Effect of Limb Length Ratio on Roux-en-Y Gastric Bypass Outcomes (CLIMB II Study) (CLIMBII)

March 18, 2026 updated by: Salvador Navarrete
The investigators propose a randomized controlled trial comparing BP and roux limb lengths measuring 30 and 15% respectively of patient's total small bowel length versus current standard practice using fixed lengths. The findings would provide further insight into feasibility of standardizing RYGB limb lengths and optimizing resultant weight loss and metabolic effects. The investigators hypothesize RYGB with ratio-adjusted limb lengths (aRYGB) will result in higher total weight loss and resolution of metabolic syndrome comorbidities, including diabetes, hyperlipidemia, and hypertension compared to standard fixed-length RYGB (sRYGB). The study will also utilize the Short Form Rand 36-Item Health Survey (SF36) to determine differences in postoperative quality of life metrics.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study will be a prospective, randomized controlled trial with a 1:1 recruitment allocation ratio. Patients will be randomized to Standard fixed-length RYGB (sRYGB) or ratio-adjusted limb lengths (aRYGB) once the total small bowel length (TSBL) is fully counted intraoperatively.

sRYGB will serve as the control group which will utilize BP and roux limb lengths of 100cm and 100cm, respectively. For the treatment group, aRYGB will incorporate a BP limb length measuring 30% and a roux limb of 15% of total small bowel length each.

Outcomes to be investigated:

Specific Aim 1: To determine significantly increased Total Weight Loss (TWL) after aRYGB compared to sRYGB in morbidly obese patients Given current understanding that weight loss after RYGB is mediated, at least in part, by a malabsorptive process, the investigators hypothesize that TWL will be greater after aRYGB versus sRYGB. As per standard of care at our institute, routine postoperative follow-up in the multidisciplinary Bariatric clinic will occur every 6 months (± 14 days) or more frequently as clinically indicated for the first two years postoperatively followed by yearly thereafter. Weight will be recorded in kilograms and a BMI will be calculated by the ratio of patient weight in kilograms over patient height in meters squared. Postoperative TWL will then be measured postoperatively at 6, 12, 24, 60 months from surgery.

Specific Aim 2: To compare rates of Diabetes Mellitus (DM) resolution between aRYGB Vs SRYGB by DM subgroup analysis Of the many metabolic changes that occur after bariatric surgery, one of the most salient effects include a rapid and effective resolution of DM. This has been extensively studied in context of various bariatric surgeries, including RYGB by our institution as previously described by the STAMPEDE trial. Significant reduction of HbA1C and improvement in insulin sensitivity was noted as early as six to 12 months postoperatively. As such, this study proposes measurement of the following two metrics at 6, 12, 24, 60 months postoperatively: 1) proportion of subjects achieving HbA1C less than or equal to 6.5%; and, 2) proportion of subjects able to wean and/or discontinue glycemic control medications.

Specific Aim 3: To investigate the relative postoperative efficacy of aRYGB compared to sRYGB on alleviating metabolic syndrome in morbid obesity Metabolic syndrome is a constellation of diagnoses including Hypertension (HTN) and Hyperlipidemia (HLD), which posit significant risk of medical comorbidities such as DM, coronary disease, and strokes. As such, addressing these conditions in morbidly obese patients confers a significant health benefit and decreases overall morbidity. This secondary outcome will be measured by comparing pre- versus postoperative serum lipid levels and proportion of patients requiring less antihypertensives 6, 12, 24, 60 months postoperatively.

Specific Aim 4: To investigate the presence of postoperative vitamin and nutritional deficiencies between the groups.

These secondary outcomes will be addressed comparing the vitamin levels between the groups at 6, 12, 24, 60 months postoperatively.

Additional outcomes proposed include evaluation of postoperative quality of life as captured by the Impact of Weight on Quality of Life-Lite-Clinical Trials (IWQOL-Lite-CT) survey as validated and effectively used in previous investigative bariatric studies. Responses will be tracked and obtained preoperatively and at various postoperative time points including Post-Operative Day (POD) 30 (± 15 days) and POD 365 (± 90 days). The investigators will furthermore track postoperative complications and adverse events, as measured by the Comprehensive Complications Index in addition to instances where additional bariatric surgical interventions are pursued.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
262

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Salvador Navarrete, MD
  • Phone Number: 2162199211
  • Email: navarrs@ccf.org

Study Contact Backup

Study Locations

  • United States
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Recruiting
        • Cleveland Clinic
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • morbidly obese patients (defined by BMI between 40 and 60).
  • Patient who understands and accepts the need for a long-term follow-up.
  • Patient who agrees to be included in the study

Exclusion Criteria:

  • individuals unable to understand and sign a written consent form
  • patients with history of previous bariatric surgery procedures
  • presence of a severe and evolutive life threatening pathology unrelated to obesity
  • previous gastric or small bowel resection
  • active cancer
  • pregnancy or desired to be pregnant during the study
  • mentally unbalanced patients under supervision or guardianship, patient unable to give consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: aRYGB
BP and roux limb lengths measuring 30% and 15% respectively of patient's total small bowel length.
Procedure: Surgery
Biliopancreatic limb and roux limb lengths measuring 30 and 15% respectively of patient's total small bowel length in RYGB
Active Comparator: sRYGB
Standard fixed-length RYGB
Procedure: Surgery
Biliopancreatic limb and roux limb lengths measuring 30 and 15% respectively of patient's total small bowel length in RYGB

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
To determine change in TWL after aRYGB compared to sRYGB in morbidly obese patients
Time Frame: 6,12,24 and 60 months from surgery
Measured in kilograms
6,12,24 and 60 months from surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
To compare rates of DM resolution between aRYGB Vs sRYGB by DM subgroup analysis
Time Frame: 6,12,24 and 60 months from surgery
Measured by subjects achieving HbA1c less than or equal to 6.5% and subjects able to wean and/or discontinue glycemic control medications
6,12,24 and 60 months from surgery
To investigate postoperative efficacy rates of aRYGB compared to sRYGB on alleviating metabolic syndrome in morbid obesity
Time Frame: 6,12,24 and 60 months from surgery
Measured by a change in serum lipid levels and subjects requiring less antihypertensives
6,12,24 and 60 months from surgery
To investigate the presence of postoperative vitamin and nutritional deficiencies between the groups.
Time Frame: 6,12,24 and 60 months from surgery
6,12,24 and 60 months from surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Salvador Navarrete

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Salvador Navarrete, MD, The Cleveland Clinic

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 12, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 11, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 11, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 19, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 27, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 5, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 20, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 23-1228

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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