RNY = Minimal Fat Malabsorption vs MGB = Major Fat Malabsorption

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RNY = Minimal Fat Malabsorption vs MGB = Major Fat Malabsorption

RNY = Minimal Fat Malabsorption vs MGB = Major Fat Malabsorption

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  • 1. Malabsorption following the Roux-en-Y gastric bypass
  • 2. What is Roux-en-Y Gastric Bypass? • Roux-en-Y Gastric Bypass both (?) • Restrictive • Malabsorptive (?) Components
  • 3. Malabsorption vs. Restriction after long-limb RNY gastric bypass • Roux-en-Y gastric bypass (RNY) restricts food intake • when the Roux limb is elongated to 150 cm • IS the RNY malabsorptive? • Measure calorie reduction after RNY • Restriction vs Malabsorption • The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-7
  • 4. “The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass” Elizabeth A Odstrcil, Juan G Martinez, Carol A Santa Ana, Beiqi Xue, Reva E Schneider, Karen J Steffer, Jack L Porter, John Asplin, Joseph A Kuhn, and John S Fordtran Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 5. The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass • Results: • RNY: • No significant effect on • Protein or Carbohydrate absorption • “The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass”, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 6. RNY Malabsorption vs. Restriction • 5 months after bypass, • Malabsorption reduced absorption by 124 kcal/d • Restriction of food intake reduced energy absorption by 2,062 kcal/d • Restriction 16 times more important than Malabsorption • The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 7. RNY Malabsorption vs. Restriction • 14 months after bypass, • Malabsorption reduced absorption of combustible energy by 172 kcal/d • vs • Restriction of food intake reduced energy absorption by 1,418 kcal/d • (Why: Restriction Beginning to Fail) • The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 8. Failure of RNY Caloric Effect
  • 9. RNY Malabsorption vs. Restriction • Malabsorption ONLY 6%-11% reduction in calories • RNY: Is Primarily a “Restrictive Procedure” • Study Shows: Early signs of RNY caloric failure • The contribution of malabsorption to the reduction in net energy absorption after long- limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 10. The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass • Dietary intake and net intestinal absorption of fat, protein, and carbohydrate were measured • Calculated the total reduction in fat, protein, carbohydrate, and calories after RYGB • Extent to which these reductions were due to restriction or malabsorption • The contribution of malabsorption to the reduction in net energy absorption after long- limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 11. The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass • Fat absorption and malabsorption • Average fat intake was • 156 g/d before bypass, • 50 g/d 5 mo after bypass, and • 82 g/d 14 mo after bypass. • The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass, Elizabeth A Odstrcil, et al. Am J Clin Nutr October 2010 vol. 92 no. 4 704-713
  • 12. Correlation between the length of jejunum in the biliopancreatic (BP) limb and the reduction in fat absorption
  • 13. Bile Acid Depletion: Fat Malabsorption & Treatment of Diabetes Most Bariatric surgeons DO NOT Understand Bile/Bile Acids
  • 14. Bile Acids: Not Just for Fat Absorption • Bile Acids Needed for Fat absorption (Decreased Bile Acids => Decreased Fat Absorption) • Studies show that bile acids also play a large role in glucose homeostasis
  • 15. Bile Acids: Not Just Detergents Bile Acids as Hormones • Bile acids as hormones act on several Critical receptors: • Farnesoid X receptor (FXR) and • Pregnane X receptor (PXR), • Constitutive androstane receptor (CAR), • G-protein-coupled receptor TGR5. • Bile acids AS HORMONES regulate Cholesterol, Glucose, and metabolism/energy homeostasis
  • 16. What Most Bariatric Surgeons Do Not Understand • Bile Acids Critical to Fat and Glucose Control in the Body • Decreased Bile Acids => Decreased Fat absorption Lowered Blood Glucose Levels • MGB (Billroth II) => Decreased Bile Acids • RNY does NOT Affect Bile Acid Pool
  • 17. Study of long-limb Roux-en-Y gastric bypass • Results: RNY does not cause bile acid malabsorption • Fecal bile acid excretion average • Before: 0.8 g/d • Post Op 5 mo: 0.5 g/d • Post Op 14 mo: 0.7 g/d • Decreased Bile Acids Rx Diabetes • RNY Does Not Cause Loss of Bile
  • 18. Bile Acid Sequestration Reduces Glucose Levels by Increasing Metabolic Clearance • Bile acid sequestrants (BAS) reduce plasma glucose levels in type II diabetics • BAS induced plasma glucose lowering by increasing metabolic clearance rate of glucose in peripheral tissues • RNY Does Not Cause Loss of Bile • MGB Does Cause Bile Acid Losses
  • 19. Bariatric Surgeons Forget History of GI Surgery What have we learned from 100 years of GI Surgery?
  • 20. Post Gastrectomy Steatorrhea • For over 75 years authors have noted that • Fat Malabsorption/Steatorrhea common post gastrectomy syndrome in some patients • More common & Greater degree with • Billroth II >> Billroth I • EVERSON TC. Experimental comparison of protein and fat assimilation after Billroth II, Billroth I, and segmental types of subtotal gastrectomy. Surgery. 1954 Sep;36(3):525-37 • MACLEAN LD, PERRY JF, KELLY WD, MOSSER DG, MANNICK A, WANGENSTEEN OH. Nutrition following subtotal gastrectomy of four types (Billroth I and II, segmental, and tubular resections). Surgery. 1954 May;35(5):705-18 • WOLLAEGER EE, WAUGH JM, POWER MH. Fat-assimilating capacity of the gastrointestinal tract after partial gastrectomy with gastroduodenostomy (Billroth I anastomosis). Gastroenterology. 1963 Jan;44:25-32 • …
  • 21. 100 Years of GI Surgery: Steatorrhea following Gastric Operations: • What do we know: • Rare after gastro-jejunostomy or vagotomy alone. • Rare after Billroth I • Especially Common after Polya gastrectomy with BII. • (Butler, 1961)
  • 22. Polya Type Gastro-Jejunostomy NOTE: Large Wide Open Gastro- jejunostomy
  • 23. Opinion Among BPD Surgeons • Length of the Common Channel is the Critical Factor for Fat malabsorption & weight loss • We review Animal studies and MGB results that suggest this is not the case • Am J Surg. 2005 May;189(5):536-40, Common channel length predicts outcomes of biliopancreatic diversion alone and with the duodenal switch surgery, McConnell DB, O'rourke RW, Deveney CW
  • 24. NUTRIENT ABSORPTION in the SMALL INTESTINE: Remember the Basics • Duodenum and Upper Jejunum: most minerals • Jejunum and Upper Ileum: carbohydrates, amino acids, water-soluble vitamins • Jejunum: absorbs most of lipids and fat-soluble vitamins • Terminal Ileum: Bile,Vit B12
  • 25. Fat absorption and the Length of Billroth II Afferent Limb • Experiment • Question: Increase length of afferent limb associated with increased fat malabsorption • Animals underwent a 50% distal gastrectomy with an antecolic • Polya-type Billroth II anastomosis
  • 26. Fat absorption and the Billroth II Afferent loop • 50% distal gastrectomy with an antecolic • Polya-type Billroth II anastomosis • Afferent limb of • 30cm, 60cm, 90cm
  • 27. Fat absorption and the Billroth II Afferent Limb: RESULTS • PreOp: Fecal excretion on a 127 Gm. diet 2.4% of the ingested fat. • Similar results in dogs and in humans • Animals with BII + 30cm afferent limbs • Able to digest and absorb the dietary fat without any apparent difficulty
  • 28. Fat absorption and the Billroth II Afferent loop • Average fecal excretion diet was 2.4% of the ingested fat. • Longer Loops steatorrhea increased • 30 cm. limb fecal fat 2.4% (No Change) • 60 cm. limb fecal fat excretion 10.2% • 90 cm. limb 28.2%
  • 29. Fat Malabsorption Billroth II (MGB) vs RNY 0 5 10 15 20 25 30 0 20 40 60 80 100 Bypass Limb Length FatLost(%) MGB Billroth II RNY
  • 30. Fat absorption and the Billroth II Afferent loop • Average fecal excretion Pre Op 2.4% of ingested fat • Longer Limb increased steatorrhea • 30 cm. limb fecal fat 2.4% (No Change) • 60 cm. limb fecal fat excretion 10.2% • 90 cm. limb 28.2%
  • 31. Fat MAL-absorption and the Billroth II Afferent LIMB • Afferent limb most important factor post gastrectomy steatorrhea, “LENGTH” • Animals with short afferent loops NO significant steatorrhea. • As the length of the afferent limb increased, a concomitant and dramatic rise in fecal fat excretion was noted.
  • 32. Fat MAL-absorption and the Billroth II Afferent loop • Malabsorption is NOT due to bypass of the upper jejunum ALONE • Kremen’s Study: • Over half the jejunum can be bypassed without producing steatorrhea.
  • 33. An Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine • Arnold J. Kremen, et al. Ann Surg. 1954 September; 140(3): 439–447
  • 34. Kremen, et al. • “Experimental studies in dogs reveal that animals can bypass • 50 to 70 per cent of their small intestine • and maintain a near normal nutritional status”
  • 35. Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine • Study showed that • Bypass of major lengths of the proximal small intestine, • Weight is well maintained • No great interference with fat absorption • NOTE: Contradiction with Prior Study
  • 36. Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine • 50 - 70% of the small bowel bypassed • Proximal and distal ends were exteriorized as a cutaneous stoma. • Intestinal continuity was re- established by end-to-end anastomosis
  • 37. 50% of Jejunum Bypassed: No Weight Loss!
  • 38. Massive bypass = No Effect • The small intestine in adults is a long and narrow tube about 7 meters (23 feet) long • 50% Bypass = 11.5 ft (3.5 meters) • Minimal Weight Loss!
  • 39. 70% Bowel Bypassed Minimal Weight Loss
  • 40. Massive bypass = Little Effects! • The small intestine in adults is a long and narrow tube about 7 meters (23 feet) long • 70% Bypass = 16 ft (5 meters) • 5% weight loss
  • 41. 70% Bypass = Little Effect • Group IV animals, which were similar to Group I except that 70% instead of 50% of proximal small bowel removed from intestinal continuity, • Lost about five per cent of their preoperative weight and then stabilized at this level.
  • 42. Transit Time & Fat Absorption • 50-70% Bypass • Made Little Difference in • Transit Time or • Fat Absorption NOT affected
  • 43. Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine • CONCLUSIONS • The proximal 50 to 70 per cent of the small intestine can be removed with no apparent ill effects. • Weight is maintained, and protein and fat absorption are not significantly altered. • Arnold J. Kremen, John H. Linner, and Charles H. Nelson
  • 44. Bypass of Jejunum; Experimental Results: No Fat Malbsorption or Major Fat Malabsorption • 2 Studies; 2 Different Findings • Massive Small Bowel Bypass => Minimal Effects • Moderate Small Bowel Bypass =>Major Effects • What is the Difference?
  • 45. It’s the Billroth II
  • 46. Billroth II + Moderate Bypass = Fat Malabsorption and Good Weight Loss
  • 47. RNY • Primarily Restrictive • Minor fat malabsorption • No Malabsorption of Protein or Carbohydrate • Restriction begins to fade early