Biomedical subjects

James R Wilentz

Publications and source records attributed to James R Wilentz.

8 recordsLinked to original sources

PubMed2004

Endovascular treatment of the subclavian artery: stent implantation with or without predilatation.

The endovascular treatment of subclavian artery (SA) lesions is less invasive than open surgical repair, with a low rate of complications. We report our experience in 89 subclavian obstructive lesions (n = 86) treated with stenting: 76 (85.3%) stenoses and 13 (14.6%) total occlusions. The left side was most frequently involved (83.1%), localized at the prevertebral segment in 91%. Technical success was obtained in 83 (93.3%) cases, 100% in stenotic lesions and 53.8% in total occlusions. There were nine global complications (10.1%): five (5.6%) at site of puncture, two distal embolization (2.2%), and two (2.3%) major events. The long-term follow-up was 3.51 +/- 1.98 years, during which time 13 (16.8%) restenoses and 2 (2.6%) reocclusions were noted. Subgroup analysis of patients with stenting after predilatation versus direct stenting technique showed in-hospital complications only in the first group, with a restenosis rate of 28.5% vs. 4.7%, respectively (P = 0.003). We consider stenting for SA obstructive lesions the first therapeutic option.

Aged↗

PubMed2004

Molecular and cellular basis of restenosis after percutaneous coronary intervention: the intertwining roles of platelets, leukocytes, and the coagulation-fibrinolysis system.

The major limitation of percutaneous coronary intervention (PCI) is restenosis. Restenosis is considered to be an overreaction of the natural healing process after traumatic balloon dilatation. An elaborate web of cellular and molecular responses, including the interaction of platelets, leukocytes, and the coagulation-fibrinolysis system, as well as the secretion of various growth factors and pro-inflammatory cytokines, contributes to neointimal hyperplasia and the development of restenosis. Moreover, platelet and neutrophil activation after stenting appears to be different from that after balloon angioplasty alone. Pharmacotherapy targeting the cell-to-cell interaction between platelets and neutrophils may potentially offer an effective treatment strategy against restenosis after PCI.

Angioplasty, Balloon, Coronary↗

PubMed2004

Establishing a new target range for unfractionated heparin for acute coronary syndromes.

INTRODUCTION: The target activated partial thromboplastin time (aPTT) range of 1.5 to 2.5 times the control value or 45 to 75 seconds recommended by the ACC/AHA for patients receiving unfractionated heparin (UFH) for acute coronary syndromes (ACS) is vulnerable to variation in test reagents. Rather than use the standard target aPTT range, it has been recommended that each institution establish its own target aPTT range based upon anti-factor Xa heparin levels. As a quality assurance project, we evaluated our institution's therapeutic aPTT range by examining the correlation between aPTTs and anti-factor Xa heparin levels and established a new target aPTT range with a new thromboplastin reagent based upon the therapeutic anti-factor Xa heparin levels. METHODS: Sixty-two plasma samples from 26 consecutive patients receiving UFH for ACS were analyzed. Plasma aPTTs measured with a thromboplastin reagent and a new thromboplastin reagent and anti-factor Xa heparin levels were obtained on each plasma sample. Linear regression analysis was performed to establish a new target aPTT range from corresponding therapeutic anti-factor Xa heparin levels. RESULTS: Thirty-two percent of patients with our institution's target range aPTTs of 61 to 100 seconds had anti-factor Xa heparin levels below 0.35 to 0.7 U/mL while 68% of patients had therapeutic anti-factor Xa heparin levels (positive predictive value = 68%). When the same blood was tested with a new thromboplastin reagent lot, only 9% of patients with target range aPTTs had anti-factor Xa heparin levels below 0.35 U/mL while 91% of patients had therapeutic anti-factor Xa heparin levels (positive predictive value = 91%). The Pearson correlation coefficient ( r ) for the new thromboplastin reagent lot was 0.93. The target aPTT range established with the new thromboplastin reagent lot was 61 to 100 seconds. CONCLUSION: Monitoring aPTTs without standardizing the thromboplastin reagent may not adequately reflect therapeutic heparin levels. Despite apparently target aPTTs, patients treated with UFH may be under-anticoagulated. Our new anti-Xa-adjusted target aPTT range shows an increase in the positive predictive value of aPTTs. Large-scale clinical studies are needed to determine the optimal anti-factor Xa range for ACS patients treated with UFH, with further refinements if glycoprotein IIb/IIIa inhibitors are concomitantly used and to show a benefit in clinical outcomes for monitoring plasma heparin levels with anti-factor Xa heparin levels. Institutional standardization of the aPTT is necessary to ensure optimal patient care when changing thromboplastin reagents.

Acute Disease↗

PubMed2004

Treatment of coronary aneurysm in acute myocardial infarction with AngioJet thrombectomy and JoStent coronary stent graft.

A 54-year-old male with a history of coronary artery disease with a percutaneous transluminal coronary angioplasty and stenting presented to the emergency with an acute myocardial infarction. The patient underwent angiography which showed in-stent thrombosis of the right coronary artery along with 2 aneurysms proximal to the lesion. The right coronary artery was treated with AngioJet rheolytic thrombectomy and the JoStent coronary stent graft. To our knowledge, this is the first report of the use of the AngioJet rheolytic thrombectomy and the JoStent coronary stent graft in acute myocardial infarction.

Acute Disease↗

PubMed2004

Hybrid revascularization using percutaneous coronary intervention and robotically assisted minimally invasive direct coronary artery bypass surgery.

Hybrid revascularization (HR) combines staged percutaneous coronary intervention (PCI) on stenoses in the non-left anterior descending (LAD) territories with minimally invasive direct coronary artery bypass (MIDCAB) using the left internal thoracic artery (LITA) to the LAD. The LITA-to-LAD graft, which has a 5-year patency rate of 95%, is the major determinant of the long-term survival for patients. Thus, HR aims to perform full revascularization without compromising the survival advantage of the LITA-to-LAD graft, while preserving the minimally invasive advantages associated with the percutaneous treatment of symptomatic coronary stenoses. We investigated whether HR was a valid alternative to conventional coronary artery bypass graft surgery in patients with multivessel coronary artery disease. We also present our early experiences with HR using a combined approach of advanced PCI and robotically-assisted MIDCAB.

Aged↗

PubMed2004

AngioJet thrombectomy.

The AngioJet rheolytic thrombectomy system is designed to remove thrombus with the Venturi-Bernoulli effect, with multiple high-velocity, high-pressure saline jets which are introduced through orifices in the distal tip of the catheter to create a localized low-pressure zone, resulting in a vacuum effect with the entrainment and dissociation of bulky thrombus. Rheolytic thrombectomy with the AngioJet catheter can reduce the thrombus burden in the setting of AMI and degenerated SVGs. The long-term follow-up appears to be favorable in patients treated with rheolytic thrombectomy in the setting of acute myocardial infarction over conventional primary angioplasty.

Angina, Unstable↗

PubMed2002

Retinal embolization during carotid angioplasty and stenting: mechanisms and role of cerebral protection systems.

Carotid stenting has become an accepted alternative to endarterectomy, but fear of embolic stroke has impeded its generalized application. The retina provides a unique observatory for the study of emboli, which may occur either directly or indirectly via collaterals to the ophthalmic artery. Systems under development for cerebral protection differ in their capacity to trap small emboli and in their protection of the collateral circulation. We evaluated 118 sequential patients undergoing carotid stenting using fundoscopy, fluorescein retinal angiography, and visual field examination. The site and size of emboli was assessed, and degree of edema estimated. All patients were treated using distal protection during carotid stent implantation: 38 patients with the Théron system (using routine flushing toward the external carotid) and 80 patients with the Percusurge system (aspiration only). Retinal embolization occurred in 6 of the 118 patients (4%), of whom 2 were symptomatic (1.7%). Using the Théron system, 5 of 38 patients (13.2%) had emboli while 1 of 80 (1.25%) had emboli using the Percusurge system (P = 0.019). Symptoms occurred only with emboli >20 microm. Symptomatic retinal embolization is uncommon during carotid stenting, but is more likely when external to internal carotid collaterals are not protected. Cerebral protection system designs should take into consideration the existence of collaterals and the need to protect against smaller sized emboli, which may cause blindness in the retinal circulation.

Angioplasty, Balloon↗

PubMed2002

Cutting balloon angioplasty.

The Cutting Balloon is a unique angioplasty device used in percutaneous coronary interventions. The advantage of the Cutting Balloon is its ability to reduce vessel stretch and vessel injury by scoring the vessel longitudinally rather than causing an uncontrolled disruption of the atherosclerotic plaque. The atherotomes deliver a controlled fault line during dilatation to ensure that the crack propagation ensues in an orderly fashion. Lower balloon inflation pressures (4 8 atmospheres) are recommended with the Cutting Balloon. The Cutting Balloon also dilates the target vessel with less force to decrease the risk of a neoproliferative response and in-stent restenosis.

Angioplasty, Balloon, Coronary↗