Speed and Amount of Weight Loss
The gastric bypass (RNY) and gastric sleeve (VSG) lead to faster weight loss. The expected weight loss with VSG is 50 to 70% of excess weight within two years; RNY leads to excess weight loss of about 80% within 18 months. Usually, heavier patients look towards the VSG and RNY, while the Adjustable Gastric Band (AGB) is sometimes used for lower BMI patients. Expected excess weight loss with AGB is 50% over two years.
The VSG can be the surgery of choice for heavier patients because the actual operation is a safer procedure than the RNY. However, the RNY could be better for you if you have diabetes since many patients have much better blood sugar control after the surgery.
Long Term Results
You may have a lower chance of keeping the weight off long-term with AGB compared to other surgeries, but that depends on several factors. You can keep the weight off if your band stays in place and if you make the commitment to continue to follow your WLS diet once you hit goal weight. The RNY has good long-term results for many patients who keep a good amount of weight off for 10 or more years. The VSG is a newer procedure and the jury is out on long-term results.
How It Works: Restriction, Malabsorption, and Hormones
All weight loss surgeries are “restrictive.” They restrict the amount of food you eat by making your stomach smaller so it fills up faster, with less food. The AGB does this by creating a small pouch that is separated from the larger portion of your stomach. The AGB is only restrictive, but it is the least invasive surgery type.
The RNY involves the surgeon separating the lower stomach, which is restrictive because it leaves you with only the upper stomach to hold food. The RNY is also malabsorptive because it leads to nutrient malabsorption. The surgeon connects the upper portion of your stomach to the lower part of your small intestine. After RNY, food “bypasses” the upper part of your small intestine which is where a good amount of digestion and absorption typically occur. That way, less of the food you eat is absorbed, so you get fewer calories. This is a benefit if you are looking for faster weight loss.
In the VSG, the surgeon removes about 75% of your stomach, leaving you with only a small tube-like “sleeve.” This is how it is restrictive. The VSG also helps you lose weight because it affects your hormones. Your stomach naturally produces a hormone called ghrelin that makes you hungry. When the surgeon takes out most of your stomach, you have less ghrelin and less hunger. The VSG may be for you if you always feel hungry.
Reversibility and Flexibility versus Implanted Devices
The AGB is an implanted device. That means you will have a foreign object in your body for good. Some patients do not mind this and prefer the AGB because it does not rearrange their insides.
Others prefer the RNY or VSG because there is no foreign object left inside your body. However, these options involve changes to your body. The RNY rearranges your digestive system, while the VSG removes most of your stomach.
Adjustability
The AGB is the only WLS option that is adjustable. You can tighten (or “fill”) the band to make it more restrictive and lose more weight, or loosen it to make it more comfortable. Loosening the band can also be helpful if you need to eat more food, such as if you become pregnant, or when you approach goal weight.
You are in the “green zone” when the band is tight enough for you to feel full between meals and lose weight, but not so tight that you feel side effects such as regurgitation, trouble eating solid foods, or coughing.
A drawback to the adjustability of the AGB is that you need to get it adjusted in a surgeon’s office. This can be inconvenient since you need to get it filled a few weeks after surgery, and may need to adjust it a few times before you get it right. It can also be difficult to find a surgeon who can do the adjustment for you.
You should always know the location of the nearest surgeon to fill or unfill your band if needed, whether pre-scheduled or in an emergency. This can be difficult if you get your band inserted far from home or even in another country.
There is a lot to consider when choosing a Weight Loss Surgery type, and we will look at even more factors in Part 2 of this series!