Endoscopic Ultrasound Guided Shear Wave Elastography Is Safe With High Feasibility and Reproducibility When Used in the Pancreas: Findings From a Prospective Cohort.

OBJECTIVES: The aim of this study was to assess the safety, feasibility, and reproducibility of endoscopic ultrasound shear wave elastography (EUS-SWE) in the pancreas. METHODS: This is a prospective registry of consecutive patients undergoing clinically indicated EUS. Ten readings of SWE velocities (Vs [distance/time, m/s]) were obtained in the head (HOP), body, and tail of pancreas to quantify tissue stiffness. Each Vs score was accompanied by a reliability measurement VsN (%) with VsN >50% considered reliable. Safety was evaluated by perioperative complications rate. Feasibility was determined by technical success of obtaining measurements. Reproducibility was evaluated using intraclass correlation coefficient analysis. RESULTS: Total of 3320 EUS-SWE measurements were performed on 117 patients without perioperative complications. Measurement success rate was 100% across all locations. Reliable measurements were more common in the HOP (953/1120 [85.1%]) followed by body (853/1130 [75.5%]) and tail of pancreas (687/1070 [64.2%]) (P < 0.001). The analysis showed good reproducibility in all locations (intraclass correlation coefficient range, 0.80-0.89). CONCLUSIONS: Endoscopic ultrasound-SWE is safe, has 100% technical success rate, and is highly reproducible when used in the pancreas. Our study suggests that SWE measurements in the HOP offer the highest reliability, likely because of large study area and less respiratory artifact.

Rising Incidence of Non-Cardia Gastric Cancer among Young Women in the United States, 2000-2018: A Time-Trend Analysis Using the USCS Database.

INTRODUCTION: Although the global incidence of non-cardia gastric cancer (NCGC) is decreasing, there are limited data on sex-specific incidence in the United States. This study aimed to investigate time trends of NCGC from the SEER database to externally validate findings in a SEER-independent national database, and to further assess trends among subpopulations. METHODS: Age-adjusted incidence rates of NCGC were obtained from the SEER database from 2000 to 2018. We used joinpoint models to calculate average annual percentage change (AAPC) to determine sex-specific trends among older (≥55 years) and younger adults (15-54 years). Using the same methodology, findings were then externally validated using SEER-independent data from the National Program of Cancer Registries (NPCR). Stratified analyses by race, histopathology, and staging at diagnosis were also conducted in younger adults. RESULTS: Overall, there were 169,828 diagnoses of NCGC from both independent databases during the period 2000-2018. In SEER, among those <55 years, incidence increased at a higher rate in women (AAPC = 3.22%, p < 0.01) than men (AAPC = 1.51%, p = 0.03), with non-parallel trends (p = 0.02), while a decreasing trend was seen in both men (AAPC = -2.16%, p < 0.01) and women (AAPC = -1.37%, p < 0.01) of the ≥55 years group. Validation analysis of the SEER-independent NPCR database from 2001 to 2018 showed similar findings. Further stratified analyses showed that incidence is disproportionately increasing in young non-Hispanic White women [AAPC = 2.28%, p < 0.01] while remaining stable in their counterpart men [AAPC = 0.58%, p = 0.24] with non-parallel trends (p = 0.04). This pattern was not observed in other race groups. CONCLUSION: NCGC incidence has been increasing at a greater rate in younger women compared to counterpart men. This disproportionate increase was mainly seen in young non-Hispanic White women. Future studies should investigate the etiologies of these trends.

Increasing Pancreatic Cancer Incidence in Young Women in the United States: A Population-Based Time-Trend Analysis, 2001-2018.

BACKGROUND & AIMS: Previous studies have shown an increasing incidence of pancreatic cancer (PC), especially in younger women; however, this has not been externally validated. In addition, there are limited data about contributing factors to this trend. We report age and sex-specific time-trend analysis of PC age-adjusted incidence rates (aIRs) using the National Program of Cancer Registries database without Surveillance Epidemiology and End Results data. METHODS: PC aIR, mortality rates, annual percentage change, and average annual percentage change (AAPC) were calculated and assessed for parallelism and identicalness. Age-specific analyses were conducted in older (≥55 years) and younger (<55 years) adults. PC incidence based on demographics, tumor characteristics, and mortality were evaluated in younger adults. RESULTS: A total of 454,611 patients were diagnosed with PC between 2001 and 2018 with significantly increasing aIR in women (AAPC = 1.27%) and men (AAPC = 1.14%) without a difference (P = .37). Similar results were seen in older adults. However, in younger adults (53,051 cases; 42.9% women), women experienced a greater increase in aIR than men (AAPCs = 2.36%, P < .001 vs 0.62%, P = 0.62) with nonparallel trends (P < .001) and AAPC difference of 1.74% (P < .001). This AAPC difference appears to be due to rising aIR in Blacks (2.23%; P < .001), adenocarcinoma histopathologic subtype (0.89%; P = .003), and location in the head-of-pancreas (1.64%; P < .001). PC mortality was found to be unchanged in women but decreasing in counterpart men (AAPC difference = 0.54%; P = .001). CONCLUSION: Using nationwide data, covering ≈64.5% of the U.S. population, we externally validate a rapidly increasing aIR of PC in younger women. There was a big separation of the incidence trend between women and men aged 15-34 years between 2001 and 2018 (>200% difference), and it did not show slowing down.

Pancreatic Cancer Incidence Trends by Race, Ethnicity, Age and Sex in the United States: A Population-Based Study, 2000-2018.

BACKGROUND AND AIMS: Pancreatic cancer (PC) incidence is increasing at a greater rate in young women compared to young men. We performed a race- and ethnicity-specific evaluation of incidence trends in subgroups stratified by age and sex to investigate the association of race and ethnicity with these trends. METHODS: Age-adjusted PC incidence rates (IR) from the years 2000 to 2018 were obtained from the SEER 21 database. Non-Hispanic White (White), Non-Hispanic Black (Black) and Hispanic patients were included. Age categories included older (ages ≥ 55) and younger (ages < 55) adults. Time-trends were described as annual percentage change (APC) and average APC (AAPC). RESULTS: Younger White [AAPC difference = 0.73, p = 0.01)], Black [AAPC difference = 1.96, p = 0.01)] and Hispanic [AAPC difference = 1.55, p = 0.011)] women experienced a greater rate of increase in IR compared to their counterpart men. Younger Hispanic women experienced a greater rate of increase in IR compared to younger Black women [AAPC difference = -1.28, p = 0.028)] and younger White women [AAPC difference = -1.35, p = 0.011)]. CONCLUSION: Younger women of all races and ethnicities experienced a greater rate of increase in PC IR compared to their counterpart men; however, younger Hispanic and Black women experienced a disproportionately greater increase. Hispanic women experienced a greater rate of increase in IR compared to younger Black and White women.

Phase transition of individual anatase TiO2 microcrystals with large percentage of (001) facets: a Raman mapping and SEM study.

TiO2 has been extensively studied in many fields including photocatalysis, electrochemistry, optics, etc. Understanding the mechanism of the anatase-rutile phase transition (ART) process is critical for the design of TiO2-based high-activity photocatalysts and tuning its properties for other applications. In this work, the ART process using individual anatase micro-particles with a large percentage of (001) facets was monitored and studied. Phase concentration evolution obtained via Raman microscopy was correlated with the morphological evolution observed in scanning electron microscope (SEM) images. The ART of anatase microcrystals is dominated by surface nucleation and growth, but the ART processes of individual anatase particles are distinctive and depend on the various rutile nucleation sites. Two types of transformation pathways are observed. In one type of ART pathway, the rutile phase nucleated at a corner of an anatase microcrystal and grew in one direction along the edge of the crystal firstly followed by propagation over the rest of the microcrystal in the orthogonal direction on the surface and to the bulk of the crystal. The kinetics of the ART follows the first-order model with two distinct rate constants. The fast reaction rate is from the surface nucleation and growth, and the slow rate is from the bulk nucleation and growth. In the other type of ART pathway, multiple rutile nucleation sites formed simultaneously on different edges and corners of the microcrystal. The rutile phase spread over the whole crystal from these nucleation sites with a small contribution of bulk nucleation. Our study on the ART of individual micro-sized crystals bridges the material gap between bulk crystals and nano-sized TiO2 particles. The anatase/rutile co-existing particle will provide a perfect platform to study the synergistic effect between the anatase phase and the rutile phase in their catalytic performances.

Impact of COVID-19 infection and vaccination in pancreatobiliary IgG4-related disease patients: An international multicenter study.

BACKGROUND AND AIM: Dedicated studies evaluating the impact of COVID-19 on outcomes of pancreatobiliary IgG4 related disease (IgG4-RD) patients are scarce. Whether COVID-19 infection or vaccination would trigger IgG4-RD exacerbation remains unknown. METHODS: Pancreatobiliary IgG4-RD patients ≥ 18 years old with active follow-up since January 2020 from nine referral centers in Asia, Europe, and North America were included in this multicenter retrospective study. Outcome measures include incidence and severity of COVID-19 infection, IgG4-RD disease activity and treatment status, interruption of indicated IgG4-RD treatment. Prospective data on COVID-19 vaccination status and new COVID-19 infection during the Omicron outbreak were also retrieved in the Hong Kong cohort. RESULTS: Of the 124 pancreatobiliary IgG4-RD patients, 25.0% had active IgG4-RD, 71.0% were on immunosuppressive therapies and 80.6% had ≥ 1 risk factor for severe COVID. In 2020 (pre-vaccination period), two patients (1.6%) had COVID-19 infection (one requiring ICU admission), and 7.2% of patients had interruptions in indicated immunosuppressive treatment for IgG4-RD. Despite a high vaccination rate (85.0%), COVID-19 infection rate has increased to 20.0% during Omicron outbreak in the Hong Kong cohort. A trend towards higher COVID-19 infection rate was noted in the non-fully vaccinated/unvaccinated group (17.6% vs 33.3%, P = 0.376). No IgG4-RD exacerbation following COVID-19 vaccination or infection was observed. CONCLUSION: While a low COVID-19 infection rate with no mortality was observed in pancreatobiliary IgG4-RD patients in the pre-vaccination period of COVID-19, infection rate has increased during the Omicron outbreak despite a high vaccination rate. No IgG4-RD exacerbation after COVID-19 infection or vaccination was observed.

Quality improvement project on the development of a management algorithm for iatrogenic perforations and the long-term impact on physician knowledge.

Background and study aims Acute iatrogenic endoscopic perforations (AIEPs) can have high morbidity and mortality, especially colonic perforations. Knowledge of diagnosis and AIEP management can improve patient care. The aims of this study were to: develop an evidence-based AIEP management algorithm; study its short-term and long-term impact on physician knowledge; and evaluate physician knowledge using hypothetical clinical scenarios. Methods An institutional AIEP management algorithm was created using the most current recommendations from the American Society for Gastrointestinal Endoscopy and the European Society of Gastrointestinal Endoscopy. Input from advanced endoscopists, nurses, and anesthesiologists was also obtained. We assessed change in physician knowledge using a 10-item questionnaire before (pretest), a standardized one-page AIEP educational material and algorithm immediately after (post-test) to test short-term retention, and 6 months later (6-month reassessment) to test long-term retention. With the 6-month reassessment, two clinical scenarios based on real AIEP were presented to evaluate application of knowledge. Results Twenty-eight subjects (8 gastroenterology fellows and 20 practicing gastroenterologists) participated in the assessments. Pretest and immediate post-test accuracies were 75 % and 95 % ( P  < 0.01), respectively. Six-month reassessment accuracies were 83.6 %, significantly worse compared to post-test accuracies ( P  < 0.05), but significantly improved compared to pretest accuracies ( P  < 0.05). Accuracies for clinical scenarios #1 and #2 were 67.5 % and 60.3 %, respectively. Fellows had similar accuracies when compared to practicing gastroenterologists. Conclusions Using standardized methodology and a multidisciplinary approach, an AIEP management algorithm was created to improve patient care and alleviate physician and staff stress. In addition, we showed that a one-page educational document on perforations can significantly improve short-term and long-term physician knowledge, although periodic reeducation is needed.

Comparison of no stent fixation, endoscopic suturing, and a novel over-the-scope clip for stent fixation in preventing migration of fully covered self-expanding metal stents: a retrospective comparative study (with video).

BACKGROUND AND AIMS: Endoscopic suturing and over-the-scope clips (OTSCs) are used to prevent migration of fully covered self-expandable metal stents (FCSEMSs). Recently, a dedicated OTSC was developed for securing FCSEMSs. Our primary aim was to compare the frequency of stent migration without stent fixation versus fixation with suturing or OTSCs, and out secondary aims were to compare clinical success, procedure duration, and adverse events. METHODS: A retrospective cohort study evaluated the outcome of stent placement throughout the entire GI tract from 2013 to 2021. Stent migration was determined as stent displacement ≥2 cm endoscopically or radiographically. Clinical success was defined as resolution of indication at follow-up. RESULTS: Four hundred thirty-three procedures were performed, 239 (55%) without fixation, 140 (32%) with suturing, and 54 (12%) with OTSCs. Stent migration rates were 62% without fixation, 57% with suturing, and 35% with OTSCs (P = .013). The median time to stent migration was 3 weeks without fixation, 5 weeks with suturing, and 6 weeks with OTSCs (P = .023). The clinical success rate was 43%. The median procedure time for OTSCs was shorter compared with suturing (42 vs 68 minutes, P = .002). Adverse event rates trended toward being lowest with OTSCs at 9% compared with 21% without fixation and 18% with suturing (P > .05). CONCLUSIONS: OTSCs for stent fixation were found to have significantly lower migration rates compared with no fixation and suturing. Moreover, OTSCs were associated with decreased overall procedure time and total costs per procedure while trending to be associated with fewer adverse events.

Effects of mango and mint pod-based e-cigarette aerosol inhalation on inflammatory states of the brain, lung, heart, and colon in mice.

While health effects of conventional tobacco are well defined, data on vaping devices, including one of the most popular e-cigarettes which have high nicotine levels, are less established. Prior acute e-cigarette studies have demonstrated inflammatory and cardiopulmonary physiology changes while chronic studies have demonstrated extra-pulmonary effects, including neurotransmitter alterations in reward pathways. In this study we investigated the impact of inhalation of aerosols produced from pod-based, flavored e-cigarettes (JUUL) aerosols three times daily for 3 months on inflammatory markers in the brain, lung, heart, and colon. JUUL aerosol exposure induced upregulation of cytokine and chemokine gene expression and increased HMGB1 and RAGE in the nucleus accumbens in the central nervous system. Inflammatory gene expression increased in the colon, while gene expression was more broadly altered by e-cigarette aerosol inhalation in the lung. Cardiopulmonary inflammatory responses to acute lung injury with lipopolysaccharide were exacerbated in the heart. Flavor-specific findings were detected across these studies. Our findings suggest that daily e-cigarette use may cause neuroinflammation, which may contribute to behavioral changes and mood disorders. In addition, e-cigarette use may cause gut inflammation, which has been tied to poor systemic health, and cardiac inflammation, which leads to cardiovascular disease.

The use of e-cigarettes or 'vaping' has become widespread, particularly among young people and smokers trying to quit. One of the most popular e-cigarette brands is JUUL, which offers appealing flavors and a discrete design. Many e-cigarette users believe these products are healthier than traditional tobacco products. And while the harms of conventional tobacco products have been extensively researched, the short- and long-term health effects of e-cigarettes have not been well studied. There is even less information about the health impacts of newer products like JUUL. E-cigarettes made by JUUL are different relative to prior generations of e-cigarettes. The JUUL device uses disposable pods filled with nicotinic salts instead of nicotine. One JUUL pod contains as much nicotine as an entire pack of cigarettes (41.3 mg). These differences make studying the health effects of this product particularly important. Moshensky, Brand, Alhaddad et al. show that daily exposure to JUUL aerosols increases the expression of genes encoding inflammatory molecules in the brain, lung, heart and colon of mice. In the experiments, mice were exposed to JUUL mint and JUUL mango flavored aerosols for 20 minutes, 3 times a day, and for 4 and 12 weeks. The changes in inflammatory gene expression varied depending on the flavor. This suggests that the flavorings themselves contribute to the observed changes. The findings suggest that daily use of pod-based e-cigarettes or e-cigarettes containing high levels of nicotinic salts over months to years, may cause inflammation in various organs, increasing the risk of disease and poor health. This information may help individuals, clinicians and policymakers make more informed decisions about e-cigarettes. Further studies assessing the impact of these changes on long-term physical and mental health in humans are desperately needed. These should assess health effects across different e-cigarette types, flavors and duration of use.

Management of Difficult Choledocholithiasis.

Over 30% of all endoscopic retrograde cholangiography procedures in the US are associated with biliary stone extraction, and over 10-15% of these cases are noted to be complex or difficult. The aim of this review is to define the characteristics of difficult common bile duct stones and provide an algorithmic therapeutic approach to these difficult cases. We describe additional special clinical circumstances in which difficult biliary stones are identified and provide additional management strategies to aid endoscopic stone extraction efforts.

Prospective Observational Trial of a Nonocclusive Dilatation Balloon in the Management of Tracheal Stenosis.

OBJECTIVES: Tracheal stenosis is a debilitating condition that often presents as an emergency and is challenging to treat. Dilatation may avoid tracheostomy or costly tracheal resection and reconstruction. Traditional dilators cause complete occlusion, preventing oxygenation and ventilation, limiting the safe duration of dilatation, and increasing the risk of hypoxic injury or barotrauma. The study authors here assessed an innovative nonocclusive tracheal dilatation balloon, which may improve patient safety by allowing continuous gas exchange. DESIGN: A prospective observational study of 20 discrete dilatation procedures performed in 13 patients under general anesthesia. The primary outcomes were the ability to ventilate during dilatation and the preservation of peripheral oxygen saturation. Secondary outcomes included a measured reduction in stenosis, improvement in Cotton-Myer grading, and procedure-related adverse events. SETTING: At a single university (academic) hospital. PARTICIPANTS: Consenting adult patients with acquired tracheal stenosis. INTERVENTIONS: Access to the airway was maintained by a rigid bronchoscope or supraglottic airway device, as deemed appropriate. Continuous conventional ventilation was provided during 3-minute balloon dilatations. MEASUREMENTS AND MAIN RESULTS: Heart rate, airway pressure, end-tidal carbon dioxide partial pressure, and peripheral oxygen saturation were measured, and adverse events were recorded. Ventilation was satisfactory in all patients. Peripheral saturation remained greater than 94% in 19 of the 20 (95%) procedures. Stenosis internal diameter and grading were improved. Two patients had minor reversible adverse events (coughing and laryngospasm), which did not prevent completion of the procedure. CONCLUSIONS: The authors report the first human trial of the device, in which continuous conventional ventilation could be provided during all tracheal balloon dilatation procedures. Larger trials are needed to confirm improved patient safety and comparative efficacy.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets.

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.

Dual use of e-cigarettes with conventional tobacco is associated with increased sleep latency in cross-sectional Study.

The health effects of e-cigarettes remain relatively unknown, including their impact on sleep quality. We previously showed in a pilot study that females who smoke both conventional tobacco and vape e-cigarettes (dual users) had decreased sleep quality (measurement of how well an individual is sleeping) and increased sleep latency (amount of time to fall asleep), suggesting an influence by gender. Cough is also known to adversely impact sleep quality and may be caused by inhalant use. As a result, we undertook this study to assess the impact of e-cigarette, conventional tobacco, and dual use on sleep quality, sleep latency, cough, and drug use. Participants (n = 1198) were recruited through online surveys posted to social media sites with a monetary incentive. Participants were grouped by inhalant use, with 8% e-cigarette users, 12% conventional tobacco users, 30% dual users, and 51% non-smokers/non-vapers. Dual use of e-cigarettes and conventional tobacco was associated with increased sleep latency relative to non-smokers/non-vapers by multivariable linear regression (mean difference of 4.08; 95% CI: 1.12 to 7.05, raw p = 0.007, adjusted p = 0.042); however, dual usage was not significantly associated with sleep quality relative to non-smokers/non-vapers (mean difference 0.22, 95%CI: (-0.36, 0.80), raw p = 0.452, adjust p = 0.542). Dual use was also associated with a higher reporting of cough (p = 0.038), as well as increased marijuana (p < 0.001) and cocaine (p < 0.001) usage. This study demonstrates that  dual use is associated with longer sleep latency, and suggests that the shared component of nicotine may be a driver. Because sleep broadly impacts multiple aspects of human health, defining the associations of e-cigarettes and vaping devices on sleep is critical to furthering our understanding of their influence on the body.

Endoscopic Mucosal Resection in Children.

OBJECTIVES: Endoscopic mucosal resection (EMR) for removal of large polyps is well established in adults. EMR technique in the pediatric population is less utilized due to lower incidence of large intestinal polyps in pediatric patients and limited EMR training for pediatric gastroenterologists. The aim of this study is to retrospectively review safety and efficacy of pediatric EMR cases at two large, tertiary referral centers with adult and pediatric EMR expertise. METHODS: A retrospective chart review was conducted at Cedars-Sinai Medical Center and Cincinnati Children's Hospital Medical Center from January 2012 to May 2021. Demographic, clinical, technical and follow up data were collected for patients <18 years of age who underwent EMR during the study period. RESULTS: Fifteen pediatric EMR procedures were identified in 11 patients (five male, six female) during the study period. Indication was most frequently rectal bleeding. Polyp size removed ranged from 9 to 60 mm and pathology was consistent with juvenile inflammatory polyps in six patients. Technical success was achieved in 14 of 15 (93%) of EMRs with clinical success (desired clinical outcome) in all 13 procedures with clinical follow-up. There were no adverse events. CONCLUSIONS: This study identifies a case series of pediatric patients who underwent EMR at two tertiary care centers. This series demonstrates successful EMR in children and shows a high technical and clinical success rate with a low complication rate. More investigation into EMR in pediatric patients is necessary, and its use should be isolated to centers with endoscopists with specific experience in EMR techniques.

A Financial Plot to Reduce the Burden of Medical School Tuition Fees.

Tuition fees for medical school are continuously and riotously increasing. This upsurge is amassing debts on the backs of students. In the class of 2018, 75% finished medical school with an outstanding balance of $196,520, on average-a $5826 increase from 2017. Tuition fees differ in terms of the ownership of the medical school (public vs. private) and according to the medical student residence status (in-state or out-of-state). It is critical that students arrange a long-term budget that shows them where they stand: in surplus or in deficit. Students may classify expenditures into two groups: "fixed" and "variable," where they can manipulate the variable expenses to fit into their budget. To pay for their tuition, medical students have four possibilities: cash, scholarships and grants, service-obligation scholarships, and loans. Loans are the most common alternatives, and so there are Traditional Repayment Plans and Income-Driven Repayment Plans. This article serves to provide medical students with attainable alternatives for funding their education and for repaying their debts.

Feasibility and safety study of 22-gauge endoscopic ultrasound (EUS) needles for portal vein sampling in a swine model.

Background and study aims Endoscopic ultrasound (EUS) has been used for portal vein sampling in patients with pancreaticobiliary cancers for enumerating circulating tumor cells but is not yet a standard procedure. Further evaluation is needed to refine the methodology. Therefore, we evaluated the feasibility and safety of 19-gauge (19G) versus a 22-gauge (22 G) EUS fine-needle aspiration needles for portal vein sampling in a swine model. Methods Celiotomy was performed on two farm pigs. Portal vein sampling occurred transhepatically. We compared 19 G and 22 G needles coated interiorly with saline, heparin or ethylenediaminetetraacetic acid (EDTA). Small- (10 mL) and large- (25 mL) volume blood collections were evaluated. Two different collection methods were tested: direct-to-vial and suction syringe. A bleeding risk trial for saline-coated 19 G and 22 G needles was performed by puncturing the portal vein 20 times. Persistent bleeding after 3 minutes was considered significant. Results All small-volume collection trials were successful except for 22 G saline-coated needles with direct-to-vial method. All large-volume collection trials were successful when using suction syringe; direct-to-vial method for both 19 G and 22 G needles were unsuccessful. Collection times were shorter for 19 G vs. 22 G needles for both small and large-volume collections ( P  < 0.05). Collection times for saline-coated 22 G needles were longer compared to heparin/EDTA-coated ( P  < 0.05). Bleeding occurred in 10 % punctures with 19 G needles compared to 0 % with 22 G needles. Conclusion The results of this animal study demonstrate the feasibility and the safety of using 22 G needles for portal vein sampling and can form the basis for a pilot study in patients.