Sizing of the esophagus during MSA placement is one of the most critical components of this procedure. Experience and some limited data have taught us that sizing the device more tightly around the esophagus appears to result in more dysphagia and possibly an increased erosion rate. On the other hand, sizing slightly looser in a non-compressive manner does not appear to compromise reflux control. Theoretically the appropriate size is one that is non-compressive around the esophagus. Practically this can be difficult to determine.
Various ways to size include:
(1) simple visual inspection for the first evidence of compression during closure and then go one size
(2) rotating the shaft at each size and looking for movement on the white loop up-down the esophagus.
When there is no movement then go one size up;
(3) close the sizer until the magnetic tip pops-off then sizing up 2 or 3 beads.
The key to (1) and (2) is corroborating that the part of the sizing shaft that goes behind the esophagus is just in contact with the esophagus. The Pop Off method (3) should be limited to a confirmatory method to further verify the visual cue method. The limit to the pop-off method is that popping off measures the compressibility of the esophagus, and that compressibility can vary.
On behalf of the American Foregut Society and the European Foregut Society
John Lipham and Sebastian Schoppmann
Note: This expert recommendation was worked out at an international expert meeting for treatment of GERD 2021 in Vienna.