Shellie C. Josephs

Percutaneous radiofrequency ablation of renal tumors: technique, limitations, and morbidity

OBJECTIVES To evaluate our evolving experience with percutaneous radiofrequency (RF) renal tumor ablation and focus on our technique to ensure maximal treatment efficacy and reduce the possibility of complications. METHODS Fifteen patients with small (less than 4 cm) posterior or lateral contrast-enhancing (more than 10 Hounsfield units) renal tumors were candidates for RF treatment. Of these patients, 12 (13 tumors) received computed tomography-guided percutaneous RF ablation. General anesthesia was administered in all but our first 2 patients, who received intravenous sedation. After treatment, patients were closely followed up with computed tomography scans at 6 weeks and 3, 6, and 12 months, and every 6 months thereafter. Successful ablation was defined as a lesion along with a margin of normal parenchyma that no longer enhanced (less than 10 Hounsfield units) on follow-up contrast imaging. RESULTS The mean tumor size was 2.4 +/- 0.6 cm. The average procedure time was 95 minutes (range 60 to 150) and length of stay 0.9 days. All patients underwent the procedure without any major complications. At a mean follow-up of 4.9 months, 12 (93%) of 13 tumors were successfully ablated. In 3 patients, the procedure was not performed because of intervening bowel or lung parenchyma when positioned in the prone position before the procedure. Computed tomography-guided percutaneous RF ablation of small renal tumors is a viable minimally invasive treatment option with a high short-term success rate and low morbidity. This new technology must be uniformly applied to assess its long-term efficacy.

Rapid cortisol assays improve the success rate of adrenal vein sampling for primary aldosteronism.

Objective:We hypothesized that an adrenal vein sampling (AVS) algorithm incorporating rapid cortisol assays, which enables resampling of the adrenal veins, would improve the success rate by a team of radiologists. Summary Background Data:AVS is the most accurate means to localize aldosterone production in primary aldosteronism (PA). However, cannulation of the right adrenal vein (RAV) is difficult, and success is assumed from venography without the support of steroid assays. Furthermore, few institutions can assign all studies to 1 dedicated and experienced AVS interventional radiologist. Methods:Retrospective chart review of patients with PA at our university hospitals who underwent AVS. We compared results for 30 AVS studies incorporating rapid cortisol assays with 30 conventional AVS studies. Results:The success rate for the control period was 73% (22/30 studies). For the first 30 studies after incorporating rapid cortisol assay, the success rate increased to 97% (29/30 studies). Resampling the RAV was required for 2 studies, and prolonged sheath insertion did not cause any complications. Conclusions:High AVS success rates may be achieved by a team of interventional radiologists at 1 center using defined AVS protocols. Rapid cortisol assay allows for resampling of the RAV and improves AVS success rates.

Common and rare collateral pathways in aortoiliac occlusive disease: A pictorial essay

OBJECTIVE The development of collateral pathways for arterial blood flow is common in the presence of atherosclerotic occlusive disease of the abdominal aorta and iliac arteries. The collateral pathways are divided into systemic-systemic and systemic-visceral pathways. MDCT is commonly used to evaluate aortic stenosis and the resulting collateral pathways. CONCLUSION Common and rare arterial collateral pathways are reviewed by 3D volume-rendered CT images. Visceral and lower extremity arterial embryology is reviewed.

Atherosclerotic Peripheral Vascular Disease Symposium II: Executive Summary

The Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group was commissioned by the American Heart Association (AHA) to provide a forum to address important and emerging issues in this multidisciplinary area of clinical science. The working group was a primary outgrowth of the AHA Atherosclerotic Vascular Disease Conference held in Boston, Mass, in July 2002. It was created in recognition of the fact that atherosclerosis is a systemic disease with important sequelae in many regional circulations in addition to the heart, including the brain, kidneys, mesentery, and limbs. Its mission is to provide a forum for the multiple disciplines engaged in research, evaluation, and management of patients with noncoronary atherosclerosis. The goals of the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group are to develop a strategy to increase awareness of atherosclerotic vascular disease, identify important gap areas in knowledge that require further clinical investigation, and develop programs that will facilitate prevention and treatment of peripheral atherosclerotic diseases. Developments in research and technology that are relevant to atherosclerotic vascular disease are emerging rapidly. As a result, greater opportunities to translate science to clinical practice are available. The American College of Cardiology/AHA practice guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic) provide many evidenced-based recommendations for diagnosing and treating patients with atherosclerotic vascular diseases.1 Nevertheless, in some areas, the evidence has not matured sufficiently for definitive guidelines. Some of these areas have engendered considerable controversy among practitioners. Among these are the efficacy and outcome of screening programs for vascular disease and the appropriate and timely use of endovascular interventions. Accordingly, the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group convened the second AHA conference on Atherosclerotic Vascular Disease, which took place in Boston, Mass, in July 2006. The conference was also sponsored by the …

Obstetric and Gynecologic Emergencies: A Review of Indications and Interventional Techniques

There are many interventional techniques that can be used to aid the obstetrician or gynecologist in caring for their patients in the acute setting. Embolization can be life saving in the case of postpartum hemorrhage. Bleeding related to cervical cancer or the threat of bleeding from cervical ectopic pregnancy is amenable to embolization as is hemorrhage related to uterine arteriovenous malformations. Postpartum women are also at a uniquely high risk for deep vein thrombosis and pulmonary emboli and may benefit from consultation and treatment by an interventional radiologist. The goal of this article is to discuss the valuable role that the interventional radiologist plays in the treatment of these obstetric and gynecologic conditions.

Improving the tracking and removal of retrievable inferior vena cava filters

Therapeutic and prophylactic inferior vena cava (IVC) filters should be placed based on currently accepted indications to prevent a fatal pulmonary embolism (PE). The protective effect of filters is offset by the potential for lower extremity deep venous thrombosis (DVT), caval thrombosis, and possible otherwise unnecessary life-long anticoagulation (AC). The duration of treatment for most DVTs or PEs is 3 to 6 months of AC/filter. Filters should be retrieved when duration of treatment for a DVT/PE has been met, the risk of a PE is no longer high, and/or there is no longer a contraindication to AC. An effective system that leads to improving the retrieval rate of filters must include education of the patient, a tracking system to minimize patient lost to follow-up, and dedicated personnel to oversee the process. If these goals are accomplished, interventionalists can help decrease the incidence of a fatal PE during the high-risk period, and also decrease the risk of a DVT or the use of otherwise unnecessary life-long AC in subsequent years. Currently, there is much room for improvement in the frequency that IVCF patients are systematically followed and filters are retrieved. The principles discussed in this report will be helpful in this process.

Atherosclerotic Peripheral Vascular Disease Symposium II Vascular Magnetic Resonance and Computed Tomographic Imaging

Over the past 10 years, there has been a rapid adoption of new technology that has allowed us to image the vascular system in a noninvasive manner with greater speed and improved resolution. The “gold standard,” catheter-based angiography, is now more often used with therapeutic interventions rather than purely diagnostic studies. Catheter-based angiography is being replaced by computerized tomographic angiography (CTA) and magnetic resonance angiography (MRA) for carotid, renal, and peripheral vascular diagnostic examinations. The goal of this writing group is to review the evidence-based approach to selection of imaging modalities; however, regional availability and expertise are recognized as important factors in the selection of imaging modalities.

Polytetrafluoroethylene-encapsulated Stent-Grafts: Use in Experimental Abdominal Aortic Aneurysm

PURPOSE To evaluate expanded polytetrafluoroethylene (ePTFE) encapsulated stents for the treatment of aortic aneurysms with emphasis on the blood and tissue-material interactions. MATERIALS AND METHODS Experimental aortic aneurysms were created in dogs by enlarging the aortic lumen with an abdominal fascial patch. Twenty animals underwent endoluminal repair after allowing the surgically created aneurysm to heal for 2 months prior to transluminal aneurysmal exclusion. The device used consisted of an 8-cm-long ePTFE encapsulated stent graft. The animals were killed in groups at 1 week and at 1, 2.25, 6, and 12 months. Specimens were processed for histologic and luminal surface studies. RESULTS Before the animals were killed, aortography demonstrated two thrombosed aortae in the 6-month group and two endoleaks in the 12-month group. Endothelialized neointima extended into the proximal and distal portions of the prosthetic lumen, with minimal cell coverage in the center of the graft. The overall percent surface area covered by endothelialized neointima was 22% +/- 6% at 6 months and 18% +/- 10% by 1 year (P = .75). Histologic examination demonstrated minimal tissue penetration into the ePTFE. CONCLUSION Transluminal exclusion of abdominal aortic aneurysms by encapsulated stent-graft is easily accomplished. With this device, tissue coverage and penetration of the stent graft is limited and does not tend to increase with time.

Pediatric Biliary Interventions

An interventional radiologist is frequently called to evaluate and treat biliary diseases in children; a tailored approach specific to this population is required. Imaging with an emphasis on minimizing ionizing radiation is used not only in the initial workup but also to guide interventions. The most common form of intervention generally consists of transhepatic biliary drainage to treat either biliary obstruction or bile leakage, a scenario frequently encountered after pediatric liver transplantation. Other pathologies referred for evaluation and management include biliary atresia and, rarely, symptomatic choledochal cysts. Biliary complications caused by an underlying malignancy are not a frequently encountered problem in the pediatric population. The initial evaluation, role of preprocedural imaging, and interventional management with an emphasis on technique are discussed regarding these common biliary pathologies in children.

Neoaortoiliac Reconstructions Using Femoropopliteal Veins: MDCT Angiography Findings

OBJECTIVE In this article, we discuss the neoaortoiliac system procedure, a surgical procedure that uses femoropopliteal vein segments for arterial reconstructions in patients with aortofemoral prosthetic graft infections. CONCLUSION CT angiography (CTA) is a powerful imaging tool that can be used in the follow-up of patients after this complex surgery. CTA accurately detects early and late complications that may develop after the neoaortoiliac system procedure.