Laparoscopic sleeve gastrectomy (LSG) has become an increasingly popular bariatric procedure since its first performance by Hess and Hess in 1988 as a component of the biliopancreatic diversion-duodenal switch (BPD-DS) procedure, which was modified from Scopinaro's biliopancreatic diversion (BPD) and DeMeester's technique. In the early part of the twenty-first century, it was popularized as a first-step intervention before BPD or gastric bypass in the super obese and high-risk group of patients by Regan et al. Due to the unexpected good results in terms of weight loss and resolution of comorbidities, coupled with the simplicity of performing the procedure requiring intervention on only the stomach, sleeve gastrectomy gained status as a stand-alone bariatric procedure as demonstrated by Baltasar et al.
The basic principle of LSG is to create a narrow stomach along the lesser curvature, depending on the left gastric artery, using a calibration bougie as a template to perform a vertical partial gastrectomy, resecting the greater curvature and fundus of the stomach according to the International Sleeve Gastrectomy Expert Panel Consensus Statement by Rosenthal et al. The procedure has demonstrated excellent outcomes in terms of weight loss and comorbidity resolution, making it one of the most commonly performed bariatric procedures worldwide according to the IFSO Worldwide Survey by Angrisani et al.
Bougie Size Considerations and Rationale The selection of an appropriate bougie size during laparoscopic sleeve gastrectomy represents a critical technical decision that significantly influences both immediate surgical outcomes and long-term patient results. Calibration bougies serve as internal templates to standardize the gastric sleeve diameter and ensure consistent sleeve geometry across different surgeons and institutions, as described by Parikh et al.
The diameter of the bougie directly determines the final gastric volume and the degree of restriction achieved, which in turn affects weight loss efficacy, food tolerance, and complication rates.
Bougie sizes in current clinical practice typically range from 32-French (Fr) to 50-Fr, with most centers utilizing sizes between 34-Fr and 42-Fr according to the survey by Gagner et al. Small bougie sizes (32-36-Fr) create a more restrictive sleeve with potentially enhanced weight loss but may be associated with increased risks of stenosis, food intolerance, and gastroesophageal reflux disease as reported by Sakran et al.
Medium bougie sizes (38-42-Fr) represent a compromise between restriction and safety, offering adequate weight loss while maintaining acceptable complication rates as demonstrated by Weiner et al. Large bougie sizes (44-50-Fr) provide greater sleeve capacity with improved food tolerance and potentially reduced leak rates, though concerns exist regarding long-term weight loss maintenance according to Abdallah et al.
The rationale for comparing different bougie sizes stems from the ongoing debate regarding the optimal balance between surgical efficacy and safety. Recent meta-analyses have suggested that larger bougie sizes may be associated with reduced gastric leak rates without significantly compromising weight loss outcomes. However, the majority of existing evidence comes from retrospective observational studies with inherent limitations including selection bias, confounding variables, and lack of standardized outcome measures as noted by Shi et al. The current study aims to provide definitive prospective evidence comparing small (36-Fr) versus X large (larger than 40-Fr) bougie sizes in a randomized controlled trial design.
Furthermore, the impact of bougie size on comorbidity resolution remains inadequately studied. Bariatric surgery has demonstrated remarkable efficacy in resolving obesity-related comorbidities, with diabetes remission rates ranging from 53% to 63% as reported by Schauer et al. and hypertension resolution rates varying from 8% to 50% depending on the specific criteria used according to Sjöström et al. The relationship between sleeve geometry, as determined by bougie size, and comorbidity resolution mechanisms requires further investigation to optimize patient outcomes and surgical technique selection.
Adult patients aged between 18 and 70 years undergoing LSG as a primary bariatric procedure
BMI ≥35 kg/m² regardless of presence, absence, or severity of comorbidities, OR
Type 2 diabetes mellitus
Arterial hypertension
History of previous gastric surgeries or bariatric procedures
American Society of Anesthesiologists (ASA) score >4
Ongoing pregnancy or planned pregnancy within the study period
Los Angeles (LA) Classification Grade B, C, or D reflux esophagitis
Parallel
Bougie (>40-Fr)
Device* Product: MID-TUBE orogastric calibration tube (Médical Innovation Development S.A.S, ref. MID131) * Classification: CE-marked class IIa medical single-use device * Length: 70 cm * Material: Medical silicon rubber, latex-free
Bougie (36-Fr)
Device* Various manufacturers' single-use devices * All devices CE-marked and used per manufacturer instructions * Specific size selection based on center standard care protocols
Gastric Leak Diagnosis and Classification
The diagnosis of gastric leak must be fulfilled with any of the following criteria within 3 months postoperatively according to Benedix et al.: 1. Morphologic examination with contrast studies: * Abdominal CT scan with oral contrast showing extravasation * Upper gastrointestinal swallow studies demonstrating contrast leak * Abnormal perigastric pneumoperitoneum on imaging 2. Surgical evidence: * Direct visualization of staple-line disruption during exploratory re-intervention * Exit of methylene blue dye through drainage during postoperative course * Endoscopic visualization of staple-line defect 3. Endoscopic evidence: * Extravasation of contrast during endoscopy with C-arm fluoroscopy * Direct endoscopic visualization of gastric perforation or staple-line dehiscence Leak Classification System: * Type I (Early): 0-7 days postoperatively * Type II (Intermediate): 8-30 days postoperatively * Type III (Late): \>30 days postoperatively
Quality of Life Assessment - Moorehead-Ardelt Quality of Life Questionnaire II (MA-II)
This validated instrument specifically designed for bariatric surgery patients evaluates six domains of quality of life: 1. Self-Esteem: Assessment of patient's self-perception and confidence levels 2. Physical Activity: Evaluation of exercise capacity and physical function 3. Social Contacts: Assessment of social interactions and relationships 4. Work Performance: Evaluation of occupational capacity and productivity 5. Sexual Interest: Assessment of sexual function and interest 6. Eating Behavior: Evaluation of eating patterns and food-related behaviors Each domain is scored from -3 to +3 points, with total MA-II Score Range: -18 to +18 points. Score interpretation: * Very poor quality of life: -18 to -9 points * Poor quality of life: -8 to -3 points * Fair quality of life: -2 to +2 points * Good quality of life: +3 to +8 points * Very good quality of life: +9 to +18 points
Food Tolerance Assessment - Suter Questionnaire
The questionnaire evaluates: 1. Overall Satisfaction with Food Intake (0-3 points): * 0 = Cannot eat normal food * 1 = Eats small amounts of normal food * 2 = Eats normal food with some restrictions * 3 = Eats normal food without restrictions 2. Food Tolerance Score (0-24 points): Assessment of tolerance to 8 food categories: * Meat * Salad/raw vegetables * Fresh fruits * Bread * Rice/pasta * Vegetables * Dairy products * Liquids Each food scored 0-3 points: * 0 = Cannot eat at all * 1 = Can eat small amounts with difficulty * 2 = Can eat moderate amounts with some difficulty * 3 = Can eat normal amounts without difficulty 3. Eating Behavior Assessment: * Eating frequency per day * Time required for meals * Chewing adequacy * Presence of food aversion Total Suter Score Range: 0-27 points * Excellent tolerance: 24-27 points * Good tolerance: 21-23 points * Fair tolerance: 18-20 points * Poor tolerance: \<18 points
Weight Loss Assessment - Total Weight Loss Percentage (%TWL)
Calculation Formula: %TWL = \[(Initial weight - Current weight) / Initial weight\] × 100 (weight is measured in kilograms Kg) Success Criteria according to Eisenberg et al.: * Adequate weight loss: ≥20% TWL at 12 months * Good weight loss: ≥25% TWL at 12 months * Excellent weight loss: ≥30% TWL at 12 months
Postoperative Nausea and Vomiting Assessment
Assessment Tool: Modified Postoperative Nausea and Vomiting (PONV) Scale according to Apfel et al. Nausea Assessment (0-10 scale): * 0 = No nausea * 1-3 = Mild nausea * 4-6 = Moderate nausea * 7-10 = Severe nausea Vomiting Assessment: * Number of vomiting episodes per 24-hour period * Volume of vomitus (estimated) (Volume is measured in milliliters mL) * Character of vomitus (bilious, food particles, blood) Antiemetic Usage: * Antiemetic administered * Dosage and frequency * Time to administration * Effectiveness assessment
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