Three-dimensional simulator: training for beginners in endovascular embolization with liquid agents

Background: To design a simulator for novices without prior experience in embolization with liquid agents such as n-Butyl cyanoacrylate (n-BCA) and to evaluate the simulator using surveys and post hoc video analysis. Materials and methods: The simulator was created using computer-aided design software and three-dimensionally printed. Before an embolization, trainees completed questionnaires regarding their level of expertise and self-reported confidence level. The participants were shown an instruction video and each participant performed four embolizations on the simulator. Subsequently, the participants completed surveys on self-reported confidence level and assessed the simulator's face and content validity. Results: Five experts and twelve novices trained on the simulator. The experts were radiology residents and fellows with at least 5 years of work experience in interventional radiology. The novices were medical students and radiology residents without any previous experience with embolization. Based on the surveys, the experts assessed the simulator as very useful for embolization training. Performance, e.g. mean duration embolization between experts (mean +/- standard deviation = 189 +/- 42 s) and novices (mean +/- standard deviation = 235 +/- 66 s) were significantly different (p = .001). The overall simulation of the embolization process, simulated complications, and educational capabilities of the simulator were evaluated positively. In the novice group the self-reported confidence level significantly increased (p = .001). Conclusion: The liquid embolization simulator proposed here is a suitable educational tool for training embolization procedures. It reduces the duration of embolization procedures and improves the confidence level of beginners in embolization

Evaluation of Open Surgical and Endovascular Treatment Options for Visceral Artery Erosions after Pancreatitis and Pancreatic Surgery

Purpose: To report and compare the results of endovascular and open surgical treatment for erosion bleeding of visceral arteries following pancreatitis and pancreatic surgery. Materials and Methods: This retrospective study included 65 consecutive patients (46 males, mean age 63 +/- 14 years) presenting with visceral artery erosions between January 2011 and December 2020. Endpoints were technical success, freedom from reintervention, stent-graft-related complications, and 30-day and one-year mortality. Results: The causes of erosion bleeding included complications of surgical treatment for the pancreas and upper gastrointestinal tract (75%), pancreatitis (19%), and spontaneous bleeding (6%). Pancreatectomy was performed in 34 (52%) patients, representing 2% of all pancreatectomy procedures (n = 1645) performed in our hospital during the study period. A total of 37 (57%) patients underwent endovascular treatment (EVT), and 28 (43%) patients had open surgery (OS) as a primary treatment. Eight of 37 (22%) patients in the EVT group underwent stent-graft treatment of the eroded vessels and 28 (78%) coil embolization. Six (9%) patients underwent reintervention with no significant differences between EVT and OS groups (11% vs. 7%, p = 0.692). Postoperative morbidity and complications in 52% of all patients were higher in the OS group than in the EVT group (41% vs. 68%, p = 0.029). The in-hospital 30-days mortality rate for all patients was 25%, and it was higher in the OS group than in the EVT group (14% vs. 39%, p = 0.017). Conclusions: An endovascular-first strategy for treating visceral arteries erosions may be preferred to reduce the complications associated with open surgery if patients are hemodynamically stable and have no anastomotic insufficiency. Endovascular treatment may be associated with better in-hospital survival when compared to primary open surgery. Further studies are required to identify the optimal approach

Comparison of four radiofrequency ablation systems at two target volumes in an ex vivo bovine liver model

PURPOSEWe aimed to validate actually achieved macroscopic ablation volumes in relation to calculated target volumes using four different radiofrequency ablation (RFA) systems operated with default settings and protocols for 3 cm and 5 cm target volumes in ex vivo bovine liver.MATERIALS AND METHODSSixty-four cuboid liver specimens were ablated with four commercially available RFA systems (Radionics Cool-tip, AngioDynamic 1500X, Boston Scientific RF 3000, Celon CelonPower LAB): 16 specimens for each system; eight for 3 cm, and eight for 5 cm. Ablation diameters were measured, volumes were calculated, and RFA times were recorded.RESULTSFor the 3 cm target ablation volume, all tested RFA systems exceeded the mathematically calculated volume of 14.14 cm3. For the 3 cm target ablation volume, mean ablation volume and mean ablation time for each RFA system were as follows: 28.5±6.5 cm3, 12.0±0.0 min for Radionics Cool-tip; 17.1±4.9 cm3, 9.36±0.63 min for AngioDynamic 1500X; 29.7±11.7 cm3, 4.60±0.50 min for Boston Scientific RF 3000; and 28.8±7.0 cm3, 20.85±0.86 min for Celon CelonPower LAB. For the 5 cm target ablation volume, Radionics Cool-tip (48.3±9.9 cm3, 12.0±0.0 min) and AngioDynamic 1500X (39.4±16.2 cm3, 19.59±1.13 min) did not reach the mathematically calculated target ablation volume (65.45 cm3), whereas Boston Scientific RF 3000 (71.8±14.5 cm3, 9.15±2.93 min) and Celon CelonPower LAB (93.9±28.1 cm3, 40.21±1.78 min) exceeded it.CONCLUSIONWhile all systems reached the 3 cm target ablation volume, results were variable for the 5 cm target ablation volume. Only Boston Scientific RF 3000 and Celon CelonPower LAB created volumes above the target, whereas Radionics Cool-tip and AngioDynamic 1500X remained below the target volume. For the 3 cm target ablation volume, AngioDynamic 1500X with 21% deviation was closest to the target volume. For the 5 cm target volume Boston Scientific RF 3000 with 10% deviation was closest

Percutaneous Large-Bore Pulmonary Thrombectomy with the FlowTriever Device: Initial Experience in Intermediate-High and High-Risk Patients

Objectives: This retrospective cohort study investigates outcomes of patients with intermediate-high and high-risk pulmonary embolism (PE) who were treated with transfemoral mechanical thrombectomy (MT) using the large-bore Inari FlowTriever aspiration catheter system. Material and Methods: Twenty-seven patients (mean age 56.1 +/- 15.3 years) treated with MT for PE between 04/2021 and 11/2021 were reviewed. Risk stratification was performed according to European Society of Cardiology (ESC) guidelines. Clinical and hemodynamic characteristics before and after the procedure were compared with the paired Student's t test, and duration of hospital stay was analyzed with the Kaplan-Meier estimator. Procedure-related adverse advents were assessed. Results: Of 27 patients treated, 18 were classified as high risk. Mean right-to-left ventricular ratio on baseline CT was 1.7 +/- 0.6. After MT, a statistically significant reduction in mean pulmonary artery pressures from 35.9 +/- 9.6 to 26.1 +/- 9.0 mmHg (p = 0.002) and heart rates from 109.4 +/- 22.5 to 82.8 +/- 13.8 beats per minute (p < 0.001) was achieved. Two patients died of prolonged cardiogenic shock. Three patients died of post-interventional complications of which a paradoxical embolism can be considered related to MT. One patient needed short cardiopulmonary resuscitation during the procedure due to clot displacement. Patients with PE as primary driver of clinical instability had a median intensive care unit (ICU) stay of 2 days (0.5-3.5 days). Patients who developed PE as a complication of an underlying medical condition spent 11 days (9.5-12.5 days) in the ICU. Conclusion: In this small study population of predominantly high-risk PE patients, large-bore MT without adjunctive thrombolysis was feasible with an acceptable procedure-related complication rate

Fluid preinjection for microwave ablation in an ex vivo bovine liver model assessed with volumetry in an open MRI system

PURPOSEWe aimed to detect possible differences in microwave ablation (MWA) volumes after different fluid preinjections using magnetic resonance imaging (MRI).MATERIALS AND METHODSMWA volumes were created in 50 cuboid ex vivo bovine liver specimens (five series: control [no injection], 10 mL water, 10 mL 0.9% NaCl, 10 mL 6% NaCl, and 10 mL 12% NaCl preinjections; n=10 for each series). The operating frequency (915 megahertz), ablation time (7 min), and energy supply (45 watts) were constant. Following MWA, two MR sequences were acquired, and MR volumetry was performed for each sequence.RESULTSFor both sequences, fluid preinjection did not lead to significant differences in MWA ablation volumes compared to the respective control group (sequence 1: mean MWA volumes ranged from 7.0±1.2 mm [water] to 7.8±1.3 mm [12% NaCl] vs. 7.3±2.1 mm in the control group; sequence 2: mean MWA volumes ranged from 4.9±1.4 mm [12% NaCl] to 5.5±1.9 mm [0.9% NaCl] vs. 4.7±1.6 mm in the control group). The ablation volumes visualized with the two sequences differed significantly in general (P < 0.001) and between the respective groups (control, P ≤ 0.001; water, P < 0.001; 0.9% NaCl, P < 0.001; 6% NaCl, P ≤ 0.001; 12% NaCl, P < 0.001). The volumes determined with sequence 1 were closer to the expected ablation volume of 8 mL compared to those determined with sequence 2.CONCLUSIONFor the fluid qualities and concentrations assessed, there is no evidence that fluid preinjection results in larger coagulation volumes after MWA. Because ablation volumes determined by MRI vary with the sequence used, interventionalists should gain experience in how to interpret postinterventional imaging findings (with the MR scanner, sequences, and parameters used) to accurately estimate the outcome of the interventions they perform

Establishment of a DIN EN ISO 9001:2000 Quality Management System at an epidemiological university institute including the areas of scientific research and teaching

GesamtdissertationZielsetzung: Anwendung der DIN EN ISO 9001:2000 auf ein Universitätsinstitut epidemiologischer Ausrichtung, inklusive der Bereiche Forschung und Lehre, am Beispiel des Institutes für Sozialmedizin, Epidemiologie und Gesundheitsökonomie der Charité Universitätsmedizin Berlin. Material und Methoden: Der Prozeß der Entwicklung und Verfeinerung des Qualitätsmanagementsystems wird in allen wesentlichen Schritten (etwa der Darstellung der klassischen Prozesse für die Arbeitsbereiche des Institutes, der Einführung interner normkonformer Audits, oder der Schaffung und Verbesserung eines verbindlichen Regelwerks in Form eines QM-Handbuchs) bis zur erfolgreichen Zertifizierung beschrieben. Ergebnisse: Das Institut für Sozialmedizin, Epidemiologie und Gesundheitsökonomie etablierte das Qualitätsmanagementsystem eigenständig, ohne externe professionelle Berater. Es wurde von einer autorisierten DIN-akkreditierten Prüfstelle zertifiziert. Die Zertifizierung schließt die Bereiche Forschung und Lehre des Institutes komplett mit ein. Auch die epidemiologische Ausrichtung mit stark dateneingebender und datenverarbeitender Tätigkeit erwies sich als zertifizierbar. Der Abgleich mit zwingenden Aspekten der Norm konnte innerhalb etwa eines Jahres vollzogen werden. Schlussfolgerungen: Sobald die erforderlichen Daten vorliegen, sollte eine genauere Quantifizierung des Nutzens der Zertifizierung angestrebt werden. Themen wie Qualitätsmanagement als strategische Investitionsentscheidung oder das marktstrategische Moment einer Zertifizierung könnten ebenso Gegenstand zukünftiger Untersuchungen sein, wie der Einfluß einer Zertifizierung auf den Lebenszyklus eines Institutes, oder Zertifizierung als Mittel zur Abgrenzung gegen unseriöse Institute.Purpose: Establishment of DIN EN ISO 9001:2000 at a university institute with epidemiological focus, including the areas of scientific research and teaching, exemplary for the Institute for Social Medicine, Epidemiology, and Health Economics at Charité - University Medical Center, Berlin. Materials and Methods: Description of the process of development and refinement of the quality management system regarding all crucial steps (e.g. presentation of classical processes within the different fields of work at the institute, the implementation of internal norm-consistent audits, or the creation and amelioration of the QM-Handbook) towards successful certification. Results: The Institute for Social Medicine, Epidemiology, and Health Economics established the quality management system independently, without external professional consultants. It has been certified by a DIN-accredited inspection authority. The certification includes the areas of scientific research and teaching completely. Also, the epidemiological focus with sound data-input and data-processing operations proved compatible with certification. Imperative aspects of the norm were fulfilled within one year. Conclusion: As soon as required data is available, one should seek further quantification of the benefits of the certification. Topics like quality management as a strategic investment decision or the market strategic momentum of certification could become subject for further analyses, as well as the influence of certification on the life-cycle of institutes or certification as an instrument of separation from shady institutes