MalnutritionNCT02872493
Small Bowel Length and Bariatric Surgery Outcomes
An observational study of Malnutrition and Obesity, run by Vanderbilt University Medical Center at 1 site in United States.
Trial summary
The purpose of this study is to determine whether or not the total length of small intestine effects outcomes after bariatric surgery in a cohort of patients preoperatively and up to ten years postoperatively. Roux-en-Y gastric bypass and vertical sleeve gastrectomy will be the surgical groups in this study. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Malnutrition, Obesity, Weight Loss
- What is being tested?
- Small bowel length measurement
- Type of treatment
- Surgery or procedure
- How many people
- 470 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2016to Mar 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: We will be studying two cohorts of patients prior to and following either Roux-en-Y gastric bypass or vertical sleeve gastrectomy for up to ten years.
Who may be able to join
- Patients undergoing laparoscopic bariatric surgery, either vertical sleeve gastrectomy or Roux-en-Y gastric bypass
- Able to give informed consent
Who cannot join
- Prior small intestine resection.
- Inability to safely obtain total small intestinal length measurements in the operating room.
- Any small bowel tethering due to intestinal adhesions identified in the operating room.
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
Official title: Observational Study of the Effect of Small Intestine Length on Bariatric Surgical Patient Outcomes
The purpose of this study is to determine whether or not the total length of small intestine effects outcomes after bariatric surgery in a cohort of patients preoperatively and up to ten years postoperatively. Roux-en-Y gastric bypass and vertical sleeve gastrectomy will be the surgical groups in this study. We aim to determine if bowel length has a significant effect on long term weight loss or other nutritional deficiencies in this bariatric cohort.
Read the detailed description
Bariatric surgery (also known as "weight loss surgery") is the most effective treatment for obesity as well as a number of other obesity-related conditions, including type 2 diabetes, hypertension, and hypercholesterolemia. Interestingly, not all patients respond with significant weight loss following surgery and some patients even lack much weight loss at all over the long-term. Even though variability in treatment response is observed in a variety of diseases, the biological basis for this variability in weight loss after bariatric surgery is poorly understood. Recent data from our group as well as others, however, suggest that differences in the total length of the small intestine may significantly contribute to these differences in weight loss over time. For example, Roux-en-Y gastric bypass is thought to exert its weight loss effect because of a bypass of small intestine that causes a degree of nutrient malabsorption. The bypassed small intestine (<100cm) is near the proximal end of the intestines closest to the stomach. Hypothetically, an individual with the greater total small intestine length may not benefit as much from the bypass as someone who has a much shorter length of total small intestine. Whether or not this hypothetical relationship is true remains unknown, but a recent study demonstrated that small intestine length does differ significantly between individuals with lengths ranging from 300cm to >1200cm. The total length of small intestine is not routinely measured during any bariatric procedure, as the lengths of the bypass limbs are determined from the portion of the intestines closest to the stomach. The purpose of this study is to determine whether the amount of total small intestine significantly affects weight loss in patients undergoing bariatric surgery - both the Roux-en-Y gastric bypass (RYGB) or the Vertical Sleeve Gastrectomy (VSG). If there is a significant effect of total small intestine length on long-term weight loss in bariatric patients, then it would justify the conduct of a further study to determine whether or not these operations should be performed differently in individuals to account for the differences in small intestine length. This is an observational study that will be looking at body weight (primary endpoint) and other nutritional endpoints (other pre-specified outcome measure) over time up to ten years in this patient cohort. The body weight measurements and any laboratory data will be collected that are part of the routine clinical care of these patients.
- Conditions
- Malnutrition, Obesity, Weight Loss, Micronutrient Deficiency
- Being tested
- Small bowel length measurement
- Keywords
- obesity, bariatric surgery, bowel length
- Medical subject headings
- Malnutrition, Obesity, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Small bowel length measurementProcedure or surgery
The total length of the small bowel with be measured at the time of the bariatric surgical operation.
| Study group | Role | What they receive |
|---|---|---|
| RYGB | Roux-en-Y Gastric Bypass - these are patients that undergo a Roux-en-Y gastric bypass operation for their bariatric operation. Receives: Procedure: Small bowel length measurement | |
| VSG | Vertical Sleeve Gastrectomy - these are patients that undergo a vertical sleeve gastrectomy operation for their bariatric operation. Receives: Procedure: Small bowel length measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Body Weight
Body weight will be measured preoperatively (within 30 days of the operation) as the baseline body weight, then postoperatively up to ten years from the time of initial surgery. Measurements will be made per routine clinical care and not solely for research purposes. Exact time points before and after surgery that body weight will be measured, except for the day of surgery, will differ between patients in the study.
Change in body weight over time will be measured annually, adjusted for baseline body weight at the time of surgery.
Regression will be used to test for a significant interaction of "total bowel length" and "body weight" over time in the patient cohorts (RYGB vs. VSG) - this is our primary outcome measurement. We are examining whether there is a significant interaction between any change in body weight over time and the small bowel length in the patient cohorts.
Measured: Up to 10 years postoperatively as measured for routine clinical care
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2016 (estimated)
- Study startAug 2016
- Primary completionMar 2025
- Study completionMar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for MalnutritionStudies of the same condition, open and under way.
- More trials run by Vanderbilt University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 470 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Charles R. Flynn, Vanderbilt University Medical Center
- Investigators
- Charles R Flynn, PhD, Principal investigator, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02872493
- Sponsor's protocol ID
- 160971
- Status last verified
- Jul 2025
- First submitted
- 8 Aug 2016
- Last updated
- 8 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Albaugh VL, Weinberg JL, Yu D, Spann MD, Williams DB, Samuels JM, Flynn CR, English WJ. Total Alimentary Limb Length Is Not Associated with Weight Loss Following Proximal Roux-en-Y Gastric Bypass. Obes Surg. 2025 May;35(5):1693-1701. doi: 10.1007/s11695-025-07817-5. Epub 2025 Mar 27.
PubMed 40146457
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Observational Study of the Effect of Small Intestine Length on Bariatric Surgical Patient Outcomes
- ClinicalTrials.gov ID
- NCT02872493
- Acronym / sponsor ID
- 160971
- Conditions
- Malnutrition, Obesity, Weight Loss, Micronutrient Deficiency
- Keywords
- obesity, bariatric surgery, bowel length
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 470 participants (actual)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Study start
- Aug 2016
- Primary completion
- Mar 2025 (actual)
- Study completion
- Mar 2025 (actual)
- First posted
- 19 Aug 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine whether or not the total length of small intestine effects outcomes after bariatric surgery in a cohort of patients preoperatively and up to ten years postoperatively. Roux-en-Y gastric bypass and vertical sleeve gastrectomy will be the surgical groups in this study. We aim to determine if bowel length has a significant effect on long term weight loss or other nutritional deficiencies in this bariatric cohort.
Detailed description
Bariatric surgery (also known as "weight loss surgery") is the most effective treatment for obesity as well as a number of other obesity-related conditions, including type 2 diabetes, hypertension, and hypercholesterolemia. Interestingly, not all patients respond with significant weight loss following surgery and some patients even lack much weight loss at all over the long-term. Even though variability in treatment response is observed in a variety of diseases, the biological basis for this variability in weight loss after bariatric surgery is poorly understood. Recent data from our group as well as others, however, suggest that differences in the total length of the small intestine may significantly contribute to these differences in weight loss over time. For example, Roux-en-Y gastric bypass is thought to exert its weight loss effect because of a bypass of small intestine that causes a degree of nutrient malabsorption. The bypassed small intestine (<100cm) is near the proximal end of the intestines closest to the stomach. Hypothetically, an individual with the greater total small intestine length may not benefit as much from the bypass as someone who has a much shorter length of total small intestine. Whether or not this hypothetical relationship is true remains unknown, but a recent study demonstrated that small intestine length does differ significantly between individuals with lengths ranging from 300cm to >1200cm. The total length of small intestine is not routinely measured during any bariatric procedure, as the lengths of the bypass limbs are determined from the portion of the intestines closest to the stomach. The purpose of this study is to determine whether the amount of total small intestine significantly affects weight loss in patients undergoing bariatric surgery - both the Roux-en-Y gastric bypass (RYGB) or the Vertical Sleeve Gastrectomy (VSG). If there is a significant effect of total small intestine length on long-term weight loss in bariatric patients, then it would justify the conduct of a further study to determine whether or not these operations should be performed differently in individuals to account for the differences in small intestine length. This is an observational study that will be looking at body weight (primary endpoint) and other nutritional endpoints (other pre-specified outcome measure) over time up to ten years in this patient cohort. The body weight measurements and any laboratory data will be collected that are part of the routine clinical care of these patients.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| RYGB | – | Procedure: Small bowel length measurementRoux-en-Y Gastric Bypass - these are patients that undergo a Roux-en-Y gastric bypass operation for their bariatric operation. |
| VSG | – | Procedure: Small bowel length measurementVertical Sleeve Gastrectomy - these are patients that undergo a vertical sleeve gastrectomy operation for their bariatric operation. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- We will be studying two cohorts of patients prior to and following either Roux-en-Y gastric bypass or vertical sleeve gastrectomy for up to ten years.
Key inclusion criteria (2 listed)
- Patients undergoing laparoscopic bariatric surgery, either vertical sleeve gastrectomy or Roux-en-Y gastric bypass
- Able to give informed consent
Key exclusion criteria (3 listed)
- Prior small intestine resection.
- Inability to safely obtain total small intestinal length measurements in the operating room.
- Any small bowel tethering due to intestinal adhesions identified in the operating room.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Small bowel length measurementThe total length of the small bowel with be measured at the time of the bariatric surgical operation. | Procedure or surgery | RYGB, VSG |
Primary outcome
Body Weight
Time frame: Up to 10 years postoperatively as measured for routine clinical care
Body weight will be measured preoperatively (within 30 days of the operation) as the baseline body weight, then postoperatively up to ten years from the time of initial surgery. Measurements will be made per routine clinical care and not solely for research purposes. Exact time points before and after surgery that body weight will be measured, except for the day of surgery, will differ between patients in the study. Change in body weight over time will be measured annually, adjusted for baseline body weight at the time of surgery. Regression will be used to test for a significant interaction of "total bowel length" and "body weight" over time in the patient cohorts (RYGB vs. VSG) - this is our primary outcome measurement. We are examining whether there is a significant interaction between any change in body weight over time and the small bowel length in the patient cohorts.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jul 2025.
- Results publication: PubMed 40146457Albaugh VL, Weinberg JL, Yu D, Spann MD, Williams DB, Samuels JM, Flynn CR, English WJ. Total Alimentary Limb Length Is Not Associated with Weight Loss Following Proximal Roux-en-Y Gastric Bypass. Obes Surg. 2025 May;35(5):1693-1701. doi: 10.1007/s11695-025-07817-5. Epub 2025 Mar 27.
- Total Alimentary Limb Length Is Not Associated with Weight Loss Following Proximal Roux-en-Y Gastric BypassLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Charles R Flynn, PhD principal investigator
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Malnutrition and Obesity, run by Vanderbilt University Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Body Weight (time frame: Up to 10 years postoperatively as measured for routine clinical care). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02872493, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jul 2025.