Obesity, MorbidNCT07880691
Weight Loss and Comorbidity Outcomes After Revisional Bariatric Surgery
An observational study of Obesity, Morbid and Weight Regain After Bariatric Surgery, run by Kasr El Aini Hospital.
Trial summary
Some people who have had weight-loss (bariatric) surgery do not lose enough weight, regain much of the weight they lost, see obesity-related diseases such as diabetes or high blood pressure return, or develop complications of the first operation. Many of them need a second, revisional operation. Read more about this study
- Who is it for?
- Ages 25 to 65 years
- Conditions the study is for
- Obesity, Morbid, Weight Regain After Bariatric Surgery, Insufficient Weight Loss After Bariatric Surgery
- What is being tested?
- Revisional bariatric surgery
- Type of treatment
- Surgery or procedure
- How many people
- 96 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2017to 30 Sep 2026
- 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 25 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults aged 25 to 65 years who underwent revisional bariatric surgery in the Department of General Surgery between 2017 and 2025 after one or more previous bariatric operations, identified from the centre's follow-up records.
Who may be able to join
- Age 25 to 65 years.
- One or more previous bariatric operations.
- Revisional bariatric surgery performed at the study centre between 2017 and 2025.
- Revision performed for at least one of the following:
- Insufficient weight loss: %EWL below 50% or BMI above 35 kg/m2 at least 18 months after the primary operation.
- Weight regain: BMI rising to 35 kg/m2 or more after successful weight loss, a gain of more than 10 kg from the lowest weight, or an increase of 5 kg/m2 from the lowest BMI.
- Recurrence of obesity-related comorbidities.
- Complications of the primary operation requiring revision.
Who cannot join
- Uncontrolled psychiatric illness.
- Substance abuse.
- Severe hepatic or renal dysfunction.
- Non-compliance with long-term follow-up.
About this study
Official title: Outcomes of Revisional Bariatric Surgery for Insufficient Weight Loss, Weight Regain, Recurrent Comorbidities or Complications of the Primary Operation: A Retrospective Single-Centre Cohort Study
Some people who have had weight-loss (bariatric) surgery do not lose enough weight, regain much of the weight they lost, see obesity-related diseases such as diabetes or high blood pressure return, or develop complications of the first operation. Many of them need a second, revisional operation.
This study reviews the medical records of adults who had revisional bariatric surgery between 2017 and 2025 at a single surgical centre. It describes which revisional operations were performed after each type of first operation and measures how much weight patients lost 6 months, 12 months and up to 3 years after the revision. It also records whether obesity-related diseases and quality of life improved after the revision, and looks at patient factors linked to better weight loss.
Read the detailed description
Background Revisional bariatric surgery is performed when a primary bariatric operation results in insufficient weight loss or weight regain, when obesity-related comorbidities recur, or when complications of the primary operation require revision. The choice of revisional procedure depends largely on the primary operation, and outcome data across the range of primary and revisional procedures remain limited.
Design and setting Retrospective, single-centre, observational cohort study of patients who underwent revisional bariatric surgery in the Department of General Surgery between 2017 and 2025. Data are extracted from the centre's follow-up records. The study was approved by the scientific committee of the Department of General Surgery and the institutional research ethics committee, and is reported according to the STROBE guideline.
Data collected Age, sex and height; the primary bariatric procedure and its year; reflux (GERD) symptoms before and after the primary operation; complications of the primary operation; weight before the primary operation, the lowest weight reached after it and the weight before revision; the interval from the primary operation to weight rebound; satisfaction with weight loss after the primary operation; the revisional procedure and its date; weights at 6 months, 12 months and 3 years after revision; obesity-related comorbidities and their outcome after revision; and quality of life after revision.
Revisional procedures Roux-en-Y gastric bypass (RYGB), banded RYGB, one-anastomosis gastric bypass (OAGB), single-anastomosis duodeno-ileal bypass (SADI), SADI with sleeve gastrectomy (SADI-S), re-sleeve or conversion to sleeve gastrectomy (LSG), distalisation of a bypass, and reversal of the primary operation.
Definitions BMI = weight (kg) / height (m) squared. Weight regain = weight before revision minus the lowest weight after the primary operation. Total weight loss: %TWL = (weight before revision - follow-up weight) / weight before revision x 100. Excess weight loss: %EWL = (weight before revision - follow-up weight) / (weight before revision - weight at BMI 25 kg/m2) x 100, calculated only for patients with a recorded height. A successful result is defined as %EWL of 50% or more.
Data management Source data are cleaned before analysis (date conversion, standardisation of free text, checking of implausible values). Missing values are not imputed; each analysis is a complete-case analysis and the number of patients analysed is reported for every result.
Statistical analysis SPSS 27 and Python 3 (SciPy). Categorical variables as n (%) with Wilson 95% confidence intervals for the main proportions; continuous variables as mean +/- SD or median (IQR), with normality assessed by the Shapiro-Wilk test. Paired weights are compared with the paired t test and Wilcoxon signed-rank test (Cohen's d for paired samples); weights at the four time points with the Friedman test followed by pairwise Wilcoxon tests with Bonferroni correction. Independent groups are compared with the Mann-Whitney U or Kruskal-Wallis test; paired proportions with the exact McNemar test; unpaired proportions with Fisher's exact test or a permutation chi-square test. Associations are assessed with Spearman correlation, and a multiple linear regression examines factors associated with %TWL at 12 months after conversion procedures (age, sex, weight before revision, years from primary operation to revision, and LSG versus bypass-type revision). Reversal and distalisation operations are excluded from group comparisons and the regression. Tests are two-sided with p < 0.05 considered significant; comparisons between revisional procedures are exploratory. The protocol sample-size calculation (alpha 0.05, power 80%) targeted 164 patients.
- Conditions
- Obesity, Morbid, Weight Regain After Bariatric Surgery, Insufficient Weight Loss After Bariatric Surgery, Complication of Bariatric Surgery, Weight Loss, Comorbidities and Coexisting Conditions
- Being tested
- Revisional bariatric surgery
- Keywords
- Revisional bariatric surgery, Conversional bariatric surgery, Weight regain, Roux-en-Y gastric bypass, One-anastomosis gastric bypass, SADI-S, Sleeve gastrectomy, Vertical banded gastroplasty, Adjustable gastric band, Total weight loss
- Medical subject headings
- Obesity, Morbid, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Revisional bariatric surgeryProcedure or surgery
Revisional or conversional bariatric operation after a previous bariatric procedure, as chosen by the treating team: Roux-en-Y gastric bypass (RYGB), banded RYGB, one-anastomosis gastric bypass (OAGB), single-anastomosis duodeno-ileal bypass (SADI), SADI with sleeve gastrectomy (SADI-S), re-sleeve or conversion to sleeve gastrectomy, distalisation of a bypass, or reversal of the primary operation.
| Study group | Role | What they receive |
|---|---|---|
| Revisional bariatric surgery cohort | Adults aged 25 to 65 years who underwent revisional bariatric surgery between 2017 and 2025 after one or more previous bariatric operations, for insufficient weight loss, weight regain, recurrence of comorbidities or complications of the primary operation. Receives: Procedure: Revisional bariatric surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Total Weight Loss (%TWL) After Revisional Bariatric Surgery
Weight loss after revision expressed as the percentage of total weight loss (%TWL), calculated as: %TWL = [(body weight before revision - body weight at follow-up) / body weight before revision] x 100. Body weight is measured in kilograms (kg) on a clinic weighing scale before revision and at each follow-up visit, and recorded in the patient's follow-up file. Unit of measure: percentage (%) of pre-revision body weight.
Measured: 6 months, 12 months and 3 years after revisional surgery
Percentage of Excess Weight Loss (%EWL) After Revisional Bariatric Surgery
Weight loss after revision expressed as the percentage of excess weight loss (%EWL), calculated as: %EWL = [(body weight before revision - body weight at follow-up) / (body weight before revision - ideal body weight)] x 100, where ideal body weight is the weight corresponding to a body mass index (BMI) of 25 kg/m2 for the patient's height. Body weight is measured in kilograms (kg) on a clinic weighing scale and height in metres (m); both are recorded in the patient's follow-up file. Unit of measure: percentage (%) of excess body weight.
Measured: 6 months, 12 months and 3 years after revisional surgery
Secondary outcomes (3)
Percentage of Patients With Improvement of Obesity-Related Comorbidities After Revisional Surgery
Among patients with at least one obesity-related comorbidity before revision (such as hypertension, type 2 diabetes mellitus, dyslipidaemia or asthma), the percentage whose comorbidity improved after revision. Each comorbidity is assessed clinically by the treating surgical team at follow-up and recorded in the patient's follow-up file as "improved" or "not improved". Unit of measure: percentage (%) of patients.
Measured: Up to 3 years after revisional surgery
Percentage of Patients Reporting Improved Quality of Life After Revisional Surgery
Patient-reported overall quality of life after revision compared with before revision. At follow-up, patients are asked whether their overall quality of life has improved after the revisional operation, and the answer is recorded in the patient's follow-up file as "improved" or "not improved". No validated quality-of-life questionnaire is used. Unit of measure: percentage (%) of patients.
Measured: Up to 3 years after revisional surgery
Number of Patients With Complications of Revisional Surgery
Number of patients with any intraoperative or postoperative complication related to the revisional operation, as documented by the treating surgical team in the patient's medical and follow-up records. Unit of measure: number of patients.
Measured: From the day of revisional surgery up to 3 years after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2026
- Study start1 Jan 2017
- Primary completion1 Apr 2025
- Study completion30 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity, MorbidStudies 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
- 96 participants (actual)
Sponsor and investigators
- Lead sponsor
- Kasr El Aini Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ahmed Abdelsalam M, Kasr El Aini Hospital
- Investigators
- Ahmed Abdelsalam, MD, Principal investigator, Cairo University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07880691
- Sponsor's protocol ID
- RevBariatric-Cohort-2017-2025
- Status last verified
- Oct 2026
- First submitted
- 8 Oct 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared; aggregate results are reported in the publication.
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Outcomes of Revisional Bariatric Surgery for Insufficient Weight Loss, Weight Regain, Recurrent Comorbidities or Complications of the Primary Operation: A Retrospective Single-Centre Cohort Study
- ClinicalTrials.gov ID
- NCT07880691
- Acronym / sponsor ID
- RevBariatric-Cohort-2017-2025
- Conditions
- Obesity, Morbid, Weight Regain After Bariatric Surgery, Insufficient Weight Loss After Bariatric Surgery, Complication of Bariatric Surgery, Weight Loss, Comorbidities and Coexisting Conditions
- Keywords
- Revisional bariatric surgery, Conversional bariatric surgery, Weight regain, Roux-en-Y gastric bypass, One-anastomosis gastric bypass, SADI-S, Sleeve gastrectomy, Vertical banded gastroplasty
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 96 participants (actual)
- Lead sponsor
- Kasr El Aini HospitalUniversity, hospital or other
- Study start
- 1 Jan 2017 (actual)
- Primary completion
- 1 Apr 2025 (actual)
- Study completion
- 30 Sep 2026 (actual)
- First posted
- 19 Oct 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.
Some people who have had weight-loss (bariatric) surgery do not lose enough weight, regain much of the weight they lost, see obesity-related diseases such as diabetes or high blood pressure return, or develop complications of the first operation. Many of them need a second, revisional operation.
This study reviews the medical records of adults who had revisional bariatric surgery between 2017 and 2025 at a single surgical centre. It describes which revisional operations were performed after each type of first operation and measures how much weight patients lost 6 months, 12 months and up to 3 years after the revision. It also records whether obesity-related diseases and quality of life improved after the revision, and looks at patient factors linked to better weight loss.
Detailed description
Background Revisional bariatric surgery is performed when a primary bariatric operation results in insufficient weight loss or weight regain, when obesity-related comorbidities recur, or when complications of the primary operation require revision. The choice of revisional procedure depends largely on the primary operation, and outcome data across the range of primary and revisional procedures remain limited.
Design and setting Retrospective, single-centre, observational cohort study of patients who underwent revisional bariatric surgery in the Department of General Surgery between 2017 and 2025. Data are extracted from the centre's follow-up records. The study was approved by the scientific committee of the Department of General Surgery and the institutional research ethics committee, and is reported according to the STROBE guideline.
Data collected Age, sex and height; the primary bariatric procedure and its year; reflux (GERD) symptoms before and after the primary operation; complications of the primary operation; weight before the primary operation, the lowest weight reached after it and the weight before revision; the interval from the primary operation to weight rebound; satisfaction with weight loss after the primary operation; the revisional procedure and its date; weights at 6 months, 12 months and 3 years after revision; obesity-related comorbidities and their outcome after revision; and quality of life after revision.
Revisional procedures Roux-en-Y gastric bypass (RYGB), banded RYGB, one-anastomosis gastric bypass (OAGB), single-anastomosis duodeno-ileal bypass (SADI), SADI with sleeve gastrectomy (SADI-S), re-sleeve or conversion to sleeve gastrectomy (LSG), distalisation of a bypass, and reversal of the primary operation.
Definitions BMI = weight (kg) / height (m) squared. Weight regain = weight before revision minus the lowest weight after the primary operation. Total weight loss: %TWL = (weight before revision - follow-up weight) / weight before revision x 100. Excess weight loss: %EWL = (weight before revision - follow-up weight) / (weight before revision - weight at BMI 25 kg/m2) x 100, calculated only for patients with a recorded height. A successful result is defined as %EWL of 50% or more.
Data management Source data are cleaned before analysis (date conversion, standardisation of free text, checking of implausible values). Missing values are not imputed; each analysis is a complete-case analysis and the number of patients analysed is reported for every result.
Statistical analysis SPSS 27 and Python 3 (SciPy). Categorical variables as n (%) with Wilson 95% confidence intervals for the main proportions; continuous variables as mean +/- SD or median (IQR), with normality assessed by the Shapiro-Wilk test. Paired weights are compared with the paired t test and Wilcoxon signed-rank test (Cohen's d for paired samples); weights at the four time points with the Friedman test followed by pairwise Wilcoxon tests with Bonferroni correction. Independent groups are compared with the Mann-Whitney U or Kruskal-Wallis test; paired proportions with the exact McNemar test; unpaired proportions with Fisher's exact test or a permutation chi-square test. Associations are assessed with Spearman correlation, and a multiple linear regression examines factors associated with %TWL at 12 months after conversion procedures (age, sex, weight before revision, years from primary operation to revision, and LSG versus bypass-type revision). Reversal and distalisation operations are excluded from group comparisons and the regression. Tests are two-sided with p < 0.05 considered significant; comparisons between revisional procedures are exploratory. The protocol sample-size calculation (alpha 0.05, power 80%) targeted 164 patients.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Revisional bariatric surgery cohort | – | Procedure: Revisional bariatric surgeryAdults aged 25 to 65 years who underwent revisional bariatric surgery between 2017 and 2025 after one or more previous bariatric operations, for insufficient weight loss, weight regain, recurrence of comorbidities or complications of the primary operation. |
Who may qualify
- Ages
- 25 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults aged 25 to 65 years who underwent revisional bariatric surgery in the Department of General Surgery between 2017 and 2025 after one or more previous bariatric operations, identified from the centre's follow-up records.
Key inclusion criteria (8 listed)
- Age 25 to 65 years.
- One or more previous bariatric operations.
- Revisional bariatric surgery performed at the study centre between 2017 and 2025.
- Revision performed for at least one of the following:
- Insufficient weight loss: %EWL below 50% or BMI above 35 kg/m2 at least 18 months after the primary operation.
Key exclusion criteria (4 listed)
- Uncontrolled psychiatric illness.
- Substance abuse.
- Severe hepatic or renal dysfunction.
- Non-compliance with long-term follow-up.
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 |
|---|---|---|
| Revisional bariatric surgeryRevisional or conversional bariatric operation after a previous bariatric procedure, as chosen by the treating team: Roux-en-Y gastric bypass (RYGB), banded RYGB, one-anastomosis gastric bypass (OAGB), single-anastomosis duodeno-ileal bypass (SADI), SADI with sleeve gastrectomy (SADI-S), re-sleeve or conversion to sleeve gastrectomy, distalisation of a bypass, or reversal of the primary operation. | Procedure or surgery | Revisional bariatric surgery cohort |
Primary outcome
Percentage of Total Weight Loss (%TWL) After Revisional Bariatric Surgery
Time frame: 6 months, 12 months and 3 years after revisional surgery
Weight loss after revision expressed as the percentage of total weight loss (%TWL), calculated as: %TWL = [(body weight before revision - body weight at follow-up) / body weight before revision] x 100. Body weight is measured in kilograms (kg) on a clinic weighing scale before revision and at each follow-up visit, and recorded in the patient's follow-up file. Unit of measure: percentage (%) of pre-revision body weight.
Percentage of Excess Weight Loss (%EWL) After Revisional Bariatric Surgery
Time frame: 6 months, 12 months and 3 years after revisional surgery
Weight loss after revision expressed as the percentage of excess weight loss (%EWL), calculated as: %EWL = [(body weight before revision - body weight at follow-up) / (body weight before revision - ideal body weight)] x 100, where ideal body weight is the weight corresponding to a body mass index (BMI) of 25 kg/m2 for the patient's height. Body weight is measured in kilograms (kg) on a clinic weighing scale and height in metres (m); both are recorded in the patient's follow-up file. Unit of measure: percentage (%) of excess body weight.
3 secondary outcomes
Percentage of Patients With Improvement of Obesity-Related Comorbidities After Revisional Surgery
Time frame: Up to 3 years after revisional surgery
Percentage of Patients Reporting Improved Quality of Life After Revisional Surgery
Time frame: Up to 3 years after revisional surgery
Number of Patients With Complications of Revisional Surgery
Time frame: From the day of revisional surgery up to 3 years after surgery
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 19 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared; aggregate results are reported in the publication.
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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.
Ahmed Abdelsalam, MD principal investigator
Cairo University
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity, Morbid and Weight Regain After Bariatric Surgery, run by Kasr El Aini Hospital.
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 8 inclusion and 4 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 19 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
Percentage of Total Weight Loss (%TWL) After Revisional Bariatric Surgery (time frame: 6 months, 12 months and 3 years after revisional surgery). The study lists 2 primary outcomes in all. 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 19 Oct 2026.