WEIGHT LOSS OPTIONS: Bariatric Surgery Update

Gregg Jossart, MD, FACS

In 1995, surgeon Walter Pories published an article in the Annals of Surgery titled, “Who would have thought it? An operation proves to be the most effective therapy for adult-onset diabetes mellitus.” Almost two decades later, the United States is in the middle of an obesity-related diabetes epidemic. More than 100 million Americans have diabetes or prediabetes, and more than 70 million are obese.

Two-thirds of adult-onset diabetes is directly associated with obesity. Obesity is also associated with more than 40 other medical problems, such as heart disease, cancer, sleep apnea and orthopedic issues. All of these problems, including the obesity itself, tend to worsen with time. Although the problems can be treated to some extent with medications, CPAP devices and physical therapy, the core problem that remains is the obesity. Diet and exercise are always the best starting point for obesity, but failure does occur, and the obesity persists.

Obesity surgery has the highest cure rate for obesity and its related illnesses, but it has long been viewed as a last resort and thought to be dangerous. That view is changing because of newer, safer procedures and how well diabetes is cured with surgery. In April, the American Association of Clinical Endocrinologists recommended obesity surgery as an earlier treatment option in the obesity disease process. Surgery has the highest cure rate when obesity-related diabetes is in the earliest stage--not when a patient has had diabetes for 10 or more years and is approaching 400 or more pounds in weight.

In the last 20 years, numerous advances have occurred that make surgical weight reduction an earlier option in the treatment of obesity and diabetes. The main advances are the laparoscopic approach, increased safety and lower-risk procedures. The evolution from open to laparoscopic surgery began in 1994, and now almost all weight-loss surgery is performed laparoscopically. Laparoscopic patients have less pain and fewer complications, and they usually require only one night in the hospital. Both the laparoscopic approach and increased surgeon experience have reduced complication rates to the point that bariatric surgery has been proven to be safer than even gallbladder surgery.

The two methods of surgical weight reduction are restriction and malabsorption. Restriction reduces oral calorie intake by decreasing the size of the stomach. All current bariatric surgical procedures include some degree of restriction. In the gastric band procedure, a silastic (silicone rubber) band that acts to restrict food is placed around the top of the stomach. In a sleeve gastrectomy, staples are used to reduce the size of the stomach.

Malabsorption is a more complex technique that involves both restriction of the stomach and rerouting of the small intestine. In the gastric bypass, the stomach is divided to create a small pouch that is connected to the small intestine. In the duodenal switch, the stomach is restricted as in a sleeve gastrectomy and a large amount of intestine is rerouted so that only a short segment carries food and the bypassed segment carries the digestive juices.

All four of these procedures achieve weight loss and diabetes resolution, and all are approved by insurance companies. Malabsorption can achieve a more durable weight loss and perhaps a better cure for diabetes, but it may also yield more long-term nutritional deficiencies and other complications related to the intestinal bypass.

The sleeve gastrectomy (or gastric sleeve) reduces stomach volume without changing the intestines or using a foreign body (the gastric band). This type of reduction allows for a balance between portion size and range of food choices, with fewer side effects. The proportion of sleeve gastrectomies in American bariatric surgeries has increased from 2% in 2008 to 44% in 2012; insurance companies started approving sleeve gastrectomies in 2010.

Sleeve gastrectomies are particularly appealing to patients because they avoid all the potential problems of the more complex bypass operations as well as the foreign-body problems of gastric banding. The weight-loss and diabetes cure rates for sleeve gastrectomy are similar to the bypass operations, with a much lower risk profile. Historically, surgeons were slow to offer sleeve gastrectomy to patients as it involves removing most of the stomach and is not reversible. They also thought weight loss would be inadequate or weight gain would occur because the operation only reduced stomach volume.

Results over the last five years, however, have proven that sleeve gastrectomy yields durable weight loss and diabetes improvement.[1] There is also some proof that removing the volume part of the stomach (greater curvature) also removes most of the cells that produce ghrelin, the hunger hormone.[2] This phenomenon may explain why sleeve gastrectomy has better than expected weight-loss results. Overweight diabetic patients who choose sleeve gastrectomy are delighted with the reduction in appetite; the early and lasting fullness after small portions of food; and the rapid improvement in their diabetes, to the point where they no longer need insulin or even oral medications.

Critics of sleeve gastrectomy claim it has not been studied well enough yet and that without an intestinal bypass the results will be inadequate. Medicare and most insurance companies, however, have decided that sleeve gastrectomy is effective. The lack of an intestinal bypass may actually be what makes sleeve gastrectomy so appealing to patients. Despite all these benefits, however, both physicians and patients need to realize that sleeve gastrectomy is most effective and safe at lower levels of obesity (BMI <55) and within the first few years of a diabetes diagnosis.

Dr. Jossart, a bariatric surgeon, has offices in Novato and San Francisco.

Email: jossarg@sutterhealth.org

References

1. Mechanik JI, et al, “Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient,” Obesity, 21:S1-27 (2013).

2. Langer FB, et al, “Sleeve gastrectomy and gastric banding: effects on plasma ghrelin levels,” Obes Surg, 14:1024-29 (2005).