0:01

This next case, um, is a patient also with rectal

0:04

cancer, and the question is staging of the tumor.

0:08

And so, I'm going to show you

0:10

two cases, uh, in succession.

0:12

The point of these two cases is basically

0:15

how do you deal with low rectal cancer.

0:17

We mentioned a few points in the earlier

0:19

case with mucinous pathology, but in terms of

0:23

rectal cancers that actually extend way down into

0:26

the anal canal, there are a couple of pointers

0:29

that you need to keep in mind and mention.

0:32

Before we start looking at the cases, just to lay

0:35

the groundwork, there are sort of two, three, or

0:37

four key points that you need to pay attention

0:39

to when you're talking about low rectal cancers.

0:42

First of all, as I mentioned, I need to reemphasize

0:44

that you need to be absolutely certain that this

0:47

is beyond any reasonable doubt a biopsy-proven

0:49

rectal cancer and not an anal cancer.

0:53

And because, as I mentioned earlier,

0:54

we cannot distinguish the two.

0:56

So that's the first point.

0:58

The second point is for low rectal

1:00

cancers that extend into the anal canal.

1:04

There is no concept about distance to the

1:06

mesorectal fascia because there is no mesorectal

1:09

fascia that you can identify in this location.

1:12

And so, if it is at the level of the levator or

1:15

the puborectalis, you give the shortest distance

1:18

to the levator ani or to the puborectalis.

1:21

If it extends below the level of the puborectalis

1:24

into the anal canal, then you need to talk about

1:28

whether there is involvement of three structures.

1:31

And the three structures in succession are:

1:34

Is there involvement of the internal anal sphincter?

1:37

As I mentioned early on when we talked

1:39

about anatomy, it is a little bit

1:40

brighter than the external sphincter.

1:43

Is there involvement of the intersphincteric

1:45

space, which is this bright space containing

1:48

fat between the internal and external sphincter?

1:51

And is there involvement of the

1:52

external sphincter and beyond that?

1:55

Now, why do we try to make the distinction?

1:57

Because if the tumor is confined

1:59

to the internal sphincter, you can

2:01

still do a sphincter-sparing surgery.

2:05

But once it goes into the intersphincteric space

2:07

or the external sphincter, then these patients

2:09

have to have their sphincters taken, and these

2:13

patients typically end up having a colostomy.

2:16

So that's sort of the three key points you need to

2:19

keep in mind when you're looking at low rectal cancers.