Determinants of Fat Malabsorption After Roux-en-Y Gastric Bypass

Study Overview
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Brief Summary
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The purpose of this study is to determine whether or not the length of the biliopancreatic limb of the Roux-en-Y anastamosis plays a critical role in the development of malabsorption after gastric bypass for treatment of severe obesity.

Detailed Description
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Successful surgical treatment of severe obesity by RYGB is believed to require a procedure that (a) restricts the consumption of combustible food energy, and (b) reduces the intestinal absorption of food energy that is consumed. However, with RYGB operations that are currently employed, many patients do not develop the malabsorption they presumably require to produce good long term control of their body weight. It is important to find a way to do RYGB surgery in a way that consistently produces a moderate degree of fat malabsorption. Patients who are scheduled to receive a RYGB for treatment of severe obesity will be randomly assigned to receive 2 variations of the standard operation. The stomach and duodenal bypass, and the creation of a small gastric pouch will be exactly the same for all patients. There will be differences in the two jejunal limbs which create the Roux-en-Y anastomosis. In Procedure A, the Roux limb length will be 150 cm, and the biliopancreatic limb will contain 40 cm of jejunum. In Procedure B, the Roux limb length will be 110 cm and the biliopancreatic limb will contain 80 cm of jejunum. The total length of jejunum in both limbs is 190 cm in both procedures. Thus, the only difference between procedures A and B is that B procedure has a larger percentage of jejunum in the biliopancreatic limb (80/190=42%) than procedure A (40/190 = 21%). A total of 20 patients will be studied, 10 with each procedure. Before and after RYGB, the patients will be studied in a clinical research laboratory. Dietary intake and intestinal absorption of fat, protein, carbohydrate and combustible energy will be measured by metabolic balance techniques for 72 hours. We hypothesize that fat malabsorption after bypass will be greater and more consistent in patients who receive the longer biliopancreatic limb than in the patients who receive the longer Roux limb.

Official Title
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Surgical Treatment of Severe Obesity by Roux-en-Y Gastric Bypass: a Randomized Prospective Study on the Effect of Reciprocal Changes in Y-limb Lengths on Intestinal Absorption of Dietary Fat, Protein and Carbohydrate.

Conditions
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Severe Obesity

Intervention / Treatment
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* Procedure: RYGB for surgical treatment of severe obesity


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with severe obesity (BMI equal to or greater than 50) who have been scheduled to receive Roux-en-Y gastric bypass. Exclusion Criteria: Previous abdominal surgery, chronic diarrhea, and severe constipation.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: long biliopancreatic limb, 75 cm<br> | Procedure: RYGB for surgical treatment of severe obesity<br>* Twenty severely obese patients who have been scheduled to receive long limb RYGB will be enrolled in the study. By randomization, 10 patients will have a biliopancreatic limb that includes 40 cm of jejunum and a Roux limb that contains 150 cm of jejunum. The other 10 patients will receive a biliopancreatic limb that contains 75 cm of jejunum and a Roux limb of 115 cm.<br>|
| Active Comparator: long Roux limb, 150 cm<br> | Procedure: RYGB for surgical treatment of severe obesity<br>* Twenty severely obese patients who have been scheduled to receive long limb RYGB will be enrolled in the study. By randomization, 10 patients will have a biliopancreatic limb that includes 40 cm of jejunum and a Roux limb that contains 150 cm of jejunum. The other 10 patients will receive a biliopancreatic limb that contains 75 cm of jejunum and a Roux limb of 115 cm.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Selective fat malabsorption | To learn how to create an operation resulting in the predominance of fat malabsorption over protein malabsorption. | 1 year after RYGB surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Malabsorption after RYGB, Fat Malabsorption and maldigestion, Obesity surgery, Bariatric surgery