Sleeve surgery showdown: does tube size matter for weight loss?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Adult patients aged between 18 and 70 years undergoing LSG as a primary bariatric procedure 2. Body mass index (BMI) criteria according to 2022 ASMBS/IFSO guidelines: * BMI ≥35 kg/m² regardless of presence, absence, or severity of comorbidities, OR * BMI 30-34.9 kg/m² (Class I obesity) with metabolic disease and inadequate response to nonsurgical methods, including: * Type 2 diabetes mellitus * Arterial hypertension * Dyslipidemia * Obstructive sleep apnea syndrome and other severe respiratory disorders * Cardiovascular disease (coronary artery disease, heart failure, atrial fibrillation) * Asthma * Fatty liver disease and nonalcoholic steatohepatitis * Chronic kidney disease * Polycystic ovarian syndrome * Infertility * Pseudotumor cerebri * Bone and joint diseases 3. Decision for bariatric surgery approved after multidisciplinary team discussion 4. Written informed consent obtained 5. Ability to complete questionnaires and attend follow-up visits 6. Stable weight (±5% for 3 months before surgery) 7. Normal preoperative upper gastrointestinal endoscopy or findings limited to: * Los Angeles (LA) Classification Grade A reflux esophagitis (minimal mucosal breaks \<5mm) * Mild gastritis without active ulceration 8. Negative or minimal gastroesophageal reflux symptoms (GERD-Q score ≤8) Exclusion Criteria: 1. History of previous gastric surgeries or bariatric procedures 2. American Society of Anesthesiologists (ASA) score \>4 3. Ongoing pregnancy or planned pregnancy within the study period 4. Significant esophageal and gastric pathology, including: * Los Angeles (LA) Classification Grade B, C, or D reflux esophagitis * Hiatal hernia or any paraesophageal hernia * Barrett's esophagus of any length * Active peptic ulcer disease * Gastric polyps \>1cm or suspicious lesions 5. Severe gastroesophageal reflux disease is defined as: * GERD-Q score \>8 * Daily proton pump inhibitor (PPI) dependency with breakthrough symptoms * Endoscopic evidence of LA Grade B, C, or D esophagitis 6. Coagulation disorders or anticoagulation therapy that cannot be safely discontinued 7. Known silicon hypersensitivity or allergies to bougie materials 8. Active substance abuse or psychiatric conditions that may impair compliance