COMPUTERIZED THERMISTOR TECHNIQUE FOR INDIRECT STUDIES OF ESOPHAGEAL BLOOD-FLOW

The aim of this study was to elaborate on a computerized microthermist or technique for indirect measurement of esophageal blood flow and to investigate if any changes in circulation could be found in patients w ho are provoked by esophageal acid perfusion of their acid-sensitive m ucosa. A thermistor was mounted in a plastic catheter and placed in th e esophagus 11 cm above the lower esophageal sphincter. The signal fro m the thermistor was transmitted to a personal computer. A 15 degrees C water bolus was injected into the catheter in order to cool the esop hageal wall at the catheter side hole 1 cm above the thermistor. The r eliability of the thermistor test was examined by repeating it in 29 p atients. No statistical difference between the two test occasions was found. Twenty-five patients were provoked with an acid perfusion test, 14 of whom had a positive reaction with heartburn, Patients with a po sitive acid perfusion test had a shorter rewarming time before as well as after provocation than patients with a negative acid perfusion tes t. It is concluded that this thermistor technique is well suited for m easuring intraluminal rewarming rate as an indirect sign of changes in esophageal blood flow. Furthermore, the results indicate that blood s upply of the esophageal wall is increased in patients with a positive acid perfusion test.