126 research outputs found
Thermal ablation of liver tumours: steps for further improvement
No full textThermal ablation is a treatment for liver tumours in which a needle is inserted into the tumour and destroys tumour cells by heating. This can be applied as an alternative to surgical resection in which a part of the liver with the tumour is removed. The main benefits of ablation included its tissue-sparing nature, low complication rates and short length of stay. Regarding these advantages, the question arises whether ablation can be considered as a first line treatment for small liver tumours. Ruiter performed a multicentre study comparing ablation to resection for colorectal liver metastasis and found comparable overall survival rates and lower complication rates for ablation as compared to resection. Moreover, this thesis has shown that ablation is also an effective and repeatable treatment for primary liver cancer (hepatocellular carcinoma) in selected patients. The most important factor defining technical success after ablation is a complete coverage of the targeted tumour by the ablation zone, with a sufficient ablation margin. Ruiter confirmed the poor predictability of ablation zone dimensions solely based on the applied energy. Also, a novel 3D margin software tool was applied to analyse ablation margins. The tumour diameter and ablation margin were identified as the most important predictors for ablation site recurrence. Additionally, the application of a robotic system for needle placement for ablation was investigated. It was shown that only one needle placement attempt was needed using the robotic system, compared to multiple attempts without using the robotic system
Hepatic artery and portal vein Doppler ultrasound reference values in children aged 0-17 years old
No full textINTRODUCTION: Doppler ultrasound of the portal vein peak systolic velocity and hepatic artery peak systolic velocity and resistive index in children is often performed during abdominal ultrasound for the assessment of liver and other abdominal pathology. However, evidence-based reference values are not available. We aimed to determine these reference values and to investigate whether they are age-dependent.METHODS: Children who underwent abdominal ultrasound between 2020 and 2021 were retrospectively identified. Patients without hepatic or cardiac abnormalities at the time of ultrasound or during at least 3 months follow-up were eligible for the study. Ultrasound without hepatic hilum portal vein peak systolic velocity and/or hepatic artery peak systolic velocity and resistive index measurements were excluded. Age-dependent changes were analyzed using linear regression. Normal range reference values were described using percentiles for all ages, and for age subgroups.RESULTS: One-hundred ultrasound examinations performed in 100 healthy children aged 0-17.9 years (median 7.8 years, interquartile range 1.1-14.1 years) were included. Ninety-nine portal vein peak systolic velocity and 80 hepatic artery peak systolic velocity and resistive index measurements were obtained. There was no significant association between portal vein peak systolic velocity and age (β = -0.056, p = 0.68). There were significant associations between age and hepatic artery peak systolic velocity, and between age and hepatic artery resistive index (β = -0.873, p = 0.04 and β = -0.004, p < 0.001, respectively). Detailed reference values were provided for all ages, and for age subgroups.CONCLUSION: Reference values for the hepatic hilum portal vein peak systolic velocity, hepatic artery peak systolic velocity, and hepatic artery resistive index in children were established. Portal vein peak systolic velocity is not age-dependent, whereas hepatic artery peak systolic velocity and hepatic artery resistive index decrease when children get older.</p
A prospective multicentre trial on survival after Microwave Ablation VErsus Resection for Resectable Colorectal liver metastases (MAVERRIC).
No full textAIM
This multi-centre prospective cohort study aimed to investigate non-inferiority in patients' overall survival when treating potentially resectable colorectal cancer liver metastasis (CRLM) with stereotactic microwave ablation (SMWA) as opposed to hepatic resection (HR).
METHODS
Patients with no more than 5 CRLM no larger than 30 mm, deemed eligible for both SMWA and hepatic resection at the local multidisciplinary team meetings, were deliberately treated with SMWA (study group). The contemporary control group consisted of patients with no more than 5 CRLM, none larger than 30 mm, treated with HR, extracted from a prospectively maintained nationwide Swedish database. After propensity-score matching, 3-year overall survival (OS) was compared as the primary outcome using Kaplan-Meier and Cox regression analyses.
RESULTS
All patients in the study group (n = 98) were matched to 158 patients from the control group (mean standardised difference in baseline covariates = 0.077). OS rates at 3 years were 78% (Confidence interval [CI] 68-85%) after SMWA versus 76% (CI 69-82%) after HR (stratified Log-rank test p = 0.861). Estimated 5-year OS rates were 56% (CI 45-66%) versus 58% (CI 50-66%). The adjusted hazard ratio for treatment type was 1.020 (CI 0.689-1.510). Overall and major complications were lower after SMWA (percentage decrease 67% and 80%, p < 0.01). Hepatic retreatments were more frequent after SMWA (percentage increase 78%, p < 0.01).
CONCLUSION
SMWA is a valid curative-intent treatment alternative to surgical resection for small resectable CRLM. It represents an attractive option in terms of treatment-related morbidity with potentially wider options regarding hepatic retreatments over the future course of disease
pH-Responsive Elastin-Like Polypeptide Designer Condensates
No full textBiomolecular condensates
are macromolecular complexes formed by
liquid–liquid phase separation. They regulate key biological
functions by reversibly compartmentalizing molecules in cells, in
a stimulus-dependent manner. Designing stimuli-responsive synthetic
condensates is crucial for engineering compartmentalized synthetic
cells that are able to mimic spatiotemporal control over the biochemical
reactions. Here, we design and test a family of condensate-forming,
pH-responsive elastin-like polypeptides (ELPs) that form condensates
above critical pH values ranging between 4 and 7, for temperatures
between 20 and at 37 °C. We show that the condensation occurs
rapidly, in sharp pH intervals (ΔpH < 0.3). For eventual
applications in engineering synthetic cell compartments, we demonstrate
that multiple types of pH-responsive ELPs can form mixed condensates
inside micron-sized vesicles. When genetically fused with enzymes,
receptors, and signaling molecules, these pH-responsive ELPs could
be potentially used as pH-switchable functional condensates for spatially
controlling biochemistry in engineered synthetic cells
Mass-Forming Portal Biliopathy Presenting as Extreme Wall-Thickening of the Common Bile Duct
No full textPortal biliopathy refers to biliary tree abnormalities in patients with peribiliary collateral vessels and non-neoplastic extrahepatic portal vein occlusion. These biliary abnormalities are caused by vascular compression and ischemic damage of the biliary tree, which can result in bile duct compression, stenosis, fibrotic strictures, bile duct dilation, and thickening of the bile duct wall. Portal biliopathy is difficult to distinguish from cholangiocarcinoma, IgG4-related disease, and sclerosing cholangitis. Although most patients are asymptomatic, portal biliopathy can lead to serious complications, such as recurrent cholangitis. This case illustrates the importance of including portal biliopathy in the differential diagnosis at an early stage, especially in patients with portal hypertension. With early recognition, the need for additional invasive diagnostic procedures such as biopsies is minimized. Pathogenesis, clinical presentation, diagnostics, and treatment options of portal biliopathy are described in the article.</p
Hyperammonemic Encephalopathy in a Patient with Pancreatic Neuroendocrine Tumor and Portosystemic Shunt
No full textHyperammonemia can lead to encephalopathy and may be accompanied by a diagnostic dilemma. Imaging as well as biochemical analyses are the cornerstone for identifying possible underlying causes such as severe liver disease or urea cycle defect. We report a case of a patient that presented with neurological deficits based on hyperammonemia in the presence of a large pancreatic neuroendocrine tumor (PNET) and portosystemic shunts in the liver. Prior cases are rather scarce, and the exact mechanism is not fully understood. The case illustrates the added value of a multimodality imaging approach in patients presenting with hyperammonemia-induced encephalopathy
Elastin-like polypeptide coacervates as reversibly triggerable compartments for synthetic cells
No full textAbstract Compartmentalization is a vital aspect of living cells to orchestrate intracellular processes. In a similar vein, constructing dynamic and responsive sub-compartments is key to synthetic cell engineering. In recent years, liquid-liquid phase separation via coacervation has offered an innovative avenue for creating membraneless organelles (MOs) within artificial cells. Here, we present a lab-on-a-chip system to reversibly trigger peptide-based coacervates within cell-mimicking confinements. We use double emulsion droplets (DEs) as our synthetic cell containers while pH-responsive elastin-like polypeptides (ELPs) act as the coacervate system. We first present a high-throughput microfluidic DE production enabling efficient encapsulation of the ELPs. The DEs are then harvested to perform multiple MO formation-dissolution cycles using pH as well as temperature variation. For controlled long-term visualization and modulation of the external environment, we developed an integrated microfluidic device for trapping and environmental stimulation of DEs, with negligible mechanical force, and demonstrated a proof-of-principle osmolyte-based triggering to induce multiple MO formation-dissolution cycles. In conclusion, our work showcases the use of DEs and ELPs in designing membraneless reversible compartmentalization within synthetic cells via physicochemical triggers. Additionally, presented on-chip platform can be applied over a wide range of phase separation and vesicle systems for applications in synthetic cells and beyond
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