Endoluminal radiofrequency ablation in patients with malignant biliary obstruction: a randomised trial.

BACKGROUND: Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique. DESIGN: In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280). RESULTS: A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups. CONCLUSION: A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction. TRIAL REGISTRATION NUMBER: NCT03166436.

Low-cost and prototype-friendly method for biocompatible encapsulation of implantable electronics with epoxy overmolding, hermetic feedthroughs and P3HT coating.

The research of novel implantable medical devices is one of the most attractive, yet complex areas in the biomedical field. The design and development of sufficiently small devices working in an in vivo environment is challenging but successful encapsulation of such devices is even more so. Industry-standard methods using glass and titanium are too expensive and tedious, and epoxy or silicone encapsulation is prone to water ingress with cable feedthroughs being the most frequent point of failure. This paper describes a universal and straightforward method for reliable encapsulation of circuit boards that achieves ISO10993 compliance. A two-part PVDF mold was machined using a conventional 3-axis machining center. Then, the circuit board with a hermetic feedthrough was placed in the mold and epoxy resin was injected into the mold under pressure to fill the cavity. Finally, the biocompatibility was further enhanced with an inert P3HT polymer coating which can be easily formulated into an ink. The biocompatibility of the encapsulants was assessed according to ISO10993. The endurance of the presented solution compared to silicone potting and epoxy potting was assessed by submersion in phosphate-buffered saline solution at 37 °C. The proposed method showed superior results to PDMS and simple epoxy potting.

Impact of Endoluminal Radiofrequency Ablation on Immunity in Pancreatic Cancer and Cholangiocarcinoma.

Radiofrequency ablation (RFA) is a mini-invasive loco-regional ablation technique that is increasingly being used as a palliative treatment for pancreatic cancer and cholangiocarcinoma. Ablation-triggered immune system stimulation has been proposed as a mechanism behind the systemic effects of RFA. The aim of our study was to investigate the immune response to endoluminal biliary RFA. Peripheral blood samples were collected from patients with pancreatic cancer and cholangiocarcinoma randomised to receive endoluminal biliary radiofrequency ablation + stent (19 patients) or stent only (21 patients). We observed an early increase in IL-6 levels and a delayed increase in CXCL1, CXCL5, and CXCL11 levels as well as an increase in CD8+ and NK cells. However, these changes were not specific to RFA treatment. Explicitly in response to RFA, we observed a delayed increase in serum CXCL1 levels and an early decrease in the number of anti-inflammatory CD206+ blood monocytes. Our study provides the first evidence of endoluminal biliary RFA-based regulation of the systemic immune response in patients with pancreatic cancer and cholangiocarcinoma. These changes were characterised by a general inflammatory response. RFA-specific activation of the adaptive immune system was not confirmed.

Fecal Microbial Transplantation in Critically Ill Patients-Structured Review and Perspectives.

The human gut microbiota consists of bacteria, archaea, fungi, and viruses. It is a dynamic ecosystem shaped by several factors that play an essential role in both healthy and diseased states of humans. A disturbance of the gut microbiota, also termed "dysbiosis", is associated with increased host susceptibility to a range of diseases. Because of splanchnic ischemia, exposure to antibiotics, and/or the underlying disease, critically ill patients loose 90% of the commensal organisms in their gut within hours after the insult. This is followed by a rapid overgrowth of potentially pathogenic and pro-inflammatory bacteria that alter metabolic, immune, and even neurocognitive functions and that turn the gut into the driver of systemic inflammation and multiorgan failure. Indeed, restoring healthy microbiota by means of fecal microbiota transplantation (FMT) in the critically ill is an attractive and plausible concept in intensive care. Nonetheless, available data from controlled studies are limited to probiotics and FMT for severe C. difficile infection or severe inflammatory bowel disease. Case series and observational trials have generated hypotheses that FMT might be feasible and safe in immunocompromised patients, refractory sepsis, or severe antibiotic-associated diarrhea in ICU. There is a burning need to test these hypotheses in randomized controlled trials powered for the determination of patient-centered outcomes.

Development of Radiofrequency Ablation Generator and Balloon-Based Catheter for Microendoluminal Thin-Layer Ablation Therapy Using the Rat Duodenum as a Model of Low-Impedance Tissue.

Radiofrequency ablation (RFA) is a routinely used, safe, and effective method for the tissue destruction. Often, in case of its application in malignant conditions, the extent of tissue destruction is insufficient due to the size of the target lesion, as well as due to the risk of heat-induced damage to the surrounding organs. Nevertheless, there are conditions requiring superficial precise-depth ablation with preservation of deeper layers. These are represented, for example, by mucosal resurfacing in case of Barrett's esophagus or treatment of recurrent mucosal bleeding in case of chronic radiation proctitis. Recently, new indications for intraluminal RFA use emerged, especially in the pancreatobiliary tract. In the case of intraductal use of RFA (e.g., biliary and pancreatic tract), there are currently available rigid and needle tip catheters. An expandable balloon-based RFA catheter suitable for use in such small-diameter tubular organs could be of benefit due to possible increase of contact between the probe and the target tissue; however, to prevent excessive tissue damage, a compatible generator suitable for low-impedance catheter/tissue is essential. This project aimed to develop a radiofrequency ablation generator and bipolar balloon-based catheter optimized for the application in the conditions of low-impedance tissue and (micro)endoluminal environment. Subsequent evaluation of biological effect in vivo was performed using duodenal mucosa in Wistar rat representing conditions of endoluminal radiofrequency ablation of low-impedance tissue. Experiments confirming the safety and feasibility of RFA with our prototype devices were conducted.

Construction of a Wireless-Enabled Endoscopically Implantable Sensor for pH Monitoring with Zero-Bias Schottky Diode-based Receiver.

Ambulatory pH monitoring of pathological reflux is an opportunity to observe the relationship between symptoms and exposure of the esophagus to acidic or non-acidic refluxate. This paper describes a method for the development, manufacturing, and implantation of a miniature wireless-enabled pH sensor. The sensor is designed to be implanted endoscopically with a single hemostatic clip. A fully passive rectenna-based receiver based on a zero-bias Schottky diode is also constructed and tested. To construct the device, a two-layer printed circuit board and off-the-shelf components were used. A miniature microcontroller with integrated analog peripherals is used as an analog front end for the ion-sensitive field-effect transistor (ISFET) sensor and to generate a digital signal which is transmitted with an amplitude shift keying transmitter chip. The device is powered by two primary alkaline cells. The implantable device has a total volume of 0.6 cm3 and a weight of 1.2 grams, and its performance was verified in an ex vivo model (porcine esophagus and stomach). Next, a small footprint passive rectenna-based receiver which can be easily integrated either into an external receiver or the implantable neurostimulator, was constructed and proven to receive the RF signal from the implant when in proximity (20 cm) to it. The small size of the sensor provides continuous pH monitoring with minimal obstruction of the esophagus. The sensor could be used in routine clinical practice for 24/96 h esophageal pH monitoring without the need to insert a nasal catheter. The "zero-power" nature of the receiver also enables the use of the sensor for automatic in-vivo calibration of miniature lower esophageal sphincter neurostimulation devices. An active sensor-based control enables the development of advanced algorithms to minimize the used energy to achieve a desirable clinical outcome. One of the examples of such an algorithm would be a closed-loop system for on-demand neurostimulation therapy of gastroesophageal reflux disease (GERD).

Obstructive Jaundice Secondary to Pancreatic Head Metastasis of Malignant Amelanotic Melanoma as the First Clinical Manifestation.

Malignant melanoma is commonly known for its high probability of metastasizing to distant organs. Metastases to gastrointestinal tract are well documented, but resulting jaundice is only scarcely seen. We present a case of histologically verified metastasis of amelanotic melanoma to the head of pancreas infiltrating the common bile duct and consequently causing obstructive jaundice which constituted its first clinical manifestation. Multidisciplinary approach is essential in patients with malignant melanoma since early detection of the melanoma or its metastases may improve patients' clinical outcome, especially owing to the use of targeted biological treatment without any delay.

Oncosurgery in older patients.

Population aging is one of the most significant health problems of the 21st century and has led to an increased need for surgery in elderly patients. Only chronological age should not be decisive when indicating patients for elective procedures. Other objective findings should be taken into account too. The complex geriatric examination is an optimized, detailed and accurately defined method, which leads to better postoperative outcomes in elderly patients. In everyday practice it is sufficient to evaluate the mental, physical and nutritional state of the patient. The goal of our study was to evaluate the perioperative morbidity and mortality of elderly patients undergoing hepatopancreatobiliary procedures. In our retrospective study we evaluated prospectively collected data of patients who underwent surgical procedures between 2015 and March 2019. In total 245 patients underwent pancreatic procedures and 156 underwent hepatic procedures. Morbidity and mortality were evaluated in the first 75 postoperative days and classified according the Clavien-Dindo classification. Our results show that when surgical procedures are correctly indicated in elderly patients, acceptable postoperative morbidity and mortality can be achieved. Since the year 2018 we have been actively using prerehabilitation in our center and it has led to improved postoperative outcomes in elderly and high-risk patients.

Searching for New Long-Lived Particles in Heavy-Ion Collisions at the LHC.

We show that heavy-ion collisions at the LHC provide a promising environment to search for new long-lived particles in well-motivated new physics scenarios. One advantage lies in the possibility to operate the main detectors with looser triggers, which can increase the number of observable events by orders of magnitude if the long-lived particles are produced with low transverse momentum. In addition, the absence of pileup in heavy-ion collisions can avoid systematic nuisances that will be present in future proton runs, such as the problem of vertex misidentification. Finally, there are new production mechanisms that are absent or inefficient in proton collisions. We show that the looser triggers alone can make searches in heavy-ion data competitive with proton data for the specific example of heavy neutrinos in the neutrino minimal standard model, produced in the decay of B mesons. Our results suggest that collisions of ions lighter than lead, which are currently under discussion in the heavy-ion community, are well motivated from the viewpoint of searches for new physics.

Comparison of Nonexposed Endoscopic Wall-Inversion Surgery with Endoscopic-Navigated Laparoscopic Wedge Resection for Gastric Submucosal Tumours: Results of a Two-Centre Study.

INTRODUCTION: The aim of this study was to compare the indications, operative details, and clinical outcomes of nonexposed endoscopic wall-inversion surgery with endoscopic-navigated laparoscopic wedge resection of gastric submucosal tumours. METHODS: Medical records were reviewed for patients who underwent nonexposed endoscopic wall-inversion surgery (NEWS) at the Faculty Hospital Kralovske Vinohrady and endoscopic-navigated laparoscopic wedge resection (LWR) at the Kepler University Hospital. Demographic, tumour, surgical, perioperative, and follow-up data were collected and compared. RESULTS: Eleven patients underwent NEWS and twelve patients underwent LWR. NEWS was associated with a longer operating time and more frequent suture line bleeding (3 cases in the NEWS group versus 1 case in the LWR group). Negative resection margins were achieved in all NEWS procedures and in 11 of the LWRs. The difference in size between the tumour and the resected specimen was smaller in the NEWS group. Length of hospitalisation was similar between the two groups (NEWS = 6.8 days, LWR = 6.5 days). Follow-up gastroscopies at 12 months postoperatively revealed no signs of recurrence in any of the patients. CONCLUSION: Nonexposed endoscopic wall-inversion surgery is a new technique for the treatment of gastric tumours. It allows for more precise resections with more frequent achievement of negative resection margins than LWRs. Additionally, it may allow for better preservation of gastric function and limit communication between the gastric lumen and peritoneal cavity. The longer operating time and more frequent complications associated with the NEWS reflects the limited experience with these new techniques.

Molecular pathology of cholangiocellular carcinomas.

Cholangiocellular carcinoma is a relatively rare malignant tumor, originating from cholangiocytes, with poor prognosis and late diagnosis. It is a malignancy with a variable biological etiology, numerous genetic and epigenetic changes. Its incidence in the Czech Republic is about 1.4 per 100,000 people per year. For good prognosis and long-term survival, early diagnosis with surgical treatment is important. In these cases, a 5-year survival rate is about 20-40 %. In the early diagnosis imaging methods and histopathological verification play an essential role, whereas laboratory oncomarkers are not yet sufficiently accurate. The same applies for genetic markers. This leads to the search of new molecular targets and the high effort in the introduction of cytological and molecular-biological methods with high specificity and sensitivity into routine practice. Current early diagnosis is based on the use of efficient imaging methods. The use of genetic testing, and especially knowledge of the molecular basis of this disease, will be of a great benefit. The observation of the association between the genetic pathways, IDH1, RAS-MAPK etc., and genetic mutations of genes, such as TP53, KRAS, SMAD4, BRAF, IDH1/2, may be significant. From the molecular point of view, it is also interesting to monitor oncogenic potential in HBV/HCV infection.

The role of single-operator cholangioscopy (SpyGlass) in the intraoperative diagnosis of intraductal borders of cholangiocarcinoma proliferation - pilot study.

Cholangiocarcinoma is a relatively rare, highly fatal neoplasm originating from the biliary epithelium. Its only potentially curative treatment option is a radical surgical resection. The aim of our work was to evaluate the feasibility and the safety of intraoperative ERCP and direct cholangioscopy (SpyGlass) to assess the intraductal border of cholangiocarcinoma proliferation. The study ran from November 2015 to January 2018. The group included patients with histologically verified cholangiocarcinoma and, based on available examinations, the resectability of the tumor was assessed by a multidisciplinary team. In cases of indicated surgical resection we peroperatively performed ERCP with cholangioscopy SpyGlass and "diaphanoscopy" in all patients. The resectability was assessed on the basis of these examinations and the peroperative surgical findings. The resection procedure itself was performed only in 2 out of the total of 14 patients, as other patients were indicated for the implantation of metallic SEMS within the ERCP procedure in the operating room instead. To validate the cholangioscopic findings, we used our own criteria based on both the Monaco and other criteria. We divided the findings according to the presence or absence of ulceration, prominent polyposis, pathological vascularization (4 types), pressure defect with a coagulum in the presence of previous stent implantation, papillomatous changes or discolorations of the mucosa. Out of the total number of 14 patients only two patients were indicated for resection and in both cases R0 resection was achieved. The remaining patients were intraoperatively indicated for palliative implantation of SEMS based on the same unresectable finding during cholangioscopy and laparotomy. We demonstrated the technical feasibility and safety of direct peroperative cholangioscopy. Our results show that direct perioperative cholangioscopy is one of the methods which can contribute to a more accurate determination of tumor spread margins.

Surgery for cholangiocarcinoma.

Cholangiocarcinoma represents the second most common primary liver malignancy. Despite it comprises only 3 % of all gastrointestinal malignancies, its incidence has been increasing recently. Cholangiocarcinomas are hepatobiliary cancers with features of cholangiocyte differentiation and from clinical point of view they are classified anatomically as intrahepatic or extrahepatic form. The only curative treatment with aim of long term and disease-free survival is surgery - liver resection or liver transplantation. Current progress in perioperative treatment and increased surgical skills has changed old treatment algorithms and widen number of patients suitable for curative treatment. On the other hand, surgical intervention is connected with not negligible morbidity and mortality. A rigorous knowledge of the disease extent and all prognostic factors is main condition for proper treatment decision.

The current role of radiotherapy and systemic therapy in the multidisciplinary treatment of cholangiocarcinoma.

Cholangiocarcinoma is a cancer with very poor prognosis. The only potentially curative approach is surgical resection of tumor. However, the rate of local and distant recurrence after radical surgery is still high. Benefit of adjuvant therapy is not clearly defined, nevertheless patients at high risk of recurrence are indicated to chemotherapy or chemoradiotherapy. Locally advanced, unresectable disease can also be treated with chemotherapy alone, or with her combination with radiotherapy. Required radiation doses are relatively high, therefore it is necessary to use highly conformal radiation therapy. Treatment of metastatic disease is currently based on systemic therapy, combination of gemcitabine and cisplatin as standard of care. Benefit of targeted molecular therapy is not clear at present, but ongoing research in genetic profiling of tumor may help to improve current clinical practice. Patients with cholangiocarcinoma have to be discussed during multidisciplinary team meetings.

Proximity-Induced Superconductivity in CdTe-HgTe Core-Shell Nanowires.

In this Letter we report on proximity superconductivity induced in CdTe-HgTe core-shell nanowires, a quasi-one-dimensional heterostructure of the topological insulator HgTe. We demonstrate a Josephson supercurrent in our nanowires contacted with superconducting Al leads. The observation of a sizable Ic Rn product, a positive excess current, and multiple Andreev reflections up to fourth order further indicate a high interface quality of the junctions.

Autonomous and Rechargeable Microneurostimulator Endoscopically Implantable into the Submucosa.

Gastric dysmotility can be a sign of common diseases such as longstanding diabetes mellitus. It is known that the application of high-frequency low-energetic stimulation can help to effectively moderate and alleviate the symptoms of gastric dysmotility. The goal of the research was the development of a miniature, endoscopically implantable device to a submucosal pocket. The implantable device is a fully customized electronic package which was specifically designed for the purpose of experiments in the submucosa. The device is equipped with a lithium-ion battery which can be recharged wirelessly by receiving an incident magnetic field from the charging/transmitting coil. The uplink communication is achieved in a MedRadio band at 432 MHz. The device was endoscopically inserted into the submucosal pocket of a live domestic pig used as an in vivo model, specifically in the stomach antrum. The experiment confirmed that the designed device can be implanted into the submucosa and is capable of bidirectional communication. The device can perform bipolar stimulation of muscle tissue.

Non-Exposure Endoscopic-Laparoscopic Cooperative Surgery for Stomach Tumors: First Experience from the Czech Republic.

BACKGROUND/AIMS: The aim of this study was to investigate the use of non-exposure endoscopic wall-inversion surgery (NEWS) and the combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET) in gastric tumors. METHODS: We reviewed all cases of NEWS and CLEAN-NET performed in the department of surgery of the Royal Vinohrady Teaching Hospital. RESULTS: Our department performed 12 gastric tumor resections (NEWS, n=10 and CLEAN-NET, n=2) between March 2016 and February 2017. The cases chosen for these resections included predominantly submucosal tumors with no signs of dissemination or local invasion and early gastric carcinomas (T1SM1 and T1M), where tumor location made it impossible to use endoscopic submucosal dissection. R0 resection margins were confirmed in all the cases. CONCLUSIONS: NEWS and CLEAN-NET allow en bloc non-exposed full-thickness gastric wall resection in a way that uses a "close first, cut later" approach to prevent seeding of the peritoneal cavity with tumor cells. These mini-invasive techniques combine laparoscopic and endoscopic techniques, and preserve the full function of the stomach.

Serum microRNA-196 and microRNA-200 in pancreatic ductal adenocarcinoma of patients with diabetes mellitus.

BACKGROUND/OBJECTIVES: Our aim was to compare expressions of 6 microRNAs (miRNAs) in patients with pancreatic ductal adenocarcinoma (PAC) and non-cancer patients, moreover according to the presence or absence of diabetes mellitus. METHODS: Expressions of miRNA-192, -196, -200, -21, -30 and -423 were measured in 77 patients with PAC and 64 non-cancer patients (34 patients with type 2 DM and 30 control persons). 60 patients with PAC (78%) had DM or prediabetes and it was of new-onset (less than 2 years before the cancer diagnosis) in 44 out of them. RESULTS: The expressions of all microRNAs were 1.4-3.7 times higher (significantly) in the PAC group compared to non-cancer patients. No difference was found between PAC diabetic and PAC non-diabetic patients. MicroRNA-200 was significantly higher in PAC patients with significant body weight loss against those without weight loss. Adding miRNA-196 and -200 to the current marker CA 19-9 improved the discriminative ability of the test (compared to CA 19-9 alone). CONCLUSION: MicroRNA-196 and -200 could be used as additional markers in PAC diagnosis.

[Effective bowel preparation before coloscopy - low-volume PEG in the divided dose regimen]. / Efektivní príprava streva pred koloskopií - nízkoobjemový PEG v deleném rezimu.

INTRODUCTION: The good and safe bowel cleansing is key to the success of coloscopy. The standard preparation involves 4 l polyethylene glycol (PEG). Now the combination of PEG and ascorbic acid (PEGA) of half the volume is available. Besides the type of product also the time factors which are not clarified, play a role during the bowel preparation. The aim of the study was to compare the efficiency and tolerance of both the agents and evaluate the effect of the time regimen of preparation. METHODS: 380 individuals were included in the evaluation in 4 cohorts which used 4 l PEG (Fortrans) in a single dose or split into 3 + 1 l and PEG + ascorbic acid (Moviprep) split into 1 + 1 l or 2 l one day before examination. RESULTS: There was no difference between the agents as to the quality of bowel preparation, when they were used in the same regimen. The bowel cleansing was better in both cases in the divided dose regimen (p < 0.001), and it was inversely proportional to the length of preparation (p = 0.003) and directly proportional to the length of time between the end of preparation and coloscopy (p < 0.001). PEGA was better tolerated (p < 0.028), regardless of the preparation regimen. CONCLUSION: PEG and PEGA are similarly efficient in the bowel preparation before coloscopy provided they are used in a similar regimen. The best results are reached when the preparation is divided into 2 days. PEGA is better tolerated than PEG, regardless of the used regimen. The quality of bowel cleansing is affected by the length of preparation (optimally up to 12 hours) and the time elapsed from the preparation until examination (up to 8 hours).