TSBL-Based Versus BMI-Based Biliopancreatic Limb Length in One-Anastomosis Gastric Bypass

NCT07796503 | Recruiting

• 1 other identifier: TSBL-BMI-OAGB
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This study compares two surgical techniques used during one-anastomosis gastric bypass (OAGB) surgery for patients with severe obesity. During this operation, surgeons create a bypass of part of the small intestine, and the length of this bypassed segment (called the biliopancreatic limb) affects both weight loss and the risk of nutritional side effects. In this trial, one group of patients has the limb length calculated individually based on the measured total length of their small intestine (TSBL-based method), while the other group receives a limb length based on standard body mass index (BMI) categories (BMI-based method). The study compares weight loss outcomes, improvement of obesity-related health problems, and complication rates between the two approaches over 12 months after surgery. The trial is being conducted at a single center in Almaty, Kazakhstan, and plans to enroll 100 patients total; this record reflects an interim analysis based on the first 75 patients enrolled.

Conditions

Morbid Obesity; Obesity

Keywords

One Anastomosis Gastric Bypass; Biliopancreatic Limb Length; Bariatric Surgery; Total Small Bowel Length; Weight Loss

Outcome Measures

Primary Outcomes (1)

• Percentage of Excess Weight Loss (%EWL)

  EWL defined as the proportion of weight loss relative to excess baseline weight, with ideal body weight defined as BMI 25 kg/m². Assessed longitudinally over time using linear mixed models.

  Baseline, 3 months, 6 months, and 12 months post-surgery

Secondary Outcomes (5)

• Percentage of Total Weight Loss (%TWL)

  Baseline, 3 months, 6 months, and 12 months post-surgery

• BMI Change

  Baseline, 3 months, 6 months, and 12 months post-surgery

• BMI Loss (BMIL)

  Baseline, 3 months, 6 months, and 12 months post-surgery

• Improvement in Obesity-Related Comorbidities

  12 months post-surgery

• Postoperative Complications

  12 months post-surgery

Study Arms (2)

TSBL-Based Group

EXPERIMENTAL

Biliopancreatic limb length (BPL) individualized based on intraoperatively measured total small bowel length (TSBL), calculated as BPL = 0.35 × TSBL.

Procedure: TSBL-based biliopancreatic limb length determination

BMI-Based Group

ACTIVE COMPARATOR

Biliopancreatic limb length (BPL) determined using standard fixed lengths based on BMI category: 150 cm for BMI 35-39.9, 180 cm for BMI 40-49.9, 200 cm for BMI ≥50.

Procedure: BMI-based biliopancreatic limb length determination

Interventions

TSBL-based biliopancreatic limb length determination PROCEDURE

Biliopancreatic limb length individualized intraoperatively based on measured total small bowel length (TSBL), calculated as BPL = 0.35 × TSBL, prior to laparoscopic one-anastomosis gastric bypass.

TSBL-Based Group

BMI-based biliopancreatic limb length determination PROCEDURE

Biliopancreatic limb length determined using standard fixed lengths based on preoperative BMI category (150 cm, 180 cm, or 200 cm), prior to laparoscopic one-anastomosis gastric bypass.

BMI-Based Group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 65 years
• BMI ≥35 kg/m² in non-Asian populations or ≥32.5 kg/m² in Asian populations
• Presence or absence of metabolic comorbidities (including type 2 diabetes, hypertension, and dyslipidaemia)
• Eligibility for primary one-anastomosis gastric bypass (OAGB)
• Provision of written informed consent

You may not qualify if:

• BMI below the defined thresholds
• Severe decompensated cardiac, pulmonary, hepatic, or renal disease
• Acute inflammatory conditions
• Active gastric or duodenal ulcer
• Psychiatric disorders or substance abuse
• Pregnancy or breastfeeding
• Active malignancy
• Severe intra-abdominal adhesions due to prior surgery
• Secondary obesity related to hypothalamic-pituitary-adrenal axis disorders

Sponsors & Collaborators

• Klaipėda University: collaborator
• Kazakh Medical University "Higher School of Public Health": collaborator
• National Scientific Center of Surgery named after A.N.Syzganov: lead

Study Sites (1)

JSC "National Scientific Center of Surgery named after A.N. Syzganov"

Almaty, Kazakhstan

RECRUITING

MeSH Terms

Conditions

Obesity, Morbid; Obesity; Weight Loss

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Body Weight Changes

Central Study Contacts

Nurbol Orynbassar

CONTACT

+77474528797; nurbolorynbassar@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 27, 2026
• First Posted: September 1, 2026
• Study Start: October 1, 2023
• Primary Completion (Estimated): November 1, 2027
• Study Completion (Estimated): November 1, 2027
• Last Updated: September 1, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Data will be available beginning 3 months after article publication, with no defined end date, for researchers who provide a methodologically sound proposal.
• Access Criteria: Data will be available to researchers who provide a methodologically sound proposal, upon reasonable request to the corresponding author (Nurbol Orynbassar, nurbolorynbassar@gmail.com).

Locations

KA (1)