The Transaxillary Approach via Prosthetic Conduit for Transcatheter Aortic Valve Replacement With the New-Generation Balloon-Expandable Valves in Patients With Severe Peripheral Artery Disease

Background: The left subclavian artery (LSA) is an infrequently used alternative access route for patients with severe peripheral artery disease (PAD) in patients who underwent transcatheter aortic valve replacement (TAVR). We report a new endovascular approach for TAVR combining an axillary prosthetic conduit-based access technique with new-generation balloon-expandable TAVR prostheses.Methods and Results: Between January 2020 and December 2020, 251 patients underwent TAVR at the West German Heart and Vascular Center. Of these, 10 patients (3.9%) were deemed to be treated optimally by direct surgical exposure of the left or right axillary artery via a surgically adapted prosthetic conduit. All procedures were performed under general anesthesia. One procedural stroke occurred due to severe calcification of the aortic arch. No specific complications of the subclavian access site (vessel rupture, vertebral, or internal mammary ischemia) were reported. Two minor bleedings from the access site could be treated conservatively. No surgical revision was necessary.Conclusion: The axillary prosthetic conduit-based access technique using new-generation balloon-expandable valves allows safe and successful TAVR in a subgroup of patients with a high risk of procedural complications due to severe peripheral vascular disease. Considering the increasing number of patients referred for TAVR, this approach could represent an alternative for patients with limited access sites.

A new iteration for the single-access large-bore technique during impella supported complex and high-risk coronary intervention: a case report

BACKGROUND Complex and high-risk coronary intervention (CHIP-PCI) and PCI in cardiogenic shock complicating acute coronary syndrome is increasingly performed under mechanical circulatory support—so called protected PCI. Among the available options, Impella CP heart pump (ABIOMED) is percutaneously inserted over the femoral artery and typically requires a second arterial access to perform PCI, which further enhances the risk of vascular and bleeding complications. The single-access technique allows Impella CP placement and PCI performance through the same vascular access. When a 7-french system is desirable, only a long and entirely hydrophilic coated sheath has been previously used, which is not available in Europe. CASE SUMMARY A 85-year-old patient admitted with NSTE-ACS, severely reduced left ventricular function and three-vessel coronary artery disease underwent single access CHIP-PCI under Impella CP support. After a failed attempt to insert a standard 7-french long femoral sheath alongside the Impella catheter, we successfully introduced a 7.5-french sheathless guiding catheter and delivered the planned percutaneous treatment with the benefits conferred by a 7-french—rather than 6 - lumen catheter, without the need for an additional arterial access. DISCUSSION This is, to the best of our knowledge, the first case of CHIP-PCI performed under Impella support utilizing the single-access technique with a 7.5-french sheathless guiding catheter. Beyond advantages of the single-access technique in sparing time and avoiding vascular complications associated with gaining a second arterial access, the lower outer diameter of the sheathless catheter compared with standard 7-french sheaths may allow improved limb perfusion and lower chance of interference with the impella CP catheter.

Digital Planning on Guided Endodontics Technology

The aim of this review is to discuss the digital planning and the use of guided technology in Endodontics. The complexity of the root canals anatomy and the challenges in the microorganism’s control represent risk factors for failure after the infected root canal’s treatment. Scientific improvements associated with technological advances have enabled better predictability of therapeutic procedures results. The development of efficient and modern devices provided safer root canal treatments, with shorter clinical visits and greater patient comfort. Digital endodontics incorporated different tools and developed its own, advancing even further in resolving complex cases. The faithful copy of the internal anatomy provided by the advancement of CBCT devices and software’s, associated with the digital resources of 3D planning and printing, enabled the advent of guided endodontics. This technique is used at different stages of endodontic treatment, with specific indications and greater result predictability. Therefore, this study critically reviewed the potential clinical application of this guided access technique, and the operative steps for its safe performance in managing complex endodontic cases. The main indications are accessing calcified root canals, performing endodontic surgeries in difficult access areas, removing fiberglass posts, and accessing teeth with developmental anomalies. In summary, guided endodontics has been a precise strategy, effective, safe, and clinically applicable. This procedure represents incorporating technological resources and digital planning in the Endodontist clinical practice, increasing predictability to complex cases.

Optimization of LoRaWAN Access control

Long Range Wide Area Network (LoRaWAN) enables flexible long-range communication with low power consumption which is suitable for IoT applications. LoRaWAN’s performance is due on the one hand to its spreading factor modulation allowing the spread out of communication between end-devices and gateways on different frequency channels and data rates. And on the other hand, to the ability to manage for each node its data rate and its transmission power thanks to the adaptive data rate (ADR) scheme in order to increase the overall network capacity and to maximize the battery life of end devices. However, because of the Aloha access technique adopted by LoRaWAN, the risk of using the same data rate on the same channel is not negligible. Despite the limitation of the duty cycle for each node, the risk of collision is high with the increase of the number of end devices which degrades the LoRaWAN’s performance. In this context, our paper proposes different approaches to improve the performance of LoRaWAN. The first contribution consists in improving the ADR technique to meet the characteristics of a mobile environment. The new mechanism proposed, called VHMM-based E-ADR, consists of adapting the data rate of the end-device according to its position. The second contribution consists in better managing the use of the duty cycle by proposing a dynamic sharing mechanism (Dynamic Duty-Cycle). The last contribution consists in proposing a deterministic access technique to replace Aloha. Our experimental study has shown that our proposals give better results in terms of Packet Delivery Ratio (PDR) and energy consumption than basic LoRaWAN in a mobile environment.

Is Satellite Ahead of Terrestrial in Deploying NOMA for Massive Machine-Type Communications?

Non-orthogonal multiple access (NOMA) technologies are considered key technologies for terrestrial 5G massive machine-type communications (mMTC) applications. It is less known that NOMA techniques were pioneered about ten years ago in the satellite domain to match the growing demand for mMTC services. This paper presents the key features of the first NOMA-based satellite network, presenting not only the underlying technical solutions and measured performance but also the related deployment over the Eutelsat satellite fleet. In particular, we describe the specific ground segment developments for the user terminals and the gateway station. It is shown that the developed solution, based on an Enhanced Spread ALOHA random access technique, achieves an unprecedented throughput, scalability and service cost and is well matched to several mMTC satellite use cases. The ongoing R&D lines covering both the ground segment capabilities enhancement and the extension to satellite on-board packet demodulation are also outlined. These pioneering NOMA satellite technology developments and in-the-field deployments open up the possibility of developing and exploiting 5G mMTC satellite- and terrestrial-based systems in a synergic and interoperable architecture.