HUMAN GALLBLADDER PRESSURE AND VOLUME - VALIDATION OF A NEW DIRECT METHOD FOR MEASUREMENTS OF GALLBLADDER PRESSURE IN PATIENTS WITH ACUTE CHOLECYSTITIS

Increased gallbladder (GB) pressure is probably a part of the pathogen esis of acute cholecystitis, and measurements of GB pressure might the refore be of interest. The aim of this study was to validate a microti p pressure transducer for intraluminal GB pressure measurements. In vi tro precision and accuracy was within 0.2 mmHg, (SD) and 0.6+/-0.1 mmH g (mean+/-SD), respectively. Pressure rise rate was 24.8+/-5.5 mmHg s( -1). Zero drift was in the range 0.3+/-0.4 to 0.8+/-0.9 mmHg (mean+/-S D). GB pressure was investigated in 16 patients with acute cholecystit is treated with percutaneous ultrasonically guided cholecystostomy. Ba sal intraluminal GB pressure was 8.9 mmHg (2.1-12.2 mmHg; n=9, open cy stic duct) and 1.8 and 5.8 mmHg (n=2, closed cystic duct). There was n o significant difference between two different measurements in the sam e patients (n=5). The pressure was significantly influenced by respira tion (n=8) and the pressure seems to be higher in the sitting position than in the supine position (n=5). Cystic duct opening pressure was 1 0.4, 11.2 and 16.8 mmHg (n=3). Pressure-volume responses showed that t he GB up to a certain volume could accommodate increases in intralumin al volume with only slight changes in intraluminal pressure (n=4). Exc ept for the zero drift, this piece of equipment seemed to fulfil the r equirements of being able to measure pressure in the GB. In vivo measu rements showed a good clinical reproducibility of the method, and also that respiration and patient posture influenced the pressure measurem ents. Further, a GB pressure-volume relationship was demonstrated, and the possibility of a cystic duct opening pressure was described.