Interactive Transcript
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Let's gild the lily, as we say,
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and look at a few more cases of carotid encasement
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to make sure that we understand the concepts.
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On the top left, we have a case of nasopharyngeal
0:12
carcinoma. This tumor is outlined as you see here,
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coming from the nasopharynx.
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When we look at the internal carotid artery,
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we see that there is less than 180 degrees of
0:27
involvement of the wall of the left internal carotid
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artery. Therefore, were this to be operated on,
0:35
this tumor should be able to be peeled off
0:38
of the internal carotid artery.
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Now,
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nasopharyngeal carcinoma is not a surgical tumor.
0:44
Nasopharyngeal carcinoma is treated with
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radiation therapy and chemotherapy.
0:49
And in this case, it's irrelevant because they're not
0:52
going to go in for the internal carotid artery.
0:54
Remember, however,
0:55
that radiation therapy can lead to vascular
1:00
inflammation and weakness in the wall of the
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internal carotid artery and could lead
1:05
to potential carotid blowout.
1:08
How about this case in the bottom right,
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this is an oropharyngeal cancer from
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the palatine tonsil. However,
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It has grown posteriorly and laterally to involve.
1:20
the carotid chief structures.
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Here's our normal internal carotid artery.
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Here's our normal internal jugular vein.
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Here is our carotid artery.
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Here, once again,
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we see that the tumor comes to the wall of the
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carotid artery but is involving less
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than 270 degrees of involvement.
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This tumor would be operated on, and it should be able
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to be peeled off of the internal carotid artery
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without causing it to have to be sacrificed.
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This is the 270-degree rule that was established
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in the article back in the 1980s.
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Contrast that with this case.
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So this is a very large tumor that has infiltrated
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not just the deep lobe of the parotid gland,
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but also the soft tissues laterally
2:10
in the right side of the neck.
2:12
If we look at the internal carotid artery in this
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case, despite the very large size of the lesion,
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the internal carotid artery wall is not involved
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greater than 270 degrees. And therefore,
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this very large tumor would be able to be peeled
2:30
off of the internal carotid artery.
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How about this case? Here we have another case.
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This was actually involving the soft palate
2:39
and growing into the posterior pharynx.
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But in this case,
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it seems as if the carotid artery is
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circumferentially involved. You might argue, well,
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how much is the normal width of the carotid wall?
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The carotid wall should be indistinguishable.
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Therefore, this small amount of tissue
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that is around the posterior lateral wall of the
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internal carotid artery can be presumed to be tumor.
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And therefore,
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this is 360 degrees of involvement of
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the carotid artery. And therefore,
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in this squamous cell carcinoma,
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this carotid artery cannot be salvaged.
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This is a primary tumor.
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This is nodal disease. Here, once again,
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we have the carotid artery with tissue which is
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encircling the carotid artery. Not 360 degrees,
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but very close to 360 degrees.
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I put it from here all the way around.
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You can see the nodal disease here,
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nearly 360 degrees.
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But greater than 270 degrees, this carotid
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artery would not be able to be salvaged.
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So again, treatment effect.
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Either they say this is nonsurgical disease,
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nonresectable disease, and treat
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with chemo and radiation,
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or they put up a balloon and occlude
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the internal carotid artery,
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see whether the patient is able to tolerate it
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without neurological symptoms and take the carotid
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artery at the time that they do the
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nodal dissection. In this case,
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the patient was treated with chemo radiation.
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