Preoperative predictors for non-resectability in perihilar cholangiocarcinoma.

INTRODUCTION: Explorative laparotomy without subsequent curative-intent liver resection remains a major clinical problem in the treatment of perihilar cholangiocarcinoma (pCCA). Thus, we aimed to identify preoperative risk factors for non-resectability of pCCA patients. MATERIAL AND METHODS: Patients undergoing surgical exploration between 2010 and 2022 were eligible for the analysis. Separate binary logistic regressions analyses were used to determine risk factors for non-resectability after explorative laparotomy due to technical (tumor extent, vessel infiltration) and oncological (peritoneal carcinomatosis, distant nodal or liver metastases)/liver function reasons. RESULTS: This monocentric cohort comprised 318 patients with 209 (65.7%) being surgically resected and 109 (34.3%) being surgically explored [explorative laparotomy: 87 (27.4%), laparoscopic exploration: 22 (6.9%)]. The median age in the cohort was 69 years (range 60-75) and a majority had significant comorbidities with ASA-Score ≥ 3 (202/318, 63.5%). Statistically significant (p < 0.05) risk factors for non-resectability were age above 70 years (HR = 3.76, p = 0.003), portal vein embolization (PVE, HR = 5.73, p = 0.007), and arterial infiltration > 180° (HR = 8.05 p < 0.001) for technical non-resectability and PVE (HR = 4.67, p = 0.018), arterial infiltration > 180° (HR = 3.24, p = 0.015), and elevated CA 19-9 (HR = 3.2, p = 0.009) for oncological/liver-functional non-resectability. CONCLUSION: Advanced age, PVE, arterial infiltration, and elevated CA19-9 are major risk factors for non-resectability in pCCA. Preoperative assessment of those factors is crucial for better therapeutical pathways. Diagnostic laparoscopy, especially in high-risk situations, should be used to reduce the amount of explorative laparotomies without subsequent liver resection.

Living-Donor Liver Transplantation for a Large Hepatocellular Carcinoma in a Genetically Identical Twin Sister.

Hepatocellular carcinoma (HCC) is, to date, the most common malignant tumor of the liver and is commonly staged with the Milan criteria. While deceased-donor liver transplantations (DDLT) are reserved for patients within the Milan criteria, living-donor liver transplantation (LDLT) might be a curative option for patients outside the Milan criteria. We here report a case of a 32-year-old woman who developed a giant, unresectable HCC out of a hepatocellular adenoma (HCA) after a pregnancy. The genetically identical twin sister donated her left hemi-liver after ethical approval and preoperative screening. No long-term immunosuppressive therapy was necessary, and after more than eight years, both are in perfect health and the recipient gave birth to a second child. This case shows that in certain situations large HCCs outside the standard criteria can be cured by LT. Careful evaluation of both donor and recipient should be performed for indications like this to assure optimal clinical outcome.

Survival after combined resection and ablation is not inferior to that after resection alone, in patients with four or more colorectal liver metastases.

PURPOSE: Colorectal liver metastases (CRLM) are the predominant factor limiting survival in patients with colorectal cancer. Multimodal treatment strategies are frequently necessary to achieve total tumor elimination. This study examines the efficacy of liver resection combined with local ablative therapy in comparison to liver resection only, in the treatment of patients with ≥ 4 CRLM. METHODS: This retrospective cohort study was conducted at the University Hospital RWTH Aachen, Germany. Patients with ≥ 4 CRLM in preoperative imaging, who underwent curative resection between 2010-2021, were included. Recurrent resections and deaths in the early postoperative phase were excluded. Ablation modalities included radiofrequency or microwave ablation, and irreversible electroporation. Differences in overall- (OS) and recurrence-free-survival (RFS) between patients undergoing combined resection-ablation vs. resection only, were examined. RESULTS: Of 178 included patients, 46 (27%) underwent combined resection-ablation and 132 (73%) resection only. Apart from increased rates of adjuvant chemotherapy in the first group (44% vs. 25%, p = 0.014), there were no differences in perioperative systemic therapy. Kaplan-Meier and log-rank test analyses showed no statistically significant differences in median OS (36 months for both, p = 0.638) or RFS (9 months for combined resection-ablation vs. 8 months, p = 0.921). Cox regression analysis showed a hazard ratio of 0.891 (p = 0.642) for OS and 0.981 (p = 0.924) for RFS, for patients undergoing resection only. CONCLUSION: For patients with ≥ 4 CRLM, combined resection-ablation is a viable option in terms of OS and RFS. Therefore, combined resection-ablation should be considered for complete tumor clearance, in patients with multifocal disease.

Health-related quality of life outcomes following Roux-en-Y gastric bypass versus one anastomosis gastric bypass.

PURPOSE: Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) are effective standard bariatric surgeries with comparable weight loss and remission of obesity-related comorbidities. As procedure-specific health-related quality of life (HrQoL) outcomes have not been directly compared thus far, we conducted this questionnaire-based study. METHODS: Two hundred forty patients after undergoing either RYGB or OAGB between 2011 and 2016 were contacted and asked to fill out SF36 and BAROS questionnaires. All statistical analysis was performed with Microsoft Excel and GraphPad Prism. Primary objectives were procedure-dependent differences in HrQoL. Secondary objectives were weight loss and remission of comorbidities. RESULTS: One hundred nineteen of 240 contacted patients (49.6%) replied, 58 after RYGB (48.7%) and 61 after OAGB (51.3%). Follow-up period was < 24 months in 52 and > 24 months in 64 evaluable patients. The mean age was 46 years (range 23 to 71). Regarding the < 24 months groups, both physical and psychological SF36 sum scales were comparably high. Only the subcategory "general health perception" was significantly better after RYGB. Significantly higher excess weight loss (EWL) after RYGB (88.81%) compared to OAGB (66.25%) caused significantly better global < 24 months BAROS outcomes, whereas remission of comorbidities and HrQoL was similar. Both > 24 months groups showed high SF36-HrQoL sum scales. Global mean BAROS results after > 24 months were "very good" in both procedures. EWL in RYGB (80.81%) and in OAGB (81.36%) were comparably excellent. CONCLUSION: Concerning SF36 and BAROS evaluated HrQoL in early and late postoperative phases, both procedures demonstrated comparable and relevant improvements. Further (preferably randomized) studies should include evaluation of preoperative HrQoL.

Time to surgery is not an oncological risk factor in HCC patients undergoing liver resection.

PURPOSE: Given limitations of the health care systems in case of unforeseeable events, e.g., the COVID pandemic as well as trends in prehabilitation, time from diagnosis to surgery (time to surgery, (TTS)) has become a research issue in malignancies. Thus, we investigated whether TTS is associated with oncological outcome in HCC patients undergoing surgery. METHODS: A monocentric cohort of 217 patients undergoing liver resection for HCC between 2009 and 2021 was analyzed. Individuals were grouped according to TTS and compared regarding clinical characteristics. Overall survival (OS) and recurrence-free survival (RFS) was compared using Kaplan-Meier analysis and investigated by univariate and multivariable Cox regressions. RESULTS: TTS was not associated with OS (p=0.126) or RFS (p=0.761) of the study cohort in univariate analysis. In multivariable analysis age (p=0.028), ASA (p=0.027), INR (0.016), number of HCC nodules (p=0.026), microvascular invasion (MVI; p<0.001), and postoperative complications (p<0.001) were associated with OS and INR (p=0.005), and number of HCC nodules (p<0.001) and MVI (p<0.001) were associated with RFS. A comparative analysis of TTS subgroups was conducted (group 1, ≤30 days, n=55; group 2, 31-60 days, n=79; group 3, 61-90 days, n=45; group 4, >90 days, n=38). Here, the median OS were 62, 41, 38, and 40 months (p=0.602 log rank) and median RFS were 21, 26, 26, and 25 months (p=0.994 log rank). No statistical difference regarding oncological risk factors were observed between these groups. CONCLUSION: TTS is not associated with earlier tumor recurrence or reduced overall survival in surgically treated HCC patients.

Roux-en-Y Versus One Anastomosis Gastric Bypass as Redo-Operations Following Sleeve Gastrectomy: A Retrospective Study.

BACKGROUND: Aim of this study was to improve knowledge about the best conversional bariatric procedure following sleeve gastrectomy (SG). METHODS: Data of conversional Roux-en-Y gastric bypass (RYGB) and of one anastomosis gastric bypass (OAGB) after SG were collected prospectively and analyzed retrospectively. Weight loss parameters, gastroesophageal reflux disease (GERD) and comorbidities outcomes were recorded. RESULTS: Total of 123 patients (90 female, mean age 44 ± 0.9 years, mean body mass index (BMI) 42 ± 0.8 kg/m2) had either RYGB (n = 68) or OAGB (n = 55). Perioperative mortality was zero. Mean surgery time was significantly shorter for OAGB (168 ± 7.2 vs. 201 ± 6.8 min). Perioperative complication rates were not significantly (ns) different between RYGB and OAGB. Total body weight loss (TBWL) in RYGB and OAGB was 18 ± 2.2% and 18 ± 1.9% (12 months) and 18 ± 3.0% and 23 ± 2.6% (24 months; ns), respectively. Length of (individualized) biliopancreatic limb (BPL) correlated significantly with weight loss. Remission rates after 12 months of RYGB and OAGB for arterial hypertension (aHt) were 89% and 92%, for obstructive sleep apnea (OSAS) 56% and 82%, for Type 2 diabetes mellitus (T2DM) 100% and 92%, for osteoarthritis 64% and 85% and for GERD 89% versus 87% (ns), respectively. Nutritional deficiencies were comparable in RYGB (n = 11) and OAGB (n = 14) group (ns). CONCLUSION: Both RYGB and OAGB are effective conversional procedures after SG, leading to comparable TBWL, BMI-loss and high remission rates of comorbidities including GERD. Significantly shorter operation times were in favor of OAGB. BPL, which was longer in OAGB was significantly related to higher %TBWL and %BMI-loss compared to RYGB.

Percutaneous transhepatic biliary drainage (PTBD) in patients with dilated vs. nondilated bile ducts: technical considerations and complications.

OBJECTIVES: The aim of this study was to compare success, technical complexity, and complication rates of percutaneous transhepatic biliary drainage (PTBD) in patients with dilated vs. nondilated bile ducts. METHODS: In a retrospective analysis, we evaluated all consecutive PTBD performed in our department over a period of 5 years. Technical success, technical data (side, fluoroscopy time, radiation dose, amount of contrast media, use of disposable equipment), procedure-related complications and peri-interventional mortality were compared for patients with dilated vs. non-dilated bile ducts. Independent t test and χ2 test were used to evaluate the statistical significance. RESULTS: A total of 253 procedures were performed on 187 patients, of whom 101/253 had dilated bile ducts and 152/253 not. In total, 243/253 procedures were successful. PTBD was significantly more often successful in patients with dilated vs. nondilated bile ducts (150/153 vs. 93/101; p 0.02). Overall complication rate (13%) did not differ significantly between patients with dilated vs. nondilated bile ducts. Procedures in patients with normal, nondilated bile ducts were associated with a significantly higher rate of post-interventional bleeding (5/101 vs. 0/152). Mean fluoroscopy time (42:36 ± 35:39 h vs. 30:28 ± 25:10 h; p 0.002) and amount of contrast media (66 ± 40 ml vs. 52 ± 24 ml; p 0.07) or use of disposables were significantly higher in patients with nondilated ducts. A significantly lower fluoroscopy time and amount of contrast medium were used in left hepatic PTBD. CONCLUSION: Despite the higher technical complexity, PTBD with nondilated bile ducts was associated with similar overall complication rates but higher bleeding complications compared with PTBD with dilated bile ducts. KEY POINTS: • PTBD was associated with similar overall complication rates in patients with dilated vs. nondilated bile ducts. • Although overall complication rates were low, PTBD in patients with nondilated bile ducts was associated with a higher incidence of post-interventional bleeding. • PTBD in patients with nondilated bile ducts is technically more complex.

Clinical value and limitations of the preoperative C-reactive-protein-to-albumin ratio in predicting post-operative morbidity and mortality after deceased-donor liver transplantation: a retrospective single-centre study.

Liver transplantation is still associated with a high risk of severe complications and post-operative mortality. This study examines the predictive value of the preoperative C-reactive-protein-to-albumin ratio (CAR) regarding perioperative morbidity and mortality in deceased-donor liver transplantation (DDLT) recipients. In total, 390 DDLT recipients between 05/2010 and 03/2020 were eligible. Predictive abilities of CAR were examined through receiver operating characteristic curve (ROC) analyses. Groups were compared using parametric and non-parametric tests as appropriate. Independent risk factors for morbidity and mortality were identified using uni- and multivariable logistic regression analyses. A good predictive ability for CAR was shown regarding perioperative morbidity (comprehensive complication index ≥75, Clavien-Dindo score ≥4a) and 12-month mortality, with an ideal cut-off of CAR = 26%. Patients with CAR>26% had significantly higher median CCI scores (60 vs. 43, P < 0.001), longer intensive care unit (ICU, 5 vs. 4 days, P < 0.001) and hospital (28 vs. 21 days, P < 0.001) stays and higher 12-month mortality rates (20% vs 6%, P < 0.001). Multivariable analyses identified CAR>26%, pre-OLT inpatient hospitalization (including ICU) and post-operative red blood cell transfusions as independent predictors of severe cumulative morbidity (CCI≥75). Preoperative CAR might be a reliable additional tool to predict perioperative morbidity and mortality in DDLT recipients.

Prognostic evaluation of HCC patients undergoing surgical resection: an analysis of 8 different staging systems.

PURPOSE: No consensus exists regarding the most appropriate staging system to predict overall survival (OS) for hepatocellular carcinoma (HCC) in surgical candidates. Thus, we aimed to determine the prognostic ability of eight different staging systems in a European cohort of patients undergoing liver resection for HCC. METHODS: Patients resected for HCC between 2010 and 2019 at our institution were analyzed with Kaplan-Meier and Cox regression analyses. Likelihood ratio (LR) χ2 (homogeneity), linear trend (LT) χ2 (discriminatory ability), and Akaike Information Criterion (AIC, explanatory ability) were used to determine the staging system with the best overall prognostic performance. RESULTS: Liver resection for HCC was performed in 160 patients. Median OS was 39 months (95% confidence interval (CI): 32-46 months) and median RFS was 26 months (95% CI: 16-34 months). All staging systems (BCLC, HKLC, Okuda, CLIP, ITA.LI.CA staging and score, MESH, and GRETCH) showed significant discriminatory ability regarding OS, with ITA.LI.CA score (LR χ2 30.08, LT χ2 13.90, AIC 455.27) and CLIP (LR χ2 28.65, LT χ2 18.95, AIC 460.07) being the best performing staging systems. CONCLUSIONS: ITA.LI.CA and CLIP are the most suitable staging system to predict OS in European HCC patients scheduled for curative-intent surgery.

Evaluation of NAFLD and fibrosis in obese patients - a comparison of histological and clinical scoring systems.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a frequent condition in obese patients and regularly progresses to non-alcoholic steatohepatitis (NASH) and subsequent cirrhosis. Histologic evaluation is the gold standard for grading and staging, but invasive biopsies are associated with obvious risks. The aim of this study was to evaluate different non-invasive tools for screening of NAFLD and fibrosis in obese patients. METHODS: In a prospective cohort study liver specimens of 141 patients were taken during bariatric surgery. Serological parameters and clinical data were collected and the following scores calculated: NASH clinical scoring system (NCS), aspartate aminotransferase to platelet ratio index (APRI), FIB-4 as well as NAFLD fibrosis score (NFS). Liver function capacity was measured preoperatively by LiMAx test (enzymatic capacity of cytochrome P450 1A2). Intraoperative liver biopsies were classified using NAFLD activity score (NAS) and steatosis, activity and fibrosis (SAF) score. RESULTS: APRI was able to differentiate between not NASH and definite NASH with a sensitivity of 74% and specificity of 67% (AUROC 0.76). LiMAx and NCS also showed significant differences between not NASH and definite NASH. No significant differences were found for NFS and Fib-4. APRI had a high sensitivity (83%) and specificity (76%) in distinguishing fibrosis from no fibrosis (AUROC = 0.81). NCS and Fib-4 also revealed high AUROCs (0.85 and 0.67), whereas LiMAx and NFS did not show statistically significant differences between fibrosis stages. Out of the patients with borderline NASH in the histologic NAS score, 48% were classified as NASH by SAF score. CONCLUSIONS: APRI allows screening of NAFLD as well as fibrosis in obese patients. This score is easy to calculate and affordable, while conveniently only using routine clinical parameters. Using the NAS histologic scoring system bears the risk of underdiagnosing NASH in comparison to SAF score.

Influence of peritoneal carcinomatosis on perioperative outcome in palliative gastric bypass for malignant gastric outlet obstruction - a retrospective cohort study.

BACKGROUND: Malignant gastric outlet obstruction (GOO) is commonly associated with the presence of peritoneal carcinomatosis (PC) and preferably treated by surgical gastrojejunostomy (GJJ) in patients with good performance. Here, we aim to investigate the role of PC as a risk factor for perioperative morbidity and mortality in patients with GOO undergoing GJJ. METHODS: Perioperative data of 72 patients with malignant GOO who underwent palliative GJJ at our institution between 2010 and 2019 were collected within an institutional database. To compare perioperative outcomes of patients with and without PC, extensive group analyses were carried out. RESULTS: A set of 39 (54.2%) patients was histologically diagnosed with concomitant PC while the remaining 33 (45.8%) patients showed no clinical signs of PC. In-house mortality due to surgical complications was significantly higher in patients with PC (9/39, 23.1%) than in patients without PC (2/33, 6.1%, p = .046). Considerable differences were observed in terms of surgical complications such as anastomotic leakage rates (2.8% vs. 0%, p = .187), delayed gastric emptying (33.3% vs. 15.2%, p = .076), paralytic ileus (23.1% vs. 9.1%, p = .113), and pneumonia (17.9% vs. 12.1%, p = .493) without reaching the level of statistical significance. CONCLUSIONS: PC is an important predictor of perioperative morbidity and mortality patients undergoing GJJ for malignant GOO.

ALPPS versus two-stage hepatectomy for colorectal liver metastases--a comparative retrospective cohort study.

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and two stage hepatectomy with inter-stage portal vein embolization (TSH/PVE) are surgical maneuvers applied in patients with advanced malignancies considered unresectable by means of conventional liver surgery. The aim of this report is to compare the oncologic outcome and technical feasibility of ALPPS and TSH/PVE in the scenario of colorectal liver metastases (CRLM). METHODS: All consecutive patients who underwent either ALPPS or TSH/PVE for CRLM between 2011 and 2017 in one hepatobiliary center were analyzed and compared regarding perioperative and long-term oncologic outcome. RESULTS: A cohort of 58 patients who underwent ALPPS (n = 21) or TSH/PVE (n = 37) was analyzed. The median overall survival (OS) was 28 months and 34 months after ALPPS and TSH/PVE (p = 0.963), respectively. The median recurrence-free survival (RFS) was higher following ALPPS with 19 months than following TSH/PVE with 10 months, but marginally failed to achieve statistical significance (p = 0.05). There were no differences in morbidity and mortality after stages 1 and 2. Patients undergoing ALPPS due to insufficient hypertrophy after TSH/PVE (rescue-ALPPS) displayed similar oncologic outcome as patients treated by conventional ALPPS or TSH/PVE (p = 0.971). CONCLUSIONS: ALPPS and TSH/PVE show excellent technical feasibility and comparable long-term oncologic outcome in CRLM. Rescue ALPPS appears to be a viable option for patients displaying insufficient hypertrophy after a TSH/PVE approach.

The role of ALPPS in intrahepatic cholangiocarcinoma.

PURPOSE: Surgical resection constitutes the mainstay of curative treatment for intrahepatic cholangiocarcinoma (iCCA). Complete tumor clearance can only be achieved with extended liver resections and as such, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) may facilitate surgical resectability. The present study aims to evaluate the technical feasibility and oncologic outcome of ALPPS in iCCA. METHODS: A set of 14 patients who underwent ALPPS in a single center between 2011 and 2017 were statistically analyzed for perioperative and oncologic outcome. RESULTS: Of all patients undergoing stage 1 of ALPPS, 12 (86%) patients were subsequently completed in stage 2 surgery. Patients who completed the ALPPS procedure showed a median overall survival (OS) of 4.2 years and a 3-year survival of 64%. Individuals without lymphatic metastases (n = 7) were all alive 1 year after surgery and if deceased, they died more than 4 years after surgery, while no patient with lymphatic metastases (n = 5) was alive 1 year after surgery. CONCLUSION: This is the largest single-center experience of ALPPS in iCCA currently available in the literature showing excellent technical feasibility and encouraging overall survival in these patients.

A Newly Established Murine Cell Line as a Model for Hepatocellular Cancer in Non-Alcoholic Steatohepatitis.

Non-alcoholic steatohepatitis (NASH) has become a major risk factor for hepatocellular cancer (HCC) due to the worldwide increasing prevalence of obesity. However, the pathophysiology of NASH and its progression to HCC is incompletely understood. Thus, the aim of this study was to generate a model specific NASH-derived HCC cell line. A murine NASH-HCC model was conducted and the obtained cancer cells (N-HCC25) were investigated towards chromosomal aberrations, the expression of cell type-specific markers, dependency on nutrients, and functional importance of mTOR. N-HCC25 exhibited several chromosomal aberrations as compared to healthy hepatocytes. Hepatocytic (HNF4), EMT (Twist, Snail), and cancer stem cell markers (CD44, EpCAM, CK19, Sox9) were simultaneously expressed in these cells. Proliferation highly depended on the supply of glucose and FBS, but not glutamine. Treatment with a second generation mTOR inhibitor (KU-0063794) resulted in a strong decrease of cell growth in a dose-dependent manner. In contrast, a first generation mTOR inhibitor (Everolimus) only slightly reduced cell proliferation. Cell cycle analyses revealed that the observed growth reduction was most likely due to G1/G0 cell cycle arrest. These results indicate that N-HCC25 is a highly proliferative HCC cell line from a NASH background, which might serve as a suitable in vitro model for future investigations of NASH-derived HCC.

Prognostic factors of disease-free and overall survival in patients with hepatocellular carcinoma undergoing partial hepatectomy in curative intent.

PURPOSE: Tumor recurrence after liver resection continues to pose a major problem in hepatocellular carcinoma (HCC). Here we aimed to evaluate prognostic markers for disease-free (DFS) and overall survival (OS) in HCC-patients who underwent liver resection in curative intent. Additionally, we investigated the effects of HCC-recurrence in a subgroup of patients. METHODS: Between 2010 and 2016, 111 patients underwent surgical resection for HCC at our institution. A subgroup of 50 patients showed tumor recurrence (n = 50) during follow-up. The associations of DFS and OS with histopathologic characteristics were assessed using univariable and multivariable Cox regression analyses. RESULTS: Median DFS was 31 months and median OS was 27 months. Milan criteria (p = 0.045), macrovascular invasion (p = 0.044) and UICC tumor stage (p = 0.003) were independently associated with DFS while macrovascular invasion (p = 0.001) and MELD score (p = 0.010) were independently associated with OS. Tumor recurrence did not show an association with OS (p = 0.228). However, patients with HCC-recurrence who underwent repeat-surgical or interventional treatment showed improved OS compared to patients treated with palliative or sorafenib treatment alone (OS 18 months vs. 2 months; p < 0.001). CONCLUSION: Tumor recurrence alone is not associated with poor oncological outcome and repeat liver resections as well as local-ablative procedures may help to improve OS in HCC.

Influence of Telomere Length in Hepatocytes on Liver Regeneration after Partial Hepatectomy in Rats.

BACKGROUND: The aim of this study was to investigate telomere length in hepatocytes as a biomarker for liver regeneration after partial hepatectomy (PH) in rats. MATERIALS AND METHODS: Sixty male Wistar rats underwent a 70% PH. One-month-old rats were assigned to group Y (n = 30) and 4-month-old rats were assigned to group O (n = 30). The rats were euthanized, and their livers were then harvested at postoperative day (POD) 1, 2, 3, 4, or 7. Telomere lengths and established parameters for liver regeneration (residual liver weight and levels of proliferating cell nuclear antigen [PCNA], Ki67, and interleukin [IL]-6) were measured. RESULTS: We observed a significant increase in residual liver weight in group Y compared to that in group O (p = 0.001). The levels of Ki67 (p = 0.016), PCNA (p < 0.0001), and IL-6 (p < 0.001) were significantly higher in group Y. Furthermore, the rats in group Y had significantly earlier peak values of Ki67 and PCNA. Telomeres were significantly longer at the time of PH in group Y (p = 0.001). We showed a correlation between telomere length at the day of PH and liver regeneration. Animals with longer telomeres at the time of PH had better liver regeneration (p = 0.015). In group Y, animals with increased liver regeneration (median cut-off: > 122%) did not show any significant difference in telomere length (p = 0.587) compared to rats with regular regeneration (< 122%). However, in the older animals, rats with increased regeneration had significantly longer telomeres (p = 0.019) than rats with regular regeneration. CONCLUSION: Telomere length in rat hepatocytes depends on age, and animals with long telomeres had earlier and better regeneration of healthy liver tissue than rats with short telomeres. Our data confirms that telomere length in rat hepatocytes could be used as a possible predictive marker for liver regeneration, and could help to identify older individuals with a high capacity for hepatic regeneration.

Expression of VEGFR-2 during Liver Regeneration after Partial Hepatectomy in a Bioluminescence Mouse Model.

BACKGROUND: Liver regeneration requires the formation of new blood vessels. Endothelial cell proliferation is stimulated by vascular endothelial growth factor (VEGF) and its receptor tyrosine kinase VEGFR-2. The aim of this study was to investigate VEGFR-2 expression in vivo during liver regeneration after partial hepatectomy (PHx). METHODS: Transgenic VEGFR-2-luc mice were used in which the luciferase reporter gene was under control of the VEGFR-2 promoter. Following 2/3 PHx, the mice underwent in vivo bioluminescence imaging until the 14th postoperative day. Additionally, liver tissue was analyzed by immunohistochemistry, in vitro luminescence assays, and quantitative RT-PCR. RESULTS: In vivo bioluminescence imaging showed a significant increase in VEGFR-2 promoter activity after PHx. Maximum signal was recorded on the 3rd day; 8 days postoperatively the signal intensity decreased significantly. On the 14th day, bioluminescence signal reached almost baseline levels. Immunohistochemistry, quantitative RT-PCR, and in vitro luminescence confirmed a significant increase on the 3rd day following resection. The mRNA expression of VEGFR-2 was significantly higher on day 3 than preoperatively as well as on day 8. CONCLUSION: In vivo bioluminescence imaging with transgenic VEGFR-2-luc mice is feasible and provides a convenient model for noninvasively studying VEGFR-2 expression during liver regeneration. This may facilitate further experiments with modulation of angiogenesis by different substances.

Argon Delays Initiation of Liver Regeneration after Partial Hepatectomy in Rats.

BACKGROUND: The liver can heal up to restitutio ad integrum following damage resulting from various causes. Different studies have demonstrated the protective effect of argon on various cells and organs. To the best of our knowledge, the organ-protective effects of the noble gas argon on the liver have not yet been investigated, although argon appears to influence signal paths that are well-known mediators of liver regeneration. We hypothesized that argon inhalation prior to partial hepatectomy (70%) has a positive effect on the initiation of liver regeneration in rats. METHODS: Partial hepatectomy (70%) with or without inhaled argon (50 vol%) was performed for 1 h. Liver tissue was harvested after 3, 36, and 96 h to analyze the mRNA and protein expression of hepatocyte growth factor (HGF), interleukin-6 (IL-6), tumor necrosis factor-α, and extracellular signal-regulated kinase 1/2. Histological tissue samples were prepared for immunohistochemistry (bromodeoxyuridine [BrdU], Ki-67, and TUNEL) and blood was analyzed regarding the effects of argon on liver function. Statistical analyses were performed using 1-way ANOVA followed by the post hoc Tukey-Kramer test. RESULTS: After 3 h, the primary outcome parameter of hepatocyte proliferation was significantly reduced with argon 50 vol% inhalation in comparison to nitrogen inhalation (BrdU: 15.7 ± 9.7 vs. 7.7 ± 3.1 positive cells/1,000 hepatocytes, p = 0.013; Ki-67: 17.6 ± 13.3 vs. 4.7 ± 5.4 positive cells/1,000 hepatocytes, p = 0.006). This was most likely mediated by significant downregulation of HGF (after 3 h: 5.2 ± 3.2 vs. 2.3 ± 1.0 fold, p = 0.032; after 96 h: 2.1 ± 0.5 vs. 1.3 ± 0.3 fold, p = 0.029) and IL-6 (after 3 h: 43.7 ± 39.6 vs. 8.5 ± 9.2 fold, p = 0.032). Nevertheless, we could detect no significant effect on the weight of the residual liver, liver-body weight ratio, or liver blood test results after argon inhalation. CONCLUSION: Impairment of liver regeneration was apparent after argon 50 vol% inhalation that was most probably mediated by downregulation of HGF and IL-6 in the initial phase. However, the present study was not adequately powered to prove that argon has detrimental effects on the liver. Further studies are needed to evaluate the effects of argon on livers with preexisting conditions as well as on ischemia-reperfusion models.

Comparative study of the effects of terlipressin versus splenectomy on liver regeneration after partial hepatectomy in rats.

BACKGROUND: Post-hepatectomy liver failure as a result of insufficient liver remnant is a feared complication in liver surgery. Efforts have been made to find new strategies to support liver regeneration. The aim of this study was to investigate the effects of terlipressin versus splenectomy on postoperative liver function and liver regeneration in rats undergoing 70% partial hepatectomy. METHODS: Seventy-two male Wistar rats were randomly assigned into three groups (n=24 in each group): 70% partial hepatectomy as control (PHC), 70% partial hepatectomy with splenectomy (PHS) or 70% partial hepatectomy with a micropump for terlipressin administration (PHT). Eight rats in each group were sacrificed on postoperative day (POD) 1, 3 and 7. To assess liver regeneration, immunohistochemical analysis of liver tissue using bromodeoxyuridine (BrdU) and Ki-67 labeling was performed. Portal venous pressure, serum concentrations of creatinine, urea, albumin, bilirubin and prothrombin time as well as liver-, body-weight and their ratio were determined on POD 1, 3 and 7. RESULTS: The liver-, body-weight and their ratio were not statistically different among the groups. On POD 1, 3 and 7 portal venous pressure in the intervention groups (PHT: 8.13±1.55, 10.38±1.30, 6.25±0.89 cmH2O and PHS: 7.50±0.93, 8.88±2.42, 5.75±1.04 cmH2O) was lower compared to the control group (PHC: 8.63±2.06, 10.50±2.45, 6.50±2.67 cmH2O). Hepatocyte proliferation in the intervention groups was delayed, especially after splenectomy on POD 1 (BrdU: PHS vs PHC, 20.85%±13.05% vs 28.11%±10.10%; Ki-67, 20.14%±14.10% vs 23.96%±11.69%). However, none of the differences were statistically significant. CONCLUSIONS: Neither the administration of terlipressin nor splenectomy improved liver regeneration after 70% partial hepatectomy in rats. Further studies assessing the regulation of portal venous pressure as well as extended hepatectomy animal models and liver function tests will help to further investigate mechanisms of liver regeneration.

Grade of donor liver microvesicular steatosis does not affect the postoperative outcome after liver transplantation.

BACKGROUND: The potential effect of graft steatosis on the postoperative liver function is discussed controversially. The present study aimed to evaluate the effect of the donor liver microvesicular steatosis on the postoperative outcome after liver transplantation. METHODS: Ninety-four patients undergoing liver transplantation at the University Hospital Aachen were included in this study. The patient cohort was divided into three groups according to the grade of microvesicular steatosis (MiS): MiS <30% (n=27), MiS 30%-60% (n=41) and MiS >60% (n=26). The outcomes after liver transplantation were evaluated, including the 30-day and 1-year patient and graft survival rates and the incidences of early allograft dysfunction (EAD) and primary nonfunction (PNF). RESULTS: The incidences of EAD and PNF did not differ significantly between the groups. We observed 5 cases of PNF, one occurred in the MiS <30% group and 4 in the MiS 30%-60% group. The 30-day and 1-year graft survivals did not differ significantly between groups. The 30-day patient survival rates were 100% in all groups. The 1-year patient survival rates were 94.4% in the MiS <30% group, 87.9% in the MiS 30%-60% group and 90.9% in the MiS >60% group. CONCLUSION: Microvesicular steatosis of donor livers has no negative effect on the postoperative outcome after liver transplantation.