Techniques in Vascular and Interventional Radiology最新文献

The vascular lab is an essential tool in diagnosing intracranial and extracranial disease including vasospasm from subarachnoid hemorrhage and carotid artery stenosis in the setting of stroke or transient ischemic attack. This article discusses the indications, protocol, and diagnostic criteria for transcranial doppler (TCD) and carotid artery duplex ultrasound. Intracranial and extracranial arterial testing by way of TCD and carotid imaging carries enormous implications and can provide life or death information. The learning curve for these techniques is steep but can be mastered with repetition and precise technique.

The vascular lab (VL) provides vital information for dialysis access to guide management. This article discusses the indication, protocol, and diagnostic criteria for the evaluation of arteriovenous fistulas and grafts. An arteriovenous (AV) dialysis access is made by creating a connection between an artery and vein (AV fistula [AVF]) or by interposing a conduit between an artery and a vein (AV graft [AVG]) to provide high flow circuit for hemodialysis. A normal mature AV dialysis access has a thrill or vibration from turbulent flow in the graft or vein. The nomenclatures at our institution for an AVF and AVG are in the Figure 1 A and B diagrams.

Setting up a vascular lab (VL) requires initial substantial capital, personnel, real-estate, and time commitment and requires support from leadership and champions. There are certain tangible building blocks for a successful VL. The more time and effort that are leant to these foundational components, the better the VL will operate. This article will discuss the preliminary measures that need to be in place for a successful VL. This article describes space, equipment, policy and procedure, structured reporting, and personnel – the tangible building blocks for a successful VL that needs advanced planning and implementation.

Patient evaluation is critical to identify and quantitate patient's disease. Aside from the patient's history and physical examination, imaging can help confirm and determine the extent of disease. Imaging can aid in treatment planning once the decision to proceed to intervention has been made. This chapter will discuss the role of imaging before and after peripheral arterial interventions and how it may improve intervention outcomes. It will discuss the value of the arterial noninvasive examinations (ankle-brachial index, toe-brachial index, pulse volume recordings, and arterial duplex ultrasound), computed tomographic angiograms, magnetic resonance angiogram, and intravascular ultrasound.

Peripheral arterial disease (PAD) is a common condition, which significantly impacts the quality and length of life. In recent years, drug-eluting devices have demonstrated improved clinical effectiveness for treating peripheral arterial disease in the femoropopliteal arteries compared to traditional stents and angioplasty balloons. However, recent controversial studies have called the safety of this technology into question, leading to confusion as to if, when, and how these devices should be used. This article focuses on the underlying pathophysiology and pharmacology, the clinical benefits and potential harms, as well as expected future developments affecting the use of these drug-eluting technologies in treating peripheral arterial disease of the superficial femoral arteries.

Peripheral artery disease (PAD) is a progressive vascular disease affecting millions of individuals and is a considerable cause of morbidity and mortality worldwide. While balloon angioplasty remains the cornerstone option for endovascular management of arterial stenosis, advances in percutaneous endovascular stent technology have broadened the toolbox of therapeutic options for PAD and have significantly improved function and quality of life. Indeed, covered stents, bioabsorbable stents and drug eluting stents are several of the innovations in stent technology made since the advent of nitinol bare metal stents in the 1980s. The indications for use, technical considerations, treatment outcomes, and current concerns regarding current stent devices will herein be discussed in this review.

Chronic total occlusions are a common cause of both claudication and critical limb ischemia. Currently, 40%-50% of all individuals undergoing lower extremity interventions will have a chronic total occlusion. Endovascular specialist should be familiar with the different treatment algorithms and classifications systems. Many different techniques have been shown to be successful in crossing the lesion and for re-entry when needed. The vascular access obtained to cross the lesion is frequently dictated by lesion location, lesion length, and the distal runoff in the affected limb.

In the management of patients with critical limb ischemia endovascular revascularization plays a crucial role improving amputation-free survival, ischemic rest pain, and wound healing. Endovascular standard of care of peripheral arterial occlusive disease involves angioplasty and/or stent placement. The following discussion is intended to familiarize interventional physicians with the rationale, physiological concepts, and technical approach to developing endovascular procedures—percutaneous femoropopliteal bypass and percutaneous deep vein arterialization. Percutaneous arterial bypass procedure is designed to treat long complex Trans-Atlantic Inter-Society Consensus C and D hemodynamically significant superficial femoral artery lesions by redirecting the flow of blood from the diseased arterial segment through a femoral vein conduit. Percutaneous deep vein arterialization is used for selected “no-option” critical limb ischemia patients who cannot undergo or have failed conventional endovascular and/or surgical revascularization due to extensive occlusion of the outflow arteries. It involves creation of an arteriovenous fistula between a tibial artery and a tibial vein, disruption of venous valves, and elimination of venous collaterals. The consequent arterialization of the distal venous bed enables delivery of oxygenated pressurized arterial blood to the ischemic tissues, stimulating angiogenesis and increasing flow in the existent collateral vessels, which in turn will improve limb salvage and amputation free survival.

The field of Interventional Radiology is said to have begun in 1964, when Dotter successfully restored circulation to an 82-year-old woman's leg with critical limb ischemia and gangrene by percutaneously dilating a localized stenosis of the superficial femoral artery using a Teflon catheter. The dilation catheter was revolutionary in the inception of angioplasty, and progress evolved with the development of angioplasty balloons. As angioplasty became more widely utilized, the focus turned to improving its results. Several factors are important to consider with regards to maximizing angioplasty results in peripheral interventions. These factors include vessel size, lesion length, lesion location, and the anatomic vascular bed. Operators must make thoughtful decisions regarding balloon choice, diameter, length, inflation pressures, inflation time, and employ these devices with excellent technique to optimize outcomes. Complications from angioplasty include elastic recoil, vessel dissection, vessel rupture, distal embolization, and neointimal hyperplasia. The most widely recognized limitation of angioplasty is the longevity of treatment effect. In order to improve long-term outcomes, different specialty balloons have been developed to address lesions resistant to plain balloon angioplasty and combat neointimal hyperplasia to improve outcomes. Ultimately the goal is to maximize vessel patency for the longest duration possible, and many exciting new technologies are on the horizon.

Arterial calcification (AC) is a common complication among patients with peripheral arterial disease (PAD). AC presents various challenges to PAD treatment including an increased likelihood of vessel rupture and dissection, and by acting as a physical barrier to drug delivery by angioplasty balloons. Intravascular lithotripsy (IVL) is a novel intervention that specifically targets AC by emitting sonic pressure waves that introduce microfractures in target calcified lesions to increase arterial compliance. Preliminary data has demonstrated the safety and efficacy of IVL in PAD treatment. The present article provides a technical overview of S-IVL, as well as a case series of the treatment of AC in common iliac, common femoral, superficial femoral, aortoiliac, and peroneal arterial lesions. Each case resulted in marked improvement of luminal patency, exhibiting the efficacy IVL.