05/03/2011 11:12 am ET | Updated Jul 03, 2011

Weight-Loss Surgery Requires Careful Consideration

While inching through the Los Angeles rush hour, you can barely creep a mile without hearing that ubiquitous radio ad jingle or seeing a billboard proclaiming that with weight-loss or bariatric surgery, a new, thinner life could be just a phone call away.

Although bariatric surgery remains one of modern medicine's best weapons in the fight against obesity, the choice by patients to undergo the array of possible procedures must be taken with great gravity.

The best bariatric surgery centers evaluate patients in many different ways, weighing the status of their medical, surgical, nutritional and mental health. This gives experts a full picture of an individual's situation and can be critical in deciding which weight-loss surgery -- if any -- would be proper. This contradicts a common misconception that bariatric surgery is the "easy way" to lose weight. The public also seems unaware of crucial differences among available procedures: there's more to it than deciding if you want a band or a bypass.

The option became available to more Americans than ever before, when the Food and Drug Administration recently ruled that doctors may offer the adjustable gastric band, or LAP-BAND, surgery to those with a Body Mass Index -- a measure based on height and weight -- of 30 and at least one additional serious weight-related health problem like diabetes or heart disease. The number of patients now eligible for this surgery has jumped from an estimated 15 to 18 million to 26 million.

Previously, a 5-foot-10 patient needed to weigh a minimum of 243 pounds or so and have a condition such as high blood pressure or diabetes to qualify for the banding procedure. Now, that same patient could weigh in at 209 or so to be eligible if she also carried other weight-related health risks.

There are different bariatric surgery options available -- with distinct differences for each. What they share in common: they should be considered only after other weight-loss measures -- such as diet and lifestyle modifications -- have failed. They also each require behavior changes, including eating less, especially at one sitting. If a person consumes more food than her newly smaller stomach can hold, she can expect to experience vomiting, nausea, diarrhea, dehydration and stretching of the pouch - potentially reversing the surgery's benefit.

The available procedures are classified into restrictive, in which the stomach is made smaller, malabsorptive, where some of the areas of the small intestine where food is absorbed is bypassed, or a combination. These procedures include:

Adjustable Gastric Banding

In the adjustable gastric band technique, surgeons position an inflatable silicone belt around the stomach, creating an egg-sized pouch. The band is adjusted by injecting saline into a port just under the skin. For the first 18 months after the surgery, the band is adjusted every six weeks or so, then once or twice a year thereafter.

Even if they meet its eligibility requirements, that still doesn't mean this type of weight-loss surgery is a patient's best match. The band merely creates a smaller stomach pouch. So, patients who devour lots of soda, alcohol or other liquid calories, or soft foods like ice cream won't benefit because of the band alone, as those consumables' calories will slip right through. The band does tend to help patients shrink their BMI 10 to 13 points. A recent five-year study, used to win approval for the band for less obese patients, showed that nearly 84 percent of patients lost at least 30 percent of their excess weight. More than 65 percent were no longer obese after a year and kept that weight off in the study's second year. However, over 70 percent of the patients experienced mostly mild to moderate side effects such as vomiting and difficulty swallowing, that generally resolved within a month.

Band patients also often see improvement in obesity-related conditions like diabetes or hypertension after they've lost weight - usually within a year or so of surgery.

Gastric Bypass Surgery

Gastric bypass works in three ways. First, the stomach is made smaller by closing off part of it with staples, leaving only a small pouch. Like banding, this smaller stomach causes you to feel fuller faster. Second, the food bypasses part of the small intestine, meaning fewer calories get absorbed from food.

Third, the surgery affects the body's hormones in ways that scientists still are researching. It's unclear exactly how or to what degree various hormones are affected. Some effects take time to appear, others more swiftly. In patients who have only had diabetes for five years or so and who ingest medications and not insulin injections, their insulin levels begin improving almost immediately after surgery.

One of the hormones under scrutiny is ghrelin, which triggers hunger in the brain. Before a meal, its levels jump, then are suppressed after eating. In those who lose weight without surgery, ghrelin levels tend to increase, causing more hunger. In bypass patients, levels of this hormone seem to flat-line, which could contribute to reduced hunger. One theory why this happens is that the part of the stomach that produces this hormone doesn't come into contact with food.

Sleeve Gastrectomy

This is one of the newest bariatric techniques. While gastric bypass has been around for more than 30 years, and banding for more than a decade, surgeons have done laparoscopic sleeve gastrectomy on its own for three years or so. It initially was the first in a two-part bariatric surgery, but it was shown to be a successful procedure on its own. In this surgery, 85 percent or so of the stomach is removed, leaving the patient with a long, narrow sleeve-shaped organ.

Like bypass, it works both by decreasing stomach size and on a hormonal level -- but patients still will absorb all the calories from food they eat.

In summary, bariatric surgery isn't cosmetic. These can be lifesaving procedures for patients with serious health conditions. In many cases, these weight-loss surgeries can reverse diabetes, decrease the risk of various cancers and heart disease, and lead to an overall improvement in health. A Swedish study also demonstrated that for patients with severe obesity, there is a decrease in overall mortality. Although laparoscopic techniques have made it possible to recover sometimes from these surgeries in just days, they require a deep commitment to be successful. The choice of surgeons and hospitals is very important. The lowest risks are found with surgeons who perform more than 100 bariatric operations each year and in hospitals whose volume of these surgeries exceeds 150 operations each year. Look for a program that offers education and support, both before and after the surgery. When your post-surgical life begins, it will include more than new clothes and a new, narrower waistline. It will mean new behaviors and ways of eating that must last a lifetime.