Roux-en-Y Gastric Bypass

The Roux-en-Y gastric bypass (RYGB) has been around in one form or another since the 1960s. Globally it is the most common weight loss procedure being especially popular in the US where it was first developed. The name comes from a Swiss surgeon: Dr Cesar Roux who developed the techniques of joining up the bowel which is used in this operation.

We have the most long-term data about the RYGB and as such it has become the operation against which all other obesity operations are compared. However, although it is a standard to compare against it is not a ‘gold’ standard since all bariatric operations have their good and bad aspects and the RYGB has specific drawbacks too. One of the major advances has been the move to perform this surgery laparoscopically, which has reduced post-operative discomfort and length of hospital stay with a shorter time to return to normal activities but with preserved safety. This can be written as LRYGB but since I almost never do this as an open procedure, I just write RYGB.

RYGB has at least three effects on patients relationship with food and thereby their weight. To begin with, they are restrictive with portions sizes reduced by their new, smaller sized gastric (stomach) pouch that is formed by the surgery. This is done using a special surgical stapler – this seals (with many tiny titanium staples) and cuts at the same time. Eating more than this pouch can hold will lead to discomfort and vomiting so patients eat less and feel full quickly. 

The second effect is of malabsorption: not all the calories you eat are absorbed by the body. This is because of the bypass element. The pouch is re-attached to the small bowel further down (around 1.5m in fact) than where the food usually would have been. At this further point, the food then mixes with re-directed gastric and pancreatic juices so that digestion can begin. Hunger is significantly reduced due to complex hormonal feedback changes (mostly be a reduction in the hunger hormone – Ghrelin). As a result, patients don’t have as much hunger, feel full quickly when eating so don’t eat as much and don’t absorb all the calories that they eat. This is great for weight loss but some nutrients are also not absorbed as well. So patients need to take extra (supplemental) vitamins and minerals every day and have regular blood tests to check that their vitamin and mineral levels are healthy. Deficiencies are possible and can be dangerous if they do not take the supplements. 

Weight loss is most rapid in the first three months after surgery but it can take 18 months after a RYGB for weight loss to plateau. Every person is different and it depends on the commitment and lifestyle changes that patients make but on average, patients loss around 30% of their total body weight or around 60-70% of their excess weight with a RYGB over 18 months. But everyone is different, some lose weight faster, some slower, some lose more than this and some less. There is no way to predict exactly how much weight that patients will lose but it is uncommon not to lose some weight. This weight loss and other hormonal effects mean that there can also be dramatic improvements in medical conditions such as diabetes and hypertension. Many patients go into complete ‘remission’ from their type II diabetes - meaning that they no longer require medication such as insulin or oral tablets to help them control their sugars. Hypertension and high cholesterol can also resolve and sleep apnoea also often improves. 

It is important to make permanent changes in lifestyle in the first couple of years after surgery while the operation is working best. As over time, the operation’s effects do fade – the restriction can dissipate as the gastric pouch stretches over time and body can adapt or compensates for the malabsorptive effect. 

· Small meals & less hunger

· Feel fuller quicker and stay fuller for longer

· Lose 30% of total body weight – viewed as the ‘standard’ that we measure all weight loss operations against

· Significant effects on co-morbidities: resolution of type 2 diabetes, improvement in hypertension, reduce sleep apnoea etc.

· An end-point operation if other surgeries fail or lead to a complication

· Reversible (although a major operation to do so)

· Technically difficult procedure with two joins of the bowel, means that risk of complications is relatively high

· Not technically possible in high BMI patients (BMI>55kg/m2)

· Complications possible such as leaks and bleeds – see following section

· Specific complication of internal hernia in 5% of patients where bowel can twist causing pain or blockage or can damage bowel and threaten life

· No access to the duodenum with a gastroscope due to the bypassed bowel

· Daily vitamin/mineral supplements for life

· Annual blood tests required

· Dumping syndrome when eating high carbohydrate meals

· Ulcers can form at the join between the pouch and the bowel