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.

Treatment of Staphylococcus aureus biofilm infection by the quorum-sensing inhibitor RIP

The quorum-sensing inhibitor RIP inhibits staphylococcal TRAP/agr systems and both TRAP- and agr-negative strains are deficient in biofilm formation in vivo, indicating the importance of quorum sensing to biofilms in the host. RIP injected systemically into rats has been found to have strong activity in preventing methicillin-resistant Staphylococcus aureus graft infections, suggesting that RIP can be used as a therapeutic agent.

Use of the quorum-sensing inhibitor RNAIII-inhibiting peptide to prevent biofilm formation in vivo by drug-resistant Staphylococcus epidermidis

Staphylococcus epidermidis is a frequent cause of infections associated with foreign bodies and indwelling medical devices. The bacteria are capable of surviving antibiotic treatment through encapsulation into biofilms. RNAIII-inhibiting peptide (RIP) is a heptapeptide that inhibits S. aureus pathogenesis by disrupting quorum-sensing mechanisms. In this study, RIP inhibited drug-resistant S. epidermidis biofilm formation through a mechanism similar to that evidenced for S. aureus. RIP is synergistic with antibiotics in eliminating 100% of graft-associated in vivo S. epidermidis infections, which suggests that RIP may be used to coat medical devices to prevent staphylococcal infections. Disruption of cell-cell communication can prevent infections associated with antibiotic-resistant strains.

LL-37 protects rats against lethal sepsis caused by gram-negative bacteria

We investigated the efficacy of LL-37, the C-terminal part of the only cathelicidin in humans identified to date (termed human cationic antimicrobial protein), in three experimental rat models of gram-negative sepsis. Adult male Wistar rats (i) were given an intraperitoneal injection of 1 mg Escherichia coli 0111:B4 LPS, (ii) were given 2 x 10(10) CFU of Escherichia coli ATCC 25922, or (iii) had intra-abdominal sepsis induced via cecal ligation and puncture. For each model, all animals were randomized to receive intravenously isotonic sodium chloride solution, 1-mg/kg LL-37, 1-mg/kg polymyxin B, 20-mg/kg imipenem, or 60-mg/kg piperacillin. Lethality; growth of bacteria in blood, peritoneum, spleen, liver, and mesenteric lymph nodes; and endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma were evaluated. All compounds reduced lethality compared to levels in controls. Endotoxin and TNF-alpha plasma levels were significantly higher in conventional antibiotic-treated rats than in LL-37- and polymyxin B-treated animals. All drugs tested significantly reduced bacterial growth compared to saline treatment. No statistically significant differences between LL-37 and polymyxin B were noted for antimicrobial and antiendotoxin activities. LL-37 and imipenem proved to be the most effective treatments in reducing all variables measured. Due to its multifunctional properties, LL-37 may become an important future consideration for the treatment of sepsis.

Assessment of Textbook Outcome in Laparoscopic and Open Liver Surgery

Importance

Textbook outcome (TO) is a composite measure that captures the most desirable surgical outcomes as a single indicator, yet to date TO has not been defined and assessed in the field of laparoscopic liver resection (LLR) and open liver resection (OLR).

Objective

To obtain international agreement on the definition of TO in liver surgery (TOLS) and to assess the incidence of TO in LLR and OLR in a large international multicenter database using a propensity-score matched analysis.

Design, Setting, and Participants

Patients undergoing LLR or OLR for all liver diseases between January 2011 and October 2019 were analyzed using a large international multicenter liver surgical database. An international survey was conducted among all members of the European-African Hepato-Pancreato-Biliary Association (E-AHPBA) and International Hepato-Pancreato-Biliary Association (IHPBA) to reach agreement on the definition of TOLS. The rate of TOLS was assessed for LLR and OLR before and after propensity-score matching. Factors associated with achieving TOLS were investigated.

Main Outcomes and Measures

Textbook outcome, with TOLS defined as the absence of intraoperative incidents of grade 2 or higher, postoperative bile leak grade B or C, severe postoperative complications, readmission within 30 days after discharge, in-hospital mortality, and the presence of R0 resection margin.

Results

A total of 8188 patients (4559 LLR; median age, 65 years [interquartile range, 55-73 years]; 2529 were male [55.8%] and 3629 OLR; median age, 64 years [interquartile range, 56-71 years]; 2204 were male [60.7%]) were included in the analysis of whom 69.1% achieved TOLS; 74.8% for LLR and 61.9% for OLR (P < .001). On multivariable analysis, American Society of Anesthesiologists grade III, previous abdominal surgery, histological diagnosis of colorectal liver metastases (odds ratio [OR], 0.656 [95% CI, 0.457-0.940]; P = .02), cholangiocarcinoma, non-CRLM, a tumor size of 30 mm or more, minor resection of posterior/superior segments (OR, 0.716 [95% CI, 0.577-0.887]; P = .002), anatomically major resection (OR, 0.579 [95% CI, 0.418-0.803]; P = .001), and nonanatomical resection (OR, 0.612 [95% CI, 0.476-0.788]; P < .001) were associated with a worse TOLS rate after LLR. For OLR, only histological diagnosis of cholangiocarcinoma (OR, 0.360 [95% CI, 0.214-0.607]; P < .001) and a tumor size of 30 mm or more (30-50 mm = OR, 0.718 [95% CI, 0.565-0.911]; P = .01; 50.1-100 mm = OR, 0.729 [95% CI, 0.554-0.960]; P = .02; >10 cm = OR, 0.550 [95% CI, 0.366-0.826]; P = .004) were associated with a worse TOLS rate.

Conclusions and Relevance

In this multicenter study, TOLS was found to be a useful tool for assessing patient-level hospital performance and may have utility in optimizing patient outcomes after LLR and OLR.

Intention-to-treat survival benefit of liver transplantation in patients with hepatocellular cancer

The debate about the best approach to select patients with hepatocellular cancer (HCC) waiting for liver transplantation (LT) is still ongoing. This study aims to identify the best variables allowing to discriminate between "high-" and "low-benefit" patients. To do so, the concept of intention-to-treat (ITT) survival benefit of LT has been created. Data of 2,103 adult HCC patients consecutively enlisted during the period 1987-2015 were analyzed. Three rigorous statistical steps were used in order to create the ITT survival benefit of LT: the development of an ITT LT and a non-LT survival model, and the individual prediction of the ITT survival benefit of LT defined as the difference between the median ITT survival with (based on the first model) and without LT (based on the second model) calculated for each enrolled patient. Four variables (Model for End-Stage Liver Disease, alpha-fetoprotein, Milan-Criteria status, and radiological response) displayed a high effect in terms of delta benefit. According to these risk factors, four benefit groups were identified. Patients with three to four factors ("no-benefit group"; n = 405 of 2,103; 19.2%) had no benefit of LT compared to alternative treatments. Conversely, patients without any risk factor ("large-benefit group"; n = 108; 5.1%) yielded the highest benefit from LT reaching 60 months.

CONCLUSION

The ITT transplant survival benefit presented here allows physicians to better select HCC patients waiting for LT. The obtained stratification may lead to an improved and more equitable method of organ allocation. Patients without benefit should be de-listed, whereas patients with large benefit ratio should be prioritized for LT. (Hepatology 2017;66:1910-1919).

RNA III inhibiting peptide inhibits in vivo biofilm formation by drug-resistant Staphylococcus aureus

Staphylococcus aureus is a prevalent cause of bacterial infections associated with indwelling medical devices. RNA III inhibiting peptide (RIP) is known to inhibit S. aureus pathogenesis by disrupting quorum-sensing mechanisms. RIP was tested in the present study for its ability to inhibit S. aureus biofilm formation in a rat Dacron graft model. The activity of RIP was synergistic with those of antibiotics for the complete prevention of drug-resistant S. aureus infections.

Indocyanine Green Fluorescence Navigation in Liver Surgery: A Systematic Review on Dose and Timing of Administration

BACKGROUND

Indocyanine green (ICG) fluorescence has proven to be a high potential navigation tool during liver surgery; however, its optimal usage is still far from being standardized.

METHODS

A systematic review was conducted on MEDLINE/PubMed for English articles that contained the information of dose and timing of ICG administration until February 2021. Successful rates of tumor detection and liver segmentation, as well as tumor/patient background and imaging settings were also reviewed. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN).

RESULTS

Out of initial 311 articles, a total of 72 manuscripts were obtained. The quality assessment of the included studies revealed usually low; only 9 articles got qualified as high quality. Forty articles (55%) focused on open resections, whereas 32 articles (45%) on laparoscopic and robotic liver resections. Thirty-four articles (47%) described tumor detection ability, and 25 articles (35%) did liver segmentation ability, and the others (18%) did both abilities. Negative staining was reported (42%) more than positive staining (32%). For tumor detection, majority used the dose of 0.5 mg/kg within 14 days before the operation day, and an additional administration (0.02-0.5 mg/kg) in case of longer preoperative interval. Tumor detection rate was reported to be 87.4% (range, 43%-100%) with false positive rate reported to be 10.5% (range, 0%-31.3%). For negative staining method, the majority used 2.5 mg/body, ranging from 0.025 to 25 mg/body. For positive staining method, the majority used 0.25 mg/body, ranging from 0.025 to 12.5 mg/body. Successful segmentation rate was 88.0% (range, 53%-100%).

CONCLUSION

The time point and dose of ICG administration strongly needs to be tailored case by case in daily practice, due to various tumor/patient backgrounds and imaging settings.

Prophylactic efficacy of topical temporin A and RNAIII-inhibiting peptide in a subcutaneous rat Pouch model of graft infection attributable to staphylococci with intermediate resistance to glycopeptides

BACKGROUND

Bacteria that adhere to implanted medical devices play an important role in industry and in modern medicine. Staphylococci are among the most common pathogens that cause biomaterial infections. Vascular prosthetic graft infection is one of the most feared complications that the vascular surgeon treats, frequently resulting in prolonged hospitalization, organ failure, amputation, and death. A rat model was used to investigate the topical efficacies of temporin A and the quorum-sensing inhibitor RNAIII-inhibiting protein (RIP) as prophylactic agents of vascular prosthetic graft infections caused by Staphylococcus aureus and Staphylococcus epidermidis with intermediate resistance to glycopeptides.

METHODS AND RESULTS

Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses 1 cm2 followed by topical inoculation with 2x10(7) colony-forming units of bacterial strains. The study included, for each staphylococcal strain, a control group (no graft contamination), a contaminated group that did not receive antibiotic prophylaxis, and 6 contaminated groups that received grafts soaked with temporin A, RIP, rifampin, temporin A plus RIP, RIP plus rifampin, or temporin A plus RIP. The infection was evaluated by quantitative agar culture. When tested alone, temporin A and RIP showed comparable efficacies, and their efficacies were significantly higher than that of rifampin against both strains. All combinations showed efficacies significantly higher than that of each single compound. The combinations of temporin A and RIP exerted the strongest antistaphylococcal efficacies, eliminating infection by 100%.

CONCLUSIONS

The results of the present study make these molecules potentially useful for antimicrobial chemoprophylaxis in vascular surgery.

RNAIII‐Inhibiting Peptide Significantly Reduces Bacterial Load and Enhances the Effect of Antibiotics in the Treatment of Central Venous Catheter–AssociatedStaphylococcus aureusInfections

BACKGROUND

Medical devices used in clinical practice are often associated with biofilm-associated staphylococcal infections.

METHODS

An in vitro antibiotic susceptibility assay of Staphylococcus aureus biofilms using 96-well polystyrene tissue-culture plates was performed to test the effects of RNAIII-inhibiting peptide (RIP), ciprofloxacin, imipenem, and vancomycin. Efficacy studies were performed using a rat model of central venous catheter (CVC)-associated infection. Twenty-four hours after implantation, the catheters were filled with RIP (1 mg/mL). Thirty minutes later, rats were challenged, via the CVC, with 1.0 x 10(6) cfu of S. aureus strain Smith diffuse. The antibiotic-lock technique was begun 24 h later.

RESULTS

Minimum inhibitory concentrations of antibiotics in biofilms were at least 4-fold higher than those against the freely growing planktonic cells. When they were first treated with RIP, the cells in biofilms became as susceptible to antibiotics as did planktonic cells. These data were confirmed by the in vivo studies. In particular, when CVCs were treated with both RIP and antibiotics, the biofilm bacterial load was further reduced to 1 x 10(1) cfu/mL, and bacteremia was not detected, suggesting that there was 100% elimination of bacteremia and a 6 log10 reduction in biofilm bacterial load.

CONCLUSION

RIP significantly reduces bacterial load and enhances the effect of antibiotics in the treatment of CVC-associated S. aureus infections.

Interaction of antimicrobial peptide temporin L with lipopolysaccharide in vitro and in experimental rat models of septic shock caused by gram-negative bacteria

Sepsis remains a major cause of morbidity and mortality in hospitalized patients, despite intense efforts to improve survival. The primary lead for septic shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the quest for compounds with antiendotoxin properties is actively pursued. We investigated the efficacy of the amphibian skin antimicrobial peptide temporin L in binding Escherichia coli LPS in vitro and counteracting its effects in vivo. Temporin L strongly bound to purified E. coli LPS and lipid A in vitro, as proven by fluorescent displacement assay, and readily penetrated into E. coli LPS monolayers. Furthermore, the killing activity of temporin L against E. coli was progressively inhibited by increasing concentrations of LPS added to the medium, further confirming the peptide's affinity for endotoxin. Antimicrobial assays showed that temporin L interacted synergistically with the clinically used beta-lactam antibiotics piperacillin and imipenem. Therefore, we characterized the activity of temporin L when combined with imipenem and piperacillin in the prevention of lethality in two rat models of septic shock, measuring bacterial growth in blood and intra-abdominal fluid, endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma, and lethality. With respect to controls and single-drug treatments, the simultaneous administration of temporin L and beta-lactams produced the highest antimicrobial activities and the strongest reduction in plasma endotoxin and TNF-alpha levels, resulting in the highest survival rates.

Prevalence and clinical outcome of hepatic haemangioma with specific reference to the risk of rupture: A large retrospective cross-sectional study

BACKGROUND

Prevalence and incidence of hepatic haemangioma are estimated from autopsy series only. Although benign and generally asymptomatic, hepatic haemangioma can cause serious complications.

AIMS

The aim of the study was to assess the prevalence of hepatic haemangioma and to attempt to quantify the risk of major complications such as spontaneous rupture.

METHODS

We retrospectively analyzed the radiology database of a Regional University Hospital over a 7-year period: the radiological records of 83,181 patients who had an abdominal computed tomography or magnetic resonance scan were reviewed. Diagnoses made at imaging were reviewed and related to clinical course.

RESULTS

Hepatic haemangioma was diagnosed in 2071 patients (2.5% prevalence). In 226 patients (10.9%), haemangioma had diameter of 4 cm or more (giant haemangioma). The risk of bleeding was assessed on patients without concomitant malignancies. Spontaneous bleeding occurred in 5/1067 patients (0.47%). All 5 patients had giant haemangioma: 4 had exophytic lesions and presented with haemoperitoneum; 1 with centrally located tumour experienced intrahepatic bleeding.

CONCLUSION

Giant haemangiomas have a low but relevant risk of rupture (3.2% in this series), particularly when peripherally located and exophytic. Surgery might be considered in these cases.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1^th and the 5^th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Protective effects of the combination of alpha-helical antimicrobial peptides and rifampicin in three rat models of Pseudomonas aeruginosa infection

INTRODUCTION

An experimental study has been performed to compare the in vitro activity and the in vivo efficacy of magainin II and cecropin A with or without rifampicin against control and multidrug-resistant Pseudomonas aeruginosa strains.

METHODS

In vitro experiments included MIC determinations and synergy studies. For in vivo studies, animals were given an intraperitoneal injection of P. aeruginosa lipopolysaccharide, P. aeruginosa ATCC 27853 and one clinical multiresistant P. aeruginosa strain. Groups of animals received intravenously isotonic sodium chloride solution, 10 mg/kg rifampicin, 1 mg/kg magainin II or 1 mg/kg cecropin A. Two groups of animals received a combined treatment with magainin II + rifampicin or cecropin A + rifampicin at the same dosages as the singly treated groups. In addition, a further group was treated with tazobactam/piperacillin (120 mg/kg). Lethality, bacterial growth in blood and peritoneum, and endotoxin and TNF-alpha concentrations in plasma were evaluated.

RESULTS

Combinations of alpha-helical antimicrobial peptides showed in vitro synergistic interaction. Magainin II and cecropin A exerted strong antimicrobial activity and achieved a significant reduction in plasma endotoxin and TNF-alpha concentrations when compared with control and rifampicin-treated groups. Rifampicin exhibited no anti-P. aeruginosa activity and good substantial impact on endotoxin and TNF-alpha plasma concentrations. Combined treatment groups had significant reductions in bacterial count, positive blood cultures and mortality rates when compared with singly treated and control groups.

CONCLUSIONS

Our results highlight the potential usefulness of these combinations that provide future therapeutic alternatives in P. aeruginosa infections.

RNAIII-inhibiting peptide affects biofilm formation in a rat model of staphylococcal ureteral stent infection

Ureteral stents coated with the quorum-sensing inhibitor RNAIII-inhibiting peptide (RIP) were implanted in rat bladders and shown to suppress Staphylococcus aureus formation on the stent and in urine and was especially effective when combined with teicoplanin. Coating ureteral stents with RIP thus increases the efficacy of teicoplanin in preventing ureteral stent-associated staphylococcal infections.

Potential therapeutic role of cationic peptides in three experimental models of septic shock

The therapeutic efficacies of buforin II, indolicidin, and KFFKFFKFF were investigated in three rat models of septic shock: (i) rats injected intraperitoneally with 10 microg of Escherichia coli O111:B4 lipopolysaccharide, (ii) rats given an intraperitoneal injection of 2 x 10(10) CFU of Escherichia coli ATCC 25922, and (iii) rats in which intra-abdominal sepsis was induced via cecal ligation and single puncture. All animals were randomized to receive parenterally isotonic sodium chloride solution, 1 mg of buforin II per kg of body weight, 1 mg of indolicidin per kg, 1 mg of KFFKFFKFF per kg, and 20 mg of imipenem per kg. The main outcome measures were bacterial growth in abdominal exudate and plasma, endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma, and lethality. Treatment with all peptides resulted in significant reductions in plasma endotoxin and TNF-alpha concentrations compared with those resulting from the imipenem and saline treatments. On the other hand, imipenem treatment significantly reduced the levels of bacterial growth compared with the reductions achieved with the peptide and saline treatments. All compounds reduced the rates of death compared to that for the controls. Although the peptides demonstrated lower levels of antimicrobial activity than imipenem, they exhibited the dual properties of antimicrobial and antiendotoxin agents.

Cathelicidin Peptide Sheep Myeloid Antimicrobial Peptide-29 Prevents Endotoxin-induced Mortality in Rat Models of Septic Shock

The present study was designed to investigate the antiendotoxin activity and therapeutic efficacy of sheep myeloid antimicrobial peptide (SMAP)-29, a cathelicidin-derived peptide. The in vitro ability of SMAP-29 to bind LPS from Escherichia coli 0111:B4 was determined using a sensitive limulus chromogenic assay. Two rat models of septic shock were performed: (1) rats were injected intraperitoneally with 1 mg E. coli 0111:B4 LPS and (2) intraabdominal sepsis was induced via cecal ligation and single puncture. All animals were randomized to receive parenterally isotonic sodium chloride solution, 1 mg/kg SMAP-29, 1 mg/kg polymyxin B or 20 mg/kg imipenem. The main outcome measures were: abdominal exudate and plasma bacterial growth, plasma endotoxin and tumor necrosis factor-alpha concentrations, and lethality. The in vitro study showed that SMAP-29 completely inhibited the LPS procoagulant activity at approximately 10 microM peptide concentration. The in vivo experiments showed that all compounds reduced the lethality when compared with control animals. SMAP-29 achieved a substantial decrease in endotoxin and tumor necrosis factor-alpha plasma concentrations when compared with imipenem and saline treatment and exhibited a slightly lower antimicrobial activity than imipenem. No statistically significant differences were noted between SMAP-29 and polymyxin B. SMAP-29, because of its double antiendotoxin and antimicrobial activities, could be an interesting compound for septic shock treatment.

Daptomycin and rifampin alone and in combination prevent vascular graft biofilm formation and emergence of antibiotic resistance in a subcutaneous rat pouch model of staphylococcal infection

OBJECTIVE

To investigate the efficacy of daptomycin and rifampin either alone or in combination in preventing prosthesis biofilm in a rat model of staphylococcal vascular graft infection.

DESIGN

Prospective, randomised, controlled animal study.

MATERIALS

Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses followed by topical inoculation with 2×10(7) colony forming units of Staphylococcus aureus, strain Smith diffuse.

METHODS

The study included a control group, a contaminated group that did not receive any antibiotic prophylaxis and three contaminated groups that received intra-peritoneal daptomycin, rifampin-soaked graft and daptomycin plus rifampin-soaked graft, respectively. Each group included 15 animals. The infection burden was evaluated by using sonication and quantitative agar culture. Moreover, an in vitro antibiotic susceptibility assay for S. aureus biofilms was performed to elucidate the same activity.

RESULTS

When tested alone, daptomycin and rifampin showed good efficacies. Their combination showed efficacies significantly higher than that of each single compound. The in vitro studies showed that minimum inhibitory concentration and minimum bactericidal concentration values for daptomycin were lower in presence of rifampin. Daptomycin prevented the emergence of rifampin resistance.

CONCLUSION

Daptomycin is an important candidate for prevention of staphylococcal biofilm-related infection and rifampin could serve as an interesting anti-staphylococcal antibiotic enhancer.

Doxorubicin-eluting bead vs conventional transcatheter arterial chemoembolization for hepatocellular carcinoma before liver transplantation

AIM: To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization (TACE) on recurrence-free survival after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) and to analyze the effects of TACE on tumor histology.

METHODS: We retrospectively analyzed the histological features of 130 HCC nodules in 63 native livers removed at transplantation. Patients who received any other type of treatment such as radiofrequency tumor ablation, percutaneous ethanol ablation or who were not treated at all were excluded. All patients in the present study were within the Milan Criteria at the last imaging findings before transplantation. Doxorubicin-eluting bead TACE (DEB-TACE) was performed in 22 patients (38 nodules), and conventional TACE (c-TACE) in 16 (25 nodules). Patients’ and tumors’ characteristics were retrospectively reviewed. We performed a per-nodule analysis of the explanted livers to establish the mean percentage of necrosis of any nodule treated by TACE (conventional or DEB) and a per-patient analysis to establish the percentage of necrosis in the cumulative tumor area, including 21 nodules not reached by TACE. Inflammatory and fibrotic changes in the tissue surrounding the tumor nodule were analyzed and categorized as poor/absent, moderate and enhanced reaction. Uni- and multivariate analysis of risk factors for HCC-recurrence were performed.

RESULTS: The number and diameter of the nodules, the time spent on the waiting list and the number of treatments were similar in the two groups. A trend towards higher appropriate response rates (necrosis ≥ 90%) was observed in the DEB-TACE group (44.7% vs 32.0%, P = 0.2834). The mean percentage of necrosis in the cumulative tumor area was 58.8% ± 36.6% in the DEB-TACE group and 50.2% ± 38.1% in the c-TACE group (P = 0.4856). Fibrotic and inflammatory reactions surrounding the tumor nodule were markedly more common in the DEB-TACE group (P < 0.0001, for both the parameters). The three-year recurrence-free survival was higher in DEB-TACE-treated patients than in conventionally treated patients (87.4% vs 61.5%, P = 0.0493). Other factors affecting recurrence-free survival included viable tumor beyond Milan Criteria on histopathological examination, the percentage of necrosis on CTA ≤ 50% and a pre-transplant serum α-fetoprotein level greater than 70 ng/mL. On multivariate analysis, the lack of treatment with DEB-TACE, high levels of α-fetoprotein and viable tumor beyond Milan Criteria at histology examination were identified as independent predictors of tumor recurrence.

CONCLUSION: DEB-TACE can effectively promote tumor necrosis and improves recurrence-free survival after LT in HCC.

Comparative efficacies of quinupristin-dalfopristin, linezolid, vancomycin, and ciprofloxacin in treatment, using the antibiotic-lock technique, of experimental catheter-related infection due to Staphylococcus aureus

We performed in vitro studies to elucidate the bactericidal activity of the antibiotics in an adherent-cell biofilm model. Efficacy studies were performed in a staphylococcal central venous catheter (CVC) infection rat model. Silastic catheters were implanted into the superior cava. Via the CVC the rats were challenged with 1.0 x 10(6) CFU of a live Staphylococcus aureus strain. Twenty-four hours later, the antibiotic-lock technique was started. All animals were randomized to receive daily isotonic sodium chloride solution, quinupristin-dalfopristin (Q/D), linezolid, vancomycin, or ciprofloxacin at the minimal bactericidal concentration (MBC) and at 1,024 microg/ml in a volume of 0.1 ml that filled the CVC. The main outcome measures were MICs and MBCs for both planktonic and adherent cells, quantitative culture of the catheters and surrounding venous tissues, and quantitative peripheral blood cultures. The killing activities of all antibiotics against the adherent bacteria were at least fourfold lower than those against freely growing cells, with the exception of Q/D, which showed comparable activities against both adherent and planktonic organisms. Overall, Q/D at 1,024 microg/ml produced the greatest reduction in the number of cells recovered from the catheters, while at the same concentration, Q/D and vancomycin demonstrated higher activities than ciprofloxacin or linezolid in reducing the number of organisms recovered from the blood cultures. This study points out that treatment outcome of device-related infections cannot be predicted by the results of a standard susceptibility test such as the MIC. Our findings suggest that the clinically used antibiotics cannot eradicate the CVC infection through the antibiotic-lock technique, even at a concentration of 1,024 microg/ml.

A chimeric peptide composed of a dermaseptin derivative and an RNA III-inhibiting peptide prevents graft-associated infections by antibiotic-resistant staphylococci

Staphylococcal bacteria are a prevalent cause of infections associated with foreign bodies and indwelling medical devices. Bacteria are capable of escaping antibiotic treatment through encapsulation into biofilms. RNA III-inhibiting peptide (RIP) is a heptapeptide that inhibits staphylococcal biofilm formation by obstructing quorum-sensing mechanisms. K(4)-S4(1-13)(a) is a 13-residue dermaseptin derivative (DD(13)) believed to kill bacteria via membrane disruption. We tested each of these peptides as well as a hybrid construct, DD(13)-RIP, for their ability to inhibit bacterial proliferation and suppress quorum sensing in vitro and for their efficacy in preventing staphylococcal infection in a rat graft infection model with methicillin-resistant Staphylococcus aureus (MRSA) or S. epidermidis (MRSE). In vitro, proliferation assays demonstrated that RIP had no inhibitory effect, while DD(13)-RIP and DD(13) were equally effective, and that the chimeric peptide but not DD(13) was slightly more effective than RIP in inhibiting RNA III synthesis, a regulatory RNA molecule important for staphylococcal pathogenesis. In vivo, the three peptides reduced graft-associated bacterial load in a dose-dependent manner, but the hybrid peptide was most potent in totally preventing staphylococcal infections at the lowest dose. In addition, each of the peptides acted synergistically with antibiotics. The data indicate that RIP and DD(13) act in synergy by attacking bacteria simultaneously by two different mechanisms. Such a chimeric peptide may be useful for coating medical devices to prevent drug-resistant staphylococcal infections.

Semaphorin 7A contributes to TGF-β-mediated liver fibrogenesis

Semaphorin7A (SEMA7A) is a membrane-anchored protein involved in immune and inflammatory responses, exerting an effect on pulmonary fibrosis. Thus, we aimed to investigate the role of SEMA7A in hepatic fibrosis. Liver injury was induced in vivo by carbon tetrachloride i.p. injection or bile duct ligation in wild-type and SEMA7A knockout (KO) mice. Human and mouse liver samples and primary mouse hepatic cell populations were used for Western blot analysis, quantitative real-time RT-PCR, and immunohistochemistry. SEMA7A is highly expressed in hepatic stellate cells (HSCs). The expression of SEMA7A and its receptor β1-integrin subunit increase during liver injury and in activated HSCs. Transforming growth factor β-stimulated HSCs showed increased expression of SEMA7A in a SMAD2/3-independent manner, leading to increased expression of fibrogenic and inflammation markers. This pattern was significantly blunted in SEMA7A KO HSCs. Overexpression of SEMA7A in HSCs showed increased fibrogenic and inflammation markers expression. In vivo, SEMA7A KO mice treated with carbon tetrachloride and bile duct ligation developed reduced fibrosis versus wild-type mice. Moreover, SEMA7A expression increased in liver samples of patients with fibrosis versus healthy controls. SEMA7A was expressed in the liver and was increased in the course of liver fibrosis, both in mice and in humans. SEMA7A was mainly expressed in HSCs with respect to other cell types in the liver and plays a critical role in regulating fibrosis.

Quorum sensing inhibitor FS3-coated vascular graft enhances daptomycin efficacy in a rat model of staphylococcal infection

The aim of the study was to investigate the efficacy of the quorum sensing inhibitor FS3 and daptomycin in preventing prosthesis biofilm in a rat model of staphylococcal vascular graft infection. Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses followed by topical inoculation with 2×10(7) colony-forming units of Staphylococcus aureus, strain Smith diffuse. The study included a control group, a contaminated group that did not receive any antibiotic prophylaxis and three contaminated groups that received: (i) intraperitoneal daptomycin, (ii) FS3-soacked graft, and (iii) daptomycin plus FS3-soaked graft, respectively. Each group included 15 animals. The infection burden was evaluated by using sonication and quantitative agar culture. Moreover, an in vitro binding-study was performed to quantify the how much FS3 was coated to the surface of the prosthesis. The in vitro studies showed, that minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for daptomycin were lower in presence of FS3. In in vivo studies, when tested alone, daptomycin and FS3 showed good efficacies. Their combination showed efficacies significantly higher than that of each single compound. Daptomycin is an important candidate for prevention of staphylococcal biofilm related infection and FS3 could serve as an interesting anti-staphylococcal antibiotic enhancer.

Citropin 1.1-treated central venous catheters improve the efficacy of hydrophobic antibiotics in the treatment of experimental staphylococcal catheter-related infection

An in vitro antibiotic susceptibility assay for Staphylococcus aureus biofilms developed on 96-well polystyrene tissue culture plates was performed to elucidate the activity of citropin 1.1, rifampin and minocycline. Efficacy studies were performed in a rat model of staphylococcal CVC infection. Silastic catheters were implanted into the superior cava. Twenty-four hours after implantation the catheters were filled with citropin 1.1 (10 microg/mL). Thirty minutes later the rats were challenged via the CVC with 1.0 x 10(6) CFU of S. aureus strain Smith diffuse. Administration of antibiotics into the CVC (the antibiotic lock technique) began 24 h later. The study included: one control group (no CVC infection), one contaminated group that did not receive any antibiotic prophylaxis, one contaminated group that received citropin 1.1-treated CVC, two contaminated groups that received citropin 1.1-treated CVC plus rifampin and minocycline at concentrations equal to MBCs for adherent cells and 1024 microg/mL in a volume of 0.1 mL that filled the CVC and two contaminated groups that received rifampin or minocycline at the same concentrations. All catheters were explanted 7 days after implantation. Main outcome measures were: minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), synergy studies, quantitative culture of the biofilm formed on the catheters and surrounding venous tissues, and quantitative peripheral blood cultures. MICs of conventional antibiotics against the bacteria in a biofilm were at least four-fold higher than against the freely growing planktonic cells. In contrast, when antibiotics were used on citropin 1.1 pre-treated cells they showed comparable activity against both biofilm and planktonic organisms. The in vivo studies show that when CVCs were pre-treated with citropin 1.1 or with a high dose of antibiotics, biofilm bacterial load was reduced from 10(7) to 10(3) CFU/mL and bacteremia reduced from 10(3) to 10(1) CFU/mL. When CVCs were treated both with citropin 1.1 and antibiotics, biofilm bacterial load was further reduced to 10(1) CFU/mL and bacteremia was not detected, suggesting 100% elimination of bacteremia and a log 6 reduction in biofilm load. Citropin 1.1 significantly reduces bacterial load and enhances the effect of hydrophobic antibiotics in the treatment of CVC-associated S. aureus infections.

ALPPS Procedure for Extended Liver Resections: A Single Centre Experience and a Systematic Review

Aim

To report a single-centre experience with the novel Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) technique and systematically review the related literature.

Methods

Since January 2013, patients with extended primary or secondary liver tumors whose future liver remnant (FLR) was considered too small to allow hepatic resection were prospectively assessed for the ALPPS procedure. A systematic literature search was performed using PubMed, Scopus and the Cochrane Library Central.

Results

Until July 2014 ALPPS was completed in 9 patients whose mean age was 60±8 years. Indications for surgical resection were metastases from colorectal cancer in 3 cases, perihilar cholangiocarcinoma in 3 cases, intrahepatic cholangiocarcinoma in 2 cases and hepatocellular carcinoma without chronic liver disease in 1 case. The calculated FLR volume was 289±122 mL (21.1±5.5%) before ALPPS-1 and 528±121 mL (32.2±5.7%) before ALLPS-2 (p<0.001). The increase in FLR between the two procedures was 96±47% (range: 24–160%, p<0.001). Additional interventions were performed in 4 cases: 3 patients underwent Roux-en-Y hepaticojejunostomy, and one case underwent wedge resection of a residual tumor in the FLR. The average time between the first and second step of the procedure was 10.8±2.9 days. The average hospital stay was 24.1±13.3 days. There was 1 postoperative death due to hepatic failure in the oldest patient of this series who had a perihilar cholangiocarcinoma and concomitant liver fibrosis; 11 complications occurred in 6 patients, 4 of whom had grade III or above disease. After a mean follow-up of 17.1±8.5 months, the overall survival was 89% at 3–6 and 12 months. The recurrence-free survival was 100%, 87.5% and 75% at 3-6-12 months respectively. The literature search yielded 148 articles, of which 22 articles published between 2012 and 2015 were included in this systematic review.

Conclusion

The ALPPS technique effectively increased the resectability of otherwise inoperable liver tumors. The postoperative morbidity in our series was high in accordance with the data from the systematic review. Age, liver fibrosis and presence of biliary stenting were predisposing factors for postoperative morbidity and mortality.