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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Endovascular Treatment of Two Pseudoaneurysms Originating From the Left Ventricle

A 67-year-old woman resented with an acute type A aortic dissection, which was treated surgically with aortic valve replacement as a composite graft with reimplantation of the coronary arteries. At the end of surgery, a left-ventricular venting catheter was placed through the apex and closed with a buffered suture. Consecutive computed tomography (CT) examinations verified a growing apex pseudoaneurysm. Communication between the ventricle and the pseudoaneurysm was successfully closed with an Amplatz septal plug by the transfemoral route. Follow-up CT showed an additional pseudoaneurysm, which also was successfully closed using the same method.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

The Role of Postintervention Pullback Pressure Gradient in Percutaneous Transluminal Angioplasty for Central Vein Stenosis in Dialysis Patients

Purpose: The severity of residual stenosis (RS) sometimes cannot be accurately measured by angiography during central vein intervention. This study evaluated the role of pullback pressure measurement during central vein stenosis (CVS) intervention. Methods: A retrospective review enrolled 94 consecutive dialysis patients who underwent CVS interventions but not stenting procedures. Patients were classified into 2 groups by either angiography or pressure gradient (PG) criteria, respectively. Groups divided by angiographic result were successful group (RS {<=}30 %) and acceptable group (50 % {>=} RS > 30 %), while groups divided by PG were low PG group (PG {<=}5 mmHg) and high PG group (PG >5 mmHg). Baseline characteristics and 12-month patency rates between the groups were analyzed. Results: The angiography results placed 63 patients in the successful group and 31 patients in the acceptable group. The patency rate at 12 month was not statistically different (P = 0.167). When the patients were reclassified by the postintervention pullback PG, the patency rate at 12 months was significant (P = 0.048). Further analysis in groups redivided by different combinations of RS and PG criteria identified significant differences in the group with both RS {<=}30 % and PG {<=}5 mmHg compared with those with either RS >30 % (P = 0.047) or PG >5 mmHg (P = 0.027). In addition, there was a significant difference between those with both RS {<=}30 % and PG {<=}5 mmHg compared with those with both RS >30 % and PG >5 mmHg (P = 0.027). Conclusion: Postintervention PG can better predict long-term outcomes after angioplasty for CVS in nonstented dialysis patients than angiography.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Two Cases of Postmyomectomy Pseudoaneurysm Treated by Transarterial Embolization

Pseudoaneurysm resulting from hysteroscopic myomectomy is a rare clinical situation, and interventional radiologists are not traditionally involved in the management. To our knowledge, endovascular treatment of a pseudoaneurysm resulting from hysteroscopic myomectomy has not yet been reported in the English-language literature. Here, two such cases are reported, including one of a woman who later became pregnant. The case is unique because little is known about the influence of unilateral coil embolization of the uterine artery on fertility.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Fluoroscopically Guided Balloon Dilation for Postintubation Tracheal Stenosis

Purpose: Little was known about the safety and long-term efficacy of fluoroscopically guided balloon dilation for postintubation tracheal stenosis. The purpose of this study was to evaluate the safety and long-term efficacy of fluoroscopically guided balloon dilation in patients with postintubation tracheal stenosis. Methods: From February 2000 to November 2010, 14 patients underwent fluoroscopically guided balloon dilation for postintubation tracheal stenosis. Technical success, clinical success, and complications were evaluated. Patients were followed up for recurrent symptoms. Results: In all patients, fluoroscopically guided balloon dilation was technically and clinically successful with no major complications. Following the initial procedure, six patients (43 %) remained asymptomatic during a follow-up period. Obstructive symptoms recurred in eight patients (57 %) within 6 months (mean, 1.7 months), who were treated with repeat balloon dilation (n = 4) and other therapies. Of the four patients who underwent repeat balloon dilation, three became asymptomatic. One patient became asymptomatic after a third balloon dilation. On long-term (mean, 74 months) follow-up, 71 % of patients experienced relief of symptoms following fluoroscopically guided balloon dilation. Conclusions: Fluoroscopically guided balloon dilation may be safe, is easy to perform, and resulted in effective treatment in patients with postintubation tracheal stenosis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

MRI Assessment of Uterine Artery Patency and Fibroid Infarction Rates 6 Months after Uterine Artery Embolization with Nonspherical Polyvinyl Alcohol

Purpose: We have observed significant rates of uterine artery patency after uterine artery embolization (UAE) with nonspherical polyvinyl alcohol (nsPVA) on 6 month follow-up MR scanning. The study aim was to quantitatively assess uterine artery patency after UAE with nsPVA and to assess the effect of continued uterine artery patency on outcomes. Methods: A single centre, retrospective study of 50 patients undergoing bilateral UAE for uterine leiomyomata was undertaken. Pelvic MRI was performed before and 6 months after UAE. All embolizations were performed with nsPVA. Outcome measures included uterine artery patency, uterine and dominant fibroid volume, dominant fibroid percentage infarction, presence of ovarian arterial collaterals, and symptom scores assessed by the Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL). Results: Magnetic resonance angiographic evidence of uterine artery recanalization was demonstrated in 90 % of the patients (64 % bilateral, 26 % unilateral) at 6 months. Eighty percent of all dominant fibroids demonstrated >90 % infarction. The mean percentage reduction in dominant fibroid volume was 35 %. No significant difference was identified between nonpatent, unilateral, and bilateral recanalization of the uterine arteries with regard to percentage dominant fibroid infarction or dominant fibroid volume reduction. The presence of bilaterally or unilaterally patent uterine arteries was not associated with inferior clinical outcomes (symptom score or UFS-QOL scores) at 6 months. Conclusion: The high rates of uterine artery patency challenge the current paradigm that nsPVA is a permanent embolic agent and that permanent uterine artery occlusion is necessary to optimally treat uterine fibroids. Despite high rates of uterine artery recanalization in this cohort, satisfactory fibroid infarction rates and UFS-QOL scores were achieved.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Transarterial Embolization of Type II Endoleaks after EVAR: The Role of Ethylene Vinyl Alcohol Copolymer (Onyx)

Purpose: To determine the feasibility and efficacy of transarterial endoleak embolization using the liquid embolic agent ethylene vinyl alcohol copolymer (Onyx). Methods: Over a 7-year period eleven patients (6 women, 5 men; mean age 68 years, range 37-83 years) underwent transarterial embolization of a type II endoleak after endovascular aortic aneurysm repair using the liquid embolic agent Onyx. Two patients (18 %) had a simple type II endoleak with only one artery in communication with the aneurysm sac, whereas 9 patients (82 %) had a complex type II endoleak with multiple communicating vessels. We retrospectively analyzed the technical and clinical success of transarterial type II endoleak embolization with Onyx. Complete embolization of the nidus was defined as technical success. Embolization was considered clinically successful when volume of the aneurysm sac was stable or decreased on follow-up CT scans. Result: Mean follow-up time was 26.0 (range 6-50) months. Clinical success was achieved in 8 of 11 patients (73 %). Transarterial nidus embolization with Onyx was technically successful in 6 of 11 patients (55 %). In three cases the nidus was embolized without direct catheterization from a more distal access through the network of collateral vessels. Conclusion: Onyx is a favorable embolic agent for transarterial endoleak embolization. To achieve the best clinical results, complete occlusion of the nidus is mandatory.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Staged Transcatheter Treatment of Portal Hypoplasia and Congenital Portosystemic Shunts in Children

Purpose: Congenital portosystemic shunts (CPSS) with portal venous hypoplasia cause hyperammonemia. Acute shunt closure results in portal hypertension. A transcatheter method of staged shunt reduction to afford growth of portal vessels followed by shunt closure is reported. Methods: Pressure measurements and angiography in the CPSS or superior mesenteric artery (SMA) during temporary occlusion of the shunt were performed. If vessels were diminutive and the pressure was above 18 mmHg, a staged approach was performed, which included implantation of a tailored reducing stent to reduce shunt diameter by {approx}50 %. Recatheterization was performed approximately 3 months later. If the portal pressure was below 18 mmHg and vessels had developed, the shunt was closed with a device. Results: Six patients (5 boys, 1 girl) with a median age of 3.3 (range 0.5-13) years had CPSS portal venous hypoplasia and hyperammonemia. Five patients underwent staged closure. One patient tolerated acute closure. One patient required surgical shunt banding because a reducing stent could not be positioned. At median follow-up of 3.8 (range 2.2-8.4) years, a total of 21 procedures (20 transcatheter, 1 surgical) were performed. In all patients, the shunt was closed with a significant reduction in portal pressure (27.7 {+-} 11.3 to 10.8 {+-} 1.8 mmHg; p = 0.016), significant growth of the portal vessels (0.8 {+-} 0.5 to 4.0 {+-} 2.4 mm; p = 0.037), and normalization of ammonia levels (202.1 {+-} 53.6 to 65.7 {+-} 9.6 {mu}mol/L; p = 0.002) with no complications. Conclusion: Staged CPSS closure is effective in causing portal vessel growth and treating hyperammonemia.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Alternative Treatment for Bleeding Peristomal Varices: Percutaneous Parastomal Embolization

Purpose: To describe how peristomal varices can be successfully embolized via a percutaneous parastomal approach. Methods: The medical records of patients who underwent this procedure between December 1, 2000, and May 31, 2008, were retrospectively reviewed. Procedural details were recorded. Median fluoroscopy time and bleeding-free interval were calculated. Results: Seven patients underwent eight parastomal embolizations. The technical success rate was 88 % (one failure). All embolizations were performed with coils combined with a sclerosant, another embolizing agent, or both. Of the seven successful parastomal embolizations, there were three cases of recurrent bleeding; the median time to rebleeding was 45 days (range 26-313 days). The remaining four patients did not develop recurrent bleeding during the follow-up period; their median bleeding-free interval was 131 days (range 40-659 days). Conclusion: This case review demonstrated that percutaneous parastomal embolization is a feasible technique to treat bleeding peristomal varices.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Metallic Stents for Tracheobronchial Pathology Treatment

Purpose: To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. Patients and Methods: One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Results: The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 {+-} 1.2 months in patients with malignant lesions and 76.2 {+-} 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Conclusion: Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Cutting-Balloon Angioplasty Versus Balloon Angioplasty as Treatment for Short Atherosclerotic Lesions in the Superficial Femoral Artery: Randomized Controlled Trial

Purpose: To evaluate the treatments of a short-segment atherosclerotic stenosis in the superficial femoral arteries with the cutting balloon angioplasty (CBA) versus conventional balloon angioplasty [percutaneous transluminal angioplasty (PTA)] in a randomized controlled trial. Material and Methods: The study group comprised 60 patients (33 men, 27 women; average age 64 years) with a short ({<=}5 cm) focal SFA de novo atherosclerotic stenosis associated with a history of intermittent claudication or rest pain. The primary end point of this study was the rate of binary restenosis in the treated segment 12 months after the intervention. All patients were evenly randomized to either the PTA or CBA treatment arms. Follow-up angiograms and ankle-brachial index (ABI) measurements were performed after 12 months. The evaluation of the restenosis rates and factors influencing its occurrence were calculated by logistic regression analysis. Results: In the intention-to-treat analysis, restenosis rates after 2-month follow-up were 9 of 30 (30 %) in the PTA group and 4 of 30 (13 %) in the CBA group (p = 0.117). In the actual treatment analysis, after exclusion of patients who required nitinol stent placement for a suboptimal result after angioplasty alone (5 patients in the PTA group and none in the CBA group), restenosis rates were 9 of 25 (36 %) and 4 of 30 (13 %), respectively (p = 0.049). In the intention-to-treat analysis there were also significant differences in ABI values between the PTA and CBA groups at 0.77 {+-} 0.11 versus 0.82 {+-} 0.12, respectively (p = 0.039), at 12 months. Conclusion: Based on the presented results of the trial, CBA seems to be a safer and more effective than PTA for treatment of short atherosclerotic lesions in the superior femoral artery.

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