Portal Venous Flow Rates Research Articles

Viability testing and transplantation of marginal livers (VITTAL) using normothermic machine perfusion: study protocol for an open-label, non-randomised, prospective, single-arm trial

IntroductionThe use of marginal or extended criteria donor livers is increasing. These organs carry a greater risk of initial dysfunction and early failure, as well as inferior long-term outcomes. As...

Effect of Change in Portal Venous Blood Flow Rates on the Performance of a 2.45-GHz Microwave Ablation Device

We have shown that the size and shape of coagulation created by a 2.45-GHz microwave ablation device is not significantly affected by physiological fluctuations in portal venous flow rates.

Computer-Based Liver Volumetry in the Liver Perfusion Simulator

An exact preoperative liver volume calculation is important prior to liver surgery and living-related liver transplantation. However, CT or MRI assessment of preoperative liver volume is associated with an estimation error of 1.2% to 36%, and little data is available on its accuracy on the segmental level. The aim of this study was to validate arterial and portal venous flow rates and gain information on liver volumetry, including liver segments, in the liver perfusion simulator and compare it to in vivo measurements in a porcine model. The arterial and portal venous flow rates and liver volumes of 10 pigs were measured in vivo and compared with the flow rates and volumes ex vivo. CT scans were performed and the volume of the liver and its lobes calculated by water displacement or computer-assistance based on the CT scans. The right lateral lobe was plasticized and reconstructed for the volume calculation. In the liver perfusion simulator, arterial and portal venous flow rates comparable to the in vivo rates were achieved. The liver volume had a mean difference of 10.3% between in vivo and ex vivo measurements. In the liver perfusion simulator, the mean deviation in liver volume between the computer calculation and water displacement was 2.8%. On the segmental level, the Heidelberg algorithm provided an accuracy of 97.7%. The liver perfusion simulator is an excellent device for studies in liver perfusion and volumetry. Furthermore, the simulator is applicable for teaching and performing interventions and surgeries in livers.

The Effect of Hypothermia on Splanchnic Flows and Lung in a Two-Hit Hemorrhagic Shock Model

To evaluate the effect of hypothermia on bacterial translocation, splanchnic vascular flow, lung tissue weight, and levels of malondialdehyde (MDA) and nitric oxide (NO) in a two-hit model of hemorrhagic shock. Thirty rats were randomly allocated into three groups of 10 rats each. In the control group (group C), rats were treated without hemorrhage, and normothermia (37 degrees C) was maintained. In the mild hypothermia group (group MH), rats were subjected to volume-controlled hemorrhage (2 mL/100g) and a rectal temperature of 34 degrees C was maintained. In the normothermic group (group NT), rats were treated as in group MH, except for hypothermia. Seventy-two hours after hemorrhagic shock (first insult), Pseudomonas aeuruginosa was administered intratracheally as a second insult. Finally, mesenteric vascular flow patterns were recorded. Bacterial translocation was studied from tissue samples of spleen, liver, and mesenteric lymph nodes. Blood samples were obtained to evaluate the possible presence of bacteria in the bloodstream. Lung tissue weight ratio, MDA, and NO levels in lung tissue were assessed. Renal, mesenteric, and portal venous flow rates were found to be lower in groups MH and NT in comparison with group C. Blood flow profiles were lower in group NT than in group MH (P<0.05). Bacterial translocation was not observed in group C, and it was detected more often in group NT than in group MH. Lung weight ratio was found to be higher in group NT compared with groups MH and C. Although it did not reach the level of statistical significance, MDA level in the control group was lower than that in the NT group (P=0.085). Hypothermia corrected mesenteric blood flow and decreased the occurrence of bacterial translocation in the two-hit model of hemorrhagic shock and tracheal inoculaton of P. aeruginosa.

Evaluation of portal venous hypertension with cine phase-contrast MR flow measurements: high association of hyperdynamic portal flow with variceal hemorrhage.

Thirty-two patients with portal venous hypertension and endoscopically proved esophageal varices who were being evaluated for possible liver transplantation were studied with cine phase-contrast magnetic resonance (MR) imaging. Flow measurements in the main portal vein were obtained and associated with the presence of variceal hemorrhage within 2 years before the MR examination. Low (hypodynamic) flow was present in 22 patients, while high (hyperdynamic) flow was present in 10 patients. The presence of variceal hemorrhage was significantly associated with a high portal venous flow rate (P = .001), high variceal grade (P = .030), and Child class A or B (P = .003); however, only portal venous flow (P = .006) and variceal grade (P = .044) were found to be associated with variceal hemorrhage in a multiple logistic regression analysis. The portal venous flow rate was significantly higher among patients with Child class A or B disease compared with those with class C disease (median, 24.6 vs 8.0 mL/min.kg; P = .004).