decision surgery

Having surgery to alter the way you digest your food is not a decision to be taken lightly. But it is one that more and more people who are severely obese are weighing now that safer and more effective obesity surgery is available to them.

About 3 percent of American adults are considered severely obese. People are considered severely obese when they have a body-mass-index (BMI), a measurement that compares your weight and height, of 40 or more. This usually means they are about 100 pounds overweight.

People who are this heavy are often disabled by their extra weight and face a host of medical conditions and even a shortened lifespan. But surgery can be lifesaving, says Marc Bessler, MD, FACS, the director of the New York–Presbyterian Center for Obesity Surgery at Columbia University Medical Center.

"There are centers doing safe operations with good results and anybody who's suffering with this disease needs to at least think about it," Dr. Bessler explains.

If someone decides to have surgery, they will need to figure out which operation is best for them and whether they will be able to adopt new eating habits after a surgery that has made their stomach smaller and/or changed the way that their body absorbs food. Read on for Dr. Bessler's review of the risks and benefits of the different surgical options, including laparoscopic gastric banding, also know as Lap-Band, and gastric bypass.

Who is a candidate for obesity surgery?
It depends on the type of surgery, but the standard criteria are being 100 pounds over ideal body weight or 80 pounds over ideal body weight if someone also has medical conditions due to the obesity, such as diabetes, high blood pressure, sleep apnea syndrome or others.

Pretty much anybody who is going to be accepted for surgery will have tried and failed to maintain weight loss with diet. They also won't have any absolute contraindications to surgery, such as uncorrectable bleeding disorders, unmanaged psychiatric disorders or active drug abuse or alcoholism. They will understand what they need to do after surgery and be willing to make the lifestyle changes that these operations require. They will commit to long-term follow-up.

What are the leading types of surgery?
The most common surgery for obesity is gastric bypass. Probably the next most common surgery in the United States is adjustable gastric banding, which is a safer operation but doesn't achieve as much weight loss and requires a little bit more work on the patient's part.

Both operations can be done laparoscopically. That means making five or six small incisions in the abdomen and a inserting a scope to visualize and perform the operation. There's another procedure called biliopancreatic diversion, or duodenal switch, which is more complex than either of those and isn't very commonly performed.

What does gastric banding involve?
Gastric banding, which is called a Lap-Band when done laparoscopically, is a purely "restrictive" operation where a band goes around the top of the stomach. We can adjust the band in the office with a needle that goes under the skin that allows us to inject fluid into the band. The more fluid in the band, the tighter the band will be.

This operation works by limiting, or restricting, the amount of solid food that a patient can eat by making them feel full quicker when they eat solid food. This procedure however, does not do anything to limit high calories from liquid or junk food. These foods will pass right through relatively unrestricted and then get absorbed, so patients have to voluntarily stay away from those foods.

Some patients clearly do better with this surgery, some do worse. For example, eating too much or not chewing food well can cause vomiting, so some patients deal with this by taking the easy way out, which is to have liquid calories or soft foods.

What does gastric bypass involve?
The gastric bypass is a more complex operation. The stomach is divided into two parts using a stapler, creating a small upper pouch and a large lower pouch. We then bring up a limb of intestine and sew it to that smaller stomach pouch so it empties from a small opening directly into the intestines. The large pouch is bypassed so food doesn't get partially digested before going into the intestine. This procedure also causes early satiety and a hormonal reaction that may cause less food intake causing the patient to eat less and lose weight.

One of the side effects from this surgery occurs when food moves too quickly though the intestine, usually from having sweets and fats. So if a patient has a couple scoops of ice cream after a gastric bypass, they will get what we call dumping syndrome. This causes lightheadedness, dizziness and a sense of tiredness. If they eat too much fat, they can get abdominal cramps and diarrhea. So this operation does not limit solid food intake as tightly in the long run as banding surgery, but it has a force that keeps you away from the sweet and junk foods.

What is a biliopancreatic diversion?
Biliopancreatic diversion, or another version of the operation called duodenal switch, involves removing three-quarters of the stomach and bypassing more of the intestine than you do with a gastric bypass. So it is more dramatic. It has more risks of complications upfront and it has significantly more risk of nutritional consequences because you are not able to absorb enough of the main nutrients that your body's needs, especially proteins.

However, since it leaves a little bit bigger pouch of stomach patients can tolerate larger volumes of food. It may have better long-term weight loss for heavier patients, because it doesn't allow you to absorb as much of the food that you eat. And there's no dumping syndrome. It's potentially more risk, but if it causes more weight loss, then it may be appropriate for some patients. Duodenal switch is really offered only to the most driven patients who are able to afford the $1300 a year in supplements that you need to prevent vitamin and mineral deficiencies after this operation.

What are other surgical options?
One interesting newer option is a sleeve gastrectomy, where you only do that first portion of the biliopancreatic diversion. You remove the three-quarters of the stomach, leaving a sleeve of stomach, but you don't do the intestinal portion of the surgery. Some surgeons are using that as a first stage to get higher-risk patients to lose weight and then come back and do the rest of the operation at a second stage so they can lose more weight.

How much weight loss can people expect to see with surgery and how quickly does that happen?
With Lap-Bands, people can expect to lose approximately 50 percent of excess weight. So if they are 100 pounds overweight, they can expect to lose 50 pounds. That weight loss takes approximately two years. With the gastric bypass, patients with a BMI under 50 seem to lose 70 percent of their excess weight or more. Patients who have a BMI over 50 tend to lose about 50 percent of their excess weight with a gastric bypass. I'd say three-quarters of the weight loss happens in the first six months and almost all of it by a year to 18 months.

What do you take into consideration when choosing an operation?
In general, the more weight loss someone wants, the more risk they have to be willing to accept, so the right surgery depends on what their goals are for weight loss. For example, gastric bypass is associated with a 1 in 50 to 100 risk of death. Adjustable gastric banding is a safer operation. That operation probably has a less than 1 in a 1000 risk of death.

In patients who are older or sicker, we generally tend toward either the banding or sleeve procedure. Those operations are good for people who are unwilling to accept the risk of the gastric bypass, people who are volume eaters and higher-risk patients who we want to offer a lower-risk operation.

Is there a risk of becoming undernourished?
Nobody should go to a surgeon who does bariatric surgery without a program that delivers pre-operative and post-operative nutritional support. With Lap-Bands, there's almost no risk of becoming undernourished as long as chronic vomiting doesn't become a problem. With gastric bypass, there are certain vitamins and minerals (iron, calcium, vitamins B12 and D) that can be poorly absorbed after the surgery, so we recommend supplements.

With biliopancreatic diversion, 2 to 10 percent of patients can end up with protein malnutrition that requires intravenous nutrition and then further surgery to allow the patient to absorb more of their proteins. Up to a third of patients can end up with vitamin or mineral deficiencies. These patients have to be even more carefully followed and even stricter about their diet.

How can people choose a good bariatric surgeon?
You want to know that they're at a center that offers not just bariatric surgical services, but critical care services and excellent anesthesia and everything else that goes with it. Number two, make sure that the surgeon is working with a program that's multidisciplinary, so they have a nutritionist on staff and other support staff like a physician or a nurse practitioner to help manage the medical end of this surgery for the long term. Number three, the center should do more than one type of operation so they're not offering the same type of surgery to every patient.

The surgeon should have fairly extensive experience. There is a learning curve with these operations, especially if done laparoscopically, so look for someone who has done an excess of 200 operations and who answers your questions honestly and takes the time to evaluate and educate you carefully, so that it's not a big shock afterwards. "Oh, you mean I needed to eat pureed foods," or, "I couldn't eat this," or, "I have to take that vitamin."

I think patients rush into this sometimes. They make a decision in their head and then it's wherever I can get this done soonest. But the goal is long-term health and quality of life in addition to weight loss.

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