Laparoscopic Gastric Bypass

The laparoscopic Roux-en-Y (pronounced “rue on why”) gastric bypass is now an established operation for the treatment of morbid obesity.

At present this procedure is performed in patients where the banding may not be suitable because of eating habits. Some data also supports the use of this surgery for patients who are heavier (higher body mass index) although the band can also have excellent outcomes in this patient group. The gastric bypass is an effective procedure for patients who have diabetes. The procedure often leads to patients with Type 2 diabetes reducing their diabetic medication or stopping it all together.

The operation

This is performed by laparoscopy. This means that the abdomen is not actually opened but instead the procedure is performed by instruments passed through about five 1cm or so incisions.

The stomach is stapled off to produce a very small pouch in the upper stomach. A loop of small bowel is then joined onto this small pouch. This leads to a reduction of absorption of fats and proteins. This is because of a bypass of a length of small intestine and of the enzymes required for digestion.

An egg cup sized (less than 1 ounce) stomach pouch is created and restricts how much a patient is able to eat. The patient feels full after eating only a few bites of food. Limiting the amount of calories and nutrients that are absorbed: The stomach and first portion of small bowel are bypassed, which limits absorption. Hormonal changes: Production of ghrelin, a hormone that increases appetite, is reduced after gastric bypass surgery and most patients are not as hungry as they were before surgery. Patients with type 2 diabetes mellitus also improve their blood sugars soon after surgery, before any weight loss has occurred. This is also due to hormonal changes.

Patients are allowed to drink liquids after 36 hours and are on liquids for 2 weeks and on a soft diet for 2 weeks. Solid food is slowly introduced after 4 weeks. The in patient stay ranges from 3-5 days.

Outcomes

Follow up is essential to detect protein malnutrition and vitamin, calcium and iron deficiencies and supplements need to be taken routinely and regularly.

The published literature reports an expected 60 -70% of excess weight loss at 2 years after the procedure. The Gastric Bypass operation helps achieve weight loss by three mechanisms: a restrictive effect, a reduction in absorption, and probably some effect on appetite.

Advantages of Gastric Bypass surgery:

• The surgery is an excellent tool for gaining long-term control of weight. Patients, on average, have an excess body weight loss of 60% to 70% at one year, and an average of 50% to 60%.
• Improvement of most obesity-related health problems is achievable for most patients. Long-term weight loss requires dietary compliance, exercise, and behavioural changes

Disadvantages of Gastric Bypass surgery:

• Due to bypassing of a portion of bowel (duodenum), some vitamin and mineral deficiencies can occur. Iron and calcium are normally absorbed in the duodenum; after surgery, patients need to take iron and calcium supplements, as well as multivitamins and vitamin B-12.
• The bypassed portion of the stomach, duodenum, and segments of the small intestine cannot be easily visualized using X-ray or endoscopy if problems such as ulcers, bleeding, or cancer should occur. Rarely, surgery may be needed to assess this part of the gastrointestinal (GI) tract.
• This surgery is meant to be permanent, although reversal would be possible in very rare instances if medically necessary. Reversal would be a major procedure, and patients would probably gain all of their weight back, along with the associated co-morbidities