Bariatric surgery

Learning objectives

Bariatric or weight loss surgery limits the amount of food a patient can comfortably eat or decreases the absorption of food and calories
It is used as a later treatment option for obesity and helps to improve obesity-related conditions
- Hypertension
- Hyperglycemia
- Diabetes mellitus type 2
- Hypercholesterolemia
- Cardiovascular disease and stroke
- Kidney disease
- Obstructive sleep apnea
- Osteoarthritis
- Non-alcohol-related fatty liver disease

Classification

Adjustable gastric band: Placement of an inflatable silicone band around the top portion of the stomach
Gastric bypass surgery (e.g., Roux-en-Y gastric bypass): The stomach is divided into a small upper pouch and a much larger lower “remnant” pouch, and the small intestine is rearranged to connect to both
Sleeve gastrectomy or gastric sleeve (irreversible): The stomach is reduced to 15% of its original size via surgical removal of a large portion of the stomach along the greater curvature

Each procedure exerts its effects through at least one of the three mechanisms → procedures often affect several of these mechanisms

Restricting: Restricting food intake (e.g., gastric sleeve)
- Reduce the size of the stomach that is available to hold a meal
- Filling the stomach faster enables the individual to feel more full after a smaller meal
Blocking: Decreasing nutrient absorption (e.g., Roux-en-Y gastric bypass)
- Reduce the amount of intestine that the food passes through
- Reduces the ability of the intestines to absorb nutrients from the food
Mixed: Affecting cell signaling pathways
- Alter hormones responsible for hunger (e.g., ghrelin) and satiety (e.g., leptin)

Any age
Males and females equally affected
Increased incidence of
- Diabetes mellitus
- Cardiovascular disease
- Respiratory disease
- Sleep apnea syndrome

Excess skin folds
Malabsorption and malnutrition (e.g., vitamin and mineral deficiencies)
Bile reflux
Gallstones
Kidney stones
Blood clots in the leg (i.e., deep vein thrombosis) or lungs (i.e., pulmonary embolism)
Infection
Hernias
Small bowel obstruction
Anastomotic leaks
Dumping syndrome
Hypoglycemia
Ulcers
Vomiting
Gastroesophageal reflux disease
Metabolic bone disease (e.g., osteopenia and secondary hyperparathyroidism)