BACKGROUND AND STUDY AIMS
Unavoidable catheter movement during sphincter of Oddi (SO) manometry can produce considerable variations in the basal pressure, due to movement of the recording sidehole. The sleeve sensor is a perfused channel which records the highest pressure point along its length. The aim of the study was to develop and evaluate a prototype sleeve sensor for SO manometry.
MATERIALS AND METHODS
Bench-testing was used to assess the dynamic performance of the sleeve and sidehole assemblies. Recordings were initially made with a standard triple-lumen catheter and then with a purpose-built manometric assembly which had a 15 mm long sleeve sensor.
RESULTS
A perfusion rate of 0.04 ml/min gave the best balance between baseline pressure offset and rise rate. Recordings were attempted in nine patients and successfully achieved in four. The sleeve and sidehole recordings of the maximal basal pressure did not differ significantly (mean +/- SEM, 86.1 +/- 26.5 mmHg vs. 90.1 +/- 21.0 mmHg, P = 0.57, r = 0.998).
CONCLUSIONS
Unnecessarily high perfusion rates are being used for SO manometry. The sleeve sensor has the potential to monitor SO pressure more reliably than the currently used perfused sidehole method and should enhance the safety of prolonged SO manometry.