Influence of the catheter diameter on the investigation of the esophageal motility through solid-state high-resolution manometry.

Past studies have shown that catheter diameter is one of the device-dependent problems which influence the manometric results in the conventional water perfusion esophageal manometry. High-resolution solid-state manometry which abandons water perfusion is thought as an improved manometry method benefited from more pressure sensors, and it is gradually widely used in many present esophageal motility studies. There was no research to evaluate the influence of catheter diameter on the solid-state high-resolution manometry results. The aim of this study was to investigate whether solid-state high-resolution catheters of different diameter provide different data and results. Nine asymptomatic volunteers and 18 gastroesophageal reflux disease patients accepted high-resolution manometry examinations with two solid-state catheters of different outer diameter (4.2 mm and 2.7 mm). Every examination contained 5 minutes resting pressure, 10 water swallows and 10 bread swallows. Some important parameters of the esophageal sphincters and esophageal body peristalsis were analyzed. They included the locations and resting pressure of sphincters, the distal contractile integral, the 4-second integrated relaxation pressure etc. Then, these parameters and the diagnosis of each swallow based on them provided by the two different diameter catheters were compared. (i) The 4.2 mm thick catheter provided higher upper esophageal sphincter resting pressure than the 2.7 mm thick catheter (59.4 ± 21.1 mmHg vs. 49.7 ± 21.4 mmHg); (ii) the 2.7 mm thick catheter provided higher 4-second integrated relaxation pressure than the 4.2 mm thick catheter (10.9 ± 4.5 mmHg vs. 8.5 ± 3.8 mmHg) in water swallows; (iii) the mean distal contractile integral of the water and bread swallows in the large diameter catheter were higher than in the small diameter catheter (989.2 ± 650.0 mmHg/cm/s vs. 806.3 ± 563.7 mmHg/cm/s in water swallows, 1762.5 ± 1440.6 mmHg/cm/s vs. 1275.7 ± 982.0 mmHg/cm/s in bread swallows); (iv) on the lower esophageal sphincter resting pressure, most parameters in bread swallows provided by the two catheters were of no statistical significance; (v) the 2.7 mm thick catheter detected more hypotensive peristalsis swallows than the other catheter in water swallows; and (vi) the final diagnosis of about half of the subjects provided by the two catheters were different. The 2.7 mm thick solid-state high-resolution manometry catheter provides somewhat different data from the usually used 4.2 mm thick catheter. It is needed to set up different and independent series of normative value for the solid-state high-resolution manometry catheters of different outer diameter. The normative value and diagnostic criterion got from one catheter is not universal and acceptable for researches with catheter of different diameter.