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1.
J Laparoendosc Adv Surg Tech A ; 30(7): 737-741, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32412829

RESUMO

Background: Thoracic outlet syndrome (TOS) results from compression of neurovascular structures supplying the upper extremity as they exit the thoracic outlet. Depending on the clinical presentation, surgical decompression may be required. Objectives: Transaxillary (TA) and supraclavicular (SC) approaches are both widely utilized and deemed effective. Our objective was to review the outcomes for both approaches at our institution. Methods: A retrospective review was conducted on patients who underwent thoracic outlet decompression between 2010 and 2015. Data on demographics, comorbidities, presenting symptoms, and type of TOS (neurogenic, venous, or arterial) were collected. Operative times, length of hospital stay, perioperative complications, and outcomes were also studied. Results: A total of 82 thoracic outlet decompression procedures were performed during the study period: 42% neurogenic TOS, 46% venous TOS, and 12% arterial TOS. In total, 49% underwent TA approach and 51% underwent SC approach. Adjunct procedures were performed in 13% of patients. There were no significant differences in average operative time (151.3 ± 54.1 minutes versus 126.1 ± 36.1 minutes, P = .11) or hospital stay (2.3 ± 1.9 days versus 2.4 ± 1.4 days, P = .23) between both groups, respectively. Minor complications were seen in 6% of patients with no significant difference in both groups, whereas 6% had major complications. No perioperative or 30-day mortalities were observed. In total, 49% of patients had complete resolution of symptoms, 46% had partial improvement, and 5% had no improvement. There was no difference in symptom resolution between either group. Conclusions: TA and SC approaches are equally safe and effective for the treatment of TOS. SC decompression allows for adjunct procedures and vascular reconstructions.


Assuntos
Descompressão Cirúrgica/métodos , Costelas/cirurgia , Síndrome do Desfiladeiro Torácico/cirurgia , Adolescente , Adulto , Axila , Clavícula , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Síndrome do Desfiladeiro Torácico/diagnóstico , Síndrome do Desfiladeiro Torácico/etiologia , Resultado do Tratamento , Adulto Jovem
2.
Blood Coagul Fibrinolysis ; 29(6): 562-566, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30113416

RESUMO

: Recommended strategy for venous thromboembolism (VTE) diagnosis includes the use of sensitive D-dimer (DDi) assays along with pretest probability (PTP) assessment. The Clinical and Laboratory Standards Institute (CLSI) recently issued a guideline (US FDA endorsed) on DDi in VTE exclusion. Such guideline specifies the ideal D-dimer assay characteristics and target population. Demonstrate STA-LiatestD-Di performance combined with a PTP score for proximal deep vein thrombosis (pDVT) exclusion in a CLSI compliant study. International, multicenter, prospective nonrandomized, noninterventional clinical outcome management study conducted in a standard-of-care setting. DDi was measured in DVT-suspected consecutive low/moderate PTP outpatients, without conditions possibly impacting DDi values independently of thrombosis presence (age >80, pregnancy, postoperative, cancer) using a 0.5 µg/ml (FEU) threshold for DVT exclusion. Results were used to determine test performance. One thousand two hundred and thirty-four patients (17 centers) signed informed consent. Nine hundred and eighty (mean age: 55) with valid results (494 negative DDi) completed the study (DVT prevalence: 8.7%). STA-LiatestD-Di performance exceeded CLSI/FDA requirements: sensitivity: 100% (95% CI 95.8-100%), NPV: 100% (95% CI 99.3-100%). STA-LiatestD-Di associated with PTP score showed excellent performance for pDVT exclusion, as recently demonstrated for pulmonary embolism. The assay allows safe VTE exclusion, avoiding unnecessary imaging tests.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Imunoturbidimetria/métodos , Trombose Venosa/diagnóstico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais , Estudos Prospectivos , Sensibilidade e Especificidade , Estados Unidos , United States Food and Drug Administration , Trombose Venosa/sangue
3.
Vasc Endovascular Surg ; 47(1): 42-4, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23090841

RESUMO

Perigraft hygroma is a known complication of prosthetic graft implantation. The specific etiology of perigraft hygromas is still unknown. We report 2 brothers who underwent open abdominal aortic aneurysm repairs with polytetrafluoroethylene grafts that developed progressively enlarging perigraft hygromas. This is the first case report of 2 brothers developing sac hygromas after open abdominal aortic aneurysm repair. This case demonstrates that there could be a genetic component associated with the development of perigraft hygromas and further investigation of genetic etiologies should be considered.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Linfangioma Cístico/genética , Neoplasias Vasculares/genética , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Ruptura Aórtica/diagnóstico por imagem , Aortografia/métodos , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/instrumentação , Predisposição Genética para Doença , Humanos , Linfangioma Cístico/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Politetrafluoretileno , Desenho de Prótese , Tomografia Computadorizada por Raios X , Neoplasias Vasculares/diagnóstico por imagem
4.
Circ Cardiovasc Interv ; 5(6): 821-30, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23192920

RESUMO

BACKGROUND: Critical limb ischemia portends a risk of major amputation of 25% to 35% within 1 year of diagnosis. Preclinical studies provide evidence that intramuscular injection of autologous CD34+ cells improves limb perfusion and reduces amputation risk. In this randomized, double-blind, placebo-controlled pilot study, we evaluated the safety and efficacy of intramuscular injections of autologous CD34+ cells in subjects with moderate or high-risk critical limb ischemia, who were poor or noncandidates for surgical or percutaneous revascularization (ACT34-CLI). METHODS AND RESULTS: Twenty-eight critical limb ischemia subjects were randomized and treated: 7 to 1 × 10(5) (low-dose) and 9 to 1 × 10(6) (high-dose) autologous CD34+ cells/kg; and 12 to placebo (control). Intramuscular injections were distributed into 8 sites within the ischemic lower extremity. At 6 months postinjection, 67% of control subjects experienced a major or minor amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.137). This trend continued at 12 months, with 75% of control subjects experiencing any amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.058). Amputation incidence was lower in the combined cell-treated groups compared with control group (6 months: P=0.125; 12 months: P=0.054), with the low-dose and high-dose groups individually showing trends toward improved amputation-free survival at 6 months and 12 months. No adverse safety signal was associated with cell administration. CONCLUSIONS: This study provides evidence that intramuscular administration of autologous CD34+ cells was safe in this patient population. Favorable trends toward reduced amputation rates in cell-treated versus control subjects were observed. These findings warrant further exploration in later-phase clinical trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00616980.


Assuntos
Antígenos CD34/análise , Isquemia/cirurgia , Extremidade Inferior/irrigação sanguínea , Transplante de Células-Tronco , Células-Tronco/imunologia , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Análise de Variância , Biomarcadores/análise , Estado Terminal , Intervalo Livre de Doença , Método Duplo-Cego , Feminino , Humanos , Injeções Intramusculares , Isquemia/fisiopatologia , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Qualidade de Vida , Recuperação de Função Fisiológica , Transplante de Células-Tronco/efeitos adversos , Fatores de Tempo , Transplante Autólogo , Resultado do Tratamento , Estados Unidos , Cicatrização
5.
J Vasc Surg ; 54(5): 1478-80, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21723067

RESUMO

A 56-year-old man with a family history of aortic aneurysm underwent routine repair in 2003. A postoperative computed tomography scan showed a 6-cm perigraft hygroma. Sudden onset of abdominal pain 12 months later revealed a larger hygroma, with an additional anterior fluid collection suggestive of contained rupture. The bilobed hygroma remained stable until 2010, when he presented with chills and severe abdominal pain. A computed tomography scan demonstrated free rupture of the sister hygroma, with air pockets observed within the sac. Conservative management was elected. Air pockets as well as the hygroma eventually resolved, and the patient remains well.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular/efeitos adversos , Linfangioma Cístico/etiologia , Neoplasias Vasculares/etiologia , Dor Abdominal/etiologia , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Ruptura Aórtica/diagnóstico por imagem , Aortografia/métodos , Descompressão Cirúrgica , Humanos , Linfangioma Cístico/diagnóstico por imagem , Linfangioma Cístico/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Regressão Neoplásica Espontânea , Ruptura Espontânea , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Neoplasias Vasculares/diagnóstico por imagem , Neoplasias Vasculares/cirurgia
6.
Vasc Endovascular Surg ; 45(3): 274-82, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21478247

RESUMO

PURPOSE: Describe a hybrid approach to simplify management of complex aortoiliac occlusive disease (AIOD) extending into the common femoral artery (CFA). METHODS: Retrospective review of 56 patients who underwent hybrid management of AIOD extending into CFA between January 2003 and February 2007. Two distinct hybrid approaches were compared: Inline (iliac stenting continuous with an open CFA reconstruction, 38 limbs in 37 patients) and tandem (noncontiguous stenting of an upstream iliac segment, 20 limbs in 19 patients). The median follow-up duration was 15 ± 12 months in the inline group and 24 ± 12 months in the tandem group. RESULTS: Technical success was achieved in all but 1 procedure. Clinical and hemodynamic responses to the interventions and limb loss rates were comparable in both groups. Survival table analysis showed no significant difference between inline and tandem reconstructions. CONCLUSIONS: Inline stenting represents a lesser invasive revascularization choice in complex AIOD with contiguous involvement of the CFA.


Assuntos
Doenças da Aorta/cirurgia , Arteriopatias Oclusivas/cirurgia , Procedimentos Endovasculares/instrumentação , Artéria Femoral/cirurgia , Artéria Ilíaca/cirurgia , Stents , Procedimentos Cirúrgicos Vasculares , Adulto , Idoso , Amputação Cirúrgica , Doenças da Aorta/mortalidade , Doenças da Aorta/fisiopatologia , Arteriopatias Oclusivas/mortalidade , Arteriopatias Oclusivas/fisiopatologia , Distribuição de Qui-Quadrado , Terapia Combinada , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Artéria Femoral/fisiopatologia , Hemodinâmica , Humanos , Artéria Ilíaca/fisiopatologia , Iowa , Estimativa de Kaplan-Meier , Salvamento de Membro , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Procedimentos Cirúrgicos Vasculares/mortalidade
7.
Vasc Endovascular Surg ; 44(6): 460-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20484077

RESUMO

PURPOSE: To report experience with aggressive recanalization approaches in chronic total arterial occlusion (CTO). METHODS: Chronic total arterial occlusion recanalization was attempted on 112 limbs in 99 consecutive patients between January 1999 and December 2006. RESULTS: There were 63 iliac arteries, 45 femoropopliteal arteries, and 4 occluded stents. Mean occlusion length was 8.7 ± 4.7 cm. Conventional recanalization was attempted first and was successful in 71 limbs (70%). Probing with the guidewire's stiff end was attempted in 33 of the 41 procedures where conventional techniques failed and was successful in 18 (54%), improving the overall procedural success rate to 80%. For the remaining 15 limbs, home-made directional sharp needle recanalization was attempted in 11 and was successful in 9 (82%), further improving the overall recanalization success to 88%. Procedural complications were self-limited or managed nonoperatively. CONCLUSIONS: Aggressive recanalization techniques in CTO following failure of traditional means are safe and can substantially improve procedural success rates.


Assuntos
Angioplastia com Balão , Arteriopatias Oclusivas/terapia , Procedimentos Endovasculares , Artéria Femoral , Artéria Ilíaca , Artéria Poplítea , Idoso , Angioplastia com Balão/efeitos adversos , Angioplastia com Balão/instrumentação , Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/fisiopatologia , Distribuição de Qui-Quadrado , Doença Crônica , Constrição Patológica , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Desenho de Equipamento , Feminino , Artéria Femoral/fisiopatologia , Humanos , Artéria Ilíaca/fisiopatologia , Iowa , Estimativa de Kaplan-Meier , Modelos Logísticos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Artéria Poplítea/fisiopatologia , Radiografia Intervencionista , Estudos Retrospectivos , Stents , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
8.
J Xray Sci Technol ; 18(1): 15-25, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20421701

RESUMO

Computed Tomography (CT) has become an effective diagnosis and evaluating tool in clinical; however, its radiation exposure has drawn great attention as more and more CT scans are performed every year. How to reduce the radiation dose and meanwhile keep the resultant CT images diagnosable becomes an important research topic. In this paper, we propose a dose reduction approach along with the adaptive bolus chasing CT Angiography (CTA) techniques, which are capable of tracking the contrast bolus peak over all the blood vessel segments during the CTA scan. By modulating the tube current (and collimator width) online, we can reduce the total radiation dose and maintain the contrast to noise ratio (CNR) of the blood vessel. Numerical experiments on reference DSA data sets show that by using the proposed dose reduction method, the effective radiation dose can be saved about 39%.


Assuntos
Angiografia Digital/métodos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Simulação por Computador , Relação Dose-Resposta à Radiação , Humanos , Doenças Vasculares/diagnóstico
10.
Ann Vasc Surg ; 22(3): 346-57, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18411026

RESUMO

We assessed the long-term patency of kissing stent reconstruction of the aortoiliac bifurcation and identified variables that may influence it. We retrospectively reviewed our experience with stent-reconstruction procedures of the aortoiliac bifurcation from January 1998 through June 2005. The impact of demographic variables, vascular risk factors, disease location and characteristics, stent material and design, and stenting configuration on stent patency was assessed using univariate and multivariate analysis. In particular, we evaluated the effect of geometric mismatch between the protruding segment of the stents and the distal aortic lumen. Sixty-six patients underwent aortobi-iliac stent reconstruction. Indications were bifurcation or bilateral proximal iliac disease in 52 patients and unilateral ostial disease requiring contralateral protection in 14 patients. Limited disease (TASC A and B) was present in 40 limbs in 19 patients; extensive/diffuse disease (TASC C and D) was present in 78 limbs in 47 patients. Complete occlusions were present in 37 limbs in 28 patients (bilateral in nine patients). Self-expanding stents were used in 56 procedures and balloon-expandable stents in 10. Crossing configuration was used in 43 procedures, while abutting configuration was used in 23 procedures. Technical success was achieved in 62 patients (94%), with all four failures due to inability to cross a chronically occluded limb. Three of these patients underwent aortomono-iliac stenting with a crossover femoral-femoral bypass graft, with the remaining one opting for no further interventions. Median combined follow-up was 37 +/- 27 months (range 0-102). Hemodynamically significant restenosis developed in nine patients (14%). The management of restenosis was endovascular in eight patients and was successful in all (balloon dilation in four, restenting in three, thrombolysis and stenting in one) and operative in one patient who developed aortic occlusion and underwent aortobifemoral grafting. Survival table analysis showed primary and assisted patency rates at 4 years of 81% and 94%, respectively. The mortality rate during follow-up was 19 (cardiac cause in eight, pulmonary cause in three, and malignancy in five). Univariate analysis showed radial mismatch (aortic lumen dead space around the protruding segment of the stents), female gender, prior occlusion, and residual stenosis to be significant predictors of restenosis. Multivariate logistic regression analysis showed radial mismatch to be the only significant determinant of restenosis, although the statistical power of the model was limited by the small number of restenoses. Stent reconstruction of the aortoiliac bifurcation for occlusive disease is effective and durable, even with complex aortoiliac disease and long segment occlusions. Most restenoses are amenable to endovascular treatment, with excellent long-term assisted patency. Geometric variables related to individual aortic anatomy and disease pattern (patient-dependent) and stenting configuration (operator-dependent) may have an impact on long-term patency.


Assuntos
Angioplastia/instrumentação , Aorta/cirurgia , Doenças da Aorta/cirurgia , Arteriopatias Oclusivas/cirurgia , Artéria Ilíaca/cirurgia , Stents , Idoso , Idoso de 80 Anos ou mais , Angioplastia/efeitos adversos , Aorta/patologia , Aorta/fisiopatologia , Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/mortalidade , Doenças da Aorta/fisiopatologia , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/mortalidade , Arteriopatias Oclusivas/fisiopatologia , Constrição Patológica , Feminino , Seguimentos , Humanos , Artéria Ilíaca/diagnóstico por imagem , Artéria Ilíaca/fisiopatologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Desenho de Prótese , Radiografia , Recidiva , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
11.
Ann Vasc Surg ; 22(3): 358-65, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18411033

RESUMO

There has been widespread initial enthusiasm for peripheral atherectomy using the SilverHawk device. We sought to evaluate our midterm patency following infrainguinal atherectomy. Nineteen consecutive patients underwent 23 separate atherectomy procedures on 20 limbs from March 2005 through June 2006 (11 males, age 66 +/- 14 years). The primary lesions were atherosclerotic (n = 18) and vein graft stenoses (n = 2). Three additional procedures were redo atherectomies for restenotic lesions. The TASC classification of the primary lesions was A in 3, B in 9, and C in 8. The median number of treated lesions per limb was 2 (range 1-4). The location of the most distal native vessel stenosis was the superficial femoral artery in 12, popliteal artery in six, and crural artery in two. Atherectomy was successful in 18 primary procedures and all three repeat atherectomy procedures. Touch-up balloon dilatation was used in five procedures. Complications included one groin hematoma and two perforations, treated with stenting in one and bypass grafting in one. Preoperative ankle-brachial index and transmetatarsal pulse volume recording were 0.51 +/- 0.16 and 3.3 +/- 0.8, respectively, which at 1-month improved to 0.80 +/- 0.16 and 2.4 +/- 0.4 (p < 0.001). Only two vessels remained patent at 12 months. Recurrence developed in 16 of the successful primary procedures, including both vein graft lesions and all three repeat atherectomy procedures. The mode of recurrence was restenosis in 14 and occlusion/thrombosis in five. Secondary interventions included balloon angioplasty/thrombolysis in two, stenting in three, redo atherectomy in three, vein bypass grafting in five, and observation alone in one. Major limb amputation was required in five patients. Primary patency rates per treated limb at 3, 6, and 12 months were 38%, 10%, and 10%. The corresponding assisted patency rates were 50%, 23%, and 10%. Our experience suggests a very poor midterm patency of excisonal atherectomy using the SilverHawk device, although a 74% limb salvage rate was maintained through secondary interventions. Liberal use of this technology is associated with high cost and frequent requirement of reintervention.


Assuntos
Arteriopatias Oclusivas/cirurgia , Aterectomia , Extremidades/irrigação sanguínea , Grau de Desobstrução Vascular , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Angioplastia com Balão/instrumentação , Tornozelo/irrigação sanguínea , Arteriopatias Oclusivas/fisiopatologia , Aterectomia/efeitos adversos , Aterectomia/instrumentação , Pressão Sanguínea , Artéria Braquial/fisiopatologia , Constrição Patológica , Desenho de Equipamento , Feminino , Seguimentos , Humanos , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Estudos Retrospectivos , Índice de Gravidade de Doença , Stents , Terapia Trombolítica , Fatores de Tempo , Resultado do Tratamento , Veias/transplante
12.
Perspect Vasc Surg Endovasc Ther ; 20(1): 50-60, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18388012

RESUMO

Kissing stent reconstruction of the aortoiliac bifurcation is a widely used technique for the management of aortoiliac occlusive disease involving the aortic bifurcation or proximal common iliac arteries. New advances in delivery systems and stent design have enabled better anatomic results with kissing stenting. Long-term patency is generally excellent, although several factors may adversely affect patency and should be taken into account when devising the stenting configuration and selecting the device to be used. Geometric variables related to individual aortic anatomy and disease pattern (patient dependent) and stenting configuration (operator dependent) may have an impact on long-term patency. Kissing stent aortoiliac reconstruction is effective and durable, even with complex aortoiliac disease and long-segment occlusions. In our experience, TASC (TransAtlantic Inter-Society Consensus) C and D class disease is not necessarily a contraindication to aortoiliac stent reconstruction, especially in poor operative risk patients. Most restenoses are amenable to endovascular treatment, with excellent long-term assisted patency.


Assuntos
Arteriopatias Oclusivas/cirurgia , Implantação de Prótese/métodos , Stents , Arteriopatias Oclusivas/classificação , Aterosclerose/cirurgia , Contraindicações , Feminino , Humanos , Claudicação Intermitente/cirurgia , Pessoa de Meia-Idade , Desenho de Prótese , Grau de Desobstrução Vascular
13.
Biomed Signal Process Control ; 3(4): 319-326, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19802329

RESUMO

In this paper, a new adaptive bolus-chasing control scheme is proposed to synchronize the bolus peak in a patient's vascular system and the imaging aperture of a computed tomography (CT) scanner. The proposed control scheme is theoretically evaluated and experimentally tested on a modified Siemens SOMATOM Volume Zoom CT scanner. The first set of experimental results are reported on bolus-chasing CT angiography using realistic bolus dynamics, real-time CT imaging and adaptive table control with physical vasculature phantoms. The data demonstrate that the proposed control approach tracks the bolus propagation well, and clearly outperforms the constant-speed scheme that is the current clinical standard.

14.
Biomed Eng Online ; 5: 53, 2006 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-17044929

RESUMO

BACKGROUND: A detailed contrast bolus propagation model is essential for optimizing bolus-chasing Computed Tomography Angiography (CTA). Bolus characteristics were studied using bolus-timing datasets from Magnetic Resonance Angiography (MRA) for adaptive controller design and validation. METHODS: MRA bolus-timing datasets of the aorta in thirty patients were analyzed by a program developed with MATLAB. Bolus characteristics, such as peak position, dispersion and bolus velocity, were studied. The bolus profile was fit to a convolution function, which would serve as a mathematical model of bolus propagation in future controller design. RESULTS: The maximum speed of the bolus in the aorta ranged from 5-13 cm/s and the dwell time ranged from 7-13 seconds. Bolus characteristics were well described by the proposed propagation model, which included the exact functional relationships between the parameters and aortic location. CONCLUSION: The convolution function describes bolus dynamics reasonably well and could be used to implement the adaptive controller design.


Assuntos
Meios de Contraste , Doenças das Valvas Cardíacas/diagnóstico , Interpretação de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética/métodos , Modelos Cardiovasculares , Simulação por Computador , Humanos , Estudos Retrospectivos
15.
J Comput Assist Tomogr ; 30(5): 846-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16954941

RESUMO

Computed tomographic (CT) angiography is important for imaging studies on cardiovascular structures, peripheral vessels, and solid organs. In practice, a CT angiography scan is triggered by the bolus arrival at a prespecified anatomical location, which is determined using CT fluoroscopy. In this article, we propose a projection-based method adapted from the Grangeat formula to detect the bolus arrival. Then, we evaluate our new method in numerical and animal studies. Our results indicate that this method allows significantly better temporal resolution and is computationally more efficient, as compared with the image-based methods.


Assuntos
Meios de Contraste , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Angiografia/métodos , Animais , Fluoroscopia/métodos , Pulmão/diagnóstico por imagem , Modelos Teóricos , Intensificação de Imagem Radiográfica/métodos , Ovinos , Fatores de Tempo
16.
J Xray Sci Technol ; 14(1): 27-38, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-27034539

RESUMO

To improve imaging quality and to reduce contrast dose and radiation exposure, an adaptive bolus chasing CT angiography was proposed so that the bolus peak position and the imaging aperture can be synchronized. The performance of the proposed adaptive bolus chasing CT angiography was experimentally evaluated based on the actual bolus dynamics. The experimental results show that the controlled table position and the bolus peak position were highly consistent. The results clearly demonstrate that the proposed adaptive bolus chasing CT angiography that synchronizes the bolus peak position with the imaging aperture by a simple adaptive system is computationally and clinically feasible. Similar techniques may also be applied to conventional angiography to improve imaging quality and to reduce contrast dose and/or radiation exposure.

17.
Kidney Int ; 68(5): 2352-61, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16221240

RESUMO

BACKGROUND: Regular access monitoring is recommended to detect and treat access stenosis in order to prevent access thrombosis and failure. METHODS: In 1999, we instituted monthly access blood flow monitoring using the ultrasound dilution technique (UDT). In a sequential observational trial, 222 patients were studied for the impact of UDT monitoring on patency of their first arteriovenous autogenous fistula. Group 1, the historic group (before 1999), had 146 arteriovenous fistulas (50.7% upper arm), followed for 259 access-years. Group 2, the UDT-monitored group, had 76 arteriovenous fistulas (60.5% upper arm), followed for 123 access-years. Decision to refer for angiography was based on clinical criteria for group 1, and clinical criteria plus results of UDT flow monitoring in group 2. RESULTS: Cumulative patency was longer (P < 0.01) and the thrombosis rate was lower (P < 0.05) in group 2. However, the improvement occurred prior to initiation of UDT flow monitoring. Comparing outcomes in group 2 patients whose fistula survived to start flow monitoring with group 1 patients whose fistula survived at least 160 days (the median time to starting UDT monitoring in group 2), there was a sevenfold increase in angioplasty procedures (0.67 vs. 0.09 per access-year) but no improvement in the thrombosis rate or cumulative fistula patency. CONCLUSION: UDT monitoring increased the rate of angioplasty procedures and thereby shortened primary unassisted patency, but did not decrease the thrombosis rate or improve cumulative fistula patency.


Assuntos
Angioplastia/estatística & dados numéricos , Derivação Arteriovenosa Cirúrgica , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/prevenção & controle , Falência Renal Crônica/terapia , Bases de Dados Factuais , Humanos , Estudos Longitudinais , Modelos de Riscos Proporcionais , Fluxo Sanguíneo Regional , Diálise Renal , Trombose/diagnóstico por imagem , Trombose/prevenção & controle , Ultrassonografia , Grau de Desobstrução Vascular
18.
Radiology ; 236(3): 825-33, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16020554

RESUMO

PURPOSE: To evaluate prospectively the safety and effectiveness of aortoiliac magnetic resonance (MR) angiography enhanced with MS-325 (gadofosveset trisodium) at a dose of 0.03 mmol/kg; effectiveness was defined as accuracy relative to the reference standard, conventional angiography. MATERIALS AND METHODS: Study was approved by institutional review boards of participating institutions, and required national approvals were obtained. Study protocol conformed to Good Clinical Practice guidelines, and informed patient consent was obtained. Patients with known or suspected peripheral vascular disease received 0.03 mmol/kg MS-325 for aortoiliac MR angiography. They were also examined with conventional angiography. MS-325-enhanced MR was evaluated for safety and effectiveness. Along with unenhanced two-dimensional time-of-flight MR angiography, it was compared with conventional angiography for presence of vascular stenosis. Student t tests were used to identify significant improvement in diagnostic sensitivity, specificity, and accuracy, as well as quantitative characterization of stenoses by three blinded readers. Correlations between readers of conventional angiograms were calculated and compared with MR results. RESULTS: In 174 patients, MS-325-enhanced MR angiography showed significant improvement (P < or = .001) in sensitivity, specificity, and accuracy for diagnosis of clinically significant (> or =50%) stenosis, compared with unenhanced MR. For all readers, areas under the receiver operating characteristic curve for both quantitative and qualitative measures of significant disease increased (P < .001) for MS-325-enhanced MR compared with time-of-flight MR. All readers also expressed higher confidence in diagnosis (P < .001) and found fewer images uninterpretable with MS-325 enhancement. All measures of interpretation accuracy approached corresponding measures of correlation between readers of conventional angiograms. Incidence of severe and serious adverse events with MS-325 was low. No patients were withdrawn from study due to adverse events or abnormalities in laboratory results. There were no clinically important trends in findings at hematology, blood chemistry, urinalysis, electrocardiography, or physical examination. CONCLUSION: MR angiography with MS-325 provides significant improvement in effectiveness over unenhanced MR (and minimal and transient side effects) at a dose of 0.03 mmol/kg and was safe and effective for MR evaluation of patients with aortoiliac occlusive disease.


Assuntos
Doenças da Aorta/diagnóstico , Arteriopatias Oclusivas/diagnóstico , Artéria Ilíaca , Angiografia por Ressonância Magnética/métodos , Compostos Organometálicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Meios de Contraste , Feminino , Gadolínio , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade
19.
J Vasc Surg ; 38(4): 692-8, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14560214

RESUMO

PURPOSE: To evaluate the safety and assess the role of endovascular therapy in a variety of conditions related to celiac and mesenteric vascular occlusive disease. Patients and methods Our retrospective study population included 25 consecutive patients (mean age, 66 years), in whom 28 procedures were performed on 26 stenosed or occluded mesenteric vessels (superior mesenteric artery [SMA] or celiac artery [CA]). Indications included chronic mesenteric ischemia (21 patients), including 2 patients who underwent stenting prior to a planned operative repair of a juxtamesenteric AAA. Three liver transplantation patients underwent stenting of an associated CA stenosis. One patient with a splenorenal bypass underwent stenting on an associated CA stenosis. The technical and clinical success rates and the incidence of complications were determined. Follow-up parameters included maintained patency on duplex sonography and sustained clinical benefit. The need for additional interventions was noted. RESULTS: All procedures but one were technically successful (96%). Major complications occurred in three patients (one transient contrast-induced nephrotoxicity and two pseudoaneurysms). Immediate clinical success was achieved in 22 patients (88%). The three clinical failures included two patients with an excellent angiographic outcome, but with single-vessel moderate severity disease. Survival table analysis of delayed clinical outcome showed primary and primary-assisted clinical benefits at 11 months of 85% and 91%, respectively. Primary and primary-assisted stent patencies, as assessed by duplex sonography and/or angiography, at 6 months were both 92%. Angiographically documented restenosis occurred in three patients. Restenosis in two patients with CA stents was due to extrinsic compression, and it was without symptoms in one patient and was treated satisfactorily by restenting in the other patient. Restenosis in one patient with an SMA stent was successfully treated by restenting. CONCLUSIONS: Our experience suggests a potential role for endovascular therapy of celiac and mesenteric arterial occlusive disease in a variety of clinical scenarios, with a low incidence of complications and a high technical success rate.


Assuntos
Artéria Celíaca/cirurgia , Artérias Mesentéricas/cirurgia , Oclusão Vascular Mesentérica/cirurgia , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia com Balão , Constrição Patológica/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Grau de Desobstrução Vascular
20.
J Vasc Interv Radiol ; 14(4): 405-23, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12682198

RESUMO

Acute complications of deep vein thrombosis (DVT) of the lower extremities include pulmonary embolism and venous ischemia. Delayed complications include a spectrum of debilitating symptoms referred to as postthrombotic syndrome (PST). Anticoagulation therapy is recognized as the mainstay of therapy in acute DVT. However, there are few data to suggest any major beneficial effect on PTS, which is thought to be mediated by valve damage and/or occlusive chronic thrombus and venous scarring. Endovascular catheter-directed thrombolysis techniques with pharmacologic thrombolytic agents, used alone or in combination with mechanical thrombectomy devices, have been proven highly effective in clearing acute DVT, which may allow the preservation of venous valve function and prevention of subsequent venous occlusive disease. Definitive management of underlying anatomic occlusive abnormalities can also be undertaken.


Assuntos
Arteriopatias Oclusivas/terapia , Extremidade Inferior/irrigação sanguínea , Extremidade Inferior/patologia , Trombose Venosa/terapia , Arteriopatias Oclusivas/epidemiologia , Arteriopatias Oclusivas/patologia , Gerenciamento Clínico , Humanos , Incidência , Embolia Pulmonar/epidemiologia , Embolia Pulmonar/patologia , Embolia Pulmonar/terapia , Fatores de Risco , Estados Unidos/epidemiologia , Trombose Venosa/epidemiologia , Trombose Venosa/patologia
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