title: Human gallbladder pressure and volume: validation of a new direct method for measurements of gallbladder pressure in patients with acute cholecystitis.
abstract: Increased gallbladder (GB) pressure is probably a part of the pathogenesis of acute cholecystitis, and measurements of GB pressure might therefore be of interest. The aim of this study was to validate a microtip pressure transducer for intraluminal GB pressure measurements. In vitro precision and accuracy was within 0.2 mmHg, (SD) and 0.6 +/- 0.1 mmHg (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 +/- SD). GB pressure was investigated in 16 patients with acute cholecystitis treated with percutaneous ultrasonically guided cholecystostomy. Basal intraluminal GB pressure was 8.9 mmHg (2.1-12.2 mmHg; n = 9, open cystic duct) and 1.8 and 5.8 mmHg (n = 2, closed cystic duct). There was no significant difference between two different measurements in the same patients (n = 5). The pressure was significantly influenced by respiration (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 10.4, 11.2 and 16.8 mmHg (n = 3). Pressure-volume responses showed that the GB up to a certain volume could accommodate increases in intraluminal volume with only slight changes in intraluminal pressure (n = 4). Except for the zero drift, this piece of equipment seemed to fulfil the requirements of being able to measure pressure in the GB. In vivo measurements showed a good clinical reproducibility of the method, and also that respiration and patient posture influenced the pressure measurements. Further, a GB pressure-volume relationship was demonstrated, and the possibility of a cystic duct opening pressure was described.
authors.affiliation: Department of Medical Gastroenterology, Hvidovre Hospital, University of Copenhagen, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Borly
authors.forename: L
authors.initials: L
authors.lastname: Højgaard
authors.forename: S
authors.initials: S
authors.lastname: Grønvall
authors.forename: J G
authors.initials: JG
authors.lastname: Stage
mesh_terms: D000208:Acute Disease; D002764:Cholecystitis / Q000503:physiopathology*; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005336:Fiber Optic Technology; D005704:Gallbladder / Q000473:pathology* / Q000503:physiopathology*; D005762:Gastroenterology / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D011187:Posture; D011312:Pressure; D012119:Respiration; D014159:Transducers