Intraoperative Measuring of Small Bowel Length Compared to Measuring by Magnetic Resonance Imaging (MRI) in Morbid Obese Patients

Study Overview
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Brief Summary
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An important step during a gastric bypass operation for the treatment of morbid obesity is the measuring of the small bowel length. At several reoperations we found a length increase of the lowest part of the small intestine of up to 80% compared to the measured length at the initial operation. On the one hand, this reflects a normal technical error of small bowel measuring due to the variable state of contraction of the bowel, but on the other hand, it could also be due to a compensatory increase in intestinal length after the operation. New protocols allow measuring of the small bowel length by MRI. Comparing the preoperative and later on several postoperative measurements by MRI with the initial intraoperative length measuring should allow to validate the new MRI protocol and in the same time quantify the eventual small bowel length increase. We plan to include 20 patients in this study.

Detailed Description
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Background: An important step during a gastric bypass operation for the treatment of morbid obesity is the measuring of the small bowel length in order to define the lengths of the alimentary, biliopancreatic and common channel. The measuring itself is technically simple but has always an error due to the variable state of contraction of the small bowel. In distal gastric bypass a common channel length of 100 to 150 cm is chosen which induces an iatrogenic short bowel syndrome. At several reoperations we found a length increase of the common channel of up to 80% compared to the measured length at the initial operation. Former studies seem to indicate that an adaptation of small bowel length may occur in animals with short bowel syndrome or after intestinal bypass surgery. Longterm results of gastric bypass surgery often show weight regain after 3 to 5 years which could be due to the afore mentioned compensatory mechanism. Newer MRI protocols allow for non-invasive measurement of the small bowel length. Comparing the preoperative and later on several postoperative measurements by MRI with the initial intraoperative length measuring should allow to validate the new MRI protocol and in the same time quantify the eventual small bowel length increase. Objective: In-vivo verification of small bowel length measurements made by MRI, quantification of a possible increase of the common channel length in the long run after distal gastric bypass. Methods: The preoperative small bowel length measurement by MRI is compared to the length measured intraoperatively. MRIs before discharge postoperatively as well as after 6 and 12 months are used to detect an eventual increase of the common channel length.

Official Title
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Prospective Study for the Quantification of a Compensatory Increase in Small Bowel Length After Roux-en-Y Gastric Bypass in Morbid Obese Patients by Pre- and Postoperative Length-Measuring With MRI Compared to Intraoperative Length-Measuring

Conditions
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Morbid Obesity, Weight Loss

Intervention / Treatment
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* Procedure: Distal gastric bypass


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: morbid obese patient scheduled for distal gastric bypass informed consent for operation and study obtained Exclusion Criteria: history of former small bowel resection weight > 150 kg history of claustrophobia general contraindications for MRI (pacer, joint prosthesis, ear implant, etc.)

Ages Eligible for Study
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Minimum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Distal gastric bypass | Procedure: Distal gastric bypass<br>* Distal gastric bypass<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Small bowel length in vivo compared to measurements by MRI |  | preoperative, previous to hospital discharge, 6 and 12 months postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compensatory increase of the common channel (small bowel) after distal bypass |  | 12 months postoperative | 
| Correlation of longterm weight regain with increase of common channel length |  | 12 months postoperative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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morbid obesity, small bowel, gastric bypass, weight loss