Wiedererstellung der Perfusion in den supra-aortalen Ästen durch offenen hybrid Stenting des Aortenbogens für akute Typ A Aortendissektion

Objectives: Acute type A aortic dissection is a lethal condition that requires emergent surgical repair, especially in case of cerebral malperfusion. In this setting, we aimed to investigate perfusion patterns in the aorta and in the supra-aortic vessels after implantation of the Ascyrus Medical Dissection Stent (AMDS). Methods: 16 consecutive patients presenting acute type A aortic dissection with involvement of at least one supra-aortic vessel treated with the AMDS device were retrospectively screened from our institutional database. Dissection anatomy, true and false lumen perfusion were investigated in pre- and postoperative computer tomography, using standardized centerline reconstructions. To perform an objective perfusion evaluation, the true lumen area was indexed to the entire vessel area and paired sample t-test was used to assess relevant differences prior and after surgery. Results: AMDS implantation triggered a significant improvement of true lumen perfusion in the supra-aortic vessels and descending aorta. Innominate, right and left common carotid arteries indexed true lumen increased by 72%, 112% and 30%, respectively. Device implantation induced complete resolution of every total occlusion in both common carotid arteries. After surgery, proximal- and mid-descending aorta experienced a 78% and 48% improvement in indexed true lumen area, respectively. Conclusions: hybrid arch repair using the AMDS shows promising results in terms of vascular remodeling after surgery for acute type A aortic dissection. A standardized comparison of imaging prior and after the operation demonstrated significant improvement of true lumen perfusion and complete elimination of vessel occlusions in the supra-aortic vessels. Further investigation in a larger cohort of patients is mandatory as well as the comparison with an isolated hemiarch repair.Ziele: Die akute Aortendissektion Typ A ist eine tödliche Erkrankung der Hauptschlagader, die eine sofortige chirurgische Versorgung benötigt, insbesondere im Fall einer zerebralen Malperfusion. Die vorliegende Analyse zielt darauf ab, den nicht gecoverten Ascyrus Medical Dissection Stent (AMDS) im Hinblick auf die Perfusion der supra-aortalen Gefäße nach einer Operation für akuten Aortendissektion Typ A zu untersuchen. Methode: Zwischen 2017 und 2020 wurden 16 konsekutive AMDS-Implantationen bei Patienten mit Dissektion oder Totalverschluss von mindestens einem supra-aortalen Gefäß retrospektiv analysiert. Prä- und postoperative Computertomografien wurden standardisiert hinsichtlich der wahren, falschen und gesamten Lumenfläche unter Verwendung von Mittellinienrekonstruktionen ausgewertet. Die wahre Lumenfläche wurde auf die gesamte Gefäßfläche bezogen, und ihre Veränderungen vor und nach der AMDS-Implantation wurden mit einem t-Test für gepaarte Stichproben verglichen. Ergebnisse: Die AMDS-Implantation führte zu einer signifikanten Verbesserung der wharen Lumen Perfusion in den supra-aortalen Gefäßen und in der absteigenden Aorta. Das wahre Lumen der Arteria Anonima, der rechten und linken Arteria Carotis communis nahm jeweils um 72 %, 112 % bzw. 30 % zu. Die Implantation des Stents führte zu einer vollständigen Auflösung jedes Totalverschlusses in beiden Karotisarterien. Nach der Operation verbesserte sich das indizierte wahre Lumen der proximalen und der mittleren Aorta descendens um 78 % bzw. 48 %. Schlussfolgerungen: Die Hybridbogenreparatur mit dem AMDS-Device führt zu günstigen Ergebnissen bei der chirurgischen Behandlung akuten Aortendissektionen Typ A. Nach einem standardisierten Vergleich der Bildgebung vor und nach der Operation konnte eine signifikante Vergrößerung der wahren Lumenfläche und eine vollständige Rückbildung der total verschlossenen supra-aortalen Äste nachgewiesen werden. Diese vorläufigen Ergebnisse zur positiven Gefäß-Remodelling nach AMDS-Implantation müssen in zahlreicheren Kohorten bestätigt werden, möglicherweise nach einem Vergleich mit einer Teilbogen-Reparatur allein

Early earthquake detection capabilities of different types of future-generation gravity gradiometers

Since gravity propagates at the speed of light, gravity perturbations induced by earthquake deformation have the potential to enable faster alerts than the current earthquake early warning systems based on seismic waves. Additionally, for large earthquakes (M_w > 8), gravity signals may allow for a more reliable magnitude estimation than seismic-based methods. Prompt elastogravity signals induced by earthquakes of magnitude larger than 7.9 have been previously detected with seismic arrays and superconducting gravimeters. For smaller earthquakes, down to M_w ≃ 7, it has been proposed that detection should be based on measurements of the gradient of the gravitational field, in order to mitigate seismic vibration noise and to avoid the canceling effect of the ground motions induced by gravity signals. Here we simulate the five independent components of the gravity gradient signals induced by earthquakes of different focal mechanisms. We study their spatial amplitude distribution to determine what kind of detectors is preferred (which components of the gravity gradient are more informative), how detectors should be arranged, and how earthquake source parameters can be estimated. The results show that early earthquake detections, within 10 seconds of the rupture onset, using only the horizontal gravity strain components are achievable up to about 140 km distance from the epicenter. Depending on the earthquake focal mechanism and on the detector location, additional measurement of the vertical gravity strain components can enhance the detectable range by 10–20 km. These results are essential for the design of gravity-based earthquake early warning systems

Case Report: Successful endovascular treatment of acute type A aortic dissection

Introduction: Open surgical repair remains the current gold standard for the treatment of acute type A aortic dissection. However, especially elderly patients with relevant comorbidities who are deemed unfit for open surgery may benefit from a minimally invasive endovascular approach. Methods: We report a case of an 80-year-old male with retrograde acute type A aortic dissection and peripheral malperfusion after receiving thoracic endovascular aortic repair due to thoracic aortic aneurysm. Our individualized endovascular approach consisted of left carotid-subclavian bypass, proximal extension of thoracic endovascular aortic repair using a covered stent graft and a single covered stent graft for the ascending aorta in combination with an uncovered stent for the aortic arch. Results: Postoperative computed tomographic angiography demonstrated excellent outcome with no signs of endoleak or patent false lumen. Follow-up after 3.5 years showed a stable result with no signs of stent failure or dissection progress. No aortic re-interventions were needed in the further course. Discussion: An individualized endovascular approach may be justified for acute type A aortic dissection in elderly patients with high surgical risk if performed in specialized aortic centers. Additional short-length stent graft devices are needed to address the anatomical challenges of the ascending aorta. For enhanced remodeling of the dissected aorta, the use of an additional uncovered stent may be advisable

Early earthquake detection capabilities of different types of future-generation gravity gradiometers

International audienceSUMMARY Since gravity changes propagate at the speed of light, gravity perturbations induced by earthquake deformation have the potential to enable faster alerts than the current earthquake early warning systems based on seismic waves. Additionally, for large earthquakes (Mw > 8), gravity signals may allow for a more reliable magnitude estimation than seismic-based methods. Prompt elastogravity signals induced by earthquakes of magnitude larger than 7.9 have been previously detected with seismic arrays and superconducting gravimeters. For smaller earthquakes, down to Mw ≃ 7, it has been proposed that detection should be based on measurements of the gradient of the gravitational field, in order to mitigate seismic vibration noise and to avoid the cancelling effect of the ground motions induced by gravity signals. Here we simulate the five independent components of the gravity gradient signals induced by earthquakes of different focal mechanisms. We study their spatial amplitude distribution to determine what kind of detectors is preferred (which components of the gravity gradient are more informative), how detectors should be arranged and how earthquake source parameters can be estimated. The results show that early earthquake detections, within 10 s of the rupture onset, using only the horizontal gravity strain components are achievable up to about 140 km distance from the epicentre. Depending on the earthquake focal mechanism and on the detector location, additional measurement of the vertical gravity strain components can enhance the detectable range by 10–20 km. These results are essential for the design of gravity-based earthquake early warning systems

Human amniotic membrane: an improvement in the treatment of Medication-related osteonecrosis of the jaw (MRONJ)? A case\u2013control study

The aim of this article is to report the results obtained by the use of HAM in surgical wound healing and the reduction of relapse in patients affected by Medication-related osteonecrosis of the jaw (MRONJ).The study involved patients with the diagnosis of MRONJ, surgically treated between October 2016 and April 2019, in a case-control setting. Enrolled patients were randomly divided into 2 groups. One group will be treated with resective surgery and with the insertion of HAM patch (Group A), while the second group had been treated exclusively with resective surgery (Group B).The patients underwent MRONJ surgical treatment with the placement of amniotic membrane patches at the wound site. Data regarding the long-term complications/functions were evaluated at 3, 6, 12, and 24months after surgery. Pain measurements were performed before the intervention (T0), 7(T1) and 30(T2) days after surgery. 49 patients were included in the study. 2 patients of GROUP A after 30days since they were surgically treated showed persistent bone exposure. 5 patients of group B demonstrated a lack of healing of the surgical wound with the persistence of bone exposed to 30days after surgery. Statistical analysis ruled out any difference in OUTCOME (relapse) between GROUP A and B (p=0.23). However, the Fisher test highlighted a significant difference between the use of HAM and only surgical treatment in pain at rest (p=0.032). The use of amniotic membrane implement the patient's quality of life and reduce pain perception. has a learning curve that is fast enough to justify its routine use

Les signaux d'élasticité rapide (PEGS) : Capacités de détection et limites des sismomètres à très haut débit

Prompt ElastoGravity Signals (PEGS) come from gravitational disturbances associated with the redistribution of the mass carried by the elastic waves. As such, they are the first deformation signals observable after an earthquake. Today, PEGS have been clearly observed with (very) broadband seismometers for 6 large magnitude earthquakes (Mw >7.8), and can be accurately modeled by several approaches. After the summary of the main observational results of the last two years, this poster shows concretely when detection can or cannot be performed with seismometers, based on the characteristics of the least noisy very wideband stations (Geoscope, Global Seismic Network, FNET). This poster was presented at the Résif Scientific and Technical Meetings held in Biarritz in November 2019. Résif is a national research infrastructure dedicated to the observation and understanding of the Earth's internal structure and dynamics. Résif is based on high technology observation networks, composed of seismological, geodetic and gravimetric instruments deployed in a dense manner throughout the French territory. The data collected allow the study of ground deformation, surface and deep structures, local and global seismicity and natural hazards, particularly seismic, on the French territory with a high spatio-temporal resolution. Résif is integrated into the European (EPOS - European Plate Observing System) and worldwide instruments that allow to image the Earth's interior in its entirety and to study numerous natural phenomena.Les signaux d'élasticité rapide (PEGS) proviennent des perturbations gravitationnelles associées à la redistribution de la masse transportée par les ondes élastiques. En tant que tels, ils sont les premiers signaux de déformation observables après un tremblement de terre. Aujourd'hui, les PEGS ont été clairement observés avec des sismomètres (à très) large bande pour 6 séismes de grande magnitude (Mw >7,8), et peuvent être modélisés avec précision par plusieurs approches. Après le résumé des principaux résultats d'observation de ces deux dernières années, ce poster montre concrètement quand la détection peut ou non être réalisée avec des sismomètres, en se basant sur les caractéristiques des stations à très large bande les moins bruyantes (Géoscope, Réseau sismique mondial, FNET). Ce poster a été présenté lors des Rencontres scientifiques et techniques Résif qui se sont déroulées à Biarritz en novembre 2019. Résif est une infrastructure de recherche nationale dédiée à l’observation et la compréhension de la structure et de la dynamique Terre interne. Résif se base sur des réseaux d’observation de haut niveau technologique, composés d’instruments sismologiques, géodésiques et gravimétriques déployés de manière dense sur tout le territoire français. Les données recueillies permettent d’étudier avec une haute résolution spatio-temporelle la déformation du sol, les structures superficielles et profondes, la sismicité à l’échelle locale et globale et les aléas naturels, et plus particulièrement sismiques, sur le territoire français. Résif s’intègre aux dispositifs européens (EPOS - European Plate Observing System) et mondiaux d’instruments permettant d’imager l’intérieur de la Terre dans sa globalité et d’étudier de nombreux phénomènes naturels

Human Amniotic Membrane Positioning in the Surgical Treatment of Temporomandibular Joint Degenerative Disorder

Background. Temporomandibular joint (TMJ) arthritis is a degenerative pathology that may cause pain and dysfunction. Nonsurgical therapy is the traditional treatment of TMJ diseases but if ineffective, TMJ surgery can be performed and may include arthroplasty with interposition of autograft. The encouraging results reported with the use of human amniotic membrane (HAM) in different surgical fields have highlighted its potential, but approaches providing the positioning of HAM within the intra-articular space of arthritic TMJs have never been investigated. Case Presentation. A 48-year-old woman was presented with limited mouth opening and pain with palpation at the left joint. A severe TMJ degeneration was diagnosed, and a surgical treatment was necessary. In the present case report, the authors describe the application of a cryopreserved HAM patch within the joint space as a disc-replacing film during major surgeries for discectomy and arthroplasty. Three months after the intervention, the patient reported an overall improvement in chewing efficiency as well as the absence of pain. Conclusions. According to the regenerative effects of HAM, the design of trials on the topic should be encouraged for its possible inclusion within the field of TMJ disease practice

Comment on “Earthquake-induced prompt gravity signals identified in dense array data in Japan” by Kimura et al.

International audienceA recent work by Kimura et al. (Earth Planets Space 71:27, 2019. https://doi.org/10.1186/s40623-019-1006-x ) (hereafter referred to as K19) claims to provide the first observational constraints on the prompt elastogravity signals (PEGS) induced by an earthquake. To make their claim, the authors argue that the observations shown in Vallée et al. (Science 358:1164–1168, 2017. https://doi.org/10.1126/science.aao0746 ) (hereafter referred to as V17) are spurious and their modeling inaccurate. Here we show that K19’s claim is invalid because it is based on flawed data processing. In fact, K19’s analysis involves an incomplete correction of the instrument response of broadband seismic sensors, which essentially dismisses low-frequency components of the data that are critical for the detection of intrinsically low-frequency signals such as PEGS. As a direct consequence, signals are much more difficult to observe than in V17, where the low part of the signal spectrum is carefully taken into account. This deficient data processing also explains why the signal amplitude reported by K19 after stacking data from multiple stations is lower than the individual signals reported by V17. Moreover, failing to take appropriate measures of data quality control, K19 used signals from low-quality sensors to call into question the signals detected by high-quality sensors. Finally, K19 use an inadequate simulation approach to model PEGS, in which the important effect of the ground acceleration induced by gravity changes is ignored. In summary, K19 do not show any viable arguments to question the observations and modeling of PEGS presented in V17

Observations and modeling of the elastogravity signals preceding direct seismic waves

International audienceAfter an earthquake, the earliest deformation signals are not expected to be carried by the fastest (P) elastic waves but by the speed-of-light changes of the gravitational field. However, these perturbations are weak and, so far, their detection has not been accurate enough to fully understand their origins and to use them for a highly valuable rapid estimate of the earthquake magnitude. We show that gravity perturbations are particularly well observed with broadband seismometers at distances between 1000 and 2000 kilometers from the source of the 2011, moment magnitude 9.1, Tohoku earthquake. We can accurately model them by a new formalism, taking into account both the gravity changes and the gravity-induced motion. These prompt elastogravity signals open the window for minute time-scale magnitude determination for great earthquakes