BACKGROUND:Endovascular procedures are the preferred method for treating peripheral arterial disease. However, limited imaging options during these procedures, such as X-rays and contrast media, expose patients and healthcare professionals to potentially harmful radiation. This study introduces a robotic ultrasound system (RUSS) for navigating endovascular procedures in order to reduce radiation and provide additional information. METHODS:The RUSS comprises a seven-degree-of-freedom robotic arm that navigates an ultrasound transducer across a specific region of interest. The system is controlled by a self-programed software designed to navigate the robotic arm in a methodical and reproducible manner using a foot switch. RESULTS:An endovascular surgeon investigated the guidance and visibility of various guidewires and successfully implanted three stents in a vascular leg phantom using the RUSS without further radiation exposure. CONCLUSIONS:The innovative set-up has several potential applications, including radiation-free endovascular procedures as well as health screening and diagnostic support in vascular medicine.

PURPOSE:To evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom.MATERIALS AND METHODS:An anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft.RESULTS:The procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems.CONCLUSIONS:The study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.

To find out whether application of cold atmospheric plasma (CAP) affects microcirculation in chronic wounds.

Zielsetzung Die zur Navigation von endovaskulärem Fremdmaterial genutzte fluoroskopische Bildgebung birgt Gesundheitsrisiken. Strahlenfreie Trackingmethoden versprechen Abhilfe zu schaffen, müssen aber hohe klinische Anforderungen (z.B. Trackinggenauigkeit) erfüllen. Ziel der Studie war die strahlungsfreie Implantation eines thorakalen Aortenstentgrafts mittels einer neu entwickelten Kombination aus faseroptischen und elektromagnetischen (EM)-Sensoren im anthropomorphen Phantom.

Cancer will be the leading cause of death in a few decades. In line with minimal invasive lung cancer surgery, surgeons loose most of their tactile tissue information and need an additional tool of intraoperative tissue navigation during surgery. Confocal laser microscopy is a well-established method of tissue investigation. In this ex-vivo pilot study, we evaluated an endoscopic confocal laser microscope (eCLM) that does not need any fluorescent dye as a diagnostic tool in non-malignant and malignant pulmonary tissue and distal stapler resection margins, respectively. In seven cases, an eCLM was used for examining pulmonary tissue ex-vivo . Images of non-malignant and non-small cell lung cancer tissue and distal stapler resection margins were characterized in terms of specific signal-patterns. No fluorescent dye was used. Correlations to findings in conventional histology were systematically recorded and described. Healthy lung tissue showed hyperreflectoric alveolar walls with dark alveolar spaces. Hyperreflective nets indicated the tumor stroma; whereas the hyperreflective areas indicated the tumor cell clusters. Compared to adenocarcinoma tissue, tissue from squamous cell carcinoma showed more distinctive hyperreflective stroma nets. eCLM characteristics seen in non-malignant and malignant tissue were also visible in distal stapler resection margins and so therefore it was feasible to distinguish between healthy lung tissue and lung cancer. This pilot study shows that the assessment of pulmonary tissue with this eCLM for minimally invasive surgical approach without any fluorescent dye is feasible. It enables to differentiate between benign and malignant tissue in pulmonary specimen by easy to evaluate and reproducible parameters.

Introduction: 3D printing has a wide range of applications in medicine. In surgery, this technique can be used for preoperative planning of complex procedures, production of patient specific implants, as well as training. However, accuracy evaluations of 3D vascular models are rare. Objectives: Aim of this study was to investigate the accuracy of patient-specific 3D-printed aortic anatomies. Methods: Patients suffering from aorto-iliac aneurysms and with indication for treatment were selected on the basis of different anatomy and localization of the aneurysm in the period from January 1st 2014 to May 27th 2016. Six patients with aorto-iliac aneurysms were selected out of the database for 3D-printing. Subsequently, computed tomography (CT) images of the printed 3D-models were compared with the original CT data sets. Results: The mean deviation of the six 3D-vascular models ranged between -0.73 mm and 0.14 mm compared to the original CT-data. The relative deviation of the measured values showed no significant difference between the 3D-vascular and the original patient CT-data. Conclusion: Our results showed that 3D printing has the potential to produce patient-specific 3D vascular models with reliable accuracy. This enables the use of such models for the development of new endovascular procedures and devices. (C) 2020 Elsevier GmbH. All rights reserved.

During endovascular aneurysm repair (EVAR) procedures, medical instruments are guided with two-dimensional (2D) fluoroscopy and conventional digital subtraction angiography. However, this guidance requires X-ray exposure and contrast agent administration, and the depth information is missing. To overcome these drawbacks, a three-dimensional (3D) guidance approach based on tracking systems is introduced and evaluated [1].

Background: Chronic wounds, such as venous leg ulcers, diabetic foot ulcers, and pressure ulcers, impose a significant burden on patients and health care systems worldwide. Cold atmospheric plasma (CAP) accelerates wound healing and decreases bacterial load in chronic wounds in both in vitro and in vivo experiments. For the first time, we examined the effects of a repetitive application of CAP on the microcirculation in chronic wounds. Hypothesis: The repetitive application of cold atmospheric plasma application further improves microcirculation in chronic wounds. Methods: Twenty patients with chronic wounds were treated repetitively with CAP. The repetitive application consisted of three CAP sessions, each lasting 90 s and separated by a 10-minute microcirculation measuring period. Microcirculation parameters were assessed with combined Laser-Doppler-Flowmetry and spectrophotometry in a tissue depth of 2 mm. Results: Tissue oxygen saturation was significantly increased after the first CAP application. The effect amplitude and duration were further increased after the second and third CAP application with a maximum increase by 16,7% (percent change; p = 0,004 vs. baseline) after the third application. There was no significant increase in capillary blood flow until the third CAP application. After the third CAP application, an increase by 22,6% (p = 0,014) was observed. Postcapillary filling pressure was not significantly increased over the measuring period. The repetitive application of CAP further enhances the microcirculation in chronic wounds compared to a single application. Conclusion: The repetitive application of CAP boosts and prolongs tissue oxygen saturation and capillary blood flow in chronic wounds compared to a single application. This insight could provide an impetus for new treatment protocols.

ZUSAMMENFASSUNGSeit der Konzeption des Turing-Testes 1950 von Alan Turing und über die Beschreibung und Entwicklung erster künstlicher neuronaler Netzwerke 1951 durch Minsky, wenden wir im Jahr 2020 Methoden der Künstlichen Intelligenz (KI) regelhaft an, ohne dass uns dies bewusst ist. Navigationssysteme, automatische Übersetzungssysteme, die Spracherkennung in den Mobiltelefonen oder der Hochgeschindigkeitshandel an den Börsen verwenden heute bereits Methoden des sog. maschinellen Lernens. Die Entwicklung der kommenden Dekaden ist derzeit noch nicht abzuschätzen. Experten stellen für die Anwendung von künstlicher Intelligenz nicht mehr in Frage, ob sie kommt, sondern differieren nur noch in den unterschiedlichen Annahmen wann sie kommt.Die ersten weit verbreiteten Anwendungen der KI werden wahrscheinlich in Form von Computer-Augmentation der menschlichen Leistungsfähigkeit sein. In Zukunft wird ein Chirurg feststellen, dass die AI-Analyse von bevölkerungs- und patientenspezifischen Daten jede Phase der Versorgung ergänzen wird. Eine automatisierte Analyse aller präoperativen mobilen und klinischen Daten könnte einen patientenspezifischeren Risikoscore für die operative Planung liefern und wertvolle Prädiktoren für die postoperative Versorgung bieten. Im Vordergrund stehen für klinisch tätige Ärzte unter dem Stichwort Digitalisierung und Health IT vornehmlich Aspekte der Patientensicherheit, der sicheren Anwendung von KI-Algorithmen per se und der Datensicherheit. Um die klinische Akzeptanz von KI-Anwendungen zukünftig zu erhöhen, sind curriculäre und extracurrikuläre Ausbildungen aufseiten des medizinischen Personals notwendig. Der notwendige Kompetenzerwerb verlangt eine aktive Auseinandersetzung mit den Kernthemen der digitalen Transformation.

Background:Peripheral endovascular interventions are now standard therapy in vascular medicine.However, an unsolved problem continues to be the need of using hazardous X-rays and kidney toxic contrast agents in these procedures.Navigation by ultrasound could be an alternative in this context.Nevertheless, the hitherto uncomfortable manual transducer guidance makes these interventions a challenging task, as it is difficult to keep the transducer always in the intervention focus and to reproduce settings exactly. Objectives:Aim of the research project is the development of a robot assistance system (RAS) for the implementation of ultrasound-supported peripheral endovascular interventions. Materials and methods:In cooperation with the Institute of Robotics and Cognitive Systems at the University of Lübeck, the development of an intelligent transducer control system for duplex sonographic navigation of peripheral endovascular interventions took place.For the project, the KUKA LBR iiwa 7 R800 robot system was used. Results:We developed a robot assistance system (RAS) which guides the transducer in peripheral endovascular interventions and always presents the intervention focus to the surgeon. Conclusion:With the help of RAS it has become possible to perform duplex-controlled peripheral endovascular interventions comfortably as an alternative to conventional X-ray assisted interventions.In addition to the avoidance of X-rays, this has the further effect of real-time information of hemodynamic parameters.

ZusammenfassungEin 49-jähriger Patient stellte sich mit einer langsam progredienten, ca. 7 cm großen Schwellung in der linken Kniekehle vor. Sonografisch und MR-tomografisch zeigte sich das Bild eines postthrombotischen Syndroms am linken Bein mit einem langstreckigen chronischen venösen iliofemoralen Verschluss und ausgeprägten Kollateralen sowie Varixkonvoluten in der linken Kniekehle, die der beklagten Schwellung entsprachen. Es erfolgte die Endophlebektomie der Vena femoralis und Vena femoralis profunda mit einer ventralen Rekonstruktion durch eine bovine Perikard-Patch-Plastik mit Rekanalisation der chronisch okkludierten venösen Iliakalachse mit langstreckiger Stentangioplastie als Hybridoperation. Abschließend wurde eine inguinale AV-Fistel angelegt. Postoperativ entwickelte der Patient einen Frühverschluss der venösen iliofemoralen Strombahn und eine inguinale Lymphfistel. Aufgrund dieser erfolgte zunächst kein operativer, sondern ein perkutaner transjugulärer, letztlich frustraner Rekanalisationsversuch. Die inguinale Heilung benötigte bis zum Sistieren der Lymphexsudation 8 Wochen. Nach diesem Zeitintervall entschieden wir uns aufgrund der zu erwartenden schlechten sekundären Offenheitsrate gegen eine operative Revision, sodass therapeutisch nur die Antikoagulation und Kompression blieb. Die Ursache des dargestellten Frühverschlusses bleibt unklar, mögliche Ursachen und sich daraus ergebende Konsequenzen werden diskutiert.

A 49-year-old patient presented with a slowly progressing about 7cm tumor in the left fossa poplitea. Ultrasonography and MRI showed a postthrombotic syndrome of the left leg with a chronic occlusion of the iliofemoral venes, pronounced inguinal collaterals as well as varix convolutions in the left fossa poplitea, which corresponded to the tumor complained. Endophlebectomy of the vena femoralis and vena femoralis profunda was carried out with a ventral reconstruction using bovine pericardial patch plasty followed by recanalization of the chronically occluded venous iliofemoral axis with stentangioplasty. Finally, an inguinal AV fistula was created. Postoperatively, the patient developed early reocclusion of the recanalized iliofemoral venous axis and an inguinal lymph fistula. Therefore, initially planned surgical recanalization was not possible. We performed a not successful percutaneous transjugular recanalization attempt. The inguinal healing took eight weeks to stop lymph exudation. After this time, we decided against an operative revision due to the expected poor secondary patency rate. The cause of the early reocclusion remains unclear, possible causes and resulting consequences are discussed.

Purpose During endovascular aneurysm repair (EVAR) procedures, medical instruments are guided with two-dimensional (2D) fluoroscopy and conventional digital subtraction angiography. However, this requires X-ray exposure and contrast agent is used, and the depth information is missing. To overcome these drawbacks, a three-dimensional (3D) guidance approach based on tracking systems is introduced and evaluated. Methods A multicore fiber with fiber Bragg gratings for shape sensing and three electromagnetic (EM) sensors for locating the shape were integrated into a stentgraft system. A model for obtaining the located shape of the first 38 cm of the stentgraft system with two EM sensors is introduced and compared with a method based on three EM sensors. Both methods were evaluated with a vessel phantom containing a 3D-printed vessel made of silicone and agar-agar simulating the surrounding tissue. Results The evaluation of the guidance methods resulted in average errors from 1.35 to 2.43 mm and maximum errors from 3.04 to 6.30 mm using three EM sensors, and average errors from 1.57 to 2.64 mm and maximum errors from 2.79 to 6.27 mm using two EM sensors. Moreover, the videos made from the continuous measurements showed that a real-time guidance is possible with both approaches. Conclusion The results showed that an accurate real-time guidance with two and three EM sensors is possible and that two EM sensors are already sufficient. Thus, the introduced 3D guidance method is promising to use it as navigation tool in EVAR procedures. Future work will focus on developing a method with less EM sensors and a detailed latency evaluation of the guidance method.

Zusammenfassung Hintergrund Die periphere endovaskuläre Chirurgie ist nach wie vor durch die Anwendung von Röntgenstrahlen und Röntgenkontrastmittel für die intraprozedurale Navigation der Instrumentarien ein Verfahren mit potenziellen Risiken und Nebenwirkungen. Projektziel Ziel des RoGUS-PAD (Robotic-Guided Ultrasound System for Peripheral Arterial Disease)-Projektes ist die Entwicklung eines roboterbasierten ultraschallgesteuerten Assistenzsystems für periphere endovaskuläre Interventionen zur Verringerung und ggf. Vermeidung von Röntgenstrahlung und Röntgenkontrastmittel sowie Verbesserung der Echtzeitvisualisierung. Material und Methoden Für die Bildgebung wurde ein 2‑D-Ultraschall-Lineartastkopf (L12‑3, Philips Healthcare, Best, Niederlande) am Endeffektor eines Roboterarms (LBR iiwa 7 R800, KUKA, Augsburg, Deutschland) montiert. Die ersten Versuche wurden an einem eigens für dieses Projekt entwickelten ultraschallfähigen Phantom durchgeführt. Die Bildverarbeitung und Robotersteuerung erfolgten durch ein speziell entwickeltes Programm in C++. Ergebnisse Zur Testung der technischen Umsetzbarkeit des Projektes konnten wir einen semiautomatischen 2‑D-Ultraschallscan einer peripheren Arterie am Phantom durchführen. In 27 von 30 Durchläufen zeigte sich ein erfolgreicher Scanvorgang. Schlussfolgerung Unsere ersten Ergebnisse bestätigten, dass die Entwicklung eines roboterbasierten Assistenzsystems für ultraschallgesteuerte periphere endovaskuläre Interventionen technisch umsetzbar ist. Dies stützt unsere Ambitionen einer Translation des Systems in die tägliche klinische Praxis.

The first choice in diagnostic imaging for patients suffering from peripheral arterial disease is 2D ultrasound (US). However, for a proper imaging process, a skilled and experienced sonographer is required. Additionally, it is a highly user-dependent operation. A robotized US system that autonomously scans the peripheral arteries has the potential to overcome these limitations. In this work, we extend a previously proposed system by a hierarchical image analysis pipeline based on convolutional neural networks in order to control the robot. The system was evaluated by checking its feasibility to keep the vessel lumen of a leg phantom within the US image while scanning along the artery. In 100 of the images acquired during the scan process the whole vessel lumen was visible. While defining an insensitivity margin of 2.74 mm, the mean absolute distance between vessel center and the horizontal image center line was 2.47 mm and 3.90 mm for an easy and complex scenario, respectively. In conclusion, this system presents the basis for fully automatized peripheral artery imaging in humans using a radiation-free approach.

Background: Sclerotherapy is considered to be the method of choice for the treatment of telangiectatic varicose veins (C1 veins). Whereas the use of compression stockings after sclerotherapy is recommended, little is known about the impact of compression on the outcome of sclerotherapy. The aim of this study was to assess the influence of compression on the outcome of injection sclerotherapy of C1 varicose veins. Methods: There were 100 legs of 50 consecutive patients with chronic venous insufficiency (C1) included. After randomization per patient, both legs were treated with sclerotherapy in a predefined area of the thigh (measuring 100 cm(2)), followed by eccentric compression for 24 hours. Group A received no further compression, whereas group B was additionally equipped with compression stockings of 18 to 20 mm Hg above the ankle and continued wearing these for 1 week. Photodocumentation was performed before, 1 week after, and 4 weeks after sclerotherapy, and the clinical outcome was assessed at these postprocedure follow-up dates. The photographs were reviewed by an internal unblinded rater and an independent blinded external rater. Results: There was no discernible difference between the groups in terms of clinical outcome or side effects after 4 weeks. Whereas inter-rater reliability was high, there was no correlation between the raters and patients in terms of outcome. In 55% of the treated legs, the patients deemed the result of the treatment to be good; in 27% of the treated legs, fair; and in 18%, poor. Postprocedure hyperpigmentation occurred in 13% of patients and was comparable in both groups. Compression therapy was found to be comfortable by the majority (58%) of patients. Conclusions: One week of postinterventional compression therapy had no clinical benefit compared with no compression.

Purpose: Endovascular interventions have become standard procedures for the therapy of abdominal aortic aneurysms. Therefore, endovascular surgeons need special skills which have to be learned and trained. Additionally, authentic simulators are needed for further development of new endovascular devices and procedures. The aim of this project was to develop an authentic and modular endovascular simulation environment with patient-specific vascular anatomy for training and research purposes. Material and methods: We first designed a prototype with exchangeable 3D -printed patient-specific vascular anatomy. Then, the feasibility of the prototype was validated by a simulation of an EVAR procedure in a clinical setting. Results: We developed an authentic endovascular simulator with an exchangeable patient-specific vascular anatomy and performed an EVAR procedure under realistic conditions. The evaluation of the accuracy of the vascular models showed little deviation when compared with the original Cr data. Conclusion: Endovascular simulators based on patient-specific 3D-printed vascular models can realistically mimic endovascular procedures and have the potential to be used for further development of new devices and grafts as well as for training purposes. Furthermore, in our opinion they can reduce the use of animals during developmental processes. (C) 2020 Elsevier GmbH. All rights reserved.

Seit der Konzeption des Turing-Testes 1950 von Alan Turing und uber die Beschreibung und Entwicklung erster kunstlicher neuronaler Netzwerke 1951 durch Minsky, wenden wir im Jahr 2020 Methoden der Kunstlichen Intelligenz (KI) regelhaft an, ohne dass uns dies bewusst ist. Navigationssysteme, automatische Ubersetzungssysteme, die Spracherkennung in den Mobiltelefonen oder der Hochgeschindigkeitshandel an den Borsen verwenden heute bereits Methoden des sog. maschinellen Lernens. Die Entwicklung der kommenden Dekaden ist derzeit noch nicht abzuschatzen. Experten stellen fur die Anwendung von kunstlicher Intelligenz nicht mehr in Frage, ob sie kommt, sondern differieren nur noch in den unterschiedlichen Annahmen wann sie kommt. Die ersten weit verbreiteten Anwendungen der KI werden wahrscheinlich in Form von Computer-Augmentation der menschlichen Leistungsfahigkeit sein. In Zukunft wird ein Chirurg feststellen, dass die AI-Analyse von bevolkerungs- und patientenspezifischen Daten jede Phase der Versorgung erganzen wird. Eine automatisierte Analyse aller praoperativen mobilen und klinischen Daten konnte einen patientenspezifischeren Risikoscore fur die operative Planung liefern und wertvolle Pradiktoren fur die postoperative Versorgung bieten. Im Vordergrund stehen fur klinisch tatige Arzte unter dem Stichwort Digitalisierung und Health IT vornehmlich Aspekte der Patientensicherheit, der sicheren Anwendung von KI-Algorithmen per se und der Datensicherheit. Um die klinische Akzeptanz von KI-Anwendungen zukunftig zu erhohen, sind curriculare und extracurrikulare Ausbildungen aufseiten des medizinischen Personals notwendig. Der notwendige Kompetenzerwerb verlangt eine aktive Auseinandersetzung mit den Kernthemen der digitalen Transformation.

In endovascular aortic repair (EVAR) procedures fluoroscopy and conventional digital subtraction angiography are currently used to guide the medical instruments inside the patient. Drawbacks of these methods are X-ray exposure and the usage of contrast agents. Moreover, the fluoroscopy provides only a 2D view, which makes the guidance more difficult. For this reason, a catheter prototype including an optical fiber for shape sensing and three electromagnetic (EM) sensors, which provide the position and orientation information, was built to enable a 3D catheter guidance.