Practical question on operation technique

[CureOrBust]

I'm sorry if I have missed the explanation of this (and the laziness in not searching the net for angioplasty... ). Nonetheless, from what I understand, both the stenting or ballooning of veins using "key-hole" entry would require that the surgeon has a "view" as to the real-time placement / location of the stent or balloon.

My question is, is / has / was this done with X-ray? CAT scan? MR? or other?

I am just inquisitive regarding the radiation doses from the procedure.

[Loobie]

It's called a venogram I believe and there is radiation as I saw Dr. Dake don his leapord print lead vest before surgery!

[mrhodes40]

Lew has it.
The Flouroscope is at the operating room bedside and it hovers over you so when they put dye in they can see the veins. The f-scope is a kind of real time x-ray deal.

I think you are asking if they have little cameras inside the veins to see and I assume that they might for some kinds of repairs but it is not needed for stents and balloons.

If they are going to be nipping something out and repairing a valve or something I assume might they have one of those itty bitty cameras that goes inside like they use for a "keyhole" knee surgery....but I do NOT actually know! The one for the knee surgery is way too big to fit in a vein, and it goes in to one hole while another hole holds a instrument that can do a repair.

[GiCi]

There are not cameras at the tip of the catheter which is introduced in the venous system through a puncture of the femoral vein in the groin. The anatomy and the flow pattern inside a vein is visualized by injecting a contrast medium (a liquid which is seen by the x-rays). This procedure cannot qualify as "surgery" because is a diagnostic test. Even the dilatation of the vein or the placement of a stent are not qualified as "surgery" but as "interventional radiology". The procedure is undertaken with local anaesthetic to the port of entry (the groin) and is a "day procedure".
GiCi

[zap]

Interesting question CureorBust - It does seem that radiation levels can be a concern with long procedures ... Fluoroscopy can cause radiation burns, as well as risk for longer term effects like cancer and cataracts ... eek!

http://www.google.com/search?q=Fluorosc ... tion+stent

The radiation-induced cancer risk may be considerable for younger individuals undergoing transluminal angioplasty with stent placement.

Seems that there are ways they can reduce the amount of radiation the patient is exposed to (ie http://www.circ.ahajournals.org/cgi/con ... /89/6/2710)

Would love to hear more about this from anyone more knowledgeable ... kinda creepy, especially so close to the brain!

[skydog]

The best one can do post any kind of radiation exposure is to load up on the antioxidants. Protect your overall health with a healthy diet that promotes healing. Time is the only true way to loose the radiation in our body. I think one of the reasons we only get checkups in two month intervals as to avoid overloading the system with too much exposure. Yes it is a little creepy when you know you are the target of the Ray Gun! I am sure that Stanford uses the best and safest equipment to date. I am sure Marie or Cheer will have some insight to this subject. Hope that eases your mind a little. Cheers, Mark

[CureIous]

Also you are required to remain very still. This I believe is so stuff don't move after the last picture was taken. Like when they are actually moving things around in there, fishing the wires up and such, yes they need to be "live" but it's not on the entire time you are in there either so a 2 hour surgery isn't 2 hours of xrays. Not trying to whitewash it or anything.

I found an interesting study that specifically dealt with Xray/fluoroscopic exposure to patients undergoing coronary angiography. Seems close enough for government work insofar as the catheterization is from the femoral artery etc etc.

Seems the exposure is also "dialed in" to the patient size, one interesting tidbit that popped up, the machines made in India were dialed in for the typical Indian patient and may need to be adjusted up or down for the average patient in whatever country they were going to, if I read that correctly. Also the more tissue that it goes through, the more dosing is needed.

I'll post up some cherry picked parts and link to the study too. Interesting read.
Much more at the link. <shortened url>


Major factors contributing to the overall radiation dose would be from the use of high dose rates present in these machines and the length of the fluoroscopy. The cardiovascular machines dedicated for cardiac procedures are invariably imported from developed countries and the default preset exposure settings are based on the patient size of those specified locations. Since the weight and body surface area on Indian patients are lower in comparison with patients of other countries, it would be advisable to setup appropriate dose modes for the Indian population. To achieve low dose levels during cardiac procedures, the image intensifier entrance dose rates could be reduced according to the body mass index of the Indian population. However, radiation intensive angulations do not enable substantially better image quality despite increasing image intensifier dose levels.[9] In the current study also, optimization did not result in any significant reduction of image quality. It is noteworthy in this context that thin patients should be examined at low dose levels. Selection of appropriate protocols (optimized and factors meant for pediatric patients) with corresponding dose levels should be encouraged in order to obtain radiation doses as low as reasonably achievable (ALARA) without sacrificing the image quality.

¤ Conclusion


Though the radiation dose imparted to patients does not present any alarming situation with regard to ill-effects of radiation, it would be prudent to optimize radiation dose to patients undergoing CA. Since there is a frequent change in the various imaging modalities, reference dose levels should be audited on a time to time basis so as to keep the doses as low as reasonably practical. Reduction of radiation dose to patients and consequent minimization of overall radiation dose during CA in the current study was due to use of adequate copper filters with optimal exposure parameters.

[Jamie]

Well I think we can consider the cardiac surgeon's answer definitive!

[jay123]

as a parody of the American express commercial-
- ms taking away our mobility..
- ms making our life miserable..
- ms genrally sucks..
vs risking some radiation for a potential 'improvement' (i was looking for a good word similar to cure, but not cure!) --- priceless!

lol - just saying some radiation risk is worth the potential!

[CureOrBust]

No, I wasn't talking about "little itty bitty camera's" marie; hate to point out the obvious, but even in colour they would be all red... blood being the way it is n all. (I couldn't resist ) I am guessing if they need to "see" a valve better than what they can visualise otherwise, we are talking open surgery. And I think that's what Erika is up for, as she has an inverted valve (seen on ultrasound, I think)

And yes, I do understand its the choice between two evils. I just believe in having your eyes open and knowing all the facets, and making an informed decision (no matter how simple the choice may seem )

I also wanted to find out a little of actual numbers as to the level of radiation. I read on the Wiki I think, that a CAT scan of the torso comes in at somewhere between 50 to 100 chest X-rays equivalent. I have already had a CAT scan of my lungs (and 1 chest X-ray). As far as I understand, radiation is a cumulative thing, which as you accumulate, your risk for "side-effects" accumulate. From my simple understanding, it's not a case of "loosing" radiation over time, its a case of the damage accumulated; the more radiation experienced, the more damage, the more chance that damage could develop into something like a cancer. Its a numbers thing.

If the operation itself was fairly low in radiation, I would be more comfortable with a CAT scan now, instead of waiting for the MRI protocol.

I guess the real question would be "anyone know the rough X-ray equivalence of the flouroscope during the stenting?"