Malabsorbtion vs Restriction Post RNY Bypass
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Transcript of Malabsorbtion vs Restriction Post RNY Bypass
The contribution of malabsorption to the reduction in net energy
absorption after long-limb Roux-en-Y gastric bypass
What is Roux-en-Y Gastric Bypass Surgery?
• Roux-en-Y Gastric Bypass (RYGB) combines both
• Restrictive and • Malabsorptive • Components
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• Roux-en-Y gastric bypass (RYGB) restricts food intake, and
• when the Roux limb is elongated to 150 cm, the procedure is believed to induce malabsorption
• Objective measure reduction calories after RYGB
• Restriction of food intake 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. 4 704-713
The contribution of malabsorption to the reduction in net energy
absorption after long-limb Roux-en-Y gastric bypass
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 FordtranAm J Clin Nutr October 2010 vol. 92 no. 4 704-713
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• No statistically significant effects of RYGB on
• Protein or
• Carbohydrate absorption coefficients
• 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
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• 5 months after bypass, • Malabsorption reduced absorption of
combustible energy by 124 ± 57 kcal/d, whereas
• Restriction of food intake reduced energy absorption by 2062 ± 271 kcal/d
• In RNY 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
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• 14 months after bypass, • Malabsorption reduced absorption of
combustible energy by 172 ± 60 kcal/d, whereas
• Restriction of food intake reduced energy absorption by 1418 ± 171 kcal/d
• Restriction 8 times as important as Restriction
• (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
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• On average, malabsorption accounted for 6% and 11% of the total reduction in ccaloric intake at 5 and 14 mo, respectively, after 150 RNY gastric bypass
• RNY: Primarily a Restrictive Procedure
• NOTE: Early signs of 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
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
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
Correlation between the length of jejunum in the biliopancreatic (BP) limb and the reduction in coefficient of fat absorption at 5 (A) and 14 (B) mo after long-limb Roux-
en-Y gastric bypass (RYGB).
The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass
• RNY does not cause bile acid malabsorption
• Fecal bile acid excretion averaged • Before: 0.78 ± 0.08 g/d, • 5 mo: 0.50 ± 0.13 g/d, and • 14 mo: 0.68 ± 0.12 g/d • Decreased Bile Acids Rx Diabetes
Post Gastrectomy Steatorrhea
• Several authors have noted that • Fat malabsorption • More common and to a 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
Steatorrhoea following Gastric Operations:
• Rare after gastro-jejunostomy or vagotomy alone.
• Rare after Billroth I• Common after Polya gastrectomy. • The addition of vagotomy to gastrectomy or
gastrojejunostomy increased the fat• content of the stools.• (Butler, 1961)
Factors implicated as the cause of increased Body fat loss following gastrectomy & Billroth II
• Decreased caloric intake• Gastrointestinal motility
changes • Reservoir function are
responsible for the steatorrhea.
Factors implicated as the cause of increased fat loss following partial gastrectomy & Billroth II
• In a clinical study, Saxon and Ziese stated that
• Loss of the reservoir function of the stomach was of primary cause.
• Loss of body weight correlated significantly with the
• amount of stomach removed at operation and with no other factors.
Factors implicated as the cause of increased fat loss following partial gastrectomy & Billroth II
• Waddell and Wang Abnormal motility rather than lack of reservoir function was the basic physiologic disturbance involved.
• Glazebrook and Welbourn 6 indicted intestinal hypermotility as the cause
Fat absorption and the Billroth II Afferent loop
• An experiment was designed first, to determine whether progressive increase in the length of the afferent loop was predictably associated with increasing fat malabsorption
• Animals underwent a 50% distal gastrectomy with an antecolic
• Polya-type Billroth II anastomosis
Polya Type Gastro-Jejunostomy
Fat absorption and the Billroth II Afferent loop
• Animals underwent a 50% distal gastrectomy with an antecolic
• Polya-type Billroth II anastomosis
• Afferent loops of
• 30, 60, and 90 cm.
Fat absorption and the Billroth II Afferent loop
• Average fecal excretion on a 127 Gm. diet was 2.4% of the ingested fat.
• Similar to results both in dogs and in humans
• Animals with 30 cm. afferent loops
• Able to digest and absorb the fat diet without any apparent difficulty
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. loop fecal fat 2.4% (No Change)• 60 cm. loop fecal fat excretion 10.2%• 90 cm. loop 28.2%
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. loop fecal fat 2.4% (No Change)• 60 cm. loop fecal fat excretion 10.2%• 90 cm. loop 28.2%
Fat MAL-absorption and the Billroth II Afferent loop
• Afferent loop can be a most important factor in the cause of post gastrectomy steatorrhea, depending upon the LENGTH of its construction.
• Animals with short afferent loops did not demonstrate any significant steatorrhea.
• As the length of the afferent loop increased, a concomitant and dramatic rise in fecal fat excretion was noted.
Fat MAL-absorption and the Billroth II Afferent loop
• The malabsorption is probably not due to bypass of the upper jejunum
• Kremen’s demonstration in dogs that
• Over half the jejunum can be bypassed without producing steatorrhea.
• 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
Kremen, et al.
• Experimental studies in dogs reveal that animals also can, with reasonable assurance,
• be deprived of from 50 to 70 per cent of their small intestine and maintain a near normal nutritional status.
Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine
• Study showed that after sacrifice of major lengths of the proximal small intestine,
• the animal's weight is satisfactorily maintained near preoperative levels, and
• no great interference with fat absorption is observed.
Experimental Evaluation of the Nutritional Importance of Proximal and Distal Small Intestine
• 50- 70% of the mesenteric small bowel bypassed
• The bypassed bowel had its blood supply preserved and
• proximal and distal ends were exteriorized as a cutaneous stoma.
• Intestinal continuity was re-established by end-to-end anastomosis
50% of Jejunum Bypassed
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!
70% Bowel Bypassed
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
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.
Transit Time & Fat Absorption
• 50-70% Bypass
• Made Little Difference in Transit Time
• Fat Absorption NOT affected
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
Absorption studies after gastrojejunostomy with and without vagotomy
• It is concluded that serious malabsorption does not follow either gastrojejunostomy or vagotomy
• but may occur quite often when these procedures are combined.
• It seems that the addition of vagotomy to the G-J is responsible for steatorrhea.
• Presumably vagotomy interferes with the gastric, intestine, or biliary response to food.