Bariatric surgery has become one of the most effective treatments for morbid obesity and its associated comorbidities such as type 2 diabetes, hypertension, and obstructive sleep apnea. Among the different procedures, the Laparoscopic Mini Gastric Bypass (MGB), also known as One Anastomosis Gastric Bypass (OAGB), has gained popularity due to its simplicity, safety, and efficacy. In this lecture, Dr. R. K. Mishra demonstrates the step-by-step laparoscopic technique for performing this procedure.

Patient Selection and Preoperative Preparation

Patient selection is crucial for achieving optimal outcomes. Candidates include individuals with:

Body Mass Index (BMI) above 40 kg/m², or above 35 with obesity-related comorbidities.

Those who have failed conservative management such as diet and exercise.

Preoperative steps include:

Complete history and physical examination.

Laboratory work-up, including blood sugar, lipid profile, and liver function tests.

Endoscopy to rule out gastric ulcers or malignancy.

Anesthesia assessment and counseling about dietary modifications post-surgery.

Patients are placed on a high-protein, low-carbohydrate diet for one to two weeks before surgery to reduce liver size and improve laparoscopic access.

Patient Positioning and Port Placement

The patient is positioned in supine, steep reverse Trendelenburg to allow gravitational retraction of the small bowel.

General anesthesia with endotracheal intubation is given.

A five-port technique is usually employed:

One 10 mm camera port supra-umbilical.

Two 12 mm working ports on the left and right sides.

Two 5 mm ports for retraction and assistance.

A liver retractor is introduced through the epigastric port to lift the left lobe of the liver, providing exposure of the esophagogastric junction and proximal stomach.

Creation of the Gastric Tube

The first key step is to fashion a long, narrow gastric tube along the lesser curvature:

Using an endoscopic linear stapler, the stomach is divided starting from the antrum, about 2–3 cm proximal to the pylorus.

Multiple stapler firings are applied vertically towards the angle of His, just below the esophagogastric junction.

The result is a narrow gastric pouch resembling a tube, with a capacity of about 50–150 ml.

This tubular pouch restricts the amount of food intake while maintaining a smooth passage of ingested material.

Identification of the Jejunal Loop

The small intestine is measured approximately 180–200 cm from the ligament of Treitz.

A suitable loop of jejunum is selected, ensuring adequate length to provide both malabsorptive and metabolic benefits.

The chosen jejunal limb is brought up to the gastric pouch in an antecolic and isoperistaltic fashion.

Gastrojejunostomy Formation

This is the single most important step of Mini Gastric Bypass:

A 2–3 cm opening is created in the lower part of the gastric pouch.

A corresponding enterotomy is made in the jejunal loop.

Using an endoscopic linear stapler, a side-to-side gastrojejunostomy is fashioned.

The stapler entry sites are closed with absorbable sutures to ensure a watertight anastomosis.

The anastomosis must be tension-free, wide enough to allow food passage, and leak-proof to prevent postoperative complications.

Reinforcement and Leak Test

The staple line and anastomosis are reinforced with sutures where necessary.

A methylene blue leak test or air insufflation test is performed through an orogastric tube to check for leaks.

Adequate hemostasis is ensured throughout the procedure.

Closure and Drain Placement

A drain may be placed near the gastrojejunostomy depending on surgeon preference.

All ports are inspected for bleeding, and fascial closure is done for 10–12 mm ports.

The skin is closed with absorbable sutures or staples.

Postoperative Management

Patients are shifted to the recovery unit and closely monitored.

Clear liquids are started after 24 hours, progressing to protein-rich fluids and soft diet gradually.

Early ambulation is encouraged to reduce the risk of thromboembolism.

Multivitamin, iron, calcium, and B12 supplementation are mandatory to prevent nutritional deficiencies.

Outcomes and Benefits

The laparoscopic mini gastric bypass provides both restrictive and malabsorptive effects, leading to substantial and sustained weight loss. Additional benefits include:

Resolution or improvement of type 2 diabetes in 70–80% of patients.

Reduction of hypertension, dyslipidemia, and sleep apnea.

Better quality of life and long-term metabolic benefits.

Compared to Roux-en-Y gastric bypass, MGB is technically simpler, involves only one anastomosis, and is associated with shorter operative time.

Risks and Complications

Although safe, potential risks include:

Anastomotic leak or stricture.

Bile reflux due to the long gastric pouch and single anastomosis.

Nutritional deficiencies with poor compliance.

Internal hernia, though less common than in Roux-en-Y bypass.

Careful surgical technique and long-term patient follow-up are essential to minimize complications.

Conclusion

The Laparoscopic Mini Gastric Bypass is an effective and relatively simple bariatric procedure with excellent weight-loss outcomes and metabolic benefits. Through a meticulous step-by-step approach—creation of a gastric tube, selection of the jejunal loop, and single gastrojejunostomy—surgeons can achieve safe and reproducible results. Dr. R. K. Mishra’s demonstration emphasizes the importance of precision, patient selection, and long-term follow-up, making this procedure a cornerstone in modern bariatric surgery.