By June Levine, MD
Ever since the first sleeve gastrectomy was performed in 1990, it has become one of the most popular bariatric surgeries in the world. It has even changed our notion of what bariatric surgery means, but more importantly, it has given bariatric patients another option to consider in their battle against obesity.
It’s critical to remember that obesity is a chronic disease. The rate of obesity in adults is at 37.9% with similar rates in children and adolescents, according to the NHANES . When the CDC provided their May 2017 updates, 71.6% of American adults were overweight . Obesity is an independent risk factor for development of different chronic conditions, including diabetes, cardiovascular disease and some cancers .
Currently, bariatric surgery is the most effective treatment for patients with morbid obesity. The Roux-en-Y gastric bypass is considered the gold standard operation for bariatric surgery, with established outcomes. However, the sleeve gastrectomy has risen in popularity in the last ten years. There is a scarcity of studies with a head-to-head comparison of the sleeve gastrectomy to the Roux-en-Y gastric bypass. There are only a few five-year outcome trials, but no long-term studies.
Both procedures restrict the amount of food that is consumed. But the gastric bypass also has a malabsorption component. The sleeve gastrectomy removes 80% of the stomach, whereas the gastric bypass partitions the stomach into a small pouch and the small intestine is reattached to the pouch, bypassing the duodenum. The sleeve gastrectomy procedure is a more technically simple operation to perform. The procedure can be done faster and has a shorter learning curve for surgeons. In terms of its safety profile, it is potentially a safer procedure than the gastric bypass.
Traditionally, the gastric bypass has been considered a more superior procedure than the sleeve gastrectomy. Using a side-to-side comparison, the short and mid-term studies show a better profile for both weight loss and comorbid conditions such as diabetes, hyperlipidemia and acid reflux with the gastric bypass. However, in two recent five-year studies, the weight loss and remission of medical conditions were comparable with sustained weight loss for both procedures [4,5]. Specifically, five-year remission rates for diabetes, improvement in quality of life and complication rates were similar.
There are key differences that set them apart, however. Firstly, is the high rate of worsening gastric reflux symptoms in the sleeve gastrectomy, whereas it is significantly better treated in the gastric bypass. Moreover, what is concerning is the new onset of acid reflux in patients who did not have baseline acid reflux, after sleeve gastrectomy. Most patients can be treated conservatively with medications, but about 10% of these patients require surgical intervention to the gastric bypass to address the acid reflux . Barret’s esophagus occurs in 17% of sleeve patients  with the incidence of cancer in 0.3 – 2.4% . Secondly, in terms of diabetes, although there was no statistical significance with either procedure, the picture is still unclear. In most of trials, there is a significance in favor of gastric bypass for diabetes for long term outcomes and in regard to the number of diabetic medications needed. These studies were not done for a diabetic endpoint; hence the data is extrapolated. Thirdly, is that follow up is poor. We may not be seeing patients return due to weight regain and hence we do not see the full picture of the rate of recidivism for either procedure.
So, while both the gastric bypass and the sleeve gastrectomy are very effective in weight loss and amelioration of comorbid medical conditions, there are some very specific complications associated with each procedure. Both surgeries have made patient outcomes better over the years. So they should continue to be thought of as two separate, but needed, tools to fight obesity.