0:00

So this next case is a patient in their seventies

0:04

who had had a prior bypass surgery.

0:06

This one is a nice example of

0:10

sternotomy wires on this radiograph,

0:12

which I'm sure you're familiar with.

0:13

But again, uh, it's nice to just alert your technologist

0:16

that in case a case like this comes through

0:18

that we haven't let them know, uh,

0:19

or protocol that to include the Lima graph,

0:22

you wanna make sure you get that whole chest again,

0:24

making sure you cover the anatomy that is the junction

0:27

of the first rib and the clavicle that'll get you the lima,

0:29

which is usually the most common bypass graph.

0:32

The next thing I, I guess is worth doing is

0:34

just kind of getting an overview.

0:36

And this is a nice case

0:37

where the volume rendered image kind of helps.

0:39

Um, there's not a ton of use for volume rendered images,

0:42

but this is one of the really killer apps, if you will,

0:45

for volume rendering

0:46

because it helps me see the bypass

0:47

graft anatomy really well.

0:49

So first thing I do, uh, just like that figure we showed,

0:52

you can see the Lima graft coming down.

0:54

It's the most commonly used arterial graft,

0:57

and that comes off, uh, the subclavian on the left

1:00

and it goes right to the LED.

1:02

Um, and that's kinda an important one.

1:03

So that's, uh, and we know the

1:05

patency rates are really good there.

1:06

You can see a lot of clips along the course,

1:08

and that's to be expected.

1:10

Um, I also see another graft going toward the circumflex.

1:12

This is a more tubular large graft,

1:15

probably a saphenous vein graft.

1:17

And then I don't see anything on the right going to the RCA,

1:20

any, any right-sided revascularization.

1:22

Um, I do see that there's a little bit piece of, uh,

1:24

something dense on the aortic wall right here.

1:26

So we'll look at that and make sure that

1:28

that's not an occluded graft osteo.

1:31

And then another thing you can see really easily here

1:34

that it's a right dominant patient,

1:36

the RCA supplying the PDA and PLV.

1:40

So we already know, um, there's been a cabbage,

1:42

there's a little bit of arterial and venous grafting.

1:46

And then we're gonna look at more at

1:48

the, uh, rest of the anatomy.

1:50

So just start with axials.

1:51

You can follow and you wanna make sure you clear the, uh,

1:55

osteum of the left subclavian, which looks fine,

1:57

some disease, but no stenosis.

1:59

Following this up, there's the vertebral coming off

2:01

and then there is the left internal mammary.

2:04

Um, if you're not sure if a mammary has been used,

2:07

you could look at the opposite side.

2:08

And this is a right internal mammary graft.

2:10

It's still on the chest wall where it began life,

2:13

whereas already the left lima is off of the,

2:16

uh, chest wall already.

2:17

And then we're just following this lima down.

2:20

Um, every once in a while you get a little bit too much, uh,

2:22

blooming artifact, not in this case, but from a clip

2:24

and you just tend to ignore it.

2:26

There's not really any better way to, uh, handle that.

2:28

So we're just following this on axial

2:30

anatomy all the way down.

2:32

And soon it will join up with here it's going

2:35

with at least some branch of the, uh, LAD

2:38

and then the, the LAD, just kind

2:40

of small vessel Peter's out there near the apex.

2:43

Next thing I wanna do is look at the next graph.

2:45

So here's an aorta coronary Venus bypass graft. Looks good.

2:49

It kind of wraps over the aorta and comes all the way down.

2:52

It turns out that circumflex grafts almost never go onto the

2:56

circumflex proper, but rather the obtuse marginal

2:58

Branches. And so, um,

2:59

just we'll stick on the left side of the chest

3:01

for a moment and you can see here is the left main artery,

3:05

uh, left anterior descending, heavily diseased.

3:08

It's probably occluded

3:09

or will become occluded if you bypass it.

3:11

And so that's why that lima raft is patent

3:13

diminutive, but patent.

3:14

And then we're gonna follow the left main into the

3:18

circumflex artery, where as expected it's very diseased

3:23

and probably occluded right here.

3:25

And then if we follow these obtuse marginal branches, uh,

3:28

we see that the bypass graft does

3:30

touch down on to some of them.

3:32

So at least one. And you can have jumps to multiple grafts.

3:35

That's a non-dominant circumflex. Here is your distal RCA.

3:39

So let's trace that back up to its origin.

3:41

So there's the proximal RCA, I'm just using axials here.

3:44

Nothing crazy yet. Um, some disease

3:47

and there's gonna be at least some narrowing in the mid RCA,

3:49

um, but the vessel's not bypassed

3:51

or at least not bypassed anymore.

3:53

And that does give rise to A PDA.

3:56

Um, this one would've probably called an early branching PDA

3:59

because it comes off fairly high

4:01

and um, misses some of the base, which is fine.

4:05

And then the, um,

4:06

posterior left ventricular branch is probably,

4:09

uh, a second branch.

4:10

I'm having trouble finding it.

4:11

So it, it could be that that's secluded.

4:13

Maybe that was bypassed.

4:14

Another way to look at these cases, uh, would be to

4:19

say we wanna look at the bypass graft over onto

4:22

the obtuse marginal.

4:23

Well, you could just center your cursor on it, uh,

4:26

and then make sure you get a little angulation,

4:28

turn on some mip, and that's the way that the,

4:30

uh, catheter will see it.

4:32

So here's my venous bypass.

4:34

Uh, so aortic coronary saphenous graft,

4:37

and then there's an anastomosis onto this native

4:40

and heavily disease, probably occluded proximally, uh,

4:43

obtuse marginal, but then the rest of the vessel is fine.

4:46

Uh, you can do the same thing for your lima too.

4:47

So let's just do that real quick.

4:49

So there's my anastomosis,

4:51

but doing in this MIP view, a little bit of, uh, angulation.

4:55

So this ought to look very similar in the cath lab

4:57

where you see this like tenting up of the proximal LED.

5:01

Another way to look at right coronary arteries is to do

5:03

that kind of C shaped view.

5:05

So I might, uh, choose to center here,

5:10

do a little angling just

5:11

to really outline the artery course.

5:15

And so it looks patent to me.

5:17

I think maybe a moderate narrowing.

5:19

So not much more than between 50 and 70%.

5:23

So not the worst of all, uh, stenosis.

5:25

And let's see what the, uh,

5:27

anatomy looks like in the cath lab.

5:31

So they've done some pre-work

5:34

and this will be a, an attempt to cannulate the Lima graft.

5:39

It's hard and that's why clearing these

5:41

with a CT is very helpful.

5:43

They can opt not to look if we don't think we see disease.

5:45

So there's your Lima origin.

5:47

Um, things you might comment on

5:49

or if they're very centrally deviated, uh,

5:51

or if they're right behind the sternum.

5:53

'cause that's something if they do plan a repeat

5:55

surgery, uh, it's good to know.

5:57

So when you're sawing through the chest

5:58

that you're careful to avoid these.

6:00

So they laid this out nicely

6:02

and there's your touchdown with the, uh, LED

6:05

and you can see some competitive flow there from the

6:08

proximal vessels.

6:09

Uh, and then the wraparound LED.

6:12

And here's an attempt to look at the, uh,

6:15

left main antegrade difficult.

6:17

They finally did get in.

6:19

Um, and there is your

6:21

distal circumflex, so things look good.

6:25

We thought maybe a moderate RCA stenosis.

6:28

This is the left main. Again, you can see

6:30

that the distal circ does pacify.

6:32

Let's see how here's the right coronary artery

6:35

and just kind of a only moderate

6:38

lesion just right around there.

6:39

I'm gonna pause it for you. Just so you see there's disease

6:43

and the vessels do fill distal

6:45

of the PDA as well, a pass fight.

6:47

Uh, so in summary, a bypass graft from the arterial side

6:52

as well as a bypass graft from the venous side.

6:56

No right-sided grafts.

6:58

But the native RCA is not terribly stenotic.

7:01

This is a just a different, um, view

7:03

where things have segmented out by our 3D lab can just kind

7:06

of clean things up and remove the extraneous anatomy.

7:08

But a nice way to give an overview, um, before surgery.