Surgery is reserved for individuals with a BMI of over forty. Surgery is considered if the BMI is 35 or more and the patient is afflicted with an at-risk condition, including sleep apnea, diabetes, heart disease, or a BMI of 30 with difficult to control diabetes or metabolic syndrome (Lim, 2021).
Bariatric procedures come in two different types: restrictive and malabsorptive. The restrictive type includes the vertical banded gastroplasty, sleeve gastrectomy, and the laparoscopic adjustable gastric band. The malabsorptive type includes the jejunoileal bypass, biliopancreatic diversion with duodenal switch, and biliopancreatic diversion. The Roux-en-Y gastric bypass (GYGB) is a combination of restrictive and malabsorptive (Lim, 2021 & American Society for Metabolic and Bariatric Surgery [ASMBS], 2021).
The vertical sleeve gastrectomy limits the amount of food taken into the body and reduces the amount of food used. This procedure uses staples and a band to create a long vertical tube or banana-shaped stomach. The procedure removes most of the stomach and reduces the hormone ghrelin, which lowers appetite. After two years, 60% weight loss is expected (Lim, 2021).
RYGB is the most commonly performed weight loss surgery in the US and is a combined restrictive and malabsorptive procedure. The restrictive part involves creating a small pouch to restrict food intake in the stomach. A section of the small intestine, Y-shaped, is attached to the pouch, so food bypasses the stomach, duodenum, and part of the jejunum to reduce the number of calories absorbed. After two years, weight loss is expected to be 70% (Lim, 2021).
The adjustable gastric band, which is not commonly done, is performed via laparoscope by placing a silicone rubber band around the upper end of the stomach. The banding makes a small pocket and a thin passage to the stomach. An access port is placed so the band can be made more loose or tight with an infusion of saline (ASMBS, 2021).
The biliopancreatic diversion with a duodenal switch is a complex procedure. Due to its high complication rate, it is not commonly performed. It removes a large part of the stomach, similar to vertical sleeve gastrectomy, to restrict the amount of food consumed. In addition, the small intestine is modified, leading to a limited ability of the duodenum to absorb food and vitamins. This procedure also modifies bile and other digestive juices, affecting digestion and the absorption of food. While this procedure may lead to significant weight loss, it can lead to many problems such as anemia, osteopenia, or osteoporosis (ASMBS, 2021).
The single anastomosis duodenal-ileal bypass with sleeve gastrectomy is a newer procedure. It is similar to the biliopancreatic diversion with a duodenal switch but takes less time to perform. The surgery starts with a sleeve gastrectomy, and then the intestine is shortened, and food goes through only the latter part of the small intestine. Digestive juices mix with the food to absorb vitamins and minerals. This surgery can be added to someone who already had a sleeve gastrectomy to enhance weight loss (ASMBS, 2021).
Research shows that weight loss ranged from 13% with adjustable gastric banding one year after surgery to 30.9% with RYGB. Those with gastric sleeves lost 23.4% of their baseline weight (Maciejewski et al., 2016).
Acute complications of these procedures include infection, bleeding, peritonitis, diarrhea, DVT, and PE. Long-term complications often include malabsorption of vitamins and minerals, leading to vitamin deficiencies, abdominal strictures, and hernias (Perreault, 2022).
Vitamins and minerals not absorbed well include vitamin B (vitamin B9 [folic acid] and B12 [cobalamin]), iron, copper, zinc, and calcium. If the surgery diverts the food from the biliary and pancreatic system, the fat-soluble vitamins (A, D, E, and K) are not absorbed well.
Hernias may include incisional hernias or internal hernias. An incisional hernia is a weakness that protrudes from the abdominal wall through a surgical incision. This hernia is less common when a laparoscope is used. An internal hernia occurs when the bowel is trapped in the lining of the abdomen.
Another problem is the dumping syndrome, which occurs after eating a meal high in carbohydrates and food moves too quickly into the small intestine resulting in abdominal pain, nausea, weakness, sweating, bloating, and dizziness (Perreault, 2022).
Weight loss is often accomplished quickly. While benefits may be great, anytime surgery is considered, it must be done carefully as it is associated with risks and complications. Long-term success after surgery is related to the patient's lifetime commitment to behavioral changes. Without continually working on the lifestyle changes, the patient will not get the full benefit from the surgery.
After bariatric surgery, the diet should be modified to prevent complications from the surgery. Careful adherence to the surgeon's recommendations is critical. Referral to a dietitian may also be indicated to assist in eating healthy and safely (especially in the first few months). Some recommendations include:
- After surgery, a clear liquid diet may be given for 1-2 weeks, followed by a complete liquid diet and then a pureed diet.
- Eat a low-calorie diet with balanced meals.
- Consume small portions.
- Initially, keep calories low (less than 600 calories a day), which will then be gradually increased.
- Eat slowly.
- Avoid foods that are not easily chewed: steak, pork, rice, raw vegetables, and fresh fruits.
- Chew all food thoroughly.
- Do not use straws and do not drink carbonated beverages as these may introduce air into the GI tract and cause discomfort.
- Drink water and non-caffeinated low-calorie beverages between meals.
- Minimize or avoid alcohol altogether as it is absorbed very quickly.
- Consume high protein foods – try to get at least 65 grams a day.
- Pills/vitamins that are taken may need to be cut into small pieces to allow them to be absorbed.
- Supplements are recommended after surgery, including (but not limited to):
- High potency multivitamin
- Calcium supplement (1,200 to 2,000 mg a day divided, preferably as calcium citrate)
- Vitamin D supplement (800 to 1,000 international units a day)
- Vitamin B12 (500 mcg day)