Ultrasound-based image guidance for endovascular interventions has long been propagated as safe and (cost)-effective in many respects. IVUS guidance has also been shown to be superior to angiographic guidance in aortic disease, both in terms of imaging and radiation reduction. This book discusses the value and potential applications of IVUS in aorto-iliac pathologies. Part I explains the potential risks and side effects of using X-rays for patients and staff. The current status of IVUS imaging and the requirements for successful use of this tool are presented. Part II focuses on when and how to use IVUS guidance in the aortic and pelvic segments. In addition to the presentation of the technical equipment, recommendations are given for the implementation of IVUS in the daily routine and for image generation, procedural sequences and interpretation of the findings based on the display on the IVUS monitor. This book is a useful guide for physicians and other staff members dealing routinely with radiation-based imaging in the operative setting or the angiosuite. It will also raise the reader's awareness for the X-ray-associated risks and available solutions for improving radiation safety in the OR and the procedural and outcome quality.

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Part I 1.Introduction12 1.1.US for access to target vessels12 1.2.US guidance for endovascular procedures13 1.3.Therapeutic use of US for endovascular reconstruction13 1.4.Why should we perform IVUS guidance for aortic and aorto-iliac procedures13 2.Radiation safety issues and risk awareness16 2.1.Revised radiation safety directives and guidelines 2020-202216 2.2.Radiation safety items in the daily routine: staff training16 2.3.Radiation protection items in the daily routine17 2.4.Personalized radiation protection equipment18 2.5.Reduction of the individual radiation exposure20 2.5.1.Influence of radiation source position and individual behavior20 2.5.2.Influence of room geometry and procedural workflow on staff radiation exposure21 2.5.3.Projection angle and radiation safety: steady AP-projection for optimal radiation protection25 3.Iodinated Contrast Media (ICM) and procedure-related renal side effects30 3.1.CIN: Contrast-Induced Nephropathy31 3.1.1.Definition of CIN31 3.1.2.Pathophysiology of CIN31 3.1.3.Risk factors for CIN and prevention31 3.1.4.Differential diagnosis of CIN32 3.1.5.Strategies for CIN prevention33 3.1.6.IVUS for CIN prevention33 3.2.Acute kidney injury vs. CIN34 4.Software and hardware solutions for radiation dose / contrast media reduction and workflow improvement37 4.1.ClarityIQ™ and image noise reduction37 4.2.Image fusion solutions37 4.3.FORS (fiberoptic real shape imaging)38 4.4.Simulation-based endovascular (and open surgery) radiation protection training38 Part II 5.IVUS image guidance for endovascular procedures in respect to current radiation safety guidelines42 5.1.The revised ESVS radiation guidelines and the role of IVUS42 5.2.Decision making for IVUS use43 5.3.What is the current state of IVUS image guidance in the different vascular territories? Why use IVUS at all?44 5.3.1.IVUS for Percutaneous Coronary Interventions (PCI)44 5.3.2.IVUS for endovenous procedures44 5.3.3.IVUS for PAD45 5.3.4.Non-clinical aspects of IVUS: Cost effectiveness calculations for PVI and PCI45 5.3.5.IVUS and radiation/procedural safety46 6.Current technical state of IVUS image guidance50 6.1.Comparison of IVUS vs. angiographic imaging50 6.2.Catheter portfolio and technical specifications53 6.2.1.Technical basics of IV/US imaging53 6.2.2.IVUS catheter portfolio53 6.2.3.Technical specifications of IVUS catheters56 6.2.4.Imaging techniques and image information content59 6.2.4.1.ChromaFlo™59 6.2.4.2.VH IVUS59 6.3.Current options for image processing60 6.3.1.Image processing with Intrasight 5S61 6.4.Standards of Procedure (SOP) for IVUS use63 6.4.1.SOP for the hybrid room64 6.4.2.SOP for the standard operating room (constricted room)65 6.5.Team challenge IVUS66 6.5.1.Team challenge IVUS catheter use66 6.5.2.Team challenge Pioneer Plus catheter use66 7.IVUS for EVAR69 7.1.Published IVUS data for TEVAR69 7.2.What are the key factors for advanced image guidance in TEVAR or aorto-iliac PAD procedures?70 7.3.Target vessel mapping and sealing zone definition by intraluminal cross-sectional imaging72 7.3.1.Parallaxes and IVUS73 7.4.SOPs for IVUS guidance during TEVAR / PAD74 7.4.1.EVAR-SOP in the local setting74 7.4.1.1.Vessel access74 7.4.1.2.Pullback maneuver with IVUS and image processing74 7.4.1.3.Mapping of the target vessels75 7.4.1.4.Catheter protection during graft deployment75 7.4.1.5.IVUS completion control75 7.4.1.6.Workspace setting for TEVAR / PAD75 7.5.IVUS image interpretation78 7.5.1.Image interpretation prior to infrarenal endograft placement79 7.5.2.Interpretation of IVUS images after endograft deployment (completion of IVUS pullback)83 7.5.3.Sealing length84 7.5.4.Endoleak detection with IVUS86 7.6.IVUS benefits in terms of prevention of early complications87 7.7.IVUS and radiation safety87 8.IVUS for TEVAR (for aneurysmal disease, aortic dissections, and other pathologies)93 8.1.Where and when IVUS is useful93 8.2.Procedural pathways and imaging properties for IVUS and angiography in different pathologies94 8.3.Available evidence concerning IVUS image guidance for thoracic endograft placement95 8.4.IVUS imaging quality for the different TEVAR modalities and their challenges99 8.5.IVUS image guidance workflow and image interpretation99 8.5.1.Femoral artery access99 8.5.2.Advancement of devices99 8.5.3.IVUS vs. CTA centerline99 8.5.4.IVUS image guidance in dissections: the gold standard for reliability?100 8.5.5.Procedural workflow for pathologies in the descending thoracic aorta105 8.5.6.Specific findings using IVUS106 8.5.7.Advantages of IVUS vs. deficits of angiography in completion imaging106 8.5.7.1.Bird beak sign106 8.5.7.2.Infolding of grafts108 8.5.7.3.Graft crimping108 8.5.7.4.Imminent stroke risk of arch angiography110 8.5.7.5.Visualization of intra- and extraluminal structures110 8.6.Conclusions113 9.IVUS image guidance for aortoiliac occlusive disease116 9.1.Procedural and clinical outcome of IVUS-guided revascularizations116 9.2.Technical requirements and SOPs for IVUS image guidance for arterial occlusive disease116 9.2.1.Procedural pathway for IVUS mapping and completion control for aorto-iliac stenosis117 9.2.1.1.Procedural steps for IVUS guidance119 9.3.Image interpretation121 9.4.Radiation safety issues in aorto-iliac procedures123 9.5.Conclusions126 10.Interpretation and misinterpretation of IVUS images128 10.1.Particular problems of IVUS image guidance and dedicated bail-out proposals128 10.1.1.Sonic shadow vs. vessel lumen128 10.2.Imaging details and decision making129 10.3.Orientation for target vessel definition / mapping and exact device129 10.3.1.What are ambiguous or unambiguous markers?129 10.3.2.Anatomy of the renal vein and misleading interpretation129 10.3.3.Artefacts originating from the catheter tip132 10.3.4.Artefacts originating from implants133 10.3.5.What about orientation and interpretation in severely calcified lesions or after device placement?133 10.3.6.Interpretation of dissection vs. artefacts in different vessels134 10.3.6.1.IVUS advantages in dissection detection during PAD treatment136