Understanding Weight Loss After Bariatric SurgeryUnderstanding the Bilio-Pancreatic Limb Length Statistics, Random Distribution and Too Little or Too Much of a Good Thing

1. First: Patients Do Not Experience
MEAN Weight Loss!
• Many surgeons use the MEAN (Average)
to Judge the result
(i.e. Mean %Excess Weight Loss)
• While the MEAN is useful...
• It is like
looking at only one end of the Elephant
• And Sometimes it is the WRONG End

2. Understanding Weight Loss After
Bariatric Surgery
Understanding the
Bilio-Pancreatic Limb Length
Statistics, Random Distribution and
Too Little or Too Much of a Good
Thing

3. To Tailor or Not to Tailor
Most Important to UNDERSTAND: BP Limb Length and Outcomes
1. BP Limb Length “Roughly” Predicts Wt Loss (Rutledge)
2. Simple: More BP Limb => More Weight Loss
3. More Weight Loss =>
Increase Risk of Excessive Weight Loss (i.e. BPD SADI etc...)
4. MGB gives Choice (Patient & Surgeon)
5. OK, Don't Tailor => Less Wt Loss & Lower Risk Malnutrition
6. In Skilled Hands: Excellent Wt Loss & Low Risk of Excessive Wt Loss
MGB in others => Can be Dangerous & Deadly
7. Surgeon MUST understand Easy Rapid Rx excessive Wt Loss
8. NEED: Standardization, Education & Recognition

4. Topics & Objectives
1. MGB is an Excellent Procedure: Look at the Data
2. MGB: Widespread, Persistent Confusion (examples)
i.e. BP Limb Length Does Not Predict Weight Loss (Wrong)
i.e. Fear of MGB Malnutrition (MGB rates similar to RNY)
i.e. Mismanagement of MGB Malnutrition
(Don't Do Weight Loss Surgery for Malnurition)
3. Need MGB Standardization, Education, Recognition of
MGB Surgeons of Excellence

5. Confusion By Surgeons
Who Do Not Understand the MGB
?? MGB Best Bariatric Surgery ??
In Hundreds of Articles of MGB
In Every Study, By Every Measure
the MGB is Equal to or
(More Often) Better Than
Any Comparable Bariatric Surgery
(Including Randomized Controlled
Prospective Trials)

6. Understanding the Obvious
• First: If you do not understand an operation (MGB)
• Do Not Use the Operation!!
• In Short: This Presentation in Summary:
1. Widespread and Persistent Misunderstanding of MGB
2. Often Leading to Complications and Even Death
3. Needed: * Standardization of MGB, ** Education and
*** Recognition of Knowledgeable and Skilled Surgeons

7. Needed: Standardization of MGB
and Recognition of Surgeons
Knowledgeable and Skilled in its
use
* Standardize, ** Educate, *** Recognize
The Best in MGB
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Board of Governors of the MGB Review Corp
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Facebook Messenger: @DrRRutledge,
Phone: 702-483-7133 or 702-714-0011 or What's App: Dr Rutledge

9. Confusion By Surgeons Who Do Not
Understand the MGB
How Often
Have Surgeons
And
Continue to Be Wrong
About the Mini-Gastric Bypass?

10. Confusion By Surgeons Who Do Not
Understand the MGB
Some Examples of MGB Confusion
1. The Pouch is Too Big & Pts Will Not Loose Weight
2. Short Gastric Pouch (MGB = Old Mason Loop)
3. Dissection EG Junction and crural Repair
4. MGB with a “Ring”
5. Irrational Fear of Bile Reflux
6. Confused About Risk Gastric Cancer
7. Fear of Malnutrition
8. Management of MGB Complications
And More...

11. Bowel Bypass Limb Length &
Weight Loss
• Recently the confusion about
Bowel Bypass Limb Length and
Weight Loss
• Many Studies of RNY => No advantage of BP Limb
length Re: Weight Loss
• Surgeon Advocate MGB 150 cm bypass only.
Why?
150 cm => Less Malnutrition (Correct)
150 cm => Equal Weight Loss (Wrong)

12. Summary (In Short)
1. BP Limb/Weight Loss, 2. Malnutrition & MGB, 3. Rx Excessive Wt Loss
1. BP Limb and Weight Loss
(Hint: Longer Bypass = More Weight Loss)
2. Malnutrition and MGB
(Hint: Uncommon and Easily Managed and
MGB Unique: Surgeon/Patient can choose
More Power or Lower Risk of Excess Wt Loss)
3. Management of Excess Weight Loss after MGB
(Hint: Easy, immediate 30-60 minute revision
NOT RNY!)

13. To Tailor or Not to Tailor
Most Important to UNDERSTAND: BP Limb Length and Outcomes
1. BP Limb Length “Roughly” Predicts Wt Loss (Rutledge)
2. Simple: More BP Limb => More Weight Loss
3. More Weight Loss =>
Increase Risk of Excessive Weight Loss (i.e. BPD SADI etc...)
4. MGB gives Choice (Patient & Surgeon)
5. OK, Don't Tailor => Less Wt Loss & Lower Risk Malnutrition
6. In Skilled Hands: Excellent Wt Loss & Low Risk of Excessive Wt Loss
MGB in others => Can be Dangerous & Deadly
7. Surgeon MUST understand Easy Rapid Rx excessive Wt Loss
8. NEED: Standardization, Education & Recognition

14. 1. BP Limb and Weight Loss
(Hint: Longer Bypass =
More Weight Loss)

15. Dr Rutledge's Study
BP Limb Length & Weight Loss
4,000+ patients
Longer bypass => More Weight Loss

16. Linear Regression Line (R2=0.39)

19. BP Limb & Weight Loss: Conclusions
• Largest reported study of bypass length and weight loss after gastric bypass.
• Prior negative studies with small sample sizes may have suffered from a Type II
error.
• (Small sample => No Diff)
• Preop weight & limb length significantly associated w weight loss
• Every additional foot of bowel bypassed is associated with a
mean increase in the expected one year weight loss.

21. Dr Rutledge's Study
BP Limb Length & Weight Loss
Very Simple Conclusions
1. Longer bypass = More Weight Loss
2. Longer bypass = More Power (Mean XsWL)
3. More Power => Increased Risk of Excess Weight Loss (Small)

22. 2. Malnutrition and MGB
(Hint: Uncommon and Easily Managed
and
MGB Unique: Surgeon/Patient can
Choose
More Power or Lower Risk of
Excess Wt Loss)

23. Confusion By Surgeons Who Do Not
Understand the MGB
Fear of Malnutrition
Management of MGB
Complications
Focus

24. Recently Surgeons Have
“Discovered” Malnutrition after the MGB!
1. Impact of biliopancreatic limb length on severe
protein‒calorie malnutrition requiring revision Mahawar K
J Minim Access Surg. 2017
2. Severe fatal protein malnutrition after mini-gastric bypass
surgery: Case report Motamedi M., Int J Surg Case Rep.
2017
3. Laparoscopic reversal of mini-gastric bypass to original
anatomy for severe postoperative malnutrition. Genser L
Langenbecks Arch Surg. 2017
4. Laparoscopic conversion mini-gastric bypass to proximal
RnY for malnutrition: case report Rosenthal R Surg Obes
Relat Dis. 2009

25. Recently Surgeons Have
“Discovered” Fear Malnutrition after the MGB!
1. Shows Evidence of Deep Misunderstanding of:
2. Of the MGB (Uncommon & Easily Managed)
3. Of the RNY (Has Similar Risk of Malnutrition)
4. Of the SADI BPD etc (MUCH Worse malnutrition)
5. But MOST Important;
Misunderstanding of Simple Statistics
(Mean & Std. Deviation, Simple)

26. Fear of Malnutrition in the MGB
One Example:
• 12 pts TPN nutrition
• 7 "one-anastomosis gastric bypass" (OAGB)
or "mini gastric bypass,"
“This case series suggests that OAGB
could over expose subjects to severe
nutrition complications”
JPEN J Parenter Enteral Nutr. 2017 Need for Intensive Nutrition Care
After Bariatric Surgery. Bétry C

27. Fear of MGB
Malnutrition
Shows Ignorance of Large Scale
MGB Series Studies

28. Evidence of Deep Misunderstanding of the MGB
•What Do large Scale Series of MGB Report?
Two Examples
•All Large Scale MGB Series are the Same:
•Malnutrition after MGB:
Risk LOW & Treatment Easy **
• (** If Surgeon Knows What to Do **)

29. Malnutrition Post MGB
Deep Misunderstanding of MGB
• Obes Surg. 2016
Laparoscopic Conversion of (Mini) Gastric Bypass
Complications
• 49 Conversions of 2,382 Cases
= 2%
• 58% Conversions for Malnutrition
= 1% MGB => Revision for Malnutrition

30. Malnutrition Post MGB
Deep Misunderstanding of MGB
• Surg Obes Relat Dis. 2015
Mini-gastric bypass: long-term results,
Chevallier J M
• Malnutrition Required Revision
= 1.6%

31. Fear of Malnutrition?
MGB Malnutrition Rate: 4 / 1,000 MGBs
• MGB Malnutrition requiring revision
• Total survey data
• 101 Surgeons (Many NOT Doing Standard MGB)
• 36,952 Patients
• *Malnutrition Rate 0.4%* (138 pts)
• Severe protein‒calorie malnutrition requiring revisional surgery
after one anastomosis (mini) gastric bypass, Mahawar J Minim
Access Surg. 2017

32. Fear of Malnutrition?
MGB Malnutrition Rate: 4 / 1,000 MGBs
• MGB Malnutrition requiring revision
• 101 Surgeons (Many NOT Doing Standard
MGB),
36,952 Patients, *Malnutrition Rate 0.4%* (138 pts)
• 5-10 Times LOWER Than RNY, 50-100 Times Lower than SADI
• Mahwar 2017

33. Fear of MGB
Malnutrition
Little Recognition of Other Studies
Comparison RNY vs MGB
Risk of Malnutrition

34. RNY vs MGB
Risk of Malnutrition
Evidence of Deep Misunderstanding of
the RNY, Malnutrition, Revision Data
RNY has Malnutrition/Revision Rates
Roughly Equal to MGB

35. Pubmed Searches:
A Simple Test
• PUBMED:
Search “roux-en-y gastric bypass”
=> 11,834 Articles
•Search “Roux-en-y gastric bypass”
+ “Malnutrition”
=> 481 articles
4% of All RNY Articles are on Malnutrition

36. Pubmed Searches:
A Simple Test
•Search “roux-en-y gastric bypass”
=> 11,834 Articles
•Search “Roux-en-y gastric bypass”
+ “Deficiency”
=> 514 articles
4% of All RNY Articles are on Deficiency

37. RNY Malnutrition
Sample Articles (There are > 400 More...)
1. Revisional surgery for severe protein-calorie malnutrition after Roux-en-Y gastric
bypass: Ceneviva R, Surg Obes Relat Dis. 2016
2. Endoscopic reversal of gastric bypass for severe malnutrition after Roux-en-Y
gastric bypass surgery. Ngamruengphong S, Gastrointest Endosc. 2015
3. Risk of Malnutrition, Trace Metal, and Vitamin Deficiency Post Roux-en-Y Gastric
Bypass, Billeter A, Obes Surg. 2015
4. Malnutrition-induced myopathy following Roux-en-Y gastric bypass. Hsia A, Muscle
Nerve. 2001
+ 400 more...

38. RNY Malnutrition
Requiring “Feeding Tube”
• 3,487 pts
•
139 (3.9%) required a *Feeding Tube*
• Refractory malnutrition was the indication after RnY bypass
• Department of Surgery, University of Virginia Health System,
Charlottesville, Virginia
• Surg Obes Relat Dis. 2016 Feeding tube placement for
malnutrition, Charles EJ

39. Malnutrition and RNY
Reversal of Roux-en-Y
• 2017 IFSO President Himpens
• RNY side effects => reversal
•Dumping, hypoglycemia, Malnutrition, severe
diarrhea and excessive nausea and vomiting
• Obes Surg. 2017 Medium-Term Outcomes after Reversal of
Roux-en-Y Gastric Bypass. Arman G, Himpens J

40. Roux-en-Y gastric bypass reversal:
A Systematic Review
• 35 articles
• Malnutrition was the most common
indication for reversal
• Followed by severe dumping syndrome
(9.4%), postprandial hypoglycemia (8.5%),
and excessive weight loss (8.5%)
• Surg Obes Relat Dis. 2016 Roux-en-Y gastric bypass reversal,
Shoar S

41. RNY Most Common Indication for TPN
J Parenter Enteral Nutr. 2017
• 54 pts (6.3%) had TPN post bariatric surgery.
• The most common procedure was
• Roux-en-Y gastric bypass (72%),
• Malnutrition the most common indication (57%).
• Weight at TPN 72 kg
• JPEN J Parenter Enteral Nutr. 2017 Home Parenteral
Nutrition in Bariatric Surgery- Malnutrition. Mundi M

42. Study Sleeve and RNY
Same Decrease in PreAlbumin
• Continuous decrease in prealbumin
•Mild protein depletion
38% of RNY
52% of Sleeve
• “RNY & Sleeve comparable effects in risk of
micro-nutrient and protein deficiencies”
• Obes Surg. 2016 Micro-nutrient and Protein Deficiencies After Gastric
Bypass and Sleeve Gastrectomy

43. Excessive Weight Loss Following Roux-en-Y
Obes Surg. 2016 Management of Excessive Weight Loss Following Roux-
en-Y
• RNY Pts successfully reversed to
normal anatomy after evaluation,
management, and treatment by
multidisciplinary team.
• Lowest BMI (kg/m(2)) was 14.2
• Obes Surg. 2016 Management of Excessive Weight Loss
Following Roux-en-Y Akusoba

44. SADI
Obes Surg. 2017 SADI: A Systematic
Review
1/3
One out of 3 found to have
Malnutrition

45. SADI
A Systematic Review of Efficacy and Safety
• 12 studies including 581 SADI
• %EWL
70% @ 1 year
85% @ 2 years
• Malnutrition in up to
* 34% * of patients
• Obes Surg. 2017 Single Anastomosis Duodeno-Ileal Switch
(SADI): A Systematic Review of Efficacy and Safety.

46. But MOST Important
Evidence of Deep
Misunderstanding of
Simple Statistics
(Mean & Std. Deviation, Simple)

47. Simple Statistics Suggest Risk of
Malnutrition
• RNY/MGB/BPD,SADI
• Est. Mean %XsWtLoss = 72/78/82% (Roughly)
• Standard Deviation: 23/23/24%
• If we assume 120% Excess Weight Loss is
indicative of Malnutrition
• Mean + S.D. => Easy EXPECTED Malnutrition
• Expected Rate from Simple Statistics
for Band/Sleeve/RNY/MGB/BPB,SADI

48. RNY: Risk of Malnutrition/Excess Weight
Loss
1. RNY Mean Excess Wt Loss: = 72% **
(Powerful)
2. Standard Deviation (S.D.) =
23%
3. Malnutrition/eXcessWL (MXWL) = Loss
of 120% XBL
4. RNY: Risk Malnutrition/eXcess WL
(MXWL) =
1.8% (Moderate Risk)

49. MGB (2M bypass): Risk of
Malnutrition/Excess Weight Loss
1. MGB (2M bypass) Mean Excess Wt
Loss: = 78% **
(More Powerful Surgery)
2. Standard Deviation (S.D.) =
24%
3. Malnutrition/eXcessWL (MXWL) = Loss
of 120% XBL
4. MGB (2M bypass): Risk
Malnutrition/eXcess WL (MXWL) = 3%
(Higher Risk)
5. BUT MGB Can Be Tailored!

50. BPD/SADI etc: Risk of Malnutrition/Excess
Weight Loss
1. BPD/SADI etc Mean Excess Wt Loss:
= 82% ** (Very Powerful)
2. Standard Deviation (S.D.) =
24%
3. Malnutrition/eXcessWL (MXWL) =
Loss of 120% XBL
4. BPD/SADI etc: Risk
Malnutrition/eXcess WL (MXWL) =
**6% (Highest Risk)

51. MGB: Unique
Offers the Surgeons Choice:
Choose More Power or Safety
The Surgeon, Family and Patient
Can choose an operation that
matches their situation

52. Simple Example of Expert Use of MGB
BP Limb Titration
•Power: BP Limb Length 200cm =
Excess Weight Loss ~ 1/100 patients
•Conservative: BP Limb Length 150cm =
Excess Weight Loss ~ 1/1,000 patients
•How to Use this Knowledge...

53. Simple Example of Expert Use of MGB
BP Limb Titration
• Patient: 50 y.o diabetic, Glucose 400mg, 400 units
Insulin, Blind in one eye losing site in the other.
Gangrene in two toes, s/p MI time 2, CVA and
recent TIA... Physician predict risk of impending
death!
• Discuss options with the Pt & Family
• Might Choose Greater Power:
BP Limb Length 200cm =
Risk Excess Weight Loss ~ 1/100 patients

54. Simple Example of Expert Use of MGB
BP Limb Titration
• Patient: Young Female BMI 40 possible poor
follow up otherwise good health. + Vegetarian
• Discuss options with the Pt & Family
• Might Choose Conservative:
BP Limb Length 150cm =
Excess Weight Loss ~ 1/1,000 patients

55. •MGB Uniquely Qualified to Allow Patient and
Surgeon to Address Power & Surgery Risk
Modulating Risk of Malnutrition/Excess Weight
Loss
Study Demonstrates Power and Risk of
Malnutrition/Excess Weight Loss
MGB Allows patient and surgeon to titrate
operative choices based upon preferences and
secondarily to easily address post op excess
weight loss or malnutrition

56. MGB Titrate Operative Choices
(1.5 vs 2.0 BP Limb)
• Similar this survey MGB surgeons have reported
on rates of Post Op Malnutrition and excess weight
loss requiring re-operation:
• Results: Risk of Malnutrition/Excess Weight Loss
• MGB BP Limb of 2 meters eXcess WL
requiring revision surgery 1%
• MGB BP Limb of 1.5 meters eXcess WL
requiring revision surgery 0.1%

57. MGB: Patient and Surgeon Choice
MGB with BP Limb of 2 meters for
Maximal weight Loss and approximately
1-3% risk of excess weight loss
Or
MGB with BP Limb of 1.5 meters for Less
weight Loss and approximately 0.1% risk
of excess weight loss

58. Choosing Weight Loss Surgery (RNY) for
Malnutrition/Excess Weight Loss after MGB
17 patients underwent OLGB (MGB) conversion to
RYGB
Almost Half, 41%, developed major Complications
“The conversion of MGB to RNY is associated with
high morbidity”
Opinion: Do not Do Weight Loss Surgery for
Malnutrition/Deficiency After MGB
Surg Obes Relat Dis. 2017 Roux-en-Y gastric bypass for the treatment of severe complications after
omega-loop gastric bypass Poghosyan

59. Management of MGB
Excess Weight Loss
• Immediate Assess Nutritional Status/Resuscitation +
Early Surgical Revision (Do Not Delay)
• Classify Malnutrition/Deficiencies:
90% Severe/Sick:
Rx: Divide GJ + Gastro-gastrostomy (Op Time 30-60 min)
10% Mild:
Rx: Divide GJ + Shorten Bypass (Op Time 30-60 min)
• (Warning: Not RNY! Don't Do Weight Loss Surgery for
Excess Weight Loss/Malnutrition)

60. A More Detailed Explanation
Simple Statistics
Expected Weight Loss
vs
Risk Malnutrition

61. First: Patients Do Not Experience
MEAN Weight Loss!
• Many surgeons use the MEAN (Average)
to Judge the result
(i.e. Mean %Excess Weight Loss)
• While the MEAN is useful...
• It is like
looking at only one end of the Elephant
• And Sometimes it is the WRONG End

62. Problems with the MEAN
Patients
Do Not Lose
a Mean
Amount of
Weight

63. Weight and Metabolic Outcomes 12
Years after *RNY* Gastric Bypass
• The mean unadjusted change from
baseline in body weight in the surgery
group was −46.8 kg
• (95% confidence interval, −48.0 to −45.5)
• 5% of RNY Pts lose > 100 lbs
• NEJM 2017

64. Mean % Weight
Loss
Some Sustained
Massive Weight
Loss
i.e. 300 lb/136 kg pt

65. Understanding Weight Loss
• It is Not Enough to Know the MEAN
weight loss
• You must understand the
SCATTER
• The Standard Deviation (Std. Dev., S.D.)

66. Understanding Weight Loss
1. First Simple Things
2. Then We'll Study Statistics
3. In Short:
Fear of Malnutrition
is Simple Lack of Basic Knowledge

67. 1. First Simple Things

68. Dr Rutledge's Study
BP Limb Length & Weight Loss
• 4,000+ Patient Study
• 1. Longer bypass = More Weight Loss
• 2. Longer bypass = More Power (MeanXsWL)
• 3. More Power = Increased Risk of Excess Weight Loss
• 4. MGB is Unique “Tailored Operation”

69. Dr Rutledge's Study
BP Limb Length & Weight Loss
• 4,000+ patients
• 1. Shorter bypass = Less Weight Loss
• 2. Shorter bypass = Less Power (Mean XsWL)
• 3. Less Power = Decreased Risk of Excess Weight
Loss
• 4. MGB is Unique “Tailored Operation”

70. Conclusions
• More Bypass = More Weight Loss /
Increased Risk of Excess Weight Loss
• MGB is UNIQUE;
Surgeon, patient, family => Tailored Surgery
• Measuring the common channel / entire bowel
= NO improvement in Accuracy (Std.Dev.)

71. The Goal of Weight Loss Surgery
Weight Loss

72. The Goal of Weight Loss Surgery:
Weight Loss, Of Course
But Not Too Much and
Not Too Little

73. Bariatric Weight Loss Surgery
• A History of Failure
• Jejuno-ileal Bypass
• Horizontal Gastroplasty
• Vertical Banded Gastroplasty
• Lap Band
• ? Sleeve/RNY/BPD etc.?

74. Judgment of Success or Failure
•Many Factors might be used to judge
the success or failure of Weight Loss
Surgery

75. Weight Loss
Because of Convenience and
Publications
For this presentation I will use:
% Excess Weight Loss (Imperfect)

76. Data Collection
Review of published series
Survey of participating Surgeons
For the purpose of this study Data
Collection
Operation Type, %Excess weight loss
(Mean and Standard Deviation)

77. Reminders
Some
Basics:
Simple Statistics
1. Mean
2. Standard Deviation

78. Explanation: Mean
Mean = Power/Effectiveness of a Group
of results calculated average of the
measurements:
a calculated "central" value of a set of
numbers.
To calculate: Just add up all the
Measurements, then divide by how many
Measurements there are.

79. Explanation: Standard Deviation
 Standard deviation is a number used to tell how
measurements for a group are spread out from
the average (mean), or expected value.
 A small standard deviation means that most of
the Measurements are very close to the average
(accurate)
 A high standard deviation means that the
Measurements are spread out (inaccurate)

80. “Normal Distribution”
A normal distribution, a
bell curve
Blue = Accurate Small SD
Red = Inaccurate Large
SD
All normal distributions
look like a symmetric,
bell-shaped curve

81. Bell Shaped Curve Normal Distribution
• Red Powerful
Mean = 2.0
• Blue Weak
Mean = 0.4
• Red Accurate
SD = 0.5
• Blue Inaccurate
SD = 1.0

82. Mean, Normal Distribution, Standard Deviation

83. Percent XsWtLoss, SD = Accuracy
All Roughly the same!
Mean S.D.
Band 45% + 23%
Sleeve 58% + 24%
RNY 72% + 23%
MGB 78% + 22%
BPD/SADI 82% + 24%

84. Review Survey/Review Percent XsWtLoss
Mean = Power, SD = Accuracy
Mean S.D.
Band 45% + 23%
Sleeve 58% + 24%
RNY 72% + 23%
MGB 78% + 22%
BPD/DS/SADI 82% + 24%

85. Survey/Review Percent XsWtLoss
Mean = Power, SD = Accuracy
Mean S.D.
Band 45% + 23%
Sleeve 58% + 24%
RNY 72% + 23%
MGB 78% + 22% Unique
BPD/SADI82% + 24%
MGB Can be Made
More or Less
Powerful based
upon Surgeon,
Patient and Family
preference by
modifying BP Limb
Length

86. Percent XsWtLoss, SD = Accuracy
All Roughly the same!
Mean S.D.
Band 45% + 23%
Sleeve 58% + 24%
RNY 72% + 23%
MGB 78% + 22%
BPD/SADI 82% + 24%
What Does this Mean?
It means all forms of Bariatric
Surgery vary in POWER
(Band<Sleeve<RNY<MGB<BPD-SADI)
But
All are roughly
Equally Inaccurate

87. Explanation of Weight and Malnutrition
1.Power of Bariatric Surgery = Mean
Excess Wt Loss
2. Accuracy = Std.Dev., “Spread” of the
Patients Weight Loss around the mean

88. Explanation of Weight and Malnutrition
1. To Explain malnutrition and Excess
Weight Loss
2. For this study
3. Define Malnutrition/eXcess WL (MXWL)
=
Loss of 120% of Excess Body Weight
(XsBW)

89. Calculating Risk of Malnutrition/Excess Weight
Loss
1. Power of Bariatric Surgery = Mean Excess Wt
Loss
2. Accuracy = Std.Dev., “Spread” of the Patients
Weight Loss around the mean
3. If we define Malnutrition/eXcess WL (MXWL) =
Loss of 120% of Excess Body Weight (XBW)
4.Then we can calculate risk of Malnutrition/eXcess
WL (MXWL) for each bariatric operation

90. Example: SADI
High Power (Mean)
+ 25% Standard Deviation
=>
Increased Risk Malnutrition
Simple:
More Powerful Surgery
=>
More Risk of Malnutrition

91. SADI-XWL-Mean: Mean Excess Weight Loss
Almost 10% Excess Weight Loss (7.5%)
SADI/BPD
Mean XsWL: 84%

92. Lap Band:
**VERY LOW** Risk of Malnutrition
1. Lap Band Mean Excess Wt
Loss: = 45% ** (WEAK)
2. Standard Deviation (S.D.) =
23% (Usual)
3. Malnutrition/eXcessWL
(MXWL) = Loss of 120%
XBL
4. Band: Risk
Malnutrition/eXcess WL
(MXWL) = 0.06% Very Low!

93. Sleeve:
Risk of Malnutrition
1. Sleeve Mean Excess Wt
Loss: = 58% ** (Power
Moderate)
2. Standard Deviation (S.D.) =
24%
3. Malnutrition/eXcessWL
(MXWL) = Loss of 120%
XBL
4. Sleeve: Risk
Malnutrition/eXcess WL
(MXWL) = 0.5% (Low Risk)

94. RNY: Risk of Malnutrition/Excess Weight
Loss
1. RNY Mean Excess Wt Loss:
= 72% ** (Powerful)
2. Standard Deviation (S.D.) =
23%
3. Malnutrition/eXcessWL
(MXWL) = Loss of 120% XBL
4. RNY: Risk
Malnutrition/eXcess WL
(MXWL) =
1.8% (Moderate Risk)

95. MGB (2M bypass): Risk of
Malnutrition/Excess Weight Loss
1. MGB (2M bypass) Mean
Excess Wt Loss: = 78% **
(More Powerful Surgery)
2. Standard Deviation (S.D.) =
24%
3. Malnutrition/eXcessWL
(MXWL) = Loss of 120% XBL
4. MGB (2M bypass): Risk
Malnutrition/eXcess WL
(MXWL) = 3% (Higher Risk)
5. BUT MGB Can Be Tailored!

96. BPD/SADI etc: Risk of Malnutrition/Excess
Weight Loss
1. BPD/SADI etc Mean Excess
Wt Loss: = 82% ** (Very
Powerful)
2. Standard Deviation (S.D.) =
24%
3. Malnutrition/eXcessWL
(MXWL) = Loss of 120% XBL
4. BPD/SADI etc: Risk
Malnutrition/eXcess WL
(MXWL) = **6% (Highest Risk)

97. Calculating Risk of Malnutrition/Excess Weight
Loss
•Op Est. Risk Xs Wt Loss
Band 0.06%
Sleeve 0.5%
RNY 1.8%
MGB (2M bypass) 3%
BPD/SADI 6%
Two Important Points to Note:
1.MGB with 2 meter (6 foot
Bypass)
2.BPD/SADI etc
NO More Accurate
than other operations that
DO NOT MEASURE THE
COMMON CHANNEL

98. Calculating Risk of Malnutrition/Excess Weight
Loss
1. The Power (Mean XWL)
varies by procedure
(B<S<R<M<Bpd)
Std.Dev. stays roughly the
same
(B=S=R=M=Bpd)
2. Greater power => INCREASED
Risk Malnutrition/Excess
Weight Loss
(B 0.06%<S 0.5%<R 1.8%<M 3%<Bpd
6%)
Two Important Points to Note:
1.MGB with 2 meter
(6 foot Bypass)
2.BPD/SADI etc
NO More Accurate
than other operations that
DO NOT MEASURE THE
COMMON CHANNEL

99. ASSOCIATION OF BYPASS LIMB
LENGTH AND ONE YEAR WEIGHT
LOSS IN 4,114 MINI-GASTRIC
BYPASS PATIENTS
Dr Rutledge, Know this Since 2011
Poster Number: P.185,
Your Presentation takes place: Date: 01.09.2011,
Session: P8 / GASTRIC BYPASS / 16.00-17.00

100. BP Limb & Weight Loss: Results
• Weight loss following MGB followed a
logarithmic decline though the end of the first
year and then leveled off.
• Bypass limb length varied from
0.5 - 3 meters.
• Weight loss Increases as
Bypass limb length Increase

101. BP Limb & Weight Loss: Results
• A multivariate regression model using bypass
length and Preop weight improved the predictive
value of the model,
• Wt Loss = 13.04 + Bypass*6.98 +
Pre Op Wt * 0.25
• (Fig. 2, p<0.0001, r2= 0.38)

102. The Myth of the Common Channel

103. Myth of the Common Channel
Measuring the Common Channel will
improve the outcomes (accuracy of weight
loss) following bariatric surgery
1.No supporting evidence
2.This study shows procedures/surgeons
using the common channel DO NOT
improve weight loss accuracy

104. Conclusions
1. Bariatric Operation based on published reports
and survey data are more or less powerful
Band < Sleeve < RNY < MGB < = BPD/SADI etc
2. All Bariatric Procedures studied are roughly
equally accurate/inaccurate
3. Measuring the Common Channel as part of
bypass operation does NOT appear to improve or
affect Accuracy of Bariatric Procedures