(G-tube) button mechanics

If you’re new to a tube, or perhaps considering switching from a ‘dangler’ tube to a button type, or even if you’ve had a button for ages, you may wonder exactly what that “anti-reflux” valve is, how it works, and how it fails.

I had an old MIC-KEY button on hand, and did a little surgery on it with my trusty x-acto knife, in order to get a look at this part of the button’s construction.    Previous to this, I’d searched several times online for an explanation of the anti-reflux valve mechanism, and could find nothing.  I found information and diagrams for all kinds of one way valves—tires for vehicles and garden hoses—but nothing that showed how the anti-reflux part of a g-button works.

According to my new gastroenterologist, all g-buttons have very similar technology, so even though there may be slight variation between the one I show, and one by Boston Scientific, or AMT—or any manufacturer you might use— the basics, as far as I can tell, are the same.

Because the button I am demonstrating with is a balloon type button, and you might be curious about that part too, I’ll show it without inflation as well as inflated.  The reason for the brown discoloration of the balloon is because it is used, and stomach acid turns all balloons brown eventually, even though they start out clear when newly placed.  Please overlook any  crusty stuff you happen to notice on parts of the button.  The photos are taken close up so you can see detail as well as possible, and  this button was used several years ago, and it unfortunately shows some old food residue.  (Yeah, yuck, but oh well.)

Here is the button, capped up like it would be when not in use for feeding.

I added water to the balloon using the fill port and a slip tip syringe

This next photo, below, shows a feeding extension set in place, like it would be for a meal.


I removed the feeding port from the button —not that easy to do! (The balloon is no longer inflated.)

The next photo shows the feeding port from the top side.  The anti-reflux ‘valve’ is merely a slit in a membrane of silicone that covers the tubular opening of the port.  It’s kind of hard to distinguish the slit (hence the black pointy hand)

The photo below shows the feeding port, and anti reflux valve (slit) from the underside.  It is much easier to make out what I’m trying to describe from this photo than the previous one.

The following photo shows the port from the underside again, the feeding extension set is in place exactly like it would be when used for feeding, and the membrane that works as an anti-reflux valve is  pierced by the tip of an extension feeding set.  Sorry about the photo being so off-center, I kept cropping because the rest of the g-button was visible in background, and made it a little confusing to look at.   You can see the circular tip of the extension set going through the slit in the silicone membrane.  (Just ignore that brown balloon you can see behind it, it is photo by accident and has nothing to do with what I’m showing.)


So, when people talk about the anti-reflux starting to fail on their button (or you experience this yourself)  what is happening is that slit is beginning to not close back together when the feed set is removed.  This will eventually happen with all g-buttons, regardless of manufacturer, however, it has been my experience (and that of many others, too)  that the AMT brand lasts quite a bit longer than the MIC-KEY  button, I don’t know if AMT uses  thicker silicone, or the silicone is a higher quality, or what, but they generally will outlast other brands.

With a balloon type g-button, there are two pieces of the equation for how long the button will last before it needs exchanged for a new one,  The balloon can fail (either gradually, or just bust to where it holds no water whatsoever) and, of course what most of this post has been about,  after time passes, eventually there will start to be some leakage when the extension set is removed after a meal, because that slit is not closing back together tightly.

I had one button (the Corflo cuBBy) which I actually loved for many reasons, but when that part of it started to fail, it FAILED!   As in even with the cap closed, I constantly had leakage seeping out and getting on my clothes.  Not a fashion statement, nor a good way to smell!

Even though it is not completely on topic for this post, I did want to mention that almost a year after it was first placed, I am still completely LOVING my AMT Capsule non balloon button.  Hands down the best I’ve ever had.  It is time to have it replaced, and my doctor retired (Noooo o o o!)  And it took a while to find a new group that would accept a patient with tube placed by another doctor.  I am scheduled for the exchange next month, and am thinking of asking if we can take a video the procedure.  If they agree, I will post it here on Tube Chic.

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