In the Roux-en-Y Gastric Bypass, the size of the stomach is reduced to make a small stomach pouch using titanium staples, this reduces the amount that can be eaten before feeling full. Unlike the traditional stomach stapling where the food then passes through the full length of the intestine where all the calories are absorbed, the food only passes along part of the small intestine with much of the stomach and the upper part of the small intestine being bypassed. This means that all of the calories do not get absorbed. There is a third effect of the RNY gastric bypass which is called “Dumping”. When dumping occurs you feel light headed and nauseated and may develop diarrhoea. This happens in response to over-eating sweet foods or easily digestible non sweet carbohydrates that move through the intestine too quickly. Many patients never experience dumping, but in those who do, they lose the sweet taste and craving, particularly for chocolate. This can be very valuable in helping to change old bad habits.
It is this triple effect of reducing the amount of food you can eat, then reducing the calories that you can absorb from it, combined with dumping as a protection against over-indulgence with the wrong kind of food which makes the operation so effective.
Weight loss after the operation is initially very swift – most patients will lose a stone (14 lbs) a month. This will slow down with time as you approach your target weight – otherwise there would be a risk of overshooting.
Patients are individual people and no two are the same. Of course different patients need to lose different amounts of weight and the dimensions of the bypass are adjusted to take this into account. As a rule of thumb however, patients will lose on average about 40% of their starting weight in the first year and about half of the patients can halve their weight after 18 months. After about 18 months the weight will probably have levelled off and most people are happy with their weight at this stage. It is still possible to lose more weight by a combination of regular exercise and additional dieting usually by reducing high calorie snack foods or fluids rather than reducing the meal size. Unlike ordinary dieting, where weight is regained rapidly when the diet stops, weight loss after this surgery is more permanent. Once lost, weight tends to stay off.
The gastric bypass operation has an excellent long term track record with good follow up data on several thousand patients who have been observed for up to twenty years. Weight loss is shown to be durable but to achieve good results is a two way thing in that following the rules in the long term is important. Generally once patients settle into their new lifestyle, their new pattern of eating becomes their new way of life and breaking the rules long term is extremely uncommon. It is recommended that post-op patients have their doctor check their blood count at least once a year to make sure that they are not anaemic or nutritionally defficient. Provided they are taking their supplements and eating a blanced diet this is generally not a problem.
Most of this information was taken from “Guidelines for Patients Undergoing the Gastric Bypass Procedure” booklet which was given to me by Mr Stephen Pollard (my surgeon) at my initial consultation.
Mr. Pollard trained at London and Cambridge, and also in the USA. In 1994, he and his surgical team went to Richmond, Virginia to learn the surgical technique of the RNY Gastric bypass procedure and to familiarise themselves with the special needs of this group of patients – including their assessment and aftercare as well as the operation itself. He operates exclusively on patients with disorders of the gastrointestinal tract. As well as running the most active obesity surgery program in the UK, he is also Director of Liver and Intestinal Transplantation in Leeds, and runs one of the largest and most successful intestinal transplant units in Europe.
Mr Pollard sees everyone who is referred to him for this procedure personally, and discusses with them whether or not the operation is suitable in their individual case. He is personally present at all the gastric bypass operations that are carried out, and reviews patients progress in the clinic after the operation. Although often accompanied by other members of the team, the review of patients post-operatively is not delegated to trainees.
Learning and practicing the RNY procedure was embarked upon by Mr Pollard because of poor functional results and unsatisfactory weight loss which was observed in a proportion of patients under going the more traditional Vertical Banded Gastroplasty. The RNY complication rate is under 10% and mortality under 0.3%. The average BMI at the time of surgery is 51 kg/m2.