Kosuke Minaga

The clinical impact of ultrasound contrast agents in EUS: a systematic review according to the levels of evidence

BACKGROUND AND AIMS The use of contrast-harmonic EUS (CH-EUS) in routine clinical practice is increasing rapidly but is not yet standardized. We present the levels of evidence (LEs) found in the literature to put its clinical outcomes in the appropriate perspective. METHODS We conducted a systematic review of the available English-language articles. The LEs were stratified according to the Oxford Centre for Evidence-Based Medicine guidelines. RESULTS Overall, 210 articles were included and presented according to different pathologic conditions. For pancreatic solid neoplasms, the pooled sensitivity and specificity in the diagnosis of pancreatic carcinoma were very high (LE 1); quantitative analysis and guidance of FNA were reported as investigational research (LE 2-3). For pancreatic cystic lesions, the identification of neoplastic solid components as hyperenhanced lesions represented a promising application of CH-EUS (LE 2). For lymph nodes, CH-EUS increased the diagnostic yield of B-mode EUS for the detection of malignancy (LE 2). For submucosal tumors, CH-EUS seemed useful for differential diagnosis and risk stratification (LE 2-3). For other applications, differential diagnosis of gallbladder and vascular abnormalities by CH-EUS were reported (LE 2-3). CONCLUSIONS The LEs of CH-EUS in the literature have evolved from the initial descriptive studies to multicenter and prospective trials, and even meta-analyses. The differential diagnosis between benign and malignant lesions is the main field of application of CH-EUS. With regard to pancreatic solid neoplasms, the concomitant use of both CH-EUS and EUS-FNA may have additive value in increasing the overall accuracy by overcoming the false-negative results associated with each individual technique. Other applications are promising but still investigational.

Gankyrin induces STAT3 activation in tumor microenvironment and sorafenib resistance in hepatocellular carcinoma.

Most hepatocellular carcinomas (HCC) develop as a result of chronic liver inflammation. We have shown that the oncoprotein gankyrin is critical for inflammation‐induced tumorigenesis in the colon. Although the in vitro function of gankyrin is well known, its role in vivo remains to be elucidated. We investigated the effect of gankyrin in the tumor microenvironment of mice with liver parenchymal cell‐specific gankyrin ablation (Alb‐Cre;gankyrinf/f) and gankyrin deletion both in liver parenchymal and non‐parenchymal cells (Mx1‐Cre;gankyrinf/f). Gankyrin upregulates vascular endothelial growth factor expression in tumor cells. Gankyrin binds to Src homology 2 domain‐containing protein tyrosine phosphatase‐1 (SHP‐1), mainly expressed in liver non‐parenchymal cells, resulting in phosphorylation and activation of signal transducer and activator of transcription 3 (STAT3). Gankyrin deficiency in non‐parenchymal cells, but not in parenchymal cells, reduced STAT3 activity, interleukin (IL)‐6 production, and cancer stem cell marker (Bmi1 and epithelial cell adhesion molecule [EpCAM]) expression, leading to attenuated tumorigenic potential. Chronic inflammation enhances gankyrin expression in the human liver. Gankyrin expression in the tumor microenvironment is negatively correlated with progression‐free survival in patients undergoing sorafenib treatment for HCC. Thus, gankyrin appears to play a critical oncogenic function in tumor microenvironment and may be a potential target for developing therapeutic and preventive strategies against HCC.

Urgent endoscopic ultrasound-guided choledochoduodenostomy for acute obstructive suppurative cholangitis-induced sepsis

Acute obstructive suppurative cholangitis (AOSC) due to biliary lithiasis is a life-threatening condition that requires urgent biliary decompression. Although endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is the current gold standard for biliary decompression, it can sometimes be difficult because of failed biliary cannulation. In this retrospective case series, we describe three cases of successful biliary drainage with recovery from septic shock after urgent endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) was performed for AOSC due to biliary lithiasis. In all three cases, technical success in inserting the stents was achieved and the patients completely recovered from AOSC with sepsis in a few days after EUS-CDS. There were no procedure-related complications. When initial ERCP fails, EUS-CDS can be an effective life-saving endoscopic biliary decompression procedure that shortens the procedure time and prevents post-ERCP pancreatitis, particularly in patients with AOSC-induced sepsis.

New endoscopic ultrasonography techniques for pancreaticobiliary diseases

Endoscopic ultrasonography (EUS) is widely used to evaluate pancreaticobiliary diseases, especially pancreatic masses. EUS has a good ability to detect pancreatic masses, but it is not sufficient for the differential diagnosis of various types of lesions. In order to address the limitations of EUS, new techniques have been developed to improve the characterization of the lesions detected by EUS. EUS-guided fine needle aspiration (EUS-FNA) has been used for diagnosing pancreatic tumors. In order to improve the histological diagnostic yield, a EUS-FNA needle with a core trap has recently been developed. Contrast-enhanced harmonic EUS is a new imaging modality that uses an ultrasonographic contrast agent to visualize blood flow in fine vessels. This technique is useful in the diagnosis of pancreatic solid lesions and in confirming the presence of vascularity in mural nodules for cystic lesions. EUS elastography analyzes several different variables to measure tissue elasticity, color patterns, and strain ratio, using analytical techniques such as hue-histogram analysis, and artificial neural networks, which are useful for the diagnosis of chronic pancreatitis and pancreatic cancer.

Surgically resected needle tract seeding following endoscopic ultrasound-guided fine-needle aspiration in pancreatic cancer.

Needle tract seeding is a rare complication of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), with an estimated prevalence of 0.003%–0.009% [1]. We are aware of only six previous case reports in the published literature [2–7]. Herein, we report a case of needle tract seeding on the gastric wall after EUS-FNA of a pancreatic body adenocarcinoma. A 64-year-old woman with elevated serum CA19-9 levels was referred to our hospital. She underwent distal pancreatectomy 8months before. The pathological diagnosis was a T3N0M0 moderately differentiated tubular adenocarcinoma with a 20-mm maximum diameter and clear resection margins. A repeat computed tomography (CT) scan and magnetic resonance imaging showed no evidence of tumor recurrence; however, upper gastrointestinal endoscopy demonstrated a 12-mm submucosal tumor-like mass on the posterior gastric wall (Fig. 1a). Before surgery, she underwent EUS-FNA (three passes) through the posterior gastric wall using a 22gauge needle (EchoTip ProCore, Cook Medical, Limerick, Ireland) with a 10-mL syringe suction. The mass was located near the previous EUS-FNA puncture site where no masses had been detected during the initial preoperative examination. On EUS, this mass was heterogeneous and was mainly present in the third layer of the gastric wall (Fig. 1b). Positron emission tomography also showed abnormal accumulation in the proximal gastric body but with no abnormal uptake at the previous resection margin.

Chronic Fibro-Inflammatory Responses in Autoimmune Pancreatitis Depend on IFN-α and IL-33 Produced by Plasmacytoid Dendritic Cells

In previous studies, we found that human IgG4-related autoimmune pancreatitis (AIP) and murine AIP are driven by activation of plasmacytoid dendritic cells (pDCs) producing IFN-α. In the present studies we examined additional roles of pDC-related mechanisms in AIP pathogenesis, particularly those responsible for induction of fibrosis. We found that in murine AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid) not only the pancreatic infiltration of immune cells but also the development of fibrosis were markedly reduced by the depletion of pDCs or blockade of type I IFN signaling; moreover, such treatment was accompanied by a marked reduction of pancreatic expression of IL-33. Conversely, polyinosinic-polycytidylic acid–induced inflamed pancreatic tissue in murine AIP exhibited increased expression of type I IFNs and IL-33 (and downstream IL-33 cytokines such as IL-13 and TGF-β1). pDCs stimulated by type I IFN were the source of the IL-33 because purified populations of these cells isolated from the inflamed pancreas produced a large amount of IL-33 upon activation by TLR9 ligands, and such production was abrogated by the neutralization of type I IFN. The role of IL-33 in murine AIP pathogenesis was surprisingly important because blockade of IL-33 signaling by anti-ST2 Ab attenuated both pancreatic inflammation and accompanying fibrosis. Finally, whereas patients with both conventional pancreatitis and IgG4-related AIP exhibited increased numbers of acinar cells expressing IL-33, only the latter also exhibited pDCs producing this cytokine. These data thus suggest that pDCs producing IFN-α and IL-33 play a pivotal role in the chronic fibro-inflammatory responses underlying murine AIP and human IgG4-related AIP.

Predictors of pain response in patients undergoing endoscopic ultrasound-guided neurolysis for abdominal pain caused by pancreatic cancer

Background: Interventional endoscopic ultrasound (EUS)-guided procedures such as EUS-guided celiac ganglia neurolysis (EUS-CGN) and EUS-guided broad plexus neurolysis (EUS-BPN) were developed to treat abdominal cancer-associated pain; however, these procedures are not always effective. The aim of this study was to explore predictors of pain response in EUS-guided neurolysis for pancreatic cancer-associated pain. Methods: This was a retrospective analysis of prospectively collected data of 112 consecutive patients who underwent EUS-BPN in our institution. EUS-CGN was added in cases of visible celiac ganglia. The neurolytic-spread area was divided into six sections and evaluated by post-procedural computed tomography scanning. Pain intensity was assessed using a visual analog scale (VAS), and a decrease in VAS scores by ⩾3 points after neurolysis was considered a good pain response. Univariable and multivariable logistic regression analyses were performed to explore predictors of pain response at 1 and 4 weeks, and complications. Results: A good pain response was obtained in 77.7% and 67.9% of patients at 1 and 4 weeks, respectively. In the multivariable analysis of these patients, the combination method (EUS-BPN plus CGN) was a significant positive predictive factor at 1 week (odds ratio = 3.69, p = 0.017) and 4 weeks (odds ratio = 6.37, p = 0.043). The numbers of neurolytic/contrast spread areas (mean ± SD) were 4.98 ± 1.08 and 4.15 ± 1.12 in patients treated with the combination method and single method, respectively (p < 0.001). There was no significant predictor of complications. Conclusions: EUS-BPN in combination with EUS-CGN was a predictor of a good pain response in EUS-guided neurolysis for pancreatic cancer-related pain. The larger number of neurolytic/contrast spread areas may lead to better outcomes in patients receiving combination treatment.

Endoscopic ultrasonography‐guided choledochoduodenostomy using a newly designed laser‐cut metal stent: Feasibility study in a porcine model

Endoscopic ultrasonography (EUS)‐guided choledochoduodenostomy (EUS‐CDS) is increasingly used in the treatment of malignant distal biliary obstruction. Standardized use of this technique requires improvements in instruments, including more convenient and safer devices. The present study was designed to evaluate the resistance force to migration (RFM) of a newly designed laser‐cut metal stent and the feasibility of EUS‐CDS using this stent.

Evaluation of anti-migration properties of biliary covered self-expandable metal stents.

AIM To assess anti-migration potential of six biliary covered self-expandable metal stents (C-SEMSs) by using a newly designed phantom model. METHODS In the phantom model, the stent was placed in differently sized holes in a silicone wall and retracted with a retraction robot. Resistance force to migration (RFM) was measured by a force gauge on the stent end. Radial force (RF) was measured with a RF measurement machine. Measured flare structure variables were the outer diameter, height, and taper angle of the flare (ODF, HF, and TAF, respectively). Correlations between RFM and RF or flare variables were analyzed using a linear correlated model. RESULTS Out of the six stents, five stents were braided, the other was laser-cut. The RF and RFM of each stent were expressed as the average of five replicate measurements. For all six stents, RFM and RF decreased as the hole diameter increased. For all six stents, RFM and RF correlated strongly when the stent had not fully expanded. This correlation was not observed in the five braided stents excluding the laser cut stent. For all six stents, there was a strong correlation between RFM and TAF when the stent fully expanded. For the five braided stents, RFM after full stent expansion correlated strongly with all three stent flare structure variables (ODF, HF, and TAF). The laser-cut C-SEMS had higher RFMs than the braided C-SEMSs regardless of expansion state. CONCLUSION RF was an important anti-migration property when the C-SEMS did not fully expand. Once fully expanded, stent flare structure variables plays an important role in anti-migration.

Recent advances in endoscopic ultrasound‐guided biliary drainage

Endoscopic ultrasound‐guided biliary drainage (EUS‐BD) is increasingly used as an alternative in patients with biliary obstruction who fail standard endoscopic retrograde cholangiopancreatography (ERCP). The two major endoscopic approach routes for EUS‐BD are the transgastric intrahepatic and the transduodenal extrahepatic approaches. Biliary drainage can be achieved by three different methods, transluminal biliary stenting, transpapillary rendezvous technique, and antegrade biliary stenting. Choice of approach route and drainage method depends on individual anatomy, underlying disease, and location of the biliary stricture. Recent meta‐analyses have revealed that cumulative technical success and adverse event rates were 90–94% and 16–23%, respectively. Development of new dedicated devices for EUS‐BD would help refine the technical aspects and minimize the possibility of complications, making it a more promising procedure.