Which of the following does not help in the prevention of reflux esophagitis?
Long intraabdominal esophagus
Increased intraabdominal pressure
Right crus of diaphragm
Increased intrathoracic pressure
The principal barrier to reflux is the lower esophageal sphincter. LES comprises the lower 4 cm of esophagus, where resting pressure within the lumen normally exceeds the intragastric pressure. This high intraluminal pressure at LES prevents the GE reflux. The LES is a physiological entity rather than any anatomical structure. Factors contribute to the high intraluminal pressure of LES: Intrinsic musculature of distal esophagus: these muscles differ from those in the other area of the esophagus in that they are in a state of tonic contraction. They normally relax with initiation of the a swallow and then return to a state of tonic contraction. Sling fibres of cardia Crura of the diaphragm Intra Abdominal pressure: the intra abdominal pressure compresses the abdominal segment of the esophagus and is probably the most impoant factor in preventing the reflux. The gastroesophageal angle: the oblique entry of the esophagus has a valvular effect, in that it closes the esophagus when gastric fundus distends. Folds of the mucosa at the cardia : helps in closing the LES when intragastric pressure arises. Intrathoracic pressure has no role in preventing reflux as it is too low ranging from -5 to + 5mm of Hg Ref: Sabiston 18/e, Page 1108 ; Essential of Surgery By Sunil Chumber 1/e, Page 7 ; Textbook of Surgery By S. Das 3/e, Page 790