Recently a youtuber died of a thrombotic stroke a week after a lung transplant operation. Skimming over abstracts on Pubmed, it appears that strokes and more generally thrombosis is a frequent complication.
However, these articles, which spans a little over a couple decades, stuck to estimating the frequency of these complications and didn't explore potential causes. The closest was one that found statistically significant risk factors like old age and cardiovascular disease (duh), but that isn't really a detailed mechanism and didn't seem relevant to the youtuber in question (she was 21 years old).
Is there an explanation for lung transplants causing strokes so well-known that it's not worth mentioning in research, or is this really unknown?