PubMed Health⌕ Search

Biomedical subjects

Edward B Diethrich

Publications and source records attributed to Edward B Diethrich.

At least 19 recordsLinked to original sources
PubMed2007

Introduction to thoracic endografting: imaging, guidewires, guiding catheters, and delivery sheaths.

PURPOSE: With the recent approval of the first thoracic endoprosthesis in the United States for the treatment of isolated descending thoracic aortic aneurysms, there has been a dramatic increase in the number of physicians interested in getting involved in this emerging technology. However, many of these physicians do not have extensive endovascular experience, are not familiar with the catheters and guidewires used for thoracic endografting procedures, or do not have access to a full complement of endovascular resources. DESCRIPTION: We discuss the basics of catheters, guidewires, and balloons necessary to perform thoracic endovascular procedures. EVALUATION: Adequate radiographic visualization of the thoracic aorta and access vessels is essential for all phases of the thoracic endografting procedure. In addition, a vast array of catheters, guidewires, balloons, and sheaths have been designed to assist with endovascular access and delivery of various therapeutic modalities. CONCLUSIONS: Each of the different catheters and guidewires serve an important purpose in the conduct of thoracic endografting procedures, and it is important to have a full understanding of these devices to ensure the best results.

Adult↗
PubMed2006

A percutaneous swine model of myocardial infarction.

INTRODUCTION: The aim of this study was to develop a percutaneous, low risk, and reproducible technique of MI that simulates human disease. METHODS: MI was induced in 44 swine (32.8+/-7.2 kg) by percutaneous embolization coil deployment in the left anterior descending coronary artery. Hemodynamic measurements, left heart catheterization, and echocardiography were performed pre, post, and 30 days after MI. 3D NOGA viability mapping was performed at baseline and 30 days. Excised hearts were examined histologically. RESULTS: Pre-MI mortality was 6.8% and 24 h mortality was 13.6%. All pigs that survived 24 h after MI remained alive at 30 days. The mean left ventricular ejection fraction decreased from 58.4% to 42.1% (p<0.001) at 30 days. The average thrombolysis in myocardial infarction score was 3, 0, and 1.5 at baseline, post-MI, and 30 days, respectively. At 30 days, the end diastolic diameter, end diastolic volume, end systolic volume, and wall motion index increased from 3.76 to 3.89 cm, 32.5 to 50.0 ml, 14.9 to 27.0 ml, and 1.01 to 1.38, respectively (all p<0.05), while the ejection fraction decreased from 56.5% to 49.4% (p<0.01). Additionally, at 30 days, statistically significant reductions in both unipolar and bipolar voltage in the mid and apical regions of the left ventricle were observed. Postmortem pathology showed a transmural scar in the apical anteroseptal regions with fibrosis in the MI region, which accounted for 14.8% and 14.2% of the total left and right ventricular myocardial area and volume, respectively. DISCUSSION: This model of MI is reliable, reproducible, has a pathophysiology similar to humans, and a lower mortality and ventricular fibrillation rates compared to other models. This model may be used to evaluate the effects of pharmacologics, gene therapy, and stem cell transplantation for the treatment of cardiovascular disease as well as studying mechanisms of cardiac remodeling.

Angiography↗
PubMed2006

Safety and feasibility of percutaneous autologous skeletal myoblast transplantation in the coil-infarcted swine myocardium.

INTRODUCTION: Autologous skeletal myoblast transplantation (ASMT) for myocardial regeneration is a promising new treatment for patients with congestive heart failure secondary to myocardial infarction (MI). However, non-surgical delivery could broaden the utility of this approach. The present study was designed to evaluate the safety and feasibility of transplanting autologous skeletal myoblast (ASM) via endovascular delivery into the infarcted swine myocardium. METHODS: Seven female Yorkshire swine successfully underwent induced left ventricular MI. ASM biopsies were obtained from the hind limb of each animal and myoblasts were expanded in vitro. In a pilot experiment, ASM were labeled with iridium and short-term retention and biodistribution was determined 2 h after ASM delivery via the MyoStar needle-injection catheter inserted through the femoral artery. At 30 days post-infarction, the remaining animals were divided into three groups containing 2 animals each for percutaneous catheter delivery into the infarcted zone: group 1 control animals were injected with media only, group 2 and 3 animals were injected with approximately 300 x 10(6) and 600 x 10(6) ASM, respectively. Sixty days post-transplantation, the swine hearts were harvested. RESULTS: During the 60-day period between transplantation and harvest, no adverse events were recorded, and continuous rhythm monitoring revealed no arrhythmias. In the small sampling size, myocardial function assessments revealed a trend toward improvement in the treatment groups with respect to ejection fraction, viability, and cardiac index. However, histology of treated swine hearts identified no skeletal muscle cells. DISCUSSION: Percutaneous ASMT into an infarcted swine myocardium is feasible and safe, and may contribute to overall improved heart function.

Animals↗
PubMed2006

A randomized, double-blind, placebo-controlled, multicenter, pilot study of the safety and feasibility of catheter-based intramyocardial injection of AdVEGF121 in patients with refractory advanced coronary artery disease.

BACKGROUND: The experience with direct myocardial injection of adenovirus encoding angiogenic growth factor is limited to invasive surgical approach. Accordingly, we sought to evaluate, for the first time, in a randomized, double-blind, placebo-controlled, phase I pilot study the safety and feasibility of percutaneous catheter-based intramyocardial delivery of a replication-deficient adenovector encoding the 121-amino-acid isoform of vascular endothelial growth factor (AdVEGF121). METHODS: Ten "no-option" patients with severe coronary artery disease were randomized (2:1) to receive AdVEGF121 (4 x 10(10) pu) or placebo as fifteen 100 microL, evenly distributed, endomyocardial injections using a nonflouroscopic, 3-dimensional mapping and injection (NOGA) catheter-based system. RESULTS: Injection procedure was successfully completed in all cases and was associated with no major adverse events. AdVEGF121 was considered potentially associated with a single serious adverse event of transient moderate fever. Elevated postprocedure CK and CK-MB fraction levels were recorded in two placebo-treated and three AdVEGF121-treated patients; all CK measured values were <1.5 times upper limit of normal. All adenoviral cultures (urine and throat swab) were negative 24-hr after dosing, and no significant changes in serial plasma VEGF levels were noted over time. At 12 months follow-up, no cancers, proliferative retinal changes, or significant abnormalities in hepatic, renal or hematological indices were observed. CONCLUSIONS: Percutaneous, catheter-based AdVEGF121 intramyocardial injection is a practical, feasible, and potentially safe approach for intramyocardial gene transfer. A larger randomized, phase II efficacy study is warranted.

Adult↗
PubMed2006

Midterm outcome in 158 consecutive Gore TAG thoracic endoprostheses: single center experience.

BACKGROUND: Despite recent improvements in surgical technique, some patients with descending thoracic aortic pathologies are unable to undergo open surgical repair due to significant comorbidities and/or unfavorable thoracic aortic anatomy. Some of these patients might be able to tolerate a less invasive approach, such as endoluminal grafting. We reviewed our consecutive clinical experience with the Gore TAG endoprosthesis (W. L. Gore & Assoc, Flagstaff, AZ) for the endovascular exclusion of assorted descending thoracic aortic pathologies in higher surgical risk patients. METHODS: After obtaining institutional review board approval, 158 high surgical risk patients underwent attempted delivery of a Gore TAG thoracic endoprosthesis between February 2000 and July 2004. Indications for study enrollment were atherosclerotic aneurysm (n = 76), aortic dissection (n = 36), penetrating aortic ulcer (n = 15), contained rupture (n = 11), pseudoaneurysm (n = 10), traumatic aortic injury (n = 5), aortobronchial fistula (n = 4), and aortic coarctation (n = 1). RESULTS: The device was successfully delivered in 156 (98.7%) patients. Mean patient age was 72 +/- 12.1 years. Three (1.9%) patients developed transient paraparesis after graft deployment and 1 (0.6%) patient developed paraplegia. While postimplantation endoleaks were observed in 18 (11.5%) patients, only 12 patients required reintervention. Thirty-day mortality was 3.8% (6 of 156). Mean follow-up was 21.5 +/- 18.8 months, and the overall mortality was 17.3% (27 of 156). CONCLUSIONS: Endoluminal grafting of multiple types of descending thoracic aorta pathologies with the Gore TAG thoracic endoprosthesis is feasible and safe in higher surgical risk patients. Additional studies and long-term follow-up of these patients are warranted.

Aged↗
PubMed2006

Are penetrating aortic ulcers best treated using an endovascular approach?

BACKGROUND: Optimal treatment for penetrating aortic ulcers has yet to be determined. Although open surgical repair is an effective therapeutic option, less invasive alternatives such as endoluminal grafting are emerging as a potential adjunct for the treatment of penetrating aortic ulcers isolated to the descending thoracic aorta. We reviewed our cumulative experience with thoracic endografting for penetrating aortic ulcers of the descending thoracic aorta. METHODS: Between March 2003 and September 2005, 21 patients with penetrating aortic ulcers of the descending thoracic aorta were treated with Gore TAG thoracic endoluminal stent-grafts as part of a single-center investigational device exemption protocol. RESULTS: Mean patient age was 73 +/- 12 years, and 7 (33%) of 21 were men and 14 (67%) were women. Patients presented with both acute (<14 days; 16/21, 76.2%) and chronic symptoms (5/21, 23.8%). The endoluminal stent-graft was successfully delivered in all 21 patients. No endoleaks were detected at 30-days postprocedurally or in follow-up (mean follow-up, 14 +/- 18 months). The 30-day mortality was 0%, and overall mortality was 4.8% (1/21), which was unrelated to the endovascular intervention. CONCLUSIONS: Endovascular therapy for penetrating aortic ulcers of the descending thoracic aorta is safe and feasible. The number of patients diagnosed with penetrating aortic ulcers is expected to increase as improved imaging systems are becoming more commonplace. As a result, new and safer treatment paradigms will become even more important in the treatment of aortic diseases. Compared with historical surgical results, endovascular therapy for penetrating aortic ulcers of the descending thoracic aorta appears to have less operative mortality and is as equally effective as open surgical repair. Long-term surveillance and continued investigation are warranted.

Adult↗
PubMed2006

Virtual histology and color flow intravascular ultrasound in peripheral interventions.

The quality and interpretation of intravascular ultrasound (IVUS) imaging has been revolutionized in recent years by two new and major advances: virtual histology and color flow IVUS. Virtual histology intravascular ultrasound (VHIVUS) is a catheter-based technology where IVUS is generated from the transducer on the catheter tip and the reflected signals from the artery wall produce a color-coded map of the arterial disease. Different histological constituents of the plaque produce different reflected signals and these are assigned different colors (dark green, fibrous; yellow/green, fibrofatty; white, calcified; red, necrotic lipid core plaque). This color-coded map assists the interventionalist in understanding more fully how the lesion will behave at the moment of treatment, whether it will resist complete stent deployment or be liable to embolization. Originally introduced for coronary interventions, VHIVUS is now being applied to peripheral situations. Because it provides a detailed and close-proximity view of plaque, its potential to improve the safety and efficacy of carotid endoluminal repair is stimulating substantial interest. Similarly, color flow IVUS provides greater understanding for the operator of blood flow, and the interface between the vessel wall and the blood stream, lumen size, and success of treatment. Color flow IVUS does not use the Doppler effect, but creates real-time images that resemble color flow Doppler ultrasound. These two technological advances in IVUS have greatly improved the ability of the endovascular specialist to understand the arterial disease they are treating and to assess the completion of treatment.

Blood Vessel Prosthesis Implantation↗
PubMed2006

Endovenous ablation of incompetent saphenous veins: a large single-center experience.

PURPOSE: To evaluate the effectiveness of endovenous treatment of symptomatic varicose veins using the endovenous laser (EVL) or radiofrequency (RF) energy over a >3-year follow-up. METHODS: From February 2002 to August 2005, 981 consecutive patients (770 women; mean age 51 years, range 15-90) with symptomatic varicose veins in 1250 lower limbs underwent endovenous ablation of 1149 great saphenous veins (GSV) and 101 small saphenous veins (SSV) under tumescent anesthesia without intravenous sedation or regional anesthesia. There were 990 GSV and 101 SSV procedures using EVL; 159 GSVs were treated with RF energy. An ultrasound evaluation was performed within 2 weeks of the procedure to evaluate occlusion of the vein, wall thickness, and clot extension into the deep venous system. Follow-up from the first 200 procedures in the series included clinical evaluation and duplex ultrasound scanning at 6 and 12 months and annually thereafter. RESULTS: Of the 1149 GSVs treated, 39 (3.4%) recanalizations were seen in 33 of the EVL and 6 of the RF procedures for inadequate treatment as judged by ultrasound. There were 9 (9.0%) failures among the 101 SSVs treated with EVL. Overall, both EVL and RF procedures were well tolerated, with only minor complications. One obese patient with ulcer developed pulmonary embolus on the fourth postoperative day. There were no differences between EVL and RF in efficacy or complications. Follow-up at a mean 3 years (range 30- 42 months) in 143 treated limbs showed no neovascularization in the groin. CONCLUSION: Outcomes with EVL and RF were good, with low complication rates that may be related to the use of local tumescent anesthesia without intravenous sedation.

Adolescent↗
PubMed2006

Endovascular approaches for complex forms of recurrent aortic coarctation.

PURPOSE: To review a single-center experience with endovascular treatment of recurrent aortic coarctation in adults. METHODS: Since 1998, 11 patients (9 men; mean age 48+/-15 years, range 16-63) with recurrent aortic coarctation following previous coarctation repair were referred to our institution for treatment. Clinical presentations included pseudoaneurysm (n=2), restenosis (n=3), pseudoaneurysm accompanied by restenosis (n=4), and rupture of a post-coarctation pseudoaneurysm (n=2). All patients were treated using an endovascular approach as part of a single-center investigational device exemption protocol. RESULTS: Endovascular interventions included Palmaz stent implantation (n=3), implantation of an endoluminal graft (n=2), or a combination of both treatments in 6 patients. Three patients underwent balloon angioplasty before stenting or endografting, and 2 patients had a carotid-subclavian bypass done before the endovascular repair. All repairs were technically and clinically successful. The median length of stay after repair was 2.0+/-2.3 days. In follow-up, 2 patients underwent a carotid-subclavian bypass for left upper extremity claudication. Two patients required reintervention owing to migration of the stent in 1 and an endoleak 2 years after the initial procedure in the other. CONCLUSION: Endovascular approaches to adult coarctation appear to be safe and effective. With the emergence of endoluminal grafts and the widespread availability of the Palmaz stent, endovascular repair offers an excellent alternative to open surgery for complex cases of recurrent coarctation. Additional studies are indicated to assess the long-term outcomes of these patients.

Adolescent↗
PubMed2006

Gore TAG Thoracic Endoprosthesis: the first US FDA-approved thoracic endograft.

Open surgical repair of thoracic aortic lesions carries a significant risk of complications, including death. Minimally invasive approaches, however, may improve outcomes. Clinical trials of the Gore TAG Thoracic Endoprosthesis device indicate that subjects receiving the graft are less likely to experience major adverse events, less intraprocedural blood loss, shorter intensive care unit and hospital stays, and reduced recovery times than surgical patients. The US FDA approved the device in March 2005. Since then, the device has been used widely, although a 0.30% rate of complications related to infolding or partial compression of the device prompted a 'Dear Doctor' letter in January 2006. This article profiles the TAG device and evaluates endografting technology in general.

Aorta, Thoracic↗
PubMed2005

Endoluminal stent-graft stabilization for thoracic aortic dissection.

PURPOSE: To review our experience with thoracic endografting for type B aortic dissection using the TAG Endoprosthesis. METHODS: A retrospective analysis was performed of data collected prospectively from March 2000 to July 2004 under an investigational device exemption protocol for the TAG thoracic endograft. In this time period, 40 patients (29 women; mean age 67 years, range 39-91) were treated with this endograft for type B aortic dissection. RESULTS: Technical success was 95%. There was 1 (2.5%) perioperative death, and 1 (3%) endoleak was treated with an additional graft on postoperative day 2. Fifteen (38%) patients experienced postoperative complications, mainly renal or pulmonary, and 1 (3%) patient developed postoperative paraplegia that did not resolve. The 1-year survival was 85%. Follow-up computed tomography was available for 31 patients with an average 15-month follow-up. There was no significant change in size of the thoracic aorta in 22 patients; 8 aneurysmal segments were significantly reduced in size and 1 thoracic aortic aneurysm expanded. No thoracic aortic ruptures were seen in this series. CONCLUSIONS: These early results indicate type B thoracic aortic dissections can be treated with acceptable morbidity and mortality using endografts. Stent-graft repair of the thoracic aorta may decrease the incidence of thoracic aortic expansion and rupture.

Adult↗
PubMed2005

Great vessel transposition for antegrade delivery of the TAG endoprosthesis in the proximal aortic arch.

PURPOSE: To report a technique for antegrade delivery of the TAG stent-graft during repair of lesions in the proximal aortic arch. TECHNIQUE: Via an 8-cm median sternotomy, a bifurcated graft, usually 14 or 16 mm in diameter, is anastomosed to the ascending aorta with 4-0 Prolene suture; a 10-mm straight graft is cut obliquely and anastomosed to the heel of the bifurcated graft for delivery of the endograft antegrade across the aortic arch. The great vessels in turn are clamped, transected at the arch, and sutured to the bypass graft. A 9-F sheath is secured in the conduit, and a 250-cm angled hydrophilic guidewire is passed to the desired iliac artery and exteriorized through the femoral sheath. The conduit is clamped, and the TAG's delivery sheath is substituted for the 9-F sheath. A marker is placed on the conduit to assure that the stent-graft is deployed just beyond the limb origins of the bifurcated graft. The conduit is introduced across the aortic arch, followed by the endograft, which is positioned at the marker as the sheath is withdrawn into the conduit. After completion angiography, the delivery sheath is removed, and the conduit is transected and oversewn. Heparinization is reversed, and the incision is closed, with one mediastinal drainage tube in place. CONCLUSIONS: This technique allows precise delivery of the endoluminal graft at the proximal aortic arch, thus avoiding problems with retrograde delivery.

Anastomosis, Surgical↗