stent removal

[mfr]

Once a heart stent has collapsed, can it be removed?

[kenkeith]

Once a stent is placed in a coronary artery, it can't be taken out. Cardiologists can perform procedures to reopen a problematic stent, and sometimes even put a new stent inside an older one, but removal isn't an option.

[gman2009]

I have heard of a procedure called an endarterectomy where a stent can be removed.  It is usually done in cases where an artery has been stented stem to stern (also called a full-metal jacket).  There is no-place to bypass too if the patient needs bypass surgergy due to poor response to stents (metal and drug-eluting).  It is done during a CABG, so you are already talking about major surgery, although there is one case I have heard of where it was done off-pump (artery needs to be in the front of the heart for this).  As far as removing the stent without going into the chest through an incision, I have never heard of that and don't believe it would be possible (how would you get the stent out?).  

I am not sure who in the U.S. does this, as most of the papers have been from doctors in Australia and Japan.

[kenkeith]

.
Endarterectomy combined with stent removal is an uncommon, technically demanding surgical procedure, associated with good results.  Vessel wall architecture remains well preserved after surgical removal of stents implanted in juvenile arteries and veins. However, stenting and subsequent surgical removal results in a high risk of venous thrombosis (probably due to the lower blood velocity, lower pressure, and the absence of pulsatility in venous vessels).
Unless it is a matter of life or death and infection is involved stent removal is a very high risk procedure and avoided.  The treatment and prognosis of coronary stent infection Intravenous antibiotics are the mainstay of therapy in patients with coronary stent infections. However, given that foreign body infections are extremely resistant to antibiotics and host defence mechanisms, surgery with debridement and/or stent removal may be required. Indeed, six of the ten patients with documented coronary stent infection underwent a surgical procedure, whereby the infected stent was removed completely in three subjects and partially in one patient. However, it is noteworthy that half of the surgical patients died, suggesting only a limited benefit of surgery in this population. Based on the currently available data, mortality may be as high as 40% despite antibiotic and/or surgical treatment. This classifies coronary stent infections as a life-threatening complication.

There is a patent pending and no information on the status. The invention relates to an assembly for the removal of a stent from a body vessel without an operation being necessary to gain access to this stent. This assembly has for this purpose an expandable element, connected to a pulling device, the outer surface of which is covered with an adhesive medium and which, when the element is positioned inside the stent, is expanded and lies with its outer surface against the inner surface of the stent and thereby causes an attachment between this outer surface and the inner surface of the stent. The element with the stent attached to it then can be withdrawn via the body vessel.
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[gman2009]

Ken,

Are you a doctor?  Just curious.  This is a subject I am interested in as I have 25 stents and will probably get more.  However, my LAD is a full-metal jacket and there is no place to bypass to.  The only way it could be done would be to remove one or more stents.  I have seen an article from Japanese surgeons where this was performed on 11 patients with good results on 10 (one had low output issues).  All patients had full-metal jackets on the LAD with constantly recurring re-stenosis.

I would be very interested in following the stent removal patent.  If I do becomes a candidate for bypass surgery, it sure would be nice to have a safe, effective way to remove a stent.

[kenkeith]

Almost all of the medical research is available and public domain to all interested parties that is available to the medical community.  I was not stating an opinion nor giving specific medical advice, but I am and have quoted non-peer review articles in my post. However, I will give an opinion and for what it is worth, I believe from a common sense perspective to implant a series of stents is not very prudent.  There will be blood flow turbulance from gradients induced by the series of implants and that is known to cause plaque buildup and restenosis. Why was it necessary to implant 25 stents?

It appears your interventional cardiologist has painted himself/herself into a corrner to use an analogy...  The patent pending originated in Switzerland and was dated (if I remember correctly) 1998.  No further information.  I don't believe there is a high demand to remove stents unless there are infections uncontrolled by meds, and possibly a young person that has outgrown an implant, but most very young individuals don't have implants! .... I wouldn't buy stock in a fledging enterprise that is manufacturing a gizmo to remove implanted stents, would you!.  

If and when you may be a candidate for a by-pass, would it be necessary to remove the stent?  Please cite the Japan article.  Take care.

[gman2009]

I believe it would as I have a full metal jacket stem-to-stern in my LAD, so where would the bypass occur in the LAD?  Where would they graft the vein or artery?

Here is the Japanese article:  ats.ctsnetjournals.org/cgi/content/abstract/79/2/558

Bye for now.

[kenkeith]

QUOTE: "I have heard of a procedure called an endarterectomy where a stent can be removed.  It is usually done in cases where an artery has been stented stem to stern (also called a full-metal jacket)".

If endarterectomy is successful, why would the removal of the stent be necessary?  Endarterectomy opens the vessel permitting the passage of blood.  If there is infection, etc. the stent can be surgically removed, but there is a high probability for thrombosis.

There is some demand to remove a stent implant in a child's vessel and later surgery because of mismatch of stent size and vessel growth during development may hopefully be avoided in future with the use of biodegradable stents10–13 and the development of the so-called breakable stents in infants and children.14 These stents are still experimental and the biodegradable stents are currently only available up to a maximum diameter of 3.5 mm, which limits the use in older infants and children.

If there is no more room for another stent, a bypass would be at the distal down stream location from the last stent, as it may not be necessary to patch an abutment to the last stent implant.  

[gman2009]

What if the most distal part of the downstream location had a stent?  I believe the article I cited was for cases such as that.  Remove the stent and then bypass to that location.  My cardiologist has already informed me that I cannot bypass due to the number of stetns in my LAD.  My circumflex and RCA look like they are healing really well, but my LAD is causing me great difficulty.  I barely survived the attack as the occlusion was, for all intensive purposes, 100%.  I was only saved by a collateral that was barely keeping some of the muscle alive.  I have since recovered competely and the tissue death reversed (which means it was not quite dead).  My LVEF went from 50% during my most recent surgery two days ago to over 60%.

[kenkeith]

It seems to me if you were to need a bypass the stent that is blocked can be removed at the time of the bypass if that is not the only option, however, a successful rotor rootering will open the occluded location and then sten again or not.

When I mentioned distal location, I as thinking that surgeon can reroute the blood flow to feed the deficit area.  Your hypothesis is really a question for a surgeon.  

[dipindhingra]

My mom has over 75% blockage in one artery and few yrs back she developed ASD(hole) in heart for which she was recommended open heart surgery.

And now for blokcage , they suggest stent.Docs said stent has a life of 4-5 yrs, after that you need to change.
is it a risky procedure. please suggest


Dipin
India

[ed34]

Stents can be removed during the angioplasty procedure, but this possibility is short lived as tissue forms and bonds to the stent. Special tools collapse the stent, draw it into a tiny sheath to hold it collapsed, and then it can be withdrawn from the body. This is not a possibility when tissue has attached to the stent, then an endarterectomy has to be performed. An endarterectomy is a normal procedure prior to bypass grafting anyway, it creates a clear area in the native vessel to accept a new feed.

[kenkeith]

Qoute:"To: gman and kenkeith
My mom has over 75% blockage in one artery and few yrs back she developed ASD(hole) in heart for which she was recommended open heart surgery.

And now for blokcage , they suggest stent.Docs said stent has a life of 4-5 yrs, after that you need to change.
is it a risky procedure. please suggest"

>>>>The life of stent implant can be permanent, but it is necessary to stop or slow the progession of plaque buildup within the stent as well as systemically.  With 75% blockage there may not be a need to treat other than medication.  It is not risky to have a stent implant.  The individual remains awake but given medication for relaxation....there is no discomfort whatsoever and no anxiety.

ASD is a hole in the wall that separates the two upper chambers and usually congenital. Do you mean the hole has progressed where treatment is required?

For some insight and it ASD appears to be congenital: "Some congenital heart defects may have a genetic link, either occurring due to a defect in a gene, a chromosome abnormality, or environmental exposure, causing heart problems to occur more often in certain families. Most atrial septal defects occur sporadically (by chance), with no clear reason for their development."

If and when the defect becomes a problem, there may be a cause for intervention. The problem would be what is called shunting and that means there is blood passing from one upper chamber to the other side's upper chamber (left to right due to higher pressure in the left atrium.  A small opening in the atrial septum allows a small amount of blood to pass through from the left atrium to the right atrium. A large opening allows more blood to pass through and mix with the normal blood flow in the right heart. Extra blood causes higher pressure in the blood vessels in the lungs. The larger the volume of blood that goes to the lungs, the higher the pressure in the lungs. Can/will enlarge right atrium as well as respiratory problems.

Usually, if there is going be open heart surgery, there will be a bypass of any occlusions rather than stent.

[ed34]

"Docs said stent has a life of 4-5 yrs, after that you need to change"

I have one which has been in my obtuse marginal (OM1) coronary artery for over three years now. It is still fully open with no sign of disease or other problems. I'm not sure where your Doctor got the information from. I can't see my stent developing problems in the next year or so.

[kenkeith]

Dipin, I answered this thread before reading your e-mail.  If you have any further questions you can followup by e-mail if you wish.  Thanks for your response.

[dipindhingra]

I am sorry. I am not able to track my posts, as I dont recieve any updates, so I check manually now that you replied me here. Well thanks a lot for your replies. Its very valuable.

And coming back to what you said, the ASD that she is having has not enlarged since last 15years and even her heart size has not grown or shrunk. Also the ASD has not extended to the portion in which there is blockage. Actually ASD is separate problem.

But right now, its blockage. My mother is not able to walk even 2 steps ow, if she walks or even go to toilet or eat a little more food she feels breathlessness.And she asks for water all time. Currently she takes lots of sorbitrate tablets to keep her heart stable during such thing.

I also heard my father saying yesterday that in the latest ASD report, it shows there is a leakage in a valve also.


I really dont know how to help my mom.

[kenkeith]

Your mother has the symptoms of reduced cardiac output.  And she should contact the doctor to get treatment.  A low cardiac output can cause lung edema because the blood received from the lungs backs up into the lungs because the heart does not have enough strength to pump adequately.  What do tests indicate?

[EPI102]

I had a stent placed in a blocked LAD. I was born with a bi-directional atrial shunt (hole) which was determined to be a birth defect. Due to the birth defect blood passes thru the shunt losing  oxygen and allowing tiny clots to form which were passed to the brain causing and other parts of the body causing (a TIA in 1997 and a mild stroke in 2005) the heart attack. The heart attack was due to the blocked artery and the doctor did not know if the artery was blocked due to tinay clots from the birth defect or plaque build up.  The attending nurse advised my family that I could follow the regime of my doctor and dietician and the stent could be surgically removed. I have since followed my diet and reduced my weight. I anticipate having the stent removed. There are also two types of stent; the drug eluting stent and the metal stent. I had the metal stent inserted in my LAD. Stents are removed in the same fashion inwhich they are placed.

[ed34]

"Stents are removed in the same fashion inwhich they are placed."

I had a stent in Feb 2007 and new artery tissue has grown across/through the scaffolding. So in effect, the stent is under the surface of the artery lining now. How can they remove it without tearing my artery apart?

[blondepompom]

A cardiologist placed a stint in my right renal artery 10 years ago. I now am having trouble with my bp due to a slight narrowing at the stint site. My urologist us sending me back to Duke university to see about a stint replacement. What information can you possibly give me on this.

[ed34]

They will have to look at angiogram images and make a decision based on the circumstances. It may be possible for them to balloon the site and insert a new stent inside the old one. It could be that the disease is only partially in the stent, meaning they may insert a long stent to cover all the old stent plus any new diseased section next to it. It maybe that only a part of the new stent has to go inside the old one. It depends on the circumstances.

[jimabcde]

     I'm 66.Last year I had a quad coronary bypass.  I also went to a vascular surgeon to get my left iliac artery stented for PAD. After the operation the surgeon informed me that he also threw in two on my right leg to "even the flow". It's bad enough that I didn't need or request these, but one of these is is new flexible stent he put in the angle of my right hip.
     The thing is rated for a mean lifetime of 40,000 bends before metal fatigue produces fractures and the thing begins shredding my artery. When this thing breaks, which is 100% guaranteed down the road, what can I expect?
   I've read that there is a 40% mortality rate in arterial stent removal. I've also read that arterial stents are never removed in case of failure, just re-stented over. However, this thing will, of necessity, have to be removed!  
   I've looked around but I haven't come across any literature on procedures to remove these new flex stents when they eventually fail.   I'm seriously worried.Every time I sit, stand, or take a step, I'm that much closer to the stent failing.
    Have failure modes and removal options been studied for these new flexible stents?
   Specifically what will be the odds of me keeping my leg, or better yet, surviving the removal of the stent.
  I've been told, unofficially, that when this new flexible stent finally fractures, which the laws of physics guarantee, it will absolutely necessitate removal of either the stent itself or the section of artery it occupies, which means losing my leg at the hip. Is this correct?
    It seems to me that this new flex stent technology has been implemented without adequate forethought being given to the consequences when the devices reach their flex lifetime and inevitably fail.


Jim

    
  
      
      

[ed34]

I think you are perhaps misunderstanding the function of a stent. It isn't always in the inner part of the artery (lumen), where the blood flows. It acts as a mesh scaffolding to hold the artery open, and allow repair to take place. In a matter of weeks/months the artery makes a new lining (endothelium) which grows through the stent. This will greatly reinforce the stent too. In a few weeks the stent is basically buried in the artery wall. When I had an angiogram a couple of years ago, they couldn't see the stents I had placed a year before. They had to refer to paperwork to locate their position because my artery was like new. I think after the 2-3 weeks you can stop counting the twists and turns, because the stent will be buried and reinforced in the artery wall.

[ed34]

I don't think there is really any difference with drug/bare stents long term, not once they are covered with a new lining. The small benefit seems to be with short term, the drug slightly inhibits scar tissue growth. The problem though is that a drug eluting stent is still mesh, so there are a lot of holes which do not deliver the drug to tissue. Estimates say that around 10-20% of the area around the stent receives the drug. This still leaves a lot of opportunity for scar tissue formation. In Europe the Drug eluting balloon was developed. It can be used for arteries which are too small for stents, and as a preparation for drug eluting stent delivery. The balloon delivers the drug to 95-100% of the artery.

[jimabcde]

I don't know if your reply was to me, ed, but I'm familiar with all that. I know the stent becomes imbedded into the artery's tissue.I understand that it becomes a scaffold that is incorporated into the artery wall itself.
  What I am concerned with is this new class of stents that are designed to flex and bend.  I have one in the angle of my hip, and manufacturer specs state that I have a mean number of bends before the stent is GUARANTEED to break. Every step I take, every time I sit or stand I'm one flex closer to the mfg rating of 40,00 bends at which time I can expect the wires to fracture and begin chewing thru my artey. Metallurgy and the laws of physics guarantee that it will fail thru metal fatigue!
.
   I'm trying to find out my chances of survival or saving my leg when the inevitable does happens.