are extra pericardial . Still ,  if you are good enough !  you can enter the pericardium )
  3. LA free wall
  4. IAS  /pericardial space Interface (Stitch effect )
  5. LV free wall
  6. Pulmonary vein
  7. RA free wall

Traditionally  cardiologist’s major  fear is  confined to  accidental  aortic puncture . With growing  experience  &   inexperience   we  now know   PTMC  is vested with other  risks  for cardiac puncture other than Aorta .

  • LA roof  puncture can occur if the septal puncture is high  and  the movement of sheath over IAS plane is not smooth . ( Animated  to and fro movement across IAS is largely unnecessary !)
  • LA free wall when the guidewire is manipulated.
  • The  right atrial side of IAS  often  over shoots the LA side of IAS . This brings a unique situation where  Brocken-burrogh needle may  enter the LA through pericardial space .One may not be aware of this until you pull back the needle when pericardial
  • LV free wall  rupture is  rare with Inoue technique .Over the wire  balloon technique with a guide wire tip can cause LV injury
  • Accidental  pulmonary vein inflation with the balloon is  always  possible. One has to verify the balloon position in lateral view.
  • RA free wall should not happen  today . Still  a distorted RA anatomy due to associated  tricuspid regurgitation or stenosis . This can bring a surprise element to our understanding of IAS septal alignment .

Reference

http://interventions.onlinejacc.org/data/Journals/JCIN/22697/04019.pdf

Joseph G, Chandy ST, Krishnaswami S, et al. Mechanisms of cardiac perforation leading to tamponade in balloon mitral valvuloplasty.
Cathet Cardiovasc Diagn 1997;42:138–46.

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Left atrial clot is a  traditional contraindication for performing PTMC.  This rule was formed in the early days of PTMC.

PTMC  recently celebrated  its 25th birth day .  In India  it was  first  done by   GB Pant hospital by  Kallilulah in early 1980s.

Now most  centers  do it  routinely   like a diagnostic angiogram.  Even fellows can do it  with ease. (If allowed !)

We have learnt  the nuances  of septal puncture , maneuvering the transpetal needle and  the balloon  catheter  within the LA in the last two decades.it is also becoming clear  how the IAS anatomy  behaves in various LA and RA sizes  and pressures . So , the experts (Read again         . .  .experts !)  have relaxed the rule of the PTMC game !

PTMC  can safely be  done  if the LA   clot is confined to  the appendage  .Even clots  abutting just  out of LAA appendage  may  be tried if you have the expertise  akin to  Dr Manjunath and  his team  from the garden city of India .(Jayadev  institute ,  Bangalore probably has the largest  talent  pool for PTMC , In fact  they have  classified the LA clot according to size and location .)  Read the reference below.

If a cardiologist  is allowed to meddle the LA  filled with clot ,  why not a surgeon  do  a CMC   in the presence of LA clot ?

I believe old generation surgeons did it. I am told few surgeons  have specail talents to deliver LA clot off pump and complete a successful CMC   with lateral thoracotomy .  Fresh un organised clot can be flushed out of LA .
But currently doing a CMC  with LA clot is considered unscientific . Further  surgeons  often consider CMC as an inferior Job .They love to go on pump  and replace mitral valve with a  slightest provocation .  It need  be realised a half functional native  valve  is at any time   better than an artificial valve . In  developing countries    CMC  would make lot of sense when we confront with small LAA clots . One can do 5 CMCs at the cost of one mitral valve . Surgeons comments are welcome.

 

What  will happen  if LA cot gets accidentally dislodged ?

A stroke  or a systemic vascular event may occur  , but it depends upon the embolus size .Up to 2mm clot  debri can easily cross the cerebral  microcirculation and escape a major stroke.Showers of micro emboli can cause a lacunar infarct or vascular dementia.

By the way ,  I am curious to know what will happen to  these  clots after successfully  opening the mitral valve by         PTMC*  ?

PTMC can not be claimed as a cure  as long as the patient harbors the clot in a precarious location . So it  needs intensive oral anticoagualtion (or even heparin ) and many times we have observed these small clots disappear .

*Logic would  suggest an LA clot  with a  closed  mitral  valve  could be  much safer ! many times we have seen large LA clots struggle to get past the mitral valve because of critical stenosis.

A video of mobile LV clot from our institute . http://www.youtube.com/user/venkatesanreddi#p/u/40/zHdPtm32YZQ

Here there is no chance of PTMC ,  however good you are !

Future innovations

  • Distally  protected PTMC
  • Either you should trap it and remove it or desiccate it into minor particles.
  • Basket in root of aorta to capture  the clot in transit   may be a good  concept to try.

What  happens to LA clot following long term oral anticoagulations ?

Most disappear according to a study from JIPMER , Pondicherry , India .

http://www.ncbi.nlm.nih.gov/pubmed/14686666

Excellent PTMC  data   from Pakistan and Sudan

If you want to learn about PTMC  please note  the experts are not  in Cleveland clinic  or  from Great ormond  street

they are from the remote third world locations .

http://www.sudjms.net

http://www.ayubmed.edu.pk

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Interventional cardiology has grown leaps and bounds. We are in the era of percutaneous replacement of cardiac valves.  Mitral valvotomy for mitral stenosis is one the stupendous success  stories of interventional cardiology.

In PTMC,  we have a major cardiac valve disease ,  treated without anesthesia  in a  procedure   lasting about 30 minutes and patients  can walk  home within hours of the procedure.

The maximum such procedures are done in developing countries like India, Brazil, and many south Asian , African countries.

It is a procedure requiring continuous  fluroscopy in cath lab. This has been our traditional way of thinking. But now we learn , what we  require is an imaging    modality  for the entry of balloon into IAS and the stenotic  mitral valve .This can be Echo, MRI , CT scan etc not necessarily fluroscopy.

Why not echocardiography to guide the balloon in PTMC ?

This question was  answered successfully . Both TTE and TEE are used .Surprisingly   transthoracic  echo , by itself was   sufficient in many patients to complete  a  PTMC.

The following article in JASE (American society of Echocardiography )  opens new avenues for  echocardiography .The work was done in New Delhi India

http://www.onlinejase.com/article/S0894-7317(05)00073-8/abstract

The most surprising conclusion  from this  study is  , it is suggested complications like cardiac tamponade is less likely in echo guided PTMC !  as we are sure  where we re puncturing  and entering .

Advantages

  • Huge cost advantage.
  • Can be practiced in a wider clinical set up
  • Radiation free (Very important advantage  )
  • Live 3D /Echo and MRI are  expected to improve the  feasibility of this modality .

Caution about TTE/TEE guided PTMC.

  • Not every one can do this procedure.
  • Cardiologists who have mastered catheter based PTMC  can only understand the intricacies of  PTMC
  • While catheters can be easily imaged , when the procedure requires finer guidewire manipulations fluro is a must .
  • Currently this procedure should be done with a cath lab  standby
  • Tackling complications may be an issue , but the most dreaded complication cardiac tamponade is more easily recognised by echocardigraphy
  • Special training on this modality is to be strongly encouraged.Such thing is possible only in country like ours where RHD continues to be rampant.

Final message

Cath guided PTMC is considered  the gold standard .But ,  often  we create gold standards with impure gold ! The IAS puncture and mitral valve crossing is the most blinded  procedure in cath lab.

The same job can be done   better , with good   “ocular orientation”  by simple echocardiography

Often  in medicine , a  simple alternate technique   rarely can  compete with a proven  technique .Thus ,  these  techniques are denied wider  application and hence  fail to  prove  it’s worthiness.

Echo guided pericardial aspiration , MRI guided deep thoracic biopsy  are already established non invasive  assisted intervention , soon we can expect many cardiac intervention will be done in radiation free environment.

Unpopular treatment modalities  need not be synonymous with ineffective  and dangerous  forms of treatment.

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