A duodenal-jejunal bypass liner, commonly called an EndoBarrier, is an implantable
medical device
A medical device is any device intended to be used for medical purposes. Significant potential for hazards are inherent when using a device for medical purposes and thus medical devices must be proved safe and effective with reasonable assura ...
in the form of a thin flexible 60 cm-long tube that creates a physical barrier between ingested food and the
duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine m ...
/ proximal jejunum. The duodenal-jejunal bypass liner prevents the interaction of food with enzymes and hormones in the proximal intestine to treat
type 2 diabetes
Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, ...
and
obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...
. The duodenal-jejunal bypass liner is delivered
endoscopically
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...
and has been tested on the morbidly obese (those with a
body mass index
Body mass index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and he ...
MIgreater than 40) as well as obese patients with a BMI less than 40, particularly those with difficult-to-manage type 2 diabetes. Despite a handful of serious adverse events such as gastrointestinal bleeding, abdominal pain, and device migration — all resolved with device removal — initial clinical trials have produced promising results in the treatment's ability to improve weight loss and
glucose homeostasis
Blood sugar regulation is the process by which the levels of blood sugar, primarily glucose, are maintained by the body within a narrow range. This tight regulation is referred to as glucose homeostasis. Insulin, which lowers blood sugar, and ...
outcomes.
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How it works
The device is connected at one end to the beginning of the duodenum (first portion of the small intestine from the stomach) and at the other the mid-jejunum (the secondary stage of the small intestine). A
nitinol
Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel; e.g., Nitinol 55 and ...
anchor secures the bag at the duodenum, ensuring the liner doesn't migrate and that the
chyme
Chyme or chymus (; from Greek χυμός ''khymos'', "juice") is the semi-fluid mass of partly digested food that is expelled by a person's stomach, through the pyloric valve, into the duodenumbiliopancreatic portion of Roux en-Y gastric bypass (RYGB) surgery. This reduces the amount of calories absorbed and causes bile and pancreatic fluids to be redistributed later in the mid-jejunum for reduced breakdown and absorption of the chyme.
Initial clinical research by Rubino ''et al.'' in 2006 produced two hypotheses for why duodenal-jejunal bypass is effective in improving glucose homeostasis. Their "hindgut hypothesis" claims that by expediting the delivery of chyme to the distal intestine, the secretion of the gut hormone
GLP-1
Glucagon-like peptide-1 (GLP-1) is a 30- or 31-amino-acid-long peptide hormone deriving from the tissue-specific posttranslational processing of the proglucagon peptide. It is produced and secreted by intestinal enteroendocrine L-cells and certa ...
and glucose-dependent insulin is more effectively promoted, improving glucose metabolism. The "foregut hypothesis," on the other hand, states that by bypassing the duodenum and proximal jejunum (the initial parts of the small intestine), the inhibiting hormone GIP is secreted less, resulting in improved glucose tolerance. , those hypotheses continue to be tested, with Xiong ''et al.'' finding elements of both being involved.