Leakage = Obstruction & "Dog Ear": A Deterministic Biomechanical Hypothesis for Staple Line Failure After Sleeve Gastrectomy

Background.Staple line leak after sleeve gastrectomy remains one of the least predictable complications in bariatric surgery. Despite numerous proposed explanations, no consensus pathogenetic model exists.Objective.To develop a deterministic biomechanical hypothesis accounting for the mechanism of staple line failure after sleeve gastrectomy.Hypothesis.The present work proposes the formula: Leakage = Obstruction & "Dog Ear". Leak is posited to be the predictable consequence of two co-occurring conditions: (1) mechanical or functional obstruction generating excess intraluminal pressure in the proximal gastric sleeve, and (2) a "dog ear" — a residual triangular pouch at the angle of His acting as a gas-and-fluid trap that prevents pressure decompression into the esophagus. Neither factor alone is sufficient: isolated obstruction results in stenosis; an isolated “dog ear”, in the absence of elevated pressure, remains clinically inconsequential.Conclusion.The formula Leakage = Obstruction & "Dog Ear" offers a reproducible biomechanical framework for understanding and preventing staple line failure after sleeve gastrectomy. Prospective experimental investigation is required.