How is Angiogram Catheter Guided to the Correct Artery?

[TromboneAl]

I've been learning about angiograms (for book research), and I'm curious about the answer this question, and Googling hasn't helped:

How is the wire guided to the desired target? That is, it has to be threaded along the arteries and make turns into the particular artery that the doc is interested in. The doc can see the progress on an x-ray, but how does he/she cause the catheter to make the correct turns?

(Note: this isn't for the book. I'm just curious.)

 

[newtoseattle]

Its just luck. They keep pushing the wire up and down and taking pictures until it wanders into the correct one. There are different wire thicknesses, curves etc they can try until it goes in. But basically luck and patience...

 

[TromboneAl]

Its just luck. They keep pushing the wire up and down and taking pictures until it wanders into the correct one. There are different wire thicknesses, curves etc they can try until it goes in. But basically luck and patience...

Wow, interesting. Thanks.

 

[Sojourner]

The doc can see the progress on an x-ray, but how does he/she cause the catheter to make the correct turns?

So the patient is being X-ray'd the entire time the catheter is being guided to the artery? Doesn't that result in a high dose of radiation? A 10 millisecond chest x-ray is one thing, but several minutes during a cath procedure must bathe all the internal organs with thousands of times more radiation.

 

[Scrapr]

So the patient is being X-ray'd the entire time the catheter is being guided to the artery? Doesn't that result in a high dose of radiation? A 10 millisecond chest x-ray is one thing, but several minutes during a cath procedure must bathe all the internal organs with thousands of times more radiation.

wouldn't the catheter be camera guided? Near the end of my wifes cancer treatments they tried to clear an artery. I think it was called Interventional Radiology. I had never heard of it before

 

[TromboneAl]

So the patient is being X-ray'd the entire time the catheter is being guided to the artery? Doesn't that result in a high dose of radiation? A 10 millisecond chest x-ray is one thing, but several minutes during a cath procedure must bathe all the internal organs with thousands of times more radiation.

Lena had a coil inserted into a misbehaving blood vessel in her brain via a catheter introduced in her groin. Her hair thinned and went away on some parts of her scalp as a result of the radiation.

So, yes, it's significant.

Googling shows me:

The typical effective dose for a chest x ray (PA) is 0.02 mSv and for angiography is 10 mSv.

From: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1861453/

 

[bjorn2bwild]

Its just luck. They keep pushing the wire up and down and taking pictures until it wanders into the correct one. There are different wire thicknesses, curves etc they can try until it goes in. But basically luck and patience...

A more complete answer -

With a traditional catheter, the catheter tip is directed by manually rotating the catheter about its axis and pushing it forward into the desired vessel, often over a variably stiff coaxially placed guidewire.

https://jcmr-online.biomedcentral.com/articles/10.1186/1532-429X-14-33

 

[Cavechild]

It's done by a skilled / trained physician. They know the anatomy. They lead with a guide wire that has a curve on the end. They can torque the wire to turn it toward the vessel they want. Once it's pointed in the desired direction, they advance it forward. They continue this until they are in the treatment site. The catheter is then slid into place over the wire.

This is all done under fluoroscopy (x-Ray). The wire and catheter have markers (platinum) that are visible under x-ray

 

[fasteddie911]

Also to add, the fluoro they use isn't constant but quick bursts every so often to check on things. Concerns for patient radiation safety is probably less than it is for doctor, nurses, techs, who are doing this all day everyday. Certainly safety and protection have been improved dramatically over the years.