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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Image-Guided Intraoperative Assessment of Surgical Margins in Oral Cavity Squamous Cell Cancer: A Diagnostic Test Accuracy Review

The assessment of resection margins during surgery of oral cavity squamous cell cancer (OCSCC) dramatically impacts the prognosis of the patient as well as the need for adjuvant treatment in the future. Currently there is an unmet need to improve OCSCC surgical margins which appear to be involved in around 45% cases. Intraoperative imaging techniques, magnetic resonance imaging (MRI) and intraoral ultrasound (ioUS), have emerged as promising tools in guiding surgical resection, although the number of studies available on this subject is still low. The aim of this diagnostic test accuracy (DTA) review is to investigate the accuracy of intraoperative imaging in the assessment of OCSCC margins. By using the Cochrane-supported platform Review Manager version 5.4, a systematic search was performed on the online databases MEDLINE-EMBASE-CENTRAL using the keywords “oral cavity cancer, squamous cell carcinoma, tongue cancer, surgical margins, magnetic resonance imaging, intraoperative, intra-oral ultrasound”. Ten papers were identified for full-text analysis. The negative predictive value (cutoff < 5 mm) for ioUS ranged from 0.55 to 0.91, that of MRI ranged from 0.5 to 0.91; accuracy analysis performed on four selected studies showed a sensitivity ranging from 0.07 to 0.75 and specificity ranging from 0.81 to 1. Image guidance allowed for a mean improvement in free margin resection of 35%. IoUS shows comparable accuracy to that of ex vivo MRI for the assessment of close and involved surgical margins, and should be preferred as the more affordable and reproducible technique. Both techniques showed higher diagnostic yield if applied to early OCSCC (T1–T2 stages), and when histology is favorable.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

Characteristics of a Laser Resonant Ultrasonic Spectroscopy System for Measuring the Elastic Constants of Materials

Resonant ultrasound spectroscopy (RUS) is a useful technique for measuring the elastic properties of materials. In this study, two experimental approaches for performing RUS are experimentally analyzed and compared: 1) contact transduction using piezoelectric transducers (PZT) and 2) laser transduction using pulse laser excitation and laser interferometric detection. A single Zircaloy sample cut from a nuclear pressure tube was used for this study. By virtue of the non-contact nature, the quality factor, Q, for laser RUS is shown to be higher than the contact RUS. In addition, the probe beam for laser-RUS can be scanned to form a 2D image of each vibrational mode, which in turn enables unique mode identification. These defining characteristics of laser-RUS enable straightforward discrimination of closely spaced resonant modes and provide key advantages for improving the resolution of resonant ultrasound spectroscopy.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS2018

Automated Pneumothorax Diagnosis using Deep Neural Networks

Thoracic ultrasound can provide information leading to rapid diagnosis of pneumothorax with improved accuracy over the standard physical examination and with higher sensitivity than anteroposterior chest radiography. However, the clinical We have Furthermore, remote environments, such as the battlefield or deep-space exploration, may lack expertise for diagnosing developed an automated image interpretation pipeline for the analysis of thoracic ultrasound data and the classification of pneumothorax events to provide decision support in such situations. Our pipeline consists of image preprocessing, data augmentation, and deep learning architectures for medical diagnosis. In this work, we demonstrate that robust, accurate interpretation of chest images and video can be achieved using deep neural networks. A number of novel image processing techniques were employed to achieve this result. Affine transformations were applied for data augmentation. Hyperparameters were optimized for learning rate, dropout regularization, batch size, and epoch iteration by a sequential model-based Bayesian approach. In addition, we utilized pretrained architecturesinterpretation of a patient medical image is highly operator dependent. certain pathologies., applying transfer learning and fine-tuning techniques to fully connected layers. Our pipeline yielded binary classification validation accuracies of 98.3% for M-mode images and 99.8% with B-mode video frames.

US Army collaboration↗
NASA NTRSDate not supplied

Acquisition and Processing of Passive Thermography Fatigue Test Data

Passive thermography is a large area inspection technique and is commonly used during fatigue loading of composite structures. Passive thermography allows for real time tracking of damage. This provides an accurate assessment of the damage progression as a function of load cycles and determines when the loading is stopped for ultrasonic or X-ray CT evaluations for detail damage assessment through-the-thickness. In addition, if new areas of damage growth are detected, with passive thermography, then those areas are additionally inspected with ultrasound or X-ray CT. A custom developed passive thermography inspection system for fatigue loading is presented. Passive thermography of damage progression is compared to ultrasound inspections as a function of the fatigue cycles. Discussion is made on processing of the thermal data for periodic and non-periodic thermal responses.

Thermal nondestructive evaluation↗
NASA NTRSDate not supplied

NDE Methods and Capabilities Handbook - Resources for the Composites NDE Community

Composite structures are often difficult to inspect due to the anisotropic nature of the material systems and the range of flaws and defects that can arise in the manufacturing process. NASA’s Advanced Composites Project, a public-private partnership between government, universities and industry, sought to address improved methods, tools, and protocols to reduce the development and certification timeline for composite materials and structures. The rapid inspection of composites was one of the three focused research areas of the project. One deliverable of the project was to develop an NDE Methods and Capabilities Handbook. This Handbook provides a publicly available guidance document that facilitates the selection of appropriate NDE techniques and provides recommended protocols for detecting and characterizing common flaw types in solid laminate carbon fiber reinforced polymer composite (CFRP) structures. The Handbook seeks to reduce the time required to develop qualified inspection processes for composite aircraft structures during the development, certification, and manufacturing phases by providing a reference that helps minimize trial and error and provides guidance on best practices, techniques, and settings, for specific flaw types and geometries. Techniques include, but are not limited to ultrasound, laser based ultrasound, infrared thermography, and x-ray CT. Flaw types include, but are not limited to porosity, delaminations, voids, Automated Fiber Placement (AFP) defects and impact damage. The Handbook contains details such as inspection parameters, data analysis techniques, inspection efficiency and limitations. This presentation will describe key Handbook activities with examples of the techniques and flaw types examined by the Advanced Composite Consortium members. Availability to the NDE community of the fabricated NDE standards as well as the raw data collected on the standards by the Consortium members is discussed.

Nondestructive Evaluation↗
NASA NTRSDate not supplied

NDE Methods and Capabilities Handbook - Resources for the Composites NDE Community

Composite structures are often difficult to inspect due to the anisotropic nature of the material systems and the range of flaws and defects that can arise in the manufacturing process. NASA’s Advanced Composites Project, a public-private partnership between government, universities and industry, sought to address improved methods, tools, and protocols to reduce the development and certification timeline for composite materials and structures. The rapid inspection of composites was one of the three focused research areas of the project. One deliverable of the project was to develop an NDE Methods and Capabilities Handbook. This Handbook provides a publicly available guidance document that facilitates the selection of appropriate NDE techniques and provides recommended protocols for detecting and characterizing common flaw types in solid laminate carbon fiber reinforced polymer composite (CFRP) structures. The Handbook seeks to reduce the time required to develop qualified inspection processes for composite aircraft structures during the development, certification, and manufacturing phases by providing a reference that helps minimize trial and error and provides guidance on best practices, techniques, and settings, for specific flaw types and geometries. Techniques include, but are not limited to ultrasound, laser based ultrasound, infrared thermography, and x-ray CT. Flaw types include, but are not limited to porosity, delaminations, voids, Automated Fiber Placement (AFP) defects and impact damage. The Handbook contains details such as inspection parameters, data analysis techniques, inspection efficiency and limitations. This paper describes key Handbook activities with examples of the techniques and flaw types examined by the Advanced Composite Consortium members. Availability to the NDE community of the fabricated NDE standards as well as the raw data collected on the standards by the Consortium members is discussed.

nondestructive evaluation↗
DOE OSTI2021

Systematic Design and Experimental Demonstration of Transmission-Type Multiplexed Acoustic Metaholograms

Acoustic holograms have promising applications in sound-field reconstruction, particle manipulation, ultrasonic haptics, and therapy. This study reports on the theoretical, numerical, and experimental investigation of multiplexed acoustic holograms at both audio and ultrasonic frequencies via a rationally designed transmission-type acoustic metamaterial. The proposed metahologram is composed of two Fabry–Pérot resonant channels per unit cell, which enables the simultaneous modulation of the transmitted amplitude and phase at two desired frequencies. In contrast to conventional acoustic metamaterial-based holograms, the design strategy proposed here provides a new degree of freedom (frequency) that can actively tailor holograms that are otherwise completely passive and significantly enhances the information encoded in acoustic metamaterials. To demonstrate the multiplexed acoustic metamaterial, the projection of two different high-quality metaholograms is first shown at 14 and 17 kHz, with the patterns of the letters N and S. Then, two-channel ultrasound focusing and annular beams generation for the incident ultrasonic frequencies of 35 and 42.5 kHz are demonstrated. Furthermore, these multiplexed acoustic metaholograms offer a technical advance to tackle the rising challenges in the fields of acoustic metamaterials, architectural acoustics, and medical ultrasound.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Pain in percutaneous liver core-needle biopsy: a randomized trial comparing the intercostal and subcostal approaches

Purpose: Effective pain control during and after percutaneous core needle liver biopsy is important with regard to ethical considerations and patient comfort. In this randomized double-blind study, we compared post-biopsy pain in the patients undergoing liver core-needle biopsy using either subcostal or intercostal approaches. Methods: All patients referred for ultrasound-guided CNLB between July 2017 and January 2018 to our interventional radiology department were randomized into two groups. Biopsy was performed through intercostal approach in the first group and through subcostal approach in the second group. The intensity of pain 0, 2, and 4 h after the procedure was compared in two groups using a 100-mm visual analogue scale. All biopsies were performed without procedural IV sedation. If patients’ discomfort demanded administration of IV analgesics during or after the procedure, then the patients were excluded from the study. Results: In patients without routine procedural IV sedation, there was no significant difference in the pain level between the intercostal and subcostal groups immediately after the procedure (p = 0.055), but we found a significant difference in the pain level between the two groups 2 (7.5 mm, p = 0.001) and 4 (2 mm, p = 0.001) h after the procedure. Conclusion: The minimum amount of change in the VAS score that is considered clinically important is 13 mm on a 100-mm scale. Pain differences at 2 and 4 h in the two groups in this study were statistically but not clinically significant. Therefore, the authors suggest the use of subcostal route for ultrasound-guided liver biopsy whenever possible, but the results do not warrant the routine use of post-procedure analgesics in whom biopsy is performed via intercostal route.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Endovenous Laser Ablation as a Treatment for Postsurgical Recurrent Saphenous Insufficiency

The purpose of this study was to investigate the safety and efficacy of endovenous laser ablation as a treatment for recurrent symptomatic saphenous insufficiency occurring after saphenous vein ligation and stripping. A single-center retrospective review of patients who received endovenous laser ablation as a treatment for recurrent symptomatic saphenous insufficiency after ligation and stripping between November 2003 and October 2006 was performed. Fifty-six insufficient saphenous systems were identified in 38 patients. Follow-up consisted of a clinical examination in all patients as well as selective lower-extremity duplex ultrasound as clinically indicated. All 38 patients demonstrated complete closure of the insufficient saphenous vein by clinical examination and/or duplex ultrasound evaluation. Preoperative symptoms resolved after treatment in all 38 patients. No major complications were identified. Endovenous laser ablation of recurrent symptomatic saphenous venous insufficiency is a safe and effective treatment in patients who develop recurrent symptoms after saphenous vein ligation and stripping.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2010

Peripherally Placed Totally Implantable Venous-access Port Systems of the Forearm: Clinical Experience in 763 Consecutive Patients

The aim of this study is to evaluate the effectiveness and safety of percutaneously placed totally implantable venous-access ports (TIVAPs) of the forearm. Between January 2006 and October 2008, peripheral TIVAPs were implanted in 763 consecutive patients by ultrasound and fluoroscopic guidance. All catheters were implanted under local anesthesia and were tunneled subcutaneously. Indication, technical success, and complications were retrospectively analyzed according to Society of Interventional Radiology (SIR) criteria. Presence of antibiotic prophylaxis, periprocedurally administered drugs (e.g., sedation), and laboratory results at the time of implantation were analyzed. Maintenance during the service interval was evaluated. In total, 327,499 catheter-days were analyzed. Technical success rate was 99.3%. Reasons for initial failure of implantation were either unexpected thrombosis of the subclavian vein, expanding tumor mass of the mediastinum, or failure of peripheral venous access due to fragile vessels. Mean follow-up was 430 days. There were 115 complications observed (15.1%, 0.03 per 100 catheter-days), of which 33 (4.3%) were classified as early (within 30 days from implantation) and 82 (10.7%) as late. Catheter-related venous thrombosis was found in 65 (8.5%) of 763 (0.02 per 100 catheter-days) TIVAPs. Infections were observed in 41 (5.4%) of 763 (0.01 per 100 catheter-days) devices. Other complications observed included dislocation of the catheter tip (0.8%), occlusion (0.1%), or rupture (0.1%) of the port catheter. Dislocated catheters were corrected during a second interventional procedure. In conclusion, implantation of percutaneously placed peripheral TIVAPs shows a high technical success rate and low risk of early complications when ultrasound and fluoroscopic guidance are used. Late complications are observed three times as often as early complications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Long-Term Safety and Effectiveness of the 'OptEase' Vena Cava Filter

Purpose: To assess the long-term safety and effectiveness of the OptEase inferior vena cava (IVC) filter. Materials and Methods: In this Institutional Review Board-approved, retrospective study, we reviewed data of 71 patients who received an OptEase filter at our institution from 2002 to 2007. Thirty-nine (55%) patients had symptoms of venous thromboembolism before filter placement. The indications for filter included contraindication to anticoagulation in 31 (44%) patients, prophylaxis against pulmonary embolism (PE) in 29 (41%) patients, and failure of anticoagulation in 11 (15%) patients. Procedure-related complications, such as symptomatic post-filter PE, deep venous thrombosis (DVT), IVC occlusion, and incidental imaging-evident filter-related complications, were recorded. Safety was assessed by the occurrence of filter-related complications during placement and follow-up. Effectiveness was assessed by the occurrence of post-filter PE. Results: Sixty-five (92%) filters were placed under fluoroscopy, and 6 (8%) were placed using intravascular ultrasound guidance. Seventy (99%) filters were placed successfully. Seven (10%) filters were placed in the suprarenal cava. Retrieval was attempted in 14 (20%) patients, and 12 filters were successfully retrieved. Clinical follow-up was available for 20 {+-} 21 months. Symptoms of postfilter PE and DVT occurred in 15% (n = 11) and 10% (n = 7) patients, respectively. None of these patients had computed tomography (CT)-proven PE, and only one had ultrasound-proven new DVT. One patient had symptomatic IVC occlusion. Follow-up abdominal CT in 20 patients showed thrombus in the filter in two of them. There were no instances of filter migration, filter tilt, or caval wall penetration. Conclusion: The OptEase filter appears to have an acceptable long-term safety profile. The filter was effective against PE.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

A Novel Carotid Device for Embolic Diversion: Lessons Learned from a 'First in Man' Trial in Patients with Atrial Fibrillation

Purpose: This study was designed to investigate a novel device that was developed to direct emboli away from the internal carotid artery to the external carotid artery to prevent embolic stroke while avoiding the necessity for anticoagulation with warfarin. Methods: A stent-like, self-expandable filter was developed consisting of fine cobalt alloy mesh. After promising preclinical animal testing, the device was implanted into the common carotid artery extending into the external carotid artery in three patients with atrial fibrillation, each of whom were at high-risk for cerebral emboli and were suboptimal candidates for anticoagulation. Follow-up was performed clinically and with carotid duplex ultrasound. Results: The implantation was successful in all three patients. Unrestricted flow through the filter was demonstrated in each patient at 6 months by duplex sonography. However, at 7 months ultrasound demonstrated occlusion of the internal carotid artery filter in one patient, which was subsequently confirmed by angiography. Subtotal filter occlusion occurred in a second patient at 14 months. Neither patient had clinical symptoms. Both internal carotid arteries were successfully recanalized using standard angioplasty techniques without complication. The third patient had completely normal carotid blood flow at 29 months follow-up. Conclusions: Implantation of a novel device intended to divert emboli away from the internal carotid artery was feasible, but resulted in occlusive neointimal proliferation in two of three patients. These results demonstrate a discrepancy from the findings of preclinical animal studies and human investigation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Endovenous Laser Ablation and Concomitant Foam Sclerotherapy: Experience in 504 Patients

Purpose: To investigate the value of endovenous laser ablation (ELA) and concomitant ultrasound-guided foam sclerotherapy (USGFS) in patients with chronic venous insufficiency. Methods: During a 6-year period, concomitant USGFS of the varicose veins were performed in 504 out of 610 patients who underwent ELA for truncal or perforating vein insufficiency. In these 504 patients (944 legs; bilateral in 440 patients), the incompetent veins were greater saphenous vein in 615 legs, small saphenous vein in 118 veins, perforating veins in 42 legs, and a combination of these in 169 legs. In all patients, after ELA of the incompetent veins, USGFS was performed for the remaining varicosities with 1-3% polidocanol foam. Patients were followed up clinically and with color Doppler ultrasound at 1, 6, and 12 months. Results: ELA was technically successful in all cases, although another venous puncture was necessary in 29 legs. Concomitant USGFS was also technically successful in all cases, but one to three additional sclerotherapy sessions were performed in 203 legs with persistent varicosities. During the follow-up, recanalization of the laser-ablated refluxing veins occurred in 16 legs (1.7%) and was treated with repeat ELA or USGFS. Major complications occurred in 1.4% of the treated legs and included skin necrosis and calf vein thrombosis. Conclusion: ELA and concomitant foam sclerotherapy is feasible and effective. The procedures are associated with a low complication rate and can be performed in both legs in the same session. Concomitant use of laser and foam may potentially decrease the recanalization rate of laser-ablated vessels.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Efficacy and Safety of a Novel Vascular Closure Device (Glubran 2 Seal) After Diagnostic and Interventional Angiography in Patients with Peripheral Arterial Occlusive Disease

To prospectively evaluate safety and efficacy of a novel vascular closure device (Glubran 2 Seal) after peripheral angiography in patients with peripheral arterial occlusive disease (PAOD). From December 2010 to June 2011, all consecutive patients with PAOD undergoing peripheral angiography were prospectively enrolled onto the study after percutaneous antegrade or retrograde puncture of the common femoral artery. After angiography, the Glubran 2 Seal device was used to achieve hemostasis. The following data were registered: technical success and manual compression duration, patients' discomfort (scale 0-5), operators' technical difficulty (scale 0-5), and vascular complications. The site of hemostasis was evaluated by clinical inspection and color-coded Duplex ultrasound performed 1 day and 1 month after the procedure. One hundred seventy-eight patients were enrolled (112 male, mean age 70.8 years) with a total of 206 puncture sites, including 104 (50.5 %) antegrade accesses. The device was successful in 198(96.1 %) of 206 procedures, with 8 cases of manual compression lasting longer than 5 min (maximum 20 min). No major vascular complications were observed, resulting in 100 % procedural success. Minor complications occurred in seven procedures (3.4 %), including two cases of pseudoaneurysms, successfully treated by ultrasound-guided glue injection. The mean {+-} standard deviation score for patients' discomfort was 0.9 {+-} 0.7, whereas the mean score for operators' difficulty was 1.2 {+-} 0.9. In patients with PAOD, the Glubran 2 Seal represents a simple, painless, and efficient vascular closure device, able to achieve hemostasis both in antegrade and retrograde accesses.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Feasibility and Safety of Vascular Closure Devices in an Antegrade Approach to Either the Common Femoral Artery or the Superficial Femoral Artery

Introduction: The purpose of the present study was to analyze complications following antegrade puncture of the common femoral artery (CFA) and the superficial femoral artery (SFA) using vascular closure systems (VCS). Methods: A single-center, retrospective study was performed after obtaining approval from the institutional review board and informed consent from all patients. At our center, the CFA or SFA are used for arterial access. All patients were evaluated clinically on the same day. If there was any suspicion of an access site problem, Duplex ultrasound was performed. Results: Access location was the CFA in 50 patients and the SFA in 130 patients. The sheath size ranged from 4F to 10F. Two patients had to be excluded because of lack of follow-up. Successful hemostasis was achieved in 162 of 178 cases (91 %). The following complications were observed in 16 patients (8.9 %): 4 pseudoaneurysms (2.2 %), 11 hematomas (6.2 %), and 1 vascular occlusion (0.5 %). The two pseudoaneurysms healed spontaneously, in one case an ultrasound-guided thrombin injection was performed, and one aneurysm was compressed manually. No further medical therapy was needed for the hematomas. The one vascular occlusion was treated immediately with angioplasty using a contralateral approach. No significant difference was noted between the CFA and the SFA group with respect to complications (p = 1.000). Conclusions: The use of closure devices for an antegrade approach up to 10F is feasible and safe. No differences in low complication rates were observed between CFA and SFA.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Randomized Trial of the SMART Stent versus Balloon Angioplasty in Long Superficial Femoral Artery Lesions: The SUPER Study

To determine whether primary stenting reduces the rate of restenosis compared with balloon angioplasty alone in the endovascular treatment of long superficial femoral artery lesions; and to assess the effect of treatment on quality of life. A total of 150 patients with superior femoral artery occlusion or severe stenosis of 5-22 cm length from 17 UK centers were randomized to either primary stenting with the SMART stent or balloon angioplasty (i.e., percutaneous transluminal angioplasty, PTA). Bailout stent placement was permitted in case of inadequate result from PTA. The primary end point was restenosis measured by duplex ultrasound at 1 year. Quality-of-life assessments were performed by the EuroQol (EQ)-5D questionnaire. Mean lesion length was 123.0 mm in the stent group and 116.8 mm in the PTA group. A total of 140 (93.3 %) of 150 had total occlusions. At 12 months' follow-up, restenosis measured by Duplex ultrasound was not significantly different between the stent and PTA groups by intention-to-treat or as-treated analyses: 47.2 versus 43.5 % (p = 0.84) and 40.8 versus 46.7 % (p = 0.68), respectively. There were fewer target lesion revascularizations in patients randomized to stenting, but this did not reach statistical significance (12.5 vs. 20.8 %, p = 0.26). There was no difference in the rate of amputation. Patients in both groups reported improved quality of life. Primary stenting of long lesions in predominantly occluded superficial femoral arteries does not reduce the rate of binary restenosis compared with balloon angioplasty and bailout stenting. Both treatment strategies conferred a meaningful and sustained improvement to the quality of life of patients with severe superficial femoral artery disease.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Suitability of Exoseal Vascular Closure Device for Antegrade Femoral Artery Puncture Site Closure

Purpose. To assess the efficacy and safety of the Exoseal vascular closure device for antegrade puncture of the femoral artery. Methods. In a prospective study from February 2011 to January 2012, a total of 93 consecutive patients received a total of 100 interventional procedures via an antegrade puncture of the femoral artery. An Exoseal vascular closure device (6F) was used for closure in all cases. Puncture technique, duration of manual compression, and use of compression bandages were documented. All patients were monitored by vascular ultrasound and color-coded duplex sonography of their respective femoral artery puncture site within 12 to 36 h after angiography to check for vascular complications. Results. In 100 antegrade interventional procedures, the Exoseal vascular closure device was applied successfully for closure of the femoral artery puncture site in 96 cases (96 of 100, 96.0 %). The vascular closure device could not be deployed in one case as a result of kinking of the vascular sheath introducer and in three cases because the bioabsorbable plug was not properly delivered to the extravascular space adjacent to the arterial puncture site, but instead fully removed with the delivery system (4.0 %). Twelve to 36 h after the procedure, vascular ultrasound revealed no complications at the femoral artery puncture site in 93 cases (93.0 %). Minor vascular complications were found in seven cases (7.0 %), with four cases (4.0 %) of pseudoaneurysm and three cases (3.0 %) of significant late bleeding, none of which required surgery. Conclusion. The Exoseal vascular closure device was safely used for antegrade puncture of the femoral artery, with a high rate of procedural success (96.0 %), a low rate of minor vascular complications (7.0 %), and no major adverse events.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

The Preclose Technique in Percutaneous Endovascular Aortic Repair: A Systematic Literature Review and Meta-analysis

Purpose. To establish the efficacy and safety of the preclose technique in total percutaneous endovascular aortic repair (PEVAR).MethodsA systematic literature search of Medline database was conducted for series on PEVAR published between January 1999 and January 2012.ResultsThirty-six articles comprising 2,257 patients and 3,606 arterial accesses were included. Anatomical criteria used to exclude patients from undergoing PEVAR were not uniform across all series. The technical success rate was 94 % per arterial access. Failure was unilateral in the majority (93 %) of the 133 failed PEVAR cases. The groin complication rate in PEVAR was 3.6 %; a minority (1.6 %) of these groin complications required open surgery. The groin complication rate in failed PEVAR cases converted to groin cutdown was 6.1 %. A significantly higher technical success rate was achieved when arterial access was performed via ultrasound guidance. Technical failure rate was significantly higher with larger sheath size ({>=}20F). Conclusion. The preclose technique in PEVAR has a high technical success rate and a low groin complication rate. Technical success tends to increase with ultrasound-guided arterial access and decrease with larger access. When failure occurs, it is unilateral in the majority of cases, and conversion to surgical cutdown does not appear to increase the operative risk.

62 RADIOLOGY AND NUCLEAR MEDICINE↗