Gastric Bypass SurgeryNCT07347093
Reversal of Roux-en-Y Gastric Bypass: A Swedish National Cohort Study
An observational study of Gastric Bypass Surgery and Revisional Bariatric Surgery, run by Vrinnevi Hospital at 1 site in Sweden.
Trial summary
Objective: To investigates incidence, indications, symptom relief, complications, and weight outcomes after Roux-en-Y gastric bypass (RYGB) reversal. Background: RYGB is an effective treatment for obesity, but in rare cases may be associated with severe long-term complications requiring RYGB reversal. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Gastric Bypass Surgery, Revisional Bariatric Surgery, Complications After Bariatric Surgery
- How many people
- 199 participants
- Where
- 1 siteSweden
- Study dates
- 1 Nov 2025to 31 May 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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: National registry-based cohort
Who may be able to join
- Adult patients (≥ 18years) who underwent reversal of RYGB between 2007 and 2023.
Who cannot join
- Emergency reversal due to bowel ischemia
- Reversal following other bariatric procedures (e.g. gastric banding)
- Partial/functional reversals (e.g., gastro-gastric fistula or anastomosis between the Roux-limb and gastric remnant, without full reversal of RYGB)
Trial locations and contacts
1 site in 1 country.
About this study
Objective:
To investigates incidence, indications, symptom relief, complications, and weight outcomes after Roux-en-Y gastric bypass (RYGB) reversal.
Background:
RYGB is an effective treatment for obesity, but in rare cases may be associated with severe long-term complications requiring RYGB reversal. Evidence on incidence and outcomes is limited.
Methods:
This nationwide, multi-center, retrospective cohort study included all patients undergoing RYGB reversal in Sweden between 2007 and 2023. Data were obtained from the Scandinavian Obesity Surgery Registry (SOReg) and medical records.
- Conditions
- Gastric Bypass Surgery, Revisional Bariatric Surgery, Complications After Bariatric Surgery
- Keywords
- Roux-en-Y gastric bypass, Anatomical reversal, Indications, Complications, Outcomes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Adults (≥ 18years) who underwent reversal of RYGB | Included patients were adults (≥ 18years) who underwent reversal of RYGB between 2007 and 2023. Exclusion criteria included emergency reversal due to bowel ischemia, reversal following other bariatric procedures (e.g. gastric banding), or partial/functional reversals (e.g., gastro-gastric fistula or anastomosis between the Roux-limb and gastric remnant, without full reversal of RYGB) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Symptom relief
Symptom relief is classified as no, partial, or complete improvement.
Complete improvement was defined as full resolution of the index symptom (e.g., cessation of hypoglycemia, pain-free status without analgesics).
Partial improvement denoted a clinically meaningful reduction in symptom severity or frequency that did not meet criteria for complete resolution.
No improvement indicated persistent symptoms.
Measured: Through study completion, an average of 2 years.
Secondary outcomes (5)
Indications for surgery
Indications are categorized as abdominal pain, malnutrition, gastrointestinal symptoms, post-bariatric hypoglycemia, and psychological distress, and reported as number (frequencies).
Measured: Through study completion, an average of 2 years.
Weight outcome after surgery
Weigth [in kilograms] will be reported at baseline (before surgery), at one year follow-up, and two-year follow-up.
Measured: Through study completion, an average of 2 years.
Complications
Complications after surgery are registered as any complication and major complication (defined as Clavien-Dindo classification >=3b), presented as number (frequencies).
Measured: At 30-day follow-up and one-year follow-up after surgery.
Height
Height (in meters) will be used to report BMI (in kg/m2).
Measured: Through study completion, an average of 2 years
BMI
Weight (in kilograms) and height (in meters) will be combined to report BMI (in kg/m2) at baseline (before surgery), at one year follow-up, andat two-year follow-up.
Measured: Through study completion, an average of 2 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jan 2026
- Study start1 Nov 2025
- Primary completion31 Mar 2026 (estimated)
- Study completion31 May 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gastric Bypass SurgeryStudies of the same condition, open and under way.
- 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
- Retrospective
- Enrolment
- 199 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vrinnevi Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ellen Andersson, Vrinnevi Hospital
- Investigators
- Ellen A Andersson, MD, Principal investigator, Department of Surgery, Vrinnevi Hospital, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07347093
- Sponsor's protocol ID
- Dnr 2022-01827-01
- Status last verified
- Jan 2026
- First submitted
- 16 Dec 2025
- Last updated
- 20 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Since reversal of RYGB is a rare procedure the risk of identifying individual patients is considerable even if data are pseudonymized.
Study at a glance
From the registry record, last updated by the sponsor on 20 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Reversal of Roux-en-Y Gastric Bypass: A Swedish National Cohort Study
- ClinicalTrials.gov ID
- NCT07347093
- Acronym / sponsor ID
- Dnr 2022-01827-01
- Conditions
- Gastric Bypass Surgery, Revisional Bariatric Surgery, Complications After Bariatric Surgery
- Keywords
- Roux-en-Y gastric bypass, Anatomical reversal, Indications, Complications, Outcomes
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 199 participants (actual)
- Lead sponsor
- Vrinnevi HospitalUniversity, hospital or other
- Study start
- 1 Nov 2025 (actual)
- Primary completion
- 31 Mar 2026 (estimated)
- Study completion
- 31 May 2026 (estimated)
- First posted
- 16 Jan 2026 (actual)
- 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.
Objective:
To investigates incidence, indications, symptom relief, complications, and weight outcomes after Roux-en-Y gastric bypass (RYGB) reversal.
Background:
RYGB is an effective treatment for obesity, but in rare cases may be associated with severe long-term complications requiring RYGB reversal. Evidence on incidence and outcomes is limited.
Methods:
This nationwide, multi-center, retrospective cohort study included all patients undergoing RYGB reversal in Sweden between 2007 and 2023. Data were obtained from the Scandinavian Obesity Surgery Registry (SOReg) and medical records.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adults (≥ 18years) who underwent reversal of RYGB | – | –Included patients were adults (≥ 18years) who underwent reversal of RYGB between 2007 and 2023. Exclusion criteria included emergency reversal due to bowel ischemia, reversal following other bariatric procedures (e.g. gastric banding), or partial/functional reversals (e.g., gastro-gastric fistula or anastomosis between the Roux-limb and gastric remnant, without full reversal of RYGB) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- National registry-based cohort
Key inclusion criteria (1 listed)
- Adult patients (≥ 18years) who underwent reversal of RYGB between 2007 and 2023.
Key exclusion criteria (3 listed)
- Emergency reversal due to bowel ischemia
- Reversal following other bariatric procedures (e.g. gastric banding)
- Partial/functional reversals (e.g., gastro-gastric fistula or anastomosis between the Roux-limb and gastric remnant, without full reversal of RYGB)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Symptom relief
Time frame: Through study completion, an average of 2 years.
Symptom relief is classified as no, partial, or complete improvement. Complete improvement was defined as full resolution of the index symptom (e.g., cessation of hypoglycemia, pain-free status without analgesics). Partial improvement denoted a clinically meaningful reduction in symptom severity or frequency that did not meet criteria for complete resolution. No improvement indicated persistent symptoms.
5 secondary outcomes
Indications for surgery
Time frame: Through study completion, an average of 2 years.
Weight outcome after surgery
Time frame: Through study completion, an average of 2 years.
Complications
Time frame: At 30-day follow-up and one-year follow-up after surgery.
Height
Time frame: Through study completion, an average of 2 years
BMI
Time frame: Through study completion, an average of 2 years.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jan 2026.
- Individual participant dataSharing planned: No. Since reversal of RYGB is a rare procedure the risk of identifying individual patients is considerable even if data are pseudonymized.
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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.
Ellen A Andersson, MD principal investigator
Department of Surgery, Vrinnevi Hospital, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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 Gastric Bypass Surgery and Revisional Bariatric Surgery, run by Vrinnevi Hospital at 1 site in Sweden.
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 1 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: under way, not looking for participants, as of the sponsor's last update on 20 Jan 2026. 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 Sweden. 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?
This study is still under way. Results are not available in the source record yet.
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?
Symptom relief (time frame: Through study completion, an average of 2 years.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 20 Jan 2026.