title: What is the nature of pancreatic consistency? Assessment of the elastic modulus of the pancreas and comparison with tactile sensation, histology, and occurrence of postoperative pancreatic fistula after pancreaticoduodenectomy.
abstract: BACKGROUND
  Although pancreatic consistency is a factor known to have an impact on the occurrence of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), it usually is assessed subjectively by the surgeon. Measurement of the elastic modulus (EM), a parameter characterizing the elasticity of a material, may be one approach for achieving objective and quantitative assessment of pancreatic consistency. This study was conducted to investigate the utility of determining the EM of the pancreas.
  
  
  METHODS
  Fifty-nine patients who underwent PD and measurement of the EM of the ex vivo pancreas were investigated. Data for EM were compared with the tactile evaluation made by surgeons, histologic findings, and the occurrence of POPF.
  
  
  RESULTS
  The EM of the pancreas was correlated with the tactile evaluation made by the surgeon (soft pancreas, 1.4 ± 2.1 kPa vs hard pancreas, 4.4 ± 5.1 kPa; P < .001). An EM of >3.0 kPa was correlated with histologic findings including increased ratios of azan-Mallory positivity (P = .003) and α-smooth muscle actin positivity (P = .006), a decreased lobular ratio (P = .021), and an increased vessel density (P < .001). Patients with a pancreatic EM of <3.0 kPa had an increased risk of POPF (hazard ratio, 9.333; P = .002).
  
  
  CONCLUSIONS
  Assessment of the EM of the resected pancreas reflects the tactile evaluation made by the surgeon and histological degree of pancreatic fibrosis, and is correlated with the occurrence of POPF after PD.
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Motokazu
authors.initials: M
authors.lastname: Sugimoto
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. Electronic address: shtakaha@east.ncc.go.jp.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kojima
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Gotohda
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kawano
authors.affiliation: Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
authors.affiliation: Department of Hepatobiliary-Pancreatic Surgery, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Konishi
mesh_terms: D055119:Elastic Modulus; D006801:Humans; D010179:Pancreas / Q000033:anatomy & histology* / Q000502:physiology; D010185:Pancreatic Fistula / Q000209:etiology*; D016577:Pancreaticoduodenectomy; D011183:Postoperative Complications / Q000209:etiology*