0:00

This is an interesting case.

0:02

It's a younger patient in their sixties prior bypass graft,

0:06

and, um, kind of an interesting, relatively rare situation.

0:10

I wanna show you one thing. We've got a sternotomy

0:13

and, um, so you know,

0:15

you're gonna make sure you scan from the junction

0:16

of the first rib of the clavicle.

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This is a scan that we would've missed though

0:20

some of the bypass grafts.

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If we didn't have history. There's an entire, uh,

0:24

abdomen included here, uh, for a reason.

0:26

So let's look through the graft.

0:28

Perhaps you didn't get good history or weren't given any.

0:30

Um, so first things first, Lima is off the chest wall.

0:34

The RIMA is also off the chest wall, so you know,

0:38

bilateral arterial grafts.

0:40

Um, and I won't belabor them too much other than

0:42

to say the Lima looks okay.

0:43

Uh, we'll worry about the runoff. That looks pretty good.

0:45

We'll worry about that later. Um,

0:47

and then let's find, uh, the next graft.

0:50

So the next arterial graft would be the rema

0:52

that goes to the right side.

0:53

They tend not to cross, uh, the chest if they can help it.

0:56

Um, and that goes to the, some part of the distal RCA, uh,

1:00

at least over to this acute marginal branch.

1:03

And then looks like there might be an occluded segment,

1:05

but a patent, uh, distal RCA Next, uh,

1:10

vessel I'm worried about is a circumflex.

1:13

And I do see a cannulation site here.

1:15

That's not a pseudo aneurysm.

1:17

Uh, if you're not sure though, it's really nice

1:18

to have a non-contrast scan just for teaching purposes.

1:21

Let's pop that up. And so I'll throw the non-con in

1:24

here and you can see that's just calcium.

1:25

That's not a little pseudo aneurysm.

1:27

I really like having a non-con scan

1:29

to sort the questions like that out.

1:30

You never know when they come up. Um, okay, the left

1:33

main certainly looks stenotic, if not occluded.

1:36

And then you have a bunch of disease

1:39

and stents in the, uh, circumflex.

1:42

Um, and then as I come down, we know that the, uh,

1:47

RCA is your dominant vessel,

1:50

but there's this extra vessel right here, we can kind

1:53

of follow that downward and, uh, we lose it.

1:57

So there's some kind of a bypass that's going

1:59

to the distal RCA branches.

2:02

And you know that that's a very, uh,

2:03

diseased posterior descending artery.

2:06

So this was known

2:08

and it was in done with an inclusion of the abdominal

2:12

aorta on this scan.

2:14

Actually, a better way to show that would be just

2:16

to look at this volume rendered image here.

2:19

And so that's actually a gastro artery bypass graft

2:22

to the distal RCA.

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Uh, it's rarely used graph,

2:25

but you'd really need to

2:26

clear everything including the inflow.

2:28

So you have to have a much more inclusive scan.

2:31

So here's the full field of view.

2:33

So this scan range is far longer

2:34

than all the others I've shown you.

2:36

And you can trace this bypass graph from the distal RCA

2:41

and then just follow it backwards all the way down past the

2:44

liver and the stomach down, down.

2:48

And here it is where it begins life

2:51

as a proper gastro block artery.

2:53

And then you can follow that back to its origin.

2:55

And so, just like in the Lima,

2:57

you need to clear this subclavian.

2:59

Uh, in the gastro oleic,

3:00

you wanna make sure there's not a stenosis on any

3:02

of the donor vessels.

3:03

So the aorta, the celiac artery, this is the,

3:08

the SMA, but that's not, uh, relevant here.

3:10

But if you did have a stenosis like that,

3:11

you'd at least wanna investigate carefully.

3:13

So kind of a nice case with a variant anatomy.

3:17

So let's see what it looks like, uh,

3:19

on an invasive angiogram.

3:21

And here we've just gone to the, the right coronary artery.

3:24

And so there it is.

3:26

So the RCA occlusion and, um, kind of a, a stump.

3:30

So not unexpected.

3:31

The RCA is bypassed by the RIMA as well as by

3:36

that gastro hyperopic artery.

3:38

Little harder to find those anastomosis,

3:40

but here attempt to cannulate success.

3:44

Um, okay, there's the graft. Follow that down.

3:49

So to the distal, uh, RCA

3:53

looks like we did not select out for the gastro pathic,

3:55

but it's already known by the CTA.

3:57

So we've spared them that There's actually some nice

3:59

trials, uh, that have come out.

4:01

One of 'em is the bypass CTA trial, just showing

4:03

that you can abbreviate the evasive angiogram

4:06

and actually have better outcomes if you can count on the CT

4:08

to do clearance, um, of some vessels ahead of time, as well

4:11

as to guide

4:14

and tailor the protocol so you don't have

4:16

to inject as much contrast.

4:17

And as you know, the, the arterial side contrast tends

4:21

to have a lot more deleterious effects

4:22

than venous side contrast.

4:24

So, um, this is just a look at the distal LED,

4:26

you can see the anastomosis

4:27

and it's also a nice example of

4:29

how the invasive angiogram has a very

4:32

superior spatial resolution.

4:33

So we were not quite seeing the LAD well on the ct,

4:36

but you can see it nicely.

4:38

It's a little finer spatial resolution.

4:40

So a unique case with unique anatomy.