Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
There is nothing wrong with putting veins from pigs into a person’s heart.
The late prominent Saudi Muslim scholar, Sheikh Ibn `Uthaymeen, stated:
There is nothing wrong with putting veins from pigs into a person’s heart. This is based on what is most suitable for his heart. Because this is not the matter of eating, and Allah has only forbidden eating pigs, and this is not eating.
Once we know that nothing else will help him except this, then it becomes the matter of necessity and Allah says with regard to eating pig meat, i.e., putting it directly in the mouth:
“…while He has explained to you in detail what is forbidden to you, except under compulsion of necessity.” (Al-An`am 6:119)
Almighty Allah knows best.
Source: https://islamqa.info/en/93212