Roux-en-Y Gastric Bypass

Excerpt

The obesity epidemic has reached alarming proportions globally, making it one of the most pressing public health concerns of our time. The World Health Organization defines obesity according to body mass index (BMI): 18.5 to 24.9 kg/m² is the normal range, 25 to 25.9 kg/m² is overweight (preobese), 30 to 34.9 kg/m² is obese class I, 35 to 35.9 kg/m² is obese class II, 40 to 49.9 kg/m² is obese class III. Super-obesity is a BMI greater than 50 kg/m^2, and super-super obesity is a BMI greater than 60 kg/m² as classified by the International Bariatric Surgery Registry. Results from a recent study published in Lancet revealed that more than 1 billion adults and children around the world are now obese; nearly 880 million adults, as well as 159 million children, are living with obesity. Obesity rates for children and teenagers quadrupled worldwide between 1990 and 2022, rising from 1.7% to 6.9% for girls and 2.1% to 9.3% for boys. Meanwhile, adult obesity rates more than doubled during the same period. Obesity increased more than 2-fold in women (8.8% to 18.5%) and nearly tripled in men (4.8% to 14%).

Multiple study results have established a strong association between obesity and mortality. An extensive prospective cohort study investigating the association between BMI and mortality determined that a higher BMI was associated with an increased risk of death, particularly among nonsmokers and people aged 50 years or older. Numerous medical conditions such as diabetes, metabolic dysfunction-associated steatotic liver disease (formerly nonalcoholic fatty liver disease), gastroesophageal reflux disease, gallbladder disease, cardiovascular disease, hypertension, dyslipidemia, endocrine changes, musculoskeletal disorders, sleep apnea, cancer (breast, pancreatic, stomach, endometrial, and colorectal), and pulmonary complications have been linked to obesity. Additionally, obesity has a detrimental influence on psychological functioning and health-related quality of life and is related to increased rates of stigmatization and discrimination.

Furthermore, the estimated medical cost of adult obesity in the United States (US) ranges from 147 billion to nearly 210 billion dollars annually, with the cost for an individual with obesity being 1429 dollars higher than those of healthy weight; this represents a massive financial burden. The United Kingdom National Health Service estimates the cost of managing obesity-related disease at 5 billion pounds (6.5 billion US dollars) per year, set to increase to 10 billion pounds (13 billion dollars) by 2050. The compelling evidence linking obesity to mortality and various medical conditions, as well as the massive strain on the healthcare systems, has driven the demand for effective treatments.

Various treatment modalities have been developed to address the challenges posed by overweight and obesity. These include bariatric surgery, weight loss-inducing medications, and lifestyle modifications. Lifestyle changes are not yet as successful as bariatric surgery for treating class III obesity. Although success is achieved with lifestyle changes in the short term, patients' long-term noncompliance with diet or inability to maintain physical exercise prevents weight loss in patients. Medical treatments have been tried, and their studies are still ongoing. Semaglutide has provided promising results for medically treated obesity and may open new horizons depending on long-term results. Although behavioral and pharmaceutical therapies for obesity may result in a short-term weight loss of around 5% to 10% of body weight, their long-term effectiveness is still restricted. Following these therapies, weight gain frequently happens between 6 and 24 months later, along with a decline in health-related gains.

On the contrary, bariatric surgery can result in significant and long-lasting weight loss, anywhere between 50% to 75% of extra body weight, with some study results showing weight maintenance up to 16 years after surgery. Bariatric surgery also is currently the most effective treatment for class III, super, and super-super obesity and its related comorbidities. As a result, the number of bariatric procedures being performed worldwide is constantly rising. The continuous rise of bariatric surgery procedures has also been significantly influenced by increased awareness among patients and physicians, media attention highlighting celebrity patients' experiences, extended coverage by health insurance companies and third-party payers, and increased surgery safety with shorter hospital stays through the advent of laparoscopic procedures.

Bariatric surgical procedures can be classified into 3 main categories based on their functions: restrictive, combined (restrictive and malabsorptive), and primarily malabsorptive. These procedures aim to achieve weight loss through different mechanisms. Restrictive procedures include laparoscopic adjustable gastric banding, vertical banded gastroplasty (no longer performed due to high complications), and sleeve gastrectomy. Malabsorptive procedures include jejunoileal bypass, which is no longer performed due to considerable mortality related to starvation and organ failure. Combined restrictive and malabsorptive procedures include RYGB and biliopancreatic diversion with a duodenal switch.

RYGB was first introduced in 1966 by Mason, and after significant evolution, it is now accepted as a reliable bariatric surgery method with long-term results. Developments in laparoscopy across all fields of abdominal surgery have led to laparoscopic bariatric procedures being 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. Currently, sleeve gastrectomy and RYGB are the bariatric procedures most commonly performed worldwide.