How the AGB Functions
Any sufficiently advanced technology is indistinguishable from magic.
-Arthur C. Clarke, The Lost Worlds of 2001
In the last chapter we looked at the various types of bariatric surgery and determined that while the adjustable gastric band (AGB) is weight-loss surgery, it doesn't really fall into the category of traditional bariatric surgery. The AGB is a tool, and the purpose of this chapter is to offer details about how it is placed and how it functions.
Overview of the AGB's Function
The basic idea behind the AGB is really quite simple. The band acts like a tourniquet around the upper part of the stomach, limiting the amount of food you can eat. It artificially separates the stomach into a small upper pouch and a much larger lower pouch. The lower pouch receives food only as fast as the band will allow. (Please see the figure on the following page.)
The upper pouch fills up quickly and empties slowly. Restriction of the intake of food is created without the risk of stapling, diverting, or rearranging the stomach or any part of the digestive tract. The fact that the band doesn't require rearrangement of the digestive system explains why the AGB is the safest surgical option currently available for the management of obesity.
Controlling the amount of food the stomach pouch can hold is only part of the way the AGB works to promote weight loss. Perhaps the most remarkable effect of the band is its ability to reduce hunger. Anyone who has ever been on a diet knows that hunger is the main reason for failure. It takes only a small amount of food to fill the space above the band completely, yet patients report that the feeling of fullness is the same as if they'd eaten a sizable meal. Food tends to stay in the upper pouch for several hours after a meal, creating a sense of satiety.
Further, patients who have a band often say that they are simply not hungry, even when they haven't eaten anything. The physiologic reasons for this seemingly miraculous effect are not completely understood. However, it seems likely that the presence of any food or fluid within the upper pouch stimulates nerve impulses or hormones to be released from the stomach that shut off the hunger center in the brain. As a result, some people enjoy the absence of hunger for prolonged periods of time.
Like an adjustable tourniquet around the stomach, the band limits food consumption.
The key to making the band work is creating just the right amount of restriction. When it is appropriately adjusted, the band promotes weight loss, but at the same time it will allow adequate amounts of food and water to pass through into the rest of the digestive tract. If the band is too loose, it will not offer enough restriction to be effective. If it is too tight, it will severely block the flow of food and fluids through the stomach, leading to malnutrition or even acute dehydration.
When the band is properly adjusted, the opening between the two parts of the stomach is fairly narrow, like an hourglass. To achieve the proper amount of restriction, the band is inflated by injecting saline solution into a small reservoir that is placed under the skin and attached to the band by a length of tubing. The band can also be loosened by removing some or all of the saline. While this sounds pretty easy, properly adjusting the band can be quite challenging, and an entire chapter of this book is dedicated to the process.
Surgical Placement of the AGB
The operation to place the AGB is almost always performed using a technique known as operative laparoscopy. Sometimes this type of surgery is referred to as minimally invasive because there is no large incision as is common in traditional surgery.
The advantages of laparoscopy include less pain, faster recovery, and fewer noticeable scars. It is particularly beneficial for obese patients, since they are known to have higher surgical risks. Patients are subjected to less trauma, so they require less pain medication. They are up walking around more quickly and can resume normal activities right away.
During laparoscopic surgery a small tube, called a cannula, is placed into the abdominal cavity through the skin and muscular wall. The cavity is then inflated with carbon dioxide gas, similar to blowing up a balloon. The pressure of the gas creates space for the surgeon to work between the internal organs and the wall of the abdomen.
A long, thin telescope, called a laparoscope, is attached to a high-intensity light source and a miniature video camera. The camera is connected to a highresolution video monitor so that when the laparoscope is inserted into the abdomen, it offers the surgeon an extraordinary view of the internal organs.
Additional cannulas are inserted through the abdominal wall as conduits for specialized instruments to be used by the surgeon to perform the operation. The surgeon and entire team are able to watch every move on video monitors.
To expose the area of the upper stomach requires the liver to be physically lifted off the stomach. The liver is often quite large and somewhat immobile in very obese patients. This can prove to be a major obstacle in working around the upper part of the stomach. In extreme cases a large "fatty liver" can make it nearly impossible to perform the procedure safely. To avoid this situation and make the procedure safer and easier, my patients are placed on a preoperative low-fat, lowcarbohydrate diet for three weeks. (I present the details of the diet in Chapter 8: What to Expect before Surgery on pages 99-100.) This pre-op diet can pay big dividends, because the liver usually shrinks dramatically in just a short time.
During the surgery, an initial dissection of the upper stomach area is performed prior to placing the band. An experienced surgeon can usually accomplish this in just a few minutes, but the process can take considerably longer depending on how much fat is present around the lower esophagus and upper stomach. As a rule, the dissection tends to be more difficult in men than it is in women. Obese men have more fat around the stomach and other areas inside the abdomen than do obese women, who tend to carry more of their fat under the skin. When the band is in the right spot, it will create an upper stomach pouch that holds only a couple of ounces of food.
To be effective, the AGB must be placed around the stomach in the proper location. If it is placed too high, the pouch will be too small to hold enough food to allow for adequate nutrition. It is actually possible to place the band around the esophagus, which can lead to problems, including difficulty swallowing, blockage of the swallowing tube, or even injury to the esophagus.
If the band is placed too low, the pouch will be too big to be effective for weight loss. This makes the band ineffective for helping the patient lose weight. Also, if the band is too low, heartburn is a common symptom.
There are two bands that are most popular, primarily because they were the first two to be offered to the public, but there are sure to be many variations as the band gains popularity. The most popular band is 10 centimeters in circumference and holds about 4 cubic centimeters of saline. Another popular band is 11 centimeters and holds 10 cubic centimeters of saline.
Most of the time the smaller-size band can be placed around the stomach and the surrounding fat without any difficulty. However, if too much fatty tissue is included inside the band, it can cause early obstruction, which means that the band is so tight not even fluids can pass through. This problem can be avoided by removing some of the fat before the band is placed. But removing fat may be quite difficult and runs the risk of injuring the stomach. A better choice is to use a larger band, one designed specifically to avoid the possibility of early obstruction.
Once the appropriate band is selected, the surgeon first inflates it with saline to ensure that it doesn't leak. It is then deflated and inserted into the ab domen through one of the cannulas. An instrument is passed behind the stomach to pull the band tubing around. Then the tubing is threaded through an opening in the end of the band and is gradually pulled through until a locking mechanism snaps the band closed around the stomach. During this step there is a slight risk of injury to the stomach or other organs in the area.
The surgical risk depends in large part on the amount of fat around the stomach and the laparoscopic experience of the surgeon. An injury to the back wall of the stomach can be difficult to detect because the surgeon can't really see back there. If a perforation occurs in that area it can have disastrous consequences, especially if it is not immediately recognized. The spillage of stomach contents into the abdomen will nearly always lead to a major, life-threatening infection. Fortunately this is uncommon with the AGB, in comparison with other procedures such as gastric bypass.
An unrecognized hiatal hernia can also increase the possibility of problems while placing the band. (If part of the stomach pushes up through the muscles of the diaphragm, that is called a hiatal hernia.) This situation is actually quite common and is frequently associated with heartburn. If a small hiatal hernia is found, it should be repaired before the band placement can continue. However, if the hernia is larger than an inch and a half, the band may not be an appropriate choice. This situation is associated with a higher incidence of problems after surgery, including displacement of the band and possible recurrence of the hernia. In patients with symptoms of heartburn or chest pain or regurgitation of food prior to surgery, it is a good idea to have some type of testing to rule out a large hiatal hernia before deciding on the band.
Putting a band around the stomach is a bit like placing a ring around a balloon filled with water. The stomach is a very flexible, saclike structure, and over time it can change shape dramatically. If the AGB is not secured in some way, it will likely slide up or down as the stomach shifts around. To secure the band where it needs to remain, the surgeon pulls a portion of the stomach wall up over the band and sutures it above the band. The idea is to trap the band within a tunnel created by the stomach wall. This holds the band in much the same way as a belt loop holds a belt. A small percentage of bands escape this tunnel and start to slip up, or more often down, on the stomach. That is called band slippage, and this subject will be covered in detail later in this book.
Once the band is secured into place, the end of the band tubing is brought out of the abdominal cavity through one of the cannula openings. The tubing is then tunneled under the skin and attached to a reservoir, called the "port." The port is made of hard plastic, with a titanium steel bottom. The front of the port is specially designed with a silicon rubber plug, which can be penetrated with a specialized needle passed through the skin. This allows saline solution to be injected to adjust the tightness of the band. The silicon plug reseals as the specially designed needle is removed.
Most often the port is placed on the upper left side of the abdomen, but it can be situated almost anywhere on the abdominal wall. It only has to be accessible with a needle placed through the skin. Once the port is in place, it is covered by a layer of fat. The thicker the fatty layer the more difficult the port is to feel through the skin. For this reason, some surgeons elect to put the port up on the breastbone, where the fatty layer is generally thinner. While this location makes the port easier to feel and access with a needle, the result can be a visible swelling and a bump between the breasts. This will become even more obvious as the patient loses weight. For this reason, most surgeons prefer to place the port on the side of the abdomen.
Once the port has been sutured to the muscle, each of the small skin incisions is closed with dissolvable sutures. Small dressings are used to cover each incision site prior to the patient's leaving the operating room. Although this marks the end of the operation, for the patient it is only the beginning: the patient now has a new tool to help in the fight against obesity.
The AGB from a Surgeon's Viewpoint
As a surgeon, I am accustomed to taking direct treatment actions to correct any number of problems. Many physicians are drawn to a career as a surgeon because ailments with surgical treatment as an option-such as appendicitis and hernia are "fixable."
The surgeon's job typically involves making the diagnosis, explaining the procedure to the patient, and performing the operation. For many acute illnesses or conditions, the surgeon acts like a healthcare "firefighter." Once the patient has recovered from surgery (that is, the fire is out), the surgeon's work is done.
The surgeon's job stands in sharp contrast to many chronic medical conditions, which require long-term management. Obesity is just such a long-term problem, even when it is treated with an operation. Our modern society is constantly being advised that a "quick-fix" exists for virtually everything from bad breath and wrinkled skin to heartburn and insomnia. We obviously want just such a solution for obesity. We witness numerous promises of rapid weight loss and find it difficult to believe differently.
When I first started treating obese patients with the AGB, it was natural for me to think of the band operation the same way I have other surgical procedures. While I certainly understood that there were other issues that would need to be addressed, I hoped the procedure alone would lead to successful weight loss. That was clearly a false assumption. As I watched patients struggle with making the lifestyle changes I recommended, it became obvious what they really needed was a program to back up the procedure.
Getting our patients to understand that the AGB is not a cure-all for their weight problems has been the greatest challenge my staff and I face. Many patients come to us with the preconceived notion that getting a band means that they will never have to worry about their weight again. This is simply not true. The AGB is a tool. The surgical procedure is merely the installation of that tool, not an automatic weight-loss operation.
Dan's Story
I'd always been fat. My top weight was 355. I was 340 in my before photo, and 323 when I got banded in 2003. Now, four years later, I don't think of the change in my body just in terms of weight loss, but in changes in my life. My pants used to be a size 56 and are now a size 38 or 40. My shirts were 3X or 4X, and are now XL. I shop in regular stores, and not just in the "fat guys" store. I can also fit in restaurant booths, exercise easily, and do a whole host of other activities (even though I just had my sixty-fourth birthday) that just weren't possible when I had another 140 pounds on my body.
I work for a university library as the network information coordinator, and I lead the SmartBandsters, a Yahoo group aimed at helping people who are banded. I've seen thousands of people post their questions and concerns. One of the things I find is so many people, no matter what kind of weight-loss surgery they have, think they'll be magically cured. That's not so. The best analogy I have for life with the band is peeling away layers of an onion. There's always another layer underneath, especially if someone has been eating for psychological reasons.
I'm a recovering alcoholic and so is my wife. We've both been married before. One of the pluses for me working a 12-step program is that I've already dealt with a lot of my issues. I've found, being banded, that compulsive eating is like drinking. Things that tend to put the average drinker on to alcohol are described by the acronym HALT-hungry, angry, lonely, or tired. I know to watch myself if I'm in one of those four states of mind. Food is always there. And food is harder to handle because it's socially okay to eat, while drinking and drugs are not as socially acceptable.
There's a saying in AA, one scotch is too many and 100 is not enough. It's the same for me with various foods. Frito Lay had a commercial that said, "Betcha can't eat just one." No kidding. I know I can't have just one potato chip or one M&M. But with alcohol or drugs, I can simply avoid them. I can't stop eating. I have to fight that devil three or more times a day. What makes it more complicated is I'm eating in the presence of other people who can deal with food in more of a "normal" way. They can have just one and be okay.
While the band restricts my eating, one of the things the band will not stop me from is "grazing." If I'm eating three or four small meals a day, that'll work. But if I'm at a buffet the whole day and I just keep nibbling for several hours, then I'm going to eat several days' worth of food. So I work to avoid situations in which I can graze all day.
I'd say there are biological issues with weight, too. For example, some of us have issues with our brain chemistry. Obesity is not caused by a single issue. It is so multifaceted that you've got to deal not only with the physical but also with the rest.
One thing people don't realize is that it's possible with the band to gain the weight back. I believe that's more common with the bypass than the band, because the band gives you more time to modify your behavior. And the band is adjustable, while the bypass isn't. If a person is counting to a considerable extent on the restriction that comes with the bypass, that could be a problem, because the odds are they're going to lose the restriction over time.
I think it's smart for people to be in a band support group beforehand. However, many surgeons who perform band surgery also do gastric bypass. In a situation like that, some practices try to put all the patients in the same support group. I think that's a mistake. Bypass people lose so quickly at first that it can be discouraging to someone with a band who is going to lose more slowly, at the rate of a pound or two a week. And there are also other issues unique to band people that might not get addressed or are passed over in a mixed group.
One of the issues unique to band people is what some call productive burping, or PB-ing. It's more like baby spit-up, since it's coming from above your band. You can call it anything you want, but I found I had this problem until I learned to chew well. The standard is to chew 20 times, while putting down the fork between bites. Many people are used to shoveling food into their mouths in a hurry, such as when they're driving or eating in front of the television. Before I was banded, I was watching a football game and at halftime I realized I'd eaten the entire big bag of chips. I thought the dog had gotten into the chips, but then I remembered we didn't have a dog anymore. I've found mindful eating works better. I think about what I'm eating and pay attention with each bite to see whether I'm full or not.
After I got a band, I also realized that I had never experienced physical hunger, because I was eating all the time. Further, I'd never learned to discern the difference between physical and emotional hunger. Or knowing hunger from thirst. I've found that some people eat when they're thirsty. Learning those differences is important to band people, and it takes time.
I have modified some of the band "rules" in my own life. For example, I drink water, right up until I start a meal. Then I put the water glass away and tell the waiter or waitress I don't need a refill. I figure the water will run right through the pouch and won't wash food through if it is taken in first. But I stop drinking as soon as I start eating.
I have other tricks I use. For example, when they bring the meal in a restaurant, I ask them to bring the carry-out box at the same time they bring the food. Before I start eating, I divide my meal into a smaller portion and put the rest into the carry-out box. When I wasn't banded, I never took a carry-out box home from a restaurant. My parents grew up in the Depression, and we were poor. So we were taught to clean our plate, and I didn't leave the table until I was done-even if it meant eating eggplant, which I hated. That type of training put me in a position to clean my plate. So now I just make sure I don't have too much to eat when I start.
What I also see a lot is that band people don't want to exercise. I think exercise is another important change you have to make. Even when I weighed 355, I lifted weights, but I didn't jog like I do now.
Band people would be smart to decide beforehand if they want to tell people they're banded or not, and who they want to tell. Once you tell, you can't un-tell. One of my sisters is head of medical records in a big hospital, and when I let her know I wanted to get a band, she reamed me. I told her, "You know me, I do research for a living. I've researched the band very carefully." Then I gave her some sources and suggested we talk again after she had checked it out. She called back in a few days and apologized.
I've only had three fills. I just haven't needed more. What I notice is that band people always want to talk about the size of the band and the amount of the fill. I think it's irrelevant, so I just don't talk about it. Fills are like Goldilocks and the Three Bears: it's either too big, too little, or just right. And the amount of the fill that works depends on the individual.
I've also had plastic surgery, a tummy tuck, to handle the excess skin around my middle because it was bothering me. I considered doing more, since I have excess skin on my arms, chest area, and inner thighs. But I asked my wife and she doesn't care. Since it doesn't bother me either, I decided not to have any more plastic surgery.
Changing behavior is the big thing. I see it a lot working with band patients online. There are always some who will keep spitting up every meal because they insist on doing things the way they've always done them. If they continue, they can dilate the pouch, erode the band, and all sorts of other things can happen. There are always a few who have their band taken out, almost always for behavioral reasons. And a few where the band and their stomach just don't get along. I've heard a lot of people who had reflux before the band don't have it anymore after they're banded, and others who never did have reflux experience it after they have a band. It seems there's never just one totally simple answer.
I don't see myself as a missionary for the band, but I am an educator. If I can help people by educating them, I'm happy to do so.
Is the Adjustable Gastric Band
Really Bariatric Surgery?
I am often asked if the AGB is bariatric surgery. As I pointed out in the previous chapter, all bariatric operations are classified as restrictive or malabsorptive, or in some cases, both. A restrictive procedure physically limits the amount of food you can eat, while a malabsorptive operation reduces the amount of food that can be absorbed in the process of digestion.
The adjustable gastric band is classified as a purely restrictive procedure. However, what makes it different from all other bariatric operations is the fact that the amount of restriction can be adjusted to meet the individual patient's needs. Most important, the adjustments can be made without the need for any additional surgery.
Adjusting the band ensures that every patient gets a custom fit. As a patient's circumstances change over time, the tightness of the AGB can be altered to meet those changing needs, such as pregnancy or other medical conditions. This is a truly unique feature, which makes the AGB the most versatile surgical option available for managing obesity.
Unlike typical bariatric operations, the AGB does not cause weight loss by itself. I commonly refer to the AGB as a pair of weight-loss "crutches." For someone with a broken leg, crutches can allow them to be mobile. However, the crutches don't walk by themselves. They are simply the tools the patient uses to accomplish the goal of ambulation. It is not enough that the individual wants to walk and buys crutches. They must also supply the energy to use the tool in order to walk.
Like the crutches, the AGB is a tool used by obese patients to gain control of their weight. The band provides guidance, encourages better eating habits, and strongly discourages overeating. It is a training tool designed to help the patient accomplish the weight-loss results they have been unable to achieve through willpower alone.
The results will depend in large part on how willing the patient is to change the behaviors that caused their obesity. If they are committed to making real changes in their eating habits and lifestyle, the band will provide the discipline. Through personal commitment, along with the support of a skilled team, remarkable results can be obtained.
But, as with any training process, the keys to success include both the motivation of the student and the quality of the instruction. Once properly installed and adjusted, the AGB can be used to help patients control how much food is taken in. In this sense, and in my opinion, the AGB is not like traditional bariatric surgical procedures. It is instead a very effective tool for a lifestyle change designed to interrupt the obesity cycle.
Breaking the Cycle of Failure
G. Dick Miller, Psychologist
There is a cycle of failure characterized by the punishment paradigm, which is this: "Pay attention only to negative behavior, and if positive behavior exhibits itself, ignore it." That type of thinking doesn't work. What works is instant feedback and positive reinforcement. In order for change to take place, it's necessary for the reinforcement to be stronger than the punishment. In other words, the brain must have a good emotional experience.
There's not much about eating right in the short-term that produces a good emotional experience for the brain. For example, if an overweight person eats well for a week, no one will say they're doing a great job. And it's entirely possible that after seven days of excellent food choices, the overweight person may not lose any weight. This amounts to the punishment paradigm, ignoring positive behavior.
But with the band, individuals know immediately they're eating less, and they feel satisfied, not hungry. Having a band is like the first two weeks of taking diet pills. It's easier to avoid abusing yourself with food when you're not driven by excessive hunger, when you feel satisfied. Of course, the body adjusts to diet pills after a short time, but the band doesn't have that limitation.
Further, the band is monitoring consistently, patiently, 24 hours a day, seven days a week. After a while, it's just easier to stop trying to get around it.
It's important to note that people who lost weight with the band didn't do so because the band changed their eating habits. The person changed. Patients can and sometimes do fight the band until they learn to change their thinking through positive reinforcement. What's great about the band is that it works despite rotten self-talk and self-depreciating language on the part of the patient. Whether anyone notices or not, many banded people are not hungry, know they ate less, know they feel better, and know they're transforming. No one is making them change; they're changing, and they know it. And that knowledge revolutionizes the way they feel about themselves.
I like the band because it's so clean-it provides consistent feedback and constant reinforcement. But, as in the use of any tool, patients must be honest so they get the correct fills and so nonworking thinking can be addressed by the professional qualified to help.
With all the components of a comprehensive band program-the doctor to make adjustments to the band, the dietitian to act as an eating guide, the exercise therapist to provide coaching and encouragement to exercise, and a psychologist to help patients change their thinking-the band becomes the number one tool to create an environment in which it is much easier for patients to treat themselves well and make smart choices. Overall, the band is the tool to help weight-loss patients break the cycle of failure.
Using the AGB as a Behavior Modification Tool
The ability of the AGB to restrict the amount of food, along with the absence of hunger, makes it sound like a magical solution to the problem of obesity. However, it is not quite that easy.
It has often been said that the definition of insanity is doing the same thing over and over again and expecting a different result. That is particularly applicable when we look at all of the various things people do in an attempt to lose weight. The fact is that nothing works unless it is accompanied by a true change in behavior and a corresponding change in lifestyle. The key to successful weight loss with the AGB lies in how each individual patient uses it as a tool to effect those changes.
The AGB is not a diet, at least not in the usual sense of the word. When the band is properly adjusted, you should be able to eat virtually any food you just can't eat as much. Making good food choices becomes crucial to ensuring proper nutrition. But weight-loss success with the AGB is ultimately linked more to the way you eat than what you eat.
Willpower alone is rarely sufficient to overcome the strong human tendency to resume comfortable behavior patterns developed over many years. To effect a major change generally requires both positive feedback from the new behavior, and a significant penalty for continuing the old behavior.
The AGB provides continuous restriction, offering immediate negative feedback for undesirable eating behavior. If you eat too fast, take a bite that is too big, or attempt to overeat, the band will let you know. It acts like an unseen "drill sergeant" providing continuous discipline. That is why we have affectionately come to refer to our Comprehensive Weight Management Program as "Dietary Boot Camp."
If you don't eat slowly and chew all foods thoroughly, the band will make you miserable. A bite that is too large or not adequately chewed will feel like it is hung up. The trapped food causes the esophagus to contract vigorously in an attempt to push the bite through the narrow opening created by the band. This spastic contraction is very uncomfortable and is usually felt in the chest. The pain often radiates into the back or up into the neck. It is usually accompanied by the production of a large amount of foamy mucus, which quickly builds up in the esophagus above the blockage. Salivation can also increase in the mouth as the body attempts to provide lubrication. Some band patients call this "sliming."
Eventually, the mucus, along with some or all of the recently swallowed food, will come back up. This is not really vomiting, and doesn't contain much, if any, digestive acid. It is more of a spontaneous regurgitation. Some patients refer to this spitting up as a "productive burp."
The same symptoms will occur if you eat too fast. Even small bites will be a problem if they aren't chewed thoroughly. With the AGB, it becomes critical to take your time while eating. I recommend that you get in the habit of setting your fork or spoon down on the table after each bite. This conscious effort serves as a reminder to slow down. If you don't, the "drill sergeant" will remind you.
Checklist: Tips to Successful AGB Eating
✓ Take your time to eat.
✓ Take small bites, about the size of the tip of your index finger.
✓ Chew each bite thoroughly.
✓ Put your utensil down between bites while you chew.
Virtually every patient who has a band has experienced the pain associated with eating too fast or taking bites that are too large. Most have also endured the embarrassment of having to excuse themselves from the table as the bite they just swallowed comes back up. While unpleasant, for many this is precisely the motivation they need to change their old eating habits.
Summary
The adjustable gastric band is a weight-loss tool. First, it must be properly placed. Then it must be appropriately adjusted. Finally, it requires continuous monitoring and support as new eating behaviors lead to a change in lifestyle.
In addition, there is a clear distinction between the AGB and procedures that we typically classify as bariatric surgery. With this tool, weight loss is not automatic, but occurs only with significant behavior modifications and lifestyle changes. In the next two chapters we will explore who is a suitable candidate for the AGB and why-as well as what kind of support programs are needed to achieve long-term success.