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Biomedical subjects

J Fritz Angle

Publications and source records attributed to J Fritz Angle.

15 recordsLinked to original sources
PubMed2005

Magnetic resonance urography for the assessment of potential renal donors: comparison of the RARE technique with a low-dose gadolinium-enhanced magnetic resonance urography technique in the absence of pharmacological and mechanical intervention.

The aim of this study was to determine whether magnetic resonance urography without pharmacological (diuretic) stimulation and mechanical compression allows conclusive evaluation of the urinary system in potential renal donors. In 28 consecutive patients magnetic resonance urography (MRU) was performed on a 1.5-T system. Two techniques, rapid acquisition with relaxation enhancement (RARE) and a gadolinium (Gd)-enhanced 3D fast low angle shot (FLASH) sequence were compared in the absence of adjunctive measures. Two reviewers assessed image quality, presence of artifacts and completeness of visualization of the collecting systems and ureters. Among the 53 MR urograms, there was no difference in image quality and presence of artifacts between RARE and Gd-MRU. Despite high image quality, visualization of the urinary collecting system was insufficient. Continuous visualization from the collecting system to the distal ureter was demonstrated bilaterally in only 14% of the RARE and 26% of Gd-enhanced MR urograms, respectively. Overall, Gd-enhanced MRU was superior to the RARE technique in displaying the segments of the urinary collecting system, but this difference was not found to be statistically significant. Neither the RARE technique nor the gadolinium-enhanced MRU technique is accurate enough to allow the evaluation of the collecting system and ureters in potential renal donors in the absence of pharmacological intervention and compression.

Adult↗
PubMed2005

Placement of transvenous pacemaker and ICD leads across total chronic occlusions.

OBJECTIVE: To establish a method of implantation for device leads across total venous occlusions. BACKGROUND: Indications for pacemaker and implantable cardiac defibrillator implantation continue to expand. Chronic venous occlusions are increasingly encountered with lead placement. Some degree of obstruction can be as high as 13% before device implantation and 50% after transvenous device implantation. We report an approach of venoplasty/dilatation of chronic total occlusions to allow lead placement. METHODS: From January 1, 2002 through December 16, 2004, 1,356 systems (initial and upgrade) were implanted at the University of Virginia. At the time of device implant, seven patients were noted to have chronic venous occlusions and alternative access was precluded. Four of the seven patients had an existing system; the other three received initial implantations. Subsequently, these seven patients had a 5 Fr catheter placed in the basilic/axillary/subclavian vein and a venogram was obtained to demonstrate the area of chronic occlusion. A guide wire was advanced across the lesion for initial recanalization. Dilatation or venoplasty was performed at the occluded site. A guide wire was retained across the lesion and the patient underwent lead implantation. RESULTS: In all seven patients, recanalization was achieved and leads were successfully placed. There were no complications or damage to the vessels or existing leads. CONCLUSIONS: Venoplasty or dilatation of chronic total venous occlusion is a safe and effective technique, which allows for placement of transvenous leads.

Adult↗
PubMed2003

Selection of stents for treating iliac arterial occlusive disease.

Intravascular stents play an increasingly important role in the treatment of iliac artery occlusive disease and their use has expanded the indications for percutaneous endoluminal therapies. The past several years have seen a sharp increase in the number of commercially available covered and uncovered stents. Knowledge of their design and mechanical properties is crucial for selecting the appropriate stent for a particular type of lesion. In this article, the indications for and results of iliac artery stent placement are reviewed and the various characteristics of the currently available stents that may influence operator choice for use in specific lesions are discussed.

Angiography, Digital Subtraction↗
PubMed2003

Simultaneous antegrade and retrograde access for subintimal recanalization of peripheral arterial occlusion.

Subintimal recanalization can be a useful procedure in selected patients with severe peripheral vascular disease with tissue loss or rest pain and limited surgical bypass options. Technical failure occurs in approximately 20% of patient who undergo percutaneous intentional extraluminal recanalization due to inability to reenter the distal true lumen. A technique to improve technical success when performing subintimal recanalization when there is failure to reenter the distal true lumen or possibly when there is a limited segment of patent distal target vessel for reentry is proposed. Further evaluation of this technique is necessary to confirm its safety and determine its technical and clinical success.

Aged↗
PubMed2002

Gadolinium-based contrast agents in angiography and interventional radiology.

Gadolinium is useful as an alternative contrast agent for diagnostic angiographic and interventional procedures in patients with renal insufficiency or a history of a severe reaction to iodinated contrast material. Gadolinium usually is used as a "problem solver" to answer specific diagnostic questions or guide interventional procedures that cannot adequately be defined with CO2 angiography. Because of dose limitations with Gd, careful planning is required prior to its use with angiography or interventional procedures.

Angiography↗
PubMed2002

MR angiography of the renal arteries.

During, the past decade. MRA has evolved from an cxperimental technique into the modality of choice for the noninvasive evaluation of renovascular disease. The recent widespread application of MRA for these indications has been driven primarily by the advent of 3D contrast-enhanced MRA. which provides a fast, reliable technique for imaging large vascular territories and generates images, after postprocessing, similar in appearance to digital subtraction angiography. The cross-sectional volumetric nature of contrast-enhanced MRA affords some advantages over conventional catheter angiography. Although 3D contrast-enhanced MRA forms the backbone of vascular MR studies, several adjunctive sequences are employed to maximize the diagnostic yield of the examination. For example. flow-dependant imaging is used to complement the morphologic images of contrast-enhanced MRA by providing hemodynamic information. As such, MRA is unique among noninvasive imaging modalities in that it offers a comprehensive evaluation of anatomy and function. The availability and reliability of MRA extend renal artery screening to a wider spectrum of patients. Current applications of renal MRA range from detection of renal artery stenosis to evaluation for renal transplant donors.

Humans↗
PubMed2002

MR angiography of the mesenteric vasculature.

MRA has evolved from a research tool to a robust clinical diagnostic modality. In many centers worldwide, it is the technique of choice for evaluating patients with suspected CMI, assessing operability of patients with pancreatic cancer, and investigating the portal system. Evolving indications include the assessment of liver transplant patients before and after transplant and of living related liver transplant donors. The search for the bleeding source in patients with gastrointestinal hemorrhage may be an indication in the future, once intravascular contrast agents become available.

Contrast Media↗
PubMed2002

Body MR venography.

MRV offers unique diagnostic possibilities for detection and characterization of venous disease. It allows evaluation of perivascular and vascular anatomy, evolution of thromboembolic events, and assessment of vascular flow. MRI is a diagnostic tool that can be tailored for a variety of clinical dilemmas, not only DVTs. Continued improvements in hardware and software will expand the role of MRV.

Humans↗
PubMed2002

Percutaneous transluminal angioplasty and stenting in the treatment of chronic mesenteric ischemia: results and longterm followup.

BACKGROUND: The purpose of this study was to review the results of percutaneous transluminal angioplasty (PTA), stenting, or both in the treatment of patients who present with symptoms and angiographic findings most consistent with chronic mesenteric ischemia. STUDY DESIGN: A retrospective analysis of 33 consecutive patients from a single institution who underwent PTA, stenting, or both for treatment of symptoms most characteristic of chronic mesenteric ischemia was performed. RESULTS: There were 12 men and 21 women with a mean age of 63 years (range 40 to 89 years). Median weight loss was 28 lb (range 6 to 80 lb). Postprandial pain was present in 88% of the patients (29 of 33). All lesions treated were stenoses. PTA alone was performed in 21 patients (32 vessels), and PTA and stenting were performed in 12 patients (15 vessels). PTA was technically successful in 26 of 32 vessels (81.3%); PTA plus stenting was technically successful in 15 of 15 vessels (100%) (p = 0.073). Complete alleviation of symptoms occurred immediately in 27 of the patients (82%), and 2 patients (6%) had significant improvement in symptoms. There were four immediate clinical failures (12%): two patients were found to have occult malignancy and one had immediate relief of symptoms after surgical release of the median arcuate ligament. Followup data were obtained in all patients with clinically successful procedures (mean 38 months, median 25 months, range 1 to 123 months). Angiographic followup was available in 52% of the patients (15 of 29), at a mean of 20 months. The primary longterm clinical success rate was 83.3% (24 of 29). Four of the five patients with recurrent symptoms were successfully retreated with endovascular therapy. The primary assisted longterm clinical success rate was 96.6% (28 of 29). The 5-year survival rate was 76.1%. Major complications occurred in 13% of the procedures, with a 30-day mortality rate of 0%. CONCLUSION: Endovascular therapy for treatment of mesenteric arterial stenoses is effective in the treatment of patients with symptoms and angiographic findings characteristic of chronic mesenteric ischemia.

Abdominal Pain↗
PubMed2002

Relative value of analog and digital teaching files.

RATIONALE AND OBJECTIVES: This study was performed to determine if it is financially reasonable for radiology residency programs that create and maintain their own teaching files to switch from analog teaching files (ATFs) to digital teaching files (DTFs). MATERIALS AND METHODS: Radiology residency program directors were surveyed electronically about the monetary value and importance of conventional ATFs and DTFs. The costs for maintaining each type of file were calculated at the authors' institution. RESULTS: Surveys were sent to the program directors of all 197 accredited radiology residencies. Responses were received from 48 (24%). DTFs were scored as more important than ATFs, but the difference was not significant (P = .22). DTFs were rated as less complete (P = .01) but more current (P << .001) than ATFs. DTFs included the American College of Radiology Learning File (85%), in-house productions (77%), and other commercially available products (63%). Thirty percent of respondents had a DTF integrated into a picture archiving and communication system, and 28% reported having a technician dedicated to the teaching file. Program directors ascribed total median dollar values of $250 and $3,000 per year to their ATFs and DTFs, respectively. The annual costs at the authors' institution were much higher than these ascribed values: $44,720 ($91 per case) for maintaining a DTF produced in house and $24,601 ($50 per case) for maintaining an ATF, excluding physician time. CONCLUSION: Program directors are more willing to pay for a DTF than an ATF. For both, the costs of maintenance are great and the relative monetary value is low.

Analog-Digital Conversion↗
PubMedDate not supplied

Percutaneous angioplasty and stenting of left subclavian artery stenosis in patients with left internal mammary-coronary bypass grafts: clinical experience and long-term follow-up.

The authors report their experience with percutaneous transluminal angioplasty (PTA) and stenting of the left subclavian artery (LSA) in patients with recurrent angina and a left internal mammary (LIMA)-coronary bypass graft or in patients who will be undergoing LIMA-coronary artery bypass grafting. From November 1990 to February 2001, 21 patients (11 men and 10 women) with significant left subclavian artery stenosis were treated; 18 patients had a prior LIMA bypass graft, and 3 patients were treated before coronary artery bypass surgery. Angiographic follow-up was performed in 12 patients and clinical follow-up was obtained in all patients. All lesions were atherosclerotic in etiology and located in the proximal left subclavian artery. The mean stenosis was 81% (range 50-100%). All patients initially underwent PTA. Stents were placed in 7 patients for suboptimal PTA results. Technical success was achieved in all patients. Pressure gradient measurements were available in 6 patients. Mean pretreatment gradient was 29 mm Hg (range, 10-50 mm Hg) and fell to 3 mm Hg (0-8 mm Hg) posttreatment. There were 2 minor and 2 major complications. The 30-day mortality rate was 9.5% (2 patients). The remaining 19 patients had clinical or angiographic follow-up of 4-68 months (mean, 27 months). Three patients were found to have recurrent stenoses by angiography 8-43 months after PTA and 3 more had clinical signs of recurrent stenosis. Therefore, the long-term clinical patency rate of LSA PTA and stent was 15 of 19 (79%). One was managed with bypass surgery, 1 with repeat PTA and stent placement, and 1 was managed conservatively. Therefore, the assisted patency was 15 of 19 (79%). Eleven of 19 (58%) of the patients in long-term follow-up had cardiac symptoms, but repeat angiography excluded recurrent LSA stenosis as the cause of their symptoms in 7 cases. Only 4/19 (21%) had cardiac symptoms potentially attributable to LSA restenosis. Four patients expired during follow-up, but 3 had no evidence of subclavian stenosis. PTA and stenting is an effective treatment of proximal left subclavian artery stenosis in patients who develop angina after a LIMA-coronary artery bypass, or in patients before a LIMA-CABG. Cardiac symptoms after LSA PTA and stent are most often due to progressive coronary artery disease rather than to recurrent LSA stenosis.

Adult↗