Mechanisms of action of antireflux surgery: theory and fact.

Despite the absence of definitive explanations regarding either the physiologic or surgical factors which curtail gastro-esophageal reflux, effective antireflux operations exist. This article explores the theoretical factors relevant to the surgical control of reflux. These theoretical features include: (1) the pressure, length, and location of the manometrically defined lower esophageal sphincter (LES); (2) the gastro-esophageal valve as defined by the angle of His and a mucosal flap valve; and (3) the mechanical effects of a fundoplication which serve to increase the opening pressure of the cardia and optimize the physical relationships described by the law of La Place. Finally, the relation of these theoretical factors to actual operations is discussed.