Inflammatory response and oxidative stress during liver resection

Is prolonged operative time associated with postoperative complications in liver surgery? An international multicentre cohort study of 5424 patients

BACKGROUND

The relation between operative time and postoperative complications in liver surgery is unclear. The aim of this study is to assess the impact of operative time on the development of postoperative complications in patients who underwent minimally invasive or open liver resections of various anatomical extent and technical difficulty levels.

METHODS

In this retrospective cohort study, patients that underwent a right hemihepatectomy (RH), technically major resection (anatomically minor resection in segment 1, 4a, 7 or 8; TMR) or left lateral sectionectomy (LLS) between 2000 and 2022 were extracted from a multicenter database comprising the prospectively maintained databases of 31 centers in 13 countries. Minimally invasive procedures performed during the learning curve were omitted. Logistic regression models, performed separately for 9 different groups based on stratification by procedure type and allocated surgical approach, were used to assess the association between the fourth quartile of operative time (25% of patients with the longest operative time) and postoperative complications.

RESULTS

Overall, 5424 patients were included: 1351 underwent RH (865 open, 373 laparoscopic and 113 robotic), 2821 TMR (1398 open, 1225 laparoscopic and 198 robotic), and 1252 LLS (241 open, 822 laparoscopic and 189 robotic). After adjusting for potential confounders (age, BMI, gender, ASA grade, previous abdominal surgery, disease type and extent, blood loss, Pringle, intraoperative transfusions and incidents), the fourth quartile of operative time, compared to the first three quartiles, was associated with an increased risk of postoperative complications after open, laparoscopic and robotic TMR (aOR 1.35, p = 0.031; aOR 1.74, p = 0.001 and aOR 3.11, p = 0.014, respectively), laparoscopic and robotic RH (aOR 1.98, p = 0.018 and aOR 3.28, p = 0.055, respectively) and solely laparoscopic LLS (aOR 1.69, p = 0.019).

CONCLUSIONS

A prolonged operative time is associated with an increased risk of postoperative complications, although it remains to be defined if this is a causal relationship.

A prognostic model for hepatocellular carcinoma patients based on polyunsaturated fatty acid-related genes

OBJECTIVE

Polyunsaturated fatty acids (PUFAs) have attracted increasing attention for their role in liver cancer development. The objective of this study is to develop a prognosis prediction model for patients with liver cancer based on PUFA-related metabolic gene characteristics.

METHOD

Transcriptome data and clinical data were obtained from public databases, while gene sets related to PUFAs were acquired from the gene set enrichment analysis (GSEA) database. Univariate Cox analysis was conducted on the training set, followed by LASSO logistic regression and multivariate Cox analysis on genes with p < .05. Subsequently, the stepwise Akaike information criterion method was employed to construct the model. The high- and low-risk groups were divided based on the median score, and the model's survival prediction ability, diagnostic efficiency, and risk score distribution of clinical features were validated. The above procedures were also validated in the validation set. Immune infiltration levels were evaluated using four algorithms, and the immunotherapeutic potential of different groups was explored. Significant enrichment pathways among different groups were selected based on the GSEA algorithm, and mutation analyses were conducted. Nomogram prognostic models were constructed by incorporating clinical factors and risk scores using univariate and multivariate Cox regression analysis, validated through calibration curves and clinical decision curves. Additionally, sensitivity analysis of drugs was performed to screen potential targeted drugs.

RESULTS

We constructed a prognostic model comprising eight genes (PLA2G12A, CYP2C8, ABCCI, CD74, CCR7, P2RY4, P2RY6, and YY1). Validation across multiple datasets indicated the model's favorable prognostic prediction ability and diagnostic efficiency, with poorer grading and staging observed in the high-risk group. Variations in mutation status and pathway enrichment were noted among different groups. Incorporating Stage, Grade, T.Stage, and RiskScore into the nomogram prognostic model demonstrated good accuracy and clinical decision benefits. Multiple immune analyses suggested greater benefits from immunotherapy in the low-risk group. We predicted multiple targeted drugs, providing a basis for drug development.

CONCLUSION

Our study's multifactorial prognostic model across multiple datasets demonstrates good applicability, offering a reliable tool for personalized therapy. Immunological and mutation-related analyses provide theoretical foundations for further research. Drug predictions offer important insights for future drug development and treatment strategies. Overall, this study provides comprehensive insights into tumor prognosis assessment and personalized treatment planning.

The Interplay between Perioperative Oxidative Stress and Hepatic Dysfunction after Human Liver Resection: A Prospective Observational Pilot Study

Post-hepatectomy liver failure (PHLF) remains the major contributor to death after liver resection. Oxidative stress is associated with postoperative complications, but its impact on liver function is unclear. This first in-human, prospective, single-center, observational pilot study evaluated perioperative oxidative stress and PHLF according to the ISGLS (International Study Group for Liver Surgery). Serum 8-isoprostane, 4-hydroxynonenal (4-HNE), total antioxidative capacity, vitamins A and E, and intraoperative, sequential hepatic tissue 4-HNE and UCP2 (uncoupling protein 2) immunohistochemistry (IHC) were assessed. The interaction with known risk factors for PHLF and the predictive potential of oxidative stress markers were analyzed. Overall, 52 patients were included (69.2% major liver resection). Thirteen patients (25%) experienced PHLF, a major factor for 90-day mortality (23% vs. 0%; p = 0.013). Post-resection, pro-oxidative 8-isoprostane significantly increased (p = 0.038), while 4-HNE declined immediately (p < 0.001). Antioxidative markers showed patterns of consumption starting post-resection (p < 0.001). Liver tissue oxidative stress increased stepwise from biopsies taken after laparotomy to post-resection in situ liver and resection specimens (all p < 0.001). Cholangiocarcinoma patients demonstrated significantly higher serum and tissue oxidative stress levels at various timepoints, with consistently higher preoperative values in advanced tumor stages. Combining intraoperative, post-resection 4-HNE serum levels and in situ IHC early predicted PHLF with an AUC of 0.855 (63.6% vs. 0%; p < 0.001). This was also associated with grade B/C PHLF (36.4% vs. 0%; p = 0.021) and 90-day mortality (18.2% vs. 0%; p = 0.036). In conclusion, distinct patterns of perioperative oxidative stress levels occur in patients with liver dysfunction. Combining intraoperative serum and liver tissue markers predicts subsequent PHLF. Cholangiocarcinoma patients demonstrated pronounced systemic and hepatic oxidative stress, with increasing levels in advanced tumor stages, thus representing a worthwhile target for future exploratory and therapeutic studies.

Innovation and disruptive science determine the future of cardiothoracic surgery

One of the currently most asked questions in the field of medicine is how any specialty in the future will evolve to ensure better health for the patients by using current, unparalleled developments in all areas of science. This article will give an overview of new and evolving strategies for cardiothoracic (CT) surgery that are available today and will become available in the future in order to achieve this goal. In the founding era of CT surgery in the 1950s and 1960s, there was tremendous excitement about innovation and disruptive science, which eventually resulted in a completely new medical specialty, i.e. CT surgery. Entirely new treatment strategies were introduced for many cardiovascular diseases that had been considered incurable until then. As expected, alternative techniques have evolved in all fields of science during the last few decades, allowing great improvements in diagnostics and treatment in all medical specialties. The future of CT surgery will be determined by an unrestricted and unconditional investment in innovation, disruptive science and our own transformation using current achievements from many other fields. From the multitude of current and future possibilities, I will highlight 4 in this review: improvements in our current techniques, bringing CT surgery to low- and middle-income countries, revolutionizing the perioperative period and treating as yet untreatable diseases. These developments will allow us a continuation of the previously unheard-of treatment possibilities provided by ingenious innovations based on the fundamentals of CT surgery.

Gliosis induction on locus coeruleus in a living liver donor experimental model: A brief review

Living Donor Liver Transplantation (LDLT) is a promising approach to treating end-stage liver diseases, however, some post-operatory complications such as pneumonia, bacteremia, urinary tract infections, and hepatic dysfunction have been reported. In murine models using partial hepatectomy (PHx), a model that emulates LDLT, it has been determined that the synthesis of hepatic cell proliferation factors that are associated with noradrenaline synthesis are produced in locus coeruleus (LC). In addition, studies have shown that PHx decreases GABA and 5-HT2A receptors, promotes loss of dendritic spines, and favors microgliosis in rat hippocampus. The GABA and serotonin-altered circuits suggest that catecholaminergic neurons such as dopamine and noradrenaline neurons, which are highly susceptible to cellular stress, can also be damaged. To understand post-transplant affections and to perform well-controlled studies it is necessary to know the potential causes that explain as a liver surgical procedure can produce brain damage. In this paper, we review several cellular processes that could induce gliosis in LC after rat PHx.

The tumor microenvironment in the postsurgical liver: Mechanisms and potential targets of postoperative recurrence in human hepatocellular carcinoma

Surgery remains to be the mainstay of treatment for hepatocellular carcinoma (HCC). Nonetheless, its therapeutic efficacy is significantly impaired by postoperative recurrence, which occurs in more than half of cases as a result of intrahepatic metastasis or de novo tumorigenesis. For decades, most therapeutic strategies on inhibiting postoperative HCC recurrence have been focused on the residual tumor cells but satisfying therapeutic outcomes are barely observed in the clinic. In recent years, a better understanding of tumor biology allows us to shift our focus from tumor cells toward the postoperative tumor microenvironment (TME), which is gradually identified to play a pivotal role in tumor recurrence. In this review, we describe various surgical stress and surgical perturbation on postoperative TME. Besides, we discuss how such alternations in TME give rise to postoperative recurrence of HCC. Based on its clinical significance, we additionally highlight the potential of the postoperative TME as a target for postoperative adjuvant therapeutics.

Does inclusion of bioactive n-3 PUFAs in parenteral nutrition benefit postoperative patients undergoing liver surgery? A systematic review and meta-analysis of randomised control trials

OBJECTIVES

This meta-analysis aims to evaluate the effect of n-3 polyunsaturated fatty acids (PUFAs) as a part of parenteral nutrition in patients undergoing liver surgery.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, the Cochrane Central Register of Controlled Trials, Springer link, Web of Science, China National Knowledge Infrastructure and VIP Database.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) and evaluated the outcomes of liver function, inflammatory reaction, the influence of certain markers of the immune system, and specific clinical indexes for patients undergoing liver surgery and receiving parenteral nutrition with n-3 PUFAs.

DATA EXTRACTION AND SYNTHESIS

The Cochrane Collaboration's tool was used to assess the risk of bias for each study. Findings were summarised in Grades of Recommendation, Assessment, Development and Evaluation evidence profiles and synthesised qualitatively.

RESULTS

Eight RCTs, including 748 patients (trial: 374; control: 374), were included in the meta-analysis. Compared with patients in the control group, the patients in the n-3 PUFA group who underwent liver surgery had significantly lower aspartate aminotransferase (mean difference, MD -42.72 (95% CI -71.91 to -13.52); p=0.004), alanine aminotransferase (MD -38.90 (95% CI -65.44 to -12.37); p=0.004), white cell count (MD -0.93 (95% CI -1.60 to -0.26); p=0.007) and IL-6 (MD -11.37 (95% CI -14.62 to -8.13); p<0.00001) levels and a higher albumin level (MD 0.42 (95% CI 0.26 to 0.57); p<0.00001). They also had fewer infection complications (OR 0.44 (95% CI 0.28 to 0.68); p=0.0003) and a shorter duration of hospital stay (MD -2.17 (95% CI -3.04 to -1.3); p<0.00001) than the controls. However, there were no significant differences in terms of total bilirubin, TNF-α, IL-2, IgA, IgG, IgM and CD3, biliary leakage and mortality between the two groups.

CONCLUSIONS

We found that n-3 PUFAs can benefit patients undergoing liver surgery by improving liver function and certain clinical indexes and decreasing related inflammation factors. However, there are limited RCTs on the application of n-3 PUFAs for patients undergoing liver surgery. Further evidence of the benefit of n-3 PUFAs in these patients warrants further exploration.

Uncoupled redox stress: how a temporal misalignment of redox-regulated processes and circadian rhythmicity exacerbates the stressed state

Diurnal and seasonal rhythmicity, entrained by environmental and nutritional cues, is a vital part of all life on Earth operating at every level of organization; from individual cells, to multicellular organisms, whole ecosystems and societies. Redox processes are intrinsic to physiological function and circadian regulation, but how they are integrated with other regulatory processes at the whole-body level is poorly understood. Circadian misalignment triggered by a major stressor (e.g. viral infection with SARS-CoV-2) or recurring stressors of lesser magnitude such as shift work elicit a complex stress response that leads to desynchronization of metabolic processes. This in turn challenges the system's ability to achieve redox balance due to alterations in metabolic fluxes (redox rewiring). We infer that the emerging 'alternative redox states' do not always revert readily to their evolved natural states; 'Long COVID' and other complex disorders of unknown aetiology are the clinical manifestations of such rearrangements. To better support and successfully manage bodily resilience to major stress and other redox challenges needs a clear perspective on the pattern of the hysteretic response for the interaction between the redox system and the circadian clock. Characterization of this system requires repeated (ideally continuous) recording of relevant clinical measures of the stress responses and whole-body redox state (temporal redox phenotyping). The human/animal body is a complex 'system of systems' with multi-level buffering capabilities, and it requires consideration of the wider dynamic context to identify a limited number of stress-markers suitable for routine clinical decision making. Systematically mapping the patterns and dynamics of redox biomarkers along the stressor/disease trajectory will provide an operational model of whole-body redox regulation/balance that can serve as basis for the identification of effective interventions which promote health by enhancing resilience.

Perioperative redox changes in patients undergoing hepato-pancreatico-biliary cancer surgery

BACKGROUND

Tissue injury induces inflammation and the surgical stress response, which are thought to be central to the orchestration of recovery or deterioration after surgery. Enhanced formation of reactive oxygen and nitrogen species accompanies the inflammatory response and triggers separate but integrated reduction/oxidation (redox) pathways that lead to oxidative and/or nitrosative stress (ONS). Quantitative information on ONS in the perioperative period is scarce. This single-centre exploratory study investigated the effects of major surgery on ONS and systemic redox status and their potential associations with postoperative morbidity.

METHODS

Blood was collected from 56 patients at baseline, end of surgery (EoS) and the first postoperative day (day-1). Postoperative morbidity was recorded using the Clavien-Dindo classification and further categorised into minor, moderate and severe. Plasma/serum measures included markers of lipid oxidation (thiobarbituric acid-reactive substances; TBARS, 4-hydroxynonenal; 4-HNE, 8-iso-prostaglandin F_2⍺; 8-isoprostanes). Total reducing capacity was measured using total free thiols (TFTs) and ferric-reducing ability of plasma (FRAP). Nitric oxide (NO) formation/metabolism was measured using cyclic guanosine monophosphate (cGMP), nitrite, nitrate and total nitroso-species (RxNO). Interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-⍺) were measured to evaluate inflammation.

RESULTS

Both oxidative stress (TBARS) and nitrosative stress (total nitroso-species) increased from baseline to EoS (+14%, P = 0.003 and +138%, P < 0.001, respectively), along with an increase in overall reducing capacity (+9%, P = 0.03) at EoS and protein-adjusted total free thiols (+12%, P = 0.001) at day-1 after surgery. Nitrite, nitrate and cGMP concentrations declined concomitantly from baseline to day-1. Baseline nitrate was 60% higher in the minor morbidity group compared to severe (P = 0.003). The increase in intraoperative TBARS was greater in severe compared to minor morbidity (P = 0.01). The decline in intraoperative nitrate was more marked in the minor morbidity group compared to severe (P < 0.001), whereas the cGMP decline was greatest in the severe morbidity group (P = 0.006).

CONCLUSION

In patients undergoing major HPB surgery, intraoperative oxidative and nitrosative stress increased, with a concomitant increase in reductive capacity. Baseline nitrate was inversely associated with postoperative morbidity, and the hallmarks of poor postoperative outcome include changes in both oxidative stress and NO metabolism.

Markers of inflammation in invasive treatment of coloractal cancer liver metastases

Background. In 25–30% of patients with colorectal cancer (CRC) who have no visible signs of metastasis at the time of surgery, metastases are detected within 5 years. Among the options for local treatment of metastatic liver lesions in patients with CRC, various resection options and minimally invasive methods, in particular radiofrequency ablation (RFA), occupy a prominent place. The inflammatory response caused by surgery is a factor that can negatively affect the course of tumor disease. The inflammatory responses of the body, as well as markers for their evaluation and prognosis in the treatment of CRC metastases, have not yet been sufficiently studied. Purpose – to study the dynamics of inflammatory markers in the invasive treatment of colorectal cancer liver metastases to select the most informative markers for assessing and predicting the degree of inflammatory response. Materials and methods. Clinical and laboratory examination was carried out in 18 patients with CRC during the treatment of metastases in the liver, adenocarcinoma was determined in all patients during histological examination. The examination was carried out in three stages: the day before RFA or resection, on days 3 and 14 after the intervention. Serum levels of insulin and IL-6 were measured using an enzyme-linked immunosorbent assay, and levels of C-reactive protein and ferritin were determined using an automatic biochemical analyser. Results and discussion. Markers of inflammation in patients with CRC with liver metastases after invasive intervention were identified. A significant increase in the levels of circulating C-reactive protein (CRP), IL-6 and ferritin was detected along with an increase in the insulin resistance index (HOMA-IR) on day 3 after RFA and resection. The increase in IL-6 was 2-fold higher and the HOMA-IR index was 1.5-fold higher after resection compared with RFA. Patients after RFA showed an approach of indicators to baseline values on day 14 of the study, while CRP, ferritin, IL-6 and insulin levels in patients after resection decreased by only 20–30% at the same time same period. This is consistent with other studies. In particular, elevated CRP levels are considered as a risk factor for the appearance and progression of CRC.There is also evidence that in patients with operable CRC, preoperative IL-6 levels affect the risk of recurrence. Strong evidence suggests that ferritin is a key mediator of immune dysregulation through direct immunosuppressive and pro-inflammatory effects. The accumulated data from the literature and our own results suggest the role of CRP, IL-6 and ferritin in postoperative inflammatory states as mediators and biomarkers of the further course of CRС, since their appearance identifies patients with a high risk of mortality, and timely or preventive correction of the inflammatory response improves their survival. Conclusions. The results of the study show that the most informative markers of the level of inflammatory response after RFA or surgical resection are the levels of C-reactive protein, IL-6 and ferritin. Moderate inflammatory reaction is shown in the early stages after RFA and pronounced and longer-lasting reaction after surgical treatment. Prediction, assessment of the degree of inflammatory reaction and the feasibility of anti-inflammatory therapy in the early stages after intervention can be determined by the complex of immunological, haematological and biochemical markers studied by us.

Impact of perioperative steroid administration in patients undergoing elective liver resection: meta-analysis

BACKGROUND

Perioperative steroid administration may improve postoperative outcomes in major abdominal surgery by reducing the systemic inflammatory response. The aim of this systematic review was to evaluate the impact of perioperative steroid administration on outcomes after elective liver resection.

METHODS

PubMed, Cochrane Library, and Web of Science were systematically searched for randomized clinical trials (RCTs) comparing perioperative steroid administration with placebo, standard of care, or no steroids with respect to postoperative outcomes, particularly postoperative complications. Two independent reviewers critically appraised the studies and extracted data. Meta-analyses were performed using a random-effects model with ORs calculated for dichotomous outcomes and mean differences (MDs) for continuous outcomes.

RESULTS

Ten RCTs comprising 930 patients were included. Perioperative steroid administration significantly reduced the overall postoperative complication rate (OR 0.61, 95 per cent c.i. 0.43 to 0.87; P = 0.006; I2 = 26 per cent). No significant differences were shown for individual complications. Several postoperative laboratory parameters were positively affected, like total serum bilirubin (MD -0.46; 95 per cent c.i. -0.74 to -0.18; P = 0.001; I2 = 80 per cent), interleukin 6 (MD -48.99; 95 per cent c.i. -60.72 to -37.27; P < 0.001; I2 = 0 per cent) and C-reactive protein (MD -5.20; 95 per cent c.i. -7.62 to -2.77; P < 0.001; I2 = 71 per cent). There were no signs of an increase in potential steroid-induced adverse events, namely infectious complications, thromboembolic events, or bleeding.

CONCLUSIONS

Perioperative steroid administration significantly reduces the overall complication rate after elective liver resection without an increased risk of adverse effects.

Effect of rapid rehabilitation nursing on inflammation and liver function after laparoscopic radical resection of primary liver cancer

OBJECTIVE

To explore the effect of rapid rehabilitation nursing on inflammation and liver function in patients with primary liver cancer (PLC) after laparoscopic radical resection.

METHODS

A total of 124 PLC patients who underwent laparoscopic radical surgery in the Zhuji People's Hospital of Zhejiang Province from April 2019 to July 2021 were enrolled in this retrospective study. Among them, 65 patients who received rapid rehabilitation nursing were assigned into the observation group (OG), and the other 59 with routine nursing were considered to be the control group (CG). The pain before operation (T0), 3 days after operation (T1) and 7 days after operation (T2) was evaluated by visual analogue scale (VAS). The perioperative related indexes and nursing satisfaction were compared. The levels of liver function indexes alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) and inflammatory factors C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured before operation, 1 day and 7 days after operation. Finally, the incidence of postoperative complications was counted, the 6-month survival rate of both groups of patients was compared.

RESULTS

There was no obvious difference in VAS scores between the two groups at T0 (P>0.050), but the VAS scores at T1 and T2 in the OG were lower than those in the CG (P<0.001). There was no marked difference in the total operation time. Compared with the CG, the time to first exhaust, catheter indwelling and hospitalization in the OG were shorter (P<0.001) and the nursing satisfaction rate was higher (P<0.05). There was no obvious difference in ALT, AST and TBIL on the 1st day after operation (P>0.05); however, on the 7th day after operation, ALT and AST were lower while TBIL was higher in the OG (all P<0.05). There was no marked difference in CRP, IL-6 and TNF-α between the two groups on postoperative day 1 (P>0.05), but the levels were lower in the OG than those in the CG on postoperative day 7 (all P<0.05), and the total incidence of adverse reactions in the OG was lower (P<0.05). There was no statistical difference in the postoperative survival rate between both groups of patients (P>0.05). Age, number of lesions, tumor size, Child-Pugh grade, AST, TBIL, CRP, IL-6, TNF-α were associated with the survival rate of patients.

CONCLUSION

Rapid rehabilitation nursing can effectively reduce adverse reactions after laparoscopic radical resection of PLC. Thus, it has a high application value in future clinical treatment.

Assessment of the effect of perineural dexmedetomidine on oxidative stress during peritoneal dialysis catheter insertion: a randomized, controlled trial

Purpose

This study aimed to evaluate the effect of the addition of dexmedetomidine to ropivacaine on oxidative stress during transversus abdominis plane (TAP) and rectus sheath (RS) blockades for patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) catheter insertion.

Methods

Sixty patients with ESRD undergoing PD catheter insertion to receive left ultrasound-guided TAP and RS blockades were randomly divided into two groups: the dexmedetomidine plus ropivacaine group (25 mL of 0.3% ropivacaine + 1 μg/kg dexmedetomidine) and the ropivacaine group (25 mL of 0.3% ropivacaine). Primary outcomes were oxidative stress marker levels during the procedure.

Results

A total of 60 patients (30 patients in each group) were evaluated. Compared with the ropivacaine group, the dexmedetomidine plus ropivacaine group had significantly lower serum malondialdehyde levels (P < 0.05) and increased glutathione peroxidase (P < 0.01) and superoxide dismutase levels at 24 h after the procedure (P < 0.01).

Conclusion

The addition of 1 μg/kg of dexmedetomidine to ropivacaine for ultrasound-guided TAP and RS blockades could inhibit oxidative stress in patients with ESRD undergoing PD catheter insertion.

Trial registration This study was registered at www.chictr.org.cn on June 7, 2021 (ChiCTR2100047050).

Oxidative Stress Predicts Post-Surgery Complications in Gastrointestinal Cancer Patients

INTRODUCTION

An excessive perioperative inflammatory reaction can lead to more postoperative complications in patients treated for gastrointestinal cancers. It has been suggested that this inflammatory reaction leads to oxidative stress. The most important nonenzymatic antioxidants are serum free thiols. The purpose of this study was to evaluate whether high preoperative serum free thiol levels are associated with short-term clinical outcomes.

METHODS

Blood samples were drawn before, at the end of, and 1 and 2 days after surgery of a consecutive series of patients with gastrointestinal cancer. Serum free thiols were detected using a colorimetric detection method using Ellman's reagent. Short-term clinical outcomes were defined as 30-day complications (Clavien-Dindo ≥2) and length of hospital stay. Logistic regression was applied to examine the association between serum free thiol levels and short-term patient outcomes.

RESULTS

Eighty-one patients surgically treated for gastrointestinal cancer were included in the study. Median age was 68 (range 26-87) years, and 28% were female. Patients in the lowest tertile of preoperative serum free thiols had a threefold higher risk to develop postoperative complications (odds ratio [OR]: 3.4; 95% confidence interval [CI]:1.1-10.7) and a fourfold higher risk to have an increased length of stay in the hospital (OR 4.0; 95% CI 1.3-12.9) compared with patients in the highest tertile.

CONCLUSIONS

Patients with lower preoperative serum free thiol levels, indicating a decrease in extracellular antioxidant capacity and therefore an increase in systemic oxidative stress, are more likely to develop postoperative complications and show a longer in hospital stay than patients with higher serum free thiol levels.

Perioperative supplemental oxygen and oxidative stress in patients undergoing moderate- to high-risk major abdominal surgery - A subanalysis of randomized clinical trial

STUDY OBJECTIVE

Oxidative stress plays a pivotal role in the development and aggravation of cardiovascular diseases. The influence of intraoperative inspired oxygen concentrations on oxidative stress is still not entirely known. Therefore, we evaluated in this sub-study if supplemental oxygen affects the oxidation-reduction potential in patients at-risk for cardiovascular complications undergoing moderate- to high-risk major abdominal surgery.

DESIGN

Sub-study of a prospective parallel-arm double-blinded single-center superiority randomized trial.

SETTING

Operating room and postoperative recovery area.

INTERVENTION

Administration of 0.8 FiO₂ versus 0.3 FiO₂ throughout surgery and for the first two postoperative hours.

MEASUREMENTS

The primary outcome was the static oxidation-reduction potential (sORP) and the oxidation-reduction potential capacity (cORP) between both groups. The secondary outcome was the trend of sORP and cORP in the overall study population. We assessed sORP and cORP before induction of anesthesia, 2 h after induction of anesthesia, within 2 h after surgery and on the first and third postoperative day.

MAIN RESULTS

258 patients were analyzed. 128 patients were randomly assigned to the 80% oxygen group and 130 patients were randomly assigned to the 30% oxygen group. Postoperative sORP values did not differ significantly between the 80% and 30% oxygen group (effect estimate: -1.162 mV,95% CI: -2.584 to 0.260; p = 0.109). On average, we observed a change in sORP of 5.288 mV (95% CI:4.633 to 5.913, p < 0.001) per day. cORP values did not differ significantly between the 80% and 30% oxygen group (effect estimate: -0.015μC, (95%CI: -0.062 to 0.032; p = 0.524). On average, we observed a change in cORP values of -0.170μC (95%CI: -0.194 to -0.147, p < 0.001) per day.

CONCLUSION

In contrast to previous reports, we could not find any evidence of an association between intraoperative supplemental oxygen and perioperative oxidative stress assessed by sORP and cORP.

TRIAL REGISTRATION

clinicaltrials.gov: NCT03366857https://clinicaltrials.gov/ct2/show/NCT03366857?term=vienna&cond=oxygen&draw=2&rank=1.

Effect of hydrogen gas inhalation on patient QOL after hepatectomy: protocol for a randomized controlled trial

Introduction

Molecular hydrogen had been considered inactive in vivo but is an antioxidant that selectively reduces highly toxic reactive oxygen species (ROS). Animal studies have reported that hydrogen gas inhalation helped alleviate cerebral and cardiac ischemia-reperfusion injuries. In humans, hydrogen inhalation therapy is presently approved as a treatment under Advanced Medical Care B in Japan (jRCTs031180352: limited to adult patients who suffered out-of-hospital cardiac arrest and are in a continuous coma) and its effectiveness is being examined in a clinical trial. The Japanese government has introduced the “Advanced Medical Care System” to promote the development of drugs and devices under governmental regulations. Advanced Medical Care B is a system designed for unapproved or off-label drugs or medical technologies used in a clinical trial setting. Hepatectomy is generally performed with repeated hepatic blood-flow occlusion and then reperfusion (ischemia and reperfusion). No report, however, has been made on ROS inhibition by hydrogen inhalation therapy or its effectiveness in post-hepatectomy patients. Hydrogen gas inhalation in the early stages after hepatectomy is anticipated to inhibit liver dysfunction by inhibiting ROS.

Methods and analysis

This study is a randomized, controlled, double-blind superiority trial, which will be conducted as a “specified clinical trial” in accordance with the Clinical Trials Act in Japan. Trial registration was prospectively completed before the first participant was enrolled.

The subjects will be patients who will undergo hepatectomy and will be allocated randomly into group A with hydrogen gas inhalation or group B with air inhalation after hepatectomy. The study will examine if hydrogen gas inhalation improves QOL of post-hepatectomy patients. The primary endpoint is patient QOL (score of a 40-item quality of recovery questionnaire, QoR40) on postoperative day 3 and the secondary endpoints are QoR40s besides that on postoperative day 3, grade of postoperative complications (Clavien-Dindo score), level of pain (Numerical Rating Scale (NRS)), amount of dietary intake, liver function, inflammation level, 8-hydroxydeoxyguanosine (urinary 8-OHdG) level, and number of pedometer-assessed steps.

Ethics and dissemination

The study protocol has been approved by the Niigata University Central Review Board of Clinical Research. The findings of this study will be widely disseminated through peer-reviewed publications and conference presentations.

Trial registration

jRCTs 03220332. Registered on 21 January 2021

Real-time observation of microcirculatory leukocytes in patients undergoing major liver resection

Ischemia/reperfusion injury and inflammation are associated with microcirculatory dysfunction, endothelial injury and glycocalyx degradation. This study aimed to assess microcirculation in the sublingual, intestinal and the (remnant) liver in patients undergoing major liver resection, to define microcirculatory leukocyte activation and its association with glycocalyx degradation. In this prospective observational study, the microcirculation was assessed at the beginning of surgery (T0), end of surgery (T1) and 24 h after surgery (T2) using Incident Dark Field imaging. Changes in vessel density, blood flow and leukocyte behaviour were monitored, as well as clinical parameters. Syndecan-1 levels as a parameter of glycocalyx degradation were analysed. 19 patients were included. Sublingual microcirculation showed a significant increase in the number of rolling leukocytes between T0 and T1 (1.5 [0.7-1.8] vs. 3.7 [1.7-5.4] Ls/C-PCV/4 s respectively, p = 0.001), and remained high at T2 when compared to T0 (3.8 [3-8.5] Ls/C-PCV/4 s, p = 0.006). The microvascular flow decreased at T2 (2.4 ± 0.3 vs. baseline 2.8 ± 0.2, respectively, p < 0.01). Duration of vascular inflow occlusion was associated with significantly higher numbers of sublingual microcirculatory rolling leukocytes. Syndecan-1 increased from T0 to T1 (42 [25-56] vs. 107 [86-164] ng/mL, p < 0.001). The microcirculatory perfusion was characterized by low convection capacity and high number of rolling leukocytes. The ability to sublingually monitor the rolling behaviour of the microcirculatory leukocytes allows for early identification of patients at risk of increased inflammatory response following major liver resection.

The effect of mannitol on oxidation-reduction potential in patients undergoing deceased donor renal transplantation-A randomized controlled trial

BACKGROUND

Mannitol, an osmotic diuretic, is proposed to be an oxygen radical scavenger. Mannitol is often used in renal transplantation to attenuate oxidative stress and thus to protect renal graft function. We tested the hypothesis that mannitol reduces overall oxidative stress during deceased donor renal transplantation.

METHODS

We randomly assigned 34 patients undergoing deceased donor renal transplantation to receive a solution of mannitol or placebo shortly before graft reperfusion until the end of surgery. We evaluated oxidative stress by measuring the static oxidative-reduction potential (sORP) and the capacity of the oxidative-reduction potential (cORP). sORP and cORP were measured pre-operatively, before and within 10 minutes after graft reperfusion, and post-operatively.

RESULTS

Seventeen patients were enrolled in the mannitol group and 17 patients were enrolled in the placebo group. Mannitol had no significant effect on sORP (148.5 mV [136.2; 160.2]) as compared to placebo (143.6 mV [135.8; 163.2], P = .99). There was also no significant difference in cORP between the mannitol (0.22 µC [0.16; 0.36]) and the placebo group (0.22 µC [0.17; 0.38], P = .76).

CONCLUSION

Mannitol showed no systemic redox scavenging effects during deceased donor renal transplantation. To evaluate the direct effect of mannitol on the renal graft further studies are needed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02705573.

Systemic Inflammatory Response Syndrome After Surgery: Mechanisms and Protection

The immune system is an evolutionary hallmark of higher organisms that defends the host against invading pathogens and exogenous infections. This defense includes the recruitment of immune cells to the site of infection and the initiation of an inflammatory response to contain and eliminate pathogens. However, an inflammatory response may also be triggered by noninfectious stimuli such as major surgery, and, in case of an overshooting, still not comprehensively understood reaction, lead to tissue destruction and organ dysfunction. Unfortunately, in some cases, the immune system may not effectively distinguish between stimuli elicited by major surgery, which ideally should only require a modest inflammatory response, and those elicited by trauma or pathogenic infection. Surgical procedures thus represent a potential trigger for systemic inflammation that causes the secretion of proinflammatory cytokines, endothelial dysfunction, glycocalyx damage, activation of neutrophils, and ultimately tissue and multisystem organ destruction. In this review, we discuss and summarize currently available mechanistic knowledge on surgery-associated systemic inflammation, demarcation toward other inflammatory complications, and possible therapeutic options. These options depend on uncovering the underlying mechanisms and could include pharmacologic agents, remote ischemic preconditioning protocols, cytokine blockade or clearance, and optimization of surgical procedures, anesthetic regimens, and perioperative inflammatory diagnostic assessment. Currently, a large gap between basic science and clinically confirmed data exists due to a limited evidence base of translational studies. We thus summarize important steps toward the understanding of the precise time- and space-regulated processes in systemic perioperative inflammation.

Lipidomic signatures of post-hepatectomy liver failure using porcine hepatectomy models

Background

Clinical diagnosis of post-hepatectomy liver failure (PHLF) can only be made on or after the 5th postoperative day. Biomarker for early diagnosis is considered as a critical unmet need.

Methods

Twenty domestic female crossbreed (Yorkshire-landrace and duroc) pigs underwent sham operation (n=6), 70% (n=7) and 90% (n=7) partial hepatectomy (PH). A comprehensive lipidomic analysis was conducted using sera collected at pre-operation (PO), 14, 30, and 48 h after PH using nanoflow ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

Results

Of the 184 quantified lipids, 14 lipids showed significant differences between the two resection groups starting at 30 h after surgery. Four phosphatidylcholine (PC) plasmalogen species (P-16:0/16:0, P-18:0/18:2, P-18:0/20:4, and P-18:0/22:6) and PC 32:2 significantly increased in the 90% PH group while these returned to PO level after 30 h in the 70% PH group, presumably implying the failure markers. In contrast, eight triacylglycerol (TG) species (40:0, 42:1, 42:0, 44:1, 44:2, 46:1, 46:2, and 48:3) and sphingomyelin d18:1/20:0 showed an opposite trend, wherein they significantly decreased in the 90% PH group while these in the 70% PH group were abruptly increased until 30 h but returned to near PO levels at 48 h, implying the recovery markers. Same trends could also be observed in the level of whole lipid classes of PC plasmalogens and TGs, in addition to selected individual lipid species.

Conclusions

Characteristic lipidomic signatures of PHLF could be identified using large animal models. These candidates have a potential to serve as a tool for early diagnosis and may open new paths to the study to overcome PHLF.

No alteration of Cyp3A4 activity after major hepatectomy in the early postoperative period - A prospective before-after study

BACKGROUND

The impact of major liver resection (LR) on the detoxifying function of the remaining liver tissue as represented by CYP3A activity has yet to be assessed. Therefore, this study evaluates the changes in CYP3A activity between preoperative values and after liver resection.

MATERIAL AND METHODS

To determine CYP3A activity, midazolam (MDZ) was used as a marker substance, 3 μg were applied intravenously one day before surgery and on the 3rd day after surgery. Subsequently blood was withdrawn at 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3, 4 and 6 h post application of the study drug. Plasma MDZ and 1-OH-MDZ concentration was assessed using a LC-MS/MS method. Volumetric analysis of the resected liver was done by syngo.CT liver analysis software (Siemens Healthineers) using preoperative multidetector computed tomography.

RESULTS

N = 13 (8 male/5 female) patients were included in this study and received preoperative evaluation, 11 patients were studied also after liver resection. The mean age was 62 (±15.3) years with a mean BMI of 23.6 ± 4.8 kg/m². No patient suffered from acute liver dysfunction postoperatively. None of the pharmacokinetic parameters assessed were significantly altered by liver resection. CYP3A activity over time was not significantly reduced by major liver resection.

CONCLUSION

This study gives first time data on the impact of major liver resection on CYP3A activity. It was shown that MDZ clearance representing in vivo CYP3A activity is not altered by major liver resection. This suggests no dose adjustment of commonly applied drugs which are CYP3A substrates needs to be carried out.

Perioperative Oxidative Stress: The Unseen Enemy

Reactive oxygen species (ROS) are essential for cellular signaling and physiological function. An imbalance between ROS production and antioxidant protection results in a state of oxidative stress (OS), which is associated with perturbations in reduction/oxidation (redox) regulation, cellular dysfunction, organ failure, and disease. The pathophysiology of OS is closely interlinked with inflammation, mitochondrial dysfunction, and, in the case of surgery, ischemia/reperfusion injury (IRI). Perioperative OS is a complex response that involves patient, surgical, and anesthetic factors. The magnitude of tissue injury inflicted by the surgery affects the degree of OS, and both duration and nature of the anesthetic procedure applied can modify this. Moreover, the interindividual susceptibility to the impact of OS is likely to be highly variable and potentially linked to underlying comorbidities. The pathological link between OS and postoperative complications remains unclear, in part due to the complexities of measuring ROS- and OS-mediated damage. Exogenous antioxidant use and exercise have been shown to modulate OS and may have potential as countermeasures to improve postoperative recovery. A better understanding of the underlying mechanisms of OS, redox signaling, and regulation can provide an opportunity for patient-specific phenotyping and development of targeted interventions to reduce the disruption that surgery can cause to our physiology. Anesthesiologists are in a unique position to deliver countermeasures to OS and improve physiological resilience. To shy away from a process so fundamental to the welfare of these patients would be foolhardy and negligent, thus calling for an improved understanding of this complex facet of human biology.

Use of perioperative epidural analgesia among Medicare patients undergoing hepatic and pancreatic surgery

BACKGROUND

We sought to characterize epidural analgesia (EA) use among Medicare patients undergoing hepatopancreatic (HP) procedures, identify factors associated with EA use and asses perioperative outcomes.

METHODS

Patients undergoing HP surgery were identified using the Inpatient Standard Analytic Files. Logistic regression was utilized to identify factors associated with EA receipt, and assess associations of EA with in-hospital outcomes and Medicare expenditures.

RESULTS

Among 20,562 patients included in the study, 6.7% (n =1362) had EA. There was no difference in the odds of complications (OR 1.05, 95% CI 0.93-1.19) or blood transfusions (OR 0.90, 95% CI 0.79-1.03) with EA versus conventional analgesia (CA). The odds of prolonged LOS (OR 1.16, 95% CI 1.03-1.30) were higher with EA; the odds of in-hospital mortality were higher with conventional analgesia (OR 1.90, 95% CI 1.28-2.83). Medicare payments for liver surgery were comparable among EA ($19,500) versus conventional analgesia ($19,300, p = 0.85) and slightly higher for EA ($23,600) versus conventional analgesia ($22,000, p < 0.001) for pancreatic procedures.

CONCLUSION

EA utilization among Medicare patients undergoing HP was low. While EA was not associated with morbidity, it resulted in an average additional one day LOS and slightly higher expenditures in pancreatic surgery.

Effect of ω-3 polyunsaturated fatty acids on liver function and inflammatory reaction in patients undergoing hepatectomy: a systematic review and meta-analysis of randomized control trials

Several studies have investigated the relationship between ω-3 polyunsaturated fatty acids (PUFAs) administration and liver function and inflammatory reaction in patients undergoing liver resection, but the results remain conflicting and inconclusive. Areas covered: In this meta-analysis, a relevant database search was performed to retrieve all the randomized controlled trials (RCTs) exploring the effect of ω-3 PUFAs administration in patients undergoing hepatectomy until the end of April 2018. A random effect model was used to conduct this meta-analysis with RevMan 5.3.5 software. The quality of evidence for each postoperative outcome was assessed using the GRADEpro analysis. Expert opinion: 4 RCTs including 553 patients (277 with and 276 without ω-3 PUFAs) were identified. ω-3 PUFAs significantly reduced alanine aminotransferase [Mean difference (MD): -68.82, 95% confidence interval (CI): -108.55 to - 29.08; p = 0.0007]; aspartate aminotransferase (MD: -64.92, 95% CI: -112.87 to -16.98; p = 0.008), white blood cell count (MD: -1.22, 95% CI: -2.15 to -0.29; p = 0.01) and increased the level of pre-albumin on postoperative day 3 (MD: 10.42, 95% CI: 4.84 to 15.99; p = 0.0002). The results indicate that ω-3 PUFAs administration has a positive impact on the liver function and inflammatory reaction in patients undergoing liver resection.

Associations of Oxidative Stress and Postoperative Outcome in Liver Surgery with an Outlook to Future Potential Therapeutic Options

Several types of surgical procedures have shown to elicit an inflammatory stress response, leading to substantial cytokine production and formation of oxygen-based or nitrogen-based free radicals. Chronic liver diseases including cancers are almost always characterized by increased oxidative stress, in which hepatic surgery is likely to potentiate at least in the short term and hereby furthermore impair the hepatic redox state. During liver resection, intermittent inflow occlusion is commonly applied to prevent excessive blood loss but resulting ischemia and reperfusion of the liver have been linked to increased oxidative stress, leading to impairment of cell functions and subsequent cell death. In the field of liver transplantation, ischemia/reperfusion injury has extensively been investigated in the last decades and has recently been in the scientific focus again due to increased use of marginal donor organs and new machine perfusion concepts. Therefore, given the intriguing role of oxidative stress in the pathogenesis of numerous diseases and in the perioperative setting, the interest for a therapeutic antioxidative agent has been present for several years. This review is aimed at giving an introduction to oxidative stress in surgical procedures in general and then examines the role of oxidative stress in liver surgery in particular, discussing both transplantation and resection. Results from studies in the animal and human settings are included. Finally, potential therapeutic agents that might be beneficial in reducing the burden of oxidative stress in hepatic diseases and during surgery are presented. While there is compelling evidence from animal models and a limited number of clinical studies showing that oxidative stress plays a major role in both liver resection and transplantation and several recent studies have suggested a potential for antioxidative treatment in chronic liver disease (e.g., steatosis), the search for effective antioxidants in the field of liver surgery is still ongoing.