Overview
Definition:
Roux-en-Y gastric bypass (RYGB) is a bariatric surgical procedure that involves creating a small gastric pouch and connecting it directly to the jejunum, bypassing a significant portion of the stomach and duodenum
It is considered the gold standard for weight loss surgery due to its efficacy in inducing substantial and sustained weight loss and improving obesity-related comorbidities.
Epidemiology:
Obesity affects over 2 billion people worldwide
Bariatric surgery, including RYGB, is performed on hundreds of thousands annually
Patient demographics typically include adults with a BMI of ≥40 kg/m², or BMI of ≥35 kg/m² with significant comorbidities like type 2 diabetes, hypertension, or obstructive sleep apnea.
Clinical Significance:
RYGB offers significant improvements in obesity-related comorbidities, including type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea, and osteoarthritis
It is associated with substantial weight loss and improved quality of life, making it a crucial procedure for managing severe obesity and its sequelae.
Indications
Absolute Indications:
BMI ≥ 40 kg/m²
BMI ≥ 35 kg/m² with at least one obesity-related comorbidity (e.g., type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea, non-alcoholic fatty liver disease, osteoarthritis)
Failure of adequate non-surgical weight loss interventions.
Relative Indications:
BMI between 30-34.9 kg/m² with severe obesity-related comorbidities that are poorly controlled
Certain metabolic disorders and infertility associated with obesity.
Contraindications:
Uncorrected coagulopathy
Severe cardiopulmonary disease precluding surgery
Active peptic ulcer disease
Inflammatory bowel disease
Alcohol or drug abuse
Inability to comply with postoperative follow-up
Pregnancy
Major psychiatric illness that is uncontrolled.
Preoperative Preparation
Patient Assessment:
Comprehensive medical evaluation including history, physical examination, and baseline laboratory tests (CBC, electrolytes, renal and liver function tests, lipid profile, HbA1c)
Nutritional assessment by a dietitian
Cardiac and pulmonary evaluation if indicated
Psychiatric evaluation to assess readiness and compliance.
Nutritional Counseling:
Education on dietary changes required before and after surgery
Emphasis on protein intake, hydration, and avoidance of high-calorie, low-nutrient foods
Recommendations for vitamin and mineral supplementation will be initiated preoperatively.
Medication Management:
Review and adjustment of medications, particularly those for diabetes and hypertension
Discontinuation of certain medications like NSAIDs and anticoagulants prior to surgery as per protocol
Prophylactic antibiotics will be administered prior to incision.
Patient Education:
Detailed explanation of the surgical procedure, potential risks, benefits, and expected outcomes
Discussion of the lifelong commitment to dietary changes, exercise, and regular follow-up appointments
Addressing patient concerns and answering questions.
Procedure Steps
Gastric Pouch Creation:
The stomach is divided, creating a small (approximately 15-30 mL) gastric pouch by stapling or division using a gastrointestinal anastomosis (GIA) stapler
This pouch is isolated from the remainder of the stomach, which is bypassed.
Biliopancreatic Limb Division:
The jejunum is divided approximately 40-50 cm distal to the duodenojejunal flexure
The distal end of the jejunum (alimentary limb) is brought up to the gastric pouch.
Gastrojejunostomy Formation:
A gastrojejunostomy is created between the gastric pouch and the afferent limb of the divided jejunum, typically using a circular stapler or hand-sewn technique
This anastomosis is usually placed lower down in the jejunum.
Roux Limb Anastomosis:
The proximal end of the divided jejunum (biliopancreatic limb) is anastomosed to the distal jejunum (alimentary limb) approximately 100-150 cm distal to the gastrojejunostomy, forming the Roux limb
This ensures the flow of bile and pancreatic enzymes to the digestive tract.
Anastomotic Leak Testing:
The integrity of the gastrojejunostomy and jejunojejunostomy is typically tested intraoperatively using methylene blue or saline solution to detect any leaks before closing the abdomen.
Postoperative Care
Early Management:
Intensive monitoring in the recovery room
Pain management with IV analgesics
Close monitoring of vital signs, fluid balance, and urine output
Nasogastric tube (NGT) management for gastric decompression if necessary.
Dietary Progression:
Starts with clear liquids for 2-3 days, progressing to full liquids, then pureed foods, soft foods, and finally regular diet over several weeks
Emphasis on small, frequent meals and slow eating
Avoidance of sugary drinks and high-fat foods.
Fluid And Electrolyte Balance:
Intravenous fluids are continued until adequate oral intake is established
Monitoring of electrolytes, especially potassium, sodium, and magnesium, is critical
Prompt correction of any imbalances.
Mobilization And Thromboprophylaxis:
Early ambulation is encouraged to prevent deep vein thrombosis (DVT) and pulmonary embolism (PE)
Mechanical compression devices and/or low-molecular-weight heparin (LMWH) are used for thromboprophylaxis.
Complications
Early Complications:
Anastomotic leaks (gastrojejunostomy or jejunojejunostomy) leading to peritonitis and sepsis
Bleeding from staple lines or surgical sites
Bowel obstruction due to adhesions or internal hernias
Pulmonary complications such as pneumonia or atelectasis
Wound infections
DVT/PE.
Late Complications:
Nutritional deficiencies (iron, B12, calcium, vitamin D, folate, thiamine) leading to anemia, osteoporosis, and neurological deficits
Dumping syndrome (early and late) characterized by gastrointestinal distress and vasomotor symptoms
Marginal ulcers at the gastrojejunostomy
Internal hernias and small bowel obstruction
Gallstones
Weight regain
Strictures or stenosis at the gastrojejunostomy.
Prevention Strategies:
Meticulous surgical technique with careful leak testing
Adequate nutritional supplementation with lifelong adherence to vitamins and minerals
Patient education on dietary modifications
Regular postoperative follow-up to monitor for nutritional deficiencies and complications
Early recognition and management of internal hernias.
Key Points
Exam Focus:
Understand the anatomical changes in RYGB
Recognize the indications and contraindications for the procedure
Differentiate between early and late complications
Know the management of nutritional deficiencies and dumping syndrome.
Clinical Pearls:
Emphasize lifelong vitamin and mineral supplementation
Counsel patients on behavioral changes required for sustained weight loss
Recognize the signs and symptoms of internal hernias, which require urgent surgical evaluation
Monitor for anemia and B12 deficiency closely.
Common Mistakes:
Inadequate nutritional counseling and follow-up
Failure to recognize and manage nutritional deficiencies promptly
Misdiagnosis or delayed diagnosis of internal hernias
Overlooking marginal ulcers as a cause of abdominal pain and vomiting.