hi let's talk about the veins of the posterior mediastinum as you may recall much of the thoracic
wall is drained via the azygos system the azygos system is a series of unpaired veins and we have
the azygos vein draining into the superior vena cava and that azygos vein is going to
drain intercostal spaces 2 3 4 5 6 7 8 9 10 11 on the right side as well as the subcostal vein
as well as the ascending lumbar vein and then on the left side we're going to have the accessory
hemiazygos vein as well as the hemi azicus vein
draining the left intercostal spaces but we can only see the right side here and so let me trace
this for you here's the arch of the asagas vein and it's descending down here and all the way down
here it is coming down down down and here are those posterior intercostal veins
on the right side draining into the aziz vein as we can see
um the accessory hemiazygos and hemiazygos are going to route underneath the esophagus and aorta
so let's take a look at the left side so that we may see these and just so we understand
what's going on there is a retractor here that's elevating both the aorta as well as the esophagus
and that is revealing to us that azygos vein here and so there are going to be two major tributaries
here is the accessory hemiazygos vein or the aha vein that accessory hemiazygos vein
will be draining intercostal spaces five through eight and then here is the hemi
azigus vein the ha vein that's going to be draining intercostal spaces nine through eleven
as well as the subcostal vein on the left side as well as the ascending lumbar vein on the left side
these veins are quite variable and so if your donor doesn't precisely look like this please
don't worry i've seen all sorts of permutations and i i think that it's just as likely that
you'll see this pattern as not see this pattern so one other treat for us as we look here this is
typically nestled between the azygos vein and the esophagus but i'll outline one margin of it here
this is the thoracic duct this is the major lymphatic channel of the body and it's beginning
at the cisterna kylie in the abdominal retroperitoneal space and it's ascending
superiorly in the posterior mediastinum it's more right lateral nestled between the esophagus
in the azikis and then about at the level of the thoracic plane it's going to abruptly change sides
it's going to switch from right lateral to left lateral where it will ascend through
the superior mediastinum posterior to the subclavian artery and it will wrap around
and insert itself ultimately in the vicinity of the left venous angle
it will return lymph from the entire body with the exception of the right thorax the
right upper limb and the right half of the head and neck to that left venous angle
so we've talked about the azia system and the thoracic duct thank you very much for your time