Weight-loss Surgery Options
Dr. Mark Yamamura
Chief of general surgery at Kaiser Permanente
Where did you receive your schooling/training?
I did my undergraduate training at Northwestern University in Evanston, near Chicago. For medical school I went to the University of Arizona in Tucson, where I also completed my general surgery residency. I did my fellowship in minimally invasive surgery at Oregon Health and Science University in Portland.
How long have you been in practice?
I have been in practice for 14 years. I joined Kaiser Permanente in 2000.
What made you decide to enter the field of bariatric surgery?
I was always interested in obesity as a medical problem, but what especially interested me was the ability to perform bariatric operations using minimally invasive surgical techniques. Ninety-nine-plus percent of bariatric procedures are done using minimally invasive or laparoscopic techniques.
Does bariatric surgery comprise a number of weight-loss surgeries?
We now use the term “bariatric and metabolic surgery” because we’re finding that the operations we’re doing are affecting weight loss through metabolic changes. Bariatric and metabolic surgery encompasses a number of procedures. The most popular of these are the laparoscopic gastric bypass, the laparoscopic sleeve gastrectomy and, previously, the laparoscopic gastric band, though the band has become a less popular option in the past several years.
Which is the most popular procedure and how does it work?
The gastric bypass is the most popular. With the laparoscopic gastric bypass, we take the stomach, which is about the size of a football when it’s full, and convert it down to about the size of a small egg. Then we reconnect the intestines to compensate for making the stomach smaller. The operation shrinks the stomach and alters the hormones that regulate hunger and fullness. This combination leads to weight loss.
With the laparoscopic sleeve gastrectomy, another very popular procedure, the stomach is made into the shape of a skinny banana. We’re not disconnecting the intestines, but we’re removing about two-thirds or three-quarters of the stomach.
How do these procedures change things metabolically?
We’re seeing that the neurohormonal changes associated with these operations are what drives weight loss. For example, a hormone called ghrelin is decreased after the gastric bypass or gastric sleeve. And there is an increase in the hormone peptide YY, which has to do with causing fullness or satiety. Ghrelin is a hormone which causes hunger. Typically, if someone were to go on a diet, their ghrelin level would go up, causing them to feel very hungry all the time. They actually gain more weight than they originally lost because the ghrelin levels stay elevated for quite a long time, even though they’ve already regained the lost weight. With bariatric surgery, we see a decrease in that ghrelin level.
Who is the best candidate?
A candidate should have a BMI or body mass index of greater than 40, or 35 or greater if they have an existing comorbidity such as prediabetes, diabetes, hypertension, sleep apnea, etc.
BMI is your weight in kilograms divided by your height in meters squared.
How much weight is usually lost?
Based on our data, we expect people to lose between 50 to 70 percent of their excess body weight and maintain that for the rest of their life. Excess body weight is the difference between your current body weight and your ideal body weight.
How long does it take to heal?
Typically, after laparoscopic surgery, it takes a couple of weeks for most of the incisions to look like they’re partially healed. It takes a full six weeks to really be healed.
What does it take to maintain oneself post-surgery?
We promote lifestyle changes consisting of proper diet and exercise, which are the keys to succeeding after any bariatric operation. For our patients, it’s eating five or six small meals consisting mainly of protein and complex carbohydrates, and getting a proper combination of healthy fat. The other change that’s critical to maintaining weight loss is exercise. Dietary changes are crucial for losing the initial weight, but then to maintain it exercise is extremely important.
Beyond losing pounds, what are the other health benefits of bariatric surgery?
A significant improvement in diabetes is the most fascinating benefit we see. It’s amazing because the next day, even before the patient has lost any significant amount of weight, we see a rapid improvement in their diabetes control.
What’s also interesting, from the standpoint of practicing in Hawaii, is that Asians are at risk of developing diabetes at a lower BMI than Caucasians or African Americans. In other words, if it’s typically a BMI of 30 that would put a Caucasian or African American at risk of developing diabetes, a BMI of 27 could be putting a person of Asian descent at risk.
How many bariatric operations do you do a week?
About four operations a week, about 150 a year.
To what extent is bariatric surgery a last resort?
Most of our patients have tried various diets and exercise. We know from national data that only about 10 to 15 percent of folks who start implementing those changes are really able to achieve long-term weight loss success. The overwhelming majority of patients are not able to succeed with just dieting and exercise. For these patients, a bariatric operation may be the best option.
Is there an evaluation ahead of time to be sure the patient is likely to maintain the necessary regimen?
At Kaiser Permanente, we have an extensive pre-surgery program that teaches people good habits and educates our patients on what to expect and how to succeed. The support group program, the nutritional and behavioral education, as well as meeting with their bariatric primary care physician are crucial elements to help our patients succeed before and after the operation.
We are proud of the fact that two of our bariatric primary care physicians, Dr. Peggy Latare and Dr. Ben Tamura, are board certified as practitioners of obesity medicine. We’re also proud to be certified through the Metabolic and Bariatric Surgery Assessment Quality Improvement Program (a joint program of the American College of Surgeons and the American Society for Metabolic and Bariatric Surgery), which is a standard of excellence.