0:00

So here is our 63-year-old man

0:04

who's had lumbar surgery

0:06

and now has severe right greater than left leg pain.

0:11

And I would urge you to go back and look at

0:14

our introduction to spine lumbar surgery,

0:17

because if you don't understand

0:19

what the procedures are about,

0:20

you're not going to be able to

0:21

figure out what's wrong.

0:23

And that was beautifully articulated by

0:26

my neurosurgical colleague, Dr. Schupeck,

0:28

in that vignette.

0:29

So this patient has an obvious huge complex septated

0:34

fluid collection in the soft tissues and involving the

0:38

extradural space. And if you scroll very carefully,

0:41

it's compressing the thecal sac,

0:43

pushing it to the left and the poor nerve roots on

0:46

the right side. We're down here at L5-S1.

0:48

Where are they? Well,

0:49

maybe that's one right there that's just getting

0:51

completely squished. Let's go up to L4-L5.

0:55

Things don't look all that much better at L4-L5.

0:58

There's a nerve root right there,

1:00

and that thing is also getting heavily squished.

1:03

We've got the thecal sac that is intermeshed actually,

1:08

here's the thecal sac. Sorry, there's the thecal sac.

1:11

And it's markedly compressed forward,

1:13

almost completely effaced by this

1:16

complex fluid collection,

1:17

which we now know from the historical

1:19

information and from research,

1:21

was a seroma hematoma that got evacuated.

1:25

And maybe they didn't evacuate it so much, did they?

1:29

Because there are some high signal foci inside and

1:33

some sort of wax on, wax off areas of high signal,

1:36

like this one right here.

1:37

So there probably is some dilute blood inside this

1:40

thing and that's why it has this heterogeneous

1:43

character to it. Now,

1:44

this happened pretty quickly after the procedure and

1:47

when you were looking at short-term complications

1:49

after surgery. The big ones are wrong level,

1:53

the instruments have been placed in the wrong place,

1:55

or you've got some kind of weird fluid collection.

1:58

This falls into category number three,

2:00

the weird fluid collection.

2:03

So what's our differential diagnosis of the fluid

2:06

collection? We got a hematoma, we got a seroma,

2:10

we've got both, in this case, hematoma and seroma.

2:14

What would be something else that you would consider?

2:16

Well,

2:16

the other question when you see fluid in the epidural

2:19

space after surgery is, is there a fistula?

2:22

Meaning was there a CSF leak at the time of surgery?

2:26

Now, this is a pretty big one,

2:27

although we got a couple of outrageous-looking CSF

2:31

fistulas, but that could be contributing to it.

2:35

Okay.

2:35

And that would be something that if

2:37

you saw it would be important,

2:38

meaning you would handle that differently.

2:40

Meaning if you want to go in and say,

2:43

this guy needs to be decompressed, go in seroma,

2:47

but in your second awake, well,

2:49

you're going to do it a little bit differently

2:51

if you think you could be running into roots,

2:53

meaning if you think the dura is thin, okay?

2:55

So if you see that finding or have reason

2:58

to believe that's a possibility.

2:59

That will change how the surgery is done.

3:02

Right. So for this thing, I mean,

3:03

you just evacuate this thing.

3:05

Well, that's the goal. I mean,

3:06

it's a compressive lesion.

3:08

It's a symptomatic compressive lesion.

3:10

Patient's got leg pain. Patients got severe pain.

3:13

So something's going to have to be done here.

3:14

But if it was a communicating fistula with a dural leak,

3:18

then you wouldn't want to be sucking that out,

3:19

because then you're just going to be sucking

3:21

CSF out with it. Well, obviously,

3:23

you have to decompress the sac back.

3:25

But if you know that you could have in the bottom of

3:28

this thing that you're sucking out that there could

3:30

be nerve roots hanging around in there,

3:31

you're going to handle it a little bit differently.

3:33

In fact,

3:34

what you're going to do is you're going to probably do

3:36

a bigger exposure, go above it, get to normal dura,

3:39

and then follow the normal dura down into this area.

3:43

That's correct. Go from normal to abnormal.

3:48

Okay. Come up here.

3:49

Meaning if I thought this might be a fistula.

3:52

So someplace in here, there's a leak,

3:54

but I don't know where it is,

3:55

and it's got hematoma and everything around it.

3:57

I got to find normal dura either above and below,

4:00

find the dural sac,

4:01

and then follow the sac in so that I can kind

4:04

of sneak up on that hole and control it

4:10

instead of putting a socket in there.

4:13

Yes, that's correct.

4:14

That is the accepted treatment for

4:17

CSF leak is direct suture.

4:20

Now,

4:20

the problem is direct suture can be pretty

4:23

hard because the dura is often very thin,

4:25

particularly in a stenosis case.

4:26

And you're going to see a lot

4:28

more CSF leaks these days.

4:30

And the reason is because of this mis that

4:32

is this minimally invasive surgery,

4:34

they go through something this big.

4:35

Yeah. Right.

4:35

You're going through a 16 millimeter tube.

4:38

Right. How do you get it to sew this thing?

4:41

Now,

4:41

I just saw an instrument that has been developed

4:44

that allows you to put a suture in.

4:46

You can get these Castro Viejo things.

4:48

I've done it. It's a nuisance.

4:51

But like that, we would use on an ECIC bypass.

4:54

So it can be done.

4:55

And that is the standard unless you've oversown it,

4:58

that is the standard of care.

5:00

But a lot of times it's not,

5:01

because it's really not technically possible.

5:03

So people put gel foam,

5:04

they put some tissue sealant and stuff, and actually,

5:08

in mis,

5:08

it works reasonably well because you

5:10

don't have that much dead space.

5:11

Let me ask you a question from

5:12

the radiologic standpoint.

5:14

Is it helpful for you if we are able to localize

5:17

the leak, the site of the leak?

5:19

If we said, okay, the leak is right there,

5:21

is that helpful to you as a surgeon?

5:23

Yeah, it's very helpful. On the other hand,

5:25

you have to go in with the assumption that that may be

5:28

where it is, and there may be more than one okay,

5:31

so at least you know where to start.

5:33

Meaning I would start and find that,

5:35

but that doesn't mean okay, once I found that,

5:37

I'm done.

5:39

Because you might not see it.

5:41

Because once the sac is compressed,

5:43

you could have holes, areas that are tamponaded.

5:46

So after you start decompressing,

5:48

you could leak from be leaking from so it could

5:50

be complicated. So what you're saying is,

5:51

as radiologists, we may see the main leak,

5:53

but there may be other leaks present,

5:55

and we should be prepared for that?

5:56

Well, right, but also,

5:57

you've documented there is a leak.

5:59

Okay. Meaning if you can say for sure, no,

6:01

there's no leak, okay. Then it's a little easier.

6:05

You feel a little better about it.

6:06

Now, that might be a very hard statement to make,

6:09

but if you think there may very well be a leak,

6:11

you're going to handle this case a little differently.

6:13

Okay,

6:14

a couple of other points before we quit on this case.

6:17

There are some features here that

6:19

tell you it's not a leak.

6:20

Other than the fact that we already know it was a

6:22

hemorrhagic seroma or a hematoma that got evacuated,

6:25

it kind of helps to know the pathology.

6:27

But the very fact that it doesn't dissect around

6:30

in front of the fecal sac, that's a sign.

6:32

The fact that we actually don't see communication

6:35

between the dura and the collection.

6:38

So if I blow it up,

6:39

you've got this plane of separation on every single

6:42

slice. So there's no actual sinus tract.

6:45

That's a useful sign.

6:46

A third sign is the fact that we don't see signs

6:49

of intradural hypotension. In other words,

6:52

the veins aren't big. That's a good sign.

6:55

The fact that the patient has back pain but doesn't

6:57

have headaches or postural headaches,

6:59

that's another helpful sign.

7:01

So one of the most important things that you can do in

7:04

a case like this is make sure you differentiate a

7:08

collection that is separate from the intradural

7:11

contents from a duralik. And finally,

7:15

the last thing is and you mentioned it's so important,

7:18

you got to be sure there aren't any nerve roots

7:20

in this thing. And with that, we'll stop.