bariatric surgery

Question 1

Eligibility for bariatric surgery

Answer 1

1. BMI >35

2. Type II diabetes or other complications of co-morbidities

Question 2

Restrictive surgeries (3)

Answer 2

1. Vertical banded gastroplasty
2. Sleeve gastroectomy
3. Laparoscopic adjustable gastric banding (lap band)

Question 3

Laparoscopic adjustable gastric banding

Answer 3

1. Close off the top of the stomach so that only a 1-2oz pouch is left
2. Wrap stomach and control sizing with aperture

Limitations

1. Continue eating; stretch stomach
2. food can’t get into gastric pouch, in esophagus –> vomit

Question 4

Malabsorptive surgeries (2)

Answer 4

1. Duodenal switch/ biliopancreatic diversion
2. Dudoenal sleeve

Limitations

1. Non-absorbed fat calories: steatorrhea
2. Carbs broken down by microbes in colon: methane gas –> flatulence

Question 5

Combined surgery

Answer 5

Roux-en-y gastric bypass
-most common malabsorption surgery

1. Connect top of stomach straight to distal ileum
2. Bypass large portion of stomach and small intestine
3. Malabsorption of vitamins: iron, B12, Vit D
4. Dumping risk
5. Massive 100 fold increase in GLP1 and GIP secretion –> improves insulin sensitivity and decreases glucagon secretion

Question 6

Duodenal switch/biliopancreatic diversion

Answer 6

1. Disconnect duodenum and plug in to ileum
2. Carb and fat malabsorption
3. No fat soluble vitamins absorption

Question 7

Laparoscopic sleeve gastrectomy (restrictive)

Answer 7

1. Wrap stomach (bypass)
2. Leaves proximal small intestine unaffected
3. Weight loss, some dumping
4. Problems with nausea and vomiting

Question 8

Scandinavian Obesity Study

Answer 8

1. Cohort, not randomized
2. Longest study on bariatric surgery
3. Graphs were misleading: 20-30% decrease in weight. However # of patients decreases significantly over the years
4. Decrease in TAG, LDL, cholesterol, diabetes, hypertension, hyperuricemia = only 2/3 of population
5. Fails to show follow-ups or complications

Question 9

Mechanisms of improving glycemic parameters (8)

Answer 9

1. weight lost (starving)
2. increase in insulin response (prob due to GLP1)
3. Improved GI hormonal response (GLP1, incretins)
4. decrease insulin resistance (hepatic level-neuronal modulation)
5. increase in plasma adiponectin
6. decrease in ghrelin
7. decrease in inflammatory agents

Question 10

Short term metabolic changes (5)

Answer 10

1. Metabollically starve patient (NPO for 3-4days)
2. Starvation state: mobilize fat and increase ketone bodies
3. Less calories absorbed, less insulin secreted –> decrease in insulin resistance
4. Decrease in leptin –> deficient
5. Increase in adiponectin (visceral and subcutaneous adipocytes derease)

Question 11

Long-term: hypoglycemia(3)

&

Management (4)

Answer 11

1. Seen 2-3 years after procedure, post-prandial
2. Leads to loss of consciousness, seizures, nesidioblastosis (hyperplasia of beta cells)
3. Requires surgery to fix

Management

1. Avoid high sugar foods
2. consume frequent, small meals
3. Limit fluid intake to prevent dumping
4. eat a lot of protein, fiber, and modest increase in dietary fat

Question 12

Malabsorption => Malnutrition (4)

Answer 12

1. GBP= Iron, B12, Vit D, Ca metabolism
2. D/S-protein, fat soluble vit, Ca metabolism
3. AGB-folate, telopeptide marker changes
4. Sleeve-iron, B12, vit D

1-3: thiamin also (vomiting)

Question 13

Long-term management post surgery (5)

Answer 13

1. Treat weight regain with dietary counseling, physical activity, behavior modification, and sometimes drug therapy
2. Ensure adequate protein eaten
3. Measure PTH to evaluate Vit D and Ca levels
4. Keep hydrated (major cause of readmission)
5. Supplements: iron, B vitamins, Calcium