Marfan Syndrome Management: Back to Basic
13:18-16:30
So I'm going to go a little more into the difference between an aneurysm, a rupture, and a dissection, so just looking at this. This is a diagram of the body so as I mentioned here's the heart. This candy cane-shaped looking vessel is the aorta and the aorta gives off blood to the arms, the brain, back down to the body to the kidneys and back down to the legs. You can see it's really important
では大動脈瘤、大動脈破裂、大動脈解離の違いについて見ていきましょう。こちらは全身の図です。ここに心臓があり、そこから大動脈が出て、腕、脳、腎臓、脚などに血液を送ります。ご覧のように大動脈は非常に重要な役割を果たしています。
Now an aneurysm just means that part of this aorta is dilated so this is called an aortic root aneurysm. This is called an ascending aortic aneurysm, just depending on the location. This has no pain, it has no symptoms. This is only picked up by imaging. You can only get it by an echo or a CT or a MRI. It doesn't cause any symptoms at all but just gets progressively larger. It just is this ballooning out.
大動脈瘤とは、大動脈の一部が拡張することです。できた場所によって呼び方が異なり、(a)を大動脈基部の大動脈瘤、(b)を上行大動脈の大動脈瘤といいます。動脈瘤ができても痛みや自覚症状はなく、エコー検査やCT、MRIなどの画像検査でのみ発見が可能です。症状はなくとも徐々に膨らんでいきます。
Now a dissection is where there is a tear in this wall so if you look, if you took a cross-section of this aorta the aorta actually has three layer, three muscular layers. There's this intima, the, the media, the intima, and the adventitia and basically if there's a tear of one or two of the layers they can bleed into the wall and so the outside layer gets separated so you get sort of this we call it a false lumen and blood comes out here. This is a dissection. This blood is dissecting down the vessel here and can cause clotting in this area, can cause this wall to come in and compromise blood flow to wherever the blood is trying to get to to the legs, to the kidneys, to the brain, to the arms and so and this is quite painful so an aortic, when people say, "Oh, I, I had pain from my aortic aneurysm," that's really rare but pain from an aortic dissection is almost universal this is a quite painful thing to happen and so it gives these passages for blood. Now when it happens in a very small vessel like a vertebral artery, which is a small vessel off the aorta to brain, sometimes that doesn't cause significant pain and might go unnoticed but an aortic dissection will not go unnoticed because that's the largest vessel in the heart.
大動脈解離は大動脈の壁が裂ける病気です。こちらの大動脈の断面を見ればわかりますが、大動脈は3種類の筋層から成ります。内側の層を内膜、真ん中が中膜、外側が外膜です。内膜あるいは中膜が裂けると、血液が大動脈壁内に流れ込み、外側の層を剥がしていきます。この時にできるこちらの空間を偽腔と呼びます。血液は偽腔を流れることになります。血流は大動脈の層を剥がしながら下り、血栓をつくったり、剥がした壁を巻き込んで元の血流に合流することもあり得ます。その結果、脚や腎臓、脳や腕などに向かう血管を塞ぐことがあります。大動脈解離は激痛を伴います。大動脈瘤による痛みが出ることは非常に稀ですが、大動脈解離では血液の別の通り道ができますので、ほぼ確実に痛みが出ます。脳へ向かう椎骨動脈などの非常に細い血管で解離が起きた時はそれほど痛みが出ず、自覚されないこともありますが、最も太い大動脈で解離が起きた場合に気づかないということはあり得ません。
Now a rupture is different than both of those. A rupture is when the whole wall tears through so not it doesn't bleed into the wall of the aorta but bleeds into the thoracic cavity into the chest and so this allows blood to leave this. Now this is a huge vessel. This is pumping blood so this is almost universally lethal unless you're in the middle of an operating room when you actually have a rupture but thankfully a dissection is more common than a rupture but this is what we worry about as well.
大動脈破裂は先ほど説明した2つの疾患とは異なり、大動脈の壁が完全に裂けて、そこから胸腔内に血液が流れ込みます。血液を送り出す太い血管から血液が出ていくことになりますので、手術中に大動脈が破裂した場合を除けば、ほぼ助かりません。幸い、破裂は解離よりも発生頻度は低いのですが、やはり注意が必要です。
So there are certain dissection types and I'm sure that we're going to hear more about that in the second half but dissection types in general we look at this is called a Stanford type A or a Debakey I and II and this is the most common this is when there's a tear up right near this aortic root I told you about or the ascending aorta and sometimes this can propagate and dissect all the way down but it means it started somewhere here or earlier. Then you can have a type B, a Stanford type B dissection and that's where the tear happens more prop, distal in the aorta past this area. This is a different kind of type B dissection but where it's happening further along in the aorta.
大動脈解離の分類法についてですが、後半に書かれている分類法については皆さんご存知かと思います。一番左はスタンフォードA型あるいはDebakey I/II型と呼ばれているものです。大動脈基部あるいは上行大動脈で解離が起きた場合です。ここを起点として下流まで解離が続くこともありますが、解離の開始位置が心臓に近い場合には、この分類になります。真ん中の大動脈解離B型（スタンフォードB型）は弓部で解離が起きる場合で、一番右とは違うタイプですが、解離は先まで進行します。
And the this type almost universally gets emergency surgery and these type, it really depends on what the symptoms and where it is and what systems are getting compromised but they don't always have to have surgery.
スタンフォードA型では、ほぼ間違いなく緊急手術が必要となりますが、スタンフォードB型は自覚症状や起きた場所、機能不全となっている臓器の系統によって、手術が必要かどうかが決まります。
The Marfan Foundation did not participate in the translation of these materials and does not in any way endorse them. If you are interested in this topic, please refer to our website, Marfan.org, for materials approved by our Professional Advisory Board.
The Marfan Foundation は、当翻訳には関与しておらず、翻訳内容に関してはいかなる承認も行っておりません。このトピックに興味をお持ちの方は、Marfan.org にアクセスし、当協会の専門家から成る諮問委員会が承認した内容をご参照ください。
