The Mini Gastric Bypass is a restrictive and malabsorptive procedure.  Restriction is accomplished by surgically altering the stomach so it is smaller.  It is cut to divide the upper stomach from the lower.  Malabsorption is accomplished because the intestinal tract is looped upward and attached to the  upper stomach (or pouch). This procedure, first used in the late 1960’s and abandoned in the 1970’s,was recently brought back because this operation can be done through a laparoscope. This operation is very similar to the Roux en Y procedure.  It functions by dividing the stomach into a small, one-ounce or less, upper pouch from the remainder of the stomach.

Mini Gastric Bypass Surgery stomach cutsThe upper pouch empties directly into the small bowel.  No part of the stomach is removed.  It is cut and clipped to form a thin tube, which is reconnected, bypassing about six feet of intestine.  The procedure is considered permanent, and would only be changed if a medical problem arises that requires the body to absorb more nutrients.  The American Society of Bariatric Surgery does not endorse this procedure because their are other surgeries that are safer and more effective.

How to make a mini gastric bypass

Gastric bypass with loop gastojejunostomy

We bring a loop of small bowel up to the stomach, making an opening between them in order for food to move out of the pouch and into the bowel. This opening between the stomach and the small bowel is called an “anastomosis.” That is it—you have now done an operation! Experienced surgeons can do this procedure in about twenty minutes. The short operation time is one of the advantages touted for this procedure.

Gastric bypass with lesser curve pouch and Roux-en-y

Now compare the mini gastric bypass to the more popular Roux en Y procedure. See the difference? No? There is an extra connection in the RNY that prevents the lower content from going to the upper pouch.

Why that extra anastomosis (connection)? In normal anatomy (that is anatomy which God gave you, before some surgeon decided to mix it up) the end of the stomach is marked by the pylorus—or, a type of one-way valve that helps keep digestive juices out.

Roux en Y gastric bypass – stomach pouch – Pylorus Bile duct – Common Channel

Food moves from the pouch into the small bowel, (A) which is known as the enteric limb.  The digestive juices are carried by the small bowel (B) known as the bilio-pancreatic limb. They join together at C, which is called the “common channel.”

The R.N.Y. procedure separates these components of digestion.  The RNY brings digestive juices away from the pouch, avoiding irritation by these juices.Mini-gastric bypass surgery showing how digestive juices flow back into the stomach

However, as you see in the Mini gastric bypass, those digestive juices, the bile, the enzymes, all flow back into the upper pouch. Normally they aren’t there. Critics of this procedure state that those juices can cause some erosion there (bile gastritis) and the esophagus.

Mini-gastric and Roux en Y bypass surgeries

The question remains—is the procedure that bad?

It is not supported by The American Society of Bariatric Surgeons, nor by a number of insurance companies, but it is fast and it does have the components of the Roux en Y.  The extra connection, the Roux en Y, serves as protection to the pouch, keeping the bile and enzymes away from it.  That extra connection takes some extra time to create and is one extra connection that can leak—although it is rare.  The most common connections that leak are the ones between the stomach and the small bowel.

In summary, the mini-gastric bypass was the first of it’s kind

It was largely abandoned because sometimes the bile and pancreatic juices caused damage to the lining of the pouch and esophagus.  When bile refluxes back into the pouch it can cause damage, pain, and ulcers.  This procedure does work. The question is whether this is a better procedure than the RNY.  The answer is that it is not better.  The RNY takes a bit longer to do, but not that much longer.  Sometimes it is worth spending an hour or so more in the operating room in order to avoid future problems.  Proponents of this operation say that it works as well as the RNY, and that these concerns are minimal.