BackgroundIrreversible electroporation (IRE) is a tissue ablation method, which relies on the phenomenon of electroporation. When cells are exposed to a sufficiently electric field, the plasma membrane is disrupted and cells undergo an apoptotic or necrotic cell death. Although heating effects are known IRE is considered as non-thermal ablation technique and is currently applied to treat tumors in locations where thermal ablation techniques are contraindicated.Materials and methods.The manufacturer of the only commercially available pulse generator for IRE recommends a voltage-to-distance ratio of 1500 to 1700 V/cm for treating tumors in the liver. However, major blood vessels can influence the electric field distribution. We present a method for treatment planning of IRE which takes the influence of blood vessels on the electric field into account; this is illustrated on a treatment of 48-year-old patient with a metastasis near the remaining hepatic vein after a right side hemi-hepatectomy.ResultsOutput of the numerical treatment planning method shows that a 19.9 cm3 irreversible electroporation lesion was generated and the whole tumor was covered with at least 900 V/cm. This compares well with the volume of the hypodense lesion seen in contrast enhanced CT images taken after the IRE treatment. A significant temperature raise occurs near the electrodes. However, the hepatic vein remains open after the treatment without evidence of tumor recurrence after 6 months.ConclusionsTreatment planning using accurate computer models was recognized as important for electrochemotherapy and irreversible electroporation. An important finding of this study was, that the surface of the electrodes heat up significantly. Therefore the clinical user should generally avoid placing the electrodes less than 4 mm away from risk structures when following recommendations of the manufacturer.
• Absolute ADC values are highly dependent on the choice of b values. • Absolute ADC thresholds should be used carefully to predict tumour aggressiveness. • Subjective ratings of ADC maps involving b = 0 s/mm ( 2 ) are poor to fair. • Minimum b value greater than 0 s/mm ( 2 ) is recommended for ADC calculation.
Summary Background Loss of skeletal muscle mass is a recognised complication with a prognostic impact in patients with cirrhosis. Aim To explore in a retrospective analysis which muscle compartment most reliably predicts the occurrence of cirrhosis‐associated complications and if there are gender‐related differences. Methods 795 patients with cirrhosis listed for liver transplantation between 2001 and 2014 met the inclusion and exclusion criteria including an abdominal CT scan (±200). Controls were 109 patients who underwent a CT scan after polytrauma. The paraspinal muscles index (PSMI), the abdominal wall muscles index (AWMI) and its combination skeletal muscle index (SMI) were assessed at L3/L4, normalised to the height (cm2/m2). Results 62.0% of patients with cirrhosis had alcoholic liver disease, and 70.6% were male. As compared to controls, a reduction in PSMI and SMI but not AWMI was associated with high model of end‐stage liver disease (MELD) score, high Child‐Pugh class, and the presence or history of cirrhosis‐associated complications in males but not females. PSMI independently predicted the occurrence of bacterial infections (HR 0.932), spontaneous bacterial peritonitis (HR 0.901), hepatic encephalopathy (HR 0.961), and hepatorenal syndrome (HR 0.946) by multivariate Cox regression analysis in a gender‐independent manner. Post‐transplant survival was not associated with the PSMI; neither AWMI nor SMI predicted any clinical endpoints. Conclusions This study links muscle wasting in patients with cirrhosis predominantly to males. However, the presence of a low PSMI mass is a gender‐independent predictor of developing cirrhosis‐associated complications and death. Scores combining the MELD with muscle parameters should be re‐validated by utilizing the PSMI.
BackgroundModular mega-endoprosthesis systems are used to bridge very large bone defects and have become a widespread method in orthopaedic surgery for the treatment of tumours and revision arthroplasty. However, the indications for the use of modular mega-endoprostheses must be carefully considered. Implanting modular endoprostheses requires major, complication-prone surgery in which the limited salvage procedures should always be borne in mind. The management of periprosthetic infection is particularly difficult and beset with problems.Given this, the present study was designed to gauge the significance of periprosthetic infections in connection with modular mega-implants in the lower extremities among our own patients.MethodsPatients who had been fitted with modular endoprosthesis on a lower extremity at our department between September 1994 and December 2011 were examined retrospectively. A total of 101 patients with 114 modular prostheses were identified. Comprising 30 men (29.7 %) and 71 women (70.3 %), their average age at the time of surgery was 67 years (18–92 years).ResultsThe average follow-up period was 27 months (5 months and 2 weeks to 14 years and 11 months) and the drop-out rate was about 8.8 %. Altogether, there were 19 (17.7 %) endoprosthesis infections: 3 early infections and 16 late or delayed infections. The pathogen spectrum was dominated by coagulase-negative staphylococci (36 %) and Staphylococcus aureus (16 %), including 26 % multi-resistant pathogens. Reinfection occurred in 37 % of cases of infection. Tumours were followed by significantly fewer infections than the other indications. Infections were twice as likely to occur after previous surgery.ConclusionIn our findings modular endoprostheses (18 %) are much more susceptible to infection than primary endoprostheses (0.5–2,5 %). Infection is the most common complication alongside the dislocation of proximal femur endoprostheses. Consistent, radical surgery is essential – although even with an adequate treatment strategy, the recurrence rate is very high. Unfortunately, the functional results are frequently unsatisfactory, with amputation often being the last resort. Therefore, the indication for implantation must be carefully considered and discussed in great detail, especially in the case of multimorbid patients with previous joint infections.
Background: Data on liver resection for hepatocellular carcinoma (HCC) without cirrhosis are sparse. The present study was conducted to evaluate the indications and results of liver resection for HCC with regard to safety and efficacy.Methods: Data for patients who had liver resection for HCC without cirrhosis between January 1996 and March 2011 were retrieved retrospectively using a prospective database containing information on all patients who underwent hepatectomy for HCC. Patient and tumour characteristics were analysed for influence on overall and disease-free survival to identify prognostic factors by univariable and multivariable analysis.Results: The 1-, 3-and 5-year overall survival rates after resection with curative intent for HCC without cirrhosis were 84, 66 and 50 per cent respectively. Disease-free survival rates were 69, 53 and 42 per cent respectively. The 90-day mortality rate was 4·5 per cent (5 of 110 patients). Surgical radicality and growth pattern of the tumour were independent prognostic factors for overall survival. Disease-free survival after resection with curative intent was independently affected by growth pattern and by the number and size of tumour nodules. Conclusion:Liver resection for HCC without cirrhosis carries a low perioperative risk and excellent long-term outcome if radical resection is achieved.
Background: ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTHsecreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed.
Purpose: To present the clinical setup and workflow of a robotic assistance system for image-guided interventions in a conventional magnetic resonance imaging (MRI) environment and to report our preliminary clinical experience with percutaneous biopsies in various body regions. Materials and Methods:The MR-compatible, servo-pneumatically driven, robotic device (Innomotion) fits into the 60-cm bore of a standard MR scanner. The needle placement (n ¼ 25) accuracy was estimated by measuring the 3D deviation between needle tip and prescribed target point in a phantom. Percutaneous biopsies in six patients and different body regions were planned by graphically selecting entry and target points on intraoperatively acquired roadmap MR data.Results: For insertion depths between 29 and 95 mm, the average 3D needle deviation was 2.2 6 0.7 mm (range 0.9-3.8 mm). Patients with a body mass index of up to %30 kg/m 2 fitted into the bore with the device. Clinical work steps and limitations are reported for the various applications. All biopsies were diagnostic and could be completed without any major complications. Median planning and intervention times were 25 (range 20-36) and 44 (36-68) minutes, respectively. Conclusion:Preliminary clinical results in a standard MRI environment suggest that the presented robotic device provides accurate guidance for percutaneous procedures in various body regions. Shorter procedure times may be achievable by optimizing technical and workflow aspects.
A multi-centre retrospective study indicates that the fast RFA solver is capable of providing the IR with the predicted lesion in the short time period before the intervention begins when the patient has been clinically prepared for the treatment.
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