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Besides process parameters, powder properties such as grain size, morphology, and chemical composition have the highest impact on the material properties of parts produced by powder-based additive manufacturing. These properties are strongly influenced by the production process of the powder and its feedstock. In the scope of this work, the influence of three different powder producers of Ti6Al4V, on density, chemical composition, and mechanical properties of build samples, is investigated. Furthermore, the effects of the varying atomization process on morphology, particle size distribution, chemical composition, and oxide layers are studied. Particle size distribution and flowability seem to have a minor influence on the production process while density depends highly on the surface topology, sphericity, and nature of the oxide layer, which affect energy intake. Tensile properties are highly influenced by chemical composition, mainly dissolved oxygen, and polluting satellites, while notched bar impact strength is additionally influenced by the oxide layer and suspected TiO2 precipitations caused by it.

Ti6Al4V is the most widely used α‑β Titanium alloy for application in medicine, automotive, and aerospace, known for its high strength and corrosion resistance, but also its high maximal operating temperature of around 420 °C. Combined with its decent weldability under a shield atmosphere it has become a standard alloy for additive manufacturing processes, especially laser and electron beam powder bed fusion (L-PBF). Although this material is well studied, the influence of the L‑PBF process on its tensile properties at elevated temperatures remains almost unexplored. For that reason, this contribution focuses on the analysis of the tensile properties of Ti6Al4V up to 500 °C for different heat treatments and compares it to aerospace standards.Furnace annealed samples reach a tensile strength between 1022 to 660 MPa from room temperature to 500 °C respectively, while stress-relieved specimens reach 1205 to 756 MPa. Stress-relieved samples show a lower ductility at room temperature, but elongation at break increases at high temperature and outperforms furnace annealed samples at 500 °C.

Endoscopic full-thickness resection (EFTR) has expanded the possibilities of endoscopic resection. The full-thickness resection device (FTRD, Ovesco Endoscopy, Tübingen, Germany) combines a clip-based defect closure and snare resection in a single device. Systematic review and meta-analysis on effectiveness and safety of the FTRD in the colon. A total of 26 studies (12 published as full-text articles and 14 conference papers) with 1538 FTRD procedures were included. The pooled estimate for reaching the target lesion was 96.1 % (95 % confidence interval [95 % CI]: 94.6-97.1) and 90.0 % (95 % CI: 87.0-92.3) for technically successful resection. Pooled estimate of histologically complete resection was 77.8 % (95 % CI: 74.7-80.6). Adverse events occurred at a pooled estimate rate of 8.0 % (95 % CI: 5.8-10.4). Pooled estimates for bleeding and perforation were 1.5 % (95 % CI: 0.3-3.3) and 0.3 % (95 % CI: 0.0-0.9), respectively. The rate for need of emergency surgery after FTRD was 1.0 % (95 % CI: 0.4-1.8). The use of the FTRD in the colon shows very high rates of technical success and complete resection (R0) as well as a low risk of adverse events. Emergency surgery after colonic FTRD resection is necessary in single cases only. Die endoskopische Vollwandresektion erweitert die Möglichkeiten endoskopischer Resektionen. Sie basiert auf der Resektion der Läsion einerseits und dem sicheren Verschluss des Resektionsdefekts andererseits. Das Full-Thickness Resection Device (FTRD, Ovesco Endoscopy, Tübingen) vereint beide Schritte in einem Gerät. Typische Indikationen sind sogenannte schwierige oder Non-lifting-Adenome im Kolon. Systematisches Review und Metaanalyse zur Effektivität und Sicherheit der endoskopischen Vollwandresektion im Kolon mit dem FTRD-System. Insgesamt wurden 26 Studien eingeschlossen, darunter 12 Volltextpublikationen und 14 Kongressbeiträge. Die Gesamtzahl der analysierten FTRD-Prozeduren betrug 1538. Die Zielläsion wurde mit einer Rate von 96,1 % (95 %-Konfidenzintervall (95 %-KI): 94,6–97,1) erreicht. Die Resektion war in 90,0 % (95 %-KI: 87,0–92,3) technisch erfolgreich. und eine R0-Resektion gelang mit einer Rate von 77,8 % (95 %-KI: 74,7–80,6). Komplikationen traten bei 8,0 % (95 %-KI: 5,8–10,4) der Prozeduren auf; die Rate der Nachblutungen und Perforationen lag bei 1,5 % (95 %-KI: 0,3–3,3) bzw. 0,3 % (95 %-KI: 0,0–0,9). Die Rate komplikationsbedingter Operationen betrug 1,0 % (95 %-KI: 0,4–1,8). Die endoskopische Vollwandresektion im Kolon mittels FTRD ist effektiv und sicher. Eine R0-Resektion gelingt in vielen Fällen, und insbesondere schwerwiegende Komplikationen mit der Notwendigkeit einer Notfalloperation sind sehr selten.

Lumen-apposing metal stents (LAMS) may be inserted to create gastrointestinal anastomoses under endoscopic ultrasound (EUS) guidance. This new technique has mostly been evaluated as treatment for gastric outlet obstruction (GOO), especially of malignant origin. Technical success was high in the few and small available studies. Aim of this study was to report our experience with this technique and to identify predictors of success in the setting of a large teaching hospital in Germany. All subsequent patients who underwent EUS-guided gastrointestinal anastomosis with LAMS from 02/2016 to 08/2019 were included. We performed a retrospective chart analysis including technical procedural details, basic demographic, and health characteristics. Technical success was defined as successful insertion of LAMS. In patients with GOO, the GOO Scoring System was used; an improvement ≥ 1 point was defined as clinical success. Thirty-five patients (22 female, median age: 79 years) were included. Indication for the anastomosis was malignant GOO in 33 patients. In ten patients LAMS was inserted over a guidewire, in 22 patients direct puncture with the electrocautery delivery system of LAMS was performed, and other techniques were used in two patients. Technical success rate was 80.0%. Adverse events occurred in 14.3%. Clinical success rate was 74.3%. Technical success increased and procedure time decreased significantly during the study period. Distance between the two lumina connected with LAMS was significantly shorter (median: 9 mm) in patients with technical success compared to those without (median: 20 mm, P = 0.004). This distance was identified as predictor of success on multivariate analysis. EUS-guided gastrointestinal anastomosis with LAMS is an emerging technique. Its success mainly depends on the distance between the two lumina that are going to be connected by the LAMS and is influenced by the endoscopist’s experience.

ZUSAMMENFASSUNGDie endoskopische Therapie bei gastrointestinalen Blutungen ist hoch effektiv und sicher, auch unter Einnahme von Antikoagulanzien. Das technische Vorgehen unterscheidet sich nicht vom Vorgehen bei fehlender Einnahme von Antikoagulanzien, wobei z. B. der Stellenwert einer primären OTSC („over-the-scope clip“, Ovesco Endoscopy)-Applikation bei Hochrisikopatienten noch untersucht werden muss. Das Management der Antikoagulation unterscheidet sich zwischen den unterschiedlichen Präparaten und der zugrundeliegenden Indikation und muss dem individuellen Risiko angepasst werden. Thrombozytenaggregationshemmer sollten maximal für die Intervention pausiert und früh wieder verabreicht werden. Das Management unter dualer Plättchenhemmung oder Triple-Therapie ist zwingend interdisziplinär abzusprechen. Bei Niedrigrisikosituation kann die duale Therapie in der Regel fortgeführt werden. Bei vitaler Blutung unter Vollantikoagulation ist eine Antagonisierung empfohlen, bei nicht vitaler Blutung ist diese abhängig vom endoskopischen Erfolg. Die Vollantikoagulation sollte frühestmöglich, in der Regel nach ca. 7 Tagen, wieder aufgenommen werden (Ausnahmen: mechanische Herzklappen, frisch implantierte Bioklappen, sehr hohes Thromboembolierisiko).

Introduction Risk stratification in upper gastrointestinal bleeding (UGIB) currently relies on clinical parameters and risk scores. HemoPill® acute (Ovesco Endoscopy, Tuebingen, Germany) is a pill-shaped, orally administered sensor capsule for real-time blood detection. The aim of this study was to evaluate the system in clinical routine. Material and methods Sixty-one consecutive patients in whom the HemoPill® had been used at 12 international hospitals between July 2019 and March 2020 were retrospectively analysed. Indications for application were the clinical suspicion of UGIB, small bowel bleeding, of rebleeding after hemostasis. Primary endpoints were technical success and bleeding detection/exclusion. Secondary endpoints included adverse events and change of clinical course. Results The capsule was used in 45 (73%) patients with UGIB, in 12 (20%) patients with small bowel bleeding and in four (7%) patients for exclusion of rebleeding. Technical success was 98%. 35/60 (58%) cases were capsule-positive and among these, endoscopy showed bleeding in 20/35 (57%) cases. None of the 25 capsule-negative patients rebled. Emergency endoscopy could be avoided in 18/25 (72%) cases. Serious adverse events did not occur. Conclusion HemoPill®-based blood detection is feasible and safe. Negative capsule results might 'downgrade' the need for urgent endoscopy.

Background Rectal neuroendocrine tumors (NETs) are subepithelial tumors with potential for malignancy. Depending on tumor characteristics, endoscopic or surgical resection is recommended. However, the optimal endoscopic approach is not defined. This is the first larger study evaluating endoscopic full-thickness resection (EFTR) of rectal NETs. Methods For resection, the full-thickness resection device (FTRD) was used. A registry was created as part of post-market clinical follow-up. All cases of rectal NETs in the registry were analyzed retrospectively. Results 31 German centers entered data of 501 FTRD procedures and 40 cases of rectal NETs were identified. The median lesion size was 8 mm. All lesions could be resected using FTRD. The median procedure time was 18.5 minutes. Resection was macroscopically and histologically complete in all cases. Full-thickness resection was achieved in 95 %. No major adverse events occurred. Endoscopic follow-up showed no evidence of residual or recurrent tumor. Conclusion EFTR is safe and effective for resection of smaller rectal NETs. Prospective comparative trials are needed to define the role of EFTR of rectal NETs.

Background Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world. Aim To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection. Methods EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC®, Ovesco Endoscopy, Tubingen, Germany). AWC® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp®, Ovesco Endoscopy, Tubingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp® has been shown in a pre-clinical study in domestic pigs. LiftUp® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events. Results Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation. Conclusion EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

Contemporary cardiac implantable electronic devices such as pacemakers or event recorders are powered by primary batteries. Device replacement due to battery depletion may cause complications and is costly. The goal of energy harvesting devices is to power the implant with energy from intracorporeal power sources such as vibrations and blood flow. By replacing primary batteries with energy harvesters, reinterventions can be avoided and the size of the total device might be reduced. This paper introduces a device with a lever, which is deflected by the blood stream within the right ventricular outflow tract (RVOT), an attractive site for cardiac pacing. The resulting torque is converted to electrical energy by an electromagnetic mechanism. The blood flow harvester weighs 6.4 g and has a volume of 2 cm3, making the harvester small enough for catheter implantation. It was tested in an experimental setup mimicking flow conditions in the RVOT. The blood flow harvester generated a mean power of 14.39 ± 8.38 μW at 60 bpm (1 Hz) and up to 82.64 ± 17.14 μW at 200 bpm (3.33 Hz) during bench experiments at 1 m/s peak flow velocity. Therefore, it presents a viable alternative to power batteryless and leadless cardiac pacemakers.

ObjectiveAcute non-variceal upper gastrointestinal bleeding (NVUGIB) is managed by standard endoscopic combination therapy, but a few cases remain difficult and carry a high risk of persistent or recurrent bleeding. The aim of our study was to compare first-line over-the-scope-clips (OTSC) therapy with standard endoscopic treatment in these selected patients.DesignWe conducted a prospective, randomised, controlled, multicentre study (NCT03331224). Patients with endoscopic evidence of acute NVUGIB and high risk of rebleeding (defined as complete Rockall Score ≥7) were included. Primary endpoint was clinical success defined as successful endoscopic haemostasis without evidence of recurrent bleeding.Results246 patients were screened and 100 patients were finally randomised (mean of 5 cases/centre and year; 70% male, 30% female, mean age 78 years; OTSC group n=48, standard group n=52). All but one case in the standard group were treated with conventional clips. Clinical success was 91.7% (n=44) in the OTSC group compared with 73.1% (n=38) in the ST group (p=0.019), with persistent bleeding occurring in 0 vs 6 in the OTSC versus standard group (p=0.027), all of the latter being successfully managed by rescue therapy with OTSC. Recurrent bleeding was observed in four patients (8.3%) in the OTSC group and in eight patients (15.4%) in the standard group (p=0.362).ConclusionOTSC therapy appears to be superior to standard treatment with clips when used by trained physicians for selected cases of primary therapy of NVUGIB with high risk of rebleeding. Further studies are necessary with regards to patient selection to identify subgroups benefiting most from OTSC haemostasis.Trial registration numberNCT03331224.

The quality and characteristics of a powder in powder bed fusion processes play a vital role in the quality of additively manufactured components. Its characteristics may influence the process in various ways. This paper presents an investigation highlighting the influence of powder deterioration on the stability of a molten pool in a laser beam powder bed fusion (LB-PBF, selective laser melting) process and its consequences to the physical properties of the alloy, porosity of 3D-printed components and their mechanical properties. The intention in this was to understand powder reuse as a factor playing a role in the formation of porosity in 3D-printed components. Ti6Al4V (15 μm–45 μm) was used as a base material in the form of a fresh powder and a degraded one (reused 12 times). Alloy degradation is described by possible changes in the shape of particles, particle size distribution, chemical composition, surface tension, density and viscosity of the melt. An approach of 3D printing singular lines was applied in order to study the behavior of a molten pool at varying powder bed depths. Single-track cross-sections (STCSs) were described with shape parameters and compared. Furthermore, the influence of the molten pool stability on the final density and mechanical properties of a material was discussed. Electromagnetic levitation (EML) was used to measure surface tension and the density of the melt using pieces of printed samples. It was found that the powder degradation influences the mechanical properties of a printed material by destabilizing the pool of molten metal during printing operation by facilitating the axial flow on the melt along the melt track axis. Additionally, the observed axial flow was found to facilitate a localized lack of fusion between concurrent layers. It was also found that the surface tension and density of the melt are only impacted marginally or not at all by increased oxygen content, yet a difference in the temperature dependence of the surface tension was observed.

Background Conventional endoscopic resection of lesions affecting the appendiceal orifice is difficult. Endoscopic full-thickness resection (EFTR) is a novel technique in interventional endoscopy. As EFTR near the appendiceal orifice is associated with a subtotal appendectomy, it remains unclear whether the risk of developing appendicitis is increased. We conducted a retrospective analysis of lesions involving the appendiceal orifice treated by EFTR. Methods This was a multicenter retrospective analysis of patients (n = 50) treated with EFTR for lesions involving the appendiceal orifice between 2014 and 2019. The objective was to evaluate the occurrence of appendicitis. Results Acute appendicitis occurred in seven patients (14 %) during follow-up. Conservative treatment was sufficient in four cases, and three patients underwent appendectomy. Conclusions EFTR of lesions involving the appendiceal orifice may be associated with an imminent risk of developing appendicitis and a consecutive need for appendectomy. Patients should be informed about this specific risk prior to resection. It is unclear why some patients develop appendicitis while the majority remains asymptomatic.

Background and study aims TC-325 (Hemospray, Cook Medical) is a powder agent for endoscopic hemostasis in patients with upper gastrointestinal bleeding (UGIB). Although most publications are based on case-reports and retrospective studies, data on efficacy are promising. Here we report our experience with TC-325 for diffuse or refractory UGIB. Patients and methods Data on patients receiving TC-325 for endoscopic hemostasis from November 2013 to February 2017 at our center were analyzed retrospectively. Primary endpoints were technical success (successful immediate hemostasis) and clinical success (effective hemostasis and no recurrent bleeding). Secondary endpoints were recurrent bleeding within 3 and 7 days, hospital mortality and TC-325 associated complications. TC-325 was used for bleeding not amenable to standard endoscopic treatment (e. g. diffuse bleeding) or as salvage therapy after failure of conventional methods Results Fifty-two patients received TC-325 treatment. Most of the patients were treated for peptic ulcer bleeding (18/52 patients, 34.6 %) and post-interventional bleeding (13/52 patients, 25 %). Hemospray was used in 23/52 (44.2 %) patients as monotherapy and in 29/52 (55.8 %) patients as a salvage therapy. Application of the powder on the bleeding source was successful in all patients with no therapy-related adverse events (AEs). Immediate hemostasis was achieved in 51/52 (98.1 %) patients. Recurrent bleeding within 3 and 7 days was observed in 22/51 and 25/51 patients respectively (43.1 % and 49 %). The overall clinical success was 56.9 % on day 3 and 51 % on day 7. Total mortality was 15.4 % (8 patients), bleeding associated mortality was 3.8 % (2 patients). There were no therapy-related AEs. Conclusions TC-325 showed a high technical success rate as monotherapy for bleeding sources not amenable to standard methods or as an “add-on” therapy after unsuccessful hemostasis. However, rebleeding was frequent in this cohort and further studies are warranted to exactly define a treatment algorithm for TC-325 use.

Temporary placement of removable, fully covered, self-expandable metal stents (fcSEMS) for treatment of benign biliary strictures (BBS) has been reported to be effective. However, the optimal extraction time point remains unclear and stent migration has been a major concern.The objective of this study was to evaluate the efficacy and safety of this treatment modality using an fcSEMS with a special antimigration design and prolonged stent indwell time.We performed a prospective, single-arm study at six tertiary care centers in Europe. Patients with BBS underwent endoscopic or percutaneous implantation of an fcSEMS (GORE® VIABIL® Biliary Endoprosthesis, W.L. GoreAssociates, Flagstaff, AZ, USA). The devices were scheduled to be removed nine months later, and patients were to return for follow-up for an additional 15 months.Forty-three patients were enrolled in the study. Stricture etiology was chronic pancreatitis in the majority of patients (57.5%). All fcSEMS were placed successfully, either endoscopically (76.7%) or percutaneously (23.3%). Stent migration was observed in two patients (5.2%). Primary patency of the SEMS prior to removal was 73.0%. All attempted stent removals were successful. At removal, stricture was resolved or significantly improved without need for further therapy in 78.9% of patients. Stricture recurrence during a follow-up of two years post-implant was observed in two patients.Temporary placement of the fcSEMS is a feasible, safe and effective treatment for BBS. The design of the device used in this study accounts for very low migration rates and facilitates easy stent retrieval, even after it has been in place for up to 11 months.

BACKGROUND Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world. AIM To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection. METHODS EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC®, Ovesco Endoscopy, Tübingen, Germany). AWC® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp®, Ovesco Endoscopy, Tübingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp® has been shown in a pre-clinical study in domestic pigs. LiftUp® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events. RESULTS Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation. CONCLUSION EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.

Background and Aims Current international guidelines recommend endoscopic resection for T1 colorectal cancer (CRC) with low-risk histology features and oncologic resection for those at high risk of lymphatic metastasis. Exact risk stratification is therefore crucial to avoid under-treatment as well as over-treatment. Endoscopic full-thickness resection (EFTR) has shown to be effective for treatment of non-lifting benign lesions. In this multicenter, retrospective study we aimed to evaluate efficacy, safety, and clinical value of EFTR for early CRC. Methods Records of 1234 patients undergoing EFTR for various indications at 96 centers were screened for eligibility. A total of 156 patients with histologic evidence of adenocarcinoma were identified. This cohort included 64 cases undergoing EFTR after incomplete resection of a malignant polyp (group 1) and 92 non-lifting lesions (group 2). Endpoints of the study were: technical success, R0-resection, adverse events, and successful discrimination of high-risk versus low-risk tumors. Results Technical success was achieved in 144 out of 156 (92.3%). Mean procedural time was 42 minutes. R0 resection was achieved in 112 of 156 (71.8%). Subgroup analysis showed a R0 resection rate of 87.5% in Group 1 and 60.9% in Group 2 (P Conclusions In early colorectal cancer, EFTR is technically feasible and safe. It allows exact histological risk stratification and can avoid surgery for low-risk lesions. Prospective studies are required to further define indications for EFTR in malignant colorectal lesions and to evaluate long-term outcome.

The repeated reuse of excess powder is an essential part of the economics of powder-bed additive manufacturing processes. Although many studies on selective laser melting cover the topics of material properties at the micro- and macroscale, little is known about the influence of the multiple reuse cycles of powder. Titanium alloys, in particular, are sensitive to chemical contamination, especially in the presence of oxygen and hydrogen which can lead to inferior material properties. Furthermore, grain size distribution and form change over time which can have an influence on build quality. In this study, the influence of the chosen powder on the quality and material properties of the widely used titanium alloy Ti6Al4V is investigated with focus on porosity, surface quality, microstructure and tensile strength.

Sufficient bowel preparation is crucial for successful screening and surveillance colonoscopy. However, rates of inadequate preparation are still high. We investigated the effects of reinforced patient education using a smartphone application software (APP) for colonoscopy preparation in participants in a CRC screening program.We performed a prospective, endoscopist-blinded study of 500 patients undergoing split-dose bowel preparation for CRC screening or surveillance colonoscopies at multiple centers in Germany, from November 2017 through January 2019. Participants (n = 500) were given oral and written instructions during their initial appointment and then randomly assigned (1:1) to groups that received reinforced education starting 3 days before the colonoscopy (APP group) or no further education (controls). The primary outcome was quality of bowel preparation according to the Boston bowel preparation scale. Secondary outcomes included polyp and adenoma detection rates, compliance with low-fiber diet, split-dose laxative intake, perceived discomfort from the preparation procedure.The mean Boston bowel preparation scale score was significantly higher in the APP-group (7.6 ± 0.1) than in the control group (6.7 ± 0.1) (P.0001). The percentage of patients with insufficient bowel preparation was significantly lower in the APP group (8%) than in the control group (17%) (P = .0023). The adenoma detection rate was significantly higher in the APP group (35% vs 27% in controls) (P = .0324). Use of the APP was accompanied by a lower level of non-compliance with correct laxative intake (P =.0080) and diet instructions (P = .0089). The APP group reported a lower level of discomfort during preparation (P.0001).In a randomized trial, reinforcing patient education with a smartphone application optimized bowel preparation in the 3 days before colonoscopy, increasing bowel cleanliness, adenoma detection, and compliance in patients undergoing CRC screening or surveillance. ClinicalTrials.gov no: NCT03290157.

Im Rahmen der endoskopischen Resektion von neoplastischen gastrointestinalen Lasionen gehoren die konventionelle Schlingenektomie, die endoskopische Mukosaresektion (EMR) sowie die endoskopische Submukosadissektion (ESD) zu den etablierten Standardverfahren. Sie sind prinzipiell auf oberflachliche mukosal und submukosal gelegene Lasionen begrenzt. Lasionen ohne Lifting-Zeichen oder Lasionen in schwieriger anatomischer Lage konnen mit den Standardverfahren nicht oder nur unter Inkaufnahme einer erhohten Komplikationsrate reseziert werden. Bei Lasionen >2 cm ist die ESD den anderen Verfahren aufgrund der En-bloc-Resektion, anhand derer die vollstandige Abtragung histologisch gut beurteilt werden kann, uberlegen. Sie ist aber insbesondere bei grosen Lasionen technisch anspruchsvoll, zeitaufwendig und mit einer erhohten Komplikationsrate assoziiert. Seit Entwicklung der „over-the-scope clips“ (OTSC) sind Komplikationen wie Blutungen und Perforationen allerdings endoskopisch besser beherrschbar. In den letzten Jahren sind endoskopische Vollwandresektionsverfahren in den Fokus der interventionellen Endoskopie geruckt. Anforderungen an solche Verfahren sind eine einfache Handhabung, eine hohe Patientensicherheit und hohe technische und klinische Erfolgsraten. Seit 2014 ist mit dem „full thickness resection device“ (FTRD) ein minimal-invasives Verfahren zur endoskopischen Vollwandresektion im unteren Gastrointestinaltrakt verfugbar. Es kombiniert die OTSC-Applikation und Schlingenektomie in einem Schritt. Diese Resektionstechnik kann einem ausgewahlten Patientenkollektiv eine chirurgische Therapie ersparen. Im vorliegenden Beitrag werden alle derzeit klinisch einsetzbaren Vollwandresektionstechniken vorgestellt, aufgrund der klinischen Relevanz liegt der Fokus allerdings auf dem FTRD-System.

To determine safety and efficacy of transjugular portal vein recanalization with creation of intrahepatic portosystemic shunt (PVR-TIPS) in patients with chronic non-cirrhotic, non-malignant portal vein thrombosis (PVT).This retrospective study includes 17 consecutive patients with chronic non-cirrhotic PVT (cavernous transformation n = 15). PVR-TIPS was indicated because of variceal bleeding (n = 13), refractory ascites (n = 2), portal biliopathy with recurrent cholangitis (n = 1), or abdominal pain (n = 1). Treatment consisted of a combination of transjugular balloon angioplasty, mechanical thrombectomy, and-depending on extent of residual thrombosis-transjugular intrahepatic portosystemic shunt and additional stenting of the portal venous system.Recanalization was successful in 76.5 % of patients despite cavernous transformation in 88.2 %. Both 1- and 2-year secondary PV and TIPS patency rates were 69.5 %. Procedure-related bleeding complications occurred in 2 patients (intraperitoneal bleeding due to capsule perforation, n = 1; liver hematoma, n = 1) and resolved spontaneously. However, 1 patient died due to subsequent nosocomial pneumonia. During follow-up, 3 patients with TIPS occlusion and PVT recurrence experienced portal hypertensive complications.PVR-TIPS is safe and effective in selected patients with chronic non-cirrhotic PVT. Due to technical complexity and possible complications, it should be performed only in specialized centers with high experience in TIPS procedures.ZIEL: Untersuchung der Sicherheit und Effektivität der transjugulären Pfortaderrekanalisation mit intrahepatischem portosystemischem Shunt (PVR-TIPS) bei Patienten mit chronischer nicht-zirrhotischer, nicht-maligner Pfortaderthrombose (PVT).In diese retrospektive Studie wurden 17 konsekutive Patienten mit chronischer nicht-zirrhotischer PVT (kavernöse Transformation, n = 15) eingeschlossen. Indikationen zur interventionellen Therapie waren Varizenblutung (n = 13), therapierefraktärer Aszites (n = 2), portale Biliopathie mit rezidivierenden Cholangitiden (n = 1) sowie abdominelle Schmerzen (n = 1). Die interventionelle Therapie bestand aus einer Kombination von transjugulärer Ballonangioplastie, mechanischer Thrombektomie und Anlage eines transjugulären intrahepatischen portosystemischen Shunts (TIPS). Abhängig von der Ausdehnung einer evtl. noch vorhandenen Restthrombose erfolgte ggf. eine zusätzliche Stenteinlage im portalvenösen System.Die Rekanalisation mittels PVR-TIPS war bei 76,5 % der Patienten erfolgreich, obwohl bei 88,2 % eine kavernöse Transformation vorlag. Die sekundären 1- und 2-Jahresoffenheitraten betrugen 69,5 %. Selbstlimitierende Blutungskomplikationen traten bei 2 Patienten auf (intraperitoneale Blutung aufgrund einer Perforation der Leberkapsel, n = 1; Leberhämatom, n = 1). Einer der beiden Patienten verstarb jedoch im Verlauf des Indexaufenthalts aufgrund einer nosokomialen Pneumonie. Während des Follow-Ups entwickelten drei Patienten aufgrund eines PVT-Rezidivs portalhypertensive Komplikationen.PVR-TIPS ist eine sichere und effektive Methode zur Behandlung ausgewählter Patienten mit chronischer nicht-zirrhotischer PVT. Aufgrund der Komplexität des Eingriffs sowie der möglichen Risiken sollte die Methode nur in spezialisierten Zentren mit einer hohen Erfahrung bezüglich TIPS-Prozeduren durchgeführt werden.