The issue fundamentally limits the suitability of adult hearts being placed into young child recipients, differing entirely from liver transplantation. Student Xie's assertion about technical limitations is exemplified again here.
For example, when the donor heart is placed into the recipient, the donor's large blood vessels are thicker than those of the recipient, especially when the large diameter donor's arteries meet the recipient's small diameter arteries. It's not simply about a large diameter rubber tube being forcibly stitched to a small diameter rubber segment.
One should think about how the large diameter rubber tube is connected to a pump multiple times more powerful than the original, thus becoming a small pipe forced to link with a high-pressure water gun. Surely, this small blood vessel fears being burst by high-volume blood flow at any moment.
