I'm not an expert, but I think there's been a variety of attempts for vascular renormalization--to restore the normal flow of vessels to allow for drug delivery, etc. Rakesh Jain's lab (at MGH) is a big player in this field and is worth looking up if you're interested.

I'm not personally familiar with work in developing capillary devices, but it wouldn't surprise me at all if this was an approach under development--it certainly makes a lot of sense.