Techniques in Vascular and Interventional Radiology

Hepatic artery complications can be divided into 2 different categories, nonocclusive and steno-occlusive disease. Steno-occlusive disease is a collective term that encompasses hepatic artery thrombosis, hepatic artery stenosis, and hepatic arterial kinks, while nonocclusive arterial disease encompasses less than 5% of complications and is a collective term used to describe arteriovenous fistulae, pseudoaneurysms, arterial rupture and nonocclusive hepatic artery hypoperfusion syndrome. This article details the angiographic techniques and definitions needed to accurately diagnose arterial transplant complications and describes the technical aspects and results of endoluminal management of these arterial complications...

Lung transplant remains an important treatment option for patients with end-stage lung diseases providing improvement in survival rates and quality of life. Specialized considerations should be applied with interventions of lung transplant recipients as they host specific anatomic variations and high risk towards certain complications. In this article, we highlight the role of interventional radiology for lung transplant recipients along with discussion of interventional techniques. Specific emphasis is placed on describing and explaining the techniques pertained to the points of anastomosis, diagnosis and treatment of malignancies, and management of complications in lung transplant recipients...

No abstract text is available yet for this article.

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disorder characterized by the destruction of insulin-secreting beta cells in the pancreas, resulting in metabolic disturbances and long-term complications. While subcutaneous insulin remains the primary approach for achieving normoglycemia, pancreatic transplantation has emerged as an effective intervention for long-standing T1DM, providing insulin independence and normalized glycosylated hemoglobin levels. However, complications associated with pancreatic transplantation are frequent, necessitating thorough evaluation using diverse imaging modalities...

The field of pediatric organ transplantation has grown significantly in recent decades, with interventional radiology (IR) playing an essential role in managing pre and post-transplant complications. Pediatric transplant patients face unique challenges compared to adults, including donor-recipient size mismatch, and complications of a growing child with changing physiology. Interventional radiologists play a major role in pediatric renal and liver transplant. IR interventions begin early in the child's pretransplant journey, with diagnostic procedures such as biopsies, angiograms, and cholangiograms...

Renal transplantation is the most commonly performed solid-organ allograft surgery; in 2021, 25487 kidneys were transplanted in the United States, and nearly 42,000 adult patients were listed for transplant. As the treatment of choice for patients with end-stage renal disease, transplantation is performed at more than 250 centers. Despite a high rate of success, renal transplantation is not without complication, and the interventional radiologist plays a crucial role in the management of the postoperative patient...

Orthotopic heart transplantation is a life-saving procedure that has substantially improved the lives of countless patients since its inception. However, there are several procedure-related complications that require prompt management. Interventional radiology, with its ever expanding toolkit, is a cornerstone of the multidisciplinary team following post-cardiac transplant patients. Percutaneous, endovascular therapy provides minimally invasive, safe, and effective treatments for immediate and delayed cardiac transplant complications and this paper serves to highlight the various management options interventional radiology can provide for orthotopic heart transplantation complications...

No abstract text is available yet for this article.

Liver transplantation is a technically demanding surgical procedure with known complications, and the optimal approach to addressing vascular and biliary complications requires a coordinated effort between surgical and interventional radiology teams. Vascular complications involving the hepatic artery, portal vein, or hepatic veins can be characterized by their mechanism, chronicity, and timing of presentation. These factors help determine whether the optimal therapeutic approach is surgical or endovascular...

Liver transplantation continues to rapidly evolve, and in 2020, 8906 orthotopic liver transplants were performed in the United States. As a technically complex surgery with multiple vascular anastomoses, stenosis and thrombosis of the venous anastomoses are among the recognized vascular complications. While rare, venous complications may be challenging to manage and can threaten the graft and the patient. In the last 20 years, endovascular approaches have been increasingly utilized to treat post-transplant venous complications...

CT navigation (CTN) has recently been developed to combine many of the advantages of conventional CT and CT-fluoroscopic guidance for needle placement. CTN systems display real-time needle position superimposed on a CT dataset. This is accomplished by placing electromagnetic (EM) or optical transmitters/sensors on the patient and needle, combined with fiducials placed within the scan field to superimpose a known needle location onto a CT dataset. Advantages of CTN include real-time needle tracking using a contemporaneous CT dataset with the patient in the treatment position, reduced radiation to the physician, facilitation of procedures outside the gantry plane, fewer helical scans during needle placement, and needle guidance based on diagnostic-quality CT datasets...

Virtual reality (VR) and augmented Reality (AR) are emerging technologies with the potential to revolutionize Interventional radiology (IR). These innovations offer advantages in patient care, interventional planning, and educational training by improving the visualization and navigation of medical images. Despite progress, several challenges hinder their widespread adoption, including limitations in navigation systems, cost, clinical acceptance, and technical constraints of AR/VR equipment. However, ongoing research holds promise with recent advancements such as shape-sensing needles and improved organ deformation modeling...

Endovascular robots have the potential to revolutionize the field of vascular interventions by enhancing procedural efficiency, accuracy, and standardization. They aim to reduce radiation exposure, as well as physical strain on operators and medical staff, while enabling precise navigation of catheters through challenging anatomical structures. However, the widespread adoption of these robots faces barriers, such as real estate constraints, setup time, limited range of compatible tools, and high costs. This paper discusses these barriers and highlights Hansen Medical's Magellan and the Liberty robotic systems as notable examples...

Advancements in minimally invasive technology, coupled with imaging breakthroughs, have empowered the field of interventional radiology to achieve unparalleled precision in image-guided diagnosis and treatment while simultaneously reducing periprocedural morbidity. Molecular imaging, which provides valuable physiological and metabolic information alongside anatomical localization, can expand the capabilities of image-guided interventions. Among various molecular imaging techniques, positron emission tomography (PET) stands out for its superior spatial resolution and ability to acquire quantitative data...

No abstract text is available yet for this article.

Contrast-enhanced ultrasound (CEUS) uses intravenously injected gas microbubbles as a pure blood pool contrast agent to demonstrate blood flow and tissue perfusion at a much higher sensitivity than color Doppler and power Doppler ultrasound. CEUS has gained traction in abdominal diagnostic imaging for improved lesion detection and characterization and a complementary problem-solving tool to CT and MRI. In addition to its diagnostic applications, CEUS has also proven useful for pre-procedure planning, procedure guidance, and post-procedure evaluation...

Image fusion technology aims to improve patient outcomes for image-guided interventions by leveraging the strengths of multimodality imaging datasets. This most commonly involves the overlay or co-display of advanced cross-sectional imaging permitting freedom of device placement via conventional image guidance such as ultrasound, fluoroscopy, and computed tomography. This can allow the interventionalist to target and treat lesions that would otherwise be difficult or impossible to visualize and access using conventional imaging guidance...

Cone-beam computed tomography (CBCT) has emerged as a prominent imaging modality in interventional radiology that offers real-time visualization and precise guidance in various procedures. This article aims to provide an overview of the techniques used to guide and monitor interventions that use CBCT. It discusses the advantages of CBCT, its current applications, and potential future CBCT-related developments in the field of interventional radiology.

The accuracy of the robotic device not only relies on a reproducible needle advancement, but also on the possibility to correct target movement at chosen checkpoints and to deviate from a linear to a nonlinear trajectory. We report our experience in using the robotic device for the insertion of trocar needles in CT guided procedures. The majority of procedures were targeted organ biopsies in the chest abdomen or pelvis. The accuracy of needle placement after target adjustments did not significantly differ from those patients where a linear trajectory could be used...

Magnetic resonance (MR) image guidance has demonstrated significant potential in the field of interventional radiology in several applications. This article covers the main points of MR-guided hepatic tumor ablation as a representative of MR-guided procedures. Patient selection and appropriate equipment utilization are essential for successful MR-guided tumor ablation. Intra-procedural planning imaging enables the visualization of the tumor and surrounding anatomical structures in most cases without the application of a contrast agent, ensuring optimal planning of the applicator tract...