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

BackgroundAlthough 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.MethodsFifty-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.ResultsThe 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).ConclusionAssessment 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.