title: Transient elastography with the XL probe rapidly identifies patients with nonhepatic ascites.
abstract: BACKGROUND
  In contrast with other elastographic techniques, ascites is considered an exclusion criterion for assessment of fibrosis stage by transient elastography. However, a normal liver stiffness could rule out hepatic causes of ascites at an early stage. The aim of the present study was to determine whether liver stiffness can be generally determined by transient elastography through an ascites layer, to determine whether the ascites-mediated increase in intra-abdominal pressure affects liver stiffness, and to provide initial data from a pilot cohort of patients with various causes of ascites.
  
  
  RESULTS
  Using the XL probe in an artificial ascites model, we demonstrated (copolymer phantoms surrounded by water) that a transient elastography-generated shear wave allows accurate determination of phantom stiffness up to a water lamella of 20 mm. We next showed in an animal ascites model that increased intra-abdominal pressure does not affect liver stiffness. Liver stiffness was then determined in 24 consecutive patients with ascites due to hepatic (n = 18) or nonhepatic (n = 6) causes. The cause of ascites was eventually clarified using routine clinical, imaging, laboratory, and other tools. Valid (75%) or acceptable (25%) liver stiffness data could be obtained in 23 patients (95.8%) with ascites up to an ascites lamella of 39 mm. The six patients (25%) with nonhepatic causes of ascites (eg, pancreatitis, peritoneal carcinomatosis) had a significantly lower liver stiffness (<8 kPa) as compared with the remaining patients with hepatic ascites (>30 kPa). Mean liver stiffness was 5.4 kPa ± 1.3 versus 66.2 ± 13.3 kPa.
  
  
  CONCLUSIONS
  In conclusion, the presence of ascites and increased intra-abdominal pressure does not alter underlying liver stiffness as determined by transient elastography. We suggest that, using the XL probe, transient elastography can be used first-line to identify patients with nonhepatic ascites at an early stage.
authors.affiliation: Department of Medicine and Center for Alcohol Research, Liver Disease and Nutrition, Salem Medical Center, University of Heidelberg, Heidelberg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Kohlhaas
authors.affiliation: Department of Medicine and Center for Alcohol Research, Liver Disease and Nutrition, Salem Medical Center, University of Heidelberg, Heidelberg, Germany.
authors.forename: Esteban
authors.initials: E
authors.lastname: Durango
authors.affiliation: Department of Medicine and Center for Alcohol Research, Liver Disease and Nutrition, Salem Medical Center, University of Heidelberg, Heidelberg, Germany.
authors.forename: Gunda
authors.initials: G
authors.lastname: Millonig
authors.affiliation: Department of Research and Development, Echosens, Paris, France.
authors.forename: Cecile
authors.initials: C
authors.lastname: Bastard
authors.affiliation: Department of Research and Development, Echosens, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Sandrin
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Golriz
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Arianeb
authors.initials: A
authors.lastname: Mehrabi
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Markus W
authors.initials: MW
authors.lastname: Büchler
authors.affiliation: Department of Medicine and Center for Alcohol Research, Liver Disease and Nutrition, Salem Medical Center, University of Heidelberg, Heidelberg, Germany.
authors.forename: Helmut Karl
authors.initials: HK
authors.lastname: Seitz
authors.affiliation: Department of Medicine and Center for Alcohol Research, Liver Disease and Nutrition, Salem Medical Center, University of Heidelberg, Heidelberg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Mueller
keywords: alcoholic liver disease; ascites; congestion; intra-abdominal pressure; liver cirrhosis; liver stiffness; noncirrhotic ascites; peritoneal carcinomatosis; transient elastography