Stromal vapors for real-time molecular guidance of breast-conserving surgery

Achieving radical tumor resection while preserving disease-free tissue during breast-conserving surgery (BCS) remains a challenge. Here, mass spectrometry technologies were used to discriminate stromal tissues reported to be altered surrounding breast tumors, and build tissue classifiers ex vivo. Additionally, we employed the approach for in vivo and real-time classification of breast pathology based on electrosurgical vapors. Breast-resected samples were obtained from patients undergoing surgery at MUMC+. The specimens were subsequently sampled ex vivo to generate electrosurgical vapors analyzed by rapid evaporative ionization mass spectrometry (REIMS). Tissues were processed for histopathology to assign tissue components to the mass spectral profiles. We collected a total of 689 ex vivo REIMS profiles from 72 patients which were analyzed using multivariate statistical analysis (principal component analysis-linear discriminant analysis). These profiles were classified as adipose, stromal and tumor tissues with 92.3% accuracy with a leave-one patient-out cross-validation. Tissue recognition using this ex vivo-built REIMS classification model was subsequently tested in vivo on electrosurgical vapors. Stromal and adipose tissues were classified during one BCS. Complementary ex vivo analyses were performed by REIMS and by desorption electrospray ionization mass spectrometry (DESI-MS) to study the potential of breast stroma to guide BCS. Tumor border stroma (TBS) and remote tumor stroma (RTS) were classified by REIMS and DESI-MS with 86.4% and 87.8% accuracy, respectively. We demonstrate the potential of stromal molecular alterations surrounding breast tumors to guide BCS in real-time using REIMS analysis of electrosurgical vapors.

Intestinal function is impaired in patients with Chronic Obstructive Pulmonary Disease

BACKGROUND & AIMS

Gastrointestinal symptoms are prevalent extrapulmonary systemic manifestations of Chronic Obstructive Pulmonary Disease (COPD), but have been rarely studied. We dissected the perturbations in intestinal function in human patients with COPD using comprehensive metabolic and physiological approaches.

METHODS

In this observational study, small intestinal membrane integrity and active carrier-mediated glucose transport were quantified by sugar permeability test in 21 clinically stable patients with moderate to severe COPD (mean FEV₁, 41.2 (3.2) % of predicted) and 16 healthy control subjects. Protein digestion and absorption was analyzed using stable tracer kinetic methods. Plasma acetate, propionate, and butyrate concentrations were measured as markers of intestinal microbial metabolism.

RESULTS

Compared with healthy controls, non carrier-mediated permeability was higher (0.062 (95% CI [0.046, 0.078]) vs. 0.037 (95% CI [0.029, 0.045]), P = 0.009) and active glucose transport lower in COPD (31.4 (95% CI [23.4, 39.4])% vs. 48.0 (95% CI [37.8, 58.3])%, P = 0.010). Protein digestion and absorption was lower in COPD (0.647 (95% CI [0.588, 0.705]) vs. 0.823 (95% CI [0.737, 0.909]), P = 0007), and impairment greater in patients with dyspnea (P = 0.038), exacerbations in preceding year (P = 0.052), and reduced transcutaneous oxygen saturation (P = 0.051), and was associated with reduced physical activity score (P = 0.016) and lower quality of life (P = 0.0007). Plasma acetate concentration was reduced in COPD (41.54 (95% CI [35.17, 47.91]) vs. 80.44 (95% CI [54.59, 106.30]) μmol/L, P = 0.001) suggesting perturbed intestinal microbial metabolism.

CONCLUSIONS

We conclude that intestinal dysfunction is present in COPD, worsens with increasing disease severity, and is associated with reduced quality of life.

Preoperative Risk Assessment: A Poor Predictor of Outcome in Critically ill Elderly with Sepsis After Abdominal Surgery

Background

Postoperative outcome prediction in elderly is based on preoperative physical status but its predictive value is uncertain. The goal was to evaluate the value of risk assessment performed perioperatively in predicting outcome in case of admission to an intensive care unit (ICU).

Methods

A total of 108 postsurgical patients were retrospectively selected from a prospectively recorded database of 144 elderly septic patients (>70 years) admitted to the ICU department after elective or emergency abdominal surgery between 2012 and 2017. Perioperative risk assessment scores including Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality (P-POSSUM) and American Society of Anaesthesiologists Physical Status classification (ASA) were determined. Acute Physiology and Chronic Health Evaluation IV (APACHE IV) was obtained at ICU admission.

Results

In-hospital mortality was 48.9% in elderly requiring ICU admission after elective surgery (n = 45), compared to 49.2% after emergency surgery (n = 63). APACHE IV significantly predicted in-hospital mortality after complicated elective surgery [area under the curve 0.935 (p < 0.001)] where outpatient ASA physical status and P-POSSUM did not. In contrast, P-POSSUM and APACHE IV significantly predicted in-hospital mortality when based on current physical state in elderly requiring emergency surgery (AUC 0.769 (p = 0.002) and 0.736 (p = 0.006), respectively).

Conclusions

Perioperative risk assessment reflecting premorbid physical status of elderly loses its value when complications occur requiring unplanned ICU admission. Risks in elderly should be re-assessed based on current clinical condition prior to ICU admission, because outcome prediction is more reliable then.

International expert consensus on laparoscopic pancreaticoduodenectomy

IMPORTANCE

While laparoscopic pancreaticoduodenectomy (LPD) is being adopted with increasing enthusiasm worldwide, it is still challenging for both technical and anatomical reasons. Currently, there is no consensus on the technical standards for LPD.

OBJECTIVE

The aim of this consensus statement is to guide the continued safe progression and adoption of LPD.

EVIDENCE REVIEW

An international panel of experts was selected based on their clinical and scientific expertise in laparoscopic and open pancreaticoduodenectomy. Statements were produced upon reviewing the literature and assessed by the members of the expert panel. The literature search and its critical appraisal were limited to articles published in English during the period from 1994 to 2019. The Web of Science, Medline, and Cochrane Library and Clinical Trials databases were searched, The search strategy included, but was not limited to, the terms 'laparoscopic', 'pancreaticoduodenectomy, 'pancreatoduodenectomy', 'Whipple's operation', and 'minimally invasive surgery'. Reference lists from the included articles were manually checked for any additional studies, which were included when appropriate. Delphi method was used to establish expert consensus and the AGREE II-GRS Instrument was applied to assess the methodological quality and externally validate the final statements. The statements were further discussed during a one-day face-to-face meeting at the 1st Summit on Minimally Invasive Pancreatico-Biliary Surgery in Wuhan, China.

FINDINGS

Twenty-eight international experts from 8 countries constructed the expert panel. Sixteen statements were produced by the members of the expert panel. At least 80% of responders agreed with the majority (80%) of statements. Other than three randomized controlled trials published to date, most evidences were based on level 3 or 4 studies according to the AGREE II-GRS Instrument.

CONCLUSIONS AND RELEVANCE

The Wuhan international expert consensus meeting on LPD has produced a set of clinical practice statements for the safe development and progression of LPD. LPD is currently in its development and exploration stages, as defined by the international IDEAL framework for surgical innovation. More robust randomized controlled trial and registry study are essential to proceed with the assessment of LPD.

Low thoracic muscle radiation attenuation is associated with postoperative pneumonia following partial hepatectomy for colorectal metastasis

BACKGROUND

Low skeletal muscle radiation attenuation (SM-RA) is indicative of myosteatosis and diminished muscle function. It is predictive of poor outcome following oncological surgery in several cancer types. Postoperative pneumonia is a known risk factor for increased postoperative mortality. We hypothesized that low SM-RA of the respiratory muscles at the 4th thoracic-vertebra (T4) is associated with postoperative pneumonia following liver surgery.

METHODS

Postoperative pneumonia was identified using prospective infection control data. Computed tomography body composition analysis was performed at the L3-and T4 level to determine SM-RA. Body composition variables were corrected for confounders and related to postoperative pneumonia and admission time by multivariable logistic regression.

RESULTS

Body composition analysis of 180 patients was performed. Twenty-one patients developed postoperative pneumonia (11.6%). Multivariable analysis showed that low T4 SM-RA as well as low L3 SM-RA were significantly associated with postoperative pneumonia (OR 3.65, 95% CI 1.41-9.49, p < 0.01) and (OR 3.22, 95% CI 1.20-8.61, p = 0.02, respectively).

CONCLUSION

Low SM-RA at either the L3-or T4-level is associated with a higher risk of postoperative pneumonia following CLRM resection.

Muscle wasting associated co-morbidities, rather than sarcopenia are risk factors for hospital mortality in critical illness

BACKGROUND

Low skeletal muscle mass on intensive care unit admission is related to increased mortality. It is however unknown whether this association is influenced by co-morbidities that are associated with skeletal muscle loss. The aim of this study was to investigate whether sarcopenia is an independent risk factor for hospital mortality in critical illness in the presence of co-morbidities associated with muscle wasting.

METHODS

Data of 155 patients with abdominal sepsis were retrospectively analyzed. Skeletal muscle area was assessed using CT-scans at the level of vertebra L3. Demographic and clinical data were retrieved from electronic patient files. Sarcopenia was defined as a muscle area index below the 5th percentile of the general population. Uni- and multivariable analyses were performed to assess the association between sarcopenia and hospital mortality, correcting for age and comorbidities.

RESULTS

The prevalence of sarcopenia was higher in patients that did not survive until hospital discharge. However, it appeared that this relation was confounded by the presence of chronic renal insufficiency and cancer. These were independent risk factors for hospital mortality, whereas sarcopenia was not.

CONCLUSION

In critically ill patients with abdominal sepsis, muscle wasting associated co-morbidities rather than sarcopenia were risk factors for hospital mortality.

Targeting Pyruvate Kinase M2 and Lactate Dehydrogenase A Is an Effective Combination Strategy for the Treatment of Pancreatic Cancer

Reprogrammed glucose metabolism is one of the hallmarks of cancer, and increased expression of key glycolytic enzymes, such as pyruvate kinase M2 (PKM2) and lactate dehydrogenase A (LDHA), has been associated with poor prognosis in various malignancies. Targeting these enzymes could attenuate aerobic glycolysis and inhibit tumor proliferation. We investigated whether the PKM2 activator, TEPP-46, and the LDHA inhibitor, FX-11, can be combined to inhibit in vitro and in vivo tumor growth in preclinical models of pancreatic cancer. We assessed PKM2 and LDHA expression, enzyme activity, and cell proliferation rate after treatment with TEPP-46, FX-11, or a combination of both. Efficacy was validated in vivo by evaluating tumor growth, PK and LDHA activity in plasma and tumors, and PKM2, LDHA, and Ki-67 expression in tumor tissues following treatment. Dual therapy synergistically inhibited pancreatic cancer cell proliferation and significantly delayed tumor growth in vivo without apparent toxicity. Treatment with TEPP-46 and FX-11 resulted in increased PK and reduced LDHA enzyme activity in plasma and tumor tissues and decreased PKM2 and LDHA expression in tumors, which was reflected by a decrease in tumor volume and proliferation. The targeting of glycolytic enzymes such as PKM2 and LDHA represents a promising therapeutic approach for the treatment of pancreatic cancer.

Gallbladder Dyskinesia Is Associated With an Impaired Postprandial Fibroblast Growth Factor 19 Response in Critically Ill Patients

Critical illness is associated with a disturbed regulation of gastrointestinal hormones resulting in functional and metabolic anomalies. Fibroblast growth factor 19 (FGF19) is an ileum-derived metabolic hormone induced by bile salts upon gallbladder emptying after enteral nutrient stimulation. Our aim was to study the nutrient-stimulated FGF19 response in 24 patients admitted to the intensive care unit (ICU) compared with 12 healthy controls. All subjects received intraduodenal high-lipid nutrient infusion for 120 minutes. Blood was collected every 30 minutes until 1 hour after infusion, and gallbladder emptying was studied by ultrasound. Serum levels of bile salts and FGF19 were assessed. ICU patients had significantly higher fasting bile salt serum levels compared with controls, whereas FGF19 serum levels were similar. In both groups, nutrient infusion elicited substantial bile salt elevations (P < 0.001), peaking at 90 minutes, albeit with a significantly lower peak in the ICU patients (P = 0.029). In controls, FGF19 was significantly elevated relative to baseline from 120 minutes onward (P < 0.001). In ICU patients, the FGF19 response was blunted, as reflected by significantly lower FGF19 elevations at 120, 150, and 180 minutes (P < 0.05) and significantly lower area under the curve (AUC) values compared with controls (P < 0.001). Gallbladder dysmotility was associated with the impaired FGF19 response in critical illness. The gallbladder ejection fraction correlated positively with FGF19 AUC values (ρ = +0.34, P = 0.045). In 10 of 24 ICU patients, gallbladder emptying was disturbed. These patients had significantly lower FGF19 AUC values (P < 0.001). Gallbladder emptying and the FGF19 response were respectively disturbed or absent in patients receiving norepinephrine. Conclusion: The nutrient-stimulated FGF19 response is impaired in ICU patients, which is mechanistically linked to gallbladder dysmotility in critical illness. This may contribute to disturbed liver metabolism in these patients and has potential as a nutritional biomarker.

Impairments in Protein Digestion and Absorption Attenuate the Anabolic Response to Feeding in Patients with Congestive Heart Failure (FS09-03-19)

Objectives

Gastrointestinal symptoms are prevalent extracardiac systemic manifestations of Congestive Heart Failure (CHF). We developed a comprehensive panel of methods to unravel gut dysfunction in CHF and its impact on the anabolic response to feeding.

Methods

We recruited 14 clinically stable CHF patients (ejection fraction: 33.9 ± 2.1, NYHA class: 2.3 ± 0.2) and 17 healthy controls matched for age and gender. Stable tracers of L-phenylalanine (PHE)-[ring-2H5] and L-tyrosine (TYR)-[13C9,15 N] were administered intravenously for 5 hours via primed constant and continuous infusion. After 2 hours, participants ingested a complete high protein meal containing L-PHE-[1–13C] and spirulina-[U-15 N]. We sampled blood throughout the study to analyze enrichments by LC-MS/MS. We calculated the anabolic response to feeding before and after correction for changes in protein digestion and absorption, assessed by spirulina degradation ratio (L-PHE-[15 N]/[1–13C]). Moreover, we measured small intestinal membrane integrity and active carrier-mediated glucose transport by urinary recovery of the orally ingested inert sugars lactulose, rhamnose, and 3-O-methyl-glucose. Disease severity was assessed by medical chart and history. Statistical analysis was performed by unpaired t-tests. Data are expressed as mean ± SEM.

Results

In CHF patients, protein digestion and absorption were reduced (0.66 ± 0.04 vs. 0.82 ± 0.04, P < 0.01), which further attenuated the anabolic response to feeding (28.3 ± 3.8 vs. 54.0 ±5.5 μmol/kg FFM/meal, P < 0.001). Disturbances in protein digestion and absorption as well as anabolic response in CHF were independent of disease severity. Small intestinal permeability and active carrier-mediated glucose transport did not differ between the groups indicating a preserved enterocyte function in CHF patients.

Conclusions

We hypothesize that enhancing protein digestion and absorption in patients with CHF can improve the availability of nutrients and protein anabolism.

Funding Sources

National Institutes of Health

Tumour-specific and organ-specific protein synthesis rates in patients with pancreatic cancer

BACKGROUND

Living tissues maintain a fine balance between protein synthesis and protein breakdown rates. Animal studies indicate that protein synthesis rates are higher in organs when compared with skeletal muscle tissue. As such, organ and tumour protein synthesis could have major effects on whole-body protein metabolism in wasting disorders such as cancer cachexia. We aimed to assess protein synthesis rates in pancreatic tumour tissue and healthy pancreas, liver, and skeletal muscle tissue in vivo in humans.

METHODS

In eight patients with pancreatic cancer undergoing pancreaticoduodenectomy, primed continuous infusions with L-[ring-¹³ C₆ ]phenylalanine and L-[3,5-² H₂ ]tyrosine were started prior to surgery and continued throughout the surgical procedures. During surgery, plasma samples and biopsies from the pancreas, pancreatic tumour, liver, and vastus lateralis muscle were taken. Post-absorptive fractional protein synthesis rates were determined by measuring incorporation of labelled L-[ring-¹³ C₆ ]phenylalanine in tissue protein using the weighed plasma L-[ring-¹³ C₆ ]phenylalanine enrichments as the precursor pool.

RESULTS

Five male patients and three female patients with a mean age of 67 ± 2 years were included into this study. Plasma L-[ring-¹³ C₆ ]phenylalanine enrichments (6-9 mole per cent excess) did not change during surgery (P = 0.60). Pancreatic tumour protein synthesis rates were 2.6-fold lower than surrounding pancreatic tissue protein synthesis rates (0.268 ± 0.053 vs. 0.694 ± 0.228%/h, respectively; P = 0.028) and 1.7-fold lower than liver protein synthesis rates (0.268 ± 0.053 vs. 0.448 ± 0.043%/h, respectively; P = 0.046). Among healthy organ samples, protein synthesis rates were 20-fold and 13-fold higher in pancreas and liver, respectively, compared with skeletal muscle tissue (0.694 ± 0.228 and 0.448 ± 0.043 vs. 0.035 ± 0.005%/h, respectively; P < 0.05).

CONCLUSIONS

Liver and pancreas tissue protein synthesis rates are higher when compared with pancreatic tumour and skeletal muscle tissue protein synthesis rates and can, therefore, strongly impact whole-body protein metabolism in vivo in humans.

Low circulating concentrations of citrulline and FGF19 predict chronic cholestasis and poor survival in adult patients with chronic intestinal failure: development of a Model for End-Stage Intestinal Failure (MESIF risk score)

BACKGROUND

Patients with chronic intestinal failure (CIF) often develop cholestatic liver injury, which may lead to liver failure and need for organ transplantation.

OBJECTIVES

The aim of this study was to investigate whether citrulline (CIT) and the enterokine fibroblast growth factor 19 (FGF19) are associated with chronic cholestasis and survival in adult CIF patients, and to develop a risk score to predict their survival.

METHODS

We studied 135 adult CIF patients on intravenous supplementation (>3 mo). Associations of plasma CIT and FGF19 with chronic cholestasis and survival were estimated by logistic and Cox regression models. A predictive risk score was developed and validated internally.

RESULTS

Patients with chronic cholestasis (17%) had a reduced 5-y survival rate compared with patients without chronic cholestasis (38% and 62%, respectively). In multivariable analysis, low FGF19, low CIT, and female sex were associated with chronic cholestasis. Patients with low rather than high CIT or FGF19 also had reduced 5-y survival rates (29% compared with 69%; 54% compared with 66%, respectively). Risk factors identified in multivariable analysis of survival were low FGF19 (HR: 3.4), low CIT (HR: 3.3), and number of intravenous infusions per week (HR: 1.4). These 3 predictors were incorporated in a risk model of survival termed Model for End-Stage Intestinal Failure (MESIF) (C-statistic 0.78). The 5-y survival rates for patients with MESIF scores of 0 to <20 (n = 47), 20-40 (n = 75), and >40 (n = 13) were 80%, 58%, and 14%, respectively.

CONCLUSIONS

CIT and FGF19 predict chronic cholestasis and survival in this cohort of adult CIF patients, and the derived MESIF score is associated with their survival. Pending external validation, the MESIF score may help to identify patients for closer clinical monitoring or earlier referral to intestinal transplantation centers.

Surgery for cholangiocarcinoma

Surgical resection is the only potentially curative treatment for patients with cholangiocarcinoma. For both perihilar cholangiocarcinoma (pCCA) and intrahepatic cholangiocarcinoma (iCCA), 5-year overall survival of about 30% has been reported in large series. This review addresses several challenges in surgical management of cholangiocarcinoma. The first challenge is diagnosis: a biopsy is typically avoided because of the risk of seeding metastases and the low yield of a brush of the bile duct. However, about 15% of patients with suspected pCCA are found to have a benign diagnosis after resection. The second challenge is staging; even with the best preoperative imaging, a substantial percentage of patients has occult metastatic disease detected at staging laparoscopy or early recurrence after resection. The third challenge is an adequate volume and function of the future liver remnant, which may require preoperative biliary drainage and portal vein embolization. The fourth challenge is a complete resection: a positive bile duct margin is not uncommon because the microscopic biliary extent of disease may be more extensive than perceived on imaging. The fifth challenge is the high post-operative mortality that has decreased in very high volume Asian centres, but remains about 10% in many Western referral centres. The sixth challenge is that even after a complete resection most patients develop recurrent disease. Recent randomized controlled trials found conflicting results regarding the benefit of adjuvant chemotherapy. The final challenge is to determine which patients with cholangiocarcinoma should undergo liver transplantation rather than resection.

Host phenotype is associated with reduced survival independent of tumour biology in patients with colorectal liver metastases

BACKGROUND

Most prognostic scoring systems for colorectal liver metastases (CRLMs) account for factors related to tumour biology. Little is known about the effects of the host phenotype to the tumour. Our objective was to delineate the relationship of systemic inflammation and body composition features [i.e. low skeletal muscle mass (sarcopenia) and low visceral adipose tissue (VAT)], two well-described host phenotypes in cancer.

METHODS

Clinical data and pre-operative blood samples were collected from 99 patients who underwent resection of CRLM. Pre-operative computed tomography scans were available for 97 patients; body composition was analysed at the L3 level, stratified for sex and age. Clinicopathological variables, serum C-reactive protein (CRP), and various body composition variables were evaluated. Overall survival was evaluated as a function of these same variables in multivariate Cox regression analysis.

RESULTS

Skeletal muscle was significantly correlated with VAT (r = 0.46, P < 0.001). Of patients with sarcopenia, 35 (65%) also had low VAT. C-reactive protein was elevated (≥5 mg/mL) in 42 patients (43.3%). Elevated CRP was more common in patients with sarcopenia (73.8% vs. 51.1%, P = 0.029). The most significant prognostic factors were the coincidence of elevated CRP and adverse body composition features (sarcopenia and/or low VAT; hazard ratio 4.3, 95% confidence interval 1.5-13.0, P = 0.008), as well as Fong clinical prognostic score (hazard ratio 2.9, 95% confidence interval 1.5-5.5, P = 0.002).

CONCLUSIONS

Body composition in patients with CRLM is not directly linked to the presence of systemic inflammation. However, when systemic inflammation coincides with sarcopenia and/or low VAT, prognosis is adversely affected, independent of the Fong clinical prognostic score.

Impaired brain glymphatic flow in experimental hepatic encephalopathy

BACKGROUND & AIMS

Neuronal function is exquisitely sensitive to alterations in the extracellular environment. In patients with hepatic encephalopathy (HE), accumulation of metabolic waste products and noxious substances in the interstitial fluid of the brain is thought to result from liver disease and may contribute to neuronal dysfunction and cognitive impairment. This study was designed to test the hypothesis that the accumulation of these substances, such as bile acids, may result from reduced clearance from the brain.

METHODS

In a rat model of chronic liver disease with minimal HE (the bile duct ligation [BDL] model), we used emerging dynamic contrast-enhanced MRI and mass-spectroscopy techniques to assess the efficacy of the glymphatic system, which facilitates clearance of solutes from the brain. Immunofluorescence of aquaporin-4 (AQP4) and behavioural experiments were also performed.

RESULTS

We identified discrete brain regions (olfactory bulb, prefrontal cortex and hippocampus) of altered glymphatic clearance in BDL rats, which aligned with cognitive/behavioural deficits. Reduced AQP4 expression was observed in the olfactory bulb and prefrontal cortex in HE, which could contribute to the pathophysiological mechanisms underlying the impairment in glymphatic function in BDL rats.

CONCLUSIONS

This study provides the first experimental evidence of impaired glymphatic flow in HE, potentially mediated by decreased AQP4 expression in the affected regions.

LAY SUMMARY

The 'glymphatic system' is a newly discovered brain-wide pathway that facilitates clearance of various substances that accumulate in the brain due to its activity. This study evaluated whether the function of this system is altered in a model of brain dysfunction that occurs in cirrhosis. For the first time, we identified that the clearance of substances from the brain in cirrhosis is reduced because this clearance system is defective. This study proposes a new mechanism of brain dysfunction in patients with cirrhosis and provides new targets for therapy.

Interactions between bile salts, gut microbiota, and hepatic innate immunity

Bile salts are the water-soluble end products of hepatic cholesterol catabolism that are released into the duodenum and solubilize lipids due to their amphipathic structure. Bile salts also act as endogenous ligands for dedicated nuclear receptors that exert a plethora of biological processes, mostly related to metabolism. Bile salts are actively reclaimed in the distal part of the small intestine, released into the portal system, and subsequently extracted by the liver. This enterohepatic cycle is critically dependent on dedicated bile salt transporters. In the intestinal lumen, bile salts exert direct antimicrobial activity based on their detergent property and shape the gut microbiota. Bile salt metabolism by gut microbiota serves as a mechanism to counteract this toxicity and generates bile salt species that are distinct from those of the host. Innate immune cells of the liver play an important role in the early recognition and effector response to invading microbes. Bile salts signal primarily via the membrane receptor TGR5 and the intracellular farnesoid-x receptor, both present in innate immune cells. In this review, the interactions between bile salts, gut microbiota, and hepatic innate immunity are discussed.

Cross-Species Molecular Imaging of Bile Salts and Lipids in Liver: Identification of Molecular Structural Markers in Health and Disease

The liver is the primary organ involved in handling of bile salts, a class of amphipathic molecules with signaling activities as well as desired and detrimental detergent actions. To allow in-depth investigation of functions of bile salts in healthy and diseased liver, the spatial distribution of bile salt species within the liver needs to be studied. Therefore, the aim of our study was to determine hepatic bile salt distribution and identify specific lipid markers that define the structural elements of the liver. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) was used to monitor the spatial distribution of bile salts and lipids in liver sections of rat, dog, and patients with unaffected and cholestatic parenchyma. MALDI-MSI in negative ion mode showed the local presence of a variety of bile salts, predominantly taurine-conjugates, as localized patches of varying sizes (representing the bile ducts) throughout the liver tissue. Specific molecular markers were identified for the connective tissue (phosphatidic acids, e.g., [PA (18:0_18:1)–H]⁻), the liver parenchyma (phosphatidylinositols, e.g., [PI (18:0_20:4)-H]⁻), and the bile ducts (hydroxylated-sulfatides, e.g., [ST–OH (18:1_24:0)-H]⁻). One of these sulfatides (at m/z 906.6339) was found to be uniquely localized in a thin lining on the inside of the bile duct, colocalized with cytokeratins, and encased luminal bile salts. A similar distribution of the aforementioned sulfatide was observed, albeit in constricted ductular structures, in the liver of a patient with a mild clinical phenotype of primary sclerosing cholangitis (PSC). In contrast, sulfatides were virtually absent in the liver of patients with PSC and a severe clinical phenotype, with (atypical) cholanoids (e.g., the bile alcohol 5-cyprinolsulfate) abundant in the extra-ductular space and glyco(cheno)deoxycholic acid-3-sulfate localized to fibrotic connective tissue. The latter two molecular species were able to discriminate between healthy liver tissue (n = 3) and tissue from PSC patients with a severe clinical phenotype (n = 3). In conclusion, the distinct structural elements of the mammalian liver are characterized by specific classes of lipids. We propose that (hydroxylated-)sulfatides are specific molecular markers of the bile duct.

The prebiotic inulin improves substrate metabolism and promotes short-chain fatty acid production in overweight to obese men

BACKGROUND AND AIMS

Human gut microbiota play an important role in maintaining human health. Dietary fibers, i.e. prebiotics, are fermented by human gut microbiota into the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate. SCFAs promote fat oxidation and improve metabolic health. Therefore, the prebiotic inulin might be an effective dietary strategy to improve human metabolism. We aimed to investigate the acute metabolic effects of ingesting inulin compared with digestible carbohydrates and to trace inulin-derived SCFAs using stable isotope tracer methodology.

METHODS

In a double-blind, randomized, placebo-controlled crossover design, 14 healthy, overweight to obese men consumed a high-fat milkshake containing A) 24 g inulin of which 0.5 g was U-¹³C-inulin (INU) or B) 24 g maltodextrin placebo (PLA), with a wash-out period of at least five days. Fat oxidation was measured via an open-circuit ventilated hood and blood samples were collected up to 7 h after ingestion. Plasma, breath, and fecal samples were collected, and appetite and satiety scores were assessed.

RESULTS

Fat oxidation increased in the early postprandial phase (0-3 h), and both plasma glucose and insulin were lower after INU ingestion compared with PLA (all P < 0.05). Plasma free fatty acids were higher in the early, and lower in the late postprandial period after INU ingestion. Inulin was fermented into SCFAs as indicated by higher plasma acetate concentrations after INU compared with PLA (P < 0.05). In addition, we found continuous increases in plasma ¹³C-SCFA enrichments (P < 0.05 from t = 120 onwards) and breath ¹³CO₂ enrichments after INU intake. There were no effects on plasma triglycerides, free glycerol, satiety hormones GLP-1 and PYY, and appetite and satiety scores.

CONCLUSIONS

Ingestion of the prebiotic inulin improves fat oxidation and promotes SCFA production in overweight to obese men. Overall, replacing digestible carbohydrates with the fermentable inulin may favor human substrate metabolism.

CLINICAL TRIAL REGISTRY

The trial was registered at clinicaltrials.gov under number NCT02009670.

A New Scoring System to Predict Blood Stream Infections in Patients with Complicated Intra-Abdominal Infections: Experience from a Tertiary Referral Hospital in China

BACKGROUND

This purpose of this study was to investigate the effects of blood stream infections (BSIs) on the prognosis of patients with complicated intra-abdominal infections (IAIs) and to make predictions based on patients' characteristics on admission.

PATIENTS AND METHODS

One hundred eighty-seven patients with complicated IAI in 2014 and 2015 were included in our retrospective analysis, except for those diagnosed with central line-associated blood stream infections (CLABSIs). Patients with BSIs were compared with patients without BSIs. Multivariable logistic regression was applied to identify factors associated with BSIs and also the subtypes of BSIs. The predictive score systems were established further.

RESULTS

Seventy-four patients (39.6%) with complicated IAIs developed BSIs after admission. Four factors evaluated on admission were associated independently with BSIs including alanine aminotransferase (ALT) ≥66 U/L (two scores), insensitivity to initial empirical antibiotic agents (IIEA; three scores), Sepsis-Related Organ Failure Assessment (SOFA) score of two or more (three scores), and generalized peritonitis (four scores). A total score of five or more was regarded as the critical value in the combined test to predict BSIs, with a sensitivity of 0.78 and a specificity of 0.73. Blood stream infections were further divided as secondary BSIs and non-secondary BSIs. The risk factors of secondary BSIs included IIEA (three scores), SOFA score of two or more (five scores), and generalized peritonitis (eight scores), where a total score of nine or more was regarded as the critical value in the combined test, with a sensitivity of 0.68 and a specificity of 0.87, whereas the risk factors of non-secondary BSIs included IIEA (three scores), SOFA score of two or more (three scores) and procalcitonin (PCT) ≥0.43 mcg/L (three scores), where a total score of six or more was regarded as the critical value in the combined test, with a sensitivity of 0.75 and a specificity of 0.70. Moreover, BSIs were linked with the worse clinical outcomes in organ functions, hospitalization costs, and mortality.

CONCLUSIONS

Our new scoring methods may have potential advantages on the early prediction and recognition of BSIs in patients with complicated IAIs.

Endoscopic versus percutaneous biliary drainage in patients with resectable perihilar cholangiocarcinoma: a multicentre, randomised controlled trial

BACKGROUND

In patients with resectable perihilar cholangiocarcinoma, biliary drainage is recommended to treat obstructive jaundice and optimise the clinical condition before liver resection. Little evidence exists on the preferred initial method of biliary drainage. We therefore investigated the incidence of severe drainage-related complications of endoscopic biliary drainage or percutaneous transhepatic biliary drainage in patients with potentially resectable perihilar cholangiocarcinoma.

METHODS

We did a multicentre, randomised controlled trial at four academic centres in the Netherlands. Patients who were aged at least 18 years with potentially resectable perihilar cholangiocarcinoma requiring major liver resection, and biliary obstruction of the future liver remnant (defined as a bilirubin concentration of >50 μmol/L [2·9 mg/dL]), were randomly assigned (1:1) to receive endoscopic biliary drainage or percutaneous transhepatic biliary drainage through the use of computer-generated allocation. Randomisation, done by the trial coordinator, was stratified for previous (attempted) biliary drainage, the extent of bile duct involvement, and enrolling centre. Patients were enrolled by clinicians of the participating centres. The primary outcome was the number of severe complications between randomisation and surgery in the intention-to-treat population. The trial was registered at the Netherlands National Trial Register, number NTR4243.

FINDINGS

From Sept 26, 2013, to April 29, 2016, 261 patients were screened for participation, and 54 eligible patients were randomly assigned to endoscopic biliary drainage (n=27) or percutaneous transhepatic biliary drainage (n=27). The study was prematurely closed because of higher mortality in the percutaneous transhepatic biliary drainage group (11 [41%] of 27 patients) than in the endoscopic biliary drainage group (three [11%] of 27 patients; relative risk 3·67, 95% CI 1·15-11·69; p=0·03). Three of the 11 deaths among patients in the percutaneous transhepatic biliary drainage group occurred before surgery. The proportion of patients with severe preoperative drainage-related complications was similar between the groups (17 [63%] patients in the percutaneous transhepatic biliary drainage group vs 18 [67%] in the endoscopic biliary drainage group; relative risk 0·94, 95% CI 0·64-1·40). 16 (59%) patients in the percutaneous transhepatic biliary drainage group and ten (37%) patients in the endoscopic biliary drainage group developed preoperative cholangitis (p=0·1). 15 (56%) patients required additional percutaneous transhepatic biliary drainage after endoscopic biliary drainage, whereas only one (4%) patient required endoscopic biliary drainage after percutaneous transhepatic biliary drainage.

INTERPRETATION

The study was prematurely stopped because of higher all-cause mortality in the percutaneous transhepatic biliary drainage group. Post-drainage complications were similar between groups, but the data should be interpreted with caution because of the small sample size. The results call for further prospective studies and reconsideration of indications and strategy towards biliary drainage in this complex disease.

FUNDING

Dutch Cancer Foundation.

A novel human cell culture model to study visceral smooth muscle phenotypic modulation in health and disease

Adaptation of the smooth muscle cell (SMC) phenotype is essential for homeostasis and is often involved in pathologies of visceral organs (e.g., uterus, bladder, gastrointestinal tract). In vitro studies of the behavior of visceral SMCs under (patho)-physiological conditions are hampered by a spontaneous, uncontrolled phenotypic modulation of visceral SMCs under regular tissue culture conditions. We aimed to develop a new visceral SMC culture model that allows controlled phenotypic modulation. Human uterine SMCs [ULTR and telomerase-immortalized human myometrial cells (hTERT-HM)] were grown to confluency and kept for up to 6 days on regular tissue culture surfaces or basement membrane (BM) matrix-coated surfaces in the presence of 0-10% serum. mRNA and protein expression and localization of SMC-specific phenotype markers and their transcriptional regulators were investigated by quantitative PCR, Western blotting, and immunofluorescence. Maintaining visceral SMCs confluent for 6 days increased α-smooth muscle actin (1.9-fold) and smooth muscle protein 22-α (3.1-fold), whereas smooth muscle myosin heavy chain was only slightly upregulated (1.3-fold). Culturing on a BM matrix-coated surface further increased these proteins and also markedly promoted mRNA expression of γ-smooth muscle actin (15.0-fold), smoothelin (3.5-fold), h-caldesmon (5.2-fold), serum response factor (7.6-fold), and myocardin (8.1-fold). Whereas additional serum deprivation only minimally affected contractile markers, platelet-derived growth factor-BB and transforming growth factor β1 consistently reduced versus increased their expression. In conclusion, we present a simple and reproducible visceral SMC culture system that allows controlled phenotypic modulation toward both the synthetic and the contractile phenotype. This may greatly facilitate the identification of factors that drive visceral SMC phenotypic changes in health and disease.

Spatial Systems Lipidomics Reveals Nonalcoholic Fatty Liver Disease Heterogeneity

Hepatocellular lipid accumulation characterizes nonalcoholic fatty liver disease (NAFLD). However, the types of lipids associated with disease progression are debated, as is the impact of their localization. Traditional lipidomics analysis using liver homogenates or plasma dilutes and averages lipid concentrations, and does not provide spatial information about lipid distribution. We aimed to characterize the distribution of specific lipid species related to NAFLD severity by performing label-free molecular analysis by mass spectrometry imaging (MSI). Fresh frozen liver biopsies from obese subjects undergoing bariatric surgery (n = 23) with various degrees of NAFLD were cryosectioned and analyzed by matrix-assisted laser desorption/ionization (MALDI)-MSI. Molecular identification was verified by tandem MS. Tissue sections were histopathologically stained, annotated according to the Kleiner classification, and coregistered with the MSI data set. Lipid pathway analysis was performed and linked to local proteome networks. Spatially resolved lipid profiles showed pronounced differences between nonsteatotic and steatotic tissues. Lipid identification and network analyses revealed phosphatidylinositols and arachidonic acid metabolism in nonsteatotic regions, whereas low–density lipoprotein (LDL) and very low–density lipoprotein (VLDL) metabolism was associated with steatotic tissue. Supervised and unsupervised discriminant analysis using lipid based classifiers outperformed simulated analysis of liver tissue homogenates in predicting steatosis severity. We conclude that lipid composition of steatotic and nonsteatotic tissue is highly distinct, implying that spatial context is important for understanding the mechanisms of lipid accumulation in NAFLD. MSI combined with principal component–linear discriminant analysis linking lipid and protein pathways represents a novel tool enabling detailed, comprehensive studies of the heterogeneity of NAFLD.

Exploration of the platelet proteome in patients with early-stage cancer

Platelets play an important role in tumor growth and, at the same time, platelet characteristics are affected by cancer presence. Therefore, we investigated whether the platelet proteome harbors differentially expressed proteins associated with early-stage cancer. For this proof-of-concept study, patients with early-stage lung (n = 8) or head of pancreas cancer (n = 4) were included, as were healthy sex- and age-matched controls for both subgroups. Blood samples were collected from controls and from patients before surgery. Furthermore, from six of the patients, a second sample was collected two months after surgery. NanoLC-MS/MS-based proteomics of gel-fractionated platelet proteins was used for comparative spectral count analyses of patients to controls and before to after surgery samples. The total platelet proteome dataset included 4384 unique proteins of which 85 were significantly (criteria Fc > 1.5 and p < 0.05) changed in early-stage cancer compared to controls. In addition, the levels of 81 platelet proteins normalized after tumor resection. When filtering for the most discriminatory proteins, we identified seven promising platelet proteins associated with early-stage cancer. In conclusion, this pioneering study on the platelet proteome in cancer patients clearly identifies platelets as a new source of candidate protein biomarkers of early-stage cancer.

BIOLOGICAL SIGNIFICANCE

Currently, most blood-based diagnostics/biomarker research is performed in serum or plasma, while the content of blood cells is usually neglected. It is known that especially blood platelets, which are the main circulating pool of many bioactive proteins, such as growth factors, chemokines, and cytokines, are a potentially rich source of biomarkers. The current study is the first to measure the effect of early-stage cancer on the platelet proteome of patients. Our study demonstrates that the platelet proteome of patients with early-stage lung or head of pancreas cancer differs considerably compared to that of healthy individuals of matched sex and age. In addition, the platelet proteome of cancer patients normalized after surgical resection of the tumor. Exploiting platelet proteome differences linked to both tumor presence and disease status, we were able to demonstrate that the platelet proteome can be mined for potential biomarkers of cancer.

Impact of chemotherapy-associated liver injury on tumour regression grade and survival in patients with colorectal liver metastases

BACKGROUND

An inverse relation between chemotherapy-associated liver injury (CALI) and tumour response to chemotherapy has been reported. The aim was to validate these findings, and further investigate the impact of CALI on survival in patients who underwent partial hepatectomy for colorectal liver metastases (CRLM).

METHODS

Patients who received neoadjuvant chemotherapy and underwent partial hepatectomy for CRLM between 2008 and 2014 were included. Liver and tumour specimens were histologically examined for CALI (steatosis, steatohepatitis, sinusoidal dilatation [SD], nodular regeneration) and tumour regression grade (TRG). TRG 1-2 was defined as complete tumour response.

RESULTS

166 consecutive patients were included with a median survival of 30 and 44 months for recurrence-free and overall survival, respectively. Grade 2-3 SD was found in 44 (27%) and TRG 1-2 was observed in 33 (20%) patients. Of studied CALI, only grade 2-3 SD was associated with increased TRG 3-5 (odds ratio 3.99, 95% CI 1.17-13.65, p = 0.027). CALI was not significantly related to survival. TRG 1-2 was associated with prolonged recurrence-free (hazard ratio 0.47, 95% CI 0.25-0.89, p = 0.020) and overall survival (hazard ratio 0.35, 95% CI 0.18-0.68, p = 0.002).

CONCLUSION

CALI was not directly related to survival. CALI was, however, associated with diminished complete tumour response, and diminished complete tumour response, in turn, was associated with decreased survival.

Distinct fecal and oral microbiota composition in human type 1 diabetes, an observational study

OBJECTIVE

Environmental factors driving the development of type 1 diabetes (T1D) are still largely unknown. Both animal and human studies have shown an association between altered fecal microbiota composition, impaired production of short-chain fatty acids (SCFA) and T1D onset. However, observational evidence on SCFA and fecal and oral microbiota in adults with longstanding T1D vs healthy controls (HC) is lacking.

RESEARCH DESIGN AND METHODS

We included 53 T1D patients without complications or medication and 50 HC matched for age, sex and BMI. Oral and fecal microbiota, fecal and plasma SCFA levels, markers of intestinal inflammation (fecal IgA and calprotectin) and markers of low-grade systemic inflammation were measured.

RESULTS

Oral microbiota were markedly different in T1D (eg abundance of Streptococci) compared to HC. Fecal analysis showed decreased butyrate producing species in T1D and less butyryl-CoA transferase genes. Also, plasma levels of acetate and propionate were lower in T1D, with similar fecal SCFA. Finally, fecal strains Christensenella and Subdoligranulum correlated with glycemic control, inflammatory parameters and SCFA.

CONCLUSIONS

We conclude that T1D patients harbor a different amount of intestinal SCFA (butyrate) producers and different plasma acetate and propionate levels. Future research should disentangle cause and effect and whether supplementation of SCFA-producing bacteria or SCFA alone can have disease-modifying effects in T1D.

The portal-drained viscera release fibroblast growth factor 19 in humans

Fibroblast growth factor 19 (FGF19) is an ileum‐derived endrocrine factor that is produced in response to transepithelial bile salt flux. FGF19 represses bile salt synthesis in the liver. Despite the general assumption that FGF19 signals to the liver via portal blood, no human data are available to support this notion. The aim was to study portal FGF19 levels, and determined bile salt and FGF19 fluxes across visceral organs in humans. Bile salt and FGF19 levels were assessed in arterial, portal, and hepatic venous blood collected from fasted patients who underwent partial liver resection for colorectal liver metastases (n = 30). Fluxes across the portal‐drained viscera (PDV), liver, and splanchnic area were calculated. Portal bile salt levels (7.8 [5.0–12.4] μmol/L) were higher than levels in arterial (2.7 [1.7–5.5] μmol/L, P < 0.0001) and hepatic venous blood (3.4 [2.5–6.5] μmol/L, P < 0.0001). Bile salts released by the PDV (+1.2 [+0.7–+2.0] mmol kg⁻¹ h⁻¹, P < 0.0001) were largely taken up by the liver (−1.0 [−1.8 to −0.4] mmol kg⁻¹ h⁻¹, P < 0.0001). Portal levels of FGF19 (161 ± 78 pg/mL) were higher than arterial levels (135 ± 65 pg/mL, P = 0.046). A net release of FGF19 by the PDV (+4.0 [+2.1 to +9.9] ng kg⁻¹ h⁻¹, P < 0.0001) was calculated. There was no significant flux of FGF19 across the liver (−0.2 [−3.7 to +7.4] ng kg⁻¹ h⁻¹, P = 0.93). In conclusion, FGF19 levels in human portal blood are higher than in arterial blood. FGF19 is released by the portal‐drained viscera under fasted steady state conditions.

Improvement of Insulin Sensitivity after Lean Donor Feces in Metabolic Syndrome Is Driven by Baseline Intestinal Microbiota Composition

The intestinal microbiota has been implicated in insulin resistance, although evidence regarding causality in humans is scarce. We therefore studied the effect of lean donor (allogenic) versus own (autologous) fecal microbiota transplantation (FMT) to male recipients with the metabolic syndrome. Whereas we did not observe metabolic changes at 18 weeks after FMT, insulin sensitivity at 6 weeks after allogenic FMT was significantly improved, accompanied by altered microbiota composition. We also observed changes in plasma metabolites such as γ-aminobutyric acid and show that metabolic response upon allogenic FMT (defined as improved insulin sensitivity 6 weeks after FMT) is dependent on decreased fecal microbial diversity at baseline. In conclusion, the beneficial effects of lean donor FMT on glucose metabolism are associated with changes in intestinal microbiota and plasma metabolites and can be predicted based on baseline fecal microbiota composition.

ERAS: Improving outcome in the cachectic HPB patient

The enhanced recovery after surgery (ERAS) program has reduced postoperative morbidity and duration of hospital stay but not mortality in patients undergoing hepatopancreatobiliary (HPB) surgery. Many HPB patients suffer from cancer cachexia, a syndrome of severe weight and muscle loss. This may affect outcomes of HPB surgery even within an ERAS program. A tailored ERAS approach may be essential in further improving outcome in this vulnerable patient category.

Psoas muscle area is not representative of total skeletal muscle area in the assessment of sarcopenia in ovarian cancer

BACKGROUND

Computed tomography measurements of total skeletal muscle area can detect changes and predict overall survival (OS) in patients with advanced ovarian cancer. This study investigates whether assessment of psoas muscle area reflects total muscle area and can be used to assess sarcopenia in ovarian cancer patients.

METHODS

Ovarian cancer patients (n = 150) treated with induction chemotherapy and interval debulking were enrolled retrospectively in this longitudinal study. Muscle was measured cross sectionally with computed tomography in three ways: (i) software quantification of total skeletal muscle area (SMA); (ii) software quantification of psoas muscle area (PA); and (iii) manual measurement of length and width of the psoas muscle to derive the psoas surface area (PLW). Pearson correlation between the different methods was studied. Patients were divided into two groups based on the extent of change in muscle area, and agreement was measured with kappa coefficients. Cox-regression was used to test predictors for OS.

RESULTS

Correlation between SMA and both psoas muscle area measurements was poor (r = 0.52 and 0.39 for PA and PLW, respectively). After categorizing patients into muscle loss or gain, kappa agreement was also poor for all comparisons (all κ < 0.40). In regression analysis, SMA loss was predictive of poor OS (hazard ratio 1.698 (95%CI 1.038-2.778), P = 0.035). No relationship with OS was seen for PA or PLW loss.

CONCLUSIONS

Change in psoas muscle area is not representative of total muscle area change and should not be used to substitute total skeletal muscle to predict survival in patients with ovarian cancer.

Detection of Localized Hepatocellular Amino Acid Kinetics by using Mass Spectrometry Imaging of Stable Isotopes

Mass spectrometry imaging (MSI) simultaneously detects and identifies the spatial distribution of numerous molecules throughout tissues. Currently, MSI is limited to providing a static and ex vivo snapshot of highly dynamic systems in which molecules are constantly synthesized and consumed. Herein, we demonstrate an innovative MSI methodology to study dynamic molecular changes of amino acids within biological tissues by measuring the dilution and conversion of stable isotopes in a mouse model. We evaluate the method specifically on hepatocellular metabolism of the essential amino acid l-phenylalanine, associated with liver diseases. Crucially, the method reveals the localized dynamics of l-phenylalanine metabolism, including its in vivo hydroxylation to l-tyrosine and co-localization with other liver metabolites in a time course of samples from different animals. This method thus enables the dynamics of localized biochemical synthesis to be studied directly from biological tissues.

Low skeletal muscle radiation attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer

BACKGROUND

Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas.

METHODS

A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle radiation attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle radiation attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo-Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively.

RESULTS

Low muscle radiation attenuation was associated with shorter survival in comparison with moderate and high muscle radiation attenuation [median survival 10.8 (95% CI: 8.8-12.8) vs. 17.4 (95% CI: 14.7-20.1), and 18.5 (95% CI: 9.2-27.8) months, respectively; P < 0.008]. Patient subgroups with high muscle radiation attenuation combined with either low visceral adipose tissue or age <70 years had longer survival than other subgroups (P = 0.011 and P = 0.001, respectively). Muscle radiation attenuation was inversely correlated with intermuscular adipose tissue (r_p  = -0.697, P < 0.001). High visceral adipose tissue was associated with an increased surgical site infection rate, OR: 2.4 (95% CI: 1.1-5.3; P = 0.027).

CONCLUSIONS

Low muscle radiation attenuation was associated with reduced survival, and high visceral adiposity was associated with an increase in surgical site infections. The strong correlation between muscle radiation attenuation and intermuscular adipose tissue suggests the presence of ectopic fat in muscle, warranting further investigation. CT image analysis could be implemented in pre-operative risk assessment to assist in treatment decision-making.

Low-Dose Lipopolysaccharide Causes Biliary Injury by Blood Biliary Barrier Impairment in a Rat Hepatic Ischemia/Reperfusion Model

This study explored whether bacterial endotoxins, in the form of lipopolysaccharides (LPS), could have an injurious effect on the biliary tract in conjunction with ischemia. A total of 64 rats were randomly assigned to 4 groups: sham operation (sham group), 1 mg/kg LPS intraperitoneal (LPS group), hepatic ischemia/reperfusion (IR; IR group), and IR combined with LPS (IR+LPS group). Following 1 or 6 hours of reperfusion, serum liver tests, bile duct histology, immunofluorescence microscopy (zonula occludens-1 [ZO-1]), bile composition (bile salts, phospholipids, lactate dehydrogenase), hepatic gene expression (bile salt transporters and inflammatory mediators), as well as serum and biliary cytokine concentrations were quantified and compared between the study groups. In addition, the integrity of the blood biliary barrier (BBB) was assayed in vivo using horseradish peroxidase (HRP). LPS administration induced severe small bile duct injury following 6 hours of reperfusion. Furthermore, total bile salts and bilirubin concentrations in serum were increased in the LPS groups compared with sham controls (LPS, + 3.3-fold and +1.9-fold; IR+LPS, + 3.8-fold and +1.7-fold, respectively). The BBB was impaired in the LPS groups as evidenced by elevated levels of HRP in bile (+4.9-fold), and decreased expression of claudin 1 (-6.7-fold) and claudin 3 (-3.6-fold). LPS was found to be a potent inducer of small bile duct injury following hepatic ischemia and 6 hours of reperfusion. This injury was associated with increased permeability of the BBB and impaired hepatic bile salt clearance. Liver Transplantation 23 194-206 2017 AASLD.

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.

Validation of the peak bilirubin criterion for outcome after partial hepatectomy

INTRODUCTION

Postoperative liver failure (PLF) is a dreaded complication after partial hepatectomy. The peak bilirubin criterion (>7.0 mg/dL or ≥120 μmol/L) is used to define PLF. This study aimed to validate the peak bilirubin criterion as postoperative risk indicator for 90-day liver-related mortality.

METHODS

Characteristics of 956 consecutive patients who underwent partial hepatectomy at the Maastricht University Medical Centre or Royal Free London between 2005 and 2012 were analyzed by uni- and multivariable analyses with odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Thirty-five patients (3.7%) met the postoperative peak bilirubin criterion at median day 19 with a median bilirubin level of 183 [121-588] μmol/L. Sensitivity and specificity for liver-related mortality after major hepatectomy were 41.2% and 94.6%, respectively. The positive predictive value was 22.6%. Predictors of liver-related mortality were the peak bilirubin criterion (p < 0.001, OR = 15.9 [95%CI 5.2-48.7]), moderate-severe steatosis and fibrosis (p = 0.013, OR = 8.5 [95%CI 1.6-46.6]), ASA 3-4 (p = 0.047, OR = 3.0 [95%CI 1.0-8.8]) and age (p = 0.044, OR = 1.1 [95%CI 1.0-1.1]).

CONCLUSION

The peak bilirubin criterion has a low sensitivity and positive predictive value for 90-day liver-related mortality after major hepatectomy.

Parenteral nutrition dysregulates bile salt homeostasis in a rat model of parenteral nutrition-associated liver disease

BACKGROUND & AIMS

Parenteral nutrition (PN), a lifesaving therapy in patients with intestinal failure, has been associated with hepatobiliary complications including steatosis, cholestasis and fibrosis, collectively known as parenteral nutrition-associated liver disease (PNALD). To date, the pathogenesis of PNALD is poorly understood and therapeutic options are limited. Impaired bile salt homeostasis has been proposed to contribute PNALD. The objective of this study was to establish a PNALD model in rats and to evaluate the effects of continuous parenteral nutrition (PN) on bile salt homeostasis.

METHODS

Rats received either PN via the jugular vein or received normal diet for 3, 7 or 14 days. Serum biochemistry, hepatic triglycerides, circulating bile salts and C4, IL-6 and TNF-alpha, and lipogenic and bile salt homeostatic gene expression in liver and ileum were assessed.

RESULTS

PN increased hepatic triglycerides already after 3 days of administration, and resulted in conjugated bilirubin elevation after 7 or more days. This indicates PN-induced steatosis and impaired canalicular secretion of bilirubin, the latter which is in line with reduced hepatic expression of Mrp2 mRNA. There was no histological evidence for liver inflammation after PN administration, and circulating levels of pro-inflammatory cytokines IL-6 and TNF-α, were comparable in all groups. Hepatic expression of Fxr mRNA was decreased after 7 days of PN, without apparent effect on expression of Fxr targets Bsep and Shp. Nonetheless, Cyp7a1 expression was reduced after 7 days of PN, indicative for lowered bile salt synthesis. Circulating levels of C4 (marker of bile salt synthesis) were also decreased after 3, 7 and 14 days of PN. Levels of circulating bile salts were not affected by PN.

CONCLUSIONS

This study showed that PN in rats caused early mild steatosis and cholestasis, while hepatic and systemic inflammation were not present. The onset of these abnormalities was associated with alterations in bile salt synthesis and transport. This animal model serves as an experimental model to further investigate the pathogenesis of PNALD inflicted by steatosis and cholestasis.

Cholangiocarcinoma, gone without the Wnt?

Cholangiocarcinoma (CCA) is a relatively rare malignancy of the intra- or extra-hepatic bile ducts that is classified according to its anatomical localization as intrahepatic, perihilar or distal. Overall, CCA has a dismal prognosis due to typical presentation at an advanced irresectable stage, lack of effective non-surgical treatments, and a high rate of disease recurrence. CCA frequently arises on a background of chronic liver inflammation and cholestasis. Chronic inflammation is accompanied by enhanced cell turnover with generation of additional inflammatory stimuli, and a microenvironment rich in pro-inflammatory mediators and proliferative factors that enable accumulation of mutations, transformation and expansion of mutated cells. A recent study by Boulter et al implicates the Wnt signaling cascade in cholangiocarcinogenesis. Wnt ligands Wnt7B and Wnt10A were found to be highly overexpressed in human CCA tissue. Wnt7B protein was present throughout the tumor stroma, and often co-localized with a subset of CD68⁺ macrophages. To address in a direct manner whether Wnt signaling is engaged in development of CCA, Boulter et al explored the Wnt signaling pathway in an experimental model that recapitulates the multi-stage progression of human CCA. Wnt ligands found to be elevated in human CCA were also upregulated during the course of CCA development following thioacetamide treatment. Wnt10a increased during the (pre-cancerous) regenerative phase, while Wnt7b induction paralleled tumor growth. Along with upregulation of target genes, the findings demonstrate that the canonical Wnt pathway is progressively activated during cholangio-carcinogenesis. Macrophage depletion, eliminating a major source of Wnt7b, prevented activation of the canonical Wnt cascade, and resulted in reduced number and volume of tumors in this model. Moreover, specific inhibitors of the canonical Wnt pathway (ICG-001 and C-59) caused reduction of tumor area and number, in xenograft and thioacetamide models of CCA. The aggregated findings show that experimental, and presumably human CCA, is a Wnt-driven tumor. Modulation of Wnt signaling, alone or in combination with surgical or chemotherapy approaches, holds promise in the management of this fatal malignancy.

Loss of skeletal muscle during neoadjuvant chemotherapy is related to decreased survival in ovarian cancer patients

BACKGROUND

Malnutrition, weight loss, and muscle wasting (sarcopenia) are common among women with advanced ovarian cancer and have been associated with adverse clinical outcomes and survival. Our objective is to investigate overall survival (OS) related to changes in skeletal muscle (SM) for patients with advanced ovarian cancer treated with neoadjuvant chemotherapy and interval debulking.

METHODS

Ovarian cancer patients (n = 123) treated with neoadjuvant chemotherapy and interval debulking in the area of Maastricht (the Netherlands) between 2000 and 2014 were included retrospectively. Surface areas of SM and adipose tissue were defined on computed tomography at the level of the third lumbar vertebra. Low SM at baseline and SM changes during chemotherapy were compared with Kaplan Meier curves, and Cox-regression models were applied to test predictors of OS.

RESULTS

Median OS for patients who lost SM (n = 83) was 916 ± 99 days, which was significantly different from median OS for patients who maintained or gained SM (n = 40), which was 1431 ± 470 days (P = 0.004). Loss of SM was also a significant predictor of OS in multivariable Cox-regression analysis (hazard ratio 1.773 (95%CI: 1.018-3.088), P = 0.043). Low baseline SM did not influence survival.

CONCLUSIONS

Patients with ovarian cancer have a worse survival when they lose SM during neoadjuvant chemotherapy. Evaluation of low SM at a specific time point is not prognostic for OS. External and prospective validation of these findings is imperative. Nutritional, pharmacological, and/or physical intervention studies are necessary to establish whether SM impairment can be prevented to prolong ovarian cancer survival.

Effects of Gut Microbiota Manipulation by Antibiotics on Host Metabolism in Obese Humans: A Randomized Double-Blind Placebo-Controlled Trial

The gut microbiota has been implicated in obesity and cardiometabolic diseases, although evidence in humans is scarce. We investigated how gut microbiota manipulation by antibiotics (7-day administration of amoxicillin, vancomycin, or placebo) affects host metabolism in 57 obese, prediabetic men. Vancomycin, but not amoxicillin, decreased bacterial diversity and reduced Firmicutes involved in short-chain fatty acid and bile acid metabolism, concomitant with altered plasma and/or fecal metabolite concentrations. Adipose tissue gene expression of oxidative pathways was upregulated by antibiotics, whereas immune-related pathways were downregulated by vancomycin. Antibiotics did not affect tissue-specific insulin sensitivity, energy/substrate metabolism, postprandial hormones and metabolites, systemic inflammation, gut permeability, and adipocyte size. Importantly, energy harvest, adipocyte size, and whole-body insulin sensitivity were not altered at 8-week follow-up, despite a still considerably altered microbial composition, indicating that interference with adult microbiota by 7-day antibiotic treatment has no clinically relevant impact on metabolic health in obese humans.

The role of bile salts in liver regeneration

A growing body of evidence has demonstrated that bile salts are important for liver regeneration following partial hepatectomy. The relative bile salt overload after partial liver resection causes activation of bile salt receptors in non-parenchymal (viz. the plasma membrane receptor TGR5) and parenchymal (viz. the intracellular receptor FXR) cells in the liver, thus, providing signals to the regenerative process. Impaired bile salt signaling in mice with genetic deficiency of Tgr5 or Fxr results in delayed liver regeneration after partial hepatectomy, and is accompanied by mortality in case of Fxr knock-out mice. Conversely, compensatory liver re-growth in hepatectomized mice can be stimulated by feeding of bile salts or alisol B 23-acetate, a natural triterpenoid agonist of Fxr. A large number of animal studies underscore the importance of strict maintenance of bile salt homeostasis for proper progression of liver regeneration. Both ileal and hepatic Fxr play a key role in regulation of bile salt homeostasis and, thus, preventing hepatotoxicity caused by excessive levels of bile salts. They further contribute to liver regeneration by induction of mitogenic factors. Agents that target bile salt receptors hold promise as drugs to stimulate liver regeneration in selected patients.

Sarcopenia, obesity and sarcopenic obesity: effects on liver function and volume in patients scheduled for major liver resection

BACKGROUND

Sarcopenia, obesity and sarcopenic obesity have been linked to impaired outcome after liver surgery. Preoperative liver function of sarcopenic, obese and sarcopenic-obese patients might be reduced, possibly leading to more post-operative morbidity. The aim of this study was to explore whether liver function and volume were influenced by body composition in patients undergoing liver resection.

METHODS

In 2011 and 2012, all consecutive patients undergoing the methacetin breath liver function test were included. Liver volumetry and muscle mass analysis were performed using preoperative CT scans and Osirix(®) software. Muscle mass and body-fat% were calculated. Predefined cut-off values for sarcopenia and the top two body-fat% quintiles were used to identify sarcopenia and obesity, respectively. Histologic assessment of the resected liver gave insight in background liver disease.

RESULTS

A total number of 80 patients were included. Liver function and volume were comparable in sarcopenic(-obese) and non-sarcopenic(-obese) patients. Obese patients showed significantly reduced liver function [295 (95-508) vs. 358 (96-684) µg/kg/h, P = 0.018] and a trend towards larger liver size [1694 (1116-2685) vs. 1533 (869-2852) mL, P = 0.079] compared with non-obese patients. Weight (r = -0.40), body surface area (r = -0.32), estimated body-fat% (r = -0.43) and body mass index (r = -0.47) showed a weak but significant negative (all P < 0.05) correlation with liver function. Moreover, body-fat% was identified as an independent factor negatively affecting the liver function.

CONCLUSION

Sarcopenia and sarcopenic obesity did not seem to influence liver size and function negatively. However, obese patients had larger, although less functional, livers, indicating dissociation of liver function and volume in these patients.

Are sarcopenia, obesity and sarcopenic obesity predictive of outcome in patients with colorectal liver metastases?

BACKGROUND

The impact of body composition on outcomes after surgery for colorectal liver metastases (CRLM) remains unclear. The aim of the present study was to determine the influence of sarcopenia, obesity and sarcopenic obesity on morbidity, disease-free (DFS) and overall survival (OS).

METHOD

Between 2005 and 2012, all patients undergoing a partial liver resection for CRLM in the Maastricht University Medical Centre, and who underwent computed tomography (CT) imaging within 3 months before liver surgery, were included. Body composition was primarily based on pre-operative CT measurements. Sarcopenia was based on total muscle area at the level of the third lumbar vertebra and predefined body mass index (BMI)- and gender-specific cut-off values for sarcopenia were used. Body fat percentages were calculated and the top 40% for men and women were considered obese.

RESULTS

Of the 171 included patients undergoing liver surgery for CRLM, 80 (46.8%) patients were sarcopenic, 69 (40.4%) obese and 49 (28.7%) sarcopenic obese. The presence of sarcopenia, obesity or sarcopenic obesity did not affect the complication rates. However, readmission rates were significantly increased in patients with (sarcopenic) obesity (P < 0.05). Surprisingly, obesity seemed to prolong OS (P = 0.021) and was identified as an independent predictor [hazard ratio (HR):0.58 and P = 0.046] for better OS. Sarcopenia and sarcopenic obesity did not affect DFS or OS.

CONCLUSION

Sarcopenia, obesity and sarcopenic obesity did not worsen DFS, OS and complication rates after a partial liver resection for CRLM.

Effect of toll-like receptor 7 and 9 targeted therapy to prevent the development of hepatocellular carcinoma

BACKGROUND & AIMS

Chronic liver disease is a predisposing factor for development of hepatocellular carcinoma (HCC). Toll-like receptors play a crucial role in immunity against microbial pathogens and recent evidence suggests that they may also be important in pathogenesis of chronic liver disease. The purpose of this study was to determine whether TLR7 and TLR9 are potential targets for prevention and progression of HCC.

METHODS

Tissue microarrays containing liver samples from patients with cirrhosis, viral hepatitis and HCC were examined for expression of TLR7 and TLR9 and the data obtained was validated in liver specimens from the hospital archives. Proliferation of human HCC cell lines was studied following stimulation of TLR7 and TLR9 using agonists (imiquimod and CpG-ODN respectively) and inhibition with a specific antagonist (IRS-954) or chloroquine. The effect of these interventions was confirmed in a xenograft model and diethylnitrosamine (DEN)/nitrosomorpholine (NMOR)-induced model of HCC.

RESULTS

TLR7 and TLR9 expression was up-regulated in human HCC tissue. Proliferation of HuH7 cells in vitro increased significantly in response to stimulation of TLR7. TLR7 and TLR9 inhibition using IRS-954 or chloroquine significantly reduced HuH7 cell proliferation in vitro and inhibited tumour growth in the mouse xenograft model. HCC development in the DEN/NMOR rat model was also significantly inhibited by chloroquine (P < 0.001).

CONCLUSION

The data suggest that inhibiting TLR7 and TLR9 with IRS-954 or chloroquine could potentially be used as a novel therapeutic approach for preventing HCC development and/or progression in susceptible patients.

Development of a composite endpoint for randomized controlled trials in pancreaticoduodenectomy

BACKGROUND

Few randomized controlled trials (RCTs) have been performed in patients undergoing pancreaticoduodenectomy (PD). An important factor contributing to this is the large number of patients needed to adequately power RCTs for relevant clinical single endpoints. A PD-specific composite endpoint (CEP) could solve this problem. The aim of the present study was to develop a PD-specific CEP, consisting of complications related to PD, allowing reduction in sample sizes and improving the ability to compare outcomes.

METHODS

PD-specific CEP components were selected after a systematic review of the literature and consensus between 25 international pancreatic surgeons. Ultimately, prospective cohorts of patients who underwent PD in two high-volume HPB centers (London, UK, and Maastricht, NL) were used to assess the event rate and effect of implementing a PD-specific CEP.

RESULTS

From a total of 18 single-component endpoints, intra-abdominal abscess, sepsis, post-PD hemorrhage, bile leakage, gastrojejunostomy leakage, leakage of the pancreatic anastomosis, delayed gastric emptying, and operative mortality within 90 days were selected to be included the PD-specific CEP. All eight components had consensus definitions and a Dindo-Clavien classification of 3 or more. The incidence of the PD-specific CEP was 24.7 % in the Maastricht cohort and 23.3 % in the London cohort. These incidence rates led to a twofold reduction in the theoretical calculated sample size for an adequately powered RCT on PD using this CEP as a primary endpoint.

CONCLUSIONS

The proposed PD-specific CEP enables clinical investigators to adequately power RCTs on PD and increases the feasibility, comparability, and utility in meta-analysis.

Improving outcome after pancreaticoduodenectomy: experiences with implementing an enhanced recovery after surgery (ERAS) program

BACKGROUND

Pancreaticoduodenectomies (PDs) are complex surgical procedures that require high-standard perioperative care. The objective of this study was to evaluate the effects of implementing an Enhanced Recovery After Surgery (ERAS) program for PD on patient outcome.

METHODS

230 patients undergoing PD in the Maastricht University Medical Centre between January 1995 and January 2012 were included. Group 1 (no ERAS; 1995-2005) received traditional care. From January 2006, several elements of an ERAS pathway for pancreatic surgery were implemented (group 2: 'ERAS-like'). From 2009 onwards the ERAS pathway was fully implemented (group 3: ERAS). Mortality, complications, readmissions and length of hospital stay (LOS) were evaluated in the subgroups and compared.

RESULTS

Median LOS was significantly reduced from 20 days in group 1 to 13 days in group 2 and 14 days in group 3 (p = 0.001). Median LOS of patients without complications was 16, 10 and 9 days in groups 1, 2 and 3, respectively (p < 0.0001). Over time, the average age of patients undergoing PD increased significantly. Complication rates as well as mortality and readmission rates did not change over time.

CONCLUSION

Implementing an ERAS program contributed to a decrease of LOS without compromising other outcomes. Mortality, morbidity and readmission rates stayed unchanged and more complications were managed non-operatively.

Identification and validation of risk factors for postoperative infectious complications following hepatectomy

Postoperative infectious complications (PICs) are associated with significant morbidity after abdominal surgery. Using multivariate analysis of data from a prospective database, our study focused on the risk factors for PICs and the prevention of these complications after hepatectomy, with the goal of improving outcomes and reducing the length of hospital stays.

BACKGROUND

PICs following surgery are associated with significant morbidity, increase the length of hospital stays, and have a negative impact on long-term oncological outcome. The aim of this study was to determine the risk factors for PICs following partial hepatectomy and to validate these results with an external database.

METHODS

Between January 2006 and December 2009, 555 patients underwent elective partial hepatectomy. We prospectively collected and retrospectively analyzed demographic data, pathological variables, associated pathological conditions, and preoperative, intraoperative, and postoperative variables. The dependent variables studied were the occurrence of PICs, defined as development of one or more of the following conditions: pneumonia, sepsis, Central line-associated bloodstream infection, urinary tract infection, wound infection, and infected intra-abdominal fluid collection. PICs were devised in medical (PIMCs) and surgical (PISCs) complications. The incidence of PICs and validation of the predictive score were determined using an external prospective database of 342 patients.

RESULTS

The multivariate analysis identified three independent risk factors for PICs: the presence of a nasogastric tube (OR = 1.8), blood transfusion (OR = 1.9), and diabetes (OR = 2.4). The multivariate analysis identified only one independent risk factor for PISCs: an associated portal venous resection (OR = 5.5). The multivariate analysis identified four independent risk factors for PIMCs: presence of a biliary drainage (OR = 1.9), blood transfusion (OR = 2.1), diabetes (OR = 2.9), and presence of atrial fibrillation (OR = 3.6). According to the three predictive factors, the observed rates of PICs ranged from 18.8 % to 77.8 % and ranged from 24.2 % to 100 % in the external database. Predicted and observed risks of PICs were not statistically different.

CONCLUSIONS

The correction of modifiable risk factors among the identified factors could reduce the incidence of PICs and, as a consequence, improve patient outcomes and reduce the length of hospital stays.

The gut-liver axis

PURPOSE OF REVIEW

The liver adaptively responds to extra-intestinal and intestinal inflammation. In recent years, the role of the autonomic nervous system, intestinal failure and gut microbiota has been investigated in the development of hepatic, intestinal and extra-intestinal disease.

RECENT FINDINGS

The autonomic nervous system can be stimulated via enteral fat leading to cholecystokinin release, stimulating receptors in the gut and in the brain. This promotes bowel integrity, dampening the inflammatory response to food antigens. Consensus exists that intravenously administered long-chain fatty acids can cause liver damage but randomized-controlled trials are lacking. Disruption of the enterohepatic circulation of bile salts can give rise to cholestasis and nonalcoholic fatty liver disease, which may progress to fibrosis and cirrhosis. Reduced intestinal availability of bile salts reduces stimulation of the farnesoid X receptor. This may induce hepatic bile salt overload and associated hepatotoxicity through reduced action of intestinal fibroblast growth factor 19. Evidence is put forward to suggest that the intestinal microbiota is associated with liver abnormalities.

SUMMARY

Enteral lipids reduce inflammation and liver damage during stress or systemic inflammation, whereas parenteral lipid is associated with liver damage. Maintaining the enterohepatic circulation of bile salts limits hepatic cholestasis through an farnesoid X receptor feedback pathway. Changes in gut microbiota composition may induce liver disease.