The purpose of the study is to evaluate the superiority of anterior crural repair during sleeve gastrectomy over no repair in decreasing the incidence of gastroesophageal reflux disease.

Introduction Obesity is a global pandemic. The prevalence of overweight and obesity is increasing globally. Together with its co-morbidities, obesity substantially decreased quality of life and life expectancy. Bariatric surgery has been shown to provide substantial and sustained effects on weight loss and ameliorates obesity-related comorbidities. Among different bariatric procedures, laparoscopic sleeve gastrectomy (LSG) is increasingly being performed due to the favorable bariatric outcome, simplicity of the procedure and relatively low complication profile as compared to bypass procedure.

Development of gastroesophageal reflux disease (GERD is a major health concern after LSG. It has been observed in the bariatric surgical community that many patients are complaining of persisted GERD symptoms after LSG surgery.

Aiming to avoid post-operative GERD, hiatal dissection with crural repair had been suggested to be performed on top of the sleeve gastrectomy procedure.

Data Collection Baseline data collection: All potential candidates will be screened for secondary causes of obesity, such as hypothyroidism and Cushing's syndrome, and are assessed for severity of obesity-related diseases including hypertension, diabetes mellitus, obstructive sleep apnoea syndrome and hyperlipidaemia. Extensive counseling will be given and potential benefits and complications of treatments will be discussed with all participants at least 4 weeks prior to recruitment.

Procedure data: Operative time, blood loss and total hospital stay are captured prospectively. All peri-operative complications will be documented and graded according to the Clavien-Dindo Classification System to facilitate comparison.

Follow-up and assessment:

Patients will be followed up at a designated Multi-disciplinary Clinic of Metabolic and Bariatric Surgery at 4 weeks, 3 months, 6 months, 9 months and 1 year after the operation. A standard dietary and exercise regimen will be prescribed to the patients, and their compliance to the life-style modification is monitored by designated dietitians. Counselling will be provided whenever necessary.

They are assessed for symptomatology according to a standard checklist by independent assessors who are blind to the mode of surgery performed. Data collection and blood tests, endoscopy and esophageal function test (see below) will be carried out during clinic visits.

Adherence to Good Clinical Practices (GCPs) This trial will reference the international ethical principles endorsed by the World Medical Association Declaration of Helsinki as well as ICH/GCP Standards, and any other applicable local laws or regulations

Data Completion and Record Keeping The hard-copy of patients' medical records will be kept in the Prince of Wales Hospital and the electronic information regarding patient information will be stored in the University/Hospital computer and password encrypted. Only the principle investigator, co-investigator and the research nurse will have the right to access these data. Data will be stored for 5 years and after completion of study, both hard & soft copy of the patients & study data will be destroyed and deleted of a body function or damage to a body structure.

Inclusion Criteria:

1. Subject without previous bariatric procedure and meets IFSO Asia-Pacific Chapter Consensus of Metabolic & Bariatric surgery criteria:

   i. BMI more than 35 kg/m2 with or without co-morbidities. ii. BMI more than 30 kg/m2 with obesity related co-morbidities.

2. Subject without evidence of gastroesophageal reflux disease i. Symptomatic - No gastroesophageal reflux symptom (GerdQ score no greater than 7) ii. Endoscopic - No esophagitis. No Hiatus Hernia (apparent separation distance between the squamocolumnar junction and the diaphragmatic impression greater than 2 cm) iii. Functional

1. High-resolution manometry 2. 24-hour esophageal pH study 4. ASA Class I - III 5. Subject is willing to give consent and comply with evaluation and treatment scheduled

Exclusion Criteria:

1. Pre-existing GERD, evident symptomatically, endoscopically or upon functional testing
2. Presence of Hiatus hernia (>2cm) or esophagitis
3. Previous upper GI surgery (e.g. bariatric surgery, anti-reflux surgery; gastrectomy; esophageal surgery)
4. Underlying uncontrolled endocrine problem that lead to obesity. (e.g. Hypothyroidism, Cushing syndrome, eating disorder etc)
5. ASA grade IV & V
6. Mental or psychiatric disorder; Drug or alcohol addiction
7. Cirrhosis or portal hypertension
8. Pregnant or breast feeding
9. Any condition which precludes compliance with the study;
10. History or presence of pre-existing autoimmune connective tissue disease
11. Active malignant disease. Patients with malignant disease who have been disease-free for at least 5 years are eligible
12. Active infection
13. Life expectancy less than 12 months
14. Special population, e.g. prisoner, mentally disabled, investigators' student or employees

The randomization is done by telephone call to the randomization centre where a dedicated research assistant without detailed knowledge of the recruited patient's background will open a sealed envelope containing a computer-generated random number which indicates the mode of intervention. Both the patients and clinical assessors (independent of the operating surgeons) are blind to the mode of intervention in the first one year of enrollment.