Murthy R. Chamarthy

Complications of inferior vena cava filters

Inferior vena cava (IVC) filter placement is a relatively low risk alternative for prophylaxis against pulmonary embolism in patients with pelvic or lower extremity deep venous thrombosis who are not suitable for anticoagulation. There is an increasing trend in the number of IVC filter implantation procedures performed every year. There are many device types in the market and in the early 2000s, the introduction of retrievable filters brought an additional subset of complications to consider. Modern filter designs have led to decreased morbidity and mortality, however, a thorough understanding of the limitations and complications of IVC filters is necessary to weight the risks and benefits of placing IVC filters. In this review, the complications associated with IVC filters are divided into procedure related, post-procedure, and retrieval complications. Differences amongst the device types and retrievable filters are described, though this is limited by a significant lack of prospective studies. Additionally, the clinical presentation as well as prevention and treatment strategies are outlined with each complication type.

Thrombolysis and Transjugular Intrahepatic Portosystemic Shunt Creation for Acute and Subacute Portal Vein Thrombosis

Catheter-based interventional therapy offers a safe and effective option for treatment of symptomatic portomesenteric venous thrombosis refractory to medical therapy. Various techniques and approaches have been described for thrombolysis and thrombectomy and re-establishing the portal venous flow for select populations. Early diagnosis and prompt treatment based on clinical presentation, imaging, and underlying anatomy are necessary to prevent long-term complications. This article describes various catheter-based approaches for treatment of acute and subacute portal vein thrombosis.

Interventional radiology in the management of thoracic duct injuries: Anatomy, techniques and results

Disruption of the thoracic duct can have devastating consequences and be associated with a high morbidity and mortality. Conservative therapies have been attempted to treat chylothorax without much success. Surgical management has traditionally been necessary to provide definitive treatment at the expense of increased morbidity. Lymphatic interventions have recently emerged as a new frontier for interventional radiologists to add value and provide minimally invasive therapies for debilitating conditions. The goal of this manuscript is to review the anatomy of the thoracic duct, describe various percutaneous techniques for accessing the duct, and briefly discuss outcomes as reported in the literature.

Diagnosis and interventions of vascular complications in lung transplant

Though rare, pulmonary vascular complications after lung transplantation carry high morbidity and mortality. Knowledge of the normal and abnormal appearance of lung transplant vasculature is essential for timely and appropriate diagnosis and management of complications. Appropriate selection of surgical and endovascular treatments depend on the availability of expertise and requires a multidisciplinary approach to ensure the best outcomes.

Pulmonary vascular anatomy & anatomical variants

The vessels supplying the lungs include the pulmonary arteries, pulmonary veins, and bronchial arteries. The segmental and sub segmental pulmonary arteries parallel the bronchi and are named according to the bronchopulmonary segments they supply. There are however considerable anatomic variations, particularly in the upper lobes with variations in number or presence of accessory arteries from adjacent segments. The subsegmental pulmonary vein branches, run within interlobular septa and do not parallel the segmental or sub segmental pulmonary artery branches and bronchi. They converge to form right and left superior and inferior pulmonary veins which drain into the left atrium. Knowledge of normal and variant anatomy on cross-sectional and angiographic images is essential for accurate diagnosis of vascular pathology and aids planning of interventional procedures.

Pulmonary vasculitis: Diagnosis and endovascular therapy

Pulmonary vasculitides are caused by a heterogeneous group of diseases with different clinical features and etiologies. Radiologic manifestations depend on the predominant type of vessel involved, which are grouped into large, medium, or small-sized vessels. Diagnosing pulmonary vasculitides is a challenging task, and radiologists play an important role in their management by providing supportive evidence for diagnosis and opportunities for minimally invasive therapy. This paper aims to present a practical approach for understanding the vasculitides that can affect the pulmonary vessels and lungs. We will describe and illustrate the main radiologic findings, discussing opportunities for minimally invasive treatment.

Pulmonary artery aneurysms: diagnosis & endovascular therapy

Pulmonary artery aneurysms (PAAs) and pseudoaneurysms are rare entities in the spectrum of pulmonary arterial diseases. The etiology of these aneurysms is varied and patients present with nonspecific symptoms which make their diagnosis both difficult and less often considered. In this review, we will discuss the clinical manifestations, etiologies, methods of detection, imaging features, and the current role of endovascular treatment in the management of PAAs.

Pulmonary arteriovenous malformations: diagnosis

Pulmonary arteriovenous malformations (PAVMs) are rare, abnormal low resistance vascular structures that connect a pulmonary artery to a pulmonary vein, thereby bypassing the normal pulmonary capillary bed and resulting in an intrapulmonary right-to-left shunt. The spectrum of PAVMs extends from microscopic lesions causing profound hypoxemia and ground glass appearance on computed tomography (CT) but with normal catheter angiographic findings to classic pulmonary aneurysmal connections that abnormally connect pulmonary veins and arteries. These malformations most commonly are seen in hereditary hemorrhagic telangiectasia (HHT). They are rarely due to secondary conditions such as post congenital heart disease surgery or hepatopulmonary syndrome (HPS). The main complications of PAVM result from intrapulmonary shunt and include stroke, brain abscess, and hypoxemia. Local pulmonary complications include PAVM rupture leading to life-threatening hemoptysis or hemothorax. The preferred screening test for PAVM is transthoracic contrast echocardiography (TTCE). CT has become the gold standard imaging test to establish the presence of PAVM. Endovascular occlusion of the feeding artery is the treatment of choice. Collateralization and recanalization of PAVM following treatment may occur, and hence long term clinical and imaging follow-up is required to assess PAVM enlargement and PAVM reperfusion.

Pulmonary arteriovenous malformations: endovascular therapy

Pulmonary arteriovenous malformations (PAVM) are abnormal direct communications between the branches of pulmonary arteries and veins, and are often seen in patients with hereditary hemorrhagic telangiectasia (HHT). If untreated, the right to left shunt can result in symptoms of hypoxemia, paradoxical emboli to the left side circulation, stroke and intracranial abscess. Endovascular therapy is a minimally invasive outpatient based treatment wherein the feeding artery to the PAVM is occluded with coils or plugs or a combination of both and is associated with minimal morbidity and no mortality. In this manuscript, we will review the indications and contraindications for endovascular therapy, pre-procedural work up, procedure technique and variations, complications, and outcomes.

Pulmonary vascular pathophysiology

Knowledge of pulmonary vascular pathophysiology is crucial to understand the various disease processes and their medical management. Pulmonary vascular system constitutes the right sided circulation which is distinct from the left side circulation and facilitates unique hemodynamic properties to adapt to a multitude of external demands and circumstances. With growing prevalence and increasing ability to diagnose and treat pulmonary diseases, this review becomes more relevant.