One-anastomosis Gastric Bypass (OAGB) in Rats
November 10th, 2018
This protocol is for the performance of one-anastomosis gastric bypass (OAGB) on rat. The operator performs a long and tubular-stapled gastric pouch followed by hand-sewn anastomosis. For this model, the operator reproduces the same ratio between biliopancreatic and common limb in humans; therefore, the biliopancreatic limb measures 35 cm.
Morbid obesity is a major health issue in the Western world with an increasing prevalence. Bariatric surgery remains the only long-term effective therapy for it and among all kind of surgeries, one Anastomosis Gastric Bypass, which is more recent procedure appears to be effective and safe. But, several questions remain unsolved.
Especially, about metabolical and long term consequences on the antral gastric mucosa after the surgery. To our knowledge no animal model of one anastomosis gastric bypass has yet been developed. And this could be useful to study, for example, glucose metabolism, neuron de queen modifications are long time consequences on other gastric mucosa.
The model, which is presented in this video has been developed in order to mimic the human procedure. First, the surgeon realizes a long and tubular gastric approach and then bypass 35 cm of small bowel. This length has been decided in order to reproduce the ratio between the biliopancreatic limb and the common limb.
As it is done for human surgery. Use Wistar rats in this protocol. And use a diet and just obesity with at least 12 pro body weeks of high fat diet.
Ensure that the rats are obese at the time of the surgery. With a weight between 600 and 800 grams. Here are presented surgical instruments which are needed for this procedure.
Autoclave all surgical instruments before surgery. Anesthetize the rat with inhalation of 3%isoflurane in air for the indication in the redden box. Then transfer the rat to the warming plate and maintain the anesthesia with the face mask at the same flow rate of 3%Surgical approach is a megion la pareta.
Peritoneum is cut along the linear alba in order to open the peritoneal cavity. Great gastric curve is dissected from the junction between the glandular and non-glandular stomach to the left side of the abdominal fagus. Gastrosplenic are progressively coagulated in order to liberate the great gastric curve to the his angle.
Then the heretal area is exposed by a section of 10 ligaments. Abdominal fagus is dissected while preserving the left gastric artery and vagal nerve. Surgical stapler is applied horizontally at the junction between the glandular and non-glandular stomach to the left side of the gastro oesophageal junction.
After cutting the non-glandular stomach this one is removed. Then a second stapler with a TA-device is applied to the first one. The result is a small and tubular gastric approach with an excluded antrum and body of the stomach.
Duodenojejunal angle is located then the surgeon measures 35 cm to the future antmeradu. Antermere is performed on the antimesic side of the duodenojejunal. Then the operator performs a punctiform gastrectomy And then and intoside gasrodiginal anastomosis with 2 running sutures of isopropolene 7 zero.
The key to success is to realize this anastomosis under magnifying glass and to perform about 7-8 closed extra sutures on each side of the one-anastomosis. The result is an amagalope with a bilo-pancreatic and acommon limb connected to the gastric pouch by this one-astomosis. At the end of the procedure the surgeon replaces the abdominal organs into their physiological positions then close the abdominal wall with running suture of taychron 2-0.
Then there forms a perital infiltration of 1 possn zilochine ado this 1 militers of kilogram then close the skin with running suture of vicryl rapide 4-0 Performs and intrum schoolar injection of 20, 000 units kg of cheap isolene and the epirital performs a sub injection of isotne. 1 month later a significant weight loss is observed in this case the rat lost about 20%of it's pro body weight. It has been demonstrated in previous experiences a significant and sustained weight loss compared to sham surgery.
After sacrifice no repair between the pouch and the excluded stomach has yet been observed. The procedure produces a similar metabolic profile after gastric bypass to that in humans. After around an a round of test is observed as well as a quicker return to basisemia when compared to sham rats.
Furthermore after each test an increase in insulin sensitivity is observed. The main advantage of this model is to mimic closely the human procedure. It is reproducible and has already been performed by several surgeons with a low meticula weight of about 15%The main difficulty of this protocol is the gastroduodenal anastomosis In our experience, the learning curve requires about 10 operations for the surgeon to perform it effectively.
Thank you for your attention.
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Overview
This protocol outlines the performance of one-anastomosis gastric bypass (OAGB) on rats, focusing on the creation of a tubular-stapled gastric pouch and hand-sewn anastomosis. This model aims to replicate the human ratio between biliopancreatic and common limb, specifically measuring the biliopancreatic limb at 35 cm.
Key Study Components
Area of Science
- Neuroscience
- Metabolic Surgery
- Animal Models
Background
- Morbid obesity is a growing health concern.
- Bariatric surgery is a long-term solution for obesity.
- One-anastomosis gastric bypass is a newer, effective surgical option.
- Understanding metabolic consequences post-surgery is crucial.
Purpose of Study
- To develop an animal model for studying OAGB.
- To investigate glucose metabolism post-surgery.
- To explore long-term effects on gastric mucosa.
Methods Used
- Creation of a tubular-stapled gastric pouch.
- Hand-sewn anastomosis technique.
- Measurement of biliopancreatic limb length.
- Comparison with human surgical ratios.
Main Results
- Successful establishment of an OAGB model in rats.
- Reproduction of human-like biliopancreatic limb ratios.
- Potential for future studies on metabolic outcomes.
- Insights into gastric mucosa changes post-surgery.
Conclusions
- The rat model is a valuable tool for studying OAGB.
- Further research is needed on metabolic impacts.
- This model can aid in understanding long-term surgical effects.
Frequently Asked Questions
Executive Industry Relevance
This preclinical model enables mechanistic investigation of bariatric surgery outcomes, supporting target validation and de-risking in metabolic disease therapeutic development. By replicating human surgical anatomy and metabolic responses, it provides a disease-relevant system for preclinical evaluation of interventions targeting obesity-related pathways. The model facilitates longitudinal studies that improve predictive confidence in translational research.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses related to glucose metabolism and insulin sensitivity following anatomical modification.
- Operational Value: Provides a reproducible system for functional target validation of metabolic regulators in obesity.
Screening & Assay Development
- Scientific Value: Generates quantitative metabolic readouts such as weight loss and insulin sensitivity changes for assay benchmarking.
- Operational Value: Supports standardization of surgical and postoperative monitoring procedures across laboratories.
Translational & Preclinical Research
- Scientific Value: Offers a disease-relevant system to study long-term consequences on gastric mucosa and metabolic profiles.
- Operational Value: Enables continuity from discovery through preclinical validation with measurable endpoints like sustained weight loss.
Pipeline & Workflow Integration
The model integrates into the discovery continuum by providing a preclinical platform for hypothesis testing in metabolic surgery, supporting lead identification through phenotypic screening of interventions, and informing preclinical work via measurable physiological outcomes.
- Discovery Biology: Supports hypothesis testing of metabolic pathways affected by gastrointestinal rearrangement.
- Screening: Enables assay readiness through standardized postoperative metabolic measurements.
- Analytics: Provides quantitative dependent variable measurements including weight loss percentage and insulin sensitivity changes.
- Translational Research: Connects to preclinical continuity via sustained metabolic improvements observed one month post-surgery.
- Enterprise Reuse: Establishes a reusable surgical model for evaluating multiple therapeutic candidates in obesity research.
Operational & Enterprise Impact
- Scientific Value: Predictive confidence in target validation through replication of human-like metabolic responses.
- Operational Value: Standardization and reproducibility of surgical procedure across operators after initial learning curve.
- Strategic Value: Improved go/no-go decisions by reducing mechanistic ambiguity in metabolic intervention studies.
- Portfolio Impact: Risk-adjusted prioritization based on preclinical efficacy and safety signals.
Implementation Considerations
- Required expertise in rodent surgical techniques and microsuturing.
- Instrumentation including surgical staplers, microsutures, and magnification systems.
- Standardization of postoperative care protocols including hydration, antibiotics, and diet reintroduction.
- Adaptation considerations for different rat strains and obesity induction methods.
- Practical limitation: learning curve requires approximately 10 operations for surgical proficiency.
Biopharma FAQs
Chapters in this video
0:00
Title
1:31
Animals and Diets
1:48
Material
2:18
Surgery
2:22
Laparatomy
2:37
Great Curve and Hiatal Dissection
3:34
Gastric Pouch Confection
4:12
One Anastomosis Gastric Bypass
5:31
Closure and Immediate Care
6:06
Post-operative Care
6:30
Representative Results
7:14
Conclusion
