The effect of manometric assembly diameter on intraluminal esophageal pressure recording.

Recent studies indicate that lower esophageal sphincter pressure is influenced by manometric assembly diameter. This study determines the effect of assembly diameter on both esophageal sphincter pressure and peristaltic pressure in the esophageal body. We performed esophageal manometric studies in 6 normal subjects using graded assembly diameters. High-fidelity recording was achieved by using a noncompliant catheter-infusion system. The results indicate that increases in assembly diameter cause significant increases in peristaltic pressure amplitudes and in resting sphincter pressure in both the smooth and striated muscle portions of the esophagus. This phenomenon is best explained by the length-tension characteristics of esophageal muscle, increased stretch causing greater contraction force.