Tissue Sampling Guides for Porcine Biomedical Models

This article provides guidelines for organ and tissue sampling adapted to porcine animal models in translational medical research. Detailed protocols for the determination of sampling locations and numbers as well as recommendations on the orientation, size, and trimming direction of samples from approximate to 50 different porcine organs and tissues are provided in the Supplementary Material. The proposed sampling protocols include the generation of samples suitable for subsequent qualitative and quantitative analyses, including cryohistology, paraffin, and plastic histology;immunohistochemistry;in situ hybridization;electron microscopy;and quantitative stereology as well as molecular analyses of DNA, RNA, proteins, metabolites, and electrolytes. With regard to the planned extent of sampling efforts, time, and personnel expenses, and dependent upon the scheduled analyses, different protocols are provided. These protocols are adjusted for (I) routine screenings, as used in general toxicity studies or in analyses of gene expression patterns or histopathological organ alterations, (II) advanced analyses of single organs/tissues, and (III) large-scale sampling procedures to be applied in biobank projects. Providing a robust reference for studies of porcine models, the described protocols will ensure the efficiency of sampling, the systematic recovery of high-quality samples representing the entire organ or tissue as well as the intra-/interstudy comparability and reproducibility of results

Hyperspectral abdominal laparoscopy with real-time quantitative tissue oxygenation imaging: a live porcine study

BackgroundIschaemia is a critical complication, and can result in poor surgical outcomes. While intra-operative overt ischaemia can be perceived with the naked eye, timely recognition of borderline perfusion can prevent post-operative ischaemic complications, which is particularly relevant for colorectal anastomoses. Consequently, there is a clinical need for new technologies to intra-operatively assess tissue oxygenation (indicative of end organ perfusion), with minimal disruption to the surgical workflow. Here we present a hyperspectral imaging (HSI) system for laparoscopic surgery. This system provides live, easy to interpret, tissue oxygenation (StO2) maps with associated quantitative values.MethodsWhite light view and tissue oxygenation maps were reconstructed from a protoype laparoscopic Hyperspectral Surgical System (HSS). First, in a live porcine model (55 kg female), the mesentery of a small bowel loop was temporarily occluded with a laparoscopic grasper, then released whilst being imaged with HSI. The quantitative StO2 values obtained from the HSS were compared with those of a non-invasive tissue oximetry probe (Moor VMS-Oxy, Moor Instruments Ltd, United Kingdom). Secondly, mimicking a laparoscopic colon resection and anastomosis, the colorectal junction was mobilised laparoscopically, exteriorised, transected, anastomosed and repositioned in the abdominal cavity. In order to compare healthy and ischaemic colon, the distal part was intentionally devascularised. Tissue oxygenation maps were compared with indocyanine green fluorescence angiography (ICG-FA) of the anastomotic region.ResultsThe HSS was used as the primary scope to complete a laparoscopic colorectal anastomosis, providing a simultaneous white light view and hyperspectral information. Quantitative results from small bowel imaging were shown to correlate with measurements from the superficial tissue oximetry probe. Real-time tissue oxygenation maps were shown to visually correlate with ICG-FA.ConclusionThe HSS can guide laparoscopic surgical procedures whilst providing visual and quantitative tissue oxygenation information in a live animal model. This paves the way for further studies to assess clinical applications

Development of an ontology for laparoscopic transabdominal adrenalectomy via a comprehensive modified Delphi survey and its validation on a multicentric pilot data set for surgical training and future video analysis with machine learning algorithms

International audienceSurgical technique is essential to ensure safe minimally invasive adrenalectomy. Due to the relative rarity of adrenal surgery, it is challenging to ensure adequate exposure in surgical training. Surgical video analysis supports auto-evaluation, expert assessment and could be a target for automatization. The developed ontology was validated by a European expert consensus and is applicable across the surgical techniques encountered in all participating centres, with an exemplary demonstration in bi-centric recordings. Standardization of adrenalectomy video analysis may foster surgical training and enable machine learning training for automated safety alerts

Safety and vision outcomes of subretinal gene supplementation therapy in PDE6A-associated retinitis pigmentosa: a non-randomised controlled trial

Purpose: PDE6A-associated retinitis pigmentosa (RP) is a rare inherited retinal disease leading to severe vision loss and blindness, with no available treatment. This study assessed the safety and vision outcomes of a gene therapy using an adeno-associated virus (AAV) vector encoding PDE6A (AAV8.hPDE6A). Methods: In an open-label, non-randomised controlled phase I/IIa trial, nine patients with biallelic PDE6A variants received a single subretinal injection of AAV8.hPDE6A. Doses were either 1.0×10¹⁰ (n=6) or 5.0×10¹⁰ (n=3) total vector genomes. Safety was the primary endpoint, assessed via clinical examinations, laboratory analyses and optical coherence tomography imaging. Secondary outcomes included changes in visual function, such as best corrected visual acuity (BCVA), contrast sensitivity, colour perception, dark adaptation thresholds, visual fields, patient-reported outcomes and chromatic pupil campimetry over 1 year. Results: The mean patient age was 40.1 years, with baseline BCVA ranging from 40 to 82 letters (0.9–0.1 logMAR). No systemic adverse events occurred, and most ocular events resolved without treatment. Persistent adverse events included small peripheral atrophic areas (n=2), disturbed colour discrimination (n=3), cataract (n=1), slight central retinal thinning (n=5) and moderate visual acuity loss (n=2, 1 in each dose group). BCVA, full-field stimulus thresholds and other visual function measures showed statistically non-significant changes, with a trend towards worsening of retinal sensitivity in the treated eyes. Conclusion: Subretinal gene therapy with AAV8.hPDE6A did not improve visual function over 1 year and posed risks, including central retinal thinning and visual acuity decline. This is in contrast to the safety and efficacy profile established in preclinical models

Surgeons' perspectives on artificial intelligence to support clinical decision-making in trauma and emergency contexts: results from an international survey

Background Artificial intelligence (AI) is gaining traction in medicine and surgery. AI-based applications can offer tools to examine high-volume data to inform predictive analytics that supports complex decision-making processes. Time-sensitive trauma and emergency contexts are often challenging. The study aims to investigate trauma and emergency surgeons’ knowledge and perception of using AI-based tools in clinical decision-making processes. Methods An online survey grounded on literature regarding AI-enabled surgical decision-making aids was created by a multidisciplinary committee and endorsed by the World Society of Emergency Surgery (WSES). The survey was advertised to 917 WSES members through the society’s website and Twitter profile. Results 650 surgeons from 71 countries in five continents participated in the survey. Results depict the presence of technology enthusiasts and skeptics and surgeons' preference toward more classical decision-making aids like clinical guidelines, traditional training, and the support of their multidisciplinary colleagues. A lack of knowledge about several AI-related aspects emerges and is associated with mistrust. Discussion The trauma and emergency surgical community is divided into those who firmly believe in the potential of AI and those who do not understand or trust AI-enabled surgical decision-making aids. Academic societies and surgical training programs should promote a foundational, working knowledge of clinical AI

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Evaluation of visceral and anastomotic perfusion by means of fluorescence-based enhanced reality

The fluorescence-based enhanced reality approach is used to quantify fluorescent signal dynamics and superimpose the perfusion cartography onto laparoscopic images in real time. A colonic ischemia model was chosen to differentiate between different types of ischemia and determine the extension of an ischemic zone in the different layers of the colonic wall. The evaluation of fluorescence dynamics associated with a machine learning approach made it possible to distinguish between arterial and venous ischemia with a good prediction rate. In the second study, quantitative perfusion assessment showed that the extent of ischemia was significantly larger on the mucosal side, and may be underestimated with an exclusive analysis of the serosal side. Two further studies have revealed that fluorescence imaging can guide the surgeon in real time during minimally invasive adrenal surgery, and that quantitative software fluorescence analysis facilitates the distinction between vascularized and ischemic segments.La technique de réalité augmentée basée sur la fluorescence permet de quantifier la dynamique d’un signal fluorescent et de superposer une cartographie de perfusion aux images laparoscopiques en temps réel. Un modèle d’ischémie colique a été choisi afin de différencier différents types d’ischémie et l’extension d’une zone ischémique dans les différentes couches de la paroi. L’évaluation de la dynamique de fluorescence assistée par logiciel et couplée à une approche d’apprentissage automatique a permis de faire la distinction entre une ischémie d’origine artérielle et d’origine veineuse avec un bon taux de prédiction. Dans la seconde étude colique, les cartographies de perfusion ont clairement mis en évidence que l’étendue d’ischémie était significativement plus large du côté muqueux et risquait d’être sous-estimée avec une analyse exclusive du côté séreux. Deux études ont démontré que la technique d’imagerie par fluorescence permet de guider le chirurgien en temps réel au cours d’une chirurgie mini-invasive des glandes surrénales et que l’analyse quantitative effectuée avec le logiciel facilite la distinction entre les segments vascularisés et ischémiques

CpG island methylation patterns in patients with chronic lymphocytic leukemia

International audienc