Marco Cura

Diagnostic and interventional radiology for Budd-Chiari syndrome

Budd-Chiari syndrome is a heterogeneous group of disorders characterized by hepatic venous outflow obstruction that involves one or more draining hepatic veins. Its occurrence in populations in the western hemisphere is commonly associated with hypercoagulative states. Clinical manifestations in many cases are nonspecific, and imaging may be critical for early diagnosis of venous obstruction and accurate assessment of the extent of disease. If Budd-Chiari syndrome is not treated promptly and appropriately, the outcome may be dismal. Comprehensive imaging evaluations, in combination with pathologic analyses and clinical testing, are essential for determining the severity of disease, stratifying risk, selecting the appropriate therapy, and objectively assessing the response. The main goal of treatment is to alleviate hepatic congestion, thereby improving hepatocyte function and allowing resolution of portal hypertension. Various medical, endovascular, and surgical treatment options are available. Percutaneous and endovascular procedures, when performed in properly selected patients, may be more effective than medical treatment methods for preserving liver function and arresting disease progression in the long term. In addition, such procedures are associated with lower morbidity and mortality than are open surgical techniques.

Causes of TIPS Dysfunction

OBJECTIVE Transjugular intrahepatic portosystemic shunt (TIPS) creation is an effective method to control portal hypertension. TIPS creations with bare stents have shown limited and unpredictable patency. In nearly all cases of rebleeding or recurrent ascites after TIPS creation, there is shunt stenosis or occlusion. The purpose of this article is to review the biologic and technical factors that predispose to TIPS failure and how the use of an expandable polytetrafluoroethylene (PTFE)-covered-stent has significantly improved TIPS patency. CONCLUSION Biologic and technical factors may predispose to shunt failure. The combination of improved technique and expandable PTFE has significantly improved TIPS patency. The need for follow-up venography and secondary interventions has been reduced significantly as a result of improved shunt patency.

Vascular malformations and arteriovenous fistulas of the kidney

Vascular malformations of the kidney are disease processes that involve renal veins and arteries and include congenital arteriovenous malformations (AVMs) and arteriovenous fistulas. AVMs are congenital communications between arteries and veins with a vascular nidus that bypass the capillary bed. Congenital AVMs are rare and subclassified in cirsoid, angiomatous, and aneurysmal types. Congenital AVMs are different from iatrogenic or traumatic arteriovenous fistulas (AVF), which are characterized by a single direct communication between an artery and a vein without an intervening vascular nidus. These lesions may present with a wide range of signs and symptoms that vary from hypertension to renal masses. Imaging is valuable in the detection and characterization of AVM and AVF. The presence of arteriovenous shunting characterizes AVM and AVF. These lesions represent an important group of entities for diagnostic consideration, and understanding the vascular anatomy helps in guiding for proper treatment. This article describes the imaging features of each lesion that help to differentiate it from the others and the endovascular therapies to treat these vascular processes and their possible complications.

Arteriovenous Malformations of the Uterus

Arterial venous malformations (AVM) of the uterus are uncommon entities and should be considered in patients who present with profuse genital bleeding. There are two types of uterine AVM: acquired and congenital. Acquired uterine AVMs are conformed by communications between the uterine arteries and the myometrial veins, and are caused by an iatrogenic event or a pathological condition. Congenital AVMs are the result of abnormal development of primitive vessels that result in connections between pelvic arteries and veins in the uterus without an interconnecting capillary bed. Ultrasonography is a noninvasive diagnostic method able to demonstrate and characterize AVMs of the uterus. AVM in the pelvis may be noted incidentally by computed tomography (CT) of the pelvis, and magnetic resonance imaging (MRI) is frequently used to confirm and further characterize the sonographic findings of uterine AVM. Catheter angiography and embolization are very effective in defining the vascular anatomy and treating uterine vascular abnormalities.

Role of magnetic resonance imaging in patient selection for uterine artery embolization.

Uterine fibroids are common tumors of the female pelvis. Uterine artery embolization (UAE) is an effective treatment of symptomatic uterine leiomyoma in the appropriate candidates, reducing or eliminating leiomyoma-related symptoms of bleeding, bulk, and/or pain. Magnetic resonance imaging (MRI) can be used to assess women with symptoms potentially attributable to uterine leiomyomas, and help to determine who is an appropriate candidate for UAE. Because of soft tissue characterization, multiplanar imaging capabilities, and enhancement, MR imaging not only accurately detects and characterizes uterine leiomyomas but also may predict who will benefit from the embolization. MRI ability to detect coexistent uterine or pelvic pathology may change the diagnosis and treatment management of patients being evaluated for UAE.

Renal aneurysms and pseudoaneurysms.

Pseudoaneurysms and aneurysms are abnormal dilatations of the vessel lumen. Pseudoaneurysm is a perfused hematoma contained by the adventitia and perivascular tissues that is in communication with the lumen of an adjacent artery or vein. Aneurysm is a dilatation of the vessel lumen involving all three layers of the blood vessel wall. Renal artery aneurysms (RAA) are uncommon but the widespread use of cross-sectional imaging and incidental detection of RAA may result in an increasing number of cases diagnosed. Renal artery pseudoaneurysms are suspected in bleeding patients after penetrating renal trauma. Imaging plays a major role in the detection of renal pseudoaneurysms and aneurysms and diagnoses aneurysm rupture and active bleeding. Computed tomography (CT), magnetic resonance imaging, and digital subtraction angiography can characterize lesion size, shape, and location and identify other aneurysms and pseudoaneurysms, helping to narrow the differential diagnosis and to understand the vascular anatomy for guiding proper treatment. Endovascular treatments have contributed considerably in the management of renal pseudoaneurysms and aneurysms. The use of coil embolization or covered stent placement prevents the mortality and mobility of surgery. The article describes imaging features and the endovascular therapies to treat these vascular processes and their possible complications.

Transjugular Intrahepatic Portosystemic Shunt Flow Reduction with Adjustable Polytetrafluoroethylene-covered Balloon-expandable Stents

Creation of a transjugular intrahepatic portosystemic shunt (TIPS) can effectively treat complications of portal hypertension, but excessive shunting can cause life-threatening hepatic encephalopathy and hepatic insufficiency. The present report describes a novel technique that allows for controlled and adjustable flow reduction through the TIPS via partial closure of the shunt with a balloon-mounted covered stent. The method results in clinical improvement of hepatic encephalopathy and hepatic insufficiency and immediate increase in the portosystemic pressure gradient. However, among the four patients described herein, survival beyond 1 year was seen in only one, who underwent liver transplantation after TIPS reduction.

Peripheral vascular tumors and vascular malformations: imaging (magnetic resonance imaging and conventional angiography), pathologic correlation and treatment options

Vascular anomalies are classified into vascular tumors (infantile hemangioma) and vascular malformations. Vascular malformations are divided into slow flow and high flow subtypes. Magnetic resonance imaging helps in classification and assessing extent and distribution. Conventional angiography also known as digital subtraction angiography is pivotal in assessment of fine vascular details and treatment planning. Imaging correlates well with histopathology. We review recent development in imaging techniques of various vascular anomalies most of which are affecting the peripheral system which potentially may broaden understanding of their diagnosis, classification and treatment.

Transjugular Intrahepatic Portosystemic Shunt for Variceal Hemorrhage due to Recurrent of Hereditary Hemorrhagic Telangiectasia in a Liver Transplant

Hepatic involvement in hereditary hemorrhagic telangiectasia (HHT) consists of vascular malformations associated with arteriovenous (AV), arterioportal, and/or portovenous shunting. Most patients with HHT have liver involvement. Symptoms, although rare, consist of cardiac failure, pulmonary hypertension, portal hypertension, portosystemic encephalopathy, cholangitis, and atypical cirrhosis. Reported treatments for symptomatic AV malformations have been associated with substantial morbidity and mortality. This report describes a case of hepatic HHT that required liver transplantation after hepatic artery embolization. Recurrent vascular malformations developed in the transplant, resulting in portal hypertension and life-threatening variceal hemorrhage that was controlled with transjugular intrahepatic portosystemic shunt creation.

MDCT angiography of mesenteric bypass surgery for the treatment of chronic mesenteric ischemia

OBJECTIVE Chronic mesenteric ischemia (CMI) is a serious condition that requires surgical or endovascular intervention. Surgical revascularization for the treatment of CMI uses different operative techniques including endarterectomy, vessel reimplantation, and mesenteric bypass. A basic understanding of the operative techniques is essential for the adequate interpretation of imaging studies in patients who have undergone surgery for CMI. In this article, we review the different operative techniques used in the treatment of CMI, discuss the results of surgical intervention for CMI, and illustrate how MDCT angiography (MDCTA) can be used for follow-up and for the detection of early and late complications after surgery. CONCLUSION MDCTA is a powerful tool for the postoperative evaluation of patients with CMI. Early detection of graft dysfunction is critical to prevent graft occlusion and the development of potentially fatal mesenteric ischemia. MDCTA can detect early and late complications after surgery and guide additional surgical or endovascular interventions.