I'm going to cheat and copy paste here!
Taken from
Gastric bypass surgery - the mini gastric bypass by Healthier Weight UK which also has pics.
As with the standard Roux-en-Y gastric bypass (RYGBP) the mini gastric bypass (MGBP) works both by restricting the amount of food that can be eaten at any one time, and by altering gut hormones involved in appetite control. MGBP was first used in the late 1960s but abandoned in the 1970s. Today, because of developments in laparoscopic (“keyhole”) surgery, MGBP has started to come back into fashion and is being promoted as a quick and effective alternative to standard gastric bypass.
Mini Gastric Bypass - How is the operation performed?
How is the operation performed?
In the first part of mini gastric bypass surgery the stomach is divided and a small tube of stomach created which becomes the pouch. This is the restrictive part of the procedure and means that only a very small amount of food can be taken at any one time.
Next, the surgeon brings up a loop of bowel (about 200cm long) and joins this to the lower part of the stomach pouch. (The joining of bowel to bowel, or stomach to bowel is called an “anastamosis”). This means that food passes from the small pouch into the small bowel where it meets the digestive juices which have moved downwards from the main part of the stomach. In effect, therefore, about 2m of small bowel has been bypassed before absorption of food (and calories) can take place. Fewer calories absorbed, means weight loss.
The main difference between the standard Roux-en-Y gastric bypass procedure (RYGBP) and the mini gastric bypass (MGBP) can be seen by comparing the two diagrams opposite. It is clear that in the case of the MGBP there is only one anastamosis, whereas in the RYGBP there are two – an upper and a lower. Because of this the MGBP can be done in less time than the RYGBP and – at least theoretically – with fewer early complications.
Studies show that weight loss and health benefits resulting from mini gastric bypass are essentially the same as for standard Roux-en-Y gastric bypass.
Mini Gastric Bypass -The disadvantages
Are there are disadvantages to the MGBP?
There is one potentially serious problem with mini gastric bypass surgery. Because the pouch is small and is joined close to the flow of digestive juices, it is possible for these juices to “reflux” up into the stomach pouch causing erosion, inflammation and painful ulceration.
It must be said that most of the recent studies do not seem to report this as being much of a problem in practice, but if it occurs it can be difficult to deal with.
So is the MGBP preferable to the standard bypass?
At present, the short answer is probably not. Mini gastric bypass surgery is quicker because it is a single stage procedure, but in practice and in experienced hands the time difference is not great. There is some preliminary evidence to show that the early complication rate of MGBP is lower than that for RYGBP, but operative mortality is the same. Moreover short-term weight loss is virtually the same for both procedures - around 70% of excess weight. It is also worth bearing in mind that long-term data for MGBP are not yet available and the question of reflux – referred to earlier – has yet to be resolved.
