Roux-en-Y Gastric Bypass

Excerpt

The prevalence of obesity continues to rise with the United States of America (USA) currently ranking second in the world. According to CDC data, in 2015-2016, the prevalence of obesity (BMI greater than or equal to 30) was 39.8% affecting approximately 93.3 million adults in the United States. Almost 5% of the population was extremely obese (BMI greater than or equal to 40). Obesity predisposes to multiple comorbidities, including type 2 diabetes, cancer, hypertension, hyperlipidemia, obstructive sleep apnea, heart disease, and increased risk of stroke gastroesophageal reflux disease (GERD), osteoarthritis, and non-alcoholic steatohepatitis. The annual estimated medical cost of obesity in the USA was $147 billion in 2008, with the cost for an individual with obesity being $1,429 higher than those of healthy weight, representing a massive financial burden. The United Kingdom National Health Service estimates the cost of managing the obesity-related disease at 5 billion pounds (2 billion kg) per year, set to increase to 10 billion pounds (4.5 billion kg) by 2050.

Treatment options for obesity include nonoperative management or bariatric surgery. The nonoperative management is a multimodality approach, including dietary changes, increasing physical activity, behavioral modifications, and pharmacotherapies. Dietary and exercise advice has little proven benefit for the majority. A cross-sectional study assessing 109000 people in the USA using Behavioral Risk Factor Surveillance found that while the majority of people were attempting to lose weight, only 20% can reduce their energy intake and do 150 minutes of exercise per week. Long term results of medical management in maintaining weight loss have been poor with average weight loss reported to be of only 4%.

Different options for bariatric operations are malabsorptive, restrictive, or both and include Roux-en-Y gastric bypass, sleeve gastrectomy, and gastric banding. In a meta-analysis evaluating 11 studies with 796 patients (BMI range 30-52), individuals allocated to bariatric surgery lost more bodyweight with a mean difference of 26 kg compared to those treated with non-surgical management. Researchers noted that the surgical group had a higher remission rate of type 2 diabetes, lower plasma triglyceride, greater improvement in the quality of life, and reductions in medicine use.

Roux-en-Y Gastric bypass is a restrictive-malabsorptive procedure that was introduced in 1966 by Mason. It accounted for over 60 to 70% of all bariatric operations in the United States since 2003. However, FDA approval in 2001 has led to a slow uptake of banding, which in 2011 exceeded bypass (46% vs. 44%) in estimated figures. Sleeve gastrectomy is the next most commonly performed operation (7.8%) becoming increasingly popular in modern practice due to its lower risk profile and similar outcomes to bypass. Developments in laparoscopy across all fields of abdominal surgery have led to laparoscopic bariatric procedures now accepted as the standard of care. The low morbidity and mortality associated with laparoscopic procedures have led to the introduction of day-case surgery for bypass and gastrectomy procedures, establishing bariatrics as a cost-effective intervention.

Obesity is defined by WHO according to body mass index - BMI (kg/m^2) 18.5 to 24.9 normal range, 25 to 25.9 overweight (pre-obese), 30 to 34.9 obese class I, 35-35.9 obese class II, 40 to 49.9 obese class III.