Machine learning is revolutionizing the way multimedia information is processed and transmitted to users. After intensive and powerful training, some impressive efficiency/accuracy improvements have been made all over the transmission pipeline. For example, the high model capacity of the learning-based architectures enables us to accurately model the image and video behavior such that tremendous compression gains can be achieved. Similarly, error concealment, streaming strategy or even user perception modeling have widely benefited from the recent learning-oriented developments. However, learning-based algorithms often imply drastic changes to the way data are represented or consumed, meaning that the overall pipeline can be affected even though a subpart of it is optimized. In this paper, we review the recent major advances that have been proposed all across the transmission chain, and we discuss their potential impact and the research challenges that they raise. During the past few years, we have witnessed an unprecedented change in the way multimedia data are generated and consumed as well as the wide adaptation of image/video in an increasing number of driving applications. For example, Augmented Reality/Virtual Reality/eXtended Reality (AR/VR/XR) is now widely used in education, entertainment, military training, and so forth, although this was considered a utopia only a few years ago. AR/VR/XR systems have transformed the way we interact with the data and will soon become the main means of communication. Image and video data in various formats is an essential component of numerous future use cases. An important example is intelligent transportation systems (ITS), where visual sensors are installed in vehicles to improve safety through autonomous driving. Another example is visual communication systems that are commonly deployed in smart cities mainly for surveillance, improving the quality of life, and environmental monitoring. The above use cases face unique challenges as they involve not only the communication of huge amounts of data, for example, an intelligent vehicle may require the communication of 750 MB of data per second , with thThese undergoing transformative changes have been the driving force of research in both multimedia coding and multimedia communication. This has led to new video coding standards for encoding visual data for humans  or machines (MPEG activity on Video Coding for Machines), novel multimedia formats like point clouds, and support of higher resolutions by the latest displays . Various quality of experience (QoE) metrics  have been proposed considering not only the quality of the delivered videos but also parameters such as frame skipping, stalling, and so forth, and the fact that consumers may request the same data but consume them differently. The realization that consumers of visual data can be machines has initiated discussion regarding the definition of task-oriented quality metrics. Since end-users’ demands for multimedia content are diverse, and users interact with the content differently, multimedia communication systems consider users’ behavior and employ cloud/edge/fog/device caching and computation facilities to allow content reuse. The extremely tight latency requirements of the latest multimedia application render impossible having retransmission mechanisms (ARQ) or access to accurate channel estimations. The joint consideration of source and coding has been revisited to design systems that meet the expectations of future multimedia coding and communication systems. These landscaping changes result in complex decision-making problems that conventional optimization methods cannot solve. Further, they are closely related to resource provisioning and the prediction of future trends. Therefore, they naturally call for defining machine learning-based systems that can address the challenges future multimedia coding and communication systems face.Nowadays, machine learning (ML) is commonly used in multimedia communication systems. Machine learning-based coding for images  and videAlthough machine learning-based multimedia communication and coding systems achieve significant gains in comparison to conventional systems, the main sources of suboptimality are that: (i) these research areas have been studied and developed in a fragmented way; (ii) coding and communication frameworks remain human-centric while an increasing number of applications are machine-centric; (iii) interactivity is not fully taken into account when designing an end-to-end multimedia communication system; (iv) machine learning-based image/video coding systems still rely on entropy coding, which compromises error-resilient properties and complicates the transport protocols; (v) the multimedia delivery systems have been optimized considering the structure of the bitstream generated by conventional image/video coders and, hence, perform suboptimally when used to transport bitstreams generated by machine learning-based image/video coding systems; and, (vi) the latest use cases, for example, ITS, AR/VR/XR, and so forth, have ultra-low latency requirements that cannot be met by optimizing a part of the ecosystem separately. In this survey, we advocate for the need for machine learning-enabled end-to-end multimedia coding and communication systems that consider both human and machine users that actively interact with the content.In the following, in A high-level representation of a multimedia coding and communication system is depicted in After source coding, the multimedia data can be either transmitted over wireless or wired connections. For wireless transmission, the data are protected by means of channel coding such as Turbo codes , LDPC coThe delivery of the multimedia bitstreams can be facilitated by edge caching  and clouAt the receiver end, the reverse procedure is followed to recover the transmitted multimedia data. Hence, in case of wireless transmission, the received information is first demodulated and then is channel decoded. To cope with remaining errors after channel coding, the video decoders activate error concealment, which aims at masking the bit errors and erasures by exploiting temporal and spatial redundancy. Another critical video coding tool that is activated to improve the quality of the decoded videos is loop filtering that aims at combating blocking artifacts occurring at the borders of the coding blocks. As the packets may arrive at the receiver out of order due to erasures, the video codecs resynchronize the packets respecting the playback timestamps and may request retransmission of packets that did not reach their destination. Packet rebuffering depends on the affordable time to display the information. The quality of the transmitted data is measured using QoE metrics such as PSNR, SSIM, MOS, Video Multi-method Assessment Fusion (VMAF) ,37 for tMultimedia communication efficiency has constantly improved over the last decades, due to intensive research efforts and new hardware designs. However, several key aspects of the multimedia processing pipeline still rely on hypotheses or models that are too simple. As an example, the aforementioned DCT used in most of image/video coders is optimal when the pixels of the image follow some given distributions  that isf, based on a deep neural network architecture. The obtained latent vector g. In such a system, the goal is to obtain a binary vector The recent arrival of learning-based solutions in the field of image compression has kept its promises in terms of performance. It is nowadays proven that end-to-end neural networks are able to beat the most performing image compression standards such as JPEG , JPEG 20thors in  propose thors in  have buithors in ,47,48, tthors in ,50.For video compression, the benefits of learning-based solutions have been less immediate, mostly because temporal motion is still not accurately modeled by neural network architectures. Naturally, deep neural networks (DNNs) can be used to assist the complex encoding/decoding operations performed by the standard video coders, or to post-process the decoded video ,52. EntiLearning-based approaches have also been explored to compress other types of multimedia contents, such as 360-degree images , 3D poinTo summarize, learning-based approaches reach groundbreaking compression gains and further impressive coding efficiency can be expected in the coming years. However, deep learning architectures remain heavy and sometimes uncontrollable. Some recent works such as  have focCommonly, the communication of the video data happens over error-prone channels such as Binary Symmetric Channels (BSC), Binary Erasure Channels (BCE), and Additive White Gaussian Noise (AWGN) channels, which may lead to corrupted frames, stalled frames, error propagation, etc. and, eventually, degradation of users’ quality of experience. In order to avoid such QoE degradation, channel coding is used to protect the communicated video data. There exist many efficient channel codes like Low Density Parity Check (LDPC) codes , Turbo cThe challenges above triggered significant research in redesigning channel encoding/decoding processes so that the decoding performance is maintained high for short and medium codeblock lengths, and both the decoding complexity and the decoding delay are greatly reduced. To this aim, machine learning has been proposed for channel encoding ,67,68, cThe design of LDPC codes is usually done using EXIT charts or density evolution, however for short codeblock lengths, the assumptions made by these methods do not hold anymore. This fueled the research on designing well-performing channel codes for the non-asymptotic case. In , a conceMachine learning-based channel decoding is proposed to reduce the decoding complexity and improve the decoding performance of High-Density Parity Check (HDPC) codes for medium to short codeblock lengths. Replacing the belief propagation decoder used by HPDC (and LDPC) decoder with a decoder based on neural networks, known as neural belief propagation, has been first presented in ,73,74. IThe joint channel encoding and decoding design is proposed in  to improError concealment is a key component of video communication systems, as the communication is done over error-prone channels that introduce errors to the received bitstream. It aims at localizing the effect of an error and conceal it by exploiting temporal and spatial redundancy. For more efficient error concealment, tools such as motion copy, motion vector extrapolation, motion estimation at the decoder, exploitation of side information at the decoder, insertion of redundant video frames and redundant slices, intra-macroblock updates, and others can be used . Some ofThere is very limited literature on machine learning-based error concealment tools. Long short-term memory (LSTM) based optical flow prediction is proposed in . This isudied in . To thisMore efficient concealment is achieved when advanced error concealment tools such as the ones we discussed previously are combined with optimized partitioning to coding units (CUs). By partitioning the CUs into smaller blocks that are encoded either in intra or inter mode, more resilient to errors video streams are generated as errors can be localized. Most of the existing coding machine learning-based CU partitioning methods ,86 consiStreaming strategies have been challenged by the heterogeneity and interactivity of users consuming media content. Fetching high-quality media content to any final users, despite their displaying device , available connectivity  and interactivity level  requires large amounts of data to be sent in a real-time communication scenario, pushing connectivity boundaries. This requires multimedia systems to operate at scale, in a personalized manner, remaining bandwidth-tolerant whilst meeting quality and latency criteria. However, inferring the network constraints, user requirements and interactivity (to properly adapt the streaming strategy) is not possible without proper machine learning tools. In the following, we provide an overview of the main machine learning-based video streaming systems used both in wireless and wired streaming and clearly show the advances that machine learning has unlocked within this content.Adaptive streaming over HTTP addresses the increasing and heterogeneous demand for multimedia content over the Internet by offering several encoded versions for each video sequence. Each version (or representation) is characterized by a resolution and a bit rate. Each representation is decomposed into temporal chunks  and then is stored at a server. This means that at the server side, each chunk of a given video is available into multiple encoded versions. The main idea behind this strategy is that different users will have different quality and bandwidth requirements and will download different representations, which is decided by an adaptive bitrate (ABR) algorithm. The selection of the optimal representation for a given user happens at the client side, where the intelligence stands as a form of adaptation logic algorithm. Specifically, a client watching a media content will receive a media presentation description (MPD) file from the server, which contains information about all the available representations for each content. Given this information, the client requests the best set of representations for the current chunk based on the available bandwidth, playback buffer, and so forth. The downloaded representations are stored at the client side buffer, from where the chucks are extracted for decoding and displaying. Requesting the best representations means finding the optimal tradeoff between asking for high-quality content and asking for not-too-high bitrate. While a high-bitrate increases the quality of the decoded media content, it also requires large bandwidth to sustain the download. Should this not be available, the user might encounter into large downloading delay, risking emptying the buffer and experience rebuffing  events, with a negative impact on the quality of experience. The main components of an adaptive streaming over HTTP system are depicted in Machine learning allows us to infer complicated relationships between multiple influential factors  and the bitrate selection decision. Predicting network traffic at the user level is particularly challenging because the traffic characteristics emerge from a complex interaction of user-level and application protocol behavior. Early predictive models were focused on linear ones, such as the autoregressive moving average (ARMA) model  and the Key challenges that are still under investigation in ABR and that can benefit from learning tools are: (i) fairness in sharing resources across users ; (ii) noAlternatively, optimal strategies ,100 explMethodologies that implicitly learn the system model are (deep) reinforcement learning (RL) algorithms, which can be used to automate the selection of representation over time accommodating, in which an optimal mapping between the dynamic states and bitrate selections is learned. The benefits of RL-based ABR algorithms have been shown in several works ,106,107 user-centric optimization. The key intuition is that client, server and CDN should be jointly adjusted given the users’ interactivity. In user-centric systems, highlighting what open challenges are still to be solved.Machine learning plays an even more crucial role in the case of interactive communications, in which the dynamic behavior is related not only to network fluctuations but also to users’ movements. Specifically, interactive users watch only a portion of the entire video content (viewport) as shown in DASH-like video streaming systems permit users to control the adaptation of the video quality based on the encountered channel conditions. However, they face difficulties when are used in a wireless environment where multiple users may have similar demands, as they are designed for point-to-point communication. In wireless environments, it is possible to accommodate multiple users’ requests by a single broadcast or multicast transmission. To this aim, users are grouped based on their requests, which allows serving multiple content requests by a single transmission. Such users grouping is not possible for DASH-like systems, as they cannot exploit the correlation among users’ demands. Further, the emergence of interactive videos like 360-degree videos introduces new challenges as the quality adaptation is made on a tile or viewport basis to save bandwidth resources and meet the strict timing constraints. DASH-like systems cannot exploit videos’ and tiles’ or viewport popularity, and hence they treat each tile as an independent video and deliver only those that are within the requested viewport ,123. ThiFrom the discussion above, it is clear that DASH-like video streaming systems perform suboptimally in wireless environments, as they cannot exploit possible correlations of users’ video content requests. Further, these systems cannot take advantage of broadcasting or multicasting opportunities. This calls for alternative video streaming systems that forecast users’ requests, exploit correlation among video consumption patterns of the users and possible association of users with an access point or base station. As forecasting is central in these systems, machine learning methods have been proposed for both 360-degree video ,130,131 The delivery of 360-degree videos captured by unmanned aerial vehicles (UAVs) to a massive number of VR users is studied in . The oveFor traditional video streaming, motivated by the fact that higher bitrate is not always associated with higher video quality, in  performiThe proliferation of devices capable of displaying high-quality videos fueled an unprecedented change in the way users consume data, with portable devices being used for displaying videos. Nowadays, the time users spend on video distribution platforms such as YouTube Live, Facebook Live, and so forth, has surpassed by far the time spent watching TV. This puts tremendous pressure on the communication infrastructure, and as a response, technologies such as mobile edge caching and computing have become an instrumental part of the complex multimedia delivery ecosystems. 5G and beyond networks are comprised of multiple base stations  with overlapping coverage areas. As users’ demands on video content are not uniform, but a few popular videos attract most of the users’ interest, caching of videos at the base station became an attractive option to reduce the cost of retrieving the videos. Through caching, the number of content requests directly served by distant content servers is greatly reduced. This is very important as the backhaul links the base stations use to access the core network are expensive and have limited capacity. Further, the core network can be easily overwhelmed by the bulk of requests, which may lead to a collapse of the communication infrastructure. This, in turn, can result in high delivery delays that will be devastating for users’ quality of experience.Content placement, that is, deciding what video content to cache at the base stations, is closely associated with content delivery, that is, from where to deliver the video content to the users. This happens as base stations’ coverage areas overlap, while multiple base stations may possess the same content. These problems can be either studied independently or jointly, but treating these problems separately is suboptimal. Cache placement is often solved using heuristic algorithms such as the Least Recently Used (LRU), Least Frequently Used (LFU), and First-in First-out (FIFO). Alternatively, the caching and delivery problem can be cast as a knapsack problem and then be solved using approximation algorithms . These aDifferent machine learning algorithms have been proposed to solve the content placement and update problem at caches (and in some cases the delivery problem), such as Transfer learning ,137, deeMost of the existing caching frameworks treat the data as elastic commodities and thus target to optimize the cache hit rate, which is a measure of the reuse of the cached content. Though optimizing cache hit rate can be efficient for file downloading, it is not appropriate for video streaming. This is because it cannot capture critical parameters for video communication such as the content importance and QoE metrics such as video stalling, smoothness, among others, and the relations among the users who consume the content. The latter is considered in ,137 wherMore recently, new types of videos, such as 360-degree videos became popular. The emergence of these video types raises new challenges for caching systems. Specifically, they should take into account how the content is consumed by the users . CachingLooking forward, methods such as those proposed ,141,147 Inferring the human perceptual judgment of media content has been the goal of many research works for many decades as it would enable optimizing multimedia services to be QoE-aware/centric ,152. HerQuantifying quality of experience requires the definition of one or more metrics that are specific to the context, and equally important, a formal way of computing the values for these metrics. Only after this, we can measure a human’s level of satisfaction from the respective service or application. One major challenge in the field of quality assessment has been the model inference in the case of no-reference quality assessment, in which no information about the originating content is provided. Before the deep-learning era, hand-crafted features such as DCT, steerable pyramids, etc., were carried out to then build a perceptual model. With the advances of deep learning, automated features extraction has been considered, obtaining reliable semantic features from deep architectures  achieving remarkable efficiency at capturing perceptual image artifacts ,155,156.Learning which of these extracted features play a key role in the human perceptual quality is a second challenge to be addressed. VMAF  proposedAssessing QoE is even more challenging in the case of video content , in whicDespite all the research carried out on ML for QoE, there are still open challenges in assessing human quality in the experienced streaming services. As observed by multiple researchers, QoE goes beyond the pure quality of the played video and hinges on the viewer’s actual viewing experience. Current methods primarily use explicit information such as encoding bitrate, latency and quality variations, stalling, but they do not make use of less explicit yet more complex intra-session  and inter-session relationships . Cross-correlating actions and change of habits among different viewers is also effective in gaining significant insight into human satisfaction of the streaming service, which is still a measure of QoE. Machine learning can indeed help toward this goal. Another important challenge to mention is the bias that comes in training ML model (to extract and fuse features) via subjective tests. As pointed out in recent and very interesting panels  and workNew challenges have emerged when new multimedia formats have been introduced, such as spherical and volumetric contents. The entire compression and streaming chain has been revisited for these formats. It is important to understand the impact of compression and streaming on the quality of spherical and volumetric content . In 168168, a spAn interesting question arising is how the streaming pipeline should be optimized depending on how we consume content. Specifically, lately, we have witnessed two main revolutions in terms of consumption: (i) the final user consuming the content is no more limited to be a human but can be a machine performing a task; (ii) the final user (when human) is able to actively interact with the content, creating a completely new type of service and, hence, streaming pipeline optimization. The first direction is in its infancy and we further comment on this in the following section. Conversely, several studies have already focused on optimizing the streaming pipeline in the case of interactive users, as already mentioned in the previous sections. These efforts however have relied on a key piece of information, which is the behavior of the users during interactive sessions. We refer the reader to many interesting review papers on user’s behavior ,11. Heresaliency map for 360-degree content and using this information in the streaming pipeline [The first efforts at understanding user behavior were focused on inferring the pipeline . The salpipeline , in whicpipeline  has beenpipeline , where apipeline  by predipipeline  and a nepipeline , in whicpipeline  studied pipeline . All thepipeline  proposedpipeline  proposedpipeline ,187,188,field of view trajectory. In this direction, machine learning has helped toward two main directions: (i) to group similar users by using unsupervised tools such as clustering; (ii) to predict future trajectories of users interactivity. Looking at the first direction, detecting viewers who are navigating in a similar way allows the quantitative assessment of user interactivity, and this can improve the accuracy and robustness of predictive algorithm but also allow the personalization of the streaming pipeline. Last, this quantitative assessment can play a key role also in healthcare applications, in which patients can be assessed based on their eye movement when consuming media content [Instead of looking at saliency, we now review works that use machine learning to study users interactivity via  content . Looking content ,191. A c content , where aBeyond users similarity, several works focus on predicting user behaviors via deep learning strategies that learn the non-linear relationship between the future and past trajectories. The prediction is usually adopted for viewport-adaptive adaptation logic, but it can also be used to optimize the rate-allocation at the server side as in ,193,194.The learning-based methods reviewed in Latent vector description of the images/video: as explained in Another important consequence of the latent-based description is that the standard hierarchical description of the bitstream in the Network Abstraction Layer (NAL) is not defined (and not straightforwardly definable), which makes the streaming of such a binary description not compatible with the standard methods . Even though some learning-based coders let the core of their architecture relying on standard codecs (such as in ), futureCoding for machines: the tremendous amount of transmitted images/videos nowadays are simply not meant to be watched by humans, but to be processed by powerful learning-based algorithms for classification, segmentation, post-processing, and so forth  and the users’ interactivity vector (user-centric).Despite the gains achieved so far, most of the existing works exploit the users’ inferred model in one step of the pipeline, limiting the potentiality of user-centric systems. The introduction of machine learning into several parts of the multimedia communication pipeline has shown great potential and has helped to achieve tremendous performance gains compared to conventional non-machine learning-based multimedia communication systems. As a result, machine learning-based components have already replaced parts of the conventional multimedia communication ecosystem. However, besides the performance gains, machine learning faces difficulties when it is used in other parts of the ecosystem due to compatibility issues with legacy multimedia communication systems. For example, the generated image/video bitstreams by machine learning-based codecs cannot be decoded by conventional codecs. Another example is related to the transport of the bitstreams into packets, as typically latent vectors are large in size. Hence, these issues should be resolved before machine learning becomes an essential part of the entire multimedia communication ecosystem. Initial efforts to build machine learning-enabled end-to-end image communication systems showed great performance gains. However, so far, the introduction of machine learning to the entire video communication pipeline is still in its infancy, and efforts have only targeted parts of the pipeline in a fragmented way. This is a necessity as even 5G networks cannot support bandwidth-killing applications based on videos such as XR/AR/VR, which involve the communication of huge amounts of visual data and are characterized by strict delivery deadlines. Moreover, the realization that the vast majority of the communicated video is not intended to be watched by humans calls for jointly studying existing machine learning-based video coding approaches in order to build approaches appropriate for both machine-oriented and human-centric systems. Towards this goal, machine learning will be instrumental in finding the optimal tradeoff between content-centric and human-centric objectives.


The hybrid surgical concept for the treatment of brain arteriovenous malformations (AVMs) with associated intracranial aneurysms (IAs) is still not widely practiced. Concomitant occurrence of AVMs with IAs is common. Subarachnoid hemorrhage (SAH) as a result of AVM or IA rupture is often associated with these dual pathological phenomena. We present a case of concomitant occurrence of AVMs and IAs that was successfully treated using the hybrid operation concept.A 62-year-old man presented with sudden onset of severe headache, dizziness, nausea, and vomiting for 4 hours.Computed tomography revealed SAH and a hematoma in the right frontal lobe. A computed tomographic angiogram also revealed a right frontal AVM with 3 IAs.We used a hybrid operating room to successfully treat both AVMs and IAs.Two years of follow-up showed that the patients were well and performed their daily duties.The hybrid operating room is an innovative, safe, and effective method for the treatment of AVMs with associated IAs, particularly high-grade AVMs and IAs with hemorrhage or SAH. Patients with concomitant AVMs and IAs have the highest chance of hemorrhage compared with those with AVM or IAs alone. This combined treatment option is currently the most appropriate for concomitant AVMs and IAs.–5The concept of hybrid surgery for the treatment of brain arteriovenous malformations (AVMs) with associated intracranial aneurysms (IAs) is still not widely practiced.–8 Patients with concomitant AVM and IA often have a higher chance of hemorrhage as a result of either AVM or IA rupture, although the precise risk is unclear. AVMs with associated IAs often originate from the feeding artery or within a proper AVM.,7 The concomitant occurrence of these lesions is most likely based on a combination of congenital factors as well as augmented flow dynamics of the AVM.,8,10 IAs that concomitantly occur with AVMs are categorized into arterial aneurysms  or venous aneurysms  based on their relationships with the AVM nidus.IAs are detected in 7.5% to 23.5% of patients with AVMs.,7 Clinically, most patients with concomitant lesions are asymptomatic. Symptomatic patients often present with intracranial hemorrhage. These lesions are best detected with computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography (DSA). Therefore, we present a rare case of concomitant occurrence of IAs and AVMs that we successfully treated using the hybrid operation concept.The natural history of these concomitant lesions and appropriate treatment approaches are not yet well defined because the pathophysiology of the distinctive IA categories is poorly understood.2A 62-year-old man presented with sudden onset of severe headache, dizziness, nausea, and vomiting for 4 hours prior to his admission to our neurosurgery department. He had no history of hypertension or diabetes mellitus. A general physical examination on admission did not yield much results. The neurological examination results were unremarkable. The Glasgow Coma Scale score on admission was 15 points, while the Hunts and Hess scale score was grade 1. Routine laboratory investigations were performed in the normal range. Electrocardiogram and chest radiography did not show any abnormalities.Computed tomography (CT) revealed a subarachnoid hemorrhage (SAH) and hematoma in the right frontal lobe Fig. A. CTA alIntraoperatively, the ruptured IA was located in the A2 segment of the right anterior cerebral artery (ACA), whereas the other 2 were located in the M1 and M2 segments of the right middle cerebral artery (MCA) , and 31% presented with combined hemorrhagic pattern. They further observed that in patients with SAH, 41% presented with focal deficits, 28% presented with IVH, and 3% of patients hesitated to have severe disability. Sturiale et al studied the relationship between nidus size and extension of the associated parenchymal hematoma and observed that nonparenchymal bleeding might worsen the prognosis of patients with hemorrhagic AVMs.Brown et al–8 Cagnazzo et al also observed in a meta-analysis that patients with concomitant AVMs and IAs were more likely to present with hemorrhage compared with the general AVM population (64% vs 50%). They indicated that, among patients with concomitant AVMs and IAs, the origin of the hemorrhage was the IA in 49% of patients and in 80% of patients, flow-related IAs were the most frequent source of aneurysmal hemorrhage. They further revealed that in patients with ruptured AVMs with associated IAs, the origin of the hemorrhage was the IA in 49.2% of patients, while in 45% of them, the AVM nidus was the source of the hemorrhage and the origin of bleeding was uncertain in 5.7% patients.Studies have shown that patients with concomitant occurrence of AVMs and IAs often have approximately 7% to 10% chances of rupture compared with approximately 2% to 4% chances of in patients with AVMs without related aneurysms.,14 Venous drainage often originates at the nidus level with the arterial vessels ending just before, such that the arteriovenous shunt would arise slightly proximal to the nidus, as observed in surgical findings and pathologic studies.,14 Furthermore, the function of the red veins is another key pathophysiological indicator.,14 AVMs draining veins often contain arterialized blood and sustained arterial pressure.,23 Their walls may be easily disrupted and mistaken for arteries.,23 Moreover, both the arterial and venous AVM segments secrete the S2 marker, suggesting a contractile phenotype of smooth muscle cells. Thus, venous segments of brain AVMs can easily be mistaken for arterial components.,24The pathophysiology of AVM is depicted with a nidus composed of a conglomeration of venous tangles and loops.,13 Second, their correlation may be spontaneous or coincidental.,14 Third, IA may occur because of hemodynamic stress associated with augmented flow to the AVM.,25 These theories do not contradict each other, and all 3 may be acceptable because distinctive types of concomitant occurrences of IAs and AVMs have been observed. It is worth noting that many classifications have been suggested for concomitant IA and AVM.,11,26 These include prenidal, intranidal, and postnidal IAs. The prenidal types, which are entirely arterial lesions, are often subdivided into flow-unrelated, flow-related, and flow-related adjacent types according to their location in relation to the AVM nidus, whereas the latter types are completely intranidal and postnidal venous lesions. Prenidal IAs are often associated with the rate of blood flow and are usually found in AVM vessels. The 3 IAs in our patients were of the prenidal type (flow-related remote type) based on their location in relation to the AVM nidus.There are 3 main theories regarding the causes of the concomitant occurrence of AVMs and IAs. Firstly, both lesions are congenital malformations. If hemorrhage was established during CT evaluation, CTA was performed to determine the cause of the hemorrhage. CTA can show both AVMs and IAs. CTA is also capable of detecting the site of bleeding in prenidal, intranidal, and postnidal IA. In our patient, CT revealed SAH and hematoma in the right frontal lobe, while CTA revealed a right frontal AVM with 3 IAs. AVMs with associated IAs. MRI can detect shunts and evaluate the perinidal brain parenchyma. In addition, MRA is capable of detecting dilatation of arterial feeders depending on the shunt volume and flow-induced IAs along the feeding arteries. We did not perform MRI or MRA because we planned to manage the patient in our hybrid room, where we could perform diagnostic DSA.The key symptom in our patient was the sudden onset of severe headache, dizziness, nausea, and vomiting. When hemorrhage is suspected, CT is often performed to establish intracranial bleeding. DSA is also capable of showing the number of distinct compartments within the AVM, any intranidal or perinidal IA, the nature of the venous drainage, and related varices and stenoses. The DSA is a key component of a hybrid operating room. Thus, we opted to perform diagnostic DSA during the treatment of the patient via the endovascular route in our hybrid operating room. Our diagnostic DSA confirmed the location of the AVM, 3 IAs, and feeders of the AVM. Surgery and endovascular therapy are the main treatment options for AVMs and IA. Studies have shown that treatment with an AVM alone results in a regression of IAs on proximal feeding vessels.,8,27DSA can be used to analyze AVM architecture, such as the nature and number of feeding arteries.,28 Coil embolization is used to essentially obliterate the IA, whereas Onyx or NBCA embolization is frequently used for occlusion of the artery from which the IA arises. In some cases, Onyx and NBCA have been used to precisely obliterate IA with conservation of flow within the parent artery.,28 Precipitation hydrophobic injectable liquid (PHIL) and SQUID are current liquid embolic agents that can be used to manage patients with AVMs with associated IAs.Coil embolization, Onyx or N-butyl cyanoacrylate (NBCA) embolization, and ethanol sclerotherapy are endovascular treatment modalities for AVM-related IA.,19,30 Miyasaka et al observed an overall regression rate of 14% for IAs with related AVMs after the AVMs were treated. Redekop et al also observed spontaneous regression of 50% of untreated IAs related to AVMs after gamma knife surgery for AVMs. They observed total resolution of flow related types and V-type IAs in 80% of patients when the AVMs were totally obliterated.Several studies have demonstrated that proximal flow-related IAs, such as pedicle IAs, may drastically reduce or even vanish when they are not treated at the time of AVM obliteration.–5,32 Nevertheless, there are no reports on the use of the hybrid operation concept in treating concomitant AVMs and multiple IAs. Identification of complications and augmented treatment goals are often achieved using intraoperative imaging during neurosurgery.,32,33 Several studies have demonstrated that intraoperative DSA and near-infrared indocyanine green video angiography are capable of evaluating vascular flow during cerebrovascular surgery and contribute to safety and avoidance of severe complications during cerebrovascular procedures.,33We utilized the hybrid operation concept to successfully treat both AVMs and IAs. Studies have shown that a combination of microsurgery, intraoperative DSA, and endovascular therapy in a hybrid operating room is an innovative, safe, and effective method for the treatment of AVMs, particularly high-grade AVMs.The hybrid operating room was crucial in the management of our patient because we were able to assess the vasculature of the lesions intraoperatively. Intraoperatively, DSA clearly demonstrated the arterial supply of both lesions, as well as the draining sinus of the AVM. We were able to occlude the 2 unruptured IAs and embolize the feeding arteries of the AVM, after which we performed a craniotomy to resect the AVM and clipped the ruptured IA in a single operation. The hybrid operation concept minimized intraoperative blood loss and complications associated with the management of both AVMs and IAs. Intraoperative DSA was performed immediately after surgical resection of the AVM to confirm total AVM resection.4The hybrid operating room is an innovative, safe, and effective method for the treatment of AVMs and associated IAs, particularly high-grade AVMs and IAs with hemorrhage or SAH. Coil embolization was used to obliterate the IA, whereas Onyx embolization was used to occlude the artery from which the IA arose subsequent to craniotomy and resection of the AVM. Patients with concomitant AVMs and IAs had the highest chance of hemorrhage compared with those with AVM or IAs alone.All authors contributed to data collection, drafting, and critical revision of the paper and agree to be accountable for all aspects of the work. Seidu A. Richard wrote the manuscript.Conceptualization: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Janwei Lv, Seidu A. Richard.Data curation: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Janwei Lv, Seidu A. Richard.Formal analysis: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Seidu A. Richard.Funding acquisition: Fei Xie.Investigation: Janwei Lv.Methodology: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Seidu A. Richard.Resources: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Janwei Lv, Seidu A. Richard.Supervision: Fei Xie.Writing – original draft: Seidu A. Richard.Writing – review & editing: Fei Xie, Lin Huang, Yongqiang Ye, Jianqiang Hao, Janwei Lv, Seidu A. Richard.


Large iatrogenic coronary artery perforations require rapid management; however, operators must be able to recognize guidewire perforation into cardiac veins in order to avoid causing further complications with standard salvage strategies. Large iatrogenic coronary artery perforations require rapid management; however, operators must be able to recognize guidewire perforation into cardiac veins in order to avoid causing further complications with standard salvage strategies. Repeat ECG , including nonculprit high grade obstructive lesions in the proximal right and mid‐circumflex coronary arteries, as well as a culprit complete occlusion of the mid‐LAD immediately distal to an aneurysmal segment of the vessel that also gave rise to a large diagonal branch Video .2Repeated attempts were made to primarily wire the LAD using a Runthrough workhorse wire ; however, this was unsuccessful as the wire was constantly deflected into the diagonal branch Video . MicrocaAttempts at wiring the lesion using a hydrophilic tapered wire  and a polymer jacketed wire (Pilot 50: Abbott Vascular) supported by a stiffer microcatheter  also failed. An emergent multidisciplinary team meeting was called between a cardiac surgeon, the interventional cardiologist, and the patient's inpatient cardiologist. All physicians agreed that due to the patient's age, frailty, and comorbidities he was not a surgical candidate. The patient continued to experience severe chest pain despite aggressive analgesic administration with clear ST‐elevations still present on ECG. Given the extensive calcific disease appreciated on his angiograms, it was hypothesized that treating the lesion as a chronic total occlusion (CTO) and proceeding with an antegrade wire escalation strategy might prove successful. Ultimately, the lesion appeared to be crossed using a controlled drilling technique with a Miracle Brothers 3 wire (Asahi Intecc USA) Video .The microcatheter was advanced into the distal vessel and intraluminal position was confirmed via a distal tip injection Video . Of noteAs the operators believed that the microcatheter had crossed into the distal LAD, the distal vessel was then safely wired using a workhorse wire to allow for equipment delivery. Due to challenging equipment delivery, a 1.5 × 12 mm compliant balloon was used to predilate the lesion followed by a 2.0 × 15 mm compliant balloon. A subsequent angiogram revealed extensive contrast extravasation from the vessel leading to the diagnosis of CAP Video .Salvage techniques for CAP were initiated according to the standard perforation care algorithm detailed in Figure Balloon tamponade was attempted utilizing the 1.5 mm balloon already in the vessel, followed by immediate upsizing to a 2.0 mm balloon that was inflated in the proximal vessel, with repeat angiograms showing no persistent contrast extravasation. Transthoracic echocardiography was performed, revealing no evidence of a pericardial effusion. Repeat injections performed during transient balloon deflations revealed continued extravasation of contrast. Obtaining an additional arterial access site for the purpose of utilizing dual‐guide catheter (“ping‐pong guides”) technique was discussed; however, this was deferred given the previous challenge crossing the lesion initially.At this time, the patient developed vomiting, hypotension, and ultimately ventricular fibrillation requiring multiple defibrillations and chest compressions. He was intubated emergently and cardiac anesthesia performed transesophageal echocardiography, which showed no evidence of pericardial effusion, but an akinetic anterior wall of the left ventricle. An intra‐aortic balloon pump (IABP) was simultaneously inserted through the right femoral artery, and the patient was started on norepinephrine with resultant stabilization of his hemodynamics. Selective LAD angiography performed through a guide catheter extension demonstrated phasic flow in the distal vessel as well as a channel connecting the mid‐vessel and CS, which was thought to represent an iatrogenic arteriovenous fistula (AVF) Video . The opeAdvancement of a covered stent across the mid‐vessel was not possible, so a 2.5 × 20 mm drug eluting stent (DES) was advanced and deployed across the perforation to permit tracking of a covered stent. Angiography following DES deployment revealed TIMI 3 flow in the distal vessel for the first time during the case, with continued robust flow into the CS through multiple channels. Additionally, an unusual “myocardial blush pattern” was observed as well as extensive flow into the coronary veins Video .A 2.8 × 16 mm Graftmaster covered stent (Abbott Vascular) was deployed across the visualized perforation; however, a residual channel connecting the vessel and the CS was visualized distal to the covered stent Video .A second 2.8 × 16 mm covered stent was placed across the remaining channel and postdilated, effectively closing the perforation with no further flow visualized into the CS. Final angiograms also revealed several small contained wire perforations, persistence of the unusual “myocardial blush pattern” and even more robust filling of the major cardiac veins Video .Post–procedure LV systolic function remained severely diminished, with an ejection fraction of 15%. He remained hemodynamically stable with an IABP in place on low dose norepinephrine and dobutamine. He went on to develop oliguric renal failure, and after multiple discussions with his wife surrounding goals of care, comfort measures were pursued and he died due to cardiogenic shock on post–procedure day four.Upon dedicated review of the patient's images by a team of multiple interventional cardiologists, it was determined that the operator's original hypothesis that the wire had perforated into the CS multiple times prior to reentering the LAD was likely incorrect. It appeared that the stiff wire had perforated through the aneurysmal segment of the mid‐LAD into the AIV. A large AVF was created once angioplasty was performed across the perforation and was then propagated by the DES and ultimately the covered stent. The channel connecting the vessel to the LAD was the normal outflow from the AIV, which when a covered stent was deployed across, resulted in vigorous flow from the AIV into the other major cardiac veins. The “unusual blush pattern” is occasionally noted in selective pressurized cardiac vein injections typically performed during electrophysiology procedures.3Coronary artery perforation represents a rare, but potentially fatal complication surrounding PCI4Cases of CAP leading to iatrogenic AVF are very rare, and if unrecognized carry a grim prognosis. Unfortunately, the literature surround management of PCI‐related iatrogenic AVF is limited, and the optimal management strategy for perforation into a vein is not well defined.None declared.ER: drafted and wrote the article. JF: edited and reviewed the article. JD: reviewed the article and provided key clinical insights. MY: revised the manuscript and helped prepare it for final submission.This case is anonymous and was published with permission from the patient's family.Video S1Click here for additional data file.Video S2Click here for additional data file.Video S3Click here for additional data file.Video S4Click here for additional data file.Video S5Click here for additional data file.Video S6Click here for additional data file.Video S7Click here for additional data file.Video S8Click here for additional data file.Video S9Click here for additional data file.Supplementary MaterialClick here for additional data file.


BackgroundProcedural simulation enhances early endoscopy training. Multiple commercial simulators are available; however, their application is limited by cost and poor user compliance. First-person “shooter” (FPS) video games are popular. In this study, we aimed to show that a novel in-house designed colonoscope controller used to play an FPS video game shares similar constructs with real-life endoscopy.MethodologyParticipants completed the first three levels on an FPS video game, Portal , first using a conventional controller and then the modified endoscope controller. A total of 12 expert endoscopists and 12 surgical residents with minimal endoscopy experience were evaluated based on completion time, button presses, and hand motion analyses.ResultsExperts outperformed novices for completion time  and hand movements  in using the novel colonoscope controller. There was no difference in button presses or total path length traveled. Furthermore, performance did not differ using conventional game controls.ConclusionsExperts outperformed novices using the endoscope but not the conventional controller with respect to the economy of movement and completion time. This result confirms that our endoscope-controlled video game shares similar paradigms with real-life endoscopy and serves as a first step toward creating a more enjoyable and cheaper alternative to commercially available endoscopy simulators. Surgical training is facing new challenges, including work hour restrictions -4, limitSome authors have hypothesized that first-person “shooter” (FPS) video games can help develop early endoscopy skills . The comWe hypothesize that a challenge facing early endoscopy trainees is familiarization with the control head. By integrating a conventional endoscope as a controller for a commercially available video game and instituting a training regimen utilizing an FPS platform, we hope to create a cheaper training tool that will improve early endoscopy performance and that trainees will find fun to play. Therefore, the overall goal of this initial proof of concept study was to collect validity evidence for the use of a novel endoscopy training tool by demonstrating that trained endoscopists outperform novices using our controller.Study design and theoretical frameworkMessick’s validity framework was used as the underlying theoretical framework to guide this research. This framework has become the gold standard when evaluating validity evidence for performance assessments and is supported by multiple national and international education and research organizations . In brieParticipants and sampleThe novice group consisted of junior surgical residents with minimal or no personal experience with endoscopy. The expert group consisted of fully trained staff surgeons accredited by the Royal College of Physicians and Surgeons of Canada who are proficient in endoscopy and perform endoscopy in their usual practice. Participants were recruited by convenience sampling.Previous skills training research suggests effect sizes ranging from 1.0 to 1.2 standard deviations between novices and experts ,25,26. AController and video gameA colonoscope without a camera, light source, or power was specially modified for this study and used as the controller to play the video game Figure . A woodeThe video game used in the study was Portal , a primarily problem-solving game that employs FPS constructs. Participants were asked to play through the first three levels of the game as quickly as possible, first using the mouse and keyboard, and then using the novel colonoscope controller. The tasks that participants had to perform in the game include advancing forward, backward, and sideways in simulated three-dimensional environments; shooting large holes in walls ; lifting and placing blocks onto compressible buttons; and opening and progressing through doorways. This video game involves targeting walls and objects but does not involve any targeting of simulated people or characters. The custom gameplay settings in Portal’s software used during the study period are available upon request.Study procedureAfter informed consent was obtained, all participants were asked to perform an initial pre-study questionnaire exploring demographic information, including all past video game experience, and FPS video game experience, rated on a seven-point Likert scale to account for potential confounding related to video game familiarity. Participants were then shown a video Video  orientinThe primary outcomes compared were time to task completion, total distance traveled, and the number of discrete movements, as assessed by HMA. These are previously validated metrics for expertise in procedural tasks, including endoscopy ,27-30. THand motion analysisElectromagnetic sensors (8 mm)  were applied to the dorsum of participants’ hands at the mid-shaft point of the third metacarpal. Data on each sensor’s position and orientation  were collected using commercially available software . Data were interpreted using Motion Analysis and Recording Software version 3.0 (MARS3) developed by our institution . Clinically insignificant background movements from hand tremors were eliminated via a Gaussian filter set to a frequency cut-off of 1.666 Hz. Registration of a discreet movement is triggered by a change in velocity greater than 15 mm/s. These variables are based on previously validated thresholds ,31. As aStatistical analysisStatistical comparisons were performed using SPSS Statistics software version 27 . The mean time, the number of button presses, hand movements, and hand path length data were compared between each group utilizing the Mann-Whitney U test as data were not normally distributed. Normality was tested using the Shapiro-Wilk test and visually with a Q-Q plot and histogram. Homogeneity of variance was determined by Levene’s test. Statistical significance was set at α = 0.05. To assess the effects of self-reported video game and FPS experience, these data were compared to HMA outcomes via the Spearman correlation coefficient. Past colonoscopy experience was compared to HMA outcomes via a Pearson correlation.Participant characteristics including past endoscopy, endoscopy simulator, video game, and FPS game experience are described in Table Using the modified colonoscope controller, experts completed the three video game levels with fewer total movements  and in less time  compared to novices. The number of left-hand but not right-hand movements was also smaller for experts versus novices. Experts and novices did not differ for the number of button presses or total path length traveled (Table There were no differences between novices and experts using the conventional mouse and keyboard controls Table .Self-reported total lifetime video game experience and FPS game experience were both significantly correlated with time to completion using standard mouse and keyboard (rs = -0.733, p < 0.0001; rs = -0.811, p < 0.0001, respectively; Figure Simulation will continue to play an important role in resident training, given work hour restrictions and patient safety concerns. Existing simulators have multiple limitations, including lack of portability, high cost, and poor compliance . This noThis study was designed to provide validity evidence by demonstrating that performance on the device can differentiate between novices and experts using multiple measures. The endoscope handle-based controller can differentiate between novices and experts in time to study completion and economy of motion. Experts made fewer movements compared to novices and completed the study objectives in less time. In other studies, economy of motion has been well-validated as an assessment tool for procedural expertise, including colonoscopy ,27-30. FThere were no differences in the number of button presses or total path length traveled by participants’ hands between the novice and expert groups. Button presses are not a previously validated metric of expertise. We hypothesized that novices may press more buttons unnecessarily, possibly out of desperation or frustration; however, this behavior was not observed. While the difference in path length between groups was not significant, experts did trend toward a smaller path length Table . PerhapsOne purported limitation of using video games to assess surgical skills is the potential for video game expertise to bias results . As suchDespite the importance of our findings, there are a few notable limitations. This study provides initial validity evidence for this controller using a single FPS video game. Experts outperform novices using this combination only. We have not assessed whether these skills are generalizable to other games while using this controller, nor have we assessed whether this controller can be used to train basic endoscopy skills. In its current form, this device is compatible with many computer games that require the use of a few buttons, a mouse, and forward/backward controls. Trainees can tailor this adaptable system to their favorite games. However, at present, it is unclear if using a different game would yield training benefits, especially using a different game genre. Based on constructs used in endoscopy, we hypothesize that a flight simulator may be another potential genre to trial.Other sources of validity evidence recommended for assessing surgical simulation tools have not yet been measured for this novel controller. For this study, licensure and the number of past endoscopies performed were used as a surrogate marker for endoscopy expertise. A scoring system to assess these movements was not used, as existing metrics such as the Global Assessment of Gastrointestinal Endoscopic Skills for Colonoscopy  or FES  do not aAnother important limitation is cost. The current prototype used a colonoscope donated by the manufacturer. A new colonoscope is costly. Those who wish to build their own version of this model could save money by purchasing used or refurbished scopes, which are available online starting at $150. As we did not use any colonoscope parts aside from the dials and the tube, a nonfunctioning colonoscope without fiberoptics and lights could be a less expensive viable option. Additional costs include the Leap Motion controller, which can be purchased new for $100. The wood, Styrofoam, tape, and copper pipe used to make the stand were inexpensive. The GameWave computer software is free, and most trainees would have access to a laptop.In its current form, this model is inexpensive enough that trainees could build their own and is comparable in price to many commercial video gaming systems available. However, the real strength of this apparatus is its potential as an educational tool through which endoscopy trainees can learn new skills while playing. It could be used outside work hours during leisure time and offers an opportunity to do so more conveniently at home rather than in an institutional simulation lab.Experts outperformed novices using a modified colonoscope to control an FPS video game with respect to economy of movement and completion time. This result demonstrates that this endoscope-controlled video game shares similar constructs with real-life endoscopy and serves as a first step toward creating an enjoyable alternative to commercially available endoscopy simulators. Future studies should aim to establish repeatability of measurements and correlate training improvements on this model with corresponding improvements in objective endoscopy performance.


To report a case of gonioscopy-assisted transluminal trabeculotomy (GATT) in a patient with primary congenital glaucoma.A three-year-old boy who presented with buphthalmos and elevated intraocular pressure. Despite the presence of iris and iris processes extending to Schwalbe's line, GATT was performed successfully.GATT may be successful with primary congenital glaucoma even when angle structures are not initially visible. His visual acuity was 0.2 in the right eye (OD) and 0.04 in the left eye (OS), respectively. He had no previous ophthalmic history and no family history of ocular disorders or systematic abnormalities.Under general anesthesia, corneas were enlarged (14 mm), but clear  and therSee surgical video 1). In brief, the microcatheter was inserted into the Schlemm's canal and passed circumferentially around the entire canal. The two ends of the microcatheter were fixed and retrieved within the chamber using microsurgical forceps. The blinking head of the catheter allows for the visualization of the actual dynamic positioning and avoid misleading around the angle.He was diagnosed with PCG OU and scheduled for GATT. At the time of surgery, the anterior chambers were deepened with viscoelastic. With gonioscopy, the iris was observed to cover the entire angle up to Schwalbe's line A, and anhttps://doi.org/10.1016/j.ajoc.2022.101366.Supplementary video related to this article can be found at The following is the supplementary data related to this article:See surgical video 2).On the first post-operative day, IOP was 10 mm Hg OD. After one week, his IOP was 6-mm Hg. The same surgery was performed one week later in OS with similar results. GATT was successfully performed with twice 270-degree goniotomy .GATT was first proved to be successful in adult glaucomahttps://doi.org/10.1016/j.ajoc.2022.101366.Supplementary video related to this article can be found at The following is the supplementary data related to this article:The complications of GATT should be considered. The iridodialysis, post-operative IOP spike, and hyphema are common post-operative complications.No funding or grant support.All authors attest that they meet the current ICMJE criteria for Authorship.Written consent to publish this case has been obtained. This report does not contain any personal identifying information.The following authors have no financial disclosures: YHS, XLZ and RNW.


Microsurgery using conventional optical microscopes or surgical loupes features a limited field of view and imposes a serious strain on surgeons especially during long surgeries. Here we advocate the micro- and macro-borderless surgery (MMBS) using a novel high-resolution (4K) three-dimensional (3D) video system. This study aimed to confirm the applicability of this concept in several surgical procedures.We evaluated the possible use and efficacy of MMBS in the following experiments in porcine subjects. Experiment 1 (non-inferiority test) consisted of dissection and anastomosis of carotid artery, portal vein, proper hepatic artery, and pancreatoduodenectomy with surgical loupe versus MMBS. Experiment 2 (feasibility test) consisted of intra-abdominal and intra-thoracic smaller arteries anastomosed by MMBS as a pre-clinical setting. Experiment 3  consisted of orthotopic liver transplantation of the graft from a donor after circulatory death maintained by machine perfusion. Circulation of the cardiac sheet with a vascular bed in experiment 2 and liver graft during preservation in experiment 3 was evaluated with indocyanine green fluorescence imaging equipped with this system.Every procedure was completed by MMBS. The operator and assistants could share the same field of view in heads-up status. The focal depth was deep enough not to be disturbed by pulsing blood vessels or respiratory movement. The tissue circulation could be evaluated using fluorescence imaging of this system.MMBS using the novel system is applicable to various surgeries and valuable for both fine surgical procedures and high-level surgical education. In 1989, laparoscopic cholecystectomy was introduced as an alternative to the open procedure. However, its significance was actually more than just technicality, it was a cultural revolution towards camera-assisted surgeries, whose fruits were thought to keep being harvested for decades  ophthalmWith the introduction of the three-dimensional (3D) image into surgery, 3D tasks were believed to be more accurately and quickly performed than the ordinary two-dimensional ones . This apHowever, in some situations during microsurgery, especially in the abdomen and small arterial reconstruction, some obstacle such as: (A) Narrow field of view, (B) Deep operation field, (C) Respiratory movement that requires a significant depth of field (DOF) of the microscope, and (D) Setup of the microscope during the abdominal surgery takes approximately 15–30 minutes, which may consume more operative time. To overcome these issues, we developed the novel 4K-3D video system  with a hWhile the surgeon stands on one side of the operating table and the monitor is placed on the other side facing the operating table, the operator and the assistants perform the operation by watching the 3D monitor using an easy heads-up posture . It is pZoomed-in and -out images can be displayed seamlessly on the monitors. Total magnification (TM) consists of objective magnification (OM) and monitor magnification (IM). TM is calculated by the following equation: TM = OM × IM, where IM is the diagonal length of the monitor/diagonal length of the imaging element. By selecting the monitor size, the TM could be up to 110 times .This system has the ability to change the magnification from the lowest to highest in 1.8 seconds.This video system make it possible to achieve both high resolution  and a deSince the monitor is placed opposite the surgeon on the operating table, the objective lens is placed at a higher position above 100 cm from operating table, enabling both the operator and the assistants to visualize the operative field directly without disturbance by the objective lens .The camera has two imaging elements of visible and invisible light, which can both be projected onto the monitor and used in conjunction with fluorescence imaging, using indocyanine green (ICG), to confirm the blood flow .This 4-Metal Oxide Semiconductor (MOS) microscope and camera system is the world’s first to enable simultaneous shooting of visible and near-infrared (NIR) light. For high sensitivity, three visible lights  and ICG fluorescence wavelength light are separated by four prisms and captured by four independent sensors. Each light reaching the sensor is individually amplified by a parallel signal processing circuit, so a clear visible light image and a low-noise NIR image can be superimposed . A high-All animal experiments were approved by the animal research committee: Experiment 1 by the Kobe Medical Devise Developing Center (IVT17-24), Experiment 2 by Fukushima Medical Devise Developing Support Center (20191204–1), and Experiment 3 by the Kobe Medical Devise Developing Center (IVT19-01).All animal experiments complied with the ARRIVE guidelines and were carried out in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals . These experiments were conducted according to non-Good Laboratory Practices and a reliability criterion. Two female porcine subjects in Experiment 1 and one female porcine subject in Experiment 2 and 3 weighing 25 kg were used. All animals were sacrificed after the completion of all procedures by the administration of KCL under high-concentration (5%) isoflurane inhalation.We evaluated the possible use and efficacy of MMBS in the following 3 experiments. All of the operative procedures except for the surgical loupe group in Experiment 1 were performed by seeing the monitor set in front of the operative table using the high-resolution 4K-3D video system (MMBS concept).Portal vein, hepatic arterial reconstruction, and pancreaticoduodenectomy were evaluated in porcine subjects using MMBS or surgical loupe. Two porcine subjects were used as liver transplant and pancreaticoduodenectomy models and operated on by expert hepatobiliary pancreas and transplant surgeons. The operations were performed using only a surgical loupe  with a magnification of 2.5–4.5× in one subject and using MMBS in another porcine subject.For further evaluation of the applicability for smaller arterial anastomosis in the abdominal and cardiovascular surgery, we performed a left hepatic arterial anastomosis and anastomosis between the internal thoracic artery and a cardiac sheet with vascular bed derived from porcine small intestine . The cirIn order to address the challenges of a new surgery, we performed ischemia-free liver transplantation  of the lAfter 12 h of fasting, anesthesia was induced by the intramuscular administration of ketamine hydrochloride (5 mg/kg) and atropine sulphate (1 mg/body) followed by endotracheal intubation and maintenance with oxygen, nitrous oxide, and isoflurane by positive pressure mechanical ventilation.These following procedures were performed using only a surgical loupe in 1 porcine and was performed using only a 4K-3D video system in another porcine: (1) hepatic arterial anastomosis (3.5 mm in diameter) with interrupted 9–0 polypropylene sutures ; (2) portal vein (PV) anastomosis (10 mm in diameter) with continuous 6–0 ASFLEX; (3) dissection of the pancreas; (4) pancreaticojejunostomy; anastomosis between main pancreatic duct (1.5 mm in diameter) and jejunum with an internal stent using a 24G catheter by interrupted 6–0 ASFLEX with modified Blumgart anastomosis [The surgical procedures including dissection of the vessels and anastomosis were compared in terms of feasibility and the posture of the surgeons and assistants.One porcine subject was subjected to the following: (1) exposure and anastomosis of left hepatic artery (1.5 mm in diameter) with interrupted 9–0 ASFLEX; (2) exposure of the internal thoracic artery after a sternal midline incision; (3) anastomosis between the internal thoracic artery and veins (3 mm in diameter) and the cardiac sheet derived from the porcine intestine using the tissue engineering technique with 9–0 ASFLEX; (4) confirmation of the blood flow of the cardiac sheets using ICG fluorescence imaging after injection of 2.5 mg/body ICG  intravenously.Ischemia-free liver transplantation was demonstrated with an orthotopic method of another study . BrieflyIt takes approximately 10 minutes to set up the devise . The devise does not require any special start-up running operation. In the both surgical loupe and MMBS using 4K-3D video system groups, dissection and anastomosis in the PV, and common hepatic artery were completed without complications as well as pancreaticoduodenectomy (MMBS procedures shown in The left hepatic artery with a 1.5-mm diameter in a porcine model could be completed by MMBS using the 4K-3D video system . The intMMBS was conducted using the following procedures: (1) liver-graft procurement, (2) catheter insertion at the PV and hepatic artery of the procured liver graft, (3) anastomosis of the vein graft to the recipient’s PV and IHIVC, and (4) SHIVC anastomosis and PV anastomosis between the graft liver and recipient . Tissue We developed a novel high-resolution 3D video system equipped with fluorescence imaging that can rapidly magnify and confirm the blood flow in the vessels as well as organ perfusion using the new MMBS concept with the heads-up status of the surgeons, which could be applied in various surgical fields. Although the heads-up posture in microsurgery has been reported in ophthalmology, neurosurgery and head and neck surgery –4, the sWhile conventional video microscope systems have a working distance of 200 to 600mm, the new system has a working distance of 200 to 1000mm, making it possible to flexibly respond to a variety of procedures. In addition, the new system is equipped with a newly designed optical system with an 8x zoom that enables the resolution of a 4K camera, allowing observation from low to high magnification. The on-board 4K camera sensor is a new 4-chip type that can simultaneously perform white light observation and near-infrared fluorescence observation, making it possible to clearly observe ICG blood flow in real time. In brief, our system differs greatly from previous 4K-3D video systems in term of its large working space due to the high-performance objective camera with 4- MOS. Belykh E. et al.  reportedThis device is equipped with excitation of the ICG fluorescence of the blood flow and liver tumors such as hepatocellular carcinoma or metastatic liver tumors superimposed on a 3D monitor in real time, which would be applicable to navigation surgery , such asEpstein et al.  reportedMMBS should facilitate microsurgical vascular anastomosis. In order to optimize the new system, it is necessary for the surgeon and assistants to be well trained in order to become familiar with the device. Furthermore, the position of the monitors needs to be carefully considered so that both the surgeon and the assistant can see the monitors well depending on the area to be operated on. Our next goal is to create a database of surgical techniques that can be used to train future surgeons by taking advantage of this new system. In addition, we can use this system to capture the digital data of the projected surgical field. Since the digital data can be streamed live, it may be possible to connect with an authoritative surgeon in a distant location as an advisor for a difficult operation.Recently, organ fabrication in the field of regenerative medicine has advanced rapidly. However, its clinical application requires performing fine surgical techniques using a microscope or surgical loupes, which is challenging to surgeons, particularly those involved in basic research. To overcome these hurdles, the newly developed 4K-3D video microscope allows microsurgery in an easy heads-up posture by the operator and can be applied in highly complex surgical procedures of vascular reconstruction and regenerative medicine.This newly developed 4K-3D video system may also improve the safety of the surgery itself, as everyone observing have the same field, and they can simultaneously check the exact tumor location and assure the blood flow. However, there are some limitations of this MMBS concept. It would be difficult to perform procedures with MMBS in areas where light cannot penetrate from above, such as the posterior and lateral walls, as with conventional microscopes. In the next step, we will evaluate this concept using our developing 4K-3D video system in a clinical study.In conclusion, this novel MMBS concept using a 4K-3D video system with a heads-up posture is valuable for micro- and macro-borderless fine surgical procedures in various operations as it aids less straining surgeon posture and can facilitate high-level surgical education.S1 Fig(A) The 9–0 and 12–0 polypropylene threads and needles are clearly seen. (B) Depth of field was 4–5 mm when the working distance was 100 cm.(TIFF)Click here for additional data file.S2 Fig(TIFF)Click here for additional data file.S3 FigIndocyanine green (ICG) fluorescence imaging of the graft during the preservation period. (A) Monitor image display without ICG and (B) in near-infrared ICG mode; the green part represents ICG in circulation.(TIFF)Click here for additional data file.S1 Video(MP4)Click here for additional data file.S2 Video(MP4)Click here for additional data file.S3 Video(MP4)Click here for additional data file.S4 Video(MP4)Click here for additional data file.S5 Video(MP4)Click here for additional data file.S6 Video(MP4)Click here for additional data file.


As 25% of body Mg2+ is located in the skeletal muscle, Mg2+ transport and homeostasis systems (MgTHs) in the muscle are critical for whole-body Mg2+ homeostasis. In the present study, we assessed whether Mg2+ deficiency alters muscle fiber characteristics and major pathways regulating muscle physiology. C57BL/6J mice received either a control, mildly, or severely Mg2+-deficient diet  for 14 days. Mg2+ deficiency slightly decreased body weight gain and muscle Mg2+ concentrations but was not associated with detectable variations in gastrocnemius muscle weight, fiber morphometry, and capillarization. Nonetheless, muscles exhibited decreased expression of several MgTHs . Moreover, TaqMan low-density array (TLDA) analyses further revealed that, before the emergence of major muscle dysfunctions, even a mild Mg2+ deficiency was sufficient to alter the expression of genes critical for muscle physiology, including energy metabolism, muscle regeneration, proteostasis, mitochondrial dynamics, and excitation–contraction coupling.Chronic Mg Mg2+ is a natural Ca2+ antagonist, the activator of more than 200 enzymes, and the direct cofactor of over 600 enzymes [2+ is buffered by many biological molecules, including proteins, RNAs, DNA, and ATP. ATP is mainly bound to Mg2+, and MgATP2- is the active species in enzyme binding and energy production. Therefore, the intracellular concentration of Mg2+ must be tightly regulated. This is achieved through the activity of Mg2+ permeable channels and transporters. The last few years have seen rapid progress in the identification and characterization of Mg2+ transport and homeostasis systems (MgTHs), including transient receptor potential cation channel subfamily M member 6 (TRPM6) and 7 (TRPM7), magnesium transporter 1 (MagT1), magnesium transporter MRS2, solute carrier family 41 member 1 (Slc41a1) and 3 (Slc41a3), cyclin, CBS domain divalent metal cation transport mediator 1 (CNNM1) and 4 (CNNM4) [2+ homeostasis is regulated by the combined action of several ubiquitous Mg2+ transporters. Mg enzymes . In addi (CNNM4) ,9. Altho2+ controls contraction by acting as a Ca2+ antagonist on Ca2+-permeable channels and Ca2+-binding proteins. Accordingly, Mg2+ deficiency decreases muscle strength [2+ status, is characterized by the gradual decline of muscle mass and performance. About 25% of body Mg2+ is located in the skeletal muscle, which indicates that the expression of MgTHs is relevant to whole-body Mg2+ homeostasis. Gene and/or protein expression of ubiquitous MgTHs have been demonstrated in the skeletal muscle (http://www.proteinatlas.org/ accessed on 10 April 2021), but their specific functions in this tissue have not been elucidated. Moreover, to our knowledge, few studies on the regulation of MgTHs in skeletal muscle under pathophysiological conditions, including Mg2+ status, have been published [Besides its role in energy production, in the skeletal muscle Mgstrength . Moreoveublished .2+-containing diet. The principal aim of this study was to individuate whether and how a short-term Mg2+-deficient diet modulates muscle fiber characteristics and cellular pathways critical for muscle physiology.We were interested in unveiling the early events occurring in the skeletal muscle in response to a low Mg2+ wt/wt). The mice were then randomly divided into three groups, and over the following two weeks, each group (n = 12) was fed one of the three following diets: control diet (0.1% Mg2+ wt/wt), mildly Mg2+-deficient diet (0.01% Mg2+ wt/wt), or severely Mg2+-deficient diet (0.003% Mg2+ wt/wt). The Ca2+ content of the diets was 0.4% (wt/wt). All diets were prepared in our laboratory. Distilled water and food were available ad libitum. Quantitative magnetic resonance of live mice was carried out to estimate body fat and lean mass using an EcoMRI-100 analyzer . At the end of the experiment, the animals were sacrificed, blood was collected from the heart in heparin-containing tubes, and gastrocnemius muscles were excised. Plasma was obtained by centrifugation  and frozen for later analysis. Muscles were weighed and (i) maintained in RNAlater  overnight at 4 °C before extracting RNA, (ii) frozen in isopentane cooled on liquid N2 and stored at −80 °C for histology, or (iii) snap-frozen in liquid N2 for muscle Mg2+ measurements.The present study (APAFIS#14025-201803121538803) was approved by the Ethics Committee C2EA-02 and was conducted in accordance with the National Research Council Guide for the Care and Use of Laboratory Animals. All animals were maintained in a temperature-controlled room (22 ± 1 °C) with a 12:12 h light:dark cycle and handled according to the recommendations of the Institutional Ethics Committee. Two-month-old male C57BL/6J mice were housed for one week in a standard environment with a control diet .Plasma magnesium was quantified using a Magnesium Calgamite kit according to the manufacturer’s instructions . Erythrocytes were washed 3 times with a saline solution, hemolyzed in water, and centrifuged. Muscle samples were mineralized in 65% HNO2/4π CSA) was calculated, with a value of 1.0 indicating a circle and >1.0 an increasingly elongated ellipse. A mean of 229 ± 13 capillaries was analyzed per subject. Capillary density (CD) was expressed as the number of capillaries counted per square mm. Capillary-to-fiber ratio (C/F) was calculated as the ratio between the number of capillaries and the number of fibers present in the same area [Serial cross sections (10 µm thick) were obtained using a cryostat  at −25 °C. Myofiber morphometry and capillarization were assessed on cross sections after labeling with anti-laminin-α1  and anti-CD31 , respectively, and capturing images by a BX-51 microscope  according to ,13. On aActb) transcript quantity.Independent RNA isolations were carried out for each gastrocnemius muscle sample. Total RNAs were extracted using the RNeasy Fibrous Tissue Mini Kit (Qiagen) following the manufacturer’s conditions. RNA concentrations were measured using a NanoDrop ND-1000 , and RNA quality was verified by 1% agarose gel electrophoresis. One μg total RNA was used as a template for single-strand cDNA synthesis using High-Capacity cDNA RT Kit  in a total volume of 20 µL containing 1 X RT buffer, 4 mM dNTP mix, 1 X random primers, 50 U reverse transcriptase and 20 U RNase inhibitor. The primer sequence is reported in Actb), β-glucuronidase (Gusb), and hypoxanthine phosphoribosyltransferase (Hprt) were used as controls. The genes analyzed are reported in A total of 500 ng (10 µL) cDNA of each sample was combined with 95 µL of nuclease-free water and 105 µL 2X TaqMan™ Fast Advanced Master Mix (Applied Biosystems) for the quantitative real-time PCR (qPCR) measurements. This mixture was divided equally over two sample-loading ports of the TLDA. The arrays were centrifuged once  to equally distribute the sample over the wells. Subsequently, the card was sealed to prevent exchange between wells. qPCR amplification was performed using an Applied Biosystems 7900HT system with the following thermal cycler conditions: 2 min at 50 °C and 10 min at 94.5 °C, followed by 40 cycles of 30 s at 97 °C and 30 s at 59.7 °C. Raw data were analyzed using Sequence Detection System (SDS) Software v2.4 (Applied Biosystems). The expression of β-actin (® TurboTM Transfer Pack (Bio-Rad). After blocking with bovine serum albumin (BSA), Western blot analysis was performed using primary antibodies against Myog, Opa1 , Gapdh, and Mfn2 . The filters were washed and incubated with secondary antibodies conjugated to horseradish peroxidase  were used. The immunoreactive proteins were detected with ClarityTM Western ECL substrate (Bio-Rad) and images were captured with a ChemiDoc MP Imaging System (Bio-Rad). The nitrocellulose sheets were used as control loading. Densitometry of the bands was performed with the software ImageLab (Bio-Rad). The Western blots shown are representative and the densitometric analysis was performed on three independent experiments.Gastrocnemius muscles were mechanically shredded in a Potter homogenizer with lysis buffer  containing protease inhibitors. Total proteins were quantified using the Bradford reagent . Equal amounts of proteins were separated by SDS–PAGE on 4–20% Mini-PROTEAN TGX Stain-free Gels  and transferred to nitrocellulose membranes by using Trans-Blott test or one-way ANOVA, followed by a Tukey’s post hoc test, as appropriate. Mann–Whitney U tests were performed when data in at least one group were not normally distributed. Correction for multiple testing was performed with R according to [P < 0.05.Data are presented as means ±SE. To determine whether or not data sets were normally distributed, the Shapiro–Wilk and Kolmogorov–Smirnov normality tests were performed. When data were normally distributed, statistical comparisons between groups were performed applying either Student’s rding to , and TLD2+ transport and homeostasis systems (MgTHs) in response to Mg2+ status, we used a model of C57BL/6J mice receiving a mildly or severely Mg2+-deficient diet and compared it to mice under an Mg2+-sufficient diet [2+-deficient diet exhibited a 26% and 75% reduction in plasma Mg2+ concentration, respectively , or capillary-to-fiber ratio (C/F)  b–d.2+ concentrations might nonetheless modulate specific mechanisms to maintain cellular Mg2+ homeostasis. We assessed whether Mg2+ deficiency could be associated with differential expression of MgTHs. qRT-PCR analyses performed on gastrocnemius muscle revealed significant declines in MagT1, CNNM2, CNNM4, and TRPM6 mRNAs in mice under Mg2+-deficient diets, compared to Mg2+-sufficient diets , CNNM2 , CNNM3 , CNNM4 , MRS2 , Slc41a1   b.2+ is the activator or cofactor of a number of enzymes, modest declines in intramuscular Mg2+ concentrations might modulate biological processes that are critical for muscle physiology. Initially, to assess muscle stress, we evaluated the expression of Trim72, Chac1, and Ddit3. Trim72 codes for a protein specifically located in the sarcolemma and involved in membrane repair [Chac1 encodes a protein acting downstream of ATF4 implicated in muscle atrophy [Ddit3 encodes a member of the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors and inhibits myogenesis [2+-deficient diets did not modulate Trim72  analyses revealed that mild Mg2+ deficiency was sufficient to rapidly alter the expression of genes important for lipid and carbohydrate metabolism -1, respectively, Gapdh, Cs (citrate synthase), Plin2, a marker of intramyocellular lipid droplets, and the transcription factors Creb1, Srebf1, and Srebf2. Mild Mg2+ deficiency also rapidly altered the expression of genes involved in muscle regeneration (Myog (myogenin), Mef2c (myocyte enhancer factor 2C), Mstn (myostatin), and its receptors (Acvr2a and Acvr2b). To reduce the potential interferences due to the activation of the stress response and to mimic chronic latent deficiency conditions, further investigations were focused on mild Mgtabolism a. These neration b, i.e., 2+-deficient diet. As shown in We tested the total amounts of some proteins by Western blot on lysates from gastrocnemius muscles of 12 animals under control or mildly Mg2+ deficiency was associated with a decreased expression of Fbxo32 (MAFbx), Zeb1, Fbxo31, Atf4, and Eif4ebp1, while the mRNA levels of other major regulators, e.g., Trim63 (MuRF1), Foxo3, Mdm2, Fbxo30 (Musa1), Fbxo21 (Smart), Gadd45a, and Cdkn1a (p21) did not significantly change , there was also evidence for altered expression of many genes involved in protein catabolism. This encompassed the downregulation of (i) E2-activating genes  of the ubiquitin–proteasome system , elongation , substrate/cargo recruitment  and lysosomal proteolysis  in autophagy   gutophagy c. Howevealpains) e.2+ deficiency is sufficient to downregulate genes regulating mitophagy  , mitochondrial fission , and fusion   d, in add, Rhot1) d. By Wes, Rhot1) c. Opa1, , Rhot1) d.2+ may also modulate Ca2+-permeable channels and Ca2+-binding proteins. Ca2+ handling by the sarcoplasmic reticulum is a key feature in muscle contraction. Action potentials elicit contraction by the release of Ca2+ from the sarcoplasmic reticulum through the ryanodine receptors (Ryr1) that are regulated by calsequestrin-1 (Casq1). For muscle relaxation, Ca2+ is transported back to the sarcoplasmic reticulum by sarco/endoplasmic reticulum Ca2+-ATPases (Serca), regulated by sarcalumenins (Srl) [2+ deficiency did not affect the expression of genes involved in contraction , while it downregulated the expression of those implicated in relaxation, Atp2a1 (Serca), and Srl (Mgns (Srl) ,26. It i and Srl e.2+ intake and loss of skeletal mass and function were reported in large population cohorts [Appropriate nutrition is indispensable for normal muscle metabolism and function . In huma cohorts ,28,29.2+ in muscle health, we developed an experimental model in which mice were fed a moderately or severely Mg2+-deficient diet. Both these dietetic regimens significantly reduced serum Mg2+ levels, a useful biomarker of Mg2+ status [2+ concentration, differently from a previous report demonstrating the concomitant reduction of serum and erythrocyte Mg2 in animals fed the severely deficient diet [2+ transporters were significantly downregulated in the muscle. This finding explains the reduced amounts of intracellular Mg2+ in the muscle and might also represent an initial, adaptive response aimed at maintaining circulating Mg2+ as close to physiological levels as possible. In this perspective, it is noteworthy that 12–13 week-old Trpm6-deficient adult mice are hypomagnesemic and sarcopenic, events reversible upon supplementation with Mg2+ [CNNM2+/− mice were hypomagnesemic, but no data are available on the skeletal muscle yet [2+ deficiency was associated with a significant decline in body weight gain. Interestingly, regression analysis revealed a positive correlation between body weight gain and the downregulation of MagT1, CNNM2, CNNM3, CNNM4, MRS2, Slc41a1 in the muscle. Indeed, redundancy among members of Mg2+ transporters likely enables functional compensation to maintain sufficient Mg2+ homeostasis resulting in normal body weight.To get insight into the role of Mg+ status . Unexpecent diet . We haveith Mg2+ . Additioscle yet . In our 2+ deficient regimen. This finding might be due to the downregulation of the genes coding for myostatin and its receptors, which activate the ubiquitin–proteasome and autophagy pathways, thus resulting in muscle wasting [2+ diet.We found no structural signs of muscle atrophy after 14 days in Mg wasting . Accordi2+ supplementation was sufficient to revert it [2+-deficient mice indicates that less glucose might be available for energy production, further impaired by the downregulation of Citrate synthase, involved in the first reaction of the Krebs cycle. Reduced amounts of Plin2, Srebf1, and Srebf2 transcripts might be predictive of altered lipid metabolism. It is noteworthy that Srebf1 and Srebf2 are downregulated in the skeletal muscle of diabetic individuals [Plin2 ameliorates insulin sensitivity in skeletal muscle [Slc6a8, coding for creatine transporter (CT)-1, is reduced in moderately Mg2+-deficient mice. In the skeletal muscle, the creatine system is fundamental for optimal energy utilization, especially at the beginning of exercise and during intense physical activity, because it serves as a first-line energy buffer that maintains ATP levels constant. CT1 is the major route for creatine entry in skeletal muscle cells and has a central role in ensuring high intracellular creatine content [By TLDA analysis, we found significant differences in the expression of genes coding for proteins involved in energy metabolisms. Glucose transport into cells is the first step in glucose metabolism. We here describe the downregulation of the gene encoding the glucose transporter Glut4. Interestingly, in the gastrocnemius of type 2 diabetic rats, Glut4 was reduced, and Mgevert it . The lowividuals  and thatl muscle . Additio content . Consist content .2+-deficient mice. Moreover, we found a marked reduction of the total amounts of Mfn2, a GTPase located on the outer mitochondrial membrane which is critical for mitochondrial fusion [2+-deficient mice. This result is in agreement with data from cultured cells. Indeed, both TRPM7 or MagT1 silencing and Mg2+ deficiency activate autophagy in human mesenchymal stem cells induced osteogenic differentiation [2+ inhibit autophagy in chondrocyte ATDC5 cells [TLDA also disclosed the reduced expression of genes involved in mitophagy, fusion, and fission, thus indicating alterations of mitochondrial dynamics that might be accompanied by impaired energy production in Mgl fusion . It is nl fusion . TLDA alntiation . ConsistC5 cells .Our study presents some limitations. First of all, the experiments were performed using young growing animals. It will be relevant to extend our studies using animals of different ages and to evaluate metabolic parameters related to glucose metabolism and lipid metabolism to obtain a complete overview of the fundamental function exerted by skeletal muscle. We also highlight that our study was performed on male mice. To identify potential gender-related differences, the same experiments should be performed on females. Another limitation is that only some proteins were evaluated. Further experiments are required to confirm the altered expressions at the protein level and/or their functional activity.2+ deficiency, as found in the Western population, is sufficient to modulate the gene expression of major pathways, mostly related to energy metabolism, proteostasis, autophagy, and mitochondrial dynamics in the skeletal muscle. Consequently, supplementing Mg2+ in Mg2+-deficient individuals might be a simple and costless countermeasure to maintain healthy muscles and metabolic balance.Our results emphasize that even a mild Mg