https://vascular.stanford.edu/content/dam/sm/vascular/documents/endovasc/guidelines/PIIS0741521406022968.pdf

Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II)

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic) A Collaborative Report from the American Association for Vascular Surgery/Society for Vascular Surgery,* Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease) Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation

/pdf/acc-aha-2005-practice-guidelines-for-the-management-of-4ltfid6e9i.pdf

ACC/AHA 2005 Practice Guidelines for the Management of Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic)

The physical principles underlying some current biomedical applications of magnetic nanoparticles are reviewed. Starting from well-known basic concepts, and drawing on examples from biology and biomedicine, the relevant physics of magnetic materials and their responses to applied magnetic fields are surveyed. The way these properties are controlled and used is illustrated with reference to (i) magnetic separation of labelled cells and other biological entities; (ii) therapeutic drug, gene and radionuclide delivery; (iii) radio frequency methods for the catabolism of tumours via hyperthermia; and (iv) contrast enhancement agents for magnetic resonance imaging applications. Future prospects are also discussed.

https://iopscience.iop.org/article/10.1088/0022-3727/36/13/201/pdf

Applications of magnetic nanoparticles in biomedicine

Atherosclerotic cardiovascular disease results in >19 million deaths annually, and coronary heart disease accounts for the majority of this toll. Despite major advances in treatment of coronary heart disease patients, a large number of victims of the disease who are apparently healthy die suddenly without prior symptoms. Available screening and diagnostic methods are insufficient to identify the victims before the event occurs. The recognition of the role of the vulnerable plaque has opened new avenues of opportunity in the field of cardiovascular medicine. This consensus document concludes the following. (1) Rupture-prone plaques are not the only vulnerable plaques. All types of atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression should be considered as vulnerable plaques. We propose a classification for clinical as well as pathological evaluation of vulnerable plaques. (2) Vulnerable plaques are not the only culprit factors for the development of acute coronary syndromes, myocardial infarction, and sudden cardiac death. Vulnerable blood (prone to thrombosis) and vulnerable myocardium (prone to fatal arrhythmia) play an important role in the outcome. Therefore, the term "vulnerable patient" may be more appropriate and is proposed now for the identification of subjects with high likelihood of developing cardiac events in the near future. (3) A quantitative method for cumulative risk assessment of vulnerable patients needs to be developed that may include variables based on plaque, blood, and myocardial vulnerability. In Part I of this consensus document, we cover the new definition of vulnerable plaque and its relationship with vulnerable patients. Part II of this consensus document focuses on vulnerable blood and vulnerable myocardium and provide an outline of overall risk assessment of vulnerable patients. Parts I and II are meant to provide a general consensus and overviews the new field of vulnerable patient. Recently developed assays (eg, C-reactive protein), imaging techniques (eg, CT and MRI), noninvasive electrophysiological tests (for vulnerable myocardium), and emerging catheters (to localize and characterize vulnerable plaque) in combination with future genomic and proteomic techniques will guide us in the search for vulnerable patients. It will also lead to the development and deployment of new therapies and ultimately to reduce the incidence of acute coronary syndromes and sudden cardiac death. We encourage healthcare policy makers to promote translational research for screening and treatment of vulnerable patients.

/pdf/from-vulnerable-plaque-to-vulnerable-patient-a-call-for-new-47rrnyxj2m.pdf

From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part II.

Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.

Transcatheter Electrosurgery: A Narrative Review

MRI-guided drug and cell injection therapies for heart disease

Effect of Leaflet Laceration on TAVR Fluid Mechanics and Comparison with SAVR

To the Editor, Mano and colleagues deserve credit for sharing their complication of transcaval transcatheter valve implantation (TAVI) access. Their report highlights several important lessons. During their case, a transcaval aortic 0.014′′ guidewire was introduced but the operators were unable to upsize to a TAVI guidewire, so they withdrew the guidewire and successfully completed transcaval TAVI at a supra‐renal aortic target. A postprocedure computed tomography (CT) revealed a pseudoaneurysm and aortocaval fistula at the first (abandoned) traversal site. The pseudoaneurysm was excluded with a transfemoral covered stent, and the patient was discharged home. In retrospect the complications appear related to a coregistration error and to an abandoned guidewire traversal. Elective transcaval TAVI should be planned on preprocedure CT to identify a sufficiently large calcium‐free traversal target for the transfemoral venous introducer sheath, without interposed structures such as bowel, and sufficiently far from renal and iliac branches to allow bailout covered stent implantation. The CT is used to identify specific traversal targets, fluoroscopic projection angles, select appropriately sized bailout devices, and to identify structures for co‐registering the CT and fluoroscopy. The last step, coregistration with known (“fiducial”) structures, can be confusing. We plan transcaval targets in relation to specific lumbar vertebrae, which should be uniquely identified in relation to other structures such as iliac crest or renal parenchyma. One rule‐of‐ thumb is that the top of the iliac crests typically corresponds to the L4–L5 lumbar interspace and to the aorto‐iliac bifurcation. We recommend that the aortic target be depicted in digital‐subtraction aortography in context of those fiducial structures, and that operators also view un‐subtracted or partial‐subtraction “landmark” modes before beginning traversal. In this case, the renal parenchymal blush evident in Mano's Figure 1A should alert the operators of a possible peri‐renal transcaval traversal, which is undesirable. The second challenge described here is inability to advance a transcaval microcatheter into the aorta after successful electrosurgical caval‐aortic guidewire entry. Typical traversal equipment assemblies—consisting of a coaxial stiff 0.014′′ guidewire inside a 0.014′′ microcatheter inside a 0.035′′ microcatheter, inside a short curved guiding catheter—are intended to upsize to a rigid Lunderquist‐style 0.035′′ guidewire and thereby deliver a transcaval TAVI introducer sheath. When the 0.014′′ microcatheter fails to deliver, small coronary or peripheral angioplasty balloon catheters usually successfully cross and dilatate, and allow intended escalation of microcatheter caliber until the 0.035′′ Lunderquist wire and transcaval introducer sheath are delivered. Countertraction via the aortic snare can be helpful. When angioplasty catheters fail, some have used laser or even rotational atherectomy [J Fredi, Personal Communication] devices across the aortic wall. We consider a successful caval‐aortic guidewire traversal to be a “commitment,” because abandoned traversals can cause pinhole aortic leaks. Absent a corresponding decompressing venous hole, such leaks can generate pseudoaneurysm or (unlike this case) even hemorrhage. Such leaks are usually evident on procedural aortography. The best solution is to recross the aorta and complete the transcaval TAVI within millimeters of the abandoned hole, so that the large aorto‐caval fistula encompasses the earlier abandoned spot, and the nitinol closure device facilitates thrombosis and closure. Following these simple procedure and troubleshooting steps, and “honoring our commitments” to transcaval aortic guidewire traversal, can help to prevent and manage complications.

Robert J. Lederman

Papers

Transcatheter Electrosurgery: A Narrative Review

MRI-guided drug and cell injection therapies for heart disease

Effect of Leaflet Laceration on TAVR Fluid Mechanics and Comparison with SAVR

Troubleshooting transcaval access: Honoring our commitments

Reply: Alternative Access Options for Transcatheter Aortic Valve Replacement.