New Developments in Image-Guided Percutaneous Irreversible Electroporation of Solid Tumors.

PURPOSE OF REVIEW: This review will describe the various applications, benefits, risks, and approaches of conventional irreversible electroporation (IRE), as well as highlight the new technological developments of this procedure along with their clinical applications. RECENT FINDINGS: Minimally invasive image-guided percutaneous IRE ablation has emerged as a newer, non-thermal ablation technique for tumors in the solid organs, particularly within the liver, pancreas, kidney, and prostate. IRE allows for ablation near heat-sensitive structures, including major blood vessels and nerves, and is not susceptible to the heat sink effect. However, it is limited by certain requirements, such as the need for precise parallel placement of at least two probes with a maximum inter-probe distance of 2.5 cm to reduce the risk of arching phenomenon, the requirement for general anesthesia with muscle relaxant, and the need for cardiac synchronization. However, new technological advancements in the ablation system and image guidance tools have been introduced to improve the efficiency and efficacy of IRE. IRE is a safe and effective treatment option for solid tumor ablation within the liver, pancreas, kidney, and prostate. Compared with other ablation techniques, IRE has several advantages, such as the absence of heat sink effect and minimal injury to blood vessels and bile ducts while activating the immune system. Novel techniques such as H-FIRE, needle placement systems, and robotics have enhanced the accuracy and performance in placement of IRE probes. IRE can be especially beneficial when combined with chemotherapy, immunomodulation, and immunotherapy.

Techniques Providing Endpoints for Revascularization in Chronic Limb-Threatening Ischemia.

It is frequently difficult to estimate the revascularization endpoint in patients with chronic limb-threatening ischemia where there may be extensive multifocal multiarterial disease. There have been attempts to identify an endpoint for revascularization procedures, but none has become the standard of care. An ideal indicator of an endpoint can objectively quantify tissue perfusion, predict wound healing, and is easily and efficiently used intraprocedurally to assist real-time decision making on whether adequate perfusion has been reached. Candidate techniques to evaluate endpoints post-revascularization are discussed here.

Technical Approach to Percutaneous Femoropopliteal Bypass and Deep Vein Arterialization.

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.

Interventional Radiology Workforce Shortages Affecting Small and Rural Practices: A Report of the SIR/ACR Joint Task Force on Recruitment and Retention of Interventional Radiologists to Small and Rural Practices.

Radiology practices characterized as small and rural are challenged to recruit and retain interventional radiologists. Lack of access to interventional radiologic services results in a failure to meet the needs of patients, hospitals, and other community stakeholders. Acknowledging this challenge, the ACR's Commission on General, Small, Emergency and/or Rural Practice and Commission on Interventional and Cardiovascular Imaging and the Society of Interventional Radiology partnered to establish a joint task force to study this issue and identify strategies the ACR and the Society of Interventional Radiology should take to improve small and rural practice recruitment and retention of interventional radiologists. This report describes the deliberations and recommendations of the task force.

Iliac Vein Stenosis: Is the Data Strong Enough for Stenting in the Young Pelvic Venous Disorders (PeVD) Population?

Iliac vein stenosis is a clinical condition resulting from external compression of the iliocaval venous unit with the consequent remodeling of the vascular wall, hemodynamic alterations, and predisposition to venous thrombosis. As such, the most common indications for percutaneous endovascular iliac vein stenting supported by the literature, include the management of thrombotic and non-thrombotic iliac venous lesions associated with advanced chronic venous disease (CVD). However, its clinical presentation is variable, and it may also include features associated with PeVD such as chronic pelvic pain, perineal heaviness, urinary urgency, postcoital pain, and vulvar or superficial non-saphenous veins varicosities. In this setting, the management revolves around the relieving venous obstruction and restoring normal blood flow through the compressed vein with percutaneous endovascular iliac vein stenting, that can be augmented with ovarian vein embolization (OVE) or direct embolization of the superficial varices. Given the heterogeneity of PeVD presentation and the lack of high-level quality data in outcomes for iliac vein stenosis stenting, this review will discuss the current evidence available for this intervention and clinical issues to consider when evaluating these patients.

Choosing the Most Appropriate Treatment Option for Pelvic Venous Disease: Stenting versus Embolization.

Pelvic venous disease (PeVD) in women encompasses a wide variety of entities all resulting in pelvic pain and varices. Successful treatment with percutaneous interventions is dependent on identifying underlying factors contributing to the disease and addressing them with either embolization of incompetent veins or stenting for venous stenoses. There are a multitude of embolization methods with marked practice heterogeneity. Moreover, with the ongoing development of dedicated venous stents in the treatment of chronic venous disease, there are more opportunities to consider this modality for the treatment of PeVD, as many patients present with combined vein reflux and central venous stenosis. The necessity to address both and the order of interventions in these patients is still to be elucidated. Here, we describe when to choose stenting or embolization for PeVD, their limitations, and our practice and identify further areas of research in this field.