How does heart transplant surgery work? - Roni Shanoada

譯者: Wei C. 審譯者: Bruce Sung

Your heart beats more than 100,000 times a day.

你的心臟一天跳動超過十萬次

In just a minute, it pumps over five liters of blood throughout your body.

僅僅一分鐘內， 它抽送超過五公升的血液流過全身

But unlike skin and bones, the heart has a limited ability to repair itself.

但不像是皮膚與骨骼， 心臟的自我修復功能相當有限

So if this organ is severely damaged,

所以若是損傷太嚴重

there’s often only one medical solution: replacing it.

通常就只有一種醫治方法： 更換它

Today, nearly 3,500 heart transplants are performed each year

如今，一年內會執行 將近 3500 個心臟移植手術

in a complex and intricate procedure with no room for error.

這是道複雜且精密的程序， 絕不容許出錯

The process begins by testing potential recipients

過程開始首先會測試可能的接受者

to ensure they’re healthy enough for this demanding operation.

確保他們足夠健康 得以接受嚴苛的手術

Doctors are especially concerned with identifying immunocompromising illnesses

能辨認出免疫功能低下的疾病 對醫生而言十分重要

or any other conditions that could compromise a patient's chance of survival.

或是任何可能危及病患存活的病狀

The next step is to match an eligible recipient with a heart donor.

下一步便是將心臟捐贈者 配對到一個合格的接受者

Donors are often comatose patients with no chance of being resuscitated

捐贈者通常都是 沒有機會甦醒的昏迷病患

or victims of a fatal event whose hearts are still healthy.

或是經歷了致命事故 但有健康心臟的受害者

In both cases, these patients need to be registered as an organ donor

在這兩種情形之下， 這些病患須被登記為器官捐贈者

or have their families give consent.

或是取得其家人同意

And even when a heart is available,

即使有可用的心臟時

surgeons can’t just pair any donor with any recipient.

外科醫師也不能 隨意配對捐贈與接受者

The recipient’s immune system will view a transplanted heart

接受者的免疫系統會將移植的心臟

as a foreign organism that must be attacked.

視為外來有機體並對其發動攻擊

So doctors need to match recipients with donors that share their blood type

所以醫生必須將有相同血型

and have similar antigens.

和抗原的接受者配對

If a match can be made, the surgery can begin.

若配對成功， 手術便可開始進行

Once the donor's heart is confirmed to be healthy,

一旦確認了捐贈者心臟是健康的

the organ is immersed in an ice slush

器官會被埋進碎冰中

and injected with a solution to induce cardiac arrest.

並注入一種能引起心臟停搏的藥劑

These treatments stop the heart from pumping

這些步驟能讓心臟停止跳動

to ensure it can be removed cleanly.

以確保它能被乾淨地移除

Surgeons then place the organ in a mix of cold saline

外科醫生接著會把器官放入 冰生理食鹽水

and preservation solution.

與保存溶液的混合液中

This is when the clock starts.

這時候時間就十分寶貴了

Disconnected from its blood supply,

斷開心臟的血液供應後

the heart’s cells start taking on damage from lack of oxygen.

心肌細胞會開始因缺氧而受損

The organ will only remain viable outside the body for a few hours,

這個器官僅在體外的幾小時中存活

so it needs to reach its recipient as fast as possible.

所以必須越快送給接受者越好

Once the heart arrives, the recipient is put under general anesthesia.

一旦心臟送達， 接受者將接受全身麻醉

The surgeon makes an incision down the length of the chest,

外科醫生會沿胸腔做一個切口

cutting through the breastbone to separate the rib cage

切開胸骨並分離胸廓

and expose the heart.

然後暴露出心臟

To keep blood flowing while they remove the damaged organ,

為確保在移除受損器官時 能維持血流

surgeons use a cardiopulmonary bypass machine.

外科醫生會使用心肺體外循環機

This takes over the heart's job,

來接管心臟的工作

generating enough force to push blood through the patient's circulatory system.

產生足夠的力將血液

推送過病人全身的循環系統

After the old heart is removed,

當舊心臟被移除後

the surgeon begins sewing the donor heart into place.

外科醫生開始縫上捐贈的心臟

This is an incredibly precise process, where each blood vessel and artery

這是極度精密的過程， 每條血管與動脈

must be carefully attached to avoid leaks.

都必須小心的接合， 以避免溢漏

The procedure can last several hours,

手術過程會持續上數小時

potentially longer if there’s scar tissue from previous surgeries.

如果之前的手術產生疤痕組織 可能會花更久時間

Once it’s finished, the bypass machine is turned off

手術完成後， 體外循環機會關閉

and blood is allowed to flow into the aorta.

而血液便可開始流入主動脈

Doctors carefully monitor the new heart to ensure it’s beating on its own

醫生會小心地監控 確保新的心臟是靠自己跳動之後

before sewing the recipient back up.

才將接受者縫合

Even after the procedure is complete, there's still work to be done.

即使在手術完成之後， 還是有些工作待進行

Surgeons are unable to directly connect the heart

外科醫生無法直接將心臟

to the recipient’s nervous system,

連接到接受者的神經系統

and it can take years for the body to fully innervate the new organ.

故可能得花上數年 來使身體將器官完全接上神經

During this period, the transplanted organ has a higher resting heart rate

在這期間， 移植心臟會有較高的靜止心率

and risk of stroke, making exercise difficult and dangerous.

與中風的風險， 讓運動變得困難且危險

And since it’s incredibly rare to find a perfect match

而又因為在捐贈者與接受者之間

between donor and recipient,

找到完美匹配的器官非常罕見

the immune system will also have some response to the new heart.

免疫系統也會對新心臟做出反應

Immunosuppressive drugs can help manage the risk of rejection,

免疫抑制藥物可以降低排斥的風險

but they also leave patients open to contracting dangerous infections.

但也可能讓病患容易得到嚴重感染

It requires constant monitoring and testing to balance these two concerns.

這都需要持續的監測與檢查 來平衡兩者

Despite these challenges, about 70% of heart transplant recipients survive

儘管面臨許多挑戰， 有七成的心臟移植接受者

for at least five years after the operation,

在手術後至少五年內存活

and just over 20% live another 20 years.

而僅有超過兩成能再活 20 年

So when this procedure is successful, it's truly lifesaving.

所以當手術成功時， 確實是能救人一命

Unfortunately, people in developing countries are often unable

不幸地是， 生活在發展中國家的人

通常無法進行這種手術

to access this surgery,

and many viable hearts can’t be donated due to legal and regulatory issues.

因為法律規範問題， 眾多有效的心臟無法捐贈

Thousands of people remain on waiting lists,

數千人仍在等待名單上

and many are never able to find a suitable donor.

而許多人甚至無法找到 合適的捐贈者