I'm guessing a difference in surgeon's technique, maybe? When my surgeon explained how he would do the procedure, he said he takes some of the stomach below the band and brings it up over and attaches it to the stomach, basically encasing the band in a little pouch, which he said keeps the band from being able to move. This maybe isn't standard?

I had a hard time describing this, here's my even rougher visual. The green marks are staples/stitches/whatever used to attach the stomach to itself. The stomach would cover all the way around, not just two points like I've shown.

I THINK it's just one stitch on the front side, but not over the band buckle. This reduces slips to the front (anterior?) but not to the back (posterior?) You are faster at this 'puter stuff than I am...try a Search on anterior and posterior and see what pops up...I'm betting there's a good link in here somewhere.

So I just did some research on this, because the picture my surgeon showed me was nothing like Wheetsin's, hehe.

I found the coolest article! http://www.ricercaecura.it/cont/1640app/0505/0300/11426all1.pdf

I'll attach a pic I got from there... I modified it a little (added labels). My understanding of things:

1. Originally they didn't stitch the lower stomach to anything to keep the band in place.

2. Currently most surgeons do the upper stitching (I believe the greater curvature is stitched to itself, or possibly another muscle, "over" the band -- creating a sort of belt loop)

3. This study was discussing the merits of stitching the lesser curvature also (to the right crus... part of the diaphragm)... it appears from browsing that some surgeons do this, some don't.

Slippage can occur when any of the many stitches comes out, or was too loose, or wasn't done at all. It can occur anteriorly or posteriorly.

Disclaimer: I'm not a doctor, lol, I just read a bunch of pages today.