Prediction of Weight Loss Following The Mini-Gastric Bypass: Multivariate Regression Modeling Robert Rutledge, K Kular, N. Manchanda CLOS Center For Laparoscopic Obesity Surgery, MGB Review Corp

1. Prediction of Weight Loss
Following The Mini-Gastric Bypass:
Multivariate
Regression Modeling
Robert Rutledge, K Kular, N. Manchanda
CLOS Center For Laparoscopic Obesity
Surgery, MGB Review Corp

2. Seeking Perfection;
Power and Safety in Bariatric Surgery
Titrating the Bilio-Pancreatic Limb
Length via the Technique of
Rutledge and the Outcomes of
Weight Loss Nine Years After the
Mini-Gastric Bypass

3. Introduction:
The goal is clear we wish to offer powerful and effective
weight loss while avoiding the complications such as too
much, that is to say excessive weight loss.
The purpose of the present study was designed to assess
the outcomes of a sample of Mini-Gastric Bypass patients
that were treated following the protocol of Rutledge,
titrating the Bilio-pancreatic limb to better adjust the power
of the procedure to the needs of the patient.

4. Methods
20 years of MGB Rutledge has provided guidelines
on the performance of the MGB.
The surgical team followed these guidelines,
tailoring/titrating the Bilio-Pancreatic limb based upon
several patient and societal factors to modulate the
power of the operation to seek to obtain a goal of
maximal weight loss and minimal complications.

5. Methods:
To assess the performance of this case
series a sample of 212 patients were
selected that were 9 years after surgery.

6. Methods:
The accuracy of the final weight judged as
the difference at 9 years between the
estimated ideal body weight and the weight
at the time of the study follow up.

7. Methods
Outcomes were judged as
excellent if the patients final weight 9 years after MGB was
between the Ideal body weight and 15 kg above the IBW,
Good between IBW+15 and IBW +30
Average if Final Weight between IBW +30 and IBW + 40 or
=IBW and IBW-5 and
poor if other weights

8. Results
In short the patient population mean preop weight
was 127kg + 36 kg,
the Ideal Body Weight (BW) was 62kg + 12.7.
The mean weight loss at 9 years was 49kg + 31 and
the mean weight at 9 years was 78kg + 17.
The difference between the IBW and 9 year weight
was mean 16kg + 11.

9. Selection of the BP Limb Length
20
23
9
20
78
6
1
10
8
1
4
12
1 2 1
8
5 4
0
10
20
30
40
50
60
70
80
120 150 180 210 240 270 300 330
Selection of BP Limb Length

10. BP Limb Length => % Total Weight Loss
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
100 150 200 250 300 350
BP Limb Length & %Total Wt Loss

11. BP Limb Length vs %Excess Wt. Loss
Correlation R = 0.81
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
100 150 200 250 300 350
BP Limb Length vs %EWL
R = 0.81
Longer Bypass Limb
=> More Weight Loss

12. Patients Final Weights @ 9 Years
0
20
40
60
80
100
120
140
160
180
0 50 100 150 200
Patient End Weight 9 Years

13. Ideal Weight vs Actual 9 yr Weight
0
20
40
60
80
100
120
140
160
0 50 100 150 200
Ideal Body Weight vs MGB 9 year Body Weight
IdealBW kg 9YrWt Linear (IdealBW kg) Linear (9YrWt)
The difference
between IBW &
9 year weight
16kg

14. BP Limb Length & Weight Loss
• BP Limb Length: 191.6 + 52.2 Mean Std
• Pre-op weight kg: 127.1 + 36.5
• Weight Loss at 9yrs: 48.8 + 30.7
• Ending weight 9 yr: 78.3 + 16.9

15. Linear Regression Analysis
• ŷ = -0.34X1 + 0.67X2 + 57.7
• Y = Predicted weight lost
• x1 = BP Limb Length
• x2 = Pre-op Weight

16. Quality of the MGB
Perfect is the Enemy of Good
-60
-40
-20
0
20
40
60
1 51 101 151 201
ABIBW

17. Results
It is very important to note the
wide standard deviation in the outcomes
matching other studies and importantly
demonstrates that if the power of the MGB had
been increased at all the number of patients
with excessive weight loss would have
increased markedly.

18. Conclusions
Perfection, especially in bariatric surgery is an
unattainable goal.
This study as well as other demonstrates that a
tailored BP Limb length can result in excellent
outcomes but a longer or more powerful MGB would
have resulted in more excessive wight loss and the
need for revisions.

19. Conclusions
The weight loss in this group is
excellent and the risk of excessive
power with poor outcomes in
fortunately rare suggesting this
approach is near ideal for the limits of
present day bariatric surgery.