Table of Contents
- What is a Roux-en-Y?
- Steps to Creating a Roux-en-Y
- How does a Roux-en-Y work in Bariatric Surgery?
- Which Bariatric Procedures Use a Roux-en-Y Small Intestinal Connection?
- What is a Loop Small Intestinal Connection?
- Steps to Creating a Loop Small Intestinal Connection
- How does a Loop Small Intestinal Connection work in Bariatric Surgery?
- Which Bariatric Procedures Use a Roux-en-Y Small Intestinal Connection?
What is a Roux-en-Y?
Roux-en-Y is a surgical reconfiguring of the small intestine to drain another organ. It involves two gastrointestinal tract connections to configure and diagrammatically resembles the letter “Y.” It was first described by Dr. Cesar Roux, a Swiss surgeon (1857-1934). The roux-en-Y configuration has been used to drain the stomach, pancreas, liver, and other gastrointestinal tract abnormalities. In bariatric surgery, the roux-en-Y is used to drain a portion of the stomach or small intestine.
Reference
Roux Operation
Steps to Creating a Roux-en-Y
Description of steps shown in picture above
- Shows normal gastrointestinal tract anatomy before surgical manipulation.
- A location along the gastrointestinal tract is stapled and divided as shown by the red dotted line creating a proximal (closer to the beginning of the gastrointestinal tract) side A and a distal side B.
- The distal side B is pulled up to be connected with whichever organ it is destined to drain. For example, a portion of the stomach or small intestine is drained in bariatric surgery.
- Side B, which is pulled up to drain another organ, is referred to as the “roux limb.” Finally, the proximal side A is reconnected at a new location labeled C in our diagram called the jejuno-jejunostomy (JJ Anastomosis) or small bowel connection.
- The small bowel connection creates what diagrammatically resembles the letter “Y.” The pulled-up portion of the small intestine called the roux limb makes one arm of the letter “Y,” which ends at the small bowel connection. The near side, referred to as the Biliopancreatic limb, or BP limb makes the other arm of the letter “Y” and ends at the small bowel connection. The base of the letter “Y” is the remainder of the small intestine, now referred to as the common channel.
How does a Roux-en-Y work in Bariatric Surgery?
Swallowed food travels down the esophagus into a portion of the stomach and or the first portion of the small intestine depending upon the bariatric procedure performed. The food then enters the roux limb, which has significantly less nutrient absorption because no digestive juices aid the absorption of nutrients.
The digestive juices flow down the other arm of the “Y,” called the BP or Biliopancreatic limb. These digestive juices originate from any remaining stomach, the liver, and the pancreas. Beyond the small bowel connection, the food mixes with digestive juices in the remaining small intestine, called the common channel, where absorption of nutrients now occurs. So normal absorption is absent in the BP limb bc food doesn’t enter that portion and also decreased in the roux limb due to no digestive juices. As a result, the roux-en-y creates malabsorption of ingested nutrients.
Since absorption of nutrients occurs near normally in the common channel, different procedures have different lengths to their common channel. For example, in a gastric bypass, the common channel is not typically measured but is very long and varies from person to person due to inter-person variability in overall bowel length. On the other hand, in the duodenal switch, the common channel is reasonably short, somewhere between 3 to 9 feet in length (100cm to 300cm).
The portion of the gastrointestinal tract that food travels through is called the Alimentary Tract, which is the roux limb length plus the common channel length. In the gastric bypass, the alimentary tract is a short roux limb with a long common channel. Likewise, the duodenal switch is a short roux limb and a short common channel.
Interestingly, the small intestine can change its ability to absorb nutrients. After creating a short common channel, the body recognizes its inability to absorb as many nutrients as before the roux-en-y and works to correct this change. As a result, over the next year or so, the common channel begins to absorb more nutrients than it previously had to make up for the difference.
We know weight loss effects are not solely due to decreased nutrient absorption. Instead, the alteration in the flow of food through the gastrointestinal tract changes hormones the gastrointestinal tract produces, which alter how our brain sets our bodies’ weight.
Which Bariatric Procedures Use a Roux-en-Y Small Intestinal Connection?
- Roux -en-y Gastric Bypass
- Duodenal Switch
What is a Loop Small Intestinal Connection?
Around 1880 Polish surgeon Ludwik Rydygier and German surgeon Theodore Billroth used a loop of the small intestine to reconstruct gastrointestinal tract anatomy after the removal of stomach cancer. This technique is still used for certain cancers, ulcer diseases, and bariatric surgeries.
Steps to Creating a Loop Small Intestinal Connection
2.
- Step one shows normal anatomy before any procedure has been performed. The gastrointestinal tract is reminiscent of a garden hose with a beginning or proximal portion and an end or distal portion. The small intestine measures, on average, about 22 feet long (7 meters).
- At any location along the small intestine, you can pull a loop of the intestine up to connect to another portion of the gastrointestinal tract. For example, the duodenum or stomach, as shown by the red arrows.
- The small intestine before the loop connection is called the Afferent limb, and the small intestine after the loop connection is called the Efferent limb.
How does a Loop Small Intestinal Connection work in Bariatric Surgery?
Swallowed food travels down the esophagus into a portion of the stomach and or the first portion of the small intestine, depending upon the bariatric procedure performed. The food then enters the Efferent limb. The digestive juices from the remaining stomach, liver, and pancreas flow down the efferent limb and join the food in the efferent limb allowing for near-normal absorption of nutrients.
Since absorption of nutrients occurs near normally in the efferent limb, different procedures have different lengths of their efferent limb. In a One Anastomosis Gastric Bypass, the efferent limb is not typically measured but is very long and varies from person to person due to inter-person variability in overall bowel length. In the Single Anastomosis Duodenal Ileal Bypass With Sleeve, the efferent limb is constructed to be reasonably short, around 9 feet in length (300cm).
The portion of the gastrointestinal tract that food travels through is called the Alimentary Tract. With a loop configuration, food doesn’t travel through the afferent limb. In the One Anastomosis Gastric Bypass, the alimentary tract is a short afferent limb with a long efferent limb. In the Single Anastomosis Duodenal Ileal Bypass With Sleeve, it is a long afferent limb and a short efferent limb.
Interestingly, the small intestine can change its ability to absorb nutrients. After creation of a short efferent limb, the body recognizes its inability to absorb as many nutrients compared to before the procedure and works to correct this change. As a result, over the next year or so, the alimentary tract begins to absorb more nutrients than it previously had to make up for the difference.
We know weight loss effects are not solely due to decreased nutrient absorption. The alteration in the flow of food through the gastrointestinal tract changes hormones the gastrointestinal tract produces, which alter how our brain sets our bodies weight.
Which Bariatric Procedures Use a Loop Small Intestinal Connection?
- One Anastomosis Gastric Bypass
- Single Anastomosis Duodenal Ileal Bypass With Sleeve