264 research outputs found

    An evidence map and synthesis review with meta-analysis on the risk of incisional hernia in colorectal surgery with standard closure.

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    Purpose To assess the incidence of incisional hernia (IH) across various type of incisions in colorectal surgery (CS) creating a map of evidence to define research trends, gaps and areas of future interest. Methods Systematic review of PubMed and Scopus from 2010 onwards. Studies included both open (OS) and laparoscopic (LS). The primary outcome was incidence of IH 12 months after index procedure, secondary outcomes were the study features and their influence on reported proportion of IH. Random effects models were used to calculate pooled proportions. Meta-regression models were performed to explore heterogeneity. Results Ninetyone studies were included reporting 6473 IH. The pooled proportions of IH for OS were 0.35 (95% CI 0.27–0.44) I2 0% in midline laparotomies and 0.02 (95% CI 0.00–0.07), I2 52% for off-midline. In case of LS the pooled proportion of IH for midline extraction sites were 0.10 (95% CI 0.07–0.16), I2 58% and 0.04 (95% CI 0.03–0.06), I2 86% in case of off-midline. In Port-site IH was 0.02 (95% CI 0.01–0.04), I2 82%, and for single incision surgery (SILS) of 0.06—95% CI 0.02–0.15, I2 81%. In case of stoma reversal sites was 0.20 (95% CI 0.16–0.24). Conclusion Midline laparotomies and stoma reversal sites are at high risk for IH and should be considered in research of preventive strategies of closure. After laparoscopic approach IH happens mainly by extraction sites incisions specially midline and also represent an important area of analysis.pre-print3102 K

    Preventing incisional ventral hernias: important for patients but ignored by surgical specialities? A critical review.

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    Purpose Incisional ventral hernias (IHs) are a common complication across all surgical specialities requiring access to the abdomen, pelvis, and retroperitoneum. This public health issue continues to be widely ignored, resulting in appreciable morbidity and expenses. In this critical review, the issue is explored by an interdisciplinary group. Methods A group of European surgeons encompassing representatives from abdominal wall, vascular, urological, gynecological, colorectal and hepato-pancreatico-biliary surgery have reviewed the occurrence of His in these disciplines. Results Incisional hernias are a major public health issue with appreciable morbidity and cost implications. General surgeons are commonly called upon to repair IHs following an initial operation by others. Measures that may collectively reduce the frequency of IH across specialities include better planning and preparation (e.g. a fit patient, no time pressure, an experienced operator). A minimally invasive technique should be employed where appropriate. Our main recommendations in midline incisions include using the ‘small bites’ suture technique with a ≥ 4:1 suture-to-wound length, and adding prophylactic mesh augmentation in patients more likely to suffer herniation. For off-midline incisions, more research of this problem is essential. Conclusion Meticulous closure of the incision is significant for every patient. Raising awareness of the His is necessary in all surgical disciplines that work withing the abdomen or retroperitoneum. Across all specialties, surgeons should aim for a < 10% IH rate.pre-print146 K

    First-in-human real-time AI-assisted instrument deocclusion during augmented reality robotic surgery

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    The integration of Augmented Reality (AR) into daily surgical practice is withheld by the correct registration of pre-operative data. This includes intelligent 3D model superposition whilst simultaneously handling real and virtual occlusions caused by the AR overlay. Occlusions can negatively impact surgical safety and as such deteriorate rather than improve surgical care. Robotic surgery is particularly suited to tackle these integration challenges in a stepwise approach as the robotic console allows for different inputs to be displayed in parallel to the surgeon. Nevertheless, real-time de-occlusion requires extensive computational resources which further complicates clinical integration. This work tackles the problem of instrument occlusion and presents, to the authors' best knowledge, the first-in-human on edge deployment of a real-time binary segmentation pipeline during three robot-assisted surgeries: partial nephrectomy, migrated endovascular stent removal, and liver metastasectomy. To this end, a state-of-the-art real-time segmentation and 3D model pipeline was implemented and presented to the surgeon during live surgery. The pipeline allows real-time binary segmentation of 37 non-organic surgical items, which are never occluded during AR. The application features real-time manual 3D model manipulation for correct soft tissue alignment. The proposed pipeline can contribute towards surgical safety, ergonomics, and acceptance of AR in minimally invasive surgery.This works presents the first-in-human edge deployment of a real-time AI-enabled augmented reality (AR) pipeline in robotic surgery. The application uses a binary segmentation model to effectively identify over 37 classes of non-organic items in the surgical scene, and uses this information to create an overlay visualization, solving the instrument occlusion problem, and preventing the possibly hazardous situation this implies, as well as adding a sense of depth to the AR. The solution is used during three real surgeries and segmentation results, application performance as well as qualitative surgical feedback are discussed.###imag

    Improving Augmented Reality Through Deep Learning: Real-time Instrument Delineation in Robotic Renal Surgery

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    Several barriers prevent the integration and adoption of augmented reality (AR) in robotic renal surgery despite the increased availability of virtual three-dimensional (3D) models. Apart from correct model alignment and deformation, not all instruments are clearly visible in AR. Superimposition of a 3D model on top of the surgical stream, including the instruments, can result in a potentially hazardous surgical situation. We demonstrate real-time instrument detection during AR-guided robot-assisted partial nephrectomy and show the generalization of our algorithm to AR-guided robot-assisted kidney transplantation. We developed an algorithm using deep learning networks to detect all nonorganic items. This algorithm learned to extract this information for 65 927 manually labeled instruments on 15 100 frames. Our setup, which runs on a standalone laptop, was deployed in three different hospitals and used by four different surgeons. Instrument detection is a simple and feasible way to enhance the safety of AR-guided surgery. Future investigations should strive to optimize efficient video processing to minimize the 0.5-s delay currently experienced. General AR applications also need further optimization, including detection and tracking of organ deformation, for full clinical implementation

    A New Method to Address Unmet Needs for Extracting Individual Cell Migration Features from a Large Number of Cells Embedded in 3D Volumes

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    Background: In vitro cell observation has been widely used by biologists and pharmacologists for screening molecule-induced effects on cancer cells. Computer-assisted time-lapse microscopy enables automated live cell imaging in vitro, enabling cell behavior characterization through image analysis, in particular regarding cell migration. In this context, 3D cell assays in transparent matrix gels have been developed to provide more realistic in vitro 3D environments for monitoring cell migration (fundamentally different from cell motility behavior observed in 2D), which is related to the spread of cancer and metastases. Methodology/Principal Findings: In this paper we propose an improved automated tracking method that is designed to robustly and individually follow a large number of unlabeled cells observed under phase-contrast microscopy in 3D gels. The method automatically detects and tracks individual cells across a sequence of acquired volumes, using a template matching filtering method that in turn allows for robust detection and mean-shift tracking. The robustness of the method results from detecting and managing the cases where two cell (mean-shift) trackers converge to the same point. The resulting trajectories quantify cell migration through statistical analysis of 3D trajectory descriptors. We manually validated the method and observed efficient cell detection and a low tracking error rate (6%). We also applied the method in a real biological experiment where the pro-migratory effects of hyaluronic acid (HA) were analyzed on brain cancer cells. Using collagen gels with increased HA proportions, we were able to evidence a dose-response effect on cell migration abilities. Conclusions/Significance: The developed method enables biomedical researchers to automatically and robustly quantify the pro- or anti-migratory effects of different experimental conditions on unlabeled cell cultures in a 3D environment. © 2011 Adanja et al.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Rapid and adaptive evolution of MHC genes under parasite selection in experimental vertebrate populations

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    The genes of the major histocompatibility complex are the most polymorphic genes in vertebrates, with more than 1,000 alleles described in human populations. How this polymorphism is maintained, however, remains an evolutionary puzzle. Major histocompatibility complex genes have a crucial function in the adaptive immune system by presenting parasite-derived antigens to T lymphocytes. Because of this function, varying parasite-mediated selection has been proposed as a major evolutionary force for maintaining major histocompatibility complex polymorphism. A necessary prerequisite of such a balancing selection process is rapid major histocompatibility complex allele frequency shifts resulting from emerging selection by a specific parasite. Here we show in six experimental populations of sticklebacks, each exposed to one of two different parasites, that only those major histocompatibility complex alleles providing resistance to the respective specific parasite increased in frequency in the next host generation. This result demonstrates experimentally that varying parasite selection causes rapid adaptive evolutionary changes, thus facilitating the maintenance of major histocompatibility complex polymorphism

    Robotic kidney transplantation using right-versus left-sided grafts from living donors: an european multicentre experience (ERUS-RAKT working group)

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    Introduction: RAKT from living donors (LD) is increasingly performedin selected centers with experience in robotic surgery and kidneytransplantation (KT). Of note, KT from LD using right-sided graft (RSG)is challenging due to the brevity of the right renal vein and has beenassociated with a higher riskof perioperative complications in selectedseries. In this scenario, RAKT may facilitate the performance ofvascular anastomoses in case of short renal vessels thanks to theadvantages of the robotic platform. However, the evidence on thesafety and feasibility of RAKT using RSGs is lacking. The aim of thisstudy is to compare the surgical andearly perioperative outcomes after RAKT from LD using right- vs. left-sided grafts in a large prospectivemulticenter cohort (ERUS-RAKT working group)

    Red Queen Coevolution on Fitness Landscapes

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    Species do not merely evolve, they also coevolve with other organisms. Coevolution is a major force driving interacting species to continuously evolve ex- ploring their fitness landscapes. Coevolution involves the coupling of species fit- ness landscapes, linking species genetic changes with their inter-specific ecological interactions. Here we first introduce the Red Queen hypothesis of evolution com- menting on some theoretical aspects and empirical evidences. As an introduction to the fitness landscape concept, we review key issues on evolution on simple and rugged fitness landscapes. Then we present key modeling examples of coevolution on different fitness landscapes at different scales, from RNA viruses to complex ecosystems and macroevolution.Comment: 40 pages, 12 figures. To appear in "Recent Advances in the Theory and Application of Fitness Landscapes" (H. Richter and A. Engelbrecht, eds.). Springer Series in Emergence, Complexity, and Computation, 201

    Fat1 deletion promotes hybrid EMT state, tumour stemness and metastasis

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    FAT1, which encodes a protocadherin, is one of the most frequently mutated genes in human cancers1–5. However, the role and the molecular mechanisms by which FAT1 mutations control tumour initiation and progression are poorly understood. Here, using mouse models of skin squamous cell carcinoma and lung tumours, we found that deletion of Fat1 accelerates tumour initiation and malignant progression and promotes a hybrid epithelial-to-mesenchymal transition (EMT) phenotype. We also found this hybrid EMT state in FAT1-mutated human squamous cell carcinomas. Skin squamous cell carcinomas in which Fat1 was deleted presented increased tumour stemness and spontaneous metastasis. We performed transcriptional and chromatin profiling combined with proteomic analyses and mechanistic studies, which revealed that loss of function of FAT1 activates a CAMK2–CD44–SRC axis that promotes YAP1 nuclear translocation and ZEB1 expression that stimulates the mesenchymal state. This loss of function also inactivates EZH2, promoting SOX2 expression, which sustains the epithelial state. Our comprehensive analysis identified drug resistance and vulnerabilities in FAT1-deficient tumours, which have important implications for cancer therapy. Our studies reveal that, in mouse and human squamous cell carcinoma, loss of function of FAT1 promotes tumour initiation, progression, invasiveness, stemness and metastasis through the induction of a hybrid EMT state
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