Quantifizierung des dreidimensionalen glomerulären Kapillarsystems von Schweinen mittels der Mikro– und Nano– Computertomographie

Hintergrund: Die vorliegende Arbeit präsentiert die dreidimensionale Darstellung und Quantifizierung des renalen Gefäßsystems von Schlachthausschweinen und domestizierten Minipigs mittels der Mikro- und Nano – CT. Material und Methoden: Um den renalen porcinen Gefäßbaum dreidimensional darzustellen und zu quantifizieren, werden zwei Studienkollektive aus fünf Schlachthausschweinen (Studienpopulation: 1, Alter: 6 Monate; Gewicht: 120 kg) und sieben domestizierten Minipigs (Studienpopulation: 2, Alter: 25 Wochen, Gewicht: 45 – 55 kg) gebildet. Die Nieren werden entweder mit einer Mischung aus BaSO4 und Gelantine (SP 1) oder mit Microfil® (SP 2) perfundiert. Anschließend werden aus den Nieren Stanzen gewonnen, diese fixiert und mittels der Mikro- und Nano – CT gescannt. Mit der Mikro – CT und Nano – CT werden der glomeruläre Durchmesser (mm), Fläche (mm2), Volumen (mm3) und die Gesamtanzahl der Glomeruli pro Fläche (n/mm2) bestimmt. Mit der Nano – CT wird zusätzlich zu den genannten Parametern das intraglomeruläre Kapillarvolumen (mm3) quantifiziert. Die gewonnenen Daten werden mit der Histologie verglichen. Ergebnisse: In der Analyse der Daten des Studienkollektivs 1 stellt sich eine signifikante Zunahme der Messwerte ausgehend von der histomorphometrischen Untersuchung über die NCT zu der &#956;CT – Untersuchung (0,231 &#61617;&#61472;0,03 mm, 0,033 &#61617;&#61472;0,01 mm²; 0,252 &#61617;&#61472;0,028 mm, 0,041 &#61617;&#61472;0,01 mm², 0,0057 &#61617;&#61472;0,0025 mm3; 0,269 &#61617;&#61472;0,037 mm, 0,047 &#61617;&#61472;0,01mm², 0,0067 &#61617;&#61472;0,0025 mm3, p < 0,001). Die quantitative Analyse des glomerulären und kapillären Volumens (SK 1) und Fläche (SK 2) zeigt eine signifikante Korrelation der Parameter zueinander (r2 = 0,97, r2 = 0,19 ). Die Nano – CT – Untersuchungen der Studien-population 2 ergeben ebenfalls signifikant höhere Resultate als deren histologischen Korrelate (0,139 &#61617;&#61472;0,019 mm, 0,016 &#61617;&#61472;0,004 mm2, 0,12 &#61617;&#61472;0,02 mm, 0,011 &#61617;&#61472;0,003 mm2, p < 0,001). Schlussfolgerung Die Ergebnisse weisen auf einen potentiellen Nutzen der 3D – Visualisierung und Quantifikation mittels der Mikro- und Nano - CT zur Evaluierung glomerulärer und vaskulärer Anteile der Niere und könnten somit für die Erforschung renaler und hypertensiver Erkrankungen von Nutzen sein.Background: This study is designed to evaluate the feasibility for analysis of the kidney glomeruli capillary unit in adult and domestic pics using micro- and nano – CT imaging. Methods: Kidneys were harvested from five healthy hybrid pics (study population 1, 6 months of age; weight 120 kg) at a local slaughterhouse and seven kidneys from healthy domestic minipigs (study population 2, 25 weeks of age, weight 45 – 55 kg). They were infused either with a mixture of BaSO4 and gelatine (SP 1) or Microfil® (SP 2). Kidney samples were punched out, harvested and scanned with micro – CT and nano – CT. Diameter (mm) and cross-sectional area (mm2) of glomeruli were measured using micro – CT, nano – CT and histology. The capillary vessel volume (mm³) within single glomeruli was quantitated using nano – CT. Results were complemented by colocalized histology. Results: Within the study population 1 glomeruli diameter, crosssectional area and glomerulary volume increased significantly as measured by histology, nano – CT and micro – CT (0.231 &#61617;&#61472;0.03 mm, 0.033 &#61617;&#61472;0.01 mm²; 0.252 &#61617;&#61472;0.028 mm, 0.041 &#61617;&#61472;0.01 mm², 0.0057 &#61617;&#61472;0.0025 mm3; 0.269 &#61617;&#61472;0.037 mm, 0.047 &#61617;&#61472;0.01mm², 0.0067 &#61617;&#61472;0.0025 mm3, p < 0.001; respectively). Quantitative nano – CT analysis demonstrated a strong linear relationship of the volume of glomeruli and the capillary volume (r² = 0.97). In study population 2 the analysis shows comparable results relating to study population1. Nano – CT measurements demonstrate significant higher values as in histological analysis (0.139 &#61617;&#61472;0.019 mm, 0.016 &#61617;&#61472;0.004 mm2, 0.12 &#61617;&#61472;0.02 mm, 0.011 &#61617;&#61472;0.003 mm2, p < 0.001). The capillary surface area relates strongly to the glomerulary surface area (r2 = 0.19). Conclusion: These results demonstrate potential use of quantitative 3D micro- and nano – CT imaging to obtain information about glomeruli dimensions´ and vascularisation, which could be useful in animal models of kidney alterations

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