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Biomedical subjects

L S Dean

Publications and source records attributed to L S Dean.

At least 19 recordsLinked to original sources
PubMed2001

Effect of abciximab on cardiac enzyme elevation after transluminal extraction atherectomy (TEC) in high-risk saphenous vein graft lesions: comparison with a historical control group.

Saphenous vein graft (SVG) intervention has been associated with an increased incidence of distal embolization. Long lesions and lesions associated with thrombus are particularly at increased risk. This study was performed to determine whether abciximab may decrease this risk in high risk SVG angioplasty. From June 1994 to June 1998, 84 patients with at least one high risk factor, i.e., lesion length >20 mm or angiographic evidence of thrombus, underwent Transluminal extraction atherectomy (TEC) procedure followed by balloon dilatation or stenting. Of these 84 patients, 37 who had procedure after September 1995 underwent TEC with abciximab (Abciximab Group) and 47 who had their procedure before that date had TEC without abciximab thereby serving as historic control (Non-Abciximab Group). All patients had normal pre-procedure CK and CK-MB. Total creatine kinase (CK) and CK-MB were measured every 8 hr post-procedure for 24 hr. Baseline demographics, angiographic characteristics, incidence of LV dysfunction and triple vessel disease were similar between the two groups. Graft age was similar between two groups (122 +/- 70 vs. 117 +/- 54 months). Graft diameter, pre and post-procedure percent stenoses were not different between the two groups. Stents were used in 65% in the Abciximab group and 45% in Non-Abciximab group (P = 0. 14). There was no in-hospital repeat PTCA, urgent bypass surgery, or cardiac death. There was no difference between the two groups in regards to the incidence of any elevation of total CK (27% vs. 21. 3%) or CK-MB (54% vs. 51%). When used in conjunction with TEC in treating high risk vein graft lesions, abciximab did not reduce post procedure CK-MB elevation in this patient population.

Abciximab↗
PubMed2001

Neostigmine combined with bupivacaine, clonidine, and sufentanil for spinal labor analgesia.

UNLABELLED: We previously found that spinal clonidine prolongs labor analgesia when combined with spinal bupivacaine and sufentanil. We sought to determine whether the addition of spinal neostigmine to these drugs would further enhance labor analgesia. By use of a combined spinal/epidural technique, 36 patients were randomized to receive a hyperbaric spinal injection of bupivacaine 2.5 mg plus clonidine 50 microg and sufentanil 10 microg with or without neostigmine 10 microg. Pain, maternal hemodynamics, fetal heart rate, nausea, pruritus, sedation, motor block, sensory levels to pinprick, and maternal oxygen saturation were assessed at regularly specified intervals after spinal injection until additional analgesia was requested. The duration of spinal analgesia was similar between groups (215 +/- 60 min in the Control group versus 205 +/- 62 min in the Neostigmine group). Likewise, pain scores, the duration of labor, Apgar scores, and side effects were similar between groups except that patients administered neostigmine experienced significantly more nausea and vomiting (53% vs 7%, P = 0.01). We conclude that spinal neostigmine 10 microg produces severe nausea and does not potentiate the duration of spinal analgesia in laboring women from spinal bupivacaine, clonidine, and sufentanil. IMPLICATIONS: Spinal neostigmine 10 microg as an adjunct to spinal bupivacaine, clonidine, and sufentanil produces severe nausea and fails to potentiate analgesia in laboring women.

Adjuvants, Anesthesia↗
PubMed2000

Randomized comparison of GR-II stent and Palmaz-Schatz stent for elective treatment of coronary stenoses.

BACKGROUND: This prospective multicenter randomized clinical trial was designed to evaluate the long-term angiographic and clinical outcomes of elective treatment with the GR-II stent compared with the Palmaz-Schatz (PS) stent in patients with coronary stenoses. METHODS AND RESULTS: Seven hundred fifty-five patients with myocardial ischemia and de novo native coronary stenoses in 3- to 4-mm vessels were randomly assigned to the PS (375 patients) or the GR-II stent (380 patients). The primary end point was 12-month target lesion revascularization (TLR)-free survival. Angiography was performed at baseline and at follow-up in the first 300 consecutive patients to assess the frequency of angiographic restenosis. Procedure success was 98.5% for the GR-II stent and 99.4% for the PS stent (P:=0.19). At 30 days, patients assigned to the GR-II stent had a higher stent thrombosis rate (3.9% versus 0.3% for PS stent, P:<0.001) and TLR rate (3.9% versus 0.5% for PS stent, P:<0.001). The GR-II group had a higher follow-up restenosis frequency (47.3% versus 20.6% for the PS group, P:<0.001) and a lower 12-month TLR-free survival rate (71.7% versus 83.9% for the PS group, P:<0. 001). Multivariate logistic regression analysis identified a smaller final stent minimal lumen diameter (odds ratio [OR] 2.49, 95% CI 1. 56 to 3.98; P:<0.001), diabetes mellitus (OR 2.14, 95% CI 1.42 to 3. 22; P:<0.001), and use of the GR-II stent (OR 1.78, 95% CI 1.20 to 2. 64; P:<0.01) as independent determinants of 12-month TLR. CONCLUSIONS: On the basis of these long-term follow-up data, we conclude that use of the GR-II stent should be limited to the acute treatment of abrupt or threatened closure after failed conventional balloon angioplasty procedures.

Analysis of Variance↗
PubMed2000

Long-term (three years) effect of estrogen replacement therapy on major adverse cardiac events in postmenopausal women after intracoronary stenting.

This study examined whether estrogen replacement therapy (ERT) in postmenopausal women impacts intermediate and long-term outcome after successful coronary stenting. Our findings offer evidence that ERT significantly reduces target lesion revascularization after intracoronary stenting in postmenopausal patients who are on ERT before the intervention.

Angioplasty, Balloon, Coronary↗
PubMed2000

Percutaneous treatment of catheter-induced dissection of the left main coronary artery and adjacent aortic wall: a case report.

Left main coronary artery dissection complicating selective coronary angiography is uncommon. Moreover, aortic root dissection associated with coronary intervention is underreported and may require urgent surgical intervention. During percutaneous coronary angioplasty of a catheter-induced left main coronary artery dissection, retrograde dissection of the adjacent aortic root occurred. Both were successfully treated by stenting of the left main coronary artery. Cathet. Cardiovasc. Intervent. 49:86-89, 2000.

Aged↗
PubMed2000

Ropivacaine.

Ropivacaine (Naropin, AstraZeneca) is a long-acting amide local anaesthetic released for clinical use in 1996. Similar to bupivacaine, ropivacaine is equally effective for s.c. infiltration, epidural and peripheral nerve block for surgery, obstetric and post-operative analgesia. Ropivacaine differs from most other amide-type local anaesthetics in that it is marketed as a pure S-enantiomer, instead of as a racemate. This feature improves the safety of ropivacaine, and, indeed, studies have shown ropivacaine to have less cardiovascular and CNS toxicity than bupivacaine. Ropivacaine is nearly identical to bupivacaine in onset, quality and duration of sensory block, but it produces less motor block. Whether or not the motor sparing effect of ropivacaine is due to a lower relative potency compared to bupivacaine is a matter of intense debate. Despite a better safety profile, the increased cost of ropivacaine may limit its clinical utility.

Amides↗
PubMed1999

Early results of percutaneous intervention for severe coexisting carotid and coronary artery disease.

Fifty-one patients with severe coexisting carotid and symptomatic coronary artery occlusive disease successfully underwent staged or simultaneous coronary angioplasty and carotid stenting. One pericardial effusion and 2 minor strokes with full recovery occurred in the hospital, but no major neurologic events, myocardial infarction, or death were observed and no repeat revascularization was required within the 30-day follow-up.

Aged↗
PubMed1999

Immediate and late outcomes of subclavian artery stenting.

Stenting for subclavian artery occlusive disease is being increasingly utilized. To determine the immediate and late outcome of subclavian artery stenting, we studied 38 consecutive patients in whom the procedure was attempted. Technical and clinical success was achieved in 35 patients without complications. Failures occurred only in completely occluded arteries. Late clinical success was demonstrated in 31 patients. Three patients had recurrent symptoms. Two had angiographic restenosis within 4 months of the procedure; both were successfully redilated. The third patient had a new lesion, which was successfully stented. One patient died from lung cancer 10 months after the procedure. We conclude that stenting for subclavian artery occlusive disease has favorable immediate and late clinical outcomes and may be considered as a primary therapy.

Aged↗
PubMed1999

Does platelet glycoprotein IIb/IIIa receptor antibody improve in-hospital outcome of coronary stenting in high-risk thrombus containing lesions?

Coronary stenting in acute coronary syndromes probably increases the risk of acute stent thrombosis. Recently, use of platelet glycoprotein IIb/IIIa receptor antibody has been shown to improve percutaneous transluminal coronary angioplasty (PTCA) outcomes in high risk lesions. The purpose of this analysis was to determine safety and efficacy of platelet glycoprotein IIb/IIIa receptor antibody administration in patients receiving coronary stents in high-risk lesions. Between October 1995 and November 1996, 282 patients with acute ischemic syndromes received coronary stents at our center: 73 had thrombus containing lesions--40 presented with AMI and 33 with unstable angina and make up the study population. The mean age of these patients was 61+/-13 years, 56 were male, 35 had a history of myocardial infarctions (MI), 21 had prior coronary artery bypass graft (CABG), and 21 had prior PTCA. Coronary stenting was used for suboptimal result in 46 patients (63%), threatened closure in 25 patients (34%), and acute closure in 2 patients (3%). Platelet glycoprotein IIb/IIIa receptor antibody was administered during the procedure in 74% and after the procedure in 26%. A total of 115 stents were deployed (Gianturco-Roubin 80, Palmaz-Schatz 29, and Wallstent 6) in 24 LAD, 21 RCA, 15 LCX, and 13 saphenous vein graft (SVG) lesions. Procedural success was 100%. The mean diameter stenosis before and after intervention was 60%+/-31% and 4%+/-14%, respectively. In-hospital events included 1 Q-wave MI (1.4%), 13 non-Q-wave MI (18%), and 1 death (1.4%). There was no subacute stent thrombosis, emergency CABG, or repeat PTCA. Significant in-hospital bleeding complications were noted in seven (10%) patients, with five patients (6.8%) requiring blood transfusions. In this series of patients with acute ischemic syndromes associated with angiographic evidence of thrombus, combined use of platelet glycoprotein IIb/IIIa receptor antibody and stenting resulted in a very low incidence of subacute stent thrombosis and emergency target lesion revascularization. However, bleeding complications were higher than expected with conventional antiplatelet therapy following routine stenting.

Aged↗
PubMed1999

Long-term follow-up study of coronary reconstruction with multiple stents.

BACKGROUND: Conventional balloon angioplasty of very long de novo coronary lesions or very long coronary dissection caused by angioplasty is associated with low success and high complication rates. Multiple intracoronary stents have been used to treat both conditions, although long-term efficacy has not been defined. METHODS AND RESULTS: Between June 1993 and December 1995, 47 consecutive patients underwent native coronary angioplasty and stenting with 4 or more stents covering at least 2 consecutive diseased coronary segments. Preangioplasty and poststenting diameter stenoses were 81% +/- 13% and 21% +/- 12%, respectively. Reference vessel diameters were 3.53 +/- 0.55 mm proximal to the stents and 2. 95 +/- 0.62 mm distal to the stents. Average lesion length was 63 +/- 20 mm. The number of stents used was 4.5 +/- 1 per vessel (from 4 to 7). Gianturco Roubin I stents were used in all patients. Coronary Palmaz-Schatz stents were used as supplementary stents in 3 patients. Angiographic success was 100%. In-hospital outcomes include 1 death, 1 coronary bypass surgery, no Q-wave myocardial infarction, and 7 non-Q-wave myocardial infarctions. Long-term follow-up at 430 +/- 199 days was completed in all patients. Thirty-five (76%) patients were asymptomatic, 8 (17%) had class 1 or 2 angina, 1 had a myocardial infarction, 13 (28%) underwent repeat angioplasty, 2 patients had subsequent elective bypass surgery, and 3 died during follow-up. CONCLUSIONS: Multiple intracoronary stents for very long lesions or dissection can be performed with acceptable immediate and long-term outcomes.

Angioplasty, Balloon, Coronary↗
PubMed1999

Outcome after myocardial revascularization and renal transplantation: a 25-year single-institution experience.

BACKGROUND AND OBJECTIVE: Cardiac disease is a common cause of death in renal transplant recipients. This study retrospectively analyzes the results of myocardial revascularization procedures in these patients and makes recommendations for managing coronary atherosclerosis in patients with renal disease who already have a transplanted kidney or who may receive a kidney transplant. METHODS: Patients who had myocardial revascularization (coronary artery bypass grafting [CABG] or percutaneous transluminal coronary angioplasty [PTCA]) and renal transplantation at the authors' institution between 1968 and 1994 were analyzed. Patient, procedural, and institutional variables were used for actuarial analyses of survival, as well as multivariate analyses of risk factors for death. RESULTS: Eighty-three of 2989 renal transplant patients required myocardial revascularization either before or after their transplant, and diabetes mellitus was the cause of renal failure in 42% of these patients. Standard coronary angiography, CABG, and PTCA techniques were used without periprocedural renal allograft loss. Actuarial patient survival was 89%, 77%, and 65% at 1, 3, and 5 years after the last procedure (transplantation or revascularization). Cardiac disease was the most common mode of death. Early-phase risk factors for death by multivariate analysis included hypertension and revascularization before 1989. Late-phase risk factors for death included diabetes mellitus, higher number of pre-CABG myocardial infarctions, renal transplantation before 1984, older age, and unstable angina before CABG. CONCLUSIONS: Myocardial revascularization can be performed with acceptable short- and long-term results in patients with renal disease who have renal transplantation either before or after the revascularization procedure. Diabetes mellitus was a highly prevalent condition among these patients, and cardiac disease was their most common mode of death. PTCA and CABG, as performed at this institution, posed little risk for renal allograft loss. Modification of risk factors for coronary atherosclerosis, rigorous cardiac evaluation of patients at risk for coronary artery disease before renal transplantation, and aggressive use of revascularization procedures to decrease the incidence of myocardial infarction are proposed as ways to prolong the survival of renal transplant patients with ischemic heart disease.

Coronary Artery Disease↗
PubMed1999

Neurological monitoring during carotid artery stenting: the Duck Squeezing Test.

PURPOSE: To examine the usefulness of a novel method for neurological monitoring during carotid artery stenting (CAS). METHODS: The records of patients who underwent elective CAS between June 1996 and October 1998 were reviewed to identify those who had neurological changes during the procedure. We examined whether the neurological change had been detected by a change in the ability of the patient to respond to predetermined commands involving a small rubber duck placed in the contralateral hand. RESULTS: hundred seventy patients (320 vessels) underwent monitoring using the Duck Squeezing Test; 10 suffered neurological events during the procedure. Four of these were transient and temporally related to balloon inflation. Another 6 were tentatively ascribed to distal embolism. All instances were accompanied by a change in the patient's ability to perform the Duck Squeezing Test, which allowed the identification of the abnormal clinical situation. In addition, there were 4 false-positive tests secondary to the patient accidentally dropping the rubber duck. CONCLUSIONS: The Duck Squeezing Test is a sensitive and specific method for monitoring patients during elective CAS. Its practical applicability is based on sound neurophysiological concepts, which underscore the clinical importance of the test.

Adult↗
PubMed1998

Elective carotid artery stenting in the presence of contralateral occlusion.

Significant carotid stenosis in the presence of an occluded contralateral artery has a poor prognosis with medical therapy alone. Carotid cross clamping during surgical endarterectomy results in critical flow reductions in patients with inadequate collateral flow, and represents a significant risk for procedural strokes. Carotid stenting is being evaluated as an alternative to endarterectomy. We describe the immediate and late outcome of a series of 26 patients treated with carotid stenting in the presence of contralateral carotid occlusion. The mean age of the patients in this group was 65 +/- 9 years, 23 (89%) were men and 10 (39%) were symptomatic from the vessel treated. The procedural success of carotid stenting in this group of patients was 96%. The mean diameter stenosis was reduced from 76 +/- 15% to 2.8 +/- 5%. There was 1 (3.8%) minor stroke in a patient who developed air embolism during baseline angiography. At late follow-up there was no neurologic event in any patient at a mean of 16 +/- 9.5 months after the procedure. Thus, carotid stenting of lesions with contralateral occlusion can be performed successfully with a low incidence of procedural neurologic complications and late stroke.

Aged↗
PubMed1998

Predictors of stroke complicating carotid artery stenting.

BACKGROUND: The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection. METHODS AND RESULTS: We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes. CONCLUSIONS: During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Aged↗
PubMed1998

Angioplasty of totally occluded old vein grafts with new interventional techniques: a long-term follow-up study.

The long-term patency of saphenous vein graft (SVG) lesions after intervention has been shown to be improved with new interventional techniques such as stents. Long-term outcome of patients undergoing successful angioplasty of totally occluded old SVGs with new devices is unknown. From July 1994 to June 1996, 19 patients with totally occluded old SVGs had successful angioplasty with new interventional techniques. Mean SVG age was 123 +/- 8 mo. Thrombolysis in myocardial infarction trial (TIMI) flow was 0 in all target lesions. TIMI 2 or 3 flow was restored after angioplasty in all patients. Intracoronary urokinase, transluminal extractional atherectomy, and stenting were used in 14, 12, and 6 patients, respectively. There was one in-hospital death due to ongoing myocardial infarction, no recurrent infarction, and no repeat angioplasty or bypass surgery in the hospital. At follow-up of 21 +/- 1 mo, there was one sudden death and one myocardial infarction. Five patients had repeat coronary bypass surgery, and 4 had repeat angioplasty. Thirteen patients remained asymptomatic, and 4 had angina. The long-term outcome of patients who had successful reopening of occluded old SVGs is encouraging in this small sample.

Aged↗
PubMed1998

Relationship between oversizing of self-expanding stents and late loss index in carotid stenting.

Stenting of the internal carotid artery is facilitated by stenting across the carotid bifurcation and sizing the diameter of a self-expanding stent to the large common carotid segment. This usually results in marked oversizing of the self-expanding stent in the internal carotid segment. This study was done to determine the relationship between stent oversizing and late luminal loss index after stenting of the internal carotid artery. Between September 1995 and March 1997, there were 165 patients (189 vessels) who underwent successful carotid stenting with self-expanding stents. Fifty-nine patients (63 vessels) had six-month follow-up carotid angiograms and on-line quantitative angiographic analysis. The mean reference diameter of the internal carotid arteries was 4.93+/-1.31 mm. Nominal stent size was 5 mm in 4 patients, 6 mm in 6 patients, 8 mm in 106 patients, 10 mm in 77 patients, and 12 mm in 1 patient. The average stent/patient was 1.03+/-0.16. There were three patients who had more than 50% diameter renarrowing at follow-up. The mean late loss index was 0.25+/-0.41. By linear regression analysis, there was no clear linear relationship between stent oversizing and late loss index after stenting (correlation coefficient = -0.21, P = 0.09). When analysis of variance with linear contrast was used to analyze six groups of different stent/artery ratios (from 1.4 to > or = 2), late loss indexes are significantly lower in the groups of high stent/artery ratio than the groups of low stent/artery ratio (P = 0.01). The process of oversizing of self-expanding stents deployed in the internal carotid artery does not appear to be associated with late restenosis and high stent/artery ratio seems to be associated with low late loss index.

Adult↗