Liver failure after partial hepatic resection: definition, pathophysiology, risk factors and treatment

N-acetylcysteine administration does not improve patient outcome after liver resection

BACKGROUND

Post-operative hepatic dysfunction is a major cause of concern when undertaking a liver resection. The generation of reactive oxygen species (ROS) as a result of hepatic ischaemia/reperfusion (I/R) injury can result in hepatocellular injury. Experimental evidence suggests that N-acetylcysteine may ameliorate ROS-mediated liver injury.

METHODS

A cohort of 44 patients who had undergone a liver resection and receiving peri-operative N-acetylcysteine (NAC) were compared with a further cohort of 44 patients who did not. Liver function tests were compared on post-operative days 1, 3 and 5. Peri-operative outcome data were retrieved from a prospectively maintained database within our unit.

RESULTS

Administration of NAC was associated with a prolonged prothrombin time on the third post-operative day (18.4 versus 16.4 s; P = 0.002). The incidence of grades B and C liver failure was lower in the NAC group although this difference did not reach statistical significance (6.9% versus 14%; P = 0.287). The overall complication rate was similar between groups (32% versus 25%; P = ns). There were two peri-operative deaths in the NAC group and one in the control group (P = NS).

CONCLUSION

In spite of promising experimental evidence, this study was not able to demonstrate any advantage in the routine administration of peri-operative NAC in patients undergoing a liver resection.

Physiological and biochemical basis of clinical liver function tests: a review

OBJECTIVE

To review the literature on the most clinically relevant and novel liver function tests used for the assessment of hepatic function before liver surgery.

BACKGROUND

Postoperative liver failure is the major cause of mortality and morbidity after partial liver resection and develops as a result of insufficient remnant liver function. Therefore, accurate preoperative assessment of the future remnant liver function is mandatory in the selection of candidates for safe partial liver resection.

METHODS

A MEDLINE search was performed using the key words "liver function tests," "functional studies in the liver," "compromised liver," "physiological basis," and "mechanistic background," with and without Boolean operators.

RESULTS

Passive liver function tests, including biochemical parameters and clinical grading systems, are not accurate enough in predicting outcome after liver surgery. Dynamic quantitative liver function tests, such as the indocyanine green test and galactose elimination capacity, are more accurate as they measure the elimination process of a substance that is cleared and/or metabolized almost exclusively by the liver. However, these tests only measure global liver function. Nuclear imaging techniques ((99m)Tc-galactosyl serum albumin scintigraphy and (99m)Tc-mebrofenin hepatobiliary scintigraphy) can measure both total and future remnant liver function and potentially identify patients at risk for postresectional liver failure.

CONCLUSIONS

Because of the complexity of liver function, one single test does not represent overall liver function. In addition to computed tomography volumetry, quantitative liver function tests should be used to determine whether a safe resection can be performed. Presently, (99m)Tc-mebrofenin hepatobiliary scintigraphy seems to be the most valuable quantitative liver function test, as it can measure multiple aspects of liver function in, specifically, the future remnant liver.

Kinetics of liver function tests after a hepatectomy for colorectal liver metastases predict post-operative liver failure as defined by the International Study Group for Liver Surgery

BACKGROUND

Post-hepatectomy liver failure (PHLF) has been defined by the International Study Group for Liver Surgery (ISGLS). The purpose of the present study was to examine the kinetics of conventional liver function tests (LFT) after a major liver resection and is the first to examine their utility in predicting PHLF in groups defined by the ISGLS.

METHODS

Consecutive patients undergoing a major liver resection for colorectal liver metastases were stratified into ISGLS groups and their LFT up to 1 year after surgery compared. Receiving-operating characteristic (ROC) analysis of LFT identified optimal thresholds in predicting category C liver failure.

RESULTS

In total, 32, 22 and 19 patients belonged to ISGLS groups A, B and C, respectively. The median international normalized ratio (INR) and bilirubin values on post-operative days 1, 3, 5 and 7 were significantly different among the groups (all P-values <0.05). ROC analysis of day 1 INR (AUC 0.813) and day 5 bilirubin (AUC 0.798) revealed thresholds of 1.35 and 52 μmol/l to have sensitivities of 85% and 81% and specificities of 63% and 73%, respectively, to predict group C liver failure.

DISCUSSION

Post-operative LFT after a major liver resection differs significantly among the three ISGLS groups. Thresholds of bilirubin and INR can be used to identify patients who are at a maximum risk of complications.

Effect of bone marrow mesenchymal stem cells on hepatocellular carcinoma in microcirculation

This study aims t explore the effect and application of bone marrow mesenchymal stem cells (BMSCs) on hepatocellular carcinoma in microcirculation by observing the angiogenesis of hepatocellular carcinoma in transplanted area. BMSCs were isolated and cultured primarily using the method of whole bone marrow culture and identifying surface antigens of third-generation bone marrow-derived mesenchymal stem cells using flow cytometry. Hepatoma cells cultured with BMSCs-conditioned medium (BMSCs-CM) were assayed using the cell proliferation rate of the MTT method. Nude mice were divided into control group (group A), BMSCs cell transplantation group (group B), HepG-2 cell group (group C), and combined BMSCs and HepG-2 cell cotransplanted group (group D). The result showed that the microvascular density was not significantly different in groups A and B. However, the microvascular density at 14 days was higher than 0 day in group C (P < 0.05). In group D, the microvascular density at 14 days was higher than that of 7 and 0 days (P < 0.05) and 7 days was higher than 0 days (P < 0.05). It was showed that the microvascular density did not get significant difference at 0 and 7 days in the four groups (P > 0.05). But the microvascular density of group C was higher than groups A and B at 14 days (P < 0.05), group D was higher than groups A and B at 14 days (P < 0.05) and group D was higher than group C at 14 days (P < 0.05). BMSCs could promote the growth of microvascular in hepatoma cells in a transplanted area.

Liver manipulation during liver surgery in humans is associated with hepatocellular damage and hepatic inflammation

BACKGROUND

Manipulation of the liver during liver surgery results in profound hepatocellular damage. Experimental data show that mobilization-induced hepatocellular damage is related to hepatic inflammation. To date, information on this link in humans is lacking. As it is possible to modulate inflammation, it is clinically relevant to unravel this relationship.

AIM

This observational study aimed to establish the association between liver mobilization and hepatic inflammation in humans.

METHODS

Consecutive patients requiring mobilization of the right hemi-liver during liver surgery were studied. Plasma samples and liver biopsies were collected prior to and directly after mobilization and after transection of the liver. Hepatocellular damage was assayed by liver fatty acid-binding protein (L-FABP) and aminotransferase levels. Hepatic inflammation was determined by (a) immunohistochemical identification of myeloperoxidase (MPO) and CD68- positive cells and (b) hepatic gene expression of inflammatory and cell adhesion molecules (IL-1β, IL-6, IL-8, VCAM-1 and ICAM-1).

RESULTS

A total of 25 patients were included. L-FABP levels increased significantly during mobilization (301 ± 94 ng/ml to 1599 ± 362 ng/ml, P = 0.008), as did ALAT levels (36 ± 5 IU/L to 167 ± 21 IU/L, P < 0.001). A significant increase in MPO (P = 0.001) and CD68 (P = 0.002) positive cells was noticed in the liver after mobilization. The number of MPO-positive cells correlated with the duration of mobilization (Pearson correlation=0.505, P = 0.033). Hepatic gene expression of pro-inflammatory cytokines IL-1β and IL-6, chemo-attractant IL-8 and adhesion molecule ICAM-1 increased significantly during liver manipulation.

CONCLUSIONS

Liver mobilization is associated with hepatocellular damage and liver inflammation, as shown by infiltration of inflammatory cells and upregulation of genes involved in acute inflammation.

Acute Liver Failure following Hepatic Resection: Incidence, Presentation, Prevention and Management in ICU

The incidence of liver failure following liver resection has been reported to be between 8–32%, depending on the number of segments resected, the health of the patient and the incidence of hepatic ischaemic/reperfusion injury. This article outlines the evidence surrounding classification, prevention and management of this condition.

Extended preoperative chemotherapy, extent of liver resection and blood transfusion are predictive factors of liver failure following resection of colorectal liver metastasis

AIM

The aim of this study was to determine the incidence and prognostic factors of postoperative liver failure in patients submitted to liver resection for colorectal metastases.

METHOD

Patients with CLM who underwent hepatectomy from 1998 to 2009 were included in retrospective analysis. Postoperative liver failure was defined using either the 50-50 criteria or the peak of serum bilirubin level above 7 mg/dL independently.

RESULTS

Two hundred and nine (209) procedures were performed in 170 patients. 120 surgeries were preceded by chemotherapy within six months. The overall morbidity rate was 53.1% and 90-day mortality was 2.3%. Postoperative liver failure occurred in 10% of all procedures, accounting for a mortality rate of 9.5% among this group of patients. In multivariate analysis, extent of liver resection, need of blood transfusion and more than eight preoperative chemotherapy cycles were independent prognostic factors of postoperative liver insufficiency. This complication was not related with the chemotherapy regimen used.

CONCLUSION

We conclude that postoperative liver failure has a relatively low incidence (10%) after CLM resection, but a remarkable impact on postoperative mortality rate. The amount of liver resected, the need of blood transfusion and extended preoperative chemotherapy are independent predictors of its occurrence and this knowledge can be used to prevent postoperative liver failure in a multidisciplinary approach.

Assessment of hepatic function with Gd-EOB-DTPA-enhanced hepatic MRI

Assessment of hepatic function is essential in determining the prognosis and clinical management of a patient who has chronic liver disease or undergoes liver surgery. For a patient with locally varying hepatic parenchymal abnormalities, a regional assessment of hepatic function mapped onto hepatic anatomy is clinically more meaningful than conventional global metrics of hepatic function. Of late, hepatic magnetic resonance imaging has been increasingly used because of its superb tissue contrast and delineation of hepatic morphology and underlying abnormalities. The introduction of hepatocyte-specific contrast agents such as Gd-EOB-DTPA allows us to view not only the hepatic anatomy but also assess regional hepatic function. In this article, we review and discuss recently published studies that used Gd-EOB-DTPA-enhanced magnetic resonance imaging to evaluate hepatic function.

Severity of portal hypertension and prediction of postoperative liver failure after liver resection in patients with Child–Pugh grade A cirrhosis

Background

Patients with Child–Pugh grade A cirrhosis and clinical evidence of portal hypertension are likely to develop posthepatectomy liver failure (PHLF). Whether such patients are suitable candidates for partial hepatectomy is controversial. This study explored the impact of portal venous pressure (PVP) on PHLF and the possibility of stratifying patients with Child–Pugh grade A cirrhosis for risk of PHLF using clinical data alone.

Methods

Between April 2009 and May 2011, consecutive patients who underwent partial hepatectomy for hepatocellular carcinoma and intraoperative measurement of PVP were included in this prospective study. Using signs of clinically significant portal hypertension (CSPH), patients with Child–Pugh grade A cirrhosis were subclassified into three groups: no, mild and severe CSPH. Risk factors for PHLF were subjected to univariable and multivariable analysis, and receiver operating characteristic (ROC) curve analysis.

Results

Sixty-seven (35·3 per cent) of 190 patients developed PHLF, which was persistent in 12 patients (6·3 per cent). Four patients (2·1 per cent) died from PHLF within 3 months of surgery. Multivariable analysis showed both PVP and CSPH to be independent predictors of PHLF (P &lt; 0·001). PVP values, incidence of PHLF and persistent PHLF were significantly higher in the severe CSPH group than in the other two groups (P &lt; 0·001). Severe CSPH (odds ratio 27·68, P = 0·005) and a preoperative neutrophil : lymphocyte ratio (NLR) of 2·8 or above (odds ratio 49·75, P = 0·002) were independent factors affecting the incidence of persistent PHLF.

Conclusion

The severity of CSPH, corresponding to different PVP levels, could be used to stratify patients with Child-Pugh grade A cirrhosis and to predict the incidence of PHLF. Patients with severe CSPH or a NLR of 2·8 or above were more likely to develop persistent PHLF after partial hepatectomy.

Inhalation of hydrogen gas reduces liver injury during major hepatotectomy in swine

AIM: To study the effect of H₂ gas on liver injury in massive hepatectomy using the Intermittent Pringle maneuver in swine.

METHODS: Male Bama pigs (n = 14) treated with ketamine hydrochloride and Sumianxin II as induction drugs followed by inhalation anesthesia with 2% isoflurane, underwent 70% hepatotectomy with loss of bleeding less than 50 mL, and with hepatic pedicle occlusion for 20 min, were divided into two groups: Hydrogen-group (n = 7), the pigs with inhalation of 2% hydrogen by the tracheal intubation during major hepatotectomy; Contrast-group (n = 7), underwent 70% hepatotectomy without inhalation of hydrogen. Hemodynamic changes and plasma concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and malondialdehyde (MDA) in liver tissue were measured at pre-operation, post-hepatotectomy (PH) 1 h and 3 h. The apoptosis and proliferating cell nuclear antigen (PCNA) expression in liver remnant were evaluated at PH 3 h. Then we compared the two groups by these marks to evaluate the effect of the hydrogen in the liver injury during major hepatotectomy with the Pringle Maneuver in the swine.

RESULTS: There were no significant differences in body weight, blood loss and removal liver weight between the two groups. There was no significant difference in changes of portal vein pressure between two groups at pre-operation, PH 30 min, but in hydrogen gas treated-group it slightly decrease and lower than its in Contrast-group at PH 3 h, although there were no significant difference (P = 0.655). ALT and AST in Hydrogen-group was significantly lower comparing to Contrast-group (P = 0.036, P = 0.011, vs P = 0.032, P = 0.013) at PH 1 h and 3 h, although the two groups all increased. The MDA level increased between the two group at PH 1 h and 3 h. In the hydrogen gas treated-group, the MDA level was not significantly significant at pre-operation and significantly low at PH 1 h and 3 h comparing to Contrast-group (P = 0.0005, P = 0.0004). In Hydrogen-group, the HA level was also significantly low to Contrast-group (P = 0.0005, P = 0.0005) although the two groups all increased at PH 1 h and 3 h. The expression of cluster of differentiation molecule 31 molecules Hydrogen-group was low to Contrast-group. However, PCNA index (%) was not statistically significant between the two groups (P = 0.802). Microphotometric evaluation of apoptotic index (AI) in terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-stained tissue after hepatotectomy for 3h, the AI% level in the hydrogen was significantly low to Contrast-group (P = 0.012). There were no significant difference between Hydrogen-group and Contrast-group at pre-operation (P = 0.653, P = 0.423), but after massive hepatotectomy, the TNF-α and IL-6 levels increase, and its in Hydrogen-group was significantly low compared with Contrast-group (P = 0.022, P = 0.013, vs P = 0.016, P = 0.012), respectively. Hydrogen-gas inhalation reduce levels of these markers and relieved morphological liver injury and apoptosis.

CONCLUSION: H₂ gas attenuates markedly ischemia and portal hyperperfusion injury in pigs with massive hepatotectomy, possibly by the reduction of inflammation and oxidative stress, maybe a potential agent for treatment in clinic.

Risk maps for liver surgery

PURPOSE

Optimal display of surgical planning data in the operating room is challenging. In liver surgery, an expressive and effective intraoperative visualization of 3D planning models is still a pressing need. The objective of this work is to visualize surgical planning information using a map display.

METHODS

An approach for risk analysis and visualization of planning models is presented which provides relevant information at a glance without the need for user interaction. Therefore, we present methods for the identification and classification of critical anatomical structures in the proximity of a preoperatively planned resection surface. Shadow-like distance indicators are introduced to encode the distance from the resection surface to these critical structures on a risk map. The work is demonstrated with examples in liver resection surgery and evaluated within two user studies.

RESULTS

The results of the performed user studies show that the proposed visualization techniques facilitate the process of risk assessment in liver resection surgery and might be a valuable extension to surgical navigations system.

CONCLUSION

The approach provides a new and objective basis for the assessment of risks during liver surgery and has the potential to improve the outcome of surgical interventions.

Liver function testing with nuclear medicine techniques is coming of age

Liver function is a broad term, as the organ participates in a multitude of different physiological and biochemical processes, including metabolic, synthetic, and detoxifying functions. However, it is the function of the hepatocyte that is central to sustaining normal life and dealing with disease states. When the liver begins to fail in severely ill patients, it forecasts a terminal outcome. However, unlike the glomerular filtration rate which clearly quantifies the key renal function, at most practice sites, there is no clinically available quantitative test for liver function. Although it is commonplace to assess indirect evidence of that function (by measuring blood levels of its end products and by-products) and to detect an acute injury (by following rising transaminases), a widely available test that would directly measure hepatocellular function is lacking. This article reviews current knowledge on liver function studies and focuses on those nuclear medicine tests available to study the whole liver and regional liver function. The clinical application driving these tests, prediction of remnant liver function after partial hepatectomy for primary liver malignancy or metastatic disease, is addressed here in detail. The test was recently validated for this specific application and was shown to be better than the current standard of practice (computed tomography volumetry), particularly in patients with hepatic comorbidities like cirrhosis, steatosis, or cholestasis. Furthermore, early assessment of regional liver function increase after preoperative portal vein embolization becomes possible with this technology. The limiting factor to a wider acceptance of this test is based on the lack of clinical software that would allow calculation of liver function parameters. This article provides information that enables a clinical nuclear medicine facility to provide this test using readily available equipment. Furthermore, it addresses emerging clinical applications that are under investigation.

Automated liver volumetry in orthotopic liver transplantation using multiphase acquisitions on MDCT

OBJECTIVE

The aim of this study was to test a new automated hepatic volumetry technique by comparing the accuracies and postprocessing times of manual and automated liver volume segmentation methods in a patient population undergoing orthotopic liver transplantation so that liver volume could be determined on pathology as the standard of reference.

CONCLUSION

Both manual and automated multiphase MDCT-based volume measurements were strongly correlated to liver volume (Pearson correlation coefficient, r = 0.87 [p < 0.0001] and 0.90 [p < 0.0001], respectively). Automated multiphase segmentation was significantly more rapid than manual segmentation (mean time, 16 ± 5 [SD] and 86 ± 3 seconds, respectively; p = 0.01). Overall, automated liver volumetry based on multiphase CT acquisitions is feasible and more rapid than manual segmentation.

Prediction of recurrence after curative resection of hepatocellular carcinoma using liver stiffness measurement (FibroScan®)

BACKGROUND

The purpose of this study was to investigate whether preoperative liver stiffness measurement (LSM) can predict recurrence after curative resection of hepatocellular carcinoma (HCC). LSM using FibroScan(®) can assess the severity of liver fibrosis, which is significantly associated with recurrence after curative resection of HCC.

METHODS

Between February 2006 and March 2009, 133 patients who underwent preoperative LSM and curative resection for HCC were enrolled in this prospective study. LSM values were analyzed for association with recurrence, together with other clinical variables.

RESULTS

The mean age of the patients (117 men and 16 women) was 57 years. During the follow-up period (median, 25.0 (range, 3.0-54.6) months), HCC recurred in 62 (46.6 %) patients. In multivariate analysis, together with satellite nodule and Edmonson-Steiner grade III-IV, LSM was selected as an independent predictor of recurrence (P < 0.05; hazard ratio, 1.034; 95 % confidence interval, 1.007-1.061). When the study population was stratified into two groups using the optimal cutoff value (13.4 kPa) that maximized the sum of sensitivity (64.7 %) and specificity (76.1 %) from time-dependent receiver operating characteristic curves (area under the receiver operating characteristic curve = 0.676), patients with LSM values >13.4 kPa were at a significantly greater risk for recurrence with a hazard ratio of 1.925 (P = 0.01; 95 % confidence interval, 1.17-3.168) compared with those with LSM values ≤ 13.4 kPa.

CONCLUSIONS

Our data suggest that LSM can be a useful predictor of recurrence after curative resection of HCC.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

Case report: Percutaneous treatment of multiple honeycomb-like liver hydatid cysts (type III CE2, according to WHO classification)

Percutaneous treatment has been developing as a reliable and effective alternative to surgery in the treatment of liver hydatid cysts. However, percutaneous treatment is strongly recommended only for some types of hydatid cysts (types I and II). We report a patient with type III (CE2, according to the WHO classification) multiple liver hydatid cysts treated with the PAIR (puncture-aspiration-injection-reaspiration) technique. The patient developed a secondary biliary fistula, which ultimately healed.

Matrix metalloproteinase-9 contributes to parenchymal hemorrhage and necrosis in the remnant liver after extended hepatectomy in mice

AIM: To investigate the effect of matrix metalloproteinase-9 (MMP-9) on the remnant liver after massive hepatectomy in the mouse.

METHODS: Age-matched, C57BL/6 wild-type (WT), MMP-9(-/-), and tissue inhibitors of metalloproteinases (TIMP)-1(-/-) mice were used. The mice received 80%-partial hepatectomy (PH). Samples were obtained at 6 h after 80%-PH, and we used histology, immunohistochemical staining, western blotting analysis and zymography to investigate the effect of PH on MMP-9. The role of MMP-9 after PH was investigated using a monoclonal antibody and MMP inhibitor.

RESULTS: We examined the remnant liver 6 h after 80%-PH and found that MMP-9 deficiency attenuated the formation of hemorrhage and necrosis. There were significantly fewer and smaller hemorrhagic and necrotic lesions in MMP-9(-/-) remnant livers compared with WT and TIMP-1(-/-) livers (P < 0.01), with no difference between WT and TIMP-1(-/-) mice. Serum alanine aminotransaminase levels were significantly lower in MMP-9(-/-) mice compared with those in TIMP-1(-/-) mice (WT: 476 ± 83 IU/L, MMP-9(-/-): 392 ± 30 IU/L, TIMP-1(-/-): 673 ± 73 IU/L, P < 0.01). Western blotting and gelatin zymography demonstrated a lack of MMP-9 expression and activity in MMP-9(-/-) mice, which was in contrast to WT and TIMP-1(-/-) mice. No change in MMP-2 expression was observed in any of the study groups. Similar to MMP-9(-/-) mice, when WT mice were treated with MMP-9 monoclonal antibody or the synthetic inhibitor GM6001, hemorrhagic and necrotic lesions were significantly smaller and fewer than in control mice (P < 0.05). These results suggest that MMP-9 plays an important role in the development of parenchymal hemorrhage and necrosis in the small remnant liver.

CONCLUSION: Successful MMP-9 inhibition attenuates the formation of hemorrhage and necrosis and might be a potential therapy to ameliorate liver injury after massive hepatectomy.

Liver epithelial cells proliferate under hypoxia and protect the liver from ischemic injury via expression of HIF-1 alpha target genes

BACKGROUND

The remnant liver after extended liver resection is susceptible to ischemic injury, resulting in the failure of liver regeneration and liver dysfunction. The present study is aimed to investigate the protective role of the liver epithelial cells (LEC), a liver progenitor cell, on hepatocytes with ischemia in vitro and in vivo.

METHODS

LECs were isolated from rats and cultured under hypoxic conditions (2% O(2)). The cell viability and intracellular ATP levels were measured. The activation of hypoxia-inducible factor-1α (HIF-1α) was assessed by immunofluorescence. The expression of pyruvate dehydrogenase kinase-1 (PDK-1), stromal cell-derived factor-1 (SDF-1), and chemokine receptor 4 (CXCR4) were measured. Hepatocytes were treated with SDF-1 or LEC-conditioned medium under hypoxia, and cell viability was assessed. Finally, hemorrhagic shock was induced in rats with in vivo induction of endogenous LECs, and liver damage was assessed.

RESULTS

In LECs, but not in hepatocytes, cellular viability and intracellular ATP levels were maintained, and nuclear translocation of HIF-1α and expression of pyruvate dehydrogenase kinase-1 mRNA were increased under hypoxic culture conditions. LECs express SDF-1, and CXCR4 expression was increased in hepatocytes under hypoxia. The survival of hepatocytes under hypoxic condition was significantly increased after treatment with SDF-1 or LEC-conditioned medium. The protective effect of conditioned medium was impaired by CXCR4 antagonists. In vivo induction of endogenous LECs suppressed elevation of serum AST and ALT levels after hemorrhage shock and ischemia-reperfusion.

CONCLUSION

LECs are resistant to hypoxia and have a protective role for hepatocytes against hypoxia. Our results suggest that induction of endogenous LECs protected the liver from lethal insults by paracrine signaling of SDF-1 and differentiation into parenchymal cells.

Impact of preoperative targeted therapy on postoperative complications after resection of colorectal liver metastases

PURPOSE

The impact of chemotherapy (CTx) on morbidity after liver resection for colorectal metastases (CRC-LM) has been increasingly investigated during recent years. Biologic agents like bevacizumab (BEV) or cetuximab (CET) are now added as "targeted therapy" (TT), also in neoadjuvant settings. Initial series could demonstrate the safety of those regimens in liver resection but data are still scarce. We evaluated the impact of CTx with BEV or CET (CTx + TT) on perioperative morbidity and mortality.

METHODS

Two hundred thirty-seven patients who underwent liver resections for CRC-LM after chemotherapy before surgery since 1999 were included. One hundred eighty-five patients (78%) had preoperative CTx regimen without biologic agents (fluoropyrimidine-, oxaliplatin-, or irinotecan-based) and 52 (22%) had CTx + TT (39 BEV, 11 CET, 2 CET/BEV). After preoperative CTx + TT, a time interval of at least 4-6 weeks and a residual liver volume of >35% before surgery were required.

RESULTS

Hemihepatectomy or more was performed in about half of the patients. The median amount of intraoperatively transfused blood was 0 ml in both groups (p = 0.34). Overall mortality was 1.7% and slightly elevated in patients with CTx + TT (3.8% vs. 1.1%, p = 0.17). Any complication occurred in (CTx + TT vs. CTx) 52% and 46%, respectively (p = 0.47). The rates of liver failure (9.6% vs. 9.7%, p = 0.98), infectious complications such as wound infection (19% vs. 16%, p = 0.62) and abdominal abscess (8% vs. 6.5%, p = 0.71), as well as the rate of relaparotomies (11.5% vs. 7.0%, p = 0.29) showed no significant differences between the groups with TT or without. In multivariate analyses, neither type nor duration of CTx nor the time interval between CTx and surgery showed any influence on complication rates.

CONCLUSIONS

Our data confirm the safety of targeted therapy before liver resection for CRC-LM. This effect may in part be due to our treatment policy (time interval to resection and residual liver volume) after intensive preoperative CTx.

Reappraisal of hepatopancreatoduodenectomy as a treatment modality for bile duct and gallbladder cancer

BACKGROUND

Hepatopancreatoduodenectomy has been performed to achieve radical resection in malignant biliary tumors. We reviewed clinical outcomes to evaluate the clinical feasibility of hepatopancreatoduodenectomy for the treatment of gallbladder and bile duct cancer.

METHODS

Twenty-three patients underwent hepatopancreatoduodenectomy from 1995 to 2007; 10 gallbladder cancer and 13 bile duct cancer. Median follow-up periods were 15.0 months.

RESULTS

R0 resection was performed in 17 of 23 patients (73.9%). Morbidity and mortality rates were 91.3% and 13.0%, respectively. Five-year survival rates were 10.0% for gallbladder cancer and 32.3% for bile duct cancer. Survival more than 3 years was possible for most patients with stage IIA or less, whereas all gallbladder cancer patients with stage III and all bile duct cancer with stage IIB or more died within 2 years. Bile duct cancer patients with pN0 survived longer than those with pN1 (p < 0.001).

CONCLUSIONS

To obtain negative proximal and distal ductal resection margins in the biliary tract cancer, R0 resection and long-term survival can be achieved by hepatopancreatoduodenectomy. However, its adoption in patients with lymph node metastasis or adjacent organ invasion cannot be recommended.

Enhanced recovery for non-colorectal surgery

In recent years the advent of programs for enhanced recovery after major surgery (ERAS) has led to modifications of long-standing and well-established perioperative treatments. These programs are used to target factors that have been shown to delay postoperative recovery (pain, gut dysfunction, immobility) and combine a series of interventions to reduce perioperative stress and organ dysfunction. With due differences, the programs of enhanced recovery are generally based on the preoperative amelioration of the patient’s clinical conditions with whom they present for the operation, on the intraoperative and postoperative avoidance of medications that could slow the resumption of physiological activities, and on the promotion of positive habits in the early postoperative period. Most of the studies were conducted on elective patients undergoing colorectal procedures (either laparotomic or laparoscopic surgery). Results showed that ERAS protocols significantly improved the lung function and reduced the time to resumption of oral diet, mobilization and passage of stool, hospital stay and return to normal activities. ERAS’ acceptance is spreading quickly among major centers, as well as district hospitals. With this in mind, is there also a role for ERAS in non-colorectal operations?

Nutritional aspects in patient undergoing liver resection

In the past two decades, hepatic surgery has achieved important technical breakthroughs resulting in a drastic reduction of the onset of complications and in an improved post-resective survival. Pre-operative nutritional status is one of the key points for the success of a liver resection. Modern surgical achievement such as the development of living-related liver donation, and the possibility to perform more laparoscopic liver resection gave us the opportunity to extend post-operative protocol focused on early intestinal feeding to tumor patients. The aims of this review were to report the current status of the knowledge regarding nutritional aspects in liver resection patients.

Application of multi-slice spiral CT three-dimensional reconstruction technique in liver resection for hepatic carcinoma

Hepatic carcinoma is a very common disease across the world, and hepatic resection is still the best treatment. As the liver has complex anatomy and frequent vascular variations, it is of great importance to obtain some preoperative data, such as the position of liver cancer and its relationship with liver vessels and adjacent structures. Now, three-dimensional reconstruction technique allows to clearly show the relationship of the hepatic artery, portal vein, hepatic vein and tumor with surrounding strctures and accurately calculate the remnant liver volume, providing valuable preoperative imaging data for liver resection. This article will give an overview of three-dimensional reconstruction technique and discuss its ability to display liver vascularity, show the relationship between tumors and liver blood vessels, and predict liver resection volume.

Randomized controlled trial analyzing the effect of 15 or 30 min intermittent Pringle maneuver on hepatocellular damage during liver surgery

BACKGROUND & AIMS

Aminotransferases are commonly used to determine the optimal duration of ischemic intervals during intermittent Pringle maneuver (IPM). However, they might not be responsive enough to detect small differences in hepatocellular damage. Liver fatty acid-binding protein (L-FABP) has been suggested as a more sensitive marker. This randomized trial aimed to compare hepatocellular injury reflected by L-FABP in patients undergoing liver resection with IPM using 15 or 30 min ischemic intervals.

METHODS

Twenty patients undergoing liver surgery were randomly assigned to IPM with 15 (15IPM) or 30 (30IPM) minutes ischemic intervals. Ten patients not requiring IPM (noIPM) served as controls. Primary endpoint was hepatocellular injury during liver surgery reflected by systemic L-FABP plasma levels. Between group comparisons were performed using area under the curve and repeated measures two-way ANOVA.

RESULTS

The IPM groups had similar characteristics. Aminotransferases did not differ significantly between 15IPM and 30IPM at any time point. L-FABP levels rose up to 1853±708 ng/ml in the 15IPM and 3662±1355 ng/ml in the 30IPM group after finishing liver transection and decreased rapidly thereafter. There were no significant differences between 15IPM and 30IPM in cumulative L-FABP level (p=0.378) or L-FABP level at any time point (p=0.149). Blood loss, remnant liver function and morbidity were comparable.

CONCLUSIONS

IPM with 15 or 30 min ischemic intervals induced similar hepatocellular injury measured by the sensitive marker L-FABP. The present study confirms the results of earlier trials, suggesting that IPM with 30 min ischemic intervals may be used.

Prediction, prevention and management of postresection liver failure

Background

Postresection liver failure (PLF) is the major cause of death following liver resection. However, there is no unified definition, the pathophysiology is understood poorly and there are few controlled trials to optimize its management. The aim of this review article is to present strategies to predict, prevent and manage PLF.

Methods

The Web of Science, MEDLINE, PubMed, Google Scholar and Cochrane Library databases were searched for studies using the terms ‘liver resection’, ‘partial hepatectomy’, ‘liver dysfunction’ and ‘liver failure’ for relevant studies from the 15 years preceding May 2011. Key papers published more than 15 years ago were included if more recent data were not available. Papers published in languages other than English were excluded.

Results

The incidence of PLF ranges from 0 to 13 per cent. The absence of a unified definition prevents direct comparison between studies. The major risk factors are the extent of resection and the presence of underlying parenchymal disease. Small-for-size syndrome, sepsis and ischaemia–reperfusion injury are key mechanisms in the pathophysiology of PLF. Jaundice is the most sensitive predictor of outcome. An evidence-based approach to the prevention and management of PLF is presented.

Conclusion

PLF is the major cause of morbidity and mortality after liver resection. There is a need for a unified definition and improved strategies to treat it.

Regional Transient Portal Ischemia and Irradiation as Preparative Regimen for Hepatocyte Transplantation

Hepatocyte transplantation is regarded as a promising option to correct hereditary metabolic liver disease. This study describes a novel method involving regional transient portal ischemia (RTPI) in combination with hepatic irradiation (IR) as a preparative regimen for hepatocyte transplantation. The right lobules of rat livers (45% of liver mass) were subjected to RTPI of 30–120 min. Liver specimens and serum samples were analyzed for transaminase levels, DNA damage, apoptosis, and proliferation. Repopulation experiments involved livers of dipeptidylpeptidase IV (DPPIV)-deficient rats preconditioned with RTPI (60–90 min) either with or without prior partial hepatic IR (25 Gy). After reperfusion intervals of 1 and 24 h, 12 million wild-type (DPPIV positive) hepatocytes were transplanted into recipient livers via the spleen. RTPI of 60–90 min caused limited hepatic injury through necrosis and induced a distinct regenerative response in the host liver. Twelve weeks following transplantation, small clusters of donor hepatocytes were detected within the portal areas. Quantitative analysis revealed limited engraftment of 0.79% to 2.95%, whereas control animals (sham OP) exhibited 4.16% (determined as relative activity of DPPIV when compared to wild-type liver). Repopulation was significantly enhanced (21.43%) when IR was performed prior to RTPI, optimum preconditioning settings being 90 min of ischemia and 1 h of reperfusion before transplantation. We demonstrate that RTPI alone is disadvantageous to donor cell engraftment, whereas the combination of IR with RTPI comprises an effective preparative regimen for liver repopulation. The method described clearly has potential for clinical application.

Factors associated with changes in coagulation profiles after living donor hepatectomy

BACKGROUND

Hepatic resection may be associated with postoperative coagulopathy. However, there is limited information about the predictors affecting coagulopathy after donor hepatectomy. We evaluated the contributors of maximal changes in prothrombin time (PT), activated thromboplastin time (aPTT), and platelet count in the development of postoperative coagulopathy.

METHODS

We retrospectively analyzed 864 living donors, all of whom received general anesthesia using desflurane, isoflurane, or sevoflurane. A coagulation derangement was defined as one or more of the following events postoperatively: peak PT >1.5 international normalized ratio (INR; highest quartile of PT), peak aPTT >46 seconds (highest quartile of aPTT), or nadir platelet count <100 × 10(9)/L. Factors were evaluated by univariate and multivariate logistic regression analysis to identify predictors of coagulopathy.

RESULTS

Mean postoperative peak PT, peak aPTT, and nadir platelet count were 1.4 ± 0.2 INR, 43.8 ± 23.7 seconds, and 155.9 ± 37.3 × 10(9)/L, respectively, with 39.4% of donors being at the risk for coagulation derangement. Multivariate logistic regression analysis revealed that predictors of such derangement included anesthesia duration, remnant liver volume, and body mass index (BMI). However, coagulation derangement was not independently associated with age, gender, volatile anesthetics, central venous pressure, fatty change in the liver, estimated blood loss, or intraoperative hypotensive episodes.

CONCLUSION

We found that long anesthesia duration, low BMI, and small remnant liver volume were predictors of coagulation derangement. These results provide a better understanding of risk factors affecting changes in coagulation profiles after living donor hepatectomy.

Scaffolds containing growth factors and extracellular matrix induce hepatocyte proliferation and cell migration in normal and regenerating rat liver

BACKGROUND & AIMS

Intrahepatic drug delivery from implantable scaffolds is being developed as a strategy to modulate growth and enhance regeneration at the time of liver resection. In this study we examine the effects of scaffolds containing hepatocyte growth factor, epidermal growth factor, fibroblast growth factor 1, fibroblast growth factor 2, and liver-derived extracellular matrix (L-ECM) when implanted into normal and partially hepatectomized rat livers.

METHODS

Scaffolds loaded with combinations of growth factors and L-ECM were implanted into normal livers (controls=L-ECM, polymer or sham) and livers following partial hepatectomy (controls=partial hepatectomy or sham). The primary end points were hepatocyte DNA synthesis and liver tissue penetration into scaffolds. Secondary end points included non-parenchymal cell DNA synthesis, liver weight analysis, liver function, and histological characterisation of the peri-implant parenchyma.

RESULTS

Four days after implantation in normal livers, there was significantly more hepatocyte proliferation around growth factor scaffolds than controls. Seven days after implantation, there was significantly more tissue penetration into growth factor scaffolds than control scaffolds. ED-1 and desmin positive cells were present in the pores of scaffolds. Two days after partial hepatectomy, there was significantly more hepatocyte proliferation around scaffold implanted livers than after partial hepatectomy alone.

CONCLUSIONS

Growth factors and L-ECM accelerated non-parenchymal cell migration into scaffolds and increased hepatocyte and non-parenchymal cell proliferation around them. These results demonstrate the potential for intrahepatic implantation of scaffolds containing growth factors and L-ECM to modulate growth in the normal and regenerating liver.

Radiofrequency ablation versus resection for liver tumours: an evidence-based approach to retrospective comparative studies

BACKGROUND

Recently randomized controlled trials have been advocated to compare radiofrequency ablation (RFA) and hepatic resection (HR) in resectable tumours and determine whether differences in observed survivals result from the heterogeneity in previous studies between RFA (treating unresectable lesions) and HR (treating lesions deemed resectable). We reviewed the literature that directly compares the treatments and employed an evidence-based approach to examine the data.

MATERIALS AND METHODS

All studies comparing RFA and HR were included. Primary outcomes were the overall survival (OS) and disease-free survival (DFS) at 3 and 5 years. A subgroup analysis was conducted for solitary or small tumors (<4 cm for colorectal metastases (CRM) or <5 cm for hepatocellular carcinoma (HCC)).

RESULTS

Most studies were retrospective. For CRM, HR was markedly superior to RFA in respect of 3- and 5-year OS as well as 5-year DFS including tumours smaller than 4 cm and solitary lesions. For HCC, HR was markedly superior to RFA for 3- and 5-year OS as well as 3-year DFS, and produced a better OS at 3 years for solitary lesions and DFS at 3 years for small tumours.

CONCLUSIONS

Multiple factors determine outcomes following treatment of liver tumours. Small or solitary lesions seem the most appropriate ones to study as this reduces the number of confounding variables, but even in these cases HR confers a better OS and DFS than RFA for both CRM and HCC. If our data are confirmed it will be important to examine other factors influencing the response.

Liver volume measurement: reason of the difference between in vivo CT-volumetry and intraoperative ex vivo determination and how to cope it

Purpose

Volumetric assessment of the liver regularly yields discrepant results between pre- and intraoperatively determined volumes. Nevertheless, the main factor responsible for this discrepancy remains still unclear. The aim of this study was to systematically determine the difference between in vivo CT-volumetry and ex vivo volumetry in a pig animal model.

Material and Methods

Eleven pigs were studied. Liver density assessment, CT-volumetry and water displacement volumetry was performed after surgical removal of the complete liver. Known possible errors of volume determination like resection or segmentation borders were eliminated in this model. Regression analysis was performed and differences between CT-volumetry and water displacement determined.

Results

Median liver density was 1.07 g/ml. Regression analysis showed a high correlation of r² = 0.985 between CT-volumetry and water displacement. CTvolumetry was found to be 13% higher than water displacement volumetry (p < 0.0001).

Conclusion

In this study the only relevant factor leading to the difference between in vivo CT-volumetry and ex vivo water displacement volumetry seems to be blood perfusion of the liver. The systematic difference of 13 percent has to be taken in account when dealing with those measures.

Compressive stenosis of the left hepatic vein as a pathogenesis of postresectional liver failure: a case report

Introduction

Postresectional liver failure (PLF) is a devastating and fatal complication of major hepatic resection, and we do not have a full understanding of the pathogenic mechanisms involved. No reliable treatment other than liver transplantation currently exists for PLF.

Case presentation

A 46-year-old Japanese man experienced PLF after an extended right hepatectomy for liver malignancy. Seven months after surgery, the patient's Model for End-Stage Liver Disease (MELD) score had reached 23. Doppler ultrasound study and three-dimensional computed tomography images showed a stenosed left hepatic vein compressed by surrounding hypertrophied hepatic parenchyma. Transluminal balloon angioplasty and stent placement therapy were conducted eight months after surgery. The pressure gradient between the hepatic vein and right atrium decreased from 13 to 3 mmHg after stent placement. Thereafter, the patient recovered.

Conclusion

Hepatic venous compression by surrounding hypertrophied hepatic parenchyma might, at least in part, be associated with the occurrence of PLF. Surgeons should bear this possibility in mind when confronted with cases of PLF, as early diagnosis and stent placement improves patients' chances of recovery.

The LiMAx test: a new liver function test for predicting postoperative outcome in liver surgery

BACKGROUND

Liver failure has remained a major cause of mortality after hepatectomy, but it is difficult to predict preoperatively. This study describes the introduction into clinical practice of the new LiMAx test and provides an algorithm for its use in the clinical management of hepatic tumours.

METHODS

Patients with hepatic tumours and indications for hepatectomy were investigated perioperatively with the LiMAx test. In one patient, analysis of liver volume was carried out with preoperative three-dimensional virtual resection.

RESULTS

A total of 329 patients with hepatic tumours were evaluated for hepatectomy. Blinded preoperative LiMAx values were significantly higher before resection (n= 139; mean 351 microg/kg/h, range 285-451 microg/kg/h) than before refusal (n= 29; mean 299 microg/kg/h, range 223-376 microg/kg/h; P= 0.009). In-hospital mortality rates were 38.1% (8/21 patients), 10.5% (2/19 patients) and 1.0% (1/99 patients) for postoperative LiMAx of <80 microg/kg/h, 80-100 microg/kg/h and >100 microg/kg/h, respectively (P < 0.0001). A decision tree was developed to avoid critical values and its prospective preoperative application revealed a reduction in mortality from 9.4% to 3.4% (P= 0.019).

DISCUSSION

The LiMAx test can validly determine liver function capacity and is feasible in every clinical situation. Combination with virtual resection could enable the calculation of residual liver function. The LiMAx decision tree algorithm for hepatectomy might significantly improve preoperative evaluation and postoperative outcome in liver surgery.

The anti-proliferative side effects of AEE788, a tyrosine kinase inhibitor blocking both EGF- and VEGF-receptor, are liver-size-dependent after partial hepatectomy in rats

BACKGROUND

Blocking of EGFR signaling by the tyrosine kinase inhibitor AEE788 was well tolerated and did not inhibit liver regeneration after standard 70% partial hepatectomy (PH) in a rat model, as demonstrated previously. However, serum levels of AEE788 at POW1 were 3-fold higher than in the non-resected control group. Therefore, we expanded theses studies to a model of extended 90%PH to investigate the role of liver size for the metabolism of AEE788 and its potential influence on side effects, liver regeneration and liver remodeling.

METHOD

Rats treated with 50 mg/kg AEE788 or solvent every other day orally were subjected to 90%PH. Animals were sacrificed at 1, 2, 7 and 28 days after PH. We measured plasma and liver levels of AEE788 and assessed anti-proliferative side effects, liver regeneration, and liver architecture.

RESULT

Liver regeneration and liver architecture were not impaired by AEE788 treatment after 90%PH. 90%PH caused a clinically relevant drug accumulation within 1 week of treatment (AEE788 serum and tissue levels: 90%PH*>70%PH*>normal control, *p < 0.05), suggesting a liver-size-dependent metabolism of the drug. Drug accumulation after 90%PH was associated with severe side effects (delayed body weight recovery, diarrhea, impaired hair growth) within 1 week of treatment.

CONCLUSION

Treatment with AEE788 could be a potential strategy for adjuvant treatment after oncological liver resection, as liver regeneration was not impaired. Our results suggest a liver-size-dependent metabolism of AEE788 leading to drug accumulation and subsequently to severe side effects. It calls for therapeutic drug monitoring in the early postoperative phase after extended resection.

Effect of leflunomide on liver regeneration after partial hepatectomy in rats

PURPOSE

Partial hepatectomy (PH) can be an inevitable surgical therapy in some conditions, such as hepatic malignancies, trauma or partial liver transplantation. Its capacity for regeneration distinguishes the liver from other essential organs. Regeneration is a complex process involving growth factors, cytokines, transcription factors, hormones, and oxidative stress products. In the event of ineffective or total absent liver regeneration, the life threatening picture of acute liver failure may supervene. In the present research, we studied the effect of leflunomide, a novel immunosuppressive and antiinflammatory agent against autoimmune disease, on hepatic regeneration after PH in Wistar Albino rats.

METHODS

Thirty-five Wistar albino rats were divided into five groups: group 1, control; group 2, sham; group 3, drug control (was treated with leflunomide 10 mg/kg/d/i.g.); group 4, PH; group 5, PH + leflunomide. As for PH, approximately 70% of the rat liver was surgically removed under general anesthesia. On postoperative day 3, all rats were humanely killed. Catalase (CAT), superooxide dismutase (SOD) and myeloperoxidase (MPO) activities with malondialdehyde (MDA), nitric oxide and protein carbonyl (PC) levels were determined in remnant liver tissue. Inflammatory process and liver regeneration were evaluated with H&E and KI67, respectively.

RESULTS

The tissue levels of MDA, PC and MPO were lower in group 5 than levels in group 1. PH significantly decreased the enzymatic activity of CAT (p < 0.05) and SOD. This reduction was significantly improved by the treatment with leflunomide. Histopathologically the enhancement of the liver parenchymal regeneration in the group 5 was significantly greater than the group 4.

CONCLUSION

The findings imply that oxidative stress products play a preventive role in liver regeneration after PH and leflunomide ameliorates the regeneration probably by the radical scavenging and antioxidant activities.

Predicting liver failure following major hepatectomy

Pre-operative determination of the risk of liver dysfunction has come under criticism with regards to its usefulness in clinical practice. Opinion is split between centres which use such tests uniformly on all patients and those where clinical judgment alone is used. Published data would not suggest any difference in mortality, morbidity or liver failure rates between these groups. This review outlines and presents the evidence for pre-operative quantification of functional liver remnant volume.

The costs of postoperative liver failure and the economic impact of liver function capacity after extended liver resection--a single-center experience

PURPOSE

Postoperative liver failure (PLF) is a relatively frequent and life-threatening complication after extended liver resection. This study describes the economic burden of PLF from the hospitals' perspective and explores the role of liver function capacity.

MATERIALS AND METHODS

Economic data of total costs and cost distribution were analyzed for 48 patients who had participated in a prospective study with the LiMAx test, a novel test for liver function capacity. For this population, detailed individual data were available. The economic data were analyzed and adjusted for relevant covariates. In addition, economic data of 916 patients who had undergone liver resection during 2005-2007 were retrieved from the hospitals' medical controlling office for comparison.

RESULTS

A significant difference between the costs of patients with regular recovery (25,980 Euro [95% confidence interval (95%CI) = 9,559 to 42,401]) versus patients developing PLF (82,199 Euro [95%CI = 42,812 to 121,586]; p = 0.013) was observed. The mean additional costs of PLF were 56,219 Euro. An equivalent cost difference of mortality was obtained from the analysis of 916 patients. Patients developing PLF had a decreased LiMAx of 61 microg/kg/h compared to the regular group 122 microg/kg/h (p < 0.001) after surgery. Initial postoperative LiMAx and total costs revealed a linear correlation coefficient of r = -0.340 (p = 0.018).

CONCLUSIONS

PLF is a very relevant medical and economic problem. Liver function capacity does not only predict PLF but also correlates with total costs in general.

Palliative cytoreductive surgery versus other palliative treatments in patients with unresectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours are tumours of cells which possess secretory granules and originate from the neuroectoderm. While liver resection is generally advocated in patients with resectable liver alone metastases, the management of patients with liver metastases, which cannot be completely resected, is controversial.

OBJECTIVES

To determine if cytoreductive surgery is better than other palliative treatments in patients with liver metastases from gastro-entero-pancreatic neuroendocrine tumours, which cannot be completely resected.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and LILACS until July 2008 for identifying the randomised trials.

SELECTION CRITERIA

Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other palliative treatments (chemotherapy or hormone-therapy or immunotherapy) or no treatment in patients with liver metastases from neuroendocrine tumours, which cannot be completely resected, were considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

The literature provides no evidence from randomised clinical trials in order to assess the role of cytoreductive surgery in non-resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours. High-quality randomised clinical trials may become feasible to perform if their conduct and study design is thoroughly considered in all their practical and methodological aspects. Pilot randomised clinical trials, which can guide the study design of definitive randomised clinical trials, are necessary.

Vascular occlusion for elective liver resections

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection. There is considerable controversy regarding whether vascular occlusion should be used or not during elective liver resections.

OBJECTIVES

To assess the advantages (decreased blood loss and peri-operative morbidity) and disadvantages (ischaemia-reperfusion injury related complications like liver dysfunction) of vascular occlusion during elective liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008.

SELECTION CRITERIA

We included randomised clinical trials comparing vascular occlusion versus no vascular occlusion during elective liver resections (irrespective of language or publication status).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. We calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat or available case analysis.

MAIN RESULTS

We identified a total of five trials (of high bias-risk) which compared vascular occlusion (n = 166) versus no vascular occlusion (n = 165). Three of the five trials comparing vascular occlusion and no vascular occlusion used intermittent vascular occlusion. There was no difference in mortality, liver failure, or other morbidities. The blood loss was significantly lower in vascular occlusion compared with no vascular occlusion. The liver enzymes were significantly elevated in the vascular occlusion group compared with no vascular occlusion.

AUTHORS' CONCLUSIONS

Intermittent vascular occlusion seems safe in liver resection. However, it does not seem to decrease morbidity. More randomised trials seem to be needed.

Ischaemic pre-conditioning for elective liver resections performed under vascular occlusion

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection surgery. The enzyme markers of liver injury are elevated if vascular occlusion is employed during liver resection. It is not clear whether ischaemic preconditioning prior to vascular occlusion has a protective effect during elective liver resections.

OBJECTIVES

To assess the advantages (decreased ischaemia-reperfusion injury) and any potential disadvantages of ischaemic preconditioning prior to vascular occlusion during liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008.

SELECTION CRITERIA

We included randomised clinical trials comparing ischaemic preconditioning versus no ischaemic preconditioning prior to vascular occlusion (irrespective of the method of vascular occlusion) during elective liver resections (irrespective of language or publication status).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. We calculated the risk ratio, mean difference, or standardised mean difference with 95% confidence intervals based on intention-to-treat or available data analysis.

MAIN RESULTS

We included four trials with 271 patients undergoing open liver resections. The patients were randomised to ischaemic preconditioning (n = 135) and no ischaemic preconditioning (n = 136) prior to continuous vascular occlusion (portal triad clamping in three trials and hepatic vascular exclusion in one trial). All the trials excluded cirrhotic patients. We assessed all the four trials as having high risk of bias. There was no difference in mortality, liver failure, other peri-operative morbidity, hospital stay, intensive therapy unit stay, and operating time between the two groups. The proportion of patients requiring blood transfusion was lower in the ischaemic preconditioning group. There was also a trend towards a lower amount of red cell transfusion favouring ischaemic preconditioning group. There was no difference in the haemodynamic changes, blood loss, bilirubin, or prothrombin activity between the two groups. The enzyme markers of liver injury were lower in the ischaemic preconditioning group on the first post-operative day.

AUTHORS' CONCLUSIONS

Currently, there is no evidence to suggest a protective effect of ischaemic preconditioning in non-cirrhotic patients undergoing liver resection under continuous vascular occlusion. Ischaemic preconditioning reduces the blood transfusion requirements in patients undergoing liver resection.

Liver failure after major hepatic resection

INTRODUCTION

The consequence of excessive liver resection is the inexorable development of progressive liver failure characterised by the typical stigmata associated with this condition, including worsening coagulopathy, hyperbilirubinaemia and encephalopathy. The focus of this review will be to investigate factors contributing to hepatocyte loss and impaired regeneration.

METHODS

A literature search was undertaken of Pubmed and related search engines, examining for articles relating to hepatic failure following major hepatectomy.

RESULTS

In spite of improvements in adjuvant chemotherapy and increasing surgical confidence and expertise, the parameters determining how much liver can be resected have remained largely unchanged. A number of preoperative, intraoperative and post-operative factors all contribute to the likelihood of liver failure after surgery.

CONCLUSIONS

Given the magnitude of the surgery, mortality and morbidity rates are extremely good. Careful patient selection and preservation of an obligate volume of remnant liver is essential. Modifiable causes of hepatic failure include avoidance of sepsis, drainage of cholestasis with restoration of enteric bile salts and judicious use of portal triad inflow occlusion intra-operatively. Avoidance of post-operative sepsis is most likely to be achieved by patient selection, meticulous intra-operative technique and post-operative care. Modulation of portal vein pressures post-operatively may further help reduce the risk of liver failure.