Impact of reconstructed portal vein morphology on postoperative nutritional status in pancreatoduodenectomy: a computational fluid dynamics study.

This study evaluated the impact of reconstructed portal vein/superior mesenteric vein (PV/SMV) morphology on the long-term nutritional status following pancreatoduodenectomy (PD) using computational fluid dynamics (CFD). Twenty-four patients who underwent PD with PV/SMV resection and reconstruction without tumor recurrence for over 9 months after the operation were enrolled in the study. Three-dimensional models were constructed from computed tomography images obtained 3-6 months postoperatively. The pressure (p) at the inlet and turbulence dissipation rate (ε) at the outlet were investigated in the models. Patients with values of either p or ε above the upper interquartile range were classified as the poor flow group. The prognostic nutritional index improvement rate was significantly lower at 9 postoperative months in the poor flow group than in the good flow group (P = 0.016). This finding indicates the utility of a CFD analysis for evaluating the reconstructed PV/SMV morphology.

Impact of the inferior vena cava morphology on fluid dynamics of the hepatic veins.

We reported previously that a large vertical interval between the hepatic segment of the inferior vena cava (IVC) and right atrium (RA), referred to as the IVC-RA gap, was associated with more intraoperative bleeding during hemi-hepatectomy. We conducted a computational fluid dynamics (CFD) study to clarify the impact of fluid dynamics resulting from morphologic variations around the liver. The subjects were 10 patients/donors with a large IVC-RA gap and 10 patients/donors with a small IVC-RA gap. Three-dimensional reconstructions of the IVC and hepatic vessels were created from CT images for the CFD study. Median pressure in the middle hepatic vein was significantly higher in the large-gap group than in the small-gap group (P = 0.008). Differences in hepatic vein pressure caused by morphologic variation in the IVC might be one of the mechanisms of intraoperative bleeding from the hepatic veins.

Unification venoplasty during two versus one venous reconstruction: Computational fluid dynamics study.

Two versus 1 venous reconstruction is sometimes required for Hepato-Biliary-Pancreatic and Transplantation surgery. V-shape venoplasty is considered to be useful knack of unification method during 2 versus 1 venous reconstruction in clinical practice. The usefulness of V-shape unification venoplasty was proven by the present computational fluid dynamics study.