I know there is a type of catheter available which is intended to compress esophageal bleeding.
It looks like a normal gastric catheter, though slightly wider. Also, at the exterior end, it has about 5 ports to inject air.
Once the air has been injected into a port, a section of the caterer expands, looking rather like the sausage shaped balloons that clown use to entertain kids at parties.
It certainly isn't the sort of thing that would be available to the general public, but the principal and therefore the blue prints will exist.
If you could redesign this idea, you might get an engineer who works with synthetic rubber to make a suitable device. It would need to be fairly stiff. It could be quite thin, since only one balloon would be needed. The amount of expansion is, of course, controlled by the amount of air injected, though warm water could easily be put in as an alternative.
adition. It has occured to me that three baloons would be even more useful. That way the expansion could be adjusted to different levels, concentrating on those areas most needed. Just a thought though. The extra baloon would mean widening the diametre. But even with the 5 port model used for esophageal bleeding, the width of the catheter is only about 8 mm
Further adition.
I found these, which are what I'm referring to. I'm not entirely certain if these are the type that open into a small, round baloon, or the long sausage type. But the name is what I was looking for.
I apologise if my descriptions are a little vague. It was almost 30 years ago, since I worked in a medical ward for any length of time.
http://www.nextag.com/esophageal-bougies/compare-htmlAnd another.
Sorry to be a pest, but I found this.
http://en.wikipedia.org/wiki/Esophageal_dilatationThe item is generally called Esophageal Bougies