Arteriogenesis versus angiogenesis: similarities and differences

Cardiovascular diseases account for more than half of total mortality before the age of 75 in industrialized countries. To develop therapies promoting the compensatory growth of blood vessels could be superior to palliative surgical surgical interventions. Therefore, much effort has been put into investigating underlying mechanisms. Depending on the initial trigger, growth of blood vessels in adult organisms proceeds via two major processes, angiogenesis and arteriogenesis. While angiogenesis is induced by hypoxia and results in new capillaries, arteriogenesis is induced by physical forces, most importantly fluid shear stress. Consequently, chronically elevated fluid shear stress was found to be the strongest trigger under experimental conditions. Arteriogenesis describes the remodelling of pre-existing arterio-arteriolar anastomoses to completely developed and functional arteries. In both growth processes, enlargement of vascular wall structures was proposed to be covered by proliferation of existing wall cells. Recently, increasing evidence emerges, implicating a pivotal role for circulating cells, above all blood monocytes, in vascular growth processes. Since it has been shown that monocytes/macrophage release a cocktail of chemokines, growth factors and proteases involved in vascular growth, their contribution seems to be of a paracrine fashion. A similar role is currently discussed for various populations of bone-marrow derived stem cells and endothelial progenitors. In contrast, the initial hypothesis that these cells -after undergoing a (trans-)differentiation- contribute by a structural integration into the growing vessel wall, is increasingly challenged

Klinischer Behandlungspfad Carotisstenose : Evaluation im Ländervergleich ; Poster

Poster Einleitung Im Rahmen effizienzsteigernder Maßnahmen sind klinische Behandlungspfade unter DRG- Bedingungen und im Rahmen der Qualitätssicherung wichtige Instrumente. Material und Methoden Aus der Analyse zweier erfahrungsbasierter klinischer Behandlungspfade in Frankfurt/D und Newcastle/GB wurde ein halbstandardisierter clinical pathway Carotisstenose entwickelt, der der heterogenen Befundkonstellation bei Aufnahme, den unterschiedlichen klinischen Stadien der Erkrankung und den individuellen Patientenbedürfnissen Rechnung trägt. Es wurden dazu zwei Gruppen mit je 25 konsekutiv in Frankfurt/D ( Gruppe FrankfurtI) und New Castle/GB ( Gruppe New Castle )operierten Patienten retrospektiv analysiert.Aus den retrospektiv erhobenen Daten wurde ein stadienbezogener und der Zuweisersituation gerecht werdender klinischer Behandlungspfad erstellt, der anhand von 20 konsekutiv operierten Patienten, davon 60 % im Stadium IV der Erkrankung, ( Gruppe FrankfurtII ) analysiert wurde. Ergebnisse In Frankfurt 1 wurde 21 mal eine Eversions-TEA und 4 mal eine TEA/ Patchplastik angewendet, 62 % der Patienten befanden sich im Stadium 1 der Erkrankung, ,65 % erhielten präoperativ eine i.a.DSA der supraaortalen Äste ,100% eine Duplexsonografie und eine CCT; postoperativ fielen insgesamt 12 Intensiv- Pflegetage an sowie eine Revision aufgrund einer Nachblutung. In der Gruppe New Castle befanden sich 68% der Patienten in einem klinischen Stadium 2,es wurde 25 mal offen thrombendarteriektomiert, davon 21 mal mit Direktnaht verschlossen und 4 mal mit Patchplastik, alle Patienten erhielten präoperativ eine CT- Angiografie und eine Duplexsonografie; postoperativ fiel 1 Intensivpflegetag an und eine Revision wegen Nachblutung. Die Morbiditäts-/ Mortalitätsrate betrug in beiden Gruppen 0%. Betriebswirtschaftlich wurden bei einer Liegedauer von durchschnittlich 10 Tagen in Frankfurt 1 tatsächliche Kosten von 2768.96€ pro Patient ermittelt, in New Castle,bei einer Liegedauer von durchschnittlich 5 Tagen und einer differenten Kostenstruktur von 2510.56 €. In der Gruppe Frankfurt 2 wurde 11mal eine TEA mit Patchplastik und 9 mal eine Eversions-TEA durchgeführt, alle Patienten erhielten präoperativ eine Duplexsonografie und eine CCT , postoperativ fielen insgesamt 6 Intensivtage an, es wurde nicht revidiert, die Morbiditäts-/Mortalitätsrate lag ebenfalls bei 0%. Durch Einführung eines klinischen Behandlungspfades wurde also die Liegedauer in Frankfurt um 40 % reduziert sowie die tatsächlichen Kosten auf 2384.41€ pro Fall und damit im Mittel um 14 % gemindert. Schlussfolgerung Unter DRG-Bedingungen trägt daher die Anwendung eines klinischen Behandlungspfades in der Carotischirurgie zu einer Verbesserung der Erlössituation ohne Qualitätseinbuße bei

Altered in-stent hemodynamics may cause erroneous upgrading of moderate carotid artery restenosis when evaluated by duplex ultrasound

ObjectiveTo assess the influence of stent application on in-stent hemodynamics under standardized conditions.MethodsOvine common carotid arteries before and after stent (6 × 40 mm, sinus-Carotid-RXt, combined open-closed cell design; Optimed, Ettlingen, Germany) application were used. Plastic tubes, 10 mm in length, simulating stenosis were placed in the middle of the applied stent to induce different degrees of stenosis (moderate 57.8% and severe 76.4%). Flow velocity and dynamic compliance were, respectively, measured with ultrasound and laser scan; proximal, in-stent, and distal to the stented arterial segment (1 cm proximal and distal) in a pulsatile ex vivo circulation system.ResultsStent insertion caused the in-stent peak systolic velocity to increase 22% without stenosis, 31% with moderate stenosis, and 23% with severe stenosis. Stent insertion without stenosis caused no significant increase in in-stent end-diastolic velocity (EDV) but a 17% increase with moderate stenosis. In severe stenosis, EDV was increased 56% proximal to the stenosis. Compliance was reduced threefold in the middle of the stented arterial segment where flow velocity was significantly increased.ConclusionsWith or without stenosis, stent introduction caused the in-stent peak systolic velocity to become significantly elevated compared with a nonstented area. EDV was also increased by stent insertion in the case of moderate stenosis. The stent-induced compliance reduction may be causal for the increase in flow velocity since the stent-induced flow velocity elevation appeared in the stented area with low compliance. Because of altered hemodynamics caused by stent introduction when measured by duplex ultrasound, caution is prudent in concluding that carotid artery stenting is associated with a higher restenosis rate than carotid endarterectomy. Mistakenly upgrading moderate to severe restenosis could result in unnecessary reintervention.Clinical RelevanceClinical experience and prior studies support the supposition that restenosis after carotid artery stenting in carotid lesions displays erroneously elevated velocity when evaluated by duplex ultrasound (DUS), thus contributing to misleading interpretation of the degree of stenosis. This study, in contrast to studies of other groups, employs exactly the same conditions to measure flow with DUS in an unstented and then stented section of the carotid artery. Since DUS is the first-choice tool for carotid artery evaluation, knowledge about inexactness of the method is essential to avoid errors in treatment or follow-up decisions

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

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

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

Editorial

Research in vascular medicine mainly involves developing drugs and prosthetic devices as well as conducting clinical outcome research and basic science to gain knowledge about vascular biology. But there is more. In the current issue several projects divulge how research and development in the vascular field extends beyond these bounds. ..