Faculty Bibliography
Searched for:
in-biosketch:true
person:sadekm01
Total Results:
107
Five-year results for the Talent enhanced Low Profile System abdominal stent graft pivotal trial including early and long-term safety and efficacy
OBJECTIVES: The pivotal trial of the Talent enhanced Low Profile System (eLPS; Medtronic Vascular, Santa Rosa, Calif) stent graft evaluated short and long-term safety and efficacy of endovascular aneurysm repair (EVAR). These data and a confirmatory group assessing the performance of the CoilTrac delivery system supported the United States premarket approval application for the device. METHODS: The pivotal trial was a prospective, nonrandomized study conducted at 13 sites from February 2002 to April 2003. The study group (n = 166) underwent EVAR using the Talent eLPS stent graft. The control group (n = 243) underwent open surgical AAA repair. Data for this group were obtained from the Society for Vascular Surgery Endovascular AAA Surgical Controls project. Outcomes were compared at 30 days and 12 months. Additional 5-year follow-up was obtained for the eLPS group. A single-center cohort of 137 patients was the confirmatory group for the assessment of the clinical performance of the CoilTrac delivery system, with analysis of outcomes
PMID: 20206803
ISSN: 0741-5214
CID: 379462
Safety and efficacy of carotid angioplasty and stenting for radiation-associated carotid artery stenosis
INTRODUCTION: Prior neck irradiation may induce atherosclerosis in the carotid artery and is considered an indication for carotid angioplasty and stenting (CAS). This study sought to evaluate the effect of neck radiation therapy (XRT) on the rate of restenosis and embolic potential in patients undergoing CAS. METHODS: Two hundred ten CAS procedures were performed on 193 patients (XRT [N = 28], non-XRT [N = 182]). Mean follow-up was 347 +/- 339 days (median, 305 days; range, 16-1354 days). Duplex velocity criteria for restenosis after CAS were: >50% restenosis (peak systolic velocity [PSV] > 125 cm/sec, end diastolic velocity [EDV] 40-99 cm/sec, and internal carotid artery to common carotid artery systolic ratio [ICA/CCA] > 2.0); >70% restenosis (PSV>230 cm/sec, EDV>100 cm/sec, and ICA/CCA ratio >4.0). Restenosis >70% was confirmed by digital subtraction angiography. Additional endpoints included groin hematoma, groin pseudoaneurysm, myocardial infarction, stroke, mortality, and the combined myocardial infarction/stroke/mortality rate. Captured particulate data was obtained from microporous filters used during CAS. Nineteen XRT and 128 non-XRT consecutive filters were analyzed. Photomicroscopy was performed along three axes for each filter, and the quantity and size of the captured particles were analyzed using video image analysis software. RESULTS: There were more men (XRT: 85.7% vs. non-XRT: 52.8%, P < .001) and prior surgical neck dissections in the XRT patients (XRT: 82.1% vs. non-XRT: 4.7%, P < .001). Pre-procedural stenosis did not differ significantly betweeen the two groups (XRT: 86.5% +/- 8.9% [range, 70%-99%] vs. non-XRT: 85.5% +/- 8.7% [range 70%-99%], P = NS). Perioperative outcomes, including the composite 30 day stroke/myocardial infarction/mortality rate did not differ significantly between the two groups (XRT: 0% vs. non-XRT: 3.2%, P = NS). Twelve-month freedom from restenosis rates did not differ significantly at the 50% threshold (XRT: 95.5% vs. non-XRT: 90.3%, P = NS) or at the 70% threshold (XRT: 95.5% vs. non-XRT: 96.5%, P = NS). Target lesion revascularization did not differ significantly (XRT: 0% vs. non-XRT: 0.5%, P = NS). Photomicroscopy demonstrated a trend towards increased particle number and size in the XRT filters, however the results did not achieve statistical significance: particle number (XRT: 9.8 +/- 8.4 vs. non-XRT: 9.6 +/- 11.7, P = NS), %patients with particle size >1000 microm (XRT: 47.4% vs. non-XRT: 30.5%, P = NS). CONCLUSIONS: This study suggests that the durability of CAS and the characteristics of captured embolic particles are not altered by a history of neck XRT. This supports the safety and efficacy of CAS for the treatment of patients with a history of neck XRT. Prior neck XRT may predispose the patient to the de novo development of stenoses at locations that were not previously treated
PMID: 19703754
ISSN: 1097-6809
CID: 105644
Improved outcomes are associated with multilevel endovascular intervention involving the tibial vessels compared with isolated tibial intervention
OBJECTIVE: Endovascular intervention is increasingly accepted as an alternative to surgery for the treatment of tibial vessel disease. Tibial vessel disease can occur in isolation or in conjunction with disease that involves the proximal lower extremity vasculature (multilevel disease). This study evaluated the overall efficacy of endovascular intervention for tibial vessel disease and whether the requirement for single-level compared with multilevel intervention affected outcomes. METHODS: This study evaluated a consecutive unselected group of patients who underwent an infrapopliteal intervention from November 2002 to February 2008. The primary end points evaluated were technical success, limb salvage, primary patency, and secondary patency. The secondary end points evaluated were 30-day access site (ie, hematoma, pseudoaneurysm, and wound infection), intervention site (ie, thrombosis), and systemic (ie, acute renal failure, myocardial infarction, and mortality) complications. Patency and limb salvage were evaluated using Kaplan-Meier life-table analyses and compared using Cox regression analysis. P < .05 was considered statistically significant. RESULTS: The study comprised 85 patients, 89 limbs, and 114 procedures. Age was 72.4 +/- 13.1 years, 67% were men, and follow-up was 245.8 +/- 290.8 days. The technical success rate for all procedures was 91%. Limb salvage rates for patients with critical limb ischemia at 6, 12 and 18 months were 85% +/- 0%, 81% +/- 0%, and 69% +/- 0%, respectively. For the complete patient cohort, primary patency rates at 6, 12 and 18 months were 68% +/- 6%, 50% +/- 8%, and 37% +/- 9%, respectively, and secondary patency rates were 81% +/- 5%, 71% +/- 7%, and 63% +/- 8%. Multilevel intervention was associated with significantly improved secondary patency compared with single-level intervention (P = .045). CONCLUSIONS: Patency and limb salvage rates for endovascular treatment of tibial vessel disease in this study are comparable with prior reports and with historical surgical controls. Patients who undergo multilevel intervention involving the tibial vessels exhibit improved secondary patency compared with those who undergo intervention for lesions isolated to the tibial vessels. This may reflect increased distal disease burden for patients who undergo isolated tibial intervention. The study data suggest that the presence of multilevel disease should not preclude an attempt at percutaneous revascularization. Further study is required before formulating definitive recommendations for the endovascular treatment of tibial vessel disease.
PMID: 19268768
ISSN: 0741-5214
CID: 379472
Matrix metalloproteinases in critical limb ischemia
Critical limb ischemia (CLI) is most commonly the result of arterial occlusive disease, specifically atherosclerotic plaque formation and rupture within the infrainguinal arteries. The physiological response to CLI is partial limb reperfusion via the distinct processes of angiogenesis and arteriogenesis. Matrix metalloproteinases (MMPs) are extracellular matrix-remodeling enzymes that play an important role in both the occlusion and reperfusion processes associated with CLI. This article provides a review of the recent literature, summarizing the current understanding of the role of MMPs in both the arterial occlusion and limb reperfusion associated with CLI. Specifically, the functions of MMPs in atherosclerosis, angiogenesis, and arteriogenesis are discussed
PMID: 18155249
ISSN: 1095-8673
CID: 84015
Gene expression analysis of a porcine native abdominal aortic aneurysm model
INTRODUCTION: We sought to characterize the gene expression patterns occurring during the development of aneurysms in the native porcine aorta. METHODS: In Yorkshire swine, the infrarenal aorta was balloon dilated and infused with a solution of type I collagenase/pancreatic porcine elastase (16,000 U/1,000 U). Aneurysmal and control aortic samples were obtained at 1 (n = 3), 2 (n = 6), and 4 (n = 5) weeks following aneurysm induction. RNA was isolated, converted to biotin-modified antisense RNA and hybridized to porcine genome arrays. Aneurysmal and control gene intensities were compared using the 2-sample-for-means z-test. P < .01 was considered statistically significant. RESULTS: Extracellular matrix remodeling genes that were upregulated in aneurysmal compared with control tissue included matrix metalloproteinase-1, -2, -3, and -9; MT-MMP; cathepsin-D, -H, -K, and -S; tissue inhibitor of metalloproteinase-1; and collagen I-alpha1 chain (P < .01). Elastin exhibited temporally downregulated gene expression (P < .01). Inflammatory genes that were upregulated included intercellular adhesion molecule-2, tumor necrosis factor-alpha, interleukin (IL)-1 beta, IL-10, chemokine receptor-4, and tissue plasminogen activator (P < .01). Atherosclerosis and cancer genes that were upregulated included apolipoprotein E, acyl-CoA binding protein, friend leukemia virus integration-1, and E26 transformation-specific sequence (P < .01). CONCLUSION: The porcine model replicates the gene expression patterns that are observed during the development of aneurysms in human studies as well as in rodent models. The porcine model thereby represents a novel method to study the impact of endovascular, cell-based, and other therapeutic interventions on AAA pathophysiology.
PMCID:2580720
PMID: 18656633
ISSN: 0039-6060
CID: 379482
Carotid angioplasty and stenting, success relies on appropriate patient selection
OBJECTIVE: Carotid angioplasty and stenting (CAS) is a percutaneous alternative to carotid endarterectomy (CEA) for treating patients with carotid artery stenosis. This study sought to evaluate whether patients at increased perioperative risk for CEA may be treated with CAS while maintaining equivalent outcomes. METHODS: This study was a nonblinded, retrospective analysis of data obtained from September 2002 to present in the CAS group and from January 1997 to present in the CEA group. Two hundred thirty-one CAS and 647 CEA procedures were performed. Patients were selected for CAS based on criteria that placed them at increased risk for standard CEA surgery. Except for percentage women treated, baseline demographics did not differ between patients treated with CAS and CEA: mean age (72.0 years [range 46-94] vs 70.5 years [range 42-92], P = NS), mean follow-up (12.8 +/- 11.8 months vs 8.7 +/- 10.0 months, P = NS) and percentage women treated (41.4% vs 32.3%, P = .03). Cerebral protection devices were used in 228/231 patients treated with CAS, and each patient underwent an NIH Stroke Scale assessment 24 hours postoperatively and at 30 days follow-up by an independent observer. RESULTS: Preoperative neurologic symptoms did not differ between patients treated with CAS and CEA: amaurosis fugax (6.06% vs 6.96%, P = NS), transient ischemic attacks (13.4% vs 13.9%, P = NS), strokes (19.9% vs 14.1%, P = NS) and total symptoms (27.7% vs 30.5%, P = NS). Due to the selection of patient groups based on predefined clinical characteristics, factors associated with an increased risk of complications from standard CEA surgery were generally more prevalent in patients treated with CAS: neck irradiation (6.06% vs 1.24%, P < .001), neck dissection for cancer therapy (7.8% vs 1.5%, P < .001), prior ipsilateral CEA (15.2% vs 3.4%, P
PMID: 18455640
ISSN: 0741-5214
CID: 379492
Evaluation of pressure transmission and intra-aneurysmal contents after endovascular repair using the Trivascular Enovus expanded polytetrafluoroethylene stent graft in a canine model of abdominal aortic aneurysm
OBJECTIVE: Endotension has been defined as persistently increased pressure within the excluded sac of an abdominal aortic aneurysm (AAA) resulting in increasing aneurysm size after endovascular repair in the absence of endoleak. Devices that use expanded polytetrafluoroethylene (ePTFE) have been associated with the development of endotension and continued AAA enlargement. In this study, intra-aneurysmal pressure and aneurysm content were evaluated after endovascular repair with the Enovus ePTFE stent graft in a canine model. METHODS: Prosthetic ePTFE aneurysms, each containing a solid-state, strain-gauge pressure transducer, were implanted in the infrarenal aorta of 13 mongrel dogs (25-35 kg). A second pressure transducer was inserted into the native aorta for systemic arterial pressure measurement. The stent graft was then deployed to exclude the aneurysm via distal aortic access. Comparison was made among three distinct stent grafts: the Trivascular Enovus (nonporous ePTFE; four animals), the original Gore Excluder (porous ePTFE; five animals), and the Medtronic AneuRx (Dacron; four animals). Daily systemic and intra-AAA pressures were measured for 4 weeks. Intra-aneurysmal pressures were indexed to simultaneously measured systemic pressures. After 4 weeks, the aorta, the prosthetic aneurysm, and its contents were harvested, photographed, and processed for histologic investigation with hematoxylin and eosin and Masson trichrome staining. RESULTS: Within 24 hours after exclusion, the mean arterial pressure and pulse pressure within the AAA sac tapered to less than 20% of systemic pressure for all three stent graft types. Throughout the postoperative period, significantly lower indexed intra-aneurysmal pressures were present in the Enovus- and AneuRx-treated aneurysms as compared with those treated with the original Excluder stent graft (0.05 +/- 0.04, 0.16 +/- 0.06, and 0.06 +/- 0.03 for the Enovus, Excluder, and AneuRx, respectively). Histologic analysis of the Enovus-treated aneurysms demonstrated intraluminal content characterized almost entirely by erythrocytes and infrequent white blood cells without the fibrin organization-characteristics of acute or chronic thrombus. This contrasted with the content of the Excluder-treated aneurysms, which contained poorly organized fibrin deposition suggestive of acute thrombus, and of the AneuRx-treated aneurysms, which demonstrated mature, well-organized collagenous connective tissue. CONCLUSIONS: Exclusion of the AAA with the Enovus stent graft resulted in nearly complete elimination of intra-aneurysmal pressure in this model. Histologic analysis of the aneurysm content further suggested complete exclusion, including elimination of circulating clotting factors and fibroblasts responsible for thrombus formation and reorganization. Ultimately, clinical evaluation will be necessary to demonstrate the effectiveness of this stent graft in preventing the development of endotension.
PMID: 17905556
ISSN: 0741-5214
CID: 379502
