I've noticed a lot of posts recently comparing and confusing ERNY revision procedures with BPD revision procedures, a component of the DS. Some people are under the impression that a Bilio-Pancreatic Diversion (BPD) is the same as an ERNY.
The summary statement: A BPD procedure - with or without a DS - is absolutely NOT the same thing as an ERNY.
From reading some of the posts here on OH, it seems that this confusion arises from the impression that the small intestine acts essentially the same along its entire length. In other words, that food, calories, and nutrients are absorbed the same way no matter where in the small intestine the food happens to be passing at the time. In fact, different parts of the intestine handle nutrients in different ways. Different parts of the intestine will produce different hormones and metabolic signals in response to food passing through it. The chief example of this is the "neuro-endocrine brake" effect, the main metabolic effect of BPD/DS. Food passing through the upstream portion of the intestine fosters the deposition of fat within the body, where the same food passing through the downstream portion of the intestine has just the opposite effect. Moving this downstream intestine further upstream - as is done in BPD/DS - creates the "neuro-endocrine brake" effect. Our understanding of this effect dates back to the original work on "Ileal Transposition" dating back to the 1980's.
In an ERNY, no such re-arrangement of the downstream intestine occurs. The upstream intestine is simply moved further downstream; the upstream intestins remains attached to the stomach pouch. The total length of intestine is reduced - theoretically reducing absorption - but no increased metabolic effect occurs (in fact, it should - at least in theory - decrease the neuro-endocrine effect).
It appears that some of this confusion arose from posts discussing revision from RNY to DS. I am a great advocate of the DS, and it constitutes the bulk of my practice. It is the most metabolically active and most durabl procedure available for weight loss and reduction of co-morbidities. My goal when evaluating patients for revision from failed RNY is to get them to the endpoints of a DS procedure. Those three endpoints are restriction, malabsorption, and metabolic effect. The malabsorption and metabolic effect of a DS can only be accomplished by the Bilio-Pancreatic Diversion portion of the DS. Many patients, though, are already eating through their RNY pouches like a DS patient should. In these select patients, no further work on the stomach is necessary to get them to a DS lifestyle, in my opinion. For patients with dysfunctional RNY pouches, however, conversion to a full DS - or at least a Vertical Sleeve Gastrectomy - is necessary to get them to a more functional state. What is important is that, in the end, the patient have the proper combination of malabsorption, metabolic effect, and restriction, whether or not that restiction involves converting the RNY pouch to a Sleeve or not.
John D Husted, MD
Dr. John Husted
DISCLAIMER: I am not your surgeon, any comments made by me are not meant to be taken as medical advice, just general guidelines. Contact your surgeon about your specific problem!