What is weight loss surgery?
Weight loss surgery, sometimes called "bariatric surgery," is surgery to help you lose weight. Bariatric surgical procedures affect weight loss through two fundamental mechanisms: (1) malabsorption works by changing the path food takes through your gut so that you take in fewer calories and nutrients and (2) restriction works by making your stomach smaller. Some procedures have both a restrictive and malabsorptive component. There is also growing recognition that bariatric surgical procedures contribute to neurohormonal effects on the regulation of energy balance.
Prevalence: -- Bariatric surgery is one of the fastest growing operative procedures performed worldwide, with an estimated >340,000 operations performed in 2011.
Who can have weight loss surgery? — Doctors use a measure called "body mass index," or BMI, to decide who can have weight loss surgery. Your BMI* will tell you whether your weight is Suitable for your height.
Weight loss surgery is appropriate only if you have not been able to lose weight through other means and if you:
Have a BMI above 40 and have not responded to diet, exercise, or weight loss medicines; or
Have a BMI above 35 and also have a medical problem related to obesity, such as diabetes, heart disease, or high blood pressure; or
Have a BMI above 30, but only if you have certain medical conditions.
*NOTE: BMI is calculated by dividing your Weight (in Kilograms) by your Height (in centimeters) Squared i.e: (Weight)/(Height)^2.
Are there different types of weight loss surgery?
Yes. There are many different types. The 3 most common are:
●Gastric banding - (gastric is another word for "stomach") – Adjustable gastric banding (AGB) is a purely restrictive procedure that compartmentalizes the upper stomach by placing a tight, adjustable prosthetic band around the entrance to the stomach, making a small pouch. The doctor can add or remove fluid through a button under your skin that is connected to the band with tubing. That way, the doctor can adjust how tight the band is. The tighter the band wraps around the stomach, the slower food passes from the pouch to the rest of the stomach.
The gastric band consists of a soft, locking silicone ring connected to an infusion port placed in the subcutaneous tissue. The port may be accessed with relative ease by a syringe and needle. Injection of saline into the port leads to a reduction in the band diameter, resulting in an increased degree of restriction. The band is adjustable and is placed laparoscopically. The goal of band adjustments is to give the patient a restriction of about a cup of dried food, and satiety for at least 1.5 to 2 hrs after a meal.
Expected weight loss LAGB — LAGB results in an approximate 50 to 60 percent excess weight loss at two years. Many patients have been able to sustain durable weight loss and comorbidity resolution with proper use and maintenance of the band.
Gastric bypass is short for "Roux-en-Y gastric bypass," and is sometimes called "RYGB." The RYGB is characterized by a small (less than 30 mL) proximal gastric pouch that is divided and separated from the distal stomach and anastomosed to a Roux limb of small bowel 75 to 150 cm in length. The small gastric pouch and the narrow anastomotic outlet serve to restrict caloric intake, while the significant digestion and absorption of nutrients occur in the common channel where gastric acid, pepsin, intrinsic factor, pancreatic enzymes, and bile mix with ingested food.
The Roux limb (or alimentary limb) is anastomosed to the new gastric pouch, and functions to drain consumed food. Primary digestion and absorption of nutrients then occur in the resultant common channel where pancreatic enzymes and bile mix with ingested food.]
Weight loss mechanism RYGB — While the RYGB, with its small pouch, is primarily a restrictive operation, a malabsorptive component also contributes to weight loss. Other mechanisms, such as Roux limb length, and gut hormones, may have a role in the weight loss seen following gastric bypass:
●The optimal length of the Roux limb in achieving the best balance between weight reduction and complications of malabsorption is controversial.
Expected weight loss RYGB — The expected excess weight loss after two years is approximately 70 percent.
Gastric sleeve :
Gastric sleeve, also known as "sleeve gastrectomy," is a partial gastrectomy, in which the majority of the greater curvature of the stomach is removed and a tubular stomach is created. The sleeve gastrectomy is technically easier to perform and viewed as “not as drastic” by patients. In 2011, it was the second most commonly performed bariatric procedure worldwide; approximately 28 percent of all procedures.
It is technically easier to perform than the RYGB, as it does not require multiple anastomoses. It is also safer, as it reduces the risks of protein and mineral malabsorption. The tubular stomach is small in its capacity (restriction), resistant to stretching due to the absence of the fundus, and has few ghrelin-producing cells (a gut hormone involved in regulating food intake). Although sleeve gastrectomy is a restrictive procedure, gastric motility changes also occur with surgery and may affect weight loss o Expected weight loss sleeve gastrectomy — At two years, the expected excess weight loss is approximately 60 percent.
The mini-gastric bypass (MGB), a modification of the loop gastric bypass and technically easier to perform than a Roux-en-Y gastric bypass (RYGB), is performed laparoscopically. MGB is a safe and straightforward procedure, can be quickly revised, converted, or reversed, and has increasing worldwide acceptance.
The MGB includes the division of the stomach between the antrum and body on the lesser curvature. The stomach is further divided in the cephalad direction to the angle of His. This subsequent pouch is anastomosed to the jejunum.
Weight loss mechanism MGB — The MGB combines restrictive as well as malabsorptive properties for weight loss. There are likely hormonal changes that occur such that insulin sensitivity improves and hunger is abated. limited data documenting effective long-term outcomes.
Expected excess weight loss — In one study, 95 percent of patients achieved 50 percent excess weight loss at 18 months; the maximal excess weight loss was 72 percent. In another study, patients achieved, on average, 71.5 percent excess weight loss (range 45 to 98 percent) after five years, one randomized control trial did indicate that the MGB has superior diabetes control than the sleeve gastrectomy (SG)
The intragastric balloon (IGB) consists of a soft, saline-filled balloon that promotes a feeling of satiety and restriction. An IGB has been advocated for use as a bridge to a more definitive surgical procedure. It used to treat obesity in adults with a body mass index of 30 to 40 kg/m2, with one or more comorbid conditions such as diabetes, hypertension, or hypercholesterolemia. It is intended for patients who have failed previous attempts at weight loss through diet and exercise alone.
IGB is inserted endoscopically and filled with 400 to 700 mL of saline, generally for a maximum of six months, beyond which time the leak rate increases significantly. A deflated balloon can migrate into the small intestine and cause bowel obstruction. Removal requires a second endoscopic procedure.
The IGB is purely a restrictive procedure. Weight loss is dependent on adherence to lifestyle changes and patient compliance.
Expected weight loss IGB as much as 33 percent excess weight loss has been reported, however, only 23 percent of patients maintained more than 20 percent of their excess weight loss.
* How is the surgery done?
All the different types of weight loss surgery can be done as "open" surgery or as "laparoscopic" surgery. For open surgery, the surgeon cuts open the belly and work on the organs directly. For laparoscopic surgery, the surgeon inserts a narrow tool that has a tiny camera on the end into the belly. This tool is called a "laparoscope” or “keyhole" surgery. It allows the surgeon to see inside the belly without opening it up all the way. Then the surgeon can do the surgery using other tools that fit through small openings in the belly and that can be controlled from the outside.
How do the different types of surgery compare?
Each type of weight loss surgery is different, and each has different benefits and downsides.
Gastric banding is probably the simplest form of weight loss surgery. It involves the least amount of cutting and it can be adjusted or even undone. Gastric banding also leads to the least amount of overall weight loss. Plus, people who have gastric banding need to see the doctor often for adjustments, and some end up needing the band taken out.
Gastric bypass leads to the most weight loss and works the fastest, but it involves the most serious surgery with the highest risks. It can also cause problems in how your body absorbs nutrients. As a result it can lead to "nutritional deficiencies," meaning that your body is missing essential nutrients. This can sometimes make you sick. If you have gastric bypass, your doctor will monitor your nutrient levels afterward.
Sleeve gastrectomy is safer than gastric bypass because it does not involve rerouting or cutting and reattaching the intestines, and because it is less likely to cause problems with how you absorb nutrients. It might also be safer than the gastric banding because it does not involve any plastic materials that stay in your body.
How do I know which surgery is best for me?
The decision about which type of surgery to have is essential. Discuss your choices with your doctor.
If you have different options, ask the following questions:
About how much weight can I expect to lose with each option?
How long will it take me to lose the weight?
What are the risks of each option for someone like me?
What changes will I need to make to my diet and lifestyle with each option?
Whatever you decide, make sure your surgeon is very experienced with weight loss surgery. Also, check with the staff at your treatment center." If you are at all unsure about your decision, you can ask for an opinion from another doctor.
What are the benefits of surgery?
In addition to helping you lose weight, surgery can help improve or even get rid of certain health problems, including:
●High blood pressure
●Sleep apnea, a disorder that causes you to stop breathing for short amounts of time while you sleep
●Gastro-oesophageal reflux disease, a condition that causes heartburn
What are the risks of surgery?
The risks of surgery are different depending on:
●What type of weight loss surgery you have
●Whether your surgery is open or laparoscopic
●Your age and overall health
●How experienced your surgeon
In general, the risks could include:
●Infection inside the belly or in the wounds from surgery
●Leaks from the incisions on the stomach or intestine
●A blockage or tear in the intestines
●Problems with the heart or lungs
●The need for more surgery
Will I need to change the way I eat after surgery?
Yes. Work with a nutritionist (a food expert) to learn how your diet should change.
You will need to eat healthy foods that "work with" your surgery. For example, you should choose foods high in protein and low in fat and calories. You should also avoid liquid foods that are high in calories, such as ice cream. If you eat the wrong things, you could hurt your chances of losing weight.
If you have gastric bypass, you will need to avoid certain foods that could make you sick. Plus you will probably need to take special multivitamins with minerals. That's because gastric bypass surgery can make it hard for your body to get all the nutrition it needs. You must keep taking the vitamins for the rest of your life. Your body will always need them to stay healthy.