The "double-fired" gastro-jejunostomy as a form of improved efficiency during Whipple procedure.

BACKGROUND: Gastro-jejunostomy (GJ) after pylorus-resecting pancreatoduodenectomy (PD) is most commonly performed in a hand-sewn fashion. Intestinal stapled anastomosis are reported to be as effective as hand-sewn in terms of patency and risk of leakage in other indications. However, the use of a stapled gastro-jejunostomy hasn't been fully assessed in PD. The aim of the present technical report is to evaluate functional outcomes of stapled GJ during PD, its associated effect on operative time and related complications. METHODS: The institutional database for pancreatic duct adenocarcinoma (PDAC) was retrospectically reviewed. Pylorus resecting open PD without vascular or multivisceral resections were considered for the analysis. The incidence of clinically significant delayed gastric emptying (DGE from the International Stufy Group of Pancreatic Surgery (ISGPS) grade B and C), other complications, operative time and overall hospitalization were evaluated. RESULTS: Over a 10-years study period, 1182 PD for adenocarcinoma were performed and recorded in the database. 243 open Whipple procedures with no vascular and with no associated multivisceral resections were available and constituted the study population. Hand-sewn (HS) anastomosis was performed in 175 (72 %), stapled anastomosis (St) in 68 (28 %). No significant differences in baseline characteristics were observed between the two groups, with the exception of a higher rate of neoadjuvant chemotherapy in the HS group (74 % St vs. 86 % HS, p = 0.025). Intraoperatively, a significantly reduced median operative time in the St group was observed (248 min St vs. 370 mins HS, p < 0.001). Post-operatively, rates of clinically relevant delayed gastric emptying (7 % St vs. 14 % HS, p = 0.140), clinically relevant pancreatic fistula (10 % St, 15 % HS, p = 0.300), median length of stay (7 days for each group, p = 0.289), post-pancreatectomy hemorrhage (4.4 % St vs. 6.3 % HS, p = 0.415) and complication rate (22 % St vs. 34 % HS, p = 0.064) were similar between groups. However, readmission rates were significantly lower after St GJ (13.2 % St vs 29.7 % HS, p = 0.008). CONCLUSION: Our results indicate that a stapled GJ anastomosis during a standard Whipple procedure is non-inferior to a hand-sewn GJ, with a comparable rate of DGE and no increase of gastrointestinal related long term complications. Further, a stapled GJ anastomosis might be associated with reduced operative times.

Combined APRI/ALBI score to predict mortality after hepatic resection.

BACKGROUND: Aspartate aminotransferase/platelet ratio index (APRI) and albumin-bilirubin grade (ALBI) are validated prognostic indices implicated as predictors of postoperative liver dysfunction after hepatic resection. The aim of this study was to evaluate the relevance of the combined APRI/ALBI score for postoperative clinically meaningful outcomes. METHODS: Patients undergoing hepatectomy were included from the American College of Surgeons National Surgical Quality Improvement Program database. The association between APRI/ALBI score and postoperative grade C liver dysfunction, liver dysfunction-associated and overall 30-day mortality was assessed. RESULTS: A total of 12 055 patients undergoing hepatic resection from 2014 to 2017 with preoperative blood values and detailed 30-day postoperative outcomes were included (exploration cohort: January 2014 to December 2016; validation cohort: 2017). In the exploration cohort (8538 patients), the combination of both scores (APRI/ALBI) was significantly associated with postoperative grade C liver dysfunction, 30-day mortality, and liver dysfunction-associated 30-day mortality, and was superior to either score alone. The association with postoperative 30-day mortality was confirmed in multivariable analysis. A predictive model was generated using the exploration cohort. The predicted incidence of events closely followed the observed incidence in the validation cohort (3517 patients). Subgroup analyses of tumour types were used to generate disease-specific risk models to assess risk in different clinical scenarios. These findings informed development of a smartphone application (https://tellaprialbi.37binary.com). CONCLUSION: The predictive potential of the combined APRI/ALBI score for clinically relevant outcomes such as mortality was demonstrated. An evidence-based smartphone application will allow clinical translation and facilitation of risk assessment before hepatic resection using routine laboratory parameters.

The Combination of APRI and ALBI Facilitates Preoperative Risk Stratification for Patients Undergoing Liver Surgery After Neoadjuvant Chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy (NeoCTx) is performed for most patients with colorectal cancer liver metastases (CRCLM). However, chemotherapy-associated liver injury (CALI) has been associated with poor postoperative outcome. To date, however, no clinically applicable and noninvasive tool exists to assess CALI before liver resection. METHODS: Routine blood parameters were assessed in 339 patients before and after completion of NeoCTx and before surgery. The study assessed the prognostic potential of the aspartate aminotransferase (AST)-to-platelet ratio index (APRI), the albumin-bilirubin grade (ALBI), and their combinations. Furthermore, an independent multi-center validation cohort (n = 161) was included to confirm the findings concerning the prediction of postoperative outcome. RESULTS: Higher ALBI, APRI, and APRI + ALBI were found in patients with postoperative morbidity (P = 0.001, P = 0.064, P = 0.001, respectively), liver dysfunction (LD) (P = 0.009, P = 0.012, P < 0.001), or mortality (P = 0.037, P = 0.045, P = 0.016), and APRI + ALBI had the highest predictive potential for LD (area under the curve [AUC], 0.695). An increase in APRI + ALBI was observed during NeoCTx (P < 0.001). Patients with longer periods between NeoCTx and surgery showed a greater decrease in APRI + ALBI (P = 0.006) and a trend for decreased CALI at surgery. A cutoff for APRI + ALBI at - 2.46 before surgery was found to identify patients with CALI (P = 0.002) and patients at risk for a prolonged hospital stay (P = 0.001), intensive care (P < 0.001), morbidity (P < 0.001), LD (P < 0.001), and mortality (P = 0.021). Importantly, the study was able to confirm the predictive potential of APRI + ALBI for postoperative LD and mortality in a multicenter validation cohort. CONCLUSION: Determination of APRI + ALBI before surgery enables identification of high-risk patients for liver resection. The combined score seems to dynamically reflect CALI. Thus, APRI + ALBI could be a clinically relevant tool for optimizing timing of surgery in CRCLM patients after NeoCTx.

Mesh-augmented versus direct abdominal closure in patients undergoing open abdomen treatment.

BACKGROUND: Open abdomen (OA) may be required in patients with abdominal trauma, sepsis or compartment syndrome. Vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) is a widely used approach for temporary abdominal closure to close the abdominal wall. However, this method is associated with a high incidence of re-operations in short term and late sequelae such as incisional hernia. The current study aims to compare the results of surgical strategies of OA with versus without permanent mesh augmentation. METHODS: Patients with OA treatment undergoing vacuum-assisted wound closure and an intraperitoneal onlay mesh (VAC-IPOM) implantation were compared to VAWCM with direct fascial closure which represents the current standard of care. Outcomes of patients from two tertiary referral centers that performed the different strategies for abdominal closure after OA treatment were compared in univariate and multivariate regression analysis. RESULTS: A total of 139 patients were included in the study. Of these, 50 (36.0%) patients underwent VAC-IPOM and 89 (64.0%) patients VAWCM. VAC-IPOM was associated with reduced re-operations (adjusted incidence risk ratio 0.48 per 10-person days; CI 95% = 0.39-0.58, p < 0.001), reduced duration of stay on intensive care unit (ICU) [adjusted hazard ratio (aHR) 0.53; CI 95% = 0.36-0.79, p = 0.002] and reduced hospital stay (aHR 0.61; CI 95% = 0.040-0.94; p = 0.024). In-hospital mortality [22.5 vs 18.0%, risk difference - 4.5; confidence interval (CI) 95% = - 18.2 to 9.3; p = 0.665] and the incidence of intestinal fistula (18.0 vs 22.0%, risk difference 4.0; CI 95% = -10.0 to 18.0; p = 0.656) did not differ between the two groups. In Kaplan-Meier analysis, hernia-free survival was significantly increased after VAC-IPOM (p = 0.041). CONCLUSIONS: In patients undergoing OA treatment, intraperitoneal mesh augmentation is associated with a significantly decreased number of re-operations, duration of hospital and ICU stay and incidence of incisional hernias when compared to VAWCM.

Shaping the future of liver surgery: Implementation of experimental insights into liver regeneration.

BACKGROUND: While liver surgery has become a safe and feasible operation technique, the incidence of postoperative liver dysfunction still remains a central problem. Approximately 10% of patients undergoing liver resection were shown to develop liver dysfunction, which is associated with an increased risk of morbidity and mortality. Yet, to date there is no effective treatment option for postoperative liver dysfunction available. The development of postoperative liver dysfunction was linked to a disruption in the liver's potential to regenerate. Thus, it is importance to elucidate the underlying mechanisms of liver regeneration and to find potential therapeutic targets for the treatment of patients with postoperative liver dysfunction. METHODS: A review of the literature was carried out. RESULTS: We report on potential future interventions for improvement of liver regeneration after surgical resection. Moreover, we evaluate the benefits and drawbacks of hepatic progenitor cell therapy and hematopoietic stem cell therapy. However, the most significant improvement seems to come from molecular targets. Indeed, von Willebrand factor and its pharmacologic manipulation are among the most promising therapeutic targets to date. Furthermore, using the example of platelet-based therapy, we stress the potentially adverse effects of treatments for postoperative liver dysfunction. CONCLUSION: The present review reports on the newest advances in the field of regenerative science, but also underlines the need for more research in the field of postoperative liver regeneration, especially in regard to translational studies.

Plasma thrombospondin 1 as a predictor of postoperative liver dysfunction.

BACKGROUND: Liver regeneration following liver resection involves a complex interplay of growth factors and their antagonists. Thrombospondin 1 has recently been identified as a critical inhibitor of liver regeneration by the activation of transforming growth factor ß1 in mice, and preliminary data seem to confirm its relevance in humans. This study aimed to confirm these observations in an independent validation cohort. METHODS: Perioperative circulating levels of thrombospondin 1 were measured in patients undergoing liver resection between January 2012 and September 2013. Postoperative liver dysfunction was defined according to the International Study Group of Liver Surgery and classification of morbidity was based on the criteria by Dindo et al. RESULTS: In 85 patients (44 major and 41 minor liver resections), plasma levels of thrombospondin 1 increased 1 day after liver resection (mean 51·6 ng/ml before surgery and 68·3 ng/ml on postoperative day 1; P = 0·001). Circulating thrombospondin 1 concentration on the first postoperative day specifically predicted liver dysfunction (area under the receiver operating characteristic (ROC) curve 0·818, P = 0·003) and was confirmed as a significant predictor in multivariable analysis (Exp(B) 1·020, 95 per cent c.i. 1·005 to 1·035; P = 0·009). Patients with a high thrombospondin 1 concentration (over 80 ng/ml) on postoperative day 1 more frequently had postoperative liver dysfunction than those with a lower level (28 versus 2 per cent) and severe morbidity (44 versus 15 per cent), and their length of hospital stay was more than doubled (19·7 versus 9·9 days). CONCLUSION: Thrombospondin 1 may prove a helpful clinical marker to predict postoperative liver dysfunction as early as postoperative day 1.

Histological response, pattern of tumor destruction and clinical outcome after neoadjuvant chemotherapy including bevacizumab or cetuximab in patients undergoing liver resection for colorectal liver metastases.

AIM: We investigated whether the type of antibody [bevacizumab (bev) or cetuximab (cet)] added to neoadjuvant combination chemotherapy before curative liver resection was associated with histological response, the pattern of tumor destruction and clinical outcome in patients with colorectal liver metastases (CLM). METHODS: We investigated 138 patients with KRAS wild-type status (codon 12, 13 and 61) who received neoadjuvant chemotherapy including bev (n = 101) or cet (n = 37). The primary endpoint was histological response. Secondary endpoints were necrosis and fibrosis of metastases, radiological response, recurrence-free survival (RFS) and overall survival (OS). RESULTS: Histological response was not significantly different between the two groups (P = 0.19). A significantly higher fraction of patients in the bev group showed necrosis of the metastases of ≥ 50% (P < 0.001), while a higher fraction of patients in the cet group showed fibrosis of ≥ 40% (P = 0.030). Radiological response was not significantly different (P = 0.17). Median RFS was significantly shorter in the cet group in univariable analysis (HR 1.59 (95% CI 1.00, 2.51), P = 0.049), but this difference did not remain significant in multivariable analysis (P = 0.45). The 3-year OS rate was not significantly different (P = 0.73). CONCLUSIONS: The addition of bevacizumab to combination chemotherapy showed more necrosis but less fibrosis of metastases compared to cetuximab and a trend towards higher histological and radiological response and longer RFS. Further investigations of biological tumor characteristics are required to individualize treatment combinations.

Assessing the TP53 marker type in patients treated with or without neoadjuvant chemotherapy for resectable colorectal liver metastases: a p53 Research Group study.

The type of a biomarker - whether it is prognostic or predictive - is frequently not known, although such information is crucial for assessing the clinical value of a marker. In order to evaluate the type of marker TP53 is, we identified a cohort of 76 patients with colorectal liver metastases (CLM), homogeneously staged as resectable, who had been treated either with or without fluorouracil-based neoadjuvant chemotherapy. The TP53 genotype was assessed retrospectively from paraffin-embedded, diagnostic tumour biopsies using a standardised, p53 gene-specific sequencing protocol (mark53(®) kit). The overall median survival was 44.2 months, and the overall TP53 mutation frequency was 55%. A significant interaction was observed between chemotherapy and TP53 status (P = 0.045). To illustrate this effect, the 51 patients with and the 25 patients without neoadjuvant chemotherapy were described separately. In patients with neoadjuvant chemotherapy, mutated TP53 was significantly associated with poor survival (P = 0.0025), resulting in five-year survival rates of 22%, compared to 60% in patients with normal TP53. The hazard ratio was 3.12 (95% confidence intervals (CI): 1.46-6.95) to the disadvantage of TP53-mutated patients and 5.49 (P = 0.0001; 95% CI: 2.28-13.24) after adjustment for known prognostic factors. In patients treated with surgery alone, a mutated TP53 did not have a negative effect on survival (P = 0.54). A mutated TP53 status independently predicted survival disadvantage in CLM patients in the presence, but not in the absence, of neoadjuvant chemotherapy. Our data suggest that TP53 might be a pure predictive marker.

Neoadjuvant bevacizumab persistently inactivates VEGF at the time of surgery despite preoperative cessation.

BACKGROUND: When anti-VEGF (vascular endothelial growth factor) antibody bevacizumab is applied in neoadjuvant treatment of colorectal cancer patients with liver metastasis, 5-6 weeks between last bevacizumab dose and liver resection are currently recommended to avoid complications in wound and liver regeneration. In this context, we aimed to determine whether VEGF is inactivated by bevacizumab at the time of surgery. METHODS: Fifty colorectal cancer patients with liver metastases received neoadjuvant chemotherapy ± bevacizumab supplementation. The last dose of bevacizumab was administered 6 weeks before surgery. Plasma, subcutaneous and intraabdominal wound fluid were analysed for VEGF content before and after liver resection (day 1-3). Immunoprecipitation was applied to determine the amount of bevacizumab-bound VEGF. RESULTS: Bevacizumab-treated individuals showed no increase in perioperative complications. During the entire monitoring period, plasma VEGF was inactivated by bevacizumab. In wound fluid, VEGF was also completely bound by bevacizumab and was remarkably low compared with the control chemotherapy group. CONCLUSION: These data document that following a cessation time of 6 weeks, bevacizumab is fully active and blocks circulating and local VEGF at the time of liver resection. However, despite effective VEGF inactivation no increase in perioperative morbidity is recorded suggesting that VEGF activity is not essential in the immediate postoperative recovery period.

Thrombospondin-1: a unique marker to identify in vitro platelet activation when monitoring in vivo processes.

BACKGROUND: Measuring platelet activation in patients has become a potent method to investigate pathophysiological processes. However, the commonly applied markers are sensitive to detrimental influences by in vitro platelet activation during blood analysis. OBJECTIVES: Protein isoforms of platelet-derived thrombospondin-1 (TSP-1) were investigated for their potential to identify in vitro platelet activation when monitoring in vivo processes. METHODS: TSP-1 was determined in plasma, serum or supernatant of purified platelets by ELISA and immunoblotting and was compared with standard markers of platelet activation. A collective of 20 healthy individuals and 30 cancer patients was analyzed. RESULTS: While in vitro platelet degranulation led to a selective increase in the 200-kDa full-length molecule, an in vivo process involving platelet activation such as wound healing resulted in the predominant rise of the 140-kDa TSP-1 protein. The physiological ratio of circulating TSP-1 variants was determined and a cut-off level at 1.0 was defined to identify plasma samples with artificial in vitro platelet activation exceeding the cut-off level. In contrast, cancer patients known to frequently exhibit increased in vivo activation of platelets presented with a significantly decreased ratio of TSP-1 variants as compared with healthy volunteers. CONCLUSIONS: In comparison to standard platelet markers, TSP-1 constitutes a sensitive and stable parameter suited to monitor in vitro platelet activation. The analysis of TSP-1 protein isoforms further offers a valuable tool to reliably discriminate between in vitro and in vivo effects, to exclude variability introduced during blood processing and improve clinical monitoring.

Control of excision frequency of maize transposable element Ds in Petunia protoplasts.

The complete coding region of maize transposable element Ac and truncated but active derivatives of it were placed under the control of promoters of different strength and tested for the ability to excise transposable element Ds from a beta-glucuronidase reporter gene in a cotransfection assay in Petunia protoplasts. The highest excision values (5% of the protoplasts able to express the beta-glucuronidase gene in a control experiment) were observed with a truncated version of the Ac coding region under the control of the 2' promoter. The weak Ac promoter is sufficient to give rise to excision values not much lower than those found with much stronger promoters such as the 2' and nos promoters. A decrease in excision frequency was observed when translation of the Ac coding region was hindered by out-of-frame ATG codons in addition to the use of weak promoters. Increasing the level of Ac transposase thus does not seem to be sufficient to raise the level of Ds excision observed in this system and possibly also in maize. Therefore another factor limits the excision of Ds elements. Previously, it was reported that in tobacco cells the deletion of Ds sequence between base pairs 186 and 245 led to a decrease of the Ds excision frequency by the full-length but not by the truncated Ac product. In the Petunia assay system, however, deletion of these sequences decreased the excision rate with both the full length and the truncated Ac coding region. A cDNA construct was found similarly active as the corresponding genomic DNA.

Detection and abundance of mRNA and protein encoded by transposable element activator (Ac) in maize.

The 3.5 kb long mRNA of the maize transposable element Ac contains an open reading frame (ORFa) which encodes a polypeptide of 807 amino acids, the putative transposase of Ac. The Ac mRNA is a rare transcript: we now estimate the fraction of Ac mRNA in wx-m7::Ac seedlings to be 2-13 x 10(-5) of the polyA RNA. Assuming that maize cells contain similar amounts of polyA RNA as another monocot (0.16 pg/cell), this is equivalent to 1.5-10 transcripts in each cell. A protein with an apparent molecular weight of 112 kDa is detected, by five antisera directed against different segments of ORFa, exclusively in nuclear extracts from Ac-containing maize. This protein is most likely the full-length Ac ORFa protein. We estimate its concentration to be in the range of 3 x 10(-7) of the nuclear proteins, or about 1000 molecules per triploid endosperm cell containing one Ac element.

Mutational analysis of the N terminus of the protein of maize transposable element Ac.

Mutations of transposable element Ac were tested for their capability to excise themselves from their location autonomously, to be excised by an active Ac, or to act in trans in the excision of an Ac delta element. Removal of 101 amino acids from the N terminus of the Ac protein does not decrease excision. A cis-acting site between base pairs 186 and 207 is important for excision by the wild-type protein but is not necessary for excision by the truncated protein. Improvement of the sequence context of the first AUG does not have a significant effect. Mutations in a small open reading frame of Ac encoding a 102-amino acid protein do not visibly alter excision frequency.

Sequences near the termini are required for transposition of the maize transposon Ac in transgenic tobacco plants.

Deletion derivatives of the maize transposable element Activator (Ac) were constructed in vitro and inserted into a kanamycin resistance gene. These constructions were then introduced into tobacco protoplasts derived from plants previously transformed with Ac. The ability of each deletion derivative to excise was measured by whether or not kanamycin-resistant tobacco calli were recovered. This allowed us to determine the length of DNA present at each terminus that is required to respond to the products expressed by the Ac element present in the genome. We show that around 200 base pairs (bp) are required at both ends for excision to occur at wild-type levels. When between 100 and 200 bp were retained at one of the ends, reduced frequencies of excision were detected. With less than 100 bp remaining at either end, no excision was detected. In addition, we show that although similar lengths of DNA are required at each terminus, the termini are not interchangeable. The significance of these data is discussed with respect to the protein(s) which interact(s) with the termini of Ac.

Characterization of the maize transposable element Ac by internal deletions.

We have used the ability of Ac to transpose in tobacco to determine which Ac sequences are required for transposition, using a phenotypic assay for Ac excision from an NPTII gene in which excisions of Ac result in calli resistant to the antibiotic kanamycin (Baker et al., 1987). Here we show that deletion of the Ac DNA which encodes the untranslated leader of the Ac transcript does not prevent Ac excision. A deletion which removes 110 bp including the first 75 bp of long open reading frame prevents Ac excision in tobacco cells. However, it will excise in tobacco cells previously transformed with Ac indicating that deletion of the region prevents the synthesis of a product required for Ac excision. Deletion of the Ac sequences between bp 44 and bp 92 or from bp 75 to bp 181 abolishes, or strongly reduces, transposition in cells which are already transgenic for an active Ac element. This indicates that these deleted elements have lost sequences which are required for the transposon to respond to the transposase, when the enzyme is produced in trans. We also describe a tobacco strain transformed with a Ds element stably inserted wtihin an NPTII gene. This strain is Km and was retransformed with a construct containing the open reading frame (ORF) of the 3.5-kb Ac transcript expressed from a plant promoter. Expression of the cDNA construct promotes excision of the Ds element. These data suggest that the 3.5-kb transcript of Ac encodes the only Ac product required for transposition, i.e. the transposase function.

Overproduction of the protein encoded by the maize transposable element Ac in insect cells by a baculovirus vector.

The polypeptide encoded in the Activator (Ac) element of Zea mays L. has been expressed in Spodoptera frugiperda insect cells using plasmids which carry the strong polyhedrin promoter of the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). Recombinant AcNPVs with the Ac-cDNA integrated and under the control of the viral polyhedrin promoter have been isolated and their genomes have been partly characterized as to the location of the foreign DNA insert. Upon infection of S. frugiperda cells with the recombinant AcNPV, maize Ac element specific messenger RNAs, as well as a newly synthesized polypeptide with an apparent molecular weight of about 116 kDa, have been detected in extracts of recombinant infected cells. This polypeptide is absent from extracts of wild-type infected cells expressing the polyhedrin polypeptide which can be recognized by the presence of nuclear inclusion bodies. Recombinant infected cells lack this protein. The Ac specific polypeptide is detected by antisera, which have been raised against fusion proteins containing Ac sequences synthesized in Escherichia coli, both in immunoprecipitation and in Western blotting experiments. The Ac specific protein is a nuclear phosphoprotein and represents about 1%-2% of the newly synthesized protein.

Phenotypic assay for excision of the maize controlling element Ac in tobacco.

We describe a phenotypic assay designed to detect excision of the maize controlling element Ac from a selectable marker gene, neomycin phosphotransferase II (NPT II). An NPT II gene which expresses kanamycin resistance in tobacco cells, and contains a unique restriction enzyme site in the untranslated leader region, was constructed. Ac, or a defective Ac element (Ac big up tri, open), was inserted into the leader region of this gene. The transposon insertions inactivated the NPT II gene as determined by transient NPT II expression assays. The three plasmids were inserted into the T DNA of Agrobacterium tumefaciens Ti plasmid vectors, and transferred to tobacco protoplasts. The transformed protoplasts were selected with 100 or 200 microg/ml kanamycin. Protoplasts transformed by the NPT II gene interrupted by Ac formed 25% as many calli resistant to 100 or 200 microg/ml kanamycin as protoplasts transformed by the uninterrupted NPT II gene. Protoplasts transformed by the NPT II gene interrupted by Ac big up tri, open did not form any calli resistant to 200 microg/ml of kanamycin when transformed under similar conditions. Southern blot hybridization analyses of seven kanamycin-resistant calli or plants obtained after transformation by the NPT II gene interrupted by Ac revealed that in all cases Ac had excised, restoring the structure of the NPT II gene. This assay is therefore useful to monitor the activity of a transposable element such as Ac and to define the regions of this element involved in transposition activity.