Staple Line Suturing in Sleeve Gastrectomy: Its Effect on Resistance to Leakage and Leakage Localization

Introduction: Laparoscopic sleeve gastrectomy (LSG) is currently the most frequently performed bariatric surgery method worldwide. However, it includes the longest staple line (SL), remaining the major source of complications, with leak rates of 0.7% up to 5.7%. Because leaks occur just below the esophagogastric junction in up to 90% of cases, SL reinforcement is widely used, though its effect on failure locations remains insufficiently characterized. Method: This ex vivo study evaluated whether SL reinforcement affects mechanical resistance and leak localization. Sixty human LSG specimens (20/group) from routine resections were randomized to oversewing (Group 1), through-through suturing (Group 2), or no reinforcement (Group 3), using 3/0 polypropylene. Specimens were tested within 40 minutes by intraluminal insufflation via Veres needle and manometer while submerged; burst pressure and leak site were recorded. Results: Baseline characteristics were comparable across groups ( P > .05). Leaks occurred distally in 70% and proximally in 30% of specimens. Reinforcement affected leak topography ( P = .011): Distal leaks predominated in Groups 1 (85%) and 2 (80%), while Group 3 concentrated proximally (55%). Burst pressure differed significantly ( P = .001): Highest with oversewing (mean 116.84 ± 16.35; median 120 110–130 mm Hg), intermediate with through-through sutures (78.52 ± 14.27; median 80 65–90 mm Hg), and lowest without reinforcement (41.00 ± 9.26; median 40 30–50 mm Hg). Conclusion: Oversewing provides the greatest pressure safety window and shifts failure from the high-risk proximal region to distal SL, suggesting reinforcement strategies should anticipate distalized leak patterns, while in vivo validation remains necessary.