Bougie Diameter on Outcomes in Laparoscopic Sleeve Gastrectomy

Impact of Bougie Diameter on Outcomes in Laparoscopic Sleeve Gastrectomy - A Randomized Controlled Trial

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.

Hypothesis

The investigators hypothesize that the use of a larger calibration bougie (> 40-Fr) during laparoscopic sleeve gastrectomy will significantly reduce the incidence of postoperative gastric leak compared to standard smaller bougie sizes (36-Fr), without compromising weight loss outcomes or quality of life measures.

Hypotheses Tools

1. Quality of Life Hypothesis: Patients undergoing LSG with > 40-Fr bougie will demonstrate equivalent or superior quality of life outcomes as measured by the Moorehead-Ardelt Quality of Life Questionnaire II (MA-II) compared to those with smaller bougie sizes at 1-month, 6-months and 1-year follow-up.
2. Nutritional Tolerance Hypothesis: Larger bougie diameter (> 40-Fr) will result in improved food tolerance as assessed by the Suter et al. food tolerance questionnaire, leading to better nutritional outcomes and reduced gastrointestinal symptoms.
3. Weight Loss Hypothesis: Despite the larger gastric remnant created by the > 40-Fr bougie, total weight loss percentage (%TWL) at 6 months and 1 year will be non-inferior to that achieved with smaller bougie sizes, with the primary endpoint being ≥20% TWL at 1 year.
4. Complication Hypothesis: The use of >40-Fr bougie will be associated with a lower overall complication rate as classified by the Clavien-Dindo classification system, particularly for grades III-V complications requiring surgical intervention or resulting in life-threatening consequences.
5. Recovery Hypothesis: Patients in the >40-Fr bougie group will experience reduced postoperative pain as measured by Visual Analog Scale (VAS) scores and shorter hospital length of stay compared to the control group.
6. Upper Gastrointestinal Hypothesis: Upper gastrointestinal evaluation at 1 year will demonstrate equivalent or improved anatomical and functional outcomes in the >40-Fr group, with reduced incidence of strictures, gastroesophageal reflux disease, and other upper GI complications.

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