Circulating Cytokines, Chemokines, and Stress Hormones are Increased in Patients with Organ Dysfunction Following Liver Resection

Indications of pro-inflammatory cytokines in laparoscopic and open liver resection for early-stage hepatocellular carcinoma

BACKGROUND

Our clinical practice of laparoscopic liver resection (LLR) had achieved better short-term and long-term benefits for patients with hepatocellular carcinoma (HCC) over open liver resection (OLR), but the underlying mechanisms are not clear. This study was to find out whether systemic inflammation plays an important role.

METHODS

A total of 103 patients with early-stage HCC under liver resection were enrolled (LLR group, n = 53; OLR group, n = 50). The expression of 9 inflammatory cytokines in patients at preoperation, postoperative day 1 (POD1) and POD7 was quantified by Luminex Multiplex assay. The relationships of the cytokines and the postoperative outcomes were compared between LLR and OLR.

RESULTS

Seven of the circulating cytokines were found to be significantly upregulated on POD1 after LLR or OLR compared to their preoperative levels. Compared to OLR, the POD1 levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein-1 (MCP-1) in the LLR group were significantly lower. Higher POD1 levels of these cytokines were significantly correlated with longer operative time and higher volume of blood loss during operation. The levels of these cytokines were positively associated with postoperative liver injury, and the length of hospital stay. Importantly, a high level of IL-6 at POD1 was a risk factor for HCC recurrence and poor disease-free survival after liver resection.

CONCLUSIONS

Significantly lower level of GM-CSF, IL-6, IL-8, and MCP-1 after liver resection represented a milder systemic inflammation which might be an important mechanism to offer better short-term and long-term outcomes in LLR over OLR.

Lipid droplet deposition in the regenerating liver: A promoter, inhibitor, or bystander?

Liver regeneration (LR) is a complex process involving intricate networks of cellular connections, cytokines, and growth factors. During the early stages of LR, hepatocytes accumulate lipids, primarily triacylglycerol, and cholesterol esters, in the lipid droplets. Although it is widely accepted that this phenomenon contributes to LR, the impact of lipid droplet deposition on LR remains a matter of debate. Some studies have suggested that lipid droplet deposition has no effect or may even be detrimental to LR. This review article focuses on transient regeneration-associated steatosis and its relationship with the liver regenerative response.

Post-hepatectomy liver failure prediction and prevention: Development of a nomogram containing postoperative anticoagulants as a risk factor

INTRODUCTION AND OBJECTIVES

Posthepatectomy liver failure (PHLF) is a serious complication after hepatectomy, and its effective methods for preoperative prediction are lacking. Here, we aim to identify predictive factors and build a nomogram to evaluate patients' risk of developing PHLF.

PATIENTS AND METHODS

A retrospective review of a training cohort, including 199 patients who underwent hepatectomy at the Shanghai Eastern Hepatobiliary Surgery Hospital, was conducted. Independent risk variables for PHLF were identified using multivariate analysis of perioperative variables, and a nomogram was used to build a predictive model. To test the predictive power, a prospective study in which a validation cohort of 71 patients was evaluated using the nomogram. The prognostic value of this nomogram was evaluated by the C-index.

RESULTS

Independent risk variables for PHLF were identified from perioperative variables. In multivariate analysis of the training cohort, tumor number, Pringle maneuver, blood loss, preoperative platelet count, postoperative ascites and use of anticoagulant medications were determined to be key risk factors for the development of PHLF, and they were selected for inclusion in our nomogram. The nomogram showed a 0.911 C-index for the training cohort. In the validation cohort, the nomogram also showed good prognostic value for predicting PHLF. The validation cohort was used with similarly successful results to evaluate risk in two previously published study models with calculated C-indexes of 0.718 and 0.711.

CONCLUSION

Our study establishes for the first time a novel nomogram that can be used to identify patients at risk of developing PHLF.

Perioperative steroid administration reduces overall complications in patients undergoing liver resection: A meta-analysis

BACKGROUND

Hepatic resection (HR) results in an inflammatory response that can be modified by perioperative steroid administration. However, it remains to be determined if this response's attenuation translates to a reduction in complications.

AIM

To evaluate if perioperative administration of steroids reduces complications following HR.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted on PubMed, Embase, and Cochrane Central Register of Controlled Trials to evaluate the effect of perioperative steroid (compared to placebo or no intervention) use in patients undergoing HR. Clinical outcomes were extracted, and meta-analysis was performed.

RESULTS

8 RCTs including 590 patients were included. Perioperative steroid administration was associated with significant reduction in postoperative complications [odds ratios: 0.58; 95% confidence intervals (CI): 0.35-0.97, P = 0.04]. There was also improvement in biochemical and inflammatory markers, including serum bilirubin on postoperative day 1 [MD: -0.27; 95%CI: (-0.47, -0.06), P = 0.01], C-reactive protein on postoperative day 3 [MD: -4.89; 95%CI: (-5.83, -3.95), P < 0.001], and interleukin-6 on postoperative day 1 [MD: -54.84; 95%CI: (-63.91, -45.76), P < 0.001].

CONCLUSION

Perioperative steroids administration in HR may reduce overall complications, postoperative bilirubin, and inflammation. Further studies are needed to determine the optimal dose and duration and patient selection.

Influence of cytokines, circulating markers and growth factors on liver regeneration and post-hepatectomy liver failure: a systematic review and meta-analysis

The pathophysiology of post-hepatectomy liver failure is not entirely understood but is rooted in the disruption of normal hepatocyte regeneration and homeostasis. Current investigations of post-hepatectomy liver failure and regeneration are focused on evaluation of circulating hepatic function parameters (transaminases, cholestasis, and coagulation parameters), volumetry and hepatic hemodynamics. However, identification of biochemical factors associated with regeneration and post hepatectomy liver failure is crucial for understanding the pathophysiology and identification of patients at risk. The objective of the present systematic review was to identify circulating factors associated with liver regeneration and post hepatectomy liver failure in patients undergoing hepatectomy. The quantitative analysis was intended if studies provided sufficient data. Electronic databases (MEDLINE via PubMed, Web of Knowledge, Cochrane Library and WHO International Clinical Trials Registry Platform) were searched for publications on cell signaling factors in liver regeneration and post-hepatectomy liver failure following liver resection in clinical setting. No date restriction was given. No language restriction was used. Studies were assessed using MINORS. This study was registered at PROSPERO (CRD42020165384) prior to data extraction. In total 1953 publications were evaluated for titles and abstracts after exclusion of duplicates. Full texts of 167 studies were further evaluated for inclusion. 26 articles were included in the review and 6 publications were included in the meta-analyses. High levels of serum hyaluronic acid even preoperatively are associated with PHLF but especially increased levels early after resection are predictive of PHLF with high sensitivity and specificity. Postoperative elevation of HA to levels between 100 and 500 ng/ml is increased the risk for PHLF ([OR] = 246.28, 95% [CI]: 11.82 to 5131.83; p = 0.0004) Inteleukin-6 levels show contradicting result in association with organ dysfunction. HGF positively correlates with liver regeneration. Overall, due to heterogeneity, scarcity, observational study design and largely retrospective analysis, the certainty of evidence, assessed with GRADE, is very low. High levels of serum hyaluronic acid show a strong association with PHLF and increased levels after resection are predictive of PHLF with high sensitivity and specificity, even on POD1. Interleukin-6 levels need to be studied further due to contradictive results in association with organ dysfunction. For HGF, no quantitative analysis could be made. Yet, most studies find positive correlation between high HGF levels and regeneration. Prospective studies investigating HGF and other growth factors, hyaluronic acid and interleukins 1 and 6 in correlation with liver regeneration measured sequentially through e.g. volumetry, and liver function parameters, preferably expanding the analysis to include dynamic liver function tests, are needed to sufficiently illustrate the connection between biomolecule levels and clinical outcomes.

The potential of adipokines in identifying multiple trauma patients at risk of developing multiple organ dysfunction syndrome

Background

Multiple organ dysfunction syndrome (MODS) and the consecutive multiple organ failure (MOF) are severe and dreaded complications with a high mortality in multiple trauma patients. The aim of this study was to investigate the potential of the adipokines leptin, resistin, interleukin-17A and interleukin-33 as possible biomarkers in the early posttraumatic inflammatory response and for identifying severely traumatized patients at risk of developing MODS.

Methods

In total, 14 multiple trauma patients with an injury severity score (ISS) ≥ 16 as well as a control group of 14 non-multiple trauma patients were included in this study and blood samples were taken at the time points 0, 6, 24, 48 and 72 h after admission. For the trauma patients, the SIRS and Denver MOF score were determined daily. The quantitative measurement of the plasma concentrations of the adipokines was performed using ELISA.

Results

In the statistical analysis, the multiple trauma patients showed statistically significant higher plasma concentrations of leptin, resistin, IL-17A and IL-33 compared to the control group. In addition, there was a statistically significant positive correlation between the concentrations of resistin, IL-17A and IL-33 and the corresponding SIRS scores and between the concentrations of resistin, IL-17A and IL-33 and the corresponding Denver MOF scores. Finally, ROC curve analysis revealed that the adipokines leptin and IL-17A are suitable diagnostic markers for the discrimination between multiple trauma patients with and without MOF.

Conclusions

Leptin and IL-17A could be suitable diagnostic markers to identify severely injured patients with a developing SIRS and MOF earlier, to adjust surgical therapy planning and intensive care.

Predictive Ability of Preoperative PT-INR and Postoperative MCP1 for Post-hepatectomy Liver Failure

BACKGROUND

We sought a diagnostic tool using perioperative variables that might predict post-hepatectomy liver failure (PHLF).

PATIENTS AND METHODS

In 68 patients undergoing major hepatectomy, data on inflammatory markers and coagulation factors were prospectively collected and were compared between patients with International Study Group of Liver Surgery definition grade B/C PHLF (LF group) and those without LF (non-LF group).

RESULTS

Preoperatively, the LF group (n=9; 13.2%) had a lower platelet count and a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13 (ADAMTS13) activity and a higher prothrombin time-International Normalized Ratio (PT-INR) than the non-LF group. On postoperative day 1, the LF group had significantly higher serum interleukin 6 (IL6), C-C motif chemokine ligand 2 (CCL2), and IL10 levels than the non-LF group. The logistic regression model that included preoperative PT-INR and CCL2 on postoperative day 1 predicted grade B/C PHLF with 100% sensitivity and 89.8% specificity.

CONCLUSION

Our findings suggest that the combination of preoperative PT-INR and CCL2 on postoperative day 1 can predict PHLF earlier and precisely after major hepatectomy.

The association between the inflammatory response to surgery and postoperative complications in older patients with cancer; a prospective prognostic factor study

BACKGROUND

Accurate prognostic biomarkers would substantially improve surgical planning and decisions making yet no studies have been reported exploring the inflammatory response in surgically treated older patients with cancer. The aim of this study was to explore inflammatory biomarkers as potential prognostic factors for postoperative complications within 30 days in older patients with cancer.

METHOD

Patients 65 years and older undergoing surgery for removal of a solid malignant tumour were included in an observational cohort study. All complications occurring up to 30 days postoperatively were documented prospectively. Inflammatory markers were measured in plasma samples pre- and postoperatively: C-reactive protein (CRP), Interleukin-1 beta (IL-1β), IL-6, IL-10, IL-12, and Tumour necrosis factor-alpha (TNF-α). Associations between inflammatory markers and postoperative complications were explored using logistic regression analysis.

RESULTS

Between July 2010 and April 2014, plasma samples of 224 patients were collected. Median age was 72 (65-89) years and 116 (51.8%) patients were female. Approximately half of the patients developed postoperative complications (49.6%) of whom 62 patients (55.9%) developed >1 complication. An independent prognostic effect was observed for the inflammatory biomarkers IL-6 and IL-10 for the occurrence of postoperative complications.

CONCLUSION

The perioperative inflammatory response is associated with complications, independently from patient and surgical factors which are also associated with outcome. Research is warranted towards further exploration of the perioperative inflammatory response with the aim to improve perioperative care and outcome, and might help to improve surgical planning and decision making for older patients with cancer.

Glucocorticoid use and ischemia-reperfusion injury in laparoscopic liver resection: Randomized controlled trial

AIM

Laparoscopic liver resection (LLR) is increasingly carried out worldwide. However, there are concerns regarding ischemia-reperfusion injury caused by pneumoperitoneum and the Pringle maneuver. It is not clear whether perioperative use of glucocorticoids lowers the risk of ischemia-reperfusion hepatic injury in LLR as has been reported for open liver resection. The aim of the present study was to investigate the role of perioperative glucocorticoid use in improving hepatic function and surgical outcomes after LLR.

METHODS

In this double-blind, randomized controlled trial (UMIN000013823), we enrolled 130 patients who presented to our institution for LLR between April 2014 and October 2018. Six patients were excluded, resulting in 124 patients being randomized to either the glucocorticoid or the control group. Preoperatively, patients in the glucocorticoid group received 500 mg methylprednisolone in saline solution, patients in the control group saline solution only. Surgical outcomes and blood parameters were compared between the two groups.

RESULTS

The Pringle maneuver could not be carried out in 24 patients, resulting in 50 patients in each group being included in the analysis. Postoperatively, total, direct and indirect bilirubin, and C-reactive protein and interleukin-6 levels were significantly lower, albumin levels were significantly higher, and prothrombin time was significantly shorter in the glucocorticoid than in the control group. Surgical outcomes were not significantly different between the groups.

CONCLUSION

This first report on preoperative glucocorticoid use in LLR showed that it significantly improved postoperative liver function and thus might enhance the safety of LLR.

Systematic Review and Meta-Analysis of the Benefit and Safety of Preoperative Administration of Steroid in Patients Undergoing Liver Resection

Objective: To evaluate the benefit and safety of preoperative administration of steroid in patients undergoing liver resection.

Methods: Randomized controlled trials (RCTs) which comparing preoperative administration of steroid in patients undergoing liver resection with control group were identified through a systematic literature search in PubMed, Embase, and Cochrane Library Central databases. This meta-analysis was carried out to assess the liver function, inflammatory response, and postoperative complications after liver surgery.

Results: Six RCTs including 411 patients were reviewed. The pooled result showed that there was no significant difference in the incidence of overall complications between the steroid group and the control group (OR, 0.57; 95% CI, 0.27–1.17; P = 0.13). With respect to specific complications, no significant difference was detected between the two groups in infection complications (OR, 0.95; 95% CI, 0.13–6.95; P = 0.96), wound complications (OR, 0.65; 95% CI, 0.32–1.33; P = 0.24), liver failure (OR, 0.41; 95% CI, 0.10–1.64; P = 0.21), bile leakage (OR, 0.57; 95% CI, 0.17–1.89; P = 0.36), and pleural effusion (OR, 1.24; 95% CI, 0.55–2.78; P = 0.60). For liver function, the level of serum total bilirubin (TB) on postoperative day 1 (POD 1) was significantly decreased associated with the intervention of steroid (MD, −0.54; 95% CI, −0.94 to −0.15; P = 0.007). However, no significant difference was found in the level of alanine aminotransferase (ALT) (MD, −69.39; 95% CI, −226.52 to 87.75; P = 0.39) and aspartate aminotransferase (AST) (MD, −93.44; 95% CI, −275.68 to 88.80; P = 0.31) on POD 1 between the two groups. Serum IL-6 level on POD 1 (MD, −57.98; 95% CI, −73.04 to −42.91; P < 0.00001) and CRP level on POD 3 (MD, −4.83; 95% CI, −6.07 to −3.59; P < 0.00001) were significantly reduced in the steroid group comparing to the control group. Compared with the control group, the level of early postoperative IL-10 was significant higher in the steroid group (MD, 17.89; 95% CI, 3.89 to 31.89; P = 0.01).

Conclusion: Preoperative administration of steroid in liver resection can promote the recovery of liver function and inhibit the inflammatory response without increasing postoperative complications. Further studies should focus on determining which patients would benefit most from the steroid.

The inflammatory response to stress and angiogenesis in liver resection for colorectal liver metastases: a randomized controlled trial comparing open versus laparoscopic approach

BACKGROUND

This study evaluates the surgical stress response following laparoscopic and open liver resection for colorectal liver metastasis (CRLM).

METHODS

Patients with CRLM were prospectively randomized to receive open or laparoscopic liver resection (NCT03131778). Blood samples were drawn preoperatively and 24 h after resection. The serum interleukin-6 (IL-6) and IL-8 levels were measured. Furthermore, the mRNA levels of angiogenesis-related factors (vascular endothelial growth factor [VEGF] and HIF-1) and inflammation-related factors (COX-2 and MMP-9) in both tumor tissue and normal liver parenchyma were detected.

RESULTS

Twenty patients for each arm were included. Size of metastasis, type of resection, and neoadjuvant therapy were comparable between groups. Postoperative stay was shorter in the laparoscopic group. Higher levels of IL-6 were observed after the operation in both open and laparoscopic groups, although no differences in the post-operative levels between the groups was noted. Similarly, there were no significant differences in the mRNA expression of VEGF, HIF-1, MMP-9, and COX-2 between the treatment groups. No differences were observed in terms of overall survival and disease free survival.

CONCLUSIONS

The immunological effects of treatment were similar between the groups. Thus, the laparoscopic approach does not seem to significantly influence the surgical stress and tumor related factors in patients suffering from colorectal liver metastases.

Inflammation and pro-resolution inflammation after hepatobiliary surgery

Background

The magnitude of the perioperative inflammatory response plays a role in surgical outcomes. However, few studies have explored the mechanisms of the resolution of inflammation in the context of surgery. Here, we described the temporal kinetics of interleukin-6, cortisol, lipoxin A4, and resolvin D in patients who underwent oncologic liver resections.

Methods

All patients gave written informed consent. Demographic and perioperative surgical data were collected, along with blood samples, before surgery and on the mornings of postoperative days 1, 3, and 5. Interleukin-6, cortisol, lipoxin-A4, and resolvin D were measured in plasma. A P value < 0.05 was considered statistically significant.

Results

Forty-one patients were included in the study. Liver resection for colorectal metastatic disease was the most commonly performed surgery. The plasma concentrations of interleukin-6 were highest on day 1 after surgery and remained higher than the baseline up to postoperative day 1. Postoperative complications occurred in 14 (24%) patients. Cortisol concentrations spiked on postoperative day 1. The concentrations of lipoxin A4 and resolvin D were lowest on day 1 after surgery.

Conclusions

The inflammatory response associated with hepatobiliary surgery is associated with low circulating concentrations of lipoxin A4 and resolvin D that mirror, in an opposite manner, the kinetics of interleukin 6 and cortisol.

Trial registration

NCT01438476

Liver resection for cancer: New developments in prediction, prevention and management of postresectional liver failure

Hepatic failure is a feared complication that accounts for up to 75% of mortality after extensive liver resection. Despite improved perioperative care, the increasing complexity and extensiveness of surgical interventions, in combination with an expanding number of resections in patients with compromised liver function, still results in an incidence of postresectional liver failure (PLF) of 1-9%. Preventive measures aim to enhance future remnant liver size and function. Numerous non-invasive techniques to assess liver function and predict remnant liver volume are being developed, along with introduction of novel surgical strategies that augment growth of the future remnant liver. Detection of PLF is often too late and treatment is primarily symptomatic. Current therapeutic research focuses on ([bio]artificial) liver function support and regenerative medicine. In this review we discuss the current state and new developments in prediction, prevention and management of PLF, in light of novel insights into the aetiology of this complex syndrome.

LAY SUMMARY

Liver failure is the main cause of death after partial liver resection for cancer, and is presumably caused by an insufficient quantity and function of the liver remnant. Detection of liver failure is often too late, and current treatment focuses on relieve of symptoms. New research initiatives explore artificial support of liver function and stimulation of regrowth of the remnant liver.

Nutrition and Immune-Modulatory Intervention in Surgical Patients With Gastric Cancer

This study evaluated the effect of an immune-modulatory diet on patients with gastric cancer and identified the parameters associated with postoperative outcomes. This was a single-arm prospective intervention study. At baseline, patients were assessed for nutrition (Patient-Generated Subjective Global Assessment), inflammatory markers (albumin, C-reactive protein, and interleukin 6 [IL-6]), and immune markers (percentage NK, CD4, CD8, and CD4:CD8 ratio); they also received nutrition counseling and high-calorie/protein supplement. A week before surgery, they were assessed for nutrition and inflammatory/immune markers and started on an immune-modulatory supplement until the day before surgery, when they were evaluated again. On the second postoperative day, patients were assessed for inflammatory/immune parameters, and a final nutrition evaluation was performed until the day of discharge. Complications were recorded daily and up to 30 days after discharge. Thirty-seven patients (60 ± 10 years old) were included, and 57% were classified as malnourished. Maintenance of nutrition and immune parameters occurred throughout the study period, but we found a preoperative increase in C-reactive protein (0.1-1.5 mg/dL) and IL-6 (2.0-14.2 pg/mL) and a postoperative increase in the CD4:CD8 ratio (2.3 ± 1.0). Complications and death were seen in 35%, especially patients with higher preoperative IL-6 (2.2-46 pg/mL), lower CD4:CD8 ratio (1.7 ± 0.5), and lower protein (1.2 ± 0.5 g/kg/d) and calorie intake (1552 ± 584 kcal/kg/d). The high-calorie/protein supplementation with the immune-modulating diet was able to maintain the nutrition and immune status of patients with gastric cancer.

Cytokine expression in the visceral adipose tissue after laparoscopic and conventional surgery in a rodent model

Background

Laparoscopic Surgery has become a worldwide standard procedure for a variety of indications. This has been attributed to a milder postoperative inflammatory response by the innate immune system potentially mediated through immune mediators released by the visceral adipose tissue (VAT). However, an in vivo experimental evidence is lacking and is the issue of our present study.

Methods

Male Wistar rats (N = 24) underwent standardized surgical procedures of conventional cecum resection (CCR), conventional sham operation, laparoscopic cecum resection (LCR), or laparoscopic sham operation. Cytokine expression of leptin, resistin, and IL-6 was analyzed in VAT before and after resection by quantitative RT-PCR.

Results

Postoperative leptin gene expression was reduced in the CCR and LCR groups, while expression was not significantly affected in both sham groups compared to the preoperative levels. In contrast, IL-6 expression was not affected in the LCR group, but was significantly elevated in the CCR cohort. The IL-6 expression was significantly higher in CCR compared to LCR. Resistin expression levels did not differ between all groups.

Conclusions

Our study underlines the role of immunological involvement of VAT in the postoperative phase. Low leptin levels seem to act as a stimulator for energy uptake in order to cope with postoperative stress. A lower IL-6 expression in the LCR compared to the CCR group may indicate a weaker inflammatory activity potentially adding to the clinical benefits observed in patients undergoing LS.

Transection Speed and Impact on Perioperative Inflammatory Response - A Randomized Controlled Trial Comparing Stapler Hepatectomy and CUSA Resection

Background

Parenchymal transection represents a crucial step during liver surgery and many different techniques have been described so far. Stapler resection is supposed to be faster than CUSA resection. However, whether speed impacts on the inflammatory response in patients undergoing liver resection (LR) remains unclear.

Materials and Methods

This is a randomized controlled trial including 40 patients undergoing anatomical LR. Primary endpoint was transection speed (cm²/min). Secondary endpoints included the perioperative change of pro- and anti-inflammatory cytokines, overall surgery duration, length of hospital stay, morbidity and mortality.

Results

Mean transection speed was significantly higher in patients undergoing stapler hepatectomy compared to CUSA resection (CUSA: 1 (0.4) cm²/min vs. Stapler: 10.8 (6.1) cm²/min; p<0.0001). Analyzing the impact of surgery duration on inflammatory response revealed a significant correlation between IL-6 levels measured at the end of surgery and the overall length of surgery (p<0.0001, r = 0.6188). Patients undergoing CUSA LR had significantly higher increase of interleukin-6 (IL-6) after parenchymal transection compared to patients with stapler hepatectomy in the portal and hepatic veins, respectively (p = 0.028; p = 0.044). C-reactive protein levels on the first post-operative day were significantly lower in the stapler cohort (p = 0.010). There was a trend towards a reduced overall surgery time in patients with stapler LR, especially in the subgroup of patients undergoing minor hepatectomies (p = 0.020).

Conclusions

Liver resection using staplers is fast, safe and suggests a diminished inflammatory response probably due to a decreased parenchymal transection time.

Trial Registration

ClinicalTrials.gov NCT01785212

Systematic review of pathophysiological changes following hepatic resection

OBJECTIVES

Major hepatic resection is now performed frequently and with relative safety, but is accompanied by significant pathophysiological changes. The aim of this review is to describe these changes along with interventions that may help reduce the risk for adverse outcomes after major hepatic resection.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched for relevant literature published from January 2000 to December 2011. Broad subject headings were 'hepatectomy/', 'liver function/', 'liver failure/' and 'physiology/'.

RESULTS

Predictable changes in blood biochemistry and coagulation occur following major hepatic resection and alterations from the expected path indicate a complicated course. Susceptibility to sepsis, functional renal impairment, and altered energy metabolism are important sequelae of post-resection liver failure.

CONCLUSIONS

The pathophysiology of post-resection liver failure is difficult to reverse and thus strategies aimed at prevention are key to reducing morbidity and mortality after liver surgery.

Evidence for instant blood-mediated inflammatory reaction in clinical autologous islet transplantation

A nonspecific inflammatory and thrombotic reaction termed instant blood-mediated inflammatory reaction (IBMIR) has been reported when allogenic or xenogenic islets come into contact with blood. This reaction is known to cause significant loss of transplanted islets. We hypothesized that IBMIR occurs in patients undergoing total pancreatectomy followed by autologous islet transplantation (TP-AIT) and tested this hypothesis in 24 patients and in an in vitro model. Blood samples drawn during the peritransplant period showed a significant and rapid increase of thrombin-anti-thrombin III complex (TAT) and C-peptide during islet infusion, which persisted for up to 3 h, along with a decreased platelet count. A concomitant increase in levels of inflammatory proteins IL-6, IL-8 and interferon-inducible protein-10 was observed. An in vitro model composed of pure islets plus autologous blood also demonstrated significantly increased levels of TAT (p<0.05), C-peptide (p<0.05), tumor necrosis factor-alpha (p<0.05) and MCP-1 (p<0.05), as well as strong tissue factor expression in islets. Islet viability decreased significantly but was rescued by the presence of low-molecular-weight dextran sulfate. In conclusion, AIT-induced elevation of TAT and destruction of islets suggests that IBMIR might occur during AIT. Modulating this process may help improve islet engraftment and the insulin independence rate in TP-AIT patients.

Systematic review and meta-analysis of the effect of perioperative steroids on ischaemia-reperfusion injury and surgical stress response in patients undergoing liver resection

BACKGROUND

Several therapeutic strategies, such as ischaemic preconditioning, intermittent or selective pedicle clamping and pharmacological interventions, have been explored to reduce morbidity caused by hepatic ischaemia-reperfusion injury and the surgical stress response. The role of steroids in this setting remains controversial.

METHODS

A comprehensive literature search in MEDLINE, Embase and the Cochrane Register of Clinical Trials (CENTRAL) was conducted (1966 onwards), identifying studies comparing perioperative administration of intravenous steroids with standard care or placebo, in the setting of liver surgery. Randomized Controlled trials (RCTs) and non-RCTs were included. Critical appraisal and meta-analysis were carried out according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) statement.

RESULTS

Six articles were included; five were RCTs. Pooling the results revealed that patients receiving intravenous glucocorticoids were 24 per cent less likely to suffer postoperative morbidity compared with controls (risk ratio 0.76, 95 per cent confidence interval 0.57 to 0.99; P = 0.047). The treated group experienced a significantly greater rise in early postoperative interleukin (IL) 10 levels compared with controls. In addition, steroids significantly reduced postoperative blood levels of bilirubin, and of inflammatory markers such as IL-6 and C-reactive protein. There was no evidence supporting a risk difference in infectious complications and wound healing between study groups.

CONCLUSION

Perioperative steroids have a favourable impact on postoperative outcomes after liver resection.

Cell death biomarkers as early predictors for hepatic dysfunction in patients after orthotopic liver transplantation

BACKGROUND

Valid prognostic factors for early identification of a complicated course after orthotopic liver transplantation from deceased donors are rare. The aim of this study was to investigate the prognostic value of different cell death biomarkers and inflammatory markers in patients after orthotopic liver transplantation from deceased donors.

METHODS

In total, 100 patients were evaluated for short-term complications within 10 days after orthotopic liver transplantation from deceased donors. Blood samples were collected before surgery, immediately after the end of the surgical procedure, and 1 day and 3, 5, and 7 days later. Plasma levels of total keratin 18, keratin 18 fragments, interleukin 6, tumor necrosis factor α, and soluble intercellular adhesion molecule 1 were measured.

RESULTS

Total keratin 18 was demonstrated to be favorable in its prognostic value for early identification of a complicated course in comparison to routine markers of liver impairment (e.g., aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase). In contrast, inflammation markers (e.g., interleukin 6, tumor necrosis factor α and soluble intercellular adhesion molecule 1) were unsuitable for predicting early complications after liver transplantation from deceased donors.

CONCLUSIONS

For early identification of patients at high risk for complications, the implementation of total keratin 18 measurements in routine diagnostics after orthotopic liver transplantation from deceased donors should be taken into consideration.

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.

Effects of fluoxetine on the oxidative status of peripheral blood leucocytes of restraint-stressed mice

Emotional stress can be viewed as a cause of adverse circumstances that induces a wide range of biochemical and behavioural changes. Oxidative stress is a critical route of damage in various psychological stress-induced disorders such as depression. Antidepressants are widely prescribed to treat these conditions; however, no animal study has investigated the effect of selective serotonin reuptake inhibitors (SSRIs) on the levels of intracellular reactive oxygen species in peripheral blood leucocytes of stressed mice. In this study, mice were immobilized for a period of 6 hr. Fluoxetine (5 mg/kg of body-weight) was administered 30 min. before subjecting the animals to acute stress. The level of intracellular reactive oxygen species in leucocytes of the peripheral blood of stressed mice was investigated using a 2',7'-dichlorofluorescein diacetate probe, and the antioxidant response of fluoxetine was evaluated by superoxide dismutase, diaphorase, catalase and reduced glutathione. Our results show that restraint stress significantly increases the generation of reactive oxygen species in the peripheral defence cells. Treatment with fluoxetine partially reverses the adverse effects of stress. The improvement in cellular oxidative status may be an important mechanism underlying the protective pharmacological effects of fluoxetine, which are clinically observed in the treatment of depressive disorders.

IL-6 serum levels predict postoperative morbidity in gastric cancer patients

BACKGROUND

Despite progress in surgical techniques and perioperative care, gastrectomy remains a procedure of significant morbidity. Several scoring systems and clinical measures have been adopted to predict postoperative complications in gastric cancer patients. The aim of this study was to investigate whether high serum levels of interleukin 6 (IL-6) in the early postoperative period may be a prognostic factor of postoperative morbidity.

METHODS

A group of 99 consecutive patients with resectable gastric cancer were enrolled. The mean age was 62.9 years and the male/female ratio was 72:27. Subtotal gastric resection was performed in 22 patients and total gastric resection in 77. The IL-6 serum level was measured on the 1st postoperative day (POD).

RESULTS

Complications were recorded in 28 patients (28.3%). The observed case-fatality rate was 3.03%. An IL-6 serum level of >288.7 pg/ml on the 1st POD in univariate and multivariate Cox proportional hazard models was an independent prognostic factor for overall complications and infective complications.

CONCLUSION

Our study showed an association between perioperative IL-6 serum levels and postoperative morbidity in gastric cancer patients. The IL-6 serum level on the 1st POD was shown to be an independent prognostic factor for both overall complications and infective complications.

Early post-operative measurement of cytokine plasma levels combined with pre-operative bilirubin levels identify high-risk patients after liver resection

Identification of patients at risk of a complicated course after liver resection is crucial for adapting post-operative care. In the present study, we investigated the diagnostic value of the plasma levels of various cytokines obtained immediately after surgery. IL-6, IL-10, IL-8, monokine induced by interferon-γ (MIG), monocyte chemotactic protein-1 (MCP-1) and interferon-inducible protein-10 (IP-10) concentrations were measured in 26 patients after liver resection using a cytometric bead assay and were correlated with liver function, resectate weight, surgery duration, ischemia/reperfusion, hospitalization time and occurrence of complications. Patients with post-surgical complications showed distinctive patterns of IL-6 and IL-8 as early as minutes to hours after surgery. In addition, although pre-operative bilirubin in most patients remained within the normal range, a cut-off of 1 mg/dl separated the patients into groups with different profiles of IL-6, IL-8, and MCP-1 secretion and different likelihoods of experiencing post-operative complications (bilirubin levels ≥1.0 vs. <1.0 mg/dl; IL-6 (4 h): 701 vs. 265; IL-8 (6 h): 262 vs. 97 pg/ml; p<0.05 for both). Extended hospitalization, related to delayed recovery, was correlated with increased IL-8 and MCP-1 immediately after surgery. In conclusion, on the basis of these observations, we suggest that early measurement of post-operative levels of MCP-1, IL-6, and IL-8 can be used to identify individuals at risk of post-operative complications immediately after liver surgery.

Release of danger signals during ischemic storage of the liver: a potential marker of organ damage?

Liver grafts suffer from unavoidable injury due to ischemia and manipulation before implantation. Danger signals such as high-mobility group box -1(HMGB1) and macrophage migration inhibitory factor (MIF) play a pivotal role in the immune response. We characterized the kinetics of their release into the effluent during cold/warm ischemia and additional manipulation-induced mechanical damage. Furthermore, we evaluated the relationship between HMGB1/MIF release and ischemic/mechanical damage. Liver enzymes and protein in the effluent increased with increasing ischemia time. HMGB1/MIF- release correlated with the extent of hepatocellular injury. With increasing ischemia time and damage, HMGB1 was translocated from the nucleus to the cytoplasma as indicated by weak nuclear and strong cytoplasmic staining. Enhancement of liver injury by mechanical damage was indicated by an earlier HMGB1 translocation into the cytoplasm and earlier release of danger signals into the effluent. Our results suggest that determination of HMGB1 and MIF reflects the extent of ischemic injury. Furthermore, HMGB1 and MIF are more sensitive than liver enzymes to detect the additional mechanical damage inflicted on the organ graft during surgical manipulation.

Immunosuppression following surgical and traumatic injury

Severe sepsis and organ failure are still the major causes of postoperative morbidity and mortality after major hepatobiliary pancreatic surgery. Despite recent progress in understanding the immune conditions of abdominal sepsis, the postoperative incidence of septic complications after major visceral surgery remains high. This review focuses on the clinical and immunological parameters that determine the risk of the development and lethal outcome of postoperative septic complication following major surgery and trauma. A review of the literature indicates that surgical and traumatic injury profoundly affects the innate and adaptive immune responses, and that a marked suppression in cell-mediated immunity following an excessive inflammatory response appears to be responsible for the increased susceptibility to subsequent sepsis. The innate and adaptive immune responses are initiated and modulated by pathogen-associated molecular-pattern molecules and by damage-associated molecular-pattern molecules through the pattern-recognition receptors. Suppression of cell-mediated immunity may be caused by multifaceted cytokine/inhibitor profiles in the circulation and other compartments of the host, excessive activation and dysregulated recruitment of polymorphonuclear neutrophils, induction of alternatively activated or regulatory macrophages that have anti-inflammatory properties, a shift in the T-helper (Th)1/Th2 balance toward Th2, appearance of regulatory T cells, which are potent suppressors of the innate and adaptive immune system, and lymphocyte apoptosis in patients with sepsis. Recent basic and clinical studies have elucidated the functional effects of surgical and traumatic injury on the immune system. The research studies of interest may in future aid in the selection of appropriate therapeutic protocols.

The role of serum interleukin-8 in hepatic resections

PURPOSE

Interleukin-8 (IL-8) is a neutrophil chemotactic factor, which is associated with some inflammatory diseases and various types of surgical stress. The aim of this study was to investigate whether the early postoperative serum IL-8 level may potentially be a new indicator of a surgical stress in patients undergoing a hepatic resection.

METHODS

The serum IL-8 levels were measured in 37 patients who underwent a hepatectomy. The serum IL-8 levels were serially measured using an enzyme-linked immunosorbent assay both before and after a hepatic resection. In addition, the correlation between the postoperative IL-8 value and several clinical variables were examined.

RESULTS

The mean level of IL-8 significantly increased immediately after the operation (P < 0.01 vs before the operation) and decreased on the first postoperative day (POD 1, P < 0.05 vs after the operation). The early postoperative IL-8 levels positively correlated with the length of the procedure (r = 0.383; P < 0.05), the estimated blood loss (r = 0.483; P < 0.01) and the serum bilirubin level on POD 1 (r = 0.390; P < 0.05), and inversely correlated with the white blood cell counts (r = -0.388; P < 0.05) and lymphocyte counts on POD 1 (r = -0.424; P < 0.05). In a comparison of the postoperative IL-8 levels with the surgical factors, there was a significant difference in the extension of the resection (P < 0.05) and in blood transfusion. The patients with a fever of more than 38 degrees C showed higher levels of IL-8 immediately after the operation than those without fever (P < 0.01).

CONCLUSIONS

The early postoperative serum IL-8 level was found to correlate with the degree of the severity of surgery in patients undergoing a hepatic resection, and it is also considered to be a new indicator of surgical stress and liver injury.

Neutrophil phenotype and function in partial hepatectomy in man

PURPOSE

Hepatic resections are still associated with considerable morbidity mainly because of postoperative infection. Adequate function of neutrophils is a crucial element in host defense. The aim of the study was to characterize neutrophils during partial hepatectomy.

METHODS

Fourteen patients undergoing partial liver resection were enrolled. Twenty-four hours pre-, intra- (after induction of anesthesia, after preparation of the liver, and 15 min after release of the Pringle maneuver), as well as postoperatively (3 h after Pringle; 24, 48, and 120 h after surgery), blood samples were obtained. In addition, healthy volunteers (n = 5) were investigated. Adhesion molecules (CD 62, CD 18), Fcy receptors (CD 16, CD 32), and phagocytosis by neutrophils were characterized by fluorescence-activated cell sorter analysis. Spontaneous and stimulated (formyl-methionyl-leucyl-phenylalanine) oxygen radical generation was measured by lucigenin-enhanced chemiluminescence.

RESULTS

Numeric upregulation of CD 62 and CD 18 on neutrophils was seen before the use of Pringle maneuver and persisted thereafter (p < 0.05). Spontaneous numeric expression of Fcy receptors (CD16 and CD 32) was unchanged during liver dissection but downregulated after Pringle maneuver was opened (p < 0.05). Although numeric Fcy receptors were downregulated, phagocytosis of heterologous opsonized Escherichia coli bacteria by neutrophils was unaffected. Spontaneous oxygen radical production peaked sharply 15 min after release of the Pringle maneuver (p < 0.05), contrary to stimulated oxygen radical production, which was depressed 3 h after the release of the Pringle maneuver (ns).

CONCLUSIONS

Uneventful partial hepatectomy in man resulted already in a significant change in the phenotype but in less significant changes in the functions of neutrophils.

Consequences of surgical stress on the kinetics of skin wound healing: partial hepatectomy delays and functionally alters dermal repair

The objective was to determine the significance of surgical trauma in dermal wound healing. Using intravital microscopy, we analyzed the healing kinetics of full-thickness dermal wounds in the ears of SKH1 mice. Partial hepatectomy (pHx) simulated major surgical trauma, while laparotomy only served as a sham operation (sham). Animals without abdominal surgery served as controls (control). Laparotomy wounds were analyzed for biomechanical qualities and collagen deposition. Morphological characterization of skin repair was performed by histology/immunohistochemistry. In vitro cell assays assessed the paracrine effects of surgical stress. PHx caused a transient increase in tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 levels and led to weight loss, reflecting the host's overall response to surgery. Wound closure in pHx animals was delayed vs. control and sham animals, as indicated by significantly lower values of epithelialization and neovascularization over 10 days. Ear wound histology further revealed a provisional wound matrix with a reduced microvessel density. Moreover, pHx-laparotomy wounds showed a reduced bursting strength coexisting with significantly decreased collagen content. PHx and sham serum caused a significant alteration in in vitro fibroblast viability. Skin healing is dependent on the extent of surgery and is influenced by its paracrine effects. Therefore, considerable effort should be focused on the development of strategies limiting surgery-associated perturbations of dermal repair.

Feasibility of randomized controlled trials in liver surgery using surgery-related mortality or morbidity as endpoint

BACKGROUND

There is a shortage of randomized controlled trials (RCTs) on which to base guidelines in liver surgery. The feasibility of conducting an adequately powered RCT in liver surgery using the dichotomous endpoints surgery-related mortality or morbidity was examined.

METHODS

Articles published between January 2002 and November 2007 with mortality or morbidity after liver surgery as primary endpoint were retrieved. Sample size calculations for a RCT aiming to show a relative reduction of these endpoints by 33, 50 or 66 per cent were performed.

RESULTS

The mean operative mortality rate was 1.0 per cent and the total morbidity rate 28.9 per cent; mean rates of bile leakage and postresectional liver failure were 4.4 and 2.6 per cent respectively. The smallest numbers of patients needed in each arm of a RCT aiming to show a 33 per cent relative reduction were 15 614 for operative mortality, 412 for total morbidity, 3446 for bile leakage and 5924 for postresectional liver failure.

CONCLUSION

The feasibility of conducting an adequately powered RCT in liver surgery using outcomes such as mortality or specific complications seems low. Conclusions of underpowered RCTs should be interpreted with caution. A liver surgery-specific composite endpoint may be a useful and clinically relevant solution to pursue.

The impact of carbon dioxide pneumoperitoneum on liver regeneration after liver resection in a rat model

BACKGROUND

In recent years, laparoscopic hepatic resection is performed by an increasing number of surgeons. Despite many advantages of the laparoscopic procedure, it is unclear whether the pneumoperitoneum affects the postoperative liver regeneration after liver resection. The current study aimed to investigate the influence of a carbon dioxide (CO(2)) pneumoperitoneum on liver regeneration in a rat model.

METHODS

In this study, 60 male Wistar rats were subjected to 70% partial hepatic resection. Of these 60 animals, 30 underwent preoperative pneumoperitoneum at 9 mmHg for 60 min. After hepatic resection, the rats were killed at 12, 24, and 48 h, and on days 4 and 7. The outcome parameters were hepatocellular injury (plasma aminotransferases), oxidative stress (plasma malondialdehyde), interleukin-6 (IL-6), and liver regeneration (mitotic index, KI-67; regenerating liver mass).

RESULTS

The mitotic index was significantly lower in the pneumoperitoneum group than in the group without pneumoperitoneum at all time points (p < 0.05). In the pneumoperitoneum group, KI-67 was significantly lower on day 4 (p < 0.05). The liver regeneration rate was significantly lower for the animals with pneumoperitoneum on days 2 and 4 (p < 0.05). The postoperative hepatocellular injury was significantly greater after pneumoperitoneum at 12, 24, and 48 h (p < 0.05). Plasma malondialdehyde and IL-6 were significantly higher in the pneumoperitoneum group at 24 h and on day 4 (p < 0.05).

CONCLUSION

This study showed that pneumoperitoneum before extended liver resection impaired postoperative liver regeneration. Oxidative stress reaction and hepatocellular damage was markedly higher after pneumoperitoneum. Further investigations, especially with patients that have impaired liver function, are necessary for clinical consequences to be drawn from these results.

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

Liver failure is a dreaded and often fatal complication that sometimes follows a partial hepatic resection. This article reviews the definition, incidence, pathogenesis, risk factors, risk assessment, prevention, clinical features and treatment of post-resectional liver failure (PLF). A systematic, computerized search was performed using key words related to 'partial hepatic resection' and 'liver failure' to review most relevant literature about PLF published in the last 20 years. The reported incidence of PLF ranges between 0.7 and 9.1%. An inadequate quantity or quality of residual liver mass are key events in its pathogenesis. Major risk factors are the presence of comorbid conditions, pre-existent liver disease and small remnant liver volume (RLV). It is essential to identify these risk factors during the pre-operative assessment that includes evaluation of liver volume, anatomy and function. Preventive measures should be applied whenever possible as curative treatment options for PLF are limited. These preventive measures intend to increase RLV and protect remnant liver function. Management principles focus on support of end-organ and liver function. Further research is needed to elucidate the exact pathogenesis of PLF and to develop and validate adequate treatment options.

Remote renal injury following partial hepatic ischemia/reperfusion injury in rats

Liver ischemia/reperfusion has been shown to result in injury of remote organs such as the heart and lungs. Whether or not acute liver injury also results in kidney injury has so far not been adequately addressed. In anesthetized Wistar rats, partial (70%) normothermic hepatic ischemia was applied for 75 min. After 24 h of reperfusion, renal injury was assessed by histology, creatinine and blood urea nitrogen (BUN) serum concentrations, renal expression of proinflammatory genes [quantitative real-time polymerase chain reaction (qRT-PCR)], caspase-3 activation (Western blot), and neutrophil accumulation (myeloperoxidase assay). Twenty-four hours after hepatic ischemia, creatinine (0.57+/-0.06 vs. 0.32+/-0.04 mg/dL) and BUN (40.7+/-15.3 vs. 14.3+/-2.0 mg/dL) were increased when compared to sham. qRT-PCR revealed higher renal intercellular adhesion molecule-1 gene expression following hepatic ischemia (166+/-45% when compared to sham) but no differences in renal monocyte chemoattractant protein-1, macrophage inflammatory protein-2, and inducible NO synthase expression. In both groups, kidneys showed no morphological damage and no increase in caspase-3 and myeloperoxidase activity. Severe hepatic ischemia results in a moderate impairment of renal function in rats but does not trigger an inflammatory response in the kidney and does not result in morphological damage of the kidney.

Preoperative high-dose steroid administration attenuates the surgical stress response following liver resection: results of a prospective randomized study

BACKGROUND/PURPOSE

Major abdominal surgery such as liver resection is associated with an excessive hyperinflammatory response and transient immunosuppression. We investigated the immunomodulating effect of preoperative pulse administration of high-dose methylprednisolone in patients undergoing hepatic resection without pedicle clamping.

METHODS

Twenty patients who underwent hepatic resection were randomized into two groups: a steroid group (n = 10), in which patients were given 30 mg/kg per body weight (BW) methylprednisolone intravenously, and a control group (n = 10), in which patients received a placebo (sodium chloride) infusion. The main outcome parameter to assess systemic stress was the serum plasma level of interleukin-6 (IL-6). To evaluate cell-mediated immune function, human leukocyte antigen-DR (HLA-DR) expression on peripheral blood monocytes and lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-alpha) release by peripheral monocytes was measured. Other investigated serum parameters included C-reactive protein (CRP), total bilirubin, alanine aminotransferase (ALT), prothrombin time (PT)-INR, and cytokines such as IL-8 and IL-10 and TNF-alpha. Postoperative convalescence, complication rate, and length of hospital stay were compared between the groups.

RESULTS

Postoperative plasma concentrations of IL-6 (days 1 and 2), IL-8 (days 2 and 3), and CRP (days 1-4) were significantly lower in the steroid than in the control group. The total bilirubin concentration was significantly lower on day 6 in the steroid than in the control group. Four hours after surgery, LPS-induced TNF-alpha secretion was significantly reduced in the steroid group, but it increased rapidly during the following days. HLA-DR, ALT, and PT-INR levels were not different between the two groups. The postoperative hospital stay in the steroid group was significantly lower compared to that in the control group (mean, 10.5 days versus 14.8 days; P < 0.05). No differences were found in the convalescence score or postoperative complication rate.

CONCLUSIONS

Intravenous methylprednisolone administration before hepatic resection significantly reduced systemic inflammatory cytokine release. No adverse effect on immunity was noted due to the methylprednisolone. We found no significant difference in the convalescence score, but a significantly shorter hospital stay in the steroid group. Further studies with more patients are needed to elucidate the clinical impact of preoperative steroid bolus therapy in liver surgery.

Liver resection-associated macrophage inflammatory protein-2 stimulates engraftment but not growth of colorectal metastasis at extrahepatic sites

BACKGROUND

Previous studies have shown that liver resection enhances intrahepatic engraftment of CXCR-2-expressing colorectal cancer cells by the action of the CXC chemokine macrophage inflammatory protein (MIP)-2. Herein we studied how liver resection-associated MIP-2 affects extrahepatic tumor cell engraftment and whether MIP-2 also stimulates the growth of already established metastases.

MATERIALS AND METHODS

Green fluorescent protein-transfected CT26.WT colorectal cancer cells were implanted into dorsal skinfold chambers of syngeneic BALB/c mice. Additionally, all animals underwent a 30% hepatectomy. To study MIP-2 in extrahepatic tumor cell engraftment, animals were treated with an anti-MIP-2 antibody, starting at the day of tumor cell implantation. To study MIP-2 in established metastases, anti-MIP-2 treatment was initiated at day 5 after tumor cell implantation. Hepatectomized animals without neutralization of MIP-2 served as controls. Tumor vascularization and growth as well as tumor cell migration, proliferation, apoptosis, and CXCR-2 expression were studied over 14 days using intravital fluorescence microscopy, histology, and immunohistochemistry.

RESULTS

Functional inhibition of MIP-2 significantly delayed extrahepatic tumor cell engraftment but not the growth of established metastases. The initial delay of engraftment was associated with a compensatory stimulation of vascularization and tumor cell migration when compared to controls (P < 0.05). Further, inhibition of tumor cell engraftment by initial anti-MIP-2 treatment was associated with a significant (P < 0.05) reduction of CXCR-2 expression and tumor cell apoptosis.

CONCLUSION

Our study indicates that MIP-2 is involved in extrahepatic engraftment of CT.26 colorectal cancer cells. The MIP-2/CXCR-2 signaling pathway may be a promising target for early antitumor therapy in patients undergoing liver resection.