Allogeneic Venous Grafts of Different Origin Used for Portal Vein Reconstruction After Pancreaticoduodenectomy - Experimental Study.

BACKGROUND: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. MATERIALS AND METHODS: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. RESULTS: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. CONCLUSION: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.

Fluid management guided by a continuous non-invasive arterial pressure device is associated with decreased postoperative morbidity after total knee and hip replacement.

BACKGROUND: The use of goal directed fluid protocols in intermediate risk patients undergoing hip or knee replacement was studied in few trials using invasive monitoring. For this reason we have implemented two different fluid management protocols, both based on a novel totally non-invasive arterial pressure monitoring device and compared them to the standard (no-protocol) treatment applied before the transition in our academic institution. METHODS: Three treatment groups were compared in this prospective study: the observational (CONTROL, N = 40) group before adoption of fluid protocols and two randomized groups after the transition to protocol fluid management with the use of the continuous non-invasive blood pressure monitoring (CNAP®) device. In the PRESSURE group (N = 40) standard variables were used for restrictive fluid therapy. Goal directed fluid therapy using pulse pressure variation was used in the GDFT arm (N = 40). The influence on the rate of postoperative complications, on the hospital length of stay and other parameters was assessed. RESULTS: Both protocols were associated with decreased fluid administration and maintained hemodynamic stability. Reduced rate of postoperative infection and organ complications (22 (55 %) vs. 33 (83 %) patients; p = 0.016; relative risk 0.67 (0.49-0.91)) was observed in the GDFT group compared to CONTROL. Lower number of patients receiving transfusion (4 (10 %) in GDFT vs. 17 (43 %) in CONTROL; p = 0.005) might contribute to this observation. No significant differences were observed in other end-points. CONCLUSION: In our study, the use of the fluid protocol based on pulse pressure variation assessed using continuous non-invasive arterial pressure measurement seems to be associated with a reduction in postoperative complications and transfusion needs as compared to standard no-protocol treatment. TRIAL REGISTRATION: ACTRN12612001014842.

Monoclonal antibody against transforming growth factor Beta 1 does not influence liver regeneration after resection in large animal experiments.

BACKGROUND: Steatohepatitis is a type of histopathological liver injury that can be caused by chemotherapy [chemotherapy-associated steatohepatitis (CASH)] and can progress to liver fibrosis or cirrhosis. CASH impairs liver functions, including liver regeneration. Impaired liver regeneration reduces the number of patients who can undergo liver resection and reduces opportunities for curative therapies. Transforming growth factor-beta (TGFß) is a potent mitotic inhibitor that participates during the last phase of liver regeneration. TGFß has been studied as a potential solution to the development of liver fibrosis or hepatocellular carcinoma. AIM: The first aim of our study was to establish a large animal model of toxic liver injury and test the ability of a monoclonal antibody against TGFß (MAB-TGFß) to increase liver-regeneration capacity. The second aim was to evaluate the degree to which early preoperative administration of MAB-TGFß influenced hepatic parenchyma regeneration following healthy liver resection in a swine experimental model. MATERIALS AND METHODS: Toxic liver injury was induced by alcohol consumption and regular intraperitoneal administration of carbon tetrachloride (CCl4) to piglets for 10 weeks. After 10 weeks, the piglets underwent liver resection of the left lateral and left medial liver lobes. Twenty-four hours after liver resection, MAB-TGFß was administered to the experimental group (10 piglets) and a physiological solution to the control group (10 piglets) through an implemented port-a-cath. In the second part of the study, either MAB-TGFß or a saline solution control were administered at 12 and 4 days prior to resection of the right lobes of healthy liver (six experimental and 10 control group subjects). Observation and follow-up was performed throughout the entire experiment. Ultrasound and biochemical tests (for albumin, cholinesterase, aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase, bilirubin, urea, creatinine and ammonia levels) were performed on postoperative days 1, 3, 7, 10 and 14. A histopathological examination was performed after sacrificing the animals on the 14th postoperative day. RESULTS: No significant differences were observed between groups when using ultrasound volumetry to assess the regenerative volume of the liver in both experiments. The only significant differences found when comparing biochemical parameters between groups were higher serum levels of both creatinine and γ-glutamyl transferase in the experimental group with preoperative administration of MAB-TGFß. There were no differences in the histological analyses of hepatic lobule cross-sectional area nor in the proliferative index between animals receiving MAB-TGFß and those treated with physiological saline solution before resection. Hepatocytic cross-sectional areas were larger in animals treated with physiological solution versus those treated with MAB-TGFß on the operative day; however, these values were comparable between groups by 14 days following resection. CONCLUSION: We established a large animal model of toxic liver injury that is comparable with CASH. The toxic injury that was induced without pause between administrations was probably more extensive than occurs in CASH, and there was no effect of MAB-TGFß administration on liver regeneration. MAB-TGFß administration did not lead to any observable side-effects, indicating that it could be a promising solution for use as an oncologic-targeted treatment.

Respiratory induced dynamic variations of stroke volume and its surrogates as predictors of fluid responsiveness: applicability in the early stages of specific critical states.

Respiratory induced dynamic variations of stroke volume and its surrogates are very sensitive and specific predictors of fluid responsiveness, but their use as targets for volume management can be limited. In a recent study, limiting factors were present in 53 % of surgical patients with inserted arterial line. In the intensive care unit (ICU) population the frequency is presumably higher, but the real prevalence is unknown. Our goal was to study the feasibility of dynamic variations guided initial volume resuscitation in specific critical states. We have performed a 5 year retrospective evaluation of patients admitted with diagnosis sepsis, polytrauma, after high risk surgery or cardiac arrest. Occurrence of major (sedation, mandatory ventilation and tidal volume, open chest and arrhythmias) and minor limiting factors (PEEP level, use of vasopressors and presence of arterial catheter) was screened within the first 24 h after admission. In the study period 1296 patients were hospitalized in our ICU with severe sepsis (n = 242), polytrauma (n = 561), after high risk surgery (n = 351) or cardiac arrest (n = 141). From these patients 549 (42.4 %) fulfilled all major criteria for applicability of dynamic variations. In our evaluation only limited number of patients admitted for polytrauma (51 %), sepsis (37 %), after cardiac arrest (39 %) or surgical procedure (33 %) fulfil all the major criteria for use of dynamic variations at the ICU admission. The prevalence was similar in patients with shock. Occurrence of minor factors can pose further bias in evaluation of these patients. General use of dynamic variations guided protocols for initial resuscitations seems not universally applicable.