Radiation recall reaction causing cardiotoxicity.

Radiation recall phenomenon is a tissue reaction that develops within a previously irradiated area, precipitated by the subsequent administration of certain chemotherapeutic agents. It commonly affects the skin, but can also involve internal organs with functional consequences. To our best knowledge, this phenomenon has never been reported as a complication on the heart and should be consider as a potential cause of cardiotoxicity.

Outcomes of venoplasty with stent placement for chronic thrombosis of the iliac and femoral veins: single-center experience.

PURPOSE: To assess retrospectively 30-day, 1-year, and 3-year patency of chronically occluded iliofemoral venous thrombotic lesions treated with stent placement in a case series from a single institution. MATERIALS AND METHODS: Records of 189 consecutive patients treated by interventional radiology for iliofemoral venous occlusions between March 1, 2003, and December 1, 2008, were retrospectively reviewed. A total of 89 patients (27 men; median age, 46.2 y) with chronic iliac or iliofemoral deep vein thrombosis without involvement of the inferior vena cava met criteria for analysis. RESULTS: All patients (91 limbs) successfully underwent placement of venous self-expanding stents. Patency rate at discharge was 100%. Following the index procedure, mean pressure gradient across the lesion decreased from 5.63 mm Hg (95% CI, 3.51-7.75) to 0.71 mm Hg (95% CI, 0.08-1.34; P < .0001). There were no bleeding complications. Median follow-up was 11.3 months (range, 0.8-72.4 mo). Follow-up at 30 days demonstrated 90 of 91 limbs to be patent. Primary patency rates of treated limbs at 1 and 3 years were 81% and 71%, respectively. Primary patency was lost in 17 cases (19.1%); interventions to maintain or restore stent patency were performed in 13 cases (14.6%). Primary assisted limb patency rates at 1 and 3 years were 94% and 90%, respectively; secondary patency rate was 95%. CONCLUSIONS: Angioplasty with stent placement for treatment of chronically thrombosed iliofemoral veins is a low-risk procedure with acceptable patency rates for as long as 3 years. The outcomes in patients treated in a quaternary referral center are similar to those reported by other centers.

In vitro thermal profile suitability assessment of acids and bases for thermochemical ablation: underlying principles.

PURPOSE: To measure and compare temperature changes in a recently developed gel phantom for thermochemical ablation as a function of reagent strength and concentration with several acids and bases. MATERIALS AND METHODS: Aliquots (0.5-1 mL) of hydrochloric acid or acetic acid and sodium hydroxide or aqueous ammonia were injected for 5 seconds into a hydrophobic gel phantom. Stepwise increments in concentration were used to survey the temperature changes caused by these reactions. Injections were performed in triplicate, measured with a thermocouple probe, and plotted as functions of concentration and time. RESULTS: Maximum temperatures were reached almost immediately in all cases, reaching 75 degrees C-110 degrees C at the higher concentrations. The highest temperatures were seen with hydrochloric acid and either base. More concentrated solutions of sodium hydroxide tended to mix incompletely, such that experiments at 9 M and higher were difficult to perform consistently. CONCLUSIONS: Higher concentrations for any reagent resulted in higher temperatures. Stronger acid and base combinations resulted in higher temperatures versus weak acid and base combinations at the same concentration. Maximum temperatures obtained are in a range known to cause tissue coagulation, and all combinations tested therefore appeared suitable for further investigation in thermochemical ablation. Because of the loss of the reaction chamber shape at higher concentrations of stronger agents, the phantom does not allow complete characterization under these circumstances. Adequate mixing of reagents to maximize heating potential and avoid systemic exposure to unreacted acid and base must be addressed if the method is to be safely employed in tissues. In addition, understanding factors that control lesion shape in a more realistic tissue model will be critical.

Use of kissing embolic protection devices in the treatment of early bifurcation renal artery stenosis: a case report.

Renal artery stenosis (RAS) is a progressive disease that may cause hypertension and chronic renal insufficiency. Percutaneous renal artery angioplasty with stent placement is a well-recognized treatment for atherosclerotic RAS. It can infrequently involve the bifurcation, and treatment of this stenosis has been described using bare metal and drug-eluting stents deployed simultaneously in a kissing fashion. Atheroembolism is believed to be caused by the release of microscopic plaque fragments and cholesterol crystals from the RAS or atherosclerotic aorta. Herein, the authors describe the use of a kissing embolic protection device technique during renal artery stent placement.

A hydrophobic gel phantom for study of thermochemical ablation: initial results using a weak acid and weak base.

PURPOSE: To develop a model for study of exothermic chemical reactions potentially useful for tissue ablation. MATERIALS AND METHODS: Seven gelatins ranging from 0.5% to 30% wt/vol with and without 15% or 30% caps and several commercial gels were evaluated. Baseline temperature measurements were taken. Acetic acid and ammonium hydroxide were sequentially injected over periods of 10-15 seconds in 1-mL aliquots, forming a discrete aqueous reaction chamber. Congo red pH indicator was included to assess the reaction. A thermocouple allowed data collection at completion of injection and every 15 seconds for 5 minutes. Injections were performed in triplicate, and average temperatures for each time point were reported. RESULTS: Gelatins fractured or refluxed even at the lowest concentrations tested. Most commercial gels proved too viscous and likewise led to reflux along the needle tract. A mineral oil-based gel was selected because of its ability to form a chamber without reflux or fracture and its clear colorless character, hydrophobic nature, chemical stability, viscosity, specific gravity, and cost. Temperatures during the first 60 seconds of the neutralization reaction showed an immediate increase that correlated well with concentration. CONCLUSIONS: The oil gel phantom is a safe, useful, readily available, inexpensive model to study mixing behaviors and maximum heating potentials for reactions that may prove useful in thermochemical tissue ablation for oncologic interventions. Measurable temperature changes occurred even at the lowest concentrations, and higher concentrations produced a greater release of heat energy.

Cardiac MR imaging of nonischemic cardiomyopathies.

Cardiomyopathies, diseases of the myocardium associated with cardiac dysfunction, include hypertrophic, restrictive, and dilated forms and rare entities, such as arrhythmogenic right ventricular dysplasia, ventricular noncompaction, and apical ballooning syndrome. Many have similar presentations, but the underlying condition determines prognoses and treatment. Cardiac MR imaging plays a role in characterizing the range of entities and is crucial for evaluation and management. In addition, delayed enhanced imaging can allow differentiation among the forms of cardiomyopathy and offer prognostic information. As the speed and technical ease of cardiac imaging improve, MR imaging will assume an increasing role in the care of patients who have cardiomyopathy.

MR imaging of the pericardium.

Imaging of the pericardium requires understanding of anatomy and the normal and abnormal physiology of the pericardium. MR imaging is well-suited for answering clinical questions regarding suspected pericardial disease. Pericardial diseases that may be effectively imaged with MR imaging include pericarditis, pericardial effusion, cardiac-pericardial tamponade, constrictive pericarditis, pericardial cysts, absence of the pericardium, and pericardial masses. Although benign and malignant primary tumors of the pericardium may be occasionally encountered, the most common etiology of a pericardial mass is metastatic disease.

MR imaging of cardiac masses.

Cardiac MR imaging is the preferred method for assessment of cardiac masses. A comprehensive cardiac MR imaging examination for a cardiac mass consists of static morphologic images using fast spin-echo sequences, including single-shot techniques, with T1 and T2 weighting and fat suppression pulses as well as dynamic imaging with cine steady-state free precession techniques. Further tissue characterization is provided with perfusion and delayed enhancement imaging. Specific cardiac tumoral characterization is possible in many cases. When specific tumor characterization is not possible, MR imaging often can demonstrate aggressive versus nonaggressive features that help in differentiating malignant from benign tumors.