Surgery>>>>>The Esophagus and Diaphragmatic Hernia
Question 7#

The most common cause of a deficient LES is:

A. Inadequate overall length
B. Mean resting pressure >6 mm Hg
C. Inadequate intra -abdominal length
D. Failure of receptive relaxation

Correct Answer is C

Comment:

It is important that a portion of the total length of the LES be exposed to the effects of an intra-abdominal pressure. That is, during periods of elevated intra -abdominal pressure, the resistance of the barrier would be overcome if pressure were not applied equally to both the LES and stomach simultaneously. Thus, in the presence of a hiatal hernia, the sphincter resides entirely within the chest cavity and cannot respond to an increase in intra-abdominal pressure because the pinch valve mechanism is lost and gastroesophageal reflux is more liable to occur. Therefore, a permanently defective sphincter is defined by one or more of the following characteristics: An LES with a mean resting pressure ofless than 6 mm Hg, an overall sphincter length of <2 em, and intra-abdominal sphincter length of <1 em. Compared to normal subjects without GERD these values are below the 2.5 percentile for each parameter. The most common cause of a defective sphincter is an inadequate abdominal length.