Idiopathic subglottic stenosis in a young female patient.

A previously healthy 30-year-old woman presented with 3 years of progressive shortness of breath and audible wheezing. One year prior to presentation, she developed a chronic non-productive cough. Pulmonary function testing revealed flattened inspiratory and expiratory peaks, characteristic of an extrathoracic fixed tracheal obstruction. Bronchoscopy confirmed subglottic stenosis (SGS). She had no history of intubation, tracheostomy or evidence of a systemic inflammatory illness. She was diagnosed with idiopathic SGS and referred for rigid bronchoscopy with balloon dilatation resulting in improvement in her symptoms.

Congenital portosystemic shunt occlusion with an Amplatzer PFO occlusion device: a case report.

BACKGROUND: Congenital portosystemic shunts are embryological malformations in which portal venous flow is diverted to the systemic circulation. High morbidity and mortality are seen in patients with concurrent hepatic encephalopathy, hepatopulmonary syndrome, and pulmonary hypertension. Endovascular therapy, in the correct patient population, offers a less invasive method of treatment with rapid relief of symptoms. CASE PRESENTATION: In this report, we discuss the treatment of a two-year-old male with abnormal chorea-like movements, altered mental status, anisocoria and hyperammonemia diagnosed with an intrahepatic congenital portosystemic shunt between the inferior vena cava and right portal vein. Given the patient's amenable anatomy and shunt type, embolization was performed with an 18 mm Amplatzer patent foramen ovale occlusion device. CONCLUSIONS: Portosystemic shunts are a rare congenital abnormality without universal treatment guidelines. An Amplatzer PFO occlusion device can provide a novel method of shunt closure given appropriate shunt type, size and anatomy.

Imaging and Interventional Radiology for Cancer Management.

The past decade has brought about dramatic changes in the diagnosis and management of cancer. Advancements in imaging and minimally invasive interventional techniques combine to rapidly diagnose, stage, and in certain cases, treat various forms of cancer. Physicians treating patients with cancer are confronted with many challenges beginning with the initial diagnosis. Imaging plays an integral role in every step of caring for the patient with cancer. Advances in imaging allow the earlier detection and staging of the disease and aid in decision making and treatment planning.

Critical limb ischemia: an update for interventional radiologists.

Critical limb ischemia (CLI) is a growing epidemic with bleak patient outcomes. A variety of treatment modalities have been adopted to address CLI based on comorbidities, life expectancy, and the nature of the arterial disease. With advances in technology and treatment strategies, the clinical outcomes of CLI patients have significantly improved over recent years. However, despite progress, patency rates of both surgical and endovascular interventions, limb-salvage and amputation rates are still dismal. We review the epidemiology, treatment strategies, imaging modalities, and the microcirculation aspect of CLI.

Biliary tract interventions.

Biliary tract interventions remain a tremendous technical challenge to the interventionalist and require appropriate clinical postprocedural management. The increased use of endoscopy for biliary tract evaluation and intervention has served to largely replace percutaneous techniques, resulting in a decreased number of patients requiring primary percutaneous transhepatic biliary interventions. However, those patients who do present for percutaneous biliary procedures often represent a more technically difficult subset. Thorough familiarity with normal and variant biliary tract anatomy, and experience with a variety of techniques, will allow for successful biliary tract interventions in complex situations. This article reviews the current role of percutaneous transhepatic interventions in the emergency evaluation and management of biliary tract disease.

Radiographic reduction of intussusception in patients with cystic fibrosis.

Cystic fibrosis (CF) is a genetic disorder affecting approximately one in 2,500 births in the United States. Nearly 1% of patients with CF will develop intussusception, which is commonly ileocecal and felt to be secondary to inspissated feces. These patients generally present before the age of ten. Once the diagnosis of intussusception is confirmed on ultrasound or CT, surgery has been the mainstay of treatment in this patient group. We propose the use of air and contrast enemas as effective and beneficial non-operative approach in these patients. Clinical and imaging findings in four children with known CF who presented with intestinal intussusception, average age 13.25 +/- 5.3 years (range 8-18 years) were reviewed. Patients were diagnosed using ultrasound (n = 3) or abdominal CT (n = 1). All patients suffered from an ileocolic intussusception. Air and Gastrografin(R) enemas were used in an attempt to reduce the intussusception. There were six separate successful intussusception reductions in four patients. Three patients required multiple attempts (2.3 +/- 0.6). Air enemas were used initially in all cases. Gastrografin(R) was used successfully following the failure of air enema in one patient. One patient suffered three separate intussusceptions over a period of 18 months, which were all successfully reduced using air. There were no complications and the patients tolerated the procedure well. Intussusception is an uncommon but serious complication in children with CF. While surgical reduction has been the mainstay of treatment for these patients, we demonstrated that reduction of an intussusception using air or contrast can be accomplished safely, without anesthesia, and should be the initial treatment option.

Left ventricular wall stress in patients with severe aortic insufficiency with finite element analysis.

BACKGROUND: Severe aortic insufficiency (AI) with preserved left ventricular (LV) function may be associated with a long asymptomatic period and unpredictable course on medical therapy. Since myocardial wall stress is closely related to both pathologic cardiac remodeling and ultimately to LV decompensation, a more accurate description of regional wall stress may improve our ability to appropriately manage these patients. The objective of this study was to define differences in instantaneous global and regional three-dimensional end-systolic maximum principal stress (ESS) between normal patients and patients with AI, both before and after aortic valve replacement (AVR) using magnetic resonance imaging (MRI) and finite element analysis (FEA). METHODS: Magnetic resonance imaging was performed on 20 normal volunteers and 14 patients with moderate to severe AI with normal systolic function (ejection fraction: 57 +/- 0.6) before and after AVR. Finite element analysis was utilized to estimate global and regional ESS. RESULTS: Both global (p < 0.001) and regional (p < 0.001 in all segments) ESS were significantly higher in the preoperative AI patients when compared with their postoperative values and normal controls. Postoperative ESS was significantly lower than the normal controls (p = 0.002). CONCLUSIONS: Three-dimensional regional and global end-systolic LV wall stress can be determined by MRI and finite element analysis. Values of ESS in patients with chronic AI were elevated prior to AVR and normalized after AVR. This method may have considerable potential as a noninvasive, clinically applicable index of regional LV geometry and function that may help with the serial evaluation of patients with AI.

Myocardial systolic strain is decreased after aortic valve replacement in patients with aortic insufficiency.

BACKGROUND: Left ventricular three-dimensional nonlinear systolic strain determinations have potential to detect small decrements in ventricular function in patients with aortic insufficiency before and after aortic valve replacement. METHODS: Magnetic resonance imaging with tissue-tagging was performed on 42 normal volunteers and 14 patients with chronic aortic insufficiency both before and 28 +/- 11 months after aortic valve replacement. Preoperative and postoperative left ventricular volume, dimensions and ejection fraction were determined for all subjects. Left ventricular systolic radial, circumferential, longitudinal, and minimum principal strain were calculated for six left ventricular regions. RESULTS: After aortic valve replacement, left ventricular volume and dimensions decreased significantly (p < 0.001) and ejection fraction increased nonsignificantly (p = 0.096). Strain values in preoperative aortic insufficiency patients did not differ significantly from controls. At an average of 28 +/- 11 months postoperatively, however, regional three-dimensional minimum principal and longitudinal strain was decreased in all six ventricular regions as well as globally (p < 0.03) compared with normal control values. Circumferential strain was significantly decreased globally and in all but two regions (p < 0.03). CONCLUSIONS: These magnetic resonance imaging-based techniques are sensitive enough to detect a previously unrecognized, significant decrease in both global and regional three-dimensional left ventricular systolic strain 2 years after aortic valve replacement for minimally symptomatic chronic aortic insufficiency despite improvement in ejection fraction and a decrease in left ventricular size. The reasons for a significant decline in left ventricular systolic strain after successful aortic valve replacement in minimally symptomatic chronic aortic insufficiency patients are not clear and warrant further investigation.

Aortic valve replacement for aortic insufficiency: valve type as a determinant of systolic strain recovery.

BACKGROUND AND AIM: Left ventricular (LV) 3D systolic strain decreases in absolute value postoperatively and does not recover in patients who undergo aortic valve replacement (AVR) for chronic aortic insufficiency (AI). We investigated whether choice of valve prosthesis (mechanical [St. Jude], bioprosthetic [bovine pericardial], Ross procedure) had a significant impact on strain recovery in this surgical population. METHODS: MRI with tissue-tagging was performed on 14 patients with chronic AI both before and 28 +/- 13 months after AVR. Average values of LV systolic strain and end-systolic stress (ESS) were computed from MRI data for the LV. Three types of prosthetic valve were examined (Ross procedure n = 4, bovine pericardial n = 5, and St. Jude n = 5). RESULTS: Overall, systolic strain, ESS, LV volumes, ejection fraction, and LV mass all changed significantly following AVR. Comparisons between individual valve types revealed no differences in any of these measurements. Patients who received a mechanical valve had a greater decrease in the absolute value of systolic strain following surgery compared to patients from the nonmechanical group (Ross procedure and bioprosthetic valve). Comparisons between the Ross group and the prosthetic group (St. Jude and bioprosthetic) produced no significant differences in strain, ESS, LV volume, and mass. CONCLUSIONS: These early results suggest that valve prosthetic type may be a factor in efforts to improve strain recovery after AVR for AI, although further investigation is warranted. MRI with tissue-tagging may be a useful tool for comparing the impact of prosthetic valve choice on incompletely recovered systolic strain following AVR for chronic AI.

Principal strain orientation in the normal human left ventricle.

BACKGROUND: Methods that can improve the accuracy of application of directed intervention in the treatment of coronary artery disease deserve investigation. Magnetic resonance imaging with tissue tagging allows for noninvasive, quantitative determination of regionally varying minimum principal strain. Because the directional vector of minimum principal strain has been shown to be sensitive to ischemic involvement, my colleagues and I sought to fully characterize the normal range of vector direction in the in vivo human left ventricle at rest and during inotropic stimulation. METHODS: Tagged magnetic resonance imaging image sets were acquired in 20 healthy volunteers at rest and during dobutamine infusion. Strain was computed from the measured displacement data by using finite element software. Orientation of minimum principal strain was characterized by measuring the angle (principal strain angle) between the minimum principal strain vector and the local circumferential-longitudinal plane. Values of this angle were computed in 6 ventricular regions and globally. RESULTS: Resting values of the principal strain angle were small in every region, confirming that maximal normal myocardial contraction occurs primarily in the circumferential-longitudinal plane. Angles were similar during dobutamine infusion. Comparisons between ventricular walls, both at rest and with dobutamine, revealed no marked regional differences in the principal strain angle. CONCLUSIONS: The direction of maximal myocardial contraction is known to change with ischemic injury to the myocardium and can be a sensitive, regionally varying index of myocardial ischemia. The critical first step in the clinical application of this technology is to accurately characterize normal ranges of principal strain angles.

Noninvasive, quantitative assessment of left ventricular function in ischemic cardiomyopathy.

BACKGROUND: Coronary artery disease characteristically impacts left ventricular (LV) function on a regional basis, although ultimately global function may be affected as well. Echocardiography is commonly clinically used for the assessment of regional function; however, it is only semiquantitative and in its current iteration is only two-dimensional in nature. Magnetic resonance imaging (MRI) with tissue tagging offers the possibility for noninvasive, three-dimensional (3D) assessment of transmural and segmental left ventricular strain and, thereby, function. Accordingly, we have explored methodologies to accurately and quantitatively characterize regional systolic function in three dimensions in patients with ischemic heart disease using MRI. MATERIALS AND METHODS: MRI radiofrequency tissue tagging was performed at rest and during dobutamine administration (10 mg/kg/min) on 10 normal volunteers (age: 26 +/- 6) and 8 patients with severe ischemic cardiomyopathy (age: 60 +/- 5, EF 26 +/- 11%). Three-dimensional global and regional systolic strain calculations were made based on 3D myocardial point displacements and compared with conventional measures. RESULTS: Global left ventricular strains were significantly decreased in ischemic patients at rest (0.14 +/- 0.04 versus 0.25 +/- 0.02, P < 0.001) and with dobutamine (0.14 +/- 0.03 versus 0.29 +/- 0.03, P < 0.001). In the regional analysis (216 LV wall segments) this methodology accurately differentiated normal from abnormally contracting regions. CONCLUSIONS: Noninvasive dobutamine MRI tissue tagging with calculation of 3D regional strains has significant promise as a clinical tool which is capable of the identification, quantification, and display of regionally varying ventricular function.

Severe aortic insufficiency and normal systolic function: determining regional left ventricular wall stress by finite-element analysis.

BACKGROUND: Because severe aortic insufficiency in the setting of preserved left ventricular function is often associated with a long asymptomatic period and unpredictable course on medical therapy, sensitive indices of left ventricular systolic performance are necessary for the optimal direction of therapeutic intervention. Because myocardial wall stress is closely related to both pathologic cardiac remodeling and ultimately to left ventricular decompensation, an accurate description of regional wall stress distribution may improve our ability to clinically manage these patients appropriately. The objectives of this study were (1) to define sensitive, noninvasive indices of left ventricular systolic performance to assist the clinician in the serial evaluation and early detection of increased left ventricular wall stress and, therefore, inadequate left ventricular remodeling and subsequent myocardial decompensation of patients with aortic insufficiency, and (2) to quantify differences in instantaneous global and regional end-systolic wall stress between normal subjects and patients. METHODS: Magnetic resonance imaging was performed on 23 normal volunteers and 19 patients with aortic insufficiency and normal systolic function (ejection fraction, 57% +/- 6%). Finite-element analysis was used to estimate global and regional end-systolic stress. RESULTS: End-systolic stress was significantly higher in the patient group globally (154,700 +/- 31,711 versus 96,781 +/- 23,185 dyne/cm(2); p < 0.001) and regionally (p < 0.001 in all segments) despite normal systolic function and similar end-systolic pressures. CONCLUSIONS: End-systolic stress as determined by magnetic resonance imaging and finite-element analysis may have considerable potential as a noninvasive, clinically applicable index of regional left ventricular function that may help in the serial evaluation, optimal management, and early identification of left ventricular decompensation in patients with aortic insufficiency.

Neutralization of IL-18 attenuates lipopolysaccharide-induced myocardial dysfunction.

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) have been implicated in cardiac dysfunction during endotoxemia. Because IL-18 is a proinflammatory cytokine known to mediate the production of TNF-alpha and IL-1beta and to induce the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), we hypothesized that neutralization of IL-18 would attenuate lipopolysaccharide (LPS)-induced cardiac dysfunction. Mice (C57BL/6) were injected with LPS (0.5 mg/kg ip) or vehicle (normal saline), and left ventricular developed pressure (LVDP) was determined by the Langendorff technique. LVDP was depressed by 38% at 6 h after LPS. LPS-induced myocardial dysfunction was associated with increased myocardial levels of TNF-alpha and IL-1beta as well as increased expression of ICAM-1/VCAM-1. Pretreatment with neutralizing anti-mouse IL-18 antibody attenuated LPS-induced myocardial dysfunction (by 92%) and was associated with reduced myocardial IL-1beta production (65% reduction) and ICAM-1/VCAM-1 expression (50% and 35% reduction, respectively). However, myocardial TNF-alpha levels were not influenced by neutralization of IL-18. In conclusion, neutralization of IL-18 protects against LPS-induced myocardial dysfunction. IL-18 may mediate endotoxemic myocardial dysfunction through induction of and/or synergy with IL-1beta, ICAM-1, and VCAM-1.

The antitumor histone deacetylase inhibitor suberoylanilide hydroxamic acid exhibits antiinflammatory properties via suppression of cytokines.

Suberoylanilide hydroxamic acid (SAHA) is a hydroxamic acid-containing hybrid polar molecule; SAHA specifically binds to and inhibits the activity of histone deacetylase. Although SAHA, like other inhibitors of histone deacetylase, exhibits antitumor effects by increasing expression of genes regulating tumor survival, we found that SAHA reduces the production of proinflammatory cytokines in vivo and in vitro. A single oral administration of SAHA to mice dose-dependently reduced circulating TNF-alpha, IL-1-beta, IL-6, and IFN-gamma induced by lipopolysaccharide (LPS). Administration of SAHA also reduced hepatic cellular injury in mice following i.v. injection of Con A. SAHA inhibited nitric oxide release in mouse macrophages stimulated by the combination of TNF-alpha plus IFN-gamma. Human peripheral blood mononuclear cells stimulated with LPS in the presence of SAHA released less TNF-alpha, IL-1-beta, IL-12, and IFN-gamma (50% reduction at 100-200 nM). The production of IFN-gamma stimulated by IL-18 plus IL-12 was also inhibited by SAHA (85% at 200 nM). However, SAHA did not affect LPS-induced synthesis of the IL-1-beta precursor, the IL-1 receptor antagonist, or the chemokine IL-8. In addition, IFN-gamma induced by anti-CD3 was not suppressed by SAHA. Steady-state mRNA levels for LPS-induced TNF-alpha and IFN-gamma in peripheral blood mononuclear cells were markedly decreased, whereas IL-8 and IL-1-beta mRNA levels were unaffected. Because SAHA exhibits antiinflammatory properties in vivo and in vitro, inhibitors of histone deacetylase may stimulate the expression of genes that control the synthesis of cytokines and nitric oxide or hyperacetylate other targets.