title: A new ultrasound-guided esophageal variceal pressure-measuring device.
abstract: OBJECTIVE
  To develop a noninvasive method and device to determine intravariceal pressure and variceal wall tension by measuring the variables of the Laplace equation and test this device in a model of esophageal varices.
  
  
  METHODS
  Two variceal pressure measurement devices were constructed. The first device consists of an Olympus 20 MHz ultrasound transducer placed next to a latex balloon catheter attached to a pressure transducer. The second device was constructed by placing the same ultrasound transducer inside a latex condom balloon attached to a pressure transducer. These pressure measurement devices were tested blindly in varix models with different intravariceal pressures, by inflating the balloon to flatten the varix models. Each variceal pressure was measured 10 times by two separate investigators blinded to the actual pressures. The mean intravariceal pressures were calculated. The variceal models were made of a latex balloon filled with water and coffeemate.
  
  
  RESULTS
  The correlation coefficient between the actual and measured varix pressures for both devices was 0.99. The percent error ranged from 0 to 10%. The correlation coefficient between the investigators making the blinded measurements for both devices was 0.98.
  
  
  CONCLUSIONS
  Two pressure-measuring devices were developed to determine intravariceal pressure in a model varix system. These devices demonstrate a low percent error and a high correlation to the actual variceal pressures with low intra- and interobserver variability. These devices have the potential to measure all the variables of the Laplace equation for wall tension. We plan to test these devices in human subjects.
authors.affiliation: Department of Gastroenterology, Temple University Hospital, Philadelphia, Pennsylvania 19140, USA.
authors.forename: Larry S
authors.initials: LS
authors.lastname: Miller
authors.forename: Qing
authors.initials: Q
authors.lastname: Dai
authors.forename: Antonia
authors.initials: A
authors.lastname: Thomas
authors.forename: Chan Y
authors.initials: CY
authors.lastname: Chung
authors.forename: June
authors.initials: J
authors.lastname: Park
authors.forename: Stephanie
authors.initials: S
authors.lastname: Irizarry
authors.forename: Tung
authors.initials: T
authors.lastname: Nguyen
authors.forename: Vinod
authors.initials: V
authors.lastname: Thangada
authors.forename: Elan S
authors.initials: ES
authors.lastname: Miller
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Kim
mesh_terms: D004932:Esophageal and Gastric Varices / Q000503:physiopathology*; D004947:Esophagus / Q000503:physiopathology*; D008365:Manometry / Q000295:instrumentation*; D008954:Models, Biological; D014160:Transducers, Pressure; D018084:Ultrasonography, Interventional