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Purpose: We investigated whether detection of ctDNA after resection of colorectal cancer identifies the patients with the highest risk of relapse and, furthermore, whether longitudinal ctDNA analysis allows early detection of relapse and informs about response to intervention. Experimental Design: In this longitudinal cohort study, we used massively parallel sequencing to identify somatic mutations and used these as ctDNA markers to detect minimal residual disease and to monitor changes in tumor burden during a 3-year follow-up period. Results: A total of 45 patients and 371 plasma samples were included. Longitudinal samples from 27 patients revealed ctDNA postoperatively in all relapsing patients (n = 14), but not in any of the nonrelapsing patients. ctDNA detected relapse with an average lead time of 9.4 months compared with CT imaging. Of 21 patients treated for localized disease, six had ctDNA detected within 3 months after surgery. All six later relapsed compared with four of the remaining patients [HR, 37.7; 95% confidence interval (CI), 4.2–335.5; P < 0.001]. The ability of a 3-month ctDNA analysis to predict relapse was confirmed in 23 liver metastasis patients (HR 4.9; 95% CI, 1.5–15.7; P = 0.007). Changes in ctDNA levels induced by relapse intervention (n = 19) showed good agreement with changes in tumor volume (κ = 0.41; Spearman ρ = 0.4). Conclusions: Postoperative ctDNA detection provides evidence of residual disease and identifies patients at very high risk of relapse. Longitudinal surveillance enables early detection of relapse and informs about response to intervention. These observations have implications for the postoperative management of colorectal cancer patients. Clin Cancer Res; 23(18); 5437–45. ©2017 AACR. more...

Background One of the main concerns using low-dose (LD) CT for evaluation of patients with suspected intestinal obstruction or pneumoperitoneum is the potential need to make an additional standard-dose (SD) CT scan (retake) due to insufficient diagnostic accuracy of the LD CT. Purpose To determine the frequency of retakes and evaluate the diagnostic accuracy of LD CT for the assessment of intestinal obstruction and pneumoperitoneum. Material and Methods This retrospective study registered all LD CT scans over a one-year period at Aarhus University Hospital, Denmark in patients with suspected intestinal obstruction or perforation, comprising a total of 643 LD CT scans. A retake was defined as a SD CT scan of the abdomen and pelvis performed with or without intravenous contrast within 72 h after the initial LD CT due to either continued suspicion of intestinal obstruction or perforation or due to unclarified secondary findings. The sensitivity and specificity of LD CT for diagnosing intestinal obstruction and pneumoperitoneum compared to the discharge diagnoses of the scanned patients were determined. Results The frequency of retakes was 3%. The overall LD CT sensitivity and specificity for assessment of patients with suspected intestinal obstruction and pneumoperitoneum was 83% and 99%, respectively, but higher in certain subgroups. Conclusions LD CT led to few retakes and had a high diagnostic accuracy for diagnosing intestinal obstruction and pneumoperitoneum. Thus, LD CT can be recommended as the examination of choice in patients with suspected intestinal obstruction or perforation in order to reduce radiation dose. more...

Aim The Pringle maneuver is a way to reduce blood loss during liver surgery. However, this may result in ischemia/reperfusion injury in the development of which Kupffer cells play a central role. Corticosteroids are known to have anti-inflammatory effects. Our aim was to investigate whether a conjugate of dexamethasone and antibody against the CD163 macrophage cell surface receptor could reduce ischemia/reperfusion injury in the rat liver. Methods Thirty-six male Wistar rats were used for the experiments. Animals were randomly divided into four groups of eight receiving anti-CD163-dexamethasone, high dose dexamethasone, low dose dexamethasone or placebo intravenously 18 h before laparotomy with subsequent 60 min of liver ischemia. After reperfusion for 24 h the animals had their liver removed. Bloods were drawn 30 min and 24 h post ischemia induction. Liver cell apoptosis and necrosis were analyzed by stereological quantification. Results After 24 h' reperfusion, the fraction of cell in non-necrotic tissues exhibiting apoptotic profiles was significantly lower in the high dose dexamethasone (p = 0.03) and anti-CD163-dex (p = 0.03) groups compared with the low dose dexamethasone and placebo groups. There was no difference in necrotic cell volume between groups. After 30 min of reperfusion, levels of haptoglobin were significantly higher in the anti-CD163-dex and high dose dexamethasone groups. Alanine aminotransferase and alkaline phosphatase were significantly higher in the high dose dexamethasone group compared to controls after 24 h' reperfusion. Conclusions We show that pharmacological preconditioning with anti-CD163-dex and high dose dexamethasone reduces the number of apoptotic cells following ischemia/reperfusion injury., Highlights • We investigated the effect of pharmacologic preconditioning with HDD, LDD and anti-CD163-dex on ischemia/reperfusion injury. • Liver cell apoptosis and necrosis were analyzed by stereological quantification. • Anti-CD163-dex and high dose dexamethasone reduces the number of apoptotic cells following ischemia/reperfusion injury. more...

Extended hepatectomies may result in posthepatectomy liver failure, a condition with a high mortality. The main purpose of the present study was to investigate and compare the gene expression profiles in rats subjected to increasing size of partial hepatectomy (PH). Thirty Wistar rats were subjected to 30%, 70%, or 90% PH, sham operation, or no operation. Twenty-four hours following resection, liver tissue was harvested and genome-wide expression analysis was performed. Cluster analysis revealed two main groupings, one containing the PH(90%) and one containing the remaining groups [baseline, sham, PH(30%), and PH(70%)]. Categorization of specific affected molecular pathways in the PH(90%) group revealed a downregulation of cellular homeostatic function degradation and biosynthesis, whereas proliferation, cell growth, and cellular stress and injury were upregulated in the PH(90%) group. After PH(90%), the main upregulated pathways were mTOR and ILK. The main activated upstream regulators were hepatocyte growth factor and transforming growth factor. With decreasing size of the future liver remnant, the liver tended to prioritize expression of genes involved in cell proliferation and differentiation at the expense of genes involved in metabolism and body homeostasis. This prioritizing may be an essential molecular explanation for posthepatectomy liver failure. more...

Background Ischemic preconditioning (IPC) has been shown to protect the liver against ischemia-reperfusion (I/R) injuries. However, ischemic post-conditioning has received little attention. The aim of the present study was to quantify and compare the hepato-protective properties of IPC and IPO, for the first time, using unbiased design-based stereological methods. Methods We divided 67 rats into four groups: sham, liver ischemia (LI), IPC, and IPO. Rats were subjected to 60 min LI, followed by 4- or 24-h reperfusion. We performed quantification of (NVR) and apoptotic cell profile number. Results We observed no significant differences in NVR between ischemic groups after 4 h. After 24-h reperfusion, NVR had increased to 70% in the LI group, compared with 51% ( P = 0.02) and 49% ( P = 0.01) in the IPC and IPO groups, respectively. After 4-h reperfusion, the apoptotic cell number was significantly higher in all ischemic groups than in the sham group; we detected no difference between ischemic groups. After 24-h reperfusion, we detected a significantly lower number of apoptotic cell profiles in the IPC group than in the LI group ( P = 0.02). The mean number of apoptotic cell profiles decreased insignificantly in the IPO group ( P = 0.06). Liver parameters were at all time comparable between groups. Conclusions After I/R, IPC and IPO reduce the degree of hepatocellular injury. Both methods are equally efficient at preventing hepatocellular necrosis. Furthermore, apoptosis is significantly lower after IPC. more...

Circulating liver enzymes such as alanine transaminase are often used as markers of hepatocellular damage. Ischaemia/reperfusion (I/R) injury is an inevitable consequence of prolonged liver ischaemia. The aim of this study was to examine the correlation between liver enzymes and volume of liver cell necrosis after ischaemia/reperfusion injuries, using design-unbiased stereological methods. Forty-seven male Wistar rats were subjected to 1 h of partial liver ischaemia, followed by either 4 or 24 h of reperfusion. Within each group, one-third of animals were subjected to ischaemic preconditioning and one-third to ischaemic postconditioning. At the end of reperfusion, blood and liver samples were collected for analysis. The volume of necrotic liver tissue was subsequently correlated to circulating markers of I/R injury. Correlation between histological findings and circulating markers was performed using Pearson's correlation coefficient. Alanine transferase peaked after 4 h of reperfusion; however, at this time-point, only mild necrosis was observed, with a Pearson's correlation coefficient of 0.663 (P = 0.001). After 24 h of reperfusion, alanine aminotransferase was found to be highly correlated to the degree of hepatocellular necrosis R = 0.836 (P = 0.000). Furthermore, alkaline phosphatase (R = 0.806) and α-2-macroglobulin (R = 0.655) levels were also correlated with the degree of necrosis. We show for the first time that there is a close correlation between the volume of hepatocellular necrosis and alanine aminotransferase levels in a model of I/R injury. This is especially apparent after 24 h of reperfusion. Similarly, increased levels of alkaline phosphatase and α-2-macroglobulin are correlated to the volume of liver necrosis. more...

Ischemic pre (IPC)- and postconditioning (IPO) protect the liver against ischemia/reperfusion injuries (IRI). Conditioning involves several different trigger factors, mediators, and effectors, many of which are affected during the early phase of reperfusion, ultimately resulting in decreased liver injuries. The aim of the present study was to investigate the genomic response induced by IPC and IPO in ischemia/reperfusion-damaged rat liver biopsies. Forty-eight male Wistar rats were divided into five groups: sham ( n = 8), IRI ( n = 10), IPC ( n = 10), IPO ( n = 10), and IPC + IPO ( n = 10). The rat livers were subjected to 30 min of ischemia. Liver biopsies and blood samples were taken after 30 min of reperfusion. The biopsies were analyzed using cDNA microarrays with validation by quantitative RT-PCR. The significance analysis of microarray was used to identify genes with changed expression levels. A comparison analysis of the intervention groups showed a highly increased number of genes, with significantly different expression in the conditioned groups compared with the IRI group. A total of 172 genes were identified as the most highly affected, and these genes showed similar patterns with regard to the up- and downregulated expression levels within the conditioned groups. Pathway analysis of the 172 genes identified four networks that were involved in increased gene expression, cellular growth, and proliferation. In conclusion, the present study demonstrated that IPC, IPO, and IPC + IPO had pronounced effects on the expression levels of a large number of genes during early reperfusion. IPC, IPO, and IPC + IPO seem to mediate their protective effects by regulating the same genes and genetic networks. These identified networks are known to be involved in maintaining cellular homeostasis. more...

Udgivelsesdato: 2010-Oct Background: During surgery, ischaemic pre- (IPC) and post-conditioning (IPO) protects the liver against ischaemia/reperfusion injuries (I/R-injuries). The impact of ischaemic conditioning on liver regeneration has been less well studied. Angiogenesis is an important part of liver regeneration after hepatectomy. The aim of the present study was to investigate the effect of ischaemia/reperfusion and ischaemic conditioning on the expression of genes with angiogenic potential in a model of rat liver ischaemia. Methods: A model of total liver ischaemia (30 min) and reperfusion (30 min) was employed using Wistar rats. Rats were randomized into five groups: (C) control (IRI) ischaemic, IPC, IPO and IPC + IPO. Liver enzymes were sampled at the end of reperfusion. Liver biopsies were analysed using cDNA microarrays. Results: Alanine aminotransferase (ALT) increased significantly in all the ischaemic groups compared with controls (P= 0.000). Searching databases 99 genes involved in rat liver angiogenesis were identified. Compared with group (C) the number of genes significantly up-regulated was as follows: IRI (n= 5), IPC (n= 24), IPO (n= 33) and IPC + IPO (n= 18). No genes were down-regulated in the four groups compared with controls. Conclusion: Ischaemic conditioning, as demonstrated in the present study, seems to be potent activators of angiogenic genes. This might be favourable to the regenerating liver. more...

Introduction Surgical resection is the gold standard in treatment of hepatic malignancies, giving the patient the best chance to be cured. The liver has a unique capacity to regenerate. However, an inflammatory response occurs during resection, in part mediated by Kupffer cells, that influences the speed of regeneration. The aim of this study was to investigate the effect of a Kupffer cell targeted anti-inflammatory treatment on liver regeneration in rats. Methods Two sets of animals, each including four groups of eight rats, were included. Paired groups from each set received treatment with placebo, low dose dexamethasone, high dose dexamethasone or low dose anti-CD163 dexamethasone. Subsequently, the rats underwent 70% partial hepatectomy. The two sets were evaluated on postoperative day 2 or 5, respectively. Blood was drawn for circulating markers of inflammation and liver cell damage; liver tissue was sampled for analysis of regeneration rate and proliferation index. Results The high dose dexamethasone group had significantly lower body and liver weight than the placebo and anti-CD163-dex groups. There were no differences in liver regeneration rates between groups. Hepatocyte proliferation was completed faster in the placebo group, although this was not significant. The anti-CD163-dex group showed increased blood levels of albumin and alanine aminotransferase and a diminished inflammatory response in terms of significantly reduced haptoglobin, α2-macroglobulin and Interleukine-6. Conclusion Low dose dexamethasone targeted to Kupffer cells does not affect histological liver cell regeneration after 70% hepatectomy in rats, but reduces the inflammatory response judged by circulating markers of inflammation., Highlights • Use of anti-CD163-dexamethasone is an attractive strategy for anti-inflammatory treatment. • In the present study the impact of anti-CD163 dexamethasone on liver regeneration in rats was studied. • We show that low dose anti-CD163 dexamethasone has no negative effect on liver regeneration after 70% hepatectomy in rats. Characters should then be down to 122. more...

Aims: Acute acalculous cholecystitis can be treated with percutaneous cholecystostomy in critically ill patients unfit for surgery. However, the evidence on the outcome is sparse. We conducted a retrospective analysis of acute acalculous cholecystitis patients treated with percutaneous cholecystostomy during a 10-year study period. Methods: An observational study of 56 consecutive patients treated with percutaneous cholecystostomy for acute acalculous cholecystitis was conducted in the period from 1 June 2002 to 31 May 2012. All data were obtained by review of medical records. Results: A total of 56 consecutive patients were treated with percutaneous cholecystostomy for acute acalculous cholecystitis. Six patients (10.7%) died within 30 days after the procedure. Percutaneous cholecystostomy could serve as a definitive treatment option in 45 patients (80.4%), whereas 1 patient (1.8%) required cholecystectomy due to recurrence of cholecystitis. Four patients (7.1%) were treated with percutaneous cholecystostomy as a bridging procedure to subsequent elective laparoscopic cholecystectomy within a median of 8.8 months (range: 7.7–33.4 months). There was no significant difference in the risk of cholecystitis recurrence between patients with (6/37) and without (2/3) contrast passage to the duodenum on cholangiography ( p = 0.096). Conclusion: Percutaneous cholecystostomy is successful as a definitive treatment option in the majority of patients with acute acalculous cholecystitis. It is associated with a low rate of mortality and subsequent cholecystectomy. more...

BACKGROUND: Sorafenib, a multikinase inhibitor, has been shown to halt the growth of hepatocellular carcinoma. The aim of the present study was to investigate the effect of Sorafenib on liver regeneration in healthy rats.METHODS: In two substudies we examined the effect of pre- or post-operative treatment with Sorafenib (15 mg/kg/d). Wistar rats (n = 120) received either Sorafenib (S) or placebo (P). After 70% partial hepatectomy, the rats were euthanized on postoperative days 2, 4, or 8. Body weight and liver weight were recorded and regeneration rate (RR) calculated. Hepatocyte proliferation was estimated by immunohistochemistry for Ki-67 antigen using unbiased stereological methods.RESULTS: Eleven animals (9%) died after surgery. In the preoperative substudy, lower body weight gains during the gavage period in the S group were found. No difference between groups S and P regarding liver weight gain, liver RRs, and hepatocyte proliferation on postoperative days 2 and 4 were found. In the postoperative substudy, significantly lower values of liver weight gain, liver RRs, and hepatocyte proliferation were found in the S group.CONCLUSIONS: In our rat model, Sorafenib did not increase posthepatectomy mortality. Postoperative treatment significantly impaired liver regeneration. Preoperative treatment impaired body weight during the gavage period, but was without effect on liver regeneration. more...

Transarterial chemoembolization (TACE) is used as palliative treatment of hepatocellular carcinoma (HCC). Most publications are from HCC patient populations where viral hepatitis is the primary cause of liver disease. In the Nordic countries, most patients have either alcohol-induced cirrhosis or are noncirrhotic. The aim of this single-center study was to evaluate patient characteristics, survival, and side effects of TACE in a Danish referral center for HCC treatment.Fifty-nine consecutive patients with HCC, treated with TACE, either chemoembolization with drug-eluting beads or conventional-TACE with Lipiodol, were included in the study. Their medical records were retrospectively reviewed, computed tomography images analyzed, and biochemical markers recorded. The primary endpoint was overall survival. Analyses were by intention to treat.Thirty-five patients (59 %) had HCC on a background of liver cirrhosis most often caused by alcohol (60 % of cirrhotics or 35 % overall). Before the first chemoembolization, the patients had a median Child-Pugh score of 6 (5-7) and a median MELD score of 10 (6-21). Median survival after chemoembolization was 18.9 months (13.1-24.7). TACE patients were hospitalized for an average of 3 days (2-30). Prolonged stay was most often due to side effects-eg. pain (31 %), fever (14 %), nausea (10 %), and infection (10 %). Thirty-three patients (56 %) did not have any side effects.In this cohort, we observed an acceptable survival following TACE without significant side effects. more...

Background Rodent models have been used to evaluate aspects of liver regeneration. The aim of the present study was to investigate the natural history of liver regeneration in healthy rats. Methods A 70% partial hepatectomy was performed in 64 rats. The animals were randomised into 8 groups and evaluated on postoperative days one to eight. Hepatocyte proliferation was evaluated by immunohistochemistry using unbiased stereological principles. Results The mean rat body weight was 238 g (211–287). The mean weight of the resected liver was 6.3 g (5.2–7.3) and the estimated mean total liver weight was 8.9 g (7.4–10.4). Both liver weight analysis and regeneration rate showed an ascending curve, with a maximum slope on postoperative days 1–4, reaching a steady state on days 5–8. Hepatocyte proliferation (positive Ki-67 cell profiles pr. mm 2 ) was high (250 cell profiles/mm 2 ) on postoperative days 1–3 and tapered off on day 5. Conclusion Seventy percent partial hepatectomy in healthy rats induces a rapid regenerative response and PODs 2, 4 and 8 seems optimal for assessing hepatic growth in future studies. more...

Background Sorafenib is a multikinase inhibitor with antiangiogenic and antiproliferative properties, approved for the treatment of hepatocellular carcinoma. The effect of Sorafenib on liver regeneration in healthy rats was investigated. Methods Sixty Wistar rats received either Sorafenib (group S; 15 mg/kg) or placebo for 14 days prior to resection and until sacrifice. After a 70% partial hepatectomy, the rats were euthanized on post-operative days (POD) 2, 4 or 8. Hepatocyte proliferation was estimated by immunohistochemistry for Ki-67 antigen using stereological methods on sections prepared by systematic uniform random sampling. Results Seven animals (12%) died after surgery. Death rates were similar in treated rats and controls. At hepatectomy, the body weight was significantly lower in group S rats. The liver weight and regeneration rates were lower in group S rats on PODs 2, 4 and 8. Hepatocyte proliferation was significantly lower in group S animals on PODs 2 and 4. Alanine aminotransferase ALAT was significantly higher in the Sorafenib-treated group on PODs 2, 4 and 8. Alkaline phosphatase ALP and bilirubin levels were similar in the two groups, although bilirubin was elevated in group S rats on POD 8. Conclusion In this rat model, Sorafenib did not increase post-hepatectomy mortality, but was associated with a significant impaired liver weight gain, regeneration rates and hepatocyte proliferation. more...

Background The surgical strategy for the treatment of colorectal cancer and synchronous liver metastases remains controversial. The aim of the present study was to investigate the effects of colonic resection on liver function and regeneration in a rat model. Methods Ninety-six Sprague-Dawley rats were block-randomized into six groups: Group I had a laparotomy performed. Group II had 1 cm colon resected and anastomosed. Group III and V had 40% or 70% of the liver resected, respectively. Additionally Group IV and VI had 1 cm colon resected and anastomosed, respectively. Body weight was recorded on postoperative day 0, 3, 5 and 7. Rats were sacrificed on postoperative day 7 by rapid collection of blood from the inferior vena cava, and endotoxin levels were measured. Remnant liver function was evaluated by means of branched amino acids to tyrosine ratio. Liver regeneration was calculated by (liver weight per 100 g of the body weight at sacrifice/preoperative projected liver weight per 100 g of the body weight) × 100. Results The total number of complications was significantly higher in Group VI than Group I, III, IV, and V. Body weight and branched amino acids to tyrosine ratio were both significantly lower in rats that had simultaneous colonic and liver resection performed. Hepatic regeneration rate was significantly higher in the simultaneous colectomy group. Systemic endotoxin levels were unaffected by simultaneous colectomy on postoperative day 7. Conclusions In our model morbidity seems to be related to the extent of hepatic resection. In rats undergoing liver resection, simultaneous colectomy induced a higher degree of hepatic regeneration rate. Body weight changes and branched amino acids to tyrosine ratio were negatively affected by simultaneous colectomy. more...

BackgroundPercutaneous cholecystostomy (PC) can be used to treat patients with acute calculous cholecystitis (ACC) who are considered to be unfit for surgery. However, this procedure has been insufficiently investigated. This paper presents the results of a 10-year experience with this treatment modality.MethodsA retrospective observational study of all consecutive patients treated with PC for ACC in the period from 1 May 2002 to 30 April 2012 was conducted. All data were collected from patients' medical records.ResultsA total of 278 patients were treated with PC for ACC. Of these, 13 (4.7%) died within 30 days, 28 (10.1%) underwent early laparoscopic cholecystectomy and three (1.1%) patients were lost from follow-up. Of the remaining 234 patients, 55 (23.5%) were readmitted for the recurrence of cholecystitis. In 128 (54.7%) patients, PC was the definitive treatment (median follow-up time: 5 years), whereas 51 (21.8%) patients were treated with elective laparoscopic cholecystectomy. The frequency of recurrence of cholecystitis in patients with contrast passage to the duodenum on cholangiography was lower than that in patients without contrast passage (21.1% versus 36.7%; P = 0.037).ConclusionsThe present study, which is the largest ever conducted in this treatment area, supports the hypothesis that PC is an effective treatment modality for critically ill patients with ACC unfit for surgery and results in a low rate of 30-day mortality. more...

BACKGROUND: Although wound healing is a simple regenerative process that is critical after surgery, it has been shown to be impaired under psychological stress. The liver has a unique capacity to regenerate through highly complex mechanisms. The aim of this study was to investigate the effects of chronic stress, which may induce a depression-like state, on the complex process of liver regeneration in rats.METHODS: Twenty rats were included in this study. The animals received either a standard housing protocol or were subjected to a Chronic Mild Stress (CMS) stress paradigm. All rats underwent a 70 % partial hepatectomy (PHx). The animals were evaluated on postoperative day 2 or 4. Blood samples were collected to examine circulating markers of inflammation and liver cell damage. Additionally, liver tissues were sampled to evaluate liver weight and regeneration rate.RESULTS: None of the animals died during the study. There were no differences between in body weight, liver weight, liver regeneration rate or biochemical markers at any time during the study.CONCLUSION: The results of this study indicate that stress and the induction of depression-like state do not affect the process of liver regeneration after 70 % hepatectomy in rats. more...

Background: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is used to accelerate growth of the future liver remnant. We investigated alternative methods for increasing the future liver remnant. Methods: A total of 152 rats were randomized as follows: (1) sham; (2) portal vein ligation; (3) portal vein ligation/surgical split (ALPPS); (4) portal vein ligation/split of the liver with a radiofrequency ablation needle; (5) portal vein ligation/radiofrequency ablation of the deportalized liver (portal vein ligation/radiofrequency ablation necrosis in the deportalized liver); (6) portal vein ligation/radiofrequency ablation of the future liver remnant (portal vein ligation/radiofrequency ablation-future liver remnant); and (7) controls. Animals were evaluated on postoperative days 2 and 4. Bodyweight, liver parameters, hepatic regeneration rate, proinflammatory cytokines, hepatocyte proliferation, and gene expression were measured. Results: Hepatic regeneration rate indicated a steady increase in all intervention groups compared with sham rats (P < .001). At postoperative day 2, the hepatic regeneration rate was significantly higher in the portal vein ligation/radiofrequency ablation necrosis in the deportalized liver group than in the portal vein ligation group (P = .039). On postoperative day 4, we found significant differences between the portal vein ligation group and the ALPPS (P = .015), portal vein ligation/split of the liver with a radiofrequency ablation needle (P = .010), and portal vein ligation/radiofrequency ablation necrosis in the deportalized liver (P = .046) groups. Hepatocyte proliferation was significantly higher at all times compared with sham rats. On postoperative day 4, we found a significantly higher proliferation in groups 3, 4, 5, and 6 compared to portal vein ligation. Gene analysis revealed upregulation of genes involved in cellular proliferation and downregulation of genes involved in cellular homeostasis in all intervention groups. Between the intervention groups, gene expression was nearly identical. Biochemical markers and proinflammatory cytokines were comparable between groups. Conclusion: The surplus liver regeneration after ALPPS is probably mediated through parenchymal damage and subsequent release of growth stimulators, which again upregulates genes involved in cellular regeneration and downregulates genes involved in cellular homeostasis. We also demonstrate that growth of the future liver remnant, comparable to that seen after ALPPS, could be achieved by radiofrequency ablation treatment of the deportalized liver, that is, a procedure in which the initial step in humans can be performed percutaneously. more...

Background: Ischemic pre- and postconditioning protects the liver against ischemia/reperfusion injuries. The aim of the present study was to examine how ischemic pre- and postconditioning affects gene expression of hypoxia inducible factor 1a (HIF-1a), vascular endothelial growth factor A (VEGF-A) and transforming growth factor b (TGFb) in liver tissue. Methods: 28 rats were randomized into five groups: control; ischemia/reperfusion; ischemic preconditioning (IPC); ischemic postconditioning (IPO); combined IPC and IPO. IPC consisted of 10 min of ischemia and 10 min of reperfusion. IPO consisted of three cycles of 30 sec. reperfusion and 30 sec. of ischemia. Results: HIF-1a mRNA expression was significantly increased after liver ischemia compared to controls (p = 0.010). HIF-1a mRNA expression was significantly lower in groups subjected to IPC or combined IPC and IPO when compared to the ischemia/reperfusion group (p = 0.002). VEGF-A mRNA expression increased in the ischemia/ reperfusion or combined IPC and IPO groups when compared to the control group (p < 0.05). Conclusion: Ischemic conditioning seems to prevent HIF-1a mRNA induction in the rat liver after ischemia and reperfusion. This suggests that the protective effects of ischemic conditioning do not involve the HIF-1 system. On the other hand, the magnitude of the HIF-1a response might be a marker for the degree of I/R injuries after liver ischemia. Further studies are needed to clarify this issue. Background more...