Preoperative imaging characteristics predict poor survival and inadequate resection for left-sided pancreatic adenocarcinoma: a multi-institutional analysis.

BACKGROUND: Optimal treatment of pancreatic ductal adenocarcinoma of the neck, body and tail (PDAC-NBT) necessitates R0 surgical resection. Preoperative radiographic identification of patients likely to achieve successful oncologic resection remains difficult. This study seeks to identify preoperative imaging characteristics predictive of non-R0 resections or impaired survival for PDAC-NBT. METHODS: Patients at five high-volume centers who underwent resection for PDAC-NBT were retrospectively analyzed. The most immediate preoperative cross-sectional scan was assessed along with outcome measures of overall survival and margin status. RESULTS: 330 patients were treated between 2001 and 2016. Margin status included 247 R0 (78.2%), 67 R1 (21.2%), and 2 R2 (0.6%). A non-R0 resection predicted worse survival (p = 0.0002). On preoperative imaging, patients with tumors greater than 20 mm, tumor attenuation greater than 70 Hounsfield units, or who demonstrated pancreatic atrophy and/or calcifications also had worse survival (p = 0.010, p = 0.036, p = 0.025 respectively). Patients with tumors interfacing with the splenic artery or vein or extending posteriorly achieved fewer R0 resections (p = 0.0006, p = 0.0004, p = 0.001, respectively). CONCLUSION: Preoperative cross-sectional imaging can identify tumor characteristics associated with poor survival and non-R0 resection. Further investigation is needed to identify the appropriate surgical and treatment modifications necessary to clinically benefit this subset of patients.

Gallstone Disease: Cholecystitis, Mirizzi Syndrome, Bouveret Syndrome, Gallstone Ileus.

Gallstone disease is a leading cause of morbidity in the United States and usually requires surgical or endoscopic interventions for diagnosis and/or treatment. Although gallstone disease is classically associated with the inflammatory sequela of cholecystitis, gallstones can also contribute to other clinical presentations such as gallstone ileus, Mirizzi syndrome, and Bouveret syndrome. This article explores the common-and uncommon-causes of surgical pathology owing to gallstones with an emphasis on clinical identification, diagnostics, and management options.

Sanguinarine inhibits pancreatic cancer stem cell characteristics by inducing oxidative stress and suppressing sonic hedgehog-Gli-Nanog pathway.

Sonic hedgehog pathway is highly activated in pancreatic cancer stem cells (CSC) which play crucial roles in cancer initiation, progression and metastasis. However, the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics is not well understood. The objectives of this study were to examine the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics. Sanguinarine inhibited cell proliferation and colony formation and induced apoptosis through oxidative damage. Sanguinarine inhibited self-renewal capacity of pancreatic CSCs isolated from human and KrasG12D mice. Furthermore, sanguinarine suppressed epithelial-mesenchymal transition (EMT) by up-regulating E-cadherin and inhibiting N-cadherin. Significant decrease in expression level of Snail, Slug and Zeb1 corroborated the suppression of EMT in sanguinarine treated pancreatic CSCS. The ability of sanguinarine to inhibit pluripotency maintaining factors and CSC markers suggest that sanguinarine can be an effective agent for inhibiting pancreatic cancer growth and development by targeting CSCs. Furthermore, sanguinarine inhibited Shh-Gli pathway leading to modulation of Gli target genes in pancreatic CSCs. Chromatin immunoprecipitation assay demonstrated that Nanog directly binds to promoters of Cdk2, Cdk6, FGF4, c-Myc and Oct4, and sanguinarine inhibits the binding of Nanog with these genes, suggesting the direct involvement of Nanog in cell cycle, pluripotency and self-renewal. To further investigate the role of Shh-Gli-Nanog pathway, we regulated Shh signaling either by Shh protein or Nanog overexpression. Enforced activation of Shh or overexpression of Nanog counteracted the inhibitory effects of sanguinarine on pancreatic CSC proliferation, suggesting the actions of sanguinarine are mediated, at least in part, through Shh-Gli-Nanog pathway. Our studies suggest that sanguinarine can be used for the treatment and/or prevention of pancreatic cancer by targeting CSCs.

What is a better predictor of clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD): postoperative day one drain amylase (POD1DA) or the fistula risk score (FRS)?

BACKGROUND: Both fistula risk score (FRS) and drain amylase in postoperative day 1 (POD1DA) have been promoted as tools to guide placement and removal of surgical drains following pancreaticoduodenectomy (PD). However, their individual utility has not been compared. METHODS: A consecutive cohort of PD patients from 2013 to 2015 were identified from a prospectively collected institutional database. Pearson correlation coefficients and receiver operating characteristic (ROC) curves were calculated for FRS (negligible/low vs. moderate/high) and POD1DA of 600 U/L and 5000 U/L as predictors of clinically relevant postoperative pancreatic fistula (CR-POPF). RESULTS: The incidence of CR-POPF was 27% in 216 patients. Sensitivity and specificity of FRS, POD1DA >600 U/L, and POD1DA >5000 U/L for predicting CR-POPF were 83% and 55%, 94% and 60%, 33% and 90%. The ROC area under the curve (AUC) for POD1DA >600 U/L (0.764) and FRS (0.749) were not significantly different (p = 0.713). However, POD1DA >5000 U/L (0.615) was significantly worse at predicting CR-POPF (p = 0.015). When FRS and POD1DA >600 U/L were combined; there was no improvement (p = 0.624). DISCUSSION: FRS and POD1DA are equally accurate in predicting CR-POPF. Patients with negligible/low FRS or POD1DA <600 U/L should be considered for drain removal.

WITHDRAWN: Classification and techniques of en bloc venous reconstruction for pancreaticoduodenectomy.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.hpb.2016.09.006. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Classification and techniques of en bloc venous reconstruction for pancreaticoduodenectomy.

BACKGROUND: Surgical resection is the only cure for hepato-pancreato-biliary (HPB) malignancy. In the era of multidisciplinary approaches and neoadjuvant therapies for locally advanced, borderline resectable tumors, the feasibility and efficacy of en bloc vascular resection has been validated across multiple studies. However, the variability of venous anatomy within the perihepatic and peri-portal regions necessitates familiarity with alternative resection and reconstruction techniques appropriate to the specific region of tumor invasion. METHODS: To organize these paradigms, the venous system has been divided into five zones: 1) hepatic hilum; 2) hepatoduodenal ligament; 3) portal vein/splenic vein confluence, which is further subdivided into right (3a) and left (3b); 4) infra-confluence; and 5) splenic vein. RESULTS: This study systematically analyzes the anatomic considerations and clinical scenarios specific to each zone to organize the necessary preparative maneuvers, surgical procedures, and vascular reconstruction techniques to achieve an R0 resection. The anatomic and tumor-specific factors which deem a specimen unresectable are also explored. Surgical videos demonstrating these techniques are presented. DISCUSSION: Preparation and familiarity with venous reconstruction maneuvers is essential for an oncologically effective operation, and can be safely achieved by utilizing this logical anatomic and procedural framework.

The bile acid receptor TGR5 does not interact with ß-arrestins or traffic to endosomes but transmits sustained signals from plasma membrane rafts.

TGR5 is a G protein-coupled receptor that mediates bile acid (BA) effects on energy balance, inflammation, digestion, and sensation. The mechanisms and spatiotemporal control of TGR5 signaling are poorly understood. We investigated TGR5 signaling and trafficking in transfected HEK293 cells and colonocytes (NCM460) that endogenously express TGR5. BAs (deoxycholic acid (DCA), taurolithocholic acid) and the selective agonists oleanolic acid and 3-(2-chlorophenyl)-N-(4-chlorophenyl)-N, 5-dimethylisoxazole-4-carboxamide stimulated cAMP formation but did not induce TGR5 endocytosis or recruitment of ß-arrestins, as assessed by confocal microscopy. DCA, taurolithocholic acid, and oleanolic acid did not stimulate TGR5 association with ß-arrestin 1/2 or G protein-coupled receptor kinase (GRK) 2/5/6, as determined by bioluminescence resonance energy transfer. 3-(2-chlorophenyl)-N-(4-chlorophenyl)-N, 5-dimethylisoxazole-4-carboxamide stimulated a low level of TGR5 interaction with ß-arrestin 2 and GRK2. DCA induced cAMP formation at the plasma membrane and cytosol, as determined using exchange factor directly regulated by cAMP (Epac2)-based reporters, but cAMP signals did not desensitize. AG1478, an inhibitor of epidermal growth factor receptor tyrosine kinase, the metalloprotease inhibitor batimastat, and methyl-ß-cyclodextrin and filipin, which block lipid raft formation, prevented DCA stimulation of ERK1/2. Bioluminescence resonance energy transfer analysis revealed TGR5 and EGFR interactions that were blocked by disruption of lipid rafts. DCA stimulated TGR5 redistribution to plasma membrane microdomains, as localized by immunogold electron microscopy. Thus, TGR5 does not interact with ß-arrestins, desensitize, or traffic to endosomes. TGR5 signals from plasma membrane rafts that facilitate EGFR interaction and transactivation. An understanding of the spatiotemporal control of TGR5 signaling provides insights into the actions of BAs and therapeutic TGR5 agonists/antagonists.

The TGR5 receptor mediates bile acid-induced itch and analgesia.

Patients with cholestatic disease exhibit pruritus and analgesia, but the mechanisms underlying these symptoms are unknown. We report that bile acids, which are elevated in the circulation and tissues during cholestasis, cause itch and analgesia by activating the GPCR TGR5. TGR5 was detected in peptidergic neurons of mouse dorsal root ganglia and spinal cord that transmit itch and pain, and in dermal macrophages that contain opioids. Bile acids and a TGR5-selective agonist induced hyperexcitability of dorsal root ganglia neurons and stimulated the release of the itch and analgesia transmitters gastrin-releasing peptide and leucine-enkephalin. Intradermal injection of bile acids and a TGR5-selective agonist stimulated scratching behavior by gastrin-releasing peptide- and opioid-dependent mechanisms in mice. Scratching was attenuated in Tgr5-KO mice but exacerbated in Tgr5-Tg mice (overexpressing mouse TGR5), which exhibited spontaneous pruritus. Intraplantar and intrathecal injection of bile acids caused analgesia to mechanical stimulation of the paw by an opioid-dependent mechanism. Both peripheral and central mechanisms of analgesia were absent from Tgr5-KO mice. Thus, bile acids activate TGR5 on sensory nerves, stimulating the release of neuropeptides in the spinal cord that transmit itch and analgesia. These mechanisms could contribute to pruritus and painless jaundice that occur during cholestatic liver diseases.

The receptor TGR5 mediates the prokinetic actions of intestinal bile acids and is required for normal defecation in mice.

BACKGROUND & AIMS: Abnormal delivery of bile acids (BAs) to the colon as a result of disease or therapy causes constipation or diarrhea by unknown mechanisms. The G protein-coupled BA receptor TGR5 (or GPBAR1) is expressed by enteric neurons and endocrine cells, which regulate motility and secretion. METHODS: We analyzed gastrointestinal and colon transit, as well as defecation frequency and water content, in wild-type, knockout, and transgenic mice (trg5-wt, tgr5-ko, and tgr5-tg, respectively). We analyzed colon tissues for contractility, peristalsis, and transmitter release. RESULTS: Deoxycholic acid inhibited contractility of colonic longitudinal muscle from tgr5-wt but not tgr5-ko mice. Application of deoxycholic acid, lithocholic acid, or oleanolic acid (a selective agonist of TGR5) to the mucosa of tgr5-wt mice caused oral contraction and caudal relaxation, indicating peristalsis. BAs stimulated release of the peristaltic transmitters 5-hydroxytryptamine and calcitonin gene-related peptide; antagonists of these transmitters suppressed BA-induced peristalsis, consistent with localization of TGR5 to enterochromaffin cells and intrinsic primary afferent neurons. tgr5-ko mice did not undergo peristalsis or transmitter release in response to BAs. Mechanically induced peristalsis and transmitter release were not affected by deletion of tgr5. Whole-gut transit was 1.4-fold slower in tgr5-ko than tgr5-wt or tgr5-tg mice, whereas colonic transit was 2.2-fold faster in tgr5-tg mice. Defecation frequency was reduced 2.6-fold in tgr5-ko and increased 1.4-fold in tgr5-tg mice compared with tgr5-wt mice. Water content in stool was lower (37%) in tgr5-ko than tgr5-tg (58%) or tgr5-wt mice (62%). CONCLUSIONS: The receptor TGR5 mediates the effects of BAs on colonic motility, and deficiency of TGR5 causes constipation in mice. These findings might mediate the long-known laxative properties of BAs, and TGR5 might be a therapeutic target for digestive diseases.

Localization of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1) in human gastrointestinal tract.

Calcitonin gene-related peptide (CGRP) exerts its diverse effects on vasodilation, nociception, secretion, and motor function through a heterodimeric receptor comprising of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1). Despite the importance of CLR·RAMP1 in human disease, little is known about its distribution in the human gastrointestinal (GI) tract, where it participates in inflammation and pain. In this study, we determined that CLR and RAMP1 mRNAs are expressed in normal human stomach, ileum and colon by RT-PCR. We next characterized antibodies that we generated to rat CLR and RAMP1 in transfected HEK cells. Having characterized these antibodies in vitro, we then localized CLR-, RAMP1-, CGRP- and intermedin-immunoreactivity (IMD-IR) in various human GI segments. In the stomach, nerve bundles in the myenteric plexus and nerve fibers throughout the circular and longitudinal muscle had prominent CLR-IR. In the proximal colon and ileum, CLR was found in nerve varicosities of the myenteric plexus and surrounding submucosal neurons. Interestingly, CGRP expressing fibers did not co-localize, but were in close proximity to CLR. However, CLR and RAMP1, the two subunits of a functional CGRP receptor were clearly localized in myenteric plexus, where they may form functional cell-surface receptors. IMD, another member of calcitonin peptide family was also found in close proximity to CLR, and like CGRP, did not co-localize with either CLR or RAMP1 receptors. Thus, CGRP and IMD appear to be released locally, where they can mediate their effect on their receptors regulating diverse functions such as inflammation, pain and motility.

Impairment of central leptin-mediated PI3K signaling manifested as hepatic steatosis independent of hyperphagia and obesity.

Hepatic steatosis is generally thought to develop via peripheral mechanisms associated with obesity. We show that chronic central infusion of leptin suppresses hepatic lipogenic gene expression and reduces triglyceride content via stimulation of hepatic sympathetic activity. This leptin function is independent of feeding and body weight but requires phosphatidylinositol 3-kinase (PI3K) signaling. Attenuation of leptin-induced PI3K signaling, brought about by transgenic expression of phosphatase and tensin homolog (PTEN) in leptin receptor neurons, leads to decreased hepatic sympathetic tone and increased triglyceride levels without affecting adiposity or hepatic insulin signaling. Central leptin's effects on hepatic norepinephrine levels and triglyceride content are blunted in these mutant mice. Simultaneous downregulation of PI3K and signal transducer and activator of transcription-3 (Stat3) in leptin receptor neurons does not exacerbate obesity but causes more severe hepatic steatosis. Together, our results indicate that central cellular leptin resistance in PI3K signaling manifests as hepatic steatosis without causing obesity.

Laparoscopic treatment of liver tumours using a two-needle probe bipolar radiofrequency ablation device.

BACKGROUND: Many hepatobiliary centres are increasingly utilizing thermocoagulative devices such as bipolar-radiofrequency ablation (B-RFA). Compared with monopolar-radiofrequency ablation (M-RFA), B-RFA does not require grounding pads, thereby avoiding dermal burn injuries, and does not position probes directly into the tumour but rather on the perimeter. Additionally, B-RFA can precoagulate parenchyma to assist in hepatic resection. Herein, we report our early experience using B-RFA. METHODS: A retrospective review identified 68 patients who underwent M-RFA or B-RFA between June 2004 and September 2010 in an academic centre. Peri-operative metrics were analysed. RESULTS: M-RFA was used to treat 30 patients, whereas B-RFA was used for 17 patients. There were no differences in peri-operative metrics, survival or disease recurrence between M-RFA and B-RFA. Seventeen additional patients underwent B-RFA precoagulation during laparoscopic resection (segmentectomy in eleven patients and multi-segmental resection in six patients). Four patients with multifocal disease underwent procedures that combined B-RFA with resection. CONCLUSIONS: The early experience utilizing B-RFA demonstrates equivalency to M-RFA with respect to peri-operative metrics and survival. Moreover, B-RFA can be utilized to precoagulate tissue during a planned resection, making it not only a useful tool for tumour therapy but also a useful adjunct during surgical resections.

Hepatic surgery at a VA tertiary medical center: lessons learned.

BACKGROUND: The development of a hepatic surgery center within a US Department of Veterans Affairs hospital is dependent on proper training and institutional support, which can translate into low operative morbidity and mortality rates. METHODS: Patients who underwent hepatic procedures between 2003 and 2009 were retrospectively reviewed. A subset analysis of laparoscopic liver resections for patients with hepatocellular cancer (HCC) was performed. One hundred twenty-six patients underwent 130 hepatic procedures, 65% of which were hepatic resections. Ninety-seven percent of cases were for malignant disease, including HCC (70%). RESULTS: The morbidity and mortality rates were 15.5% and 2.4%, respectively. For patients with HCC there was no difference in operative outcomes or overall survival when procedures were performed laparoscopically. CONCLUSIONS: A Veterans Affairs (VA) hospital specializing in hepatic surgery can achieve low complication rates comparable with those of high-volume centers. The numbers of patient referrals and hepatic resections and the proportion of laparoscopic operations increased after the creation of a dedicated hepatic surgery center within a single VA hospital.