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1.
Int J Stroke ; 5(1): 40-6, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20088993

ABSTRACT

RATIONALE: Carotid endarterectomy (CEA) and medical therapy were shown superior to medical therapy alone for symptomatic (> or =50%) and asymptomatic (> or =60%) stenosis. Carotid angioplasty stenting (CAS) offers a less invasive alternative. Establishing safety, efficacy, and durability of CAS requires rigorous comparison with CEA in symptomatic and asymptomatic patients. AIMS: The objective is to compare the efficacy of CAS versus CEA in patients with symptomatic (> or =50%) or asymptomatic (> or =60%) extracranial carotid stenosis. DESIGN: The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) is a prospective, randomized, parallel, two-arm, multi-center trial with blinded endpoint adjudication. Primary endpoints are analyzed using standard time-to-event statistical modeling with adjustment for major baseline covariates. Primary analysis is on an intent-to-treat basis. STUDY OUTCOMES: The primary outcome is the occurrence of any stroke, myocardial infarction, or death during a 30-day peri-procedural period, and ipsilateral stroke during follow-up of up to four years. Secondary outcomes include restenosis and health-related quality of life.


Subject(s)
Carotid Arteries/surgery , Carotid Stenosis/surgery , Endarterectomy, Carotid , Stents , Computer Security , Data Interpretation, Statistical , Endarterectomy, Carotid/adverse effects , Endarterectomy, Carotid/instrumentation , Humans , Patient Selection , Research Design , Sample Size , Stents/adverse effects , Treatment Outcome
2.
J Cardiovasc Surg (Torino) ; 47(2): 153-60, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16572089

ABSTRACT

Carotid endarterectomy is the preferred method for cerebral revascularization in patients with symptomatic and asymptomatic high-grade extracranial carotid artery stenosis. Carotid artery stenting has recently emerged as a less invasive alternative to endarterectomy. Carotid stenting has been demonstrated to be technically feasible and safe in high-risk patients with current data indicating clinical equipoise with respect to endarterectomy. It is clear that carotid stenting will continue to be performed at increasing rates after these encouraging outcomes. Therefore, it is anticipated that there will be a corresponding increase in the number of in-stent restenosis cases. Considerable controversy exists regarding the clinical significance, natural history, threshold for management, and appropriate intervention of recurrent carotid stenosis after endarterectomy and after stenting. This review analyses current information on this important clinical problem and presents evidence-based recommendations for the diagnosis and management of recurrent carotid stenosis.


Subject(s)
Angioplasty , Carotid Stenosis/surgery , Endarterectomy, Carotid , Graft Occlusion, Vascular/surgery , Stents , Angioplasty/adverse effects , Endarterectomy, Carotid/adverse effects , Graft Occlusion, Vascular/diagnosis , Graft Occlusion, Vascular/epidemiology , Humans , Incidence , Stents/adverse effects
3.
J Vasc Surg ; 34(5): 930-8, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11700497

ABSTRACT

PURPOSE: Increased transforming growth factor-beta(1) (TGF-beta(1)) activity is associated with chronic venous insufficiency (CVI) disease progression and dermal skin pathology. Because TGF-beta(1) stimulates collagen synthesis and alters the levels of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), we investigated the hypothesis that increased TGF-beta(1) activity is associated with differences in messenger RNA and protein levels of MMPs and TIMP-1 in patients with CVI. METHODS: One hundred ten biopsies of the lower calf and lower thigh in 73 patients were snap frozen in liquid nitrogen and stratified into six groups according to the clinical etiologic anatomic distribution pathophysiology disease classification. One set of lower-calf and lower-thigh biopsies were analyzed for MMP-1 and TIMP-1 gene expression with quantitative reverse transcription and competitive polymerase chain reaction. A second set of biopsies was analyzed for the active and latent forms of MMP-1, MMP-2, and MMP-9 as well as for TIMP-1 by western blotting, gelatin zymography, and tissue localization by immunohistochemistry (IHC). RESULTS: Compared with the control, MMP-1 messenger RNA was increased in class-4 and class-6 patients (P < or =.01), whereas TIMP-1 was increased in class-6 patients only (P < or =.05). However, there were no differences in total protein between MMP-1 and TIMP-1. Active MMP-2 protein increased in class-4 and class-5 patients compared with active MMP-1 and TIMP-1 (P < or =.01). Western blotting did not identify the active component of MMP-9. Similarly, only the latent form of MMP-9 was observed by gelatin zymography, whereas both the latent and active forms of MMP-2 were observed. IHC demonstrated MMP-1 and MMP-2 in dermal fibroblasts and in perivascular leukocytes. TIMP-1 was observed in basal-layer keratinocytes of the epidermis only. MMP-9 was not detected by IHC. CONCLUSION: MMP synthesis is regulated at both the transcriptional and post-transcriptional levels in CVI. Our data suggest that post-translational modifications are key to functional regulation. Dermal fibroblasts and migrating leukocytes are probable cellular sources of MMPs. Increased active MMP-2 levels in class-4 and class-5 patients indicate tissue remodeling caused by pre-ulcer and postulcer environmental stimuli. These data suggest that alterations in MMP-2 activity, in conjunction with TGF-beta(1)-mediated events, cause an imbalance in tissue remodeling leading to a pro-ulcer-forming environment.


Subject(s)
Matrix Metalloproteinase 1/physiology , Matrix Metalloproteinase 2/physiology , Matrix Metalloproteinase 9/physiology , Tissue Inhibitor of Metalloproteinase-1/physiology , Transforming Growth Factor beta/metabolism , Venous Insufficiency/metabolism , Blotting, Western , Female , Gene Expression , Humans , Immunohistochemistry , Male , Matrix Metalloproteinase 1/genetics , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 9/genetics , Middle Aged , RNA, Messenger , Reverse Transcriptase Polymerase Chain Reaction , Tissue Inhibitor of Metalloproteinase-1/genetics , Venous Insufficiency/enzymology
4.
Microvasc Res ; 62(3): 252-62, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11678628

ABSTRACT

VEGF is a key regulator of vascular permeability. However, its signaling pathways are incompletely understood. We tested the hypothesis that VEGF regulates endothelial cell (EC) permeability by activating PKB/akt, NOS, and MAP kinase dependent pathways using human umbilical vein EC (HUVEC). Permeability was measured from FITC-dextran 70-kDa flux across the EC monolayer at baseline and after VEGF at 0.034, 0.068, 1, 10, and 100 nM. VEGF increased HUVEC permeability to FITC-dextran in a dose-dependent manner. VEGF (1 nM) increased permeability from 3.9 x 10(-6) +/- 0.7 x 10(-6) to 14.0 x 10(-6) +/- 1.7 x 10(-6) cm/s (mean +/- SEM; P < 0.001). Permeability changes were also assessed after treatment with 1, 10, and 100 nM wortmannin (PI 3-kinase inhibitor); 0.01, 0.1, and 1.0 nM LY294002 (PI 3-kinase inhibitor); 200 microM l-NMMA (NOS inhibitor); 2.7 microM AG126 (p42/44(MAPK) inhibitor); and 0.006, 0.06, and 0.6 microM SB203580 (p38(MAPK) inhibitor). All inhibitors blocked VEGF-induced permeability changes. Our data demonstrate that (1) VEGF increases permeability of EC monolayers in a dose-dependent fashion, and (2) VEGF-induced permeability is mediated through PI-3 kinase-PKB, NOS, and MAP-kinase signaling cascades. These observations suggest that microvascular hyperpermeability associated with inflammation and vascular disease is mediated by activation of these EC signaling pathways.


Subject(s)
Capillary Permeability/drug effects , Endothelial Growth Factors/pharmacology , Endothelium, Vascular/drug effects , Endothelium, Vascular/enzymology , Lymphokines/pharmacology , MAP Kinase Signaling System/physiology , Nitric Oxide Synthase/metabolism , Protein Serine-Threonine Kinases , Proto-Oncogene Proteins/metabolism , Cells, Cultured , Dose-Response Relationship, Drug , Endothelium, Vascular/cytology , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Humans , Infant, Newborn , Kinetics , Nitric Oxide Synthase/drug effects , Nitric Oxide Synthase Type III , Protein-Tyrosine Kinases/drug effects , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins/drug effects , Proto-Oncogene Proteins c-akt , Umbilical Veins/cytology , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
6.
J Vasc Surg ; 33(2): 220-5; discussion 225-6, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11174771

ABSTRACT

PURPOSE: Carotid angioplasty-stenting (CAS) has been advocated as an alternative to carotid endarterectomy (CEA) in patients with restenotic lesions after prior CEA, primary stenoses with significant medical comorbidities, and radiation-induced stenoses. The incidence of restenosis after CAS and its management remains ill defined. We evaluated the incidence and management of in-stent restenosis after CAS. METHODS: Patients with asymptomatic (61%) and symptomatic (39%) carotid stenosis of > or = 80% underwent CAS between September 1996 and May 2000; there were 50 procedures and 46 patients (26 men and 20 women). All patients were followed up clinically and underwent duplex ultrasonography (DU) at 3- to 6-month intervals. In-stent restenoses > or = 80% detected with DU were further evaluated by means of angiography for confirmation of the severity of stenosis. RESULTS: No periprocedural or late strokes occurred in the 50 CAS procedures during the 30-day follow-up period. One death (2.2%) that resulted from myocardial infarction was observed 10 days after discharge following CAS. During a mean follow-up period of 18 +/- 10 months (range, 1-44 months), in-stent restenosis was observed after four (8%) of the 50 CAS procedures. Angiography confirmed these high-grade (> or = 80%) in-stent restenoses, which were successfully treated with balloon angioplasty (3) or angioplasty and restenting (1). No periprocedural complications occurred, and these patients remained asymptomatic and without recurrent restenosis over a mean follow-up time of 10 +/- 6 months. CONCLUSIONS: We recommend CAS for post-CEA restenosis, primary stenoses in patients with high-risk medical comorbidities, and radiation-induced stenoses. In-stent restenoses occurred after 8% of CAS procedures and were managed without complications with repeat angioplasty or repeat angioplasty and restenting.


Subject(s)
Angioplasty, Balloon , Carotid Arteries , Carotid Stenosis/therapy , Stents , Aged , Angioplasty, Balloon/adverse effects , Carotid Arteries/diagnostic imaging , Carotid Stenosis/diagnostic imaging , Endarterectomy, Carotid , Female , Follow-Up Studies , Humans , Male , Radiography , Recurrence , Stents/adverse effects , Ultrasonography, Doppler, Duplex
7.
J Vasc Surg ; 33(2 Suppl): S111-6, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11174821

ABSTRACT

OBJECTIVE: Carotid bifurcation angioplasty and stenting (CBAS) has generated controversy and widely divergent opinions about its current therapeutic role. To resolve differences and establish a unified view of CBAS' present role, a consensus conference of 17 experts, world opinion leaders from five countries, was held on November 21, 1999. METHODS: These 17 participants had previously answered 18 key questions on current CBAS issues. At the conference these 18 questions and participants' answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus, (prevailing opinion), or divided opinion (disagreement). RESULTS: Conference discussion added two modified questions, placing a total of 20 key questions before the participants, representing four specialties (interventional radiology, seven; vascular surgery, six; interventional cardiology, three; neurosurgery, one). It is interesting that consensus was reached on the answers to 11 (55%) of 20 of the questions, and near consensus was reached on answers to 6 (30%) of 20 of the questions. Only with the answers to three (15%) of the questions was there persisting controversy. Moreover, both these differences and areas of agreement crossed specialty lines. Consensus Conclusions: CBAS should not currently undergo widespread practice, which should await results of randomized trials. CBAS is currently appropriate treatment for patients at high risk in experienced centers. CBAS is not generally appropriate for patients at low risk. Neurorescue skills should be available if CBAS is performed. When cerebral protection devices are available, they should be used for CBAS. Adequate stents and technology for performing CBAS currently exist. There were divergent opinions regarding the proportions of patients presently acceptable for CBAS treatment (<5% to 100%, mean 44%) and best treated by CBAS (<3% to 100%, mean 34%). These and other consensus conclusions will help physicians in all specialties deal with CBAS in a rational way rather than by being guided by unsubstantiated claims.


Subject(s)
Angioplasty/methods , Carotid Artery Diseases/surgery , Patient Selection , Practice Guidelines as Topic/standards , Stents , Angioplasty/instrumentation , Attitude of Health Personnel , Benchmarking , Clinical Competence/standards , Diffusion of Innovation , Evidence-Based Medicine , Humans , Needs Assessment , Research , Risk Factors , Treatment Outcome
8.
J Vasc Surg ; 33(2 Suppl): S117-23, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11174822

ABSTRACT

Carotid angioplasty-stenting (CAS) is a relatively new endovascular procedure that has been used increasingly in recent years. Its popularity is due to, at least in part, the perceived advantages of a less invasive treatment for extracranial carotid occlusive disease. However, valid data that contrast the efficacy of CAS and carotid endarterectomy (CEA), the gold standard for the treatment of symptomatic carotid stenosis, are not available. The Carotid Revascularization Endarterectomy versus Stent Trial (CREST) will contrast the relative efficacy of CAS with CEA in the prevention of stroke, myocardial infarction, or death during a 30-day periprocedural period or an ipsilateral stroke thereafter during a follow-up period extending up to 4 years. Stroke events will be verified by an adjudication committee masked to the assigned treatment. Secondary outcomes will (1) describe differential efficacy of CAS and CEA in men and women, (2) contrast periprocedural (30-day) morbidity and postprocedural (after 30-days) morbidity and mortality rates, (3) estimate and contrast the restenosis rates of the two procedures, (4) evaluate the differences in measures of health-related quality of life and cost effectiveness, and (5) identify subgroups of participants at differential risk for CAS and CEA. The primary eligibility criterion is a >50% stenosis of the carotid artery in patients with ipsilateral amaurosis fugax (transient monocular blindness), transient ischemic attack, or nondisabling stroke. Men and women will be eligible for the trial, but patients with medical conditions likely to limit their participation during the follow-up or to interfere with outcome evaluation will be excluded. After a credentialing and training phase, 2500 patients will be randomized to the treatments. Statistical analysis of the primary outcome will use standard survival methods.


Subject(s)
Angioplasty/standards , Carotid Artery Diseases/surgery , Endarterectomy, Carotid/standards , Stents , Angioplasty/adverse effects , Angioplasty/economics , Angioplasty/methods , Angioplasty/psychology , Carotid Artery Diseases/complications , Carotid Artery Diseases/mortality , Clinical Protocols , Cost-Benefit Analysis , Endarterectomy, Carotid/adverse effects , Endarterectomy, Carotid/economics , Endarterectomy, Carotid/methods , Endarterectomy, Carotid/psychology , Evidence-Based Medicine , Female , Follow-Up Studies , Humans , Male , Morbidity , Myocardial Infarction/etiology , Myocardial Infarction/prevention & control , Patient Selection , Quality of Life , Randomized Controlled Trials as Topic , Stroke/etiology , Stroke/prevention & control , Treatment Outcome
9.
Am J Med ; 109(7): 523-30, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11063952

ABSTRACT

PURPOSE: We performed a randomized, double-blind, placebo-controlled, multicenter trial to evaluate the relative efficacy and safety of cilostazol and pentoxifylline. PATIENTS AND METHODS: We enrolled patients with moderate-to-severe claudication from 54 outpatient vascular clinics, including sites at Air Force, Veterans Affairs, tertiary care, and university medical centers in the United States. Of 922 consenting patients, 698 met the inclusion criteria and were randomly assigned to blinded treatment with either cilostazol (100 mg orally twice a day), pentoxifylline (400 mg orally 3 times a day), or placebo. We measured maximal walking distance with constant-speed, variable-grade treadmill testing at baseline and at 4, 8, 12, 16, 20, and 24 weeks. RESULTS: Mean maximal walking distance of cilostazol-treated patients (n = 227) was significantly greater at every postbaseline visit compared with patients who received pentoxifylline (n = 232) or placebo (n = 239). After 24 weeks of treatment, mean maximal walking distance increased by a mean of 107 m (a mean percent increase of 54% from baseline) in the cilostazol group, significantly more than the 64-m improvement (a 30% mean percent increase) with pentoxifylline (P <0.001). The improvement with pentoxifylline was similar (P = 0.82) to that in the placebo group (65 m, a 34% mean percent increase). Deaths and serious adverse event rates were similar in each group. Side effects (including headache, palpitations, and diarrhea) were more common in the cilostazol-treated patients, but withdrawal rates were similar in the cilostazol (16%) and pentoxifylline (19%) groups. CONCLUSION: Cilostazol was significantly better than pentoxifylline or placebo for increasing walking distances in patients with intermittent claudication, but was associated with a greater frequency of minor side effects. Pentoxifylline and placebo had similar effects.


Subject(s)
Intermittent Claudication/drug therapy , Pentoxifylline/therapeutic use , Tetrazoles/therapeutic use , Vasodilator Agents/therapeutic use , Walking , Aged , Cilostazol , Double-Blind Method , Drug Administration Schedule , Exercise Test , Female , Humans , Male , Middle Aged , Pentoxifylline/administration & dosage , Pentoxifylline/adverse effects , Severity of Illness Index , Tetrazoles/administration & dosage , Tetrazoles/adverse effects , Time Factors , Treatment Outcome , Vasodilator Agents/administration & dosage , Vasodilator Agents/adverse effects
10.
J Endovasc Ther ; 7(5): 345-52, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11032252

ABSTRACT

PURPOSE: To present the results of a multicenter registry established to collect data on carotid stent procedures in patients with restenosis following carotid endarterectomy. METHODS: The procedural details, outcomes, and late follow-up results were collected from 14 centers in the United States. Thirty-day and late stroke and death rates were analyzed. RESULTS: Three hundred and thirty-eight patients (201 men; 71 +/- 8 years) underwent carotid stenting in 358 arteries. The average duration from carotid endarterectomy was 5.5 +/- 7.3 years. Sixty-one percent of the patients were asymptomatic. The overall 30-day stroke and death rate was 3.7%. The minor stroke rate was 1.7% (6/358), and the major nonfatal stroke rate was 0.8% (3/358). The fatal stroke rate was 0.3% (1/358), and the nonstroke-related death rate was 0.9% (3/338). There was 1 (0.3%) fatal and 1 (0.3%) nonfatal stroke during the follow-up period. The overall 3-year rate of freedom from all fatal and nonfatal strokes was 96% +/- 1% (+/- SE). CONCLUSIONS: Carotid artery stenting can be performed in patients with restenosis following carotid endarterectomy with 30-day complication rates comparable to those of most published studies on repeat carotid endarterectomy. Results of late follow-up suggest that this technique is durable and efficacious.


Subject(s)
Carotid Stenosis/therapy , Endarterectomy, Carotid , Stents , Aged , Female , Humans , Male , Postoperative Complications , Recurrence , Safety , Treatment Outcome
11.
Semin Vasc Surg ; 13(2): 139-43, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10879554

ABSTRACT

The Carotid Revascularization Endarterectomy versus Stent Trial (CREST) contrasts the relative efficacy of carotid endarterectomy (CEA) and carotid angioplasty-stent (CAS) in preventing primary outcomes of stroke, myocardial infarction, or death during a 30-day periprocedural period, or ipsilateral stroke over the follow-up period extending up to 4 years. Stroke events will be verified by an Adjudication Committee masked to the assigned treatment. The primary eligibility criterion is a significant (> or =50%) stenosis of the carotid artery in patients with transient ischemic attack or ipsilateral nondisabling stroke within the prior 180 days. Men and women will be eligible for the trial, but patients with medical conditions likely to limit their participation during the follow-up or to interfere with outcome evaluation will be excluded. After a credentialing and training phase, 2,500 patients will be randomized to the treatments. Statistical analysis of the primary outcome will employ standard survival techniques and will result in 90% power to detect annual differences between groups of 1.2% or higher in event rates of the primary outcomes.


Subject(s)
Carotid Stenosis/surgery , Endarterectomy, Carotid , Stents , Female , Humans , Male , Randomized Controlled Trials as Topic
13.
Semin Vasc Surg ; 13(1): 44-8, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10743889

ABSTRACT

Although the autogenous radiocephalic fistula is considered to be the ideal access for hemodialysis, significant changes in the demographics of patients undergoing angioaccess have occurred since its initial description in the 1960s. Patients presenting for initial access evaluation in contemporary practice are less likely to have arteries and veins suitable for autogenous fistula (AF) formation in the classic location. Physical examination of the upper extremity alone may be inadequate for selection of arteries and veins that will mature into a functioning AF. The authors have used duplex ultrasound (DU) to assess upper-extremity vasculature for planning of dialysis access procedures. Criteria for selection of arteries and veins and a detailed description of our DU examination protocol are reviewed. Routine use of upper-extremity DU has identified many patients with forearm veins that are suitable for use, but in locations remote from the optimal arterial inflow or too deep to facilitate easy needle cannulation. Modifications to the single-incision radiocephalic fistula that allow for expanded use of forearm veins identified by DU are described, and the technique of superficial venous transposition of forearm veins in particular is reviewed in detail. On the basis of our experience, we recommend the combination of upper-extremity planning DU and superficial venous transposition in the forearm to increase use of AF and reduce reliance on prosthetic bridging grafts (BG) in patients requiring access for hemodialysis.


Subject(s)
Arm/blood supply , Arm/diagnostic imaging , Arteriovenous Shunt, Surgical/methods , Ultrasonography, Doppler, Duplex , Arm/surgery , Humans , Renal Dialysis , Veins/surgery
15.
J Vasc Surg ; 31(1 Pt 1): 69-83, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10642710

ABSTRACT

PURPOSE: The modification of the distal anastomosis of polytetrafluoroethylene (PTFE) bypass grafts with vein interposition cuffs (VCs) has been reported to increase graft patency. However, the mechanisms that are responsible for this improved patency are unclear. Because intimal hyperplasia (IH) is a primary cause of prosthetic graft failure, we hypothesized that VCs affect the distal anastomosis by decreasing the IH response of the outflow artery. METHODS: Twenty-three female domestic Yorkshire pigs (mean weight, 35 kg) underwent 42 femoral PTFE bypass grafting procedures. The PTFE bypass grafts were separated into the following three groups according to distal anastomotic configuration: end-to-side anastomoses (ES), VCs, and cuffs constructed with PTFE (PCs). Four femoral arteries from two pigs served as healthy controls. At sacrifice, the grafts were perfusion fixed, and the distal anastomoses harvested at 1 and 4 weeks. The specimens were hemisected and serially sectioned to identify the heel, toe, and mid-anastomotic regions. The sections were cut into 5-microm segments and analyzed for intima and media thickness and area, intima/media area ratio, and the distribution of IH in the vein cuff. The roles of transforming growth factor-beta1 and platelet-derived growth factor-BB in IH development were assessed with immunohistochemistry. RESULTS: IH development was significantly lower at all areas of the anastomosis, with VCs compared with ES and PCs at 4 weeks (P

Subject(s)
Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis/adverse effects , Femoral Artery/pathology , Femoral Artery/surgery , Jugular Veins/transplantation , Polytetrafluoroethylene/adverse effects , Saphenous Vein/transplantation , Tunica Intima/pathology , Actins/analysis , Anastomosis, Surgical/methods , Animals , Becaplermin , Blood Vessel Prosthesis Implantation/methods , Disease Models, Animal , Female , Graft Survival , Hemodynamics , Hyperplasia/etiology , Hyperplasia/pathology , Hyperplasia/physiopathology , Immunohistochemistry , Materials Testing , Platelet-Derived Growth Factor/analysis , Prosthesis Design , Proto-Oncogene Proteins c-sis , Swine , Transforming Growth Factor beta/analysis , Vascular Patency
16.
J Am Osteopath Assoc ; 100(11 Suppl): S22-6, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11191118

ABSTRACT

Diagnosis and management of carotid arterial occlusive disease and its ensuing comorbid illnesses have been the focus of extensive debate during the past two decades. The development of sophisticated ultrasound technology has enabled us to objectively define the severity of carotid stenosis in regions commonly accountable for stroke. Results from several well-designed prospective randomized trials have enhanced our understanding of the epidemiology of this disease and have guided our judgment with regard to aggressive diagnosis and intervention. As clinicians, we have been charged to address underlying risk factors, including hyperlipidemia and smoking abuse, as well as concomitant coronary, renal, and lower extremity artery disease. Carotid endarterectomy coupled with optimal medical management is superior to medical management alone in asymptomatic patients with high-grade carotid stenosis (> 70% diameter reduction) and recently has been shown to have value for symptomatic patients with stenosis of 50% to 69%.


Subject(s)
Carotid Stenosis/diagnosis , Carotid Stenosis/therapy , Algorithms , Carotid Artery Diseases/diagnosis , Carotid Artery Diseases/therapy , Cerebral Angiography , Endarterectomy, Carotid , Humans , Risk Factors , Stents , Stroke/prevention & control , Ultrasonography, Doppler, Transcranial
17.
J Vasc Surg ; 31(4): 770-80, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10753285

ABSTRACT

PURPOSE: The purpose of this study was to test whether basic fibroblast growth factor (bFGF) participates in arterialized vein graft remodeling. METHODS: Rabbits underwent in vivo gene transfer and carotid interposition vein grafting. Segments of external jugular vein were infected with an adenovirus that expressed antisense bFGF RNA (Ad.ASbFGF) at 1 x 10(10) PFU/mL to inhibit new synthesis of bFGF by cells in the vein graft wall. Control rabbits were treated with either adenovirus that encoded beta-galactosidase (Ad.lacZ) at 1 x 10(10) PFU/mL or vehicle (phosphate-buffered saline solution [PBS]). At 3 days, 3 grafts per treatment group were harvested for the determination of gene expression of ASbFGF RNA by reverse transcriptase-polymerase chain reaction. Rabbits were killed, and perfusion was fixed 2 months after the grafting. Total wall thickness and lumen circumference of vein grafts and normal arteries were measured in cross sections. Calculated mean tangential stress (+/-SD) for the ASbFGF-treated group and controls was compared for significance. Grafts were immunohistochemically stained to assess bFGF protein production. RESULTS: Only the grafts infected with the Ad.ASbFGF gene expressed ASbFGF RNA. Grafts that were treated with Ad.ASbFGF displayed lower tangential stress (10.9 +/- 2.3 dynes/cm(2)) than PBS alone (22 +/- 2.8 dynes/cm(2)) or Ad. lacZ-treated controls (20.6 +/- 5.4 dynes/cm(2); P <.001). Tangential stress in the Ad.ASbFGF group was comparable to a normal carotid artery (13.9 +/- 2.1 dynes/cm(2)). The difference in mean total wall thickness was significant among the 3 treatment groups: Ad.ASbFGF, 164 +/- 3.4 microm); Ad.lacZ, 100 +/- 3.3 microm; and PBS, 96 +/- 3.6 microm; P <.01). Luminal circumference was not different among the groups. The Ad.ASbFGF-treated vein graft wall was composed of thick layers of concentric smooth muscle cells and elastin fibers in contrast to the sponge-like appearance observed in control arterialized vein grafts. Reduction in bFGF protein was noted only in the Ad.ASbFGF-treated group. CONCLUSION: Inhibition of bFGF synthesis in vivo with the use of adenoviral gene transfer of antisense RNA to bFGF promotes a vein graft with decreased tangential stress while maintaining the luminal area. The vein graft wall is remodeled and qualitatively resembles an artery so that wall tangential stress in Ad.ASbFGF and normal artery are not significantly different. The lack of significant difference in lumen circumference among groups suggests that wall thickening in the Ad. ASbFGF grafts is not at the expense of luminal narrowing. Our results suggest that ASbFGF RNA expression may represent an effective strategy in limiting the failure of arterialized venous conduits.


Subject(s)
Adenoviridae/genetics , Carotid Artery, Common/surgery , Fibroblast Growth Factor 2/physiology , Gene Expression Regulation, Viral , Gene Transfer Techniques , Jugular Veins/transplantation , RNA, Antisense/genetics , Analysis of Variance , Animals , Carotid Artery, Common/metabolism , Carotid Artery, Common/pathology , Carotid Artery, Common/physiopathology , Elastin/ultrastructure , Fibroblast Growth Factor 2/antagonists & inhibitors , Fibroblast Growth Factor 2/genetics , Hemorheology , Immunohistochemistry , Jugular Veins/metabolism , Jugular Veins/pathology , Jugular Veins/physiopathology , Male , Muscle, Smooth, Vascular/pathology , Muscle, Smooth, Vascular/physiopathology , Polymerase Chain Reaction , Rabbits , Stress, Mechanical , Up-Regulation
18.
J Vasc Surg ; 30(6): 1116-20, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10587398

ABSTRACT

PURPOSE: Carotid endarterectomy (CEA) has become one of the most commonly performed vascular procedures, because of the beneficial outcome it has when compared with medical therapy alone and because of the anatomic accessibility of the artery. In cases of distal carotid occlusive disease, high cervical carotid bifurcation, and some reoperative cases, access to the distal internal carotid artery may limit surgical exposure and increase the incidence of cranial nerve palsies. Mandibular subluxation (MS) is recommended to provide additional space in a critically small operative field. We report our experience to determine and illustrate a preferred method of MS. METHODS: Techniques for MS were selected based on the presence or absence of adequate dental stability and periodontal disease. All patients received general anesthesia with nasotracheal intubation before subluxation. Illustrations are provided to emphasize technical considerations in performing MS in 10 patients (nine men and one woman) who required MS as an adjunct to CEA (less than 1% of primary CEAs). Patients were symptomatic (n = 7) or asymptomatic (n = 3) and had high-grade stenoses demonstrated by means of preoperative arteriography. RESULTS: Subluxation was performed and stabilization was maintained by means of: Ivy loop/circumdental wiring of mandibular and maxillary bicuspids/cuspids (n = 7); Steinmann pins with wiring (n = 1); mandibular/maxillary arch bar wiring (n = 1); and superior circumdental to circummandibular wires (n = 1). MS was not associated with mandibular dislocation in any patient. No postoperative cranial nerve palsies were observed. Three patients experienced transient temporomandibular joint discomfort, which improved spontaneously within 2 weeks. CONCLUSION: Surgical exposure of the distal internal carotid artery is enhanced with MS and nasotracheal intubation. We recommend Ivy loop/circumdental wiring as the preferred method for MS. Alternative methods are used when poor dental health is observed.


Subject(s)
Carotid Artery, Internal/surgery , Carotid Stenosis/surgery , Endarterectomy, Carotid/methods , Mandible/surgery , Adult , Aged , Bone Nails , Bone Wires , Female , Humans , Male , Middle Aged , Postoperative Complications/etiology
19.
J Vasc Surg ; 30(6): 1129-45, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10587400

ABSTRACT

PURPOSE: Pathologic dermal degeneration in patients with chronic venous insufficiency (CVI) is characterized by aberrant tissue remodeling that results in stasis dermatitis, tissue fibrosis, and ulcer formation. The cytochemical processes that regulate these events are unclear. Because transforming growth factor-beta(1) (TGF-beta(1)) is a known fibrogenic cytokine, we hypothesized that the increased production of TGF-beta(1) would be associated with CVI disease progression. METHODS: Seventy-eight punch biopsy specimens of the lower calf (LC) and the lower thigh (LT) of 52 patients were snap frozen in liquid nitrogen and stratified into four groups according to the Society for Vascular Surgery/International Society for Cardiovascular Surgery CEAP classification (C, clinical; E, etiologic; A, anatomic distribution; and P, pathophysiology). One set of LC biopsy specimens were analyzed for TGF-beta(1) gene expression with quantitative reverse transcriptase-polymerase chain reaction: healthy skin, n = 6; class 4, n = 6; class 5, n = 5; and class 6, n = 7. A second set of biopsy specimens from the LC and LT were analyzed for the amount of bioactive TGF-beta(1) with a certified cell line 64 mink lung epithelial bioassay: healthy skin, n = 8; class 4, n = 23; class 5, n = 13; and class 6, n = 10. The location of TGF-beta(1) was determined at the light and electron microscopy level with immunocytochemistry and immunogold (IMG) labeling. Multiple comparisons were analyzed with a one-way analysis of variance and the Student-Newman-Keuls post hoc tests. The LC and LT comparisons were analyzed with a two-tailed unpaired t test. RESULTS: The TGF-beta(1) gene transcripts for control subjects and patients in classes 4, 5, and 6 were 7.02 +/- 7.33, 43.33 +/- 9.0, 16.13 +/- 7.67, and 7.22 +/- 0.56 x 10(-14) mol/microg total RNA, respectively. The transcripts were significantly elevated in class 4 patients only (P

Subject(s)
Dermis/pathology , Extracellular Matrix Proteins/genetics , Muscle, Smooth, Vascular/pathology , Transforming Growth Factor beta/genetics , Venous Insufficiency/pathology , Animals , Cell Line , Collagen/genetics , Disease Progression , Fibrosis , Gene Expression/genetics , Gene Expression/physiology , Humans , Immunohistochemistry , Mink , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic/genetics , Venous Insufficiency/genetics
20.
J Vasc Surg ; 30(5): 836-42, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10550181

ABSTRACT

OBJECTIVE: Clinical and microscopic evidence suggests the existence of sensory neuropathy in patients with severe chronic venous insufficiency (CVI). A clinical evaluation was conducted to determine whether a sensory neuropathy was present and, if so, to determine its extent and distribution. METHODS: The study was performed in a university-affiliated Veterans Affairs Medical Center. Twenty-three limbs were studied in 14 male veterans with mild or moderate CVI. The exclusions included diabetes, previous ipsilateral extremity surgery, or other diseases associated with neuropathy. Sensory thresholds in the limbs with CEAP class 2 disease (n = 11) were compared with the thresholds in the limbs with CEAP class 5 disease (n = 12) at nine different sites on the foot, ankle, calf, thigh, and palm. Thenar and hypothenar thresholds were measured as internal controls. Thresholds were determined by a pressure aesthesiometer consisting of 20 graduated filaments that ranged from 1.65 to 6.65 (log(10)mg)(10) of pressure. A complete, sensory motor assessment of the limb was performed by an experienced neurosurgeon who specialized in peripheral nerve evaluation. The clinical variables assessed were deep tendon reflexes, vibration, proprioception, and light touch. Venous reflux was determined with duplex ultrasound scanning and air plethysmography. RESULTS: Sensory thresholds at the most common site of venous ulceration-just proximal to the medial malleolus--were significantly (P <.05) different between mild (class 2) and severe (class 5) CVI. Sensory abnormalities coincided with the extent of trophic changes and did not reflect specific dermatomal or cutaneous nerve distributions. In addition to light touch or pinprick, vibration sense and deep tendon reflexes were also significantly worse in those with severe CVI. CONCLUSION: Sensory neuropathy is a feature of severe CVI, and its distribution is coincident with trophic changes. Because this is often unappreciated by the patient, it probably contributes to the propensity for deterioration from minor trauma.


Subject(s)
Peripheral Nervous System Diseases/etiology , Skin/innervation , Venous Insufficiency/complications , Arm/innervation , Humans , Leg/innervation , Male , Neurologic Examination , Peripheral Nervous System Diseases/diagnosis , Plethysmography , Sensory Thresholds , Ultrasonography, Doppler, Duplex , Venous Insufficiency/diagnostic imaging , Venous Insufficiency/physiopathology
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