Reversal of Roux-en-Y Gastric Bypass: A Swedish National Cohort 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.

Study Overview

• Status: Active, not recruiting
• Conditions: Revisional Bariatric Surgery; Gastric Bypass Surgery; Complications After Bariatric Surgery

• Study Type: Observational
• Enrollment (Actual): 199

Contacts and Locations

Study Locations

• Sweden
  • Norrköping, Sweden, 60182
    • Vrinnevi Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

National registry-based cohort

Description

Inclusion Criteria:

• Adult patients (≥ 18years) who underwent reversal of RYGB between 2007 and 2023.

Exclusion Criteria:

• 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)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

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 the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Through study completion, an average of 2 years.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Indications for surgery	Indications are categorized as abdominal pain, malnutrition, gastrointestinal symptoms, post-bariatric hypoglycemia, and psychological distress, and reported as number (frequencies).	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.	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).	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).	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.	Through study completion, an average of 2 years.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surgical technique	Surgical approach (laparoscopic or open procedure); Handling of the Roux limb (resection or reconnection); Jejuno-jejunostomy technique (stapled/handsewn); Pyloroplasty/pyloromyotomy (yes/no); Gastro-gastrostomy technique (stapled/handsewn); Blood loss during surgery (ml); Operation time (minutes) -all data presented as number (frequencies)	Perioperative/periprocedural

Collaborators and Investigators

• Sponsor: Vrinnevi Hospital
• Investigators: Principal Investigator: Ellen A Andersson, MD, Department of Surgery, Vrinnevi Hospital, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2025
• Primary Completion (Estimated): March 31, 2026
• Study Completion (Estimated): May 31, 2026

Study Registration Dates

• First Submitted: December 16, 2025
• First Submitted That Met QC Criteria: January 7, 2026
• First Posted (Estimated): January 16, 2026

Study Record Updates

• Last Update Posted (Actual): January 20, 2026
• Last Update Submitted That Met QC Criteria: January 15, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Outcomes; Complications; Roux-en-Y gastric bypass; Anatomical reversal; Indications
• Other Study ID Numbers: Dnr 2022-01827-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Since reversal of RYGB is a rare procedure the risk of identifying individual patients is considerable even if data are pseudonymized.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No