Fig. 5.

A and B: relationship between changes in US images, pressure, impedance, and CSA of the circular and longitudinal muscle of the esophagus at 5 cm above the LES in 2 patients with type 3 achalasia esophagus. Note, the onset of luminal distension is associated with drop in impedance, and luminal closure is associated with increase in thickness of circular and longitudinal muscle thickness (CSA). Also note that the muscle thickness is significantly greater in patients compared with normal subjects (Fig. 4, A and B).