Impact of the calibration bougie diametre during laparoscopic sleeve gastrectomy on the rate of postoperative staple-line leak (BOUST): study protocol for a multicentre randomized prospective trial

Background: Laparoscopic sleeve gastrectomy (LSG) has become an increasing bariatric procedure. The basic principle is to create a narrow stomach along the lesser curvature, using a calibration bougie as a template to perform a vertical partial gastrectomy, resetting the greater curvature and fundus of the stomach. The most common postoperative complication is gastric leak from the staple line, observed in approximately 3% of cases, which can result in long and incapacitating treatment The diametre of the bougie used to calibrate the remnant stomach could impact the rate of postoperative gastric leak, a higher diametre being correlated with a lower risk of leak, without lowering long-term weight loss. This is the first randomized trial to compare the outcomes of LSG regarding the use of two different bougie diametres on postoperative gastric leak and mid-term weight loss. Methods: Bougie Sleeve Trial (BOUST) is a superiority single-blinded randomized national trial, involving 17 centres. Participants will be randomized into two groups. LSG will be performed using a 48-Fr diametre calibration bougie in the experimental group and a standard care (34 to 38-Fr diametre) calibration bougie in the control group. Both groups will take part in a 2-year postoperative follow-up to assess postoperative gastric leak rate and weight loss and quality of life evolution. Discussion: This study protocol will allow the investigators to determine if the use of a larger calibration bougie during LSG is associated with lower postoperative gastric leak occurrence without impairing mid-term weight loss and quality of life. The results of this trial will provide important data on patient safety and promote best practice for LSG procedures.