There are several different types of weight loss surgery and it is important to understand the differences among them. In order to qualify for weight loss surgery, you must have a Body Mass Index (BMI) of 40 or higher or a BMI of 35 or higher with at least one co-morbidity. Common comorbidities include diabetes, sleep apnea, high blood pressure, joint problems and incontinence. Anyone who qualifies for weight loss surgery qualifies for any of the weight loss surgery options listed below. Here is an overview of the three primary types of weight loss surgery available today:
- Lap Band. In lap band surgery, a laparoscopic donut-shaped rigid silicone band is put around your stomach and connected to a port just under the skin in the wall of the stomach. (A tube comes off of the band and leads to the port.) Doctors inject saline into the port to adjust the lap band, making it tighter or looser.
Lap band surgery is purely restrictive: It basically creates a small pouch at the top part of your stomach, which affects both how much food will fit into your stomach and through your stoma (or the opening at the bottom of the pouch). Of the major weight loss surgeries available, lap band is the least invasive of the surgeries, requires the shortest time under anesthesia and enables people to return to work within a couple of days. However, keep in mind the following consequences of lap band surgery:
- Immediately after surgery, patients are allowed only clear liquids, and the progression to solids is slow. (You start out with only eight teaspoons of food!)
- People with lap bands must eat slowly, chew their food thoroughly and stop when they feel full; only three small portions three times per day are allowed.
- People with lap bands must have regular check-ups and follow-up care to ensure that the band is adjusted properly.
- Some people have trouble getting their bands adjusted correctly - too loose and they don't lose weight, too tight and they throw up frequently.
Lap band recipients average a loss of 60% of their excess weight. Lap band surgery is easy to sabotage if you drink a lot of high-calorie liquids such as milkshakes, which can cause regain.
- Roux-En-Y Gastric Bypass. This surgery is named after the intestinal limb created by the sugery, which is known as the Roux-En-Y intestinal limb. In this gastric bypass surgery, surgeons create a tiny pouch at the top of your stomach (usually by stapling it off) and leave the rest of the stomach in your body. Your pouch (your new stomach) is very small, traditionally only ½ to one ounce. Food no longer travels to the bottom part of the stomach that has been stapled off but that part of the stomach continues to produce stomach acids. The small intestine is connected directly to the reduced stomach, with a small hole between the two known as a stoma. Because food bypasses the lower stomach, the first segment of the small intestine (the duodenum), and the first portion of the the second segment of the small intestine (the jejunum), the amount of calories and nutrients the body absorbs is greatly reduced (this is called malabsorption).
Because food passes from the stomach directly into the intestine minus the usual regulating influence of the pyloric valve, there are several possible complications involving the stoma.
- If a large chunk of food becomes trapped in the stoma instead of passing through into the small intestine, you can end up vomiting until it comes out or having to have it removed by a doctor.
- Food, especially sugar, sometimes passes directly from the stomach into the small intestine too quickly, a process known as "dumping." The results of dumping syndrome can be severe, including experiencing lightheadedness and the shakes, sweating, nausea, weakness, fainting, and diarrhea shortly after eating. Approximately 60% of gastric bypass patients experience dumping syndrome to some degree.
In addition to the possible complications involving the stoma, there are other consequences to consider:
- Between 5-15% of the time, the connection between the stomach and the intestine narrows, causing nausea and vomiting after eating.
- Immediately after surgery, you will be on a clear liquid diet. You will then advance to a diet of pureed foods. One month after surgery, you will be allowed to advance to more regular foods, though some people return to pureed foods because they are more easily tolerated.
- You can not eat large portions of food at one time (an average portion is approximately 1/2 cup).
- An iron and vitamin B12 deficiency occurs more than 30% of the time, and about half of those people with an iron deficiency develop anemia.
- Ulcers, hernias, and an enlargement of the bypassed stomach are additional possible complications.
- You are also no longer able to take non-steroidal anti-inflammatory drugs (NSAIDS).
Approximately 30% of gastric bypass patients experience a significant weight regain but successful gastric bypass patients lose 60-75% of their excess weight.
- Duodenal Switch is named after the duodenum, which is the first segment of the small intestine. Duodenal switch is a relative newcomer to the weight loss surgery options, having been around since the late eighties. Duodenum is a more invasive surgery and is a difficult surgery to learn and to perform, yet duodenal switch surgery does seem to address many of the long-term issues presented by other weight loss surgery options.
In duodenal switch surgery, the entire small intestine is measured, then divided in a 60/40 ratio. The lower portion of the intestine is the forty percent and it is brought up and connected just below the pyloric valve of the stomach, creating the enteric limb through which food passes. The sixty percent remaining stays connected to the liver and pancreas so that bile and pancreatic fluids continue to flow through that part of the intestine, which then connects to the enteric limb at approximately 100 cm from the large intestine. Since bile and pancreatic fluid are required in order to digest fats, you digest fats for only the last 100 cm of your intestine, or approximately 18 percent of the fat that you would normally digest. Proteins and carbohydrates are also absorbed at a 60 percent ratio, but sugar is absorbed at 100 percent. Thus someone undergoing this type of surgery needs to be willing to reduce their sugar intake significantly.
Along with the intestinal surgery, a partial vertical sleeve gastrectomy is performed on the stomach, in which the outer curvature of stomach is removed (reducing the overall stomach by approximately 75-90 percent). The remaining stomach still functions normally and is usually anywhere from 3-6 ounces. Because vertical sleeve gastrectomy still allows the stomach to function normally, patients can still take NSAIDS. Typically, the gall bladder and appendix are also removed. A common misconception is that intestine is removed in this surgery but this is not the case-no intestine is removed in duodenal switch surgery.
Possible complications from duodenal switch surgery include the possibility of malnutrition due to malabsorption of nutrients. In order to avoid this, you must take a multivitamin every day and 1500-2000 mg of calcium daily. You must also follow up regularly with your surgeon and have regular blood work to ensure that you have no vitamin deficiencies. Because you only absorb 60% of the protein you consume, you need to eat at least 60-80 grams of protein per day.
A recent ten-year study of duodenal switch surgery patients showed a loss of 80% of excess weight maintained over a ten-year period.
Risks common to all weight loss surgeries include the risk of being under anesthesia (which is higher for those who are obese). Keep in mind the day to day quality of your life as you decide on the weight loss surgery that is appropriate for you.