Improved lower esophageal sphincter manometry: application of the end-hole recording technique in vivo

The recommendation to use a thin end-hole catheter for lower esophageal (LES) manometry has a strong theoretic background supported by previous in vitro studies. The pressure in the closed sphincter is measured, and the problem of pressure asymmetry eliminated. In this study the advantage and applicability of an end-hole catheter compared with the composite side-hole catheter for LES manometry was tested in vivo in dogs and human subjects. Pull-through manometry was performed with a continuously infused composite four-lumen catheter with one central channel and three side-hole channels enabling simultaneous end-hole and side-hole recording of LES pressure. A pull-through produced one end-hole and three side-hole pressure registrations. The end-hole recorded resting sphincter pressure was 19.7 +/- 4.5 cm H2O in 6 dogs and 9.9 +/- 6.8 cm H2O in 89 human subjects (volunteers and patients). The side holes recorded higher pressures, longer high-pressure zones, and obvious differences--asymmetry--between the three channels. The correlation between the side-hole and end-hole recordings was equally poor with regard to both pressure and length, with r values from 0.48 to 0.61. The relative difference between the end hole and side holes was most pronounced in low-pressure sphincters. In the dogs the end-hole and one side-hole channel always recorded LES pressure close to the expected 0 pressure during reflux, whereas the other two side-hole channels recorded high pressures. The present study proved the applicability of the end-hole technique for LES manometry in vivo in man. The end hole seemed to record true sphincter pressure.