I suppose it's possible at that point, possibly to try and stem the process. The question is just how rapidly this condition emerges, and I suspect (although this is just a suspicion) that the time between onset and a severe reaction is fairly brief. Mostly though the problem is that this is a really complex, whole immune system reaction that's triggered by the AAV in the liver, but simply removing the intial cause probably wouldn't stop the cascade.

I took a look at some of the aftermath reports (i.e. https://pmc.ncbi.nlm.nih.gov/articles/PMC10638066/ and some others) which get into specific details about the course of treatment in several patients who died from this complication. The through-line is an aggressive use of several immune suppressing and modulating therapies to calm the cascade.

I have to admit I can't find any specific discussion about dialysis in that context, so I can only assume that removal of the viral particles would be a case of closing the barn door after the horse escaped.

My bad, snark wasn't my intent. I meant it literally. There was an accumulation of toxins, and it seems (to me at least) extremely unlikely that the researchers were not aware of dialysis as a way to remove toxins. So then let's jump to the next level of question.