Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Vasc Access ; : 11297298211045505, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524025

RESUMO

BACKGROUND: Quantitative physical examination (PE) indicators, including palpable pulsatility length and outflow scores, can be used to quantify stenosis severity at hemodialysis vascular access sites. It is known that the risk of high-shear-related thrombosis is increased when the minimal luminal diameter (MLD) of stenosis decreases. At present, MLD is measured using sonography or angiography. This study sought to determine the relationship between quantitative PE indicators and MLD and report their diagnostic performance in detecting patients with stenosis at a high risk of thrombosis. METHODS: We performed a retrospective case-control study using routinely collected data. We used the post-stenosis palpable pulsatility length (sPPL) and pulse-and-thrill based outflow score to assess the severity of AVF inflow and outflow stenosis, respectively. We recorded paired quantitative PE indicators and MLD before and after angioplasty in patients enrolled over a 4-month period. RESULTS: A total of 249 paired PE indicators and MLD measurements were obtained from 163 patients. A receiver operating characteristic curve analysis showed that an MLD cutoff value of <1.55 mm and an MLD of <1.95 mm discriminated sPPL = 0 and PESOS (physical examination significant outflow stenosis)/1- of the outflow score, respectively, from all other measurements, with the area under the curve values of 0.8922 and 0.9618, respectively. With sPPL = 0 and PESOS/1- of the outflow score as diagnostic tools to detect inflow stenosis with an MLD of ⩽1.5 mm and outflow stenosis with an MLD of ⩽1.9 mm at vascular access sites, sensitivity = 86.00% and 88.46%; specificity = 97.67% and 92.11%; positive predictive values of 97.73% and 92.00% and negative predictive values of 85.71% and 88.61%, respectively, were observed. CONCLUSIONS: Our preliminary results showed that physical examination can potentially be a diagnostic tool in detecting patients with stenosis who are at a high risk of thrombosis at hemodialysis vascular access sites with high diagnostic accuracy.

2.
BMC Nephrol ; 21(1): 304, 2020 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-32711458

RESUMO

BACKGROUND: Hyper-pulsatility of hemodialysis arteriovenous fistula (AVF) is the basic physical examination finding when there is outflow stenosis. The arm elevation test can also be utilized to detect outflow stenosis. If there is no significant outflow stenosis, the AVF should collapse, at least partially, because of the effect of gravity when the AVF-bearing arm is elevated to a level above that of the heart. However, if there is significant outflow stenosis, the portion of the AVF downstream of the stenosis will collapse, while the portion upstream of the stenosis will remain distended (Clin J Am Soc Nephro 8:1220-7, 2013). In our daily practice, when performing the arm elevation test, we not only observe the collapsibility of the access outflow but also palpate the outflow to identify a background thrill that sometimes disappears with the arm at rest, only to reappear when the arm is elevated. If there is no thrill upon arm elevation, we assume that the outflow stenosis is severe and refer to this condition as "physical examination significant outflow stenosis" (PESOS). The aim of this study is to characterize PESOS using percentage stenosis and Doppler flow parameters. METHODS: We performed a case-control study using data collected prospectively between June 2019 and December 2019. A pulse- and thrill-based score system was developed to assess the severity of AVF outflow stenosis. We recorded the outflow scores and Doppler measurements performed in 84 patients with mature fistulas over a 6-month period. Angiograms were reviewed to determine the severity of outflow stenosis, which was assessed by calculation of percentage stenosis. RESULTS: Receiver operating characteristic analysis showed that a cutoff value of ≥74.44% stenosis discriminated PESOS from other AVF outflow scores, with an area under the curve of 0.9011. PESOS diagnosed cases with ≥75% outflow stenosis in an AVF, with a sensitivity of 80.39%, a specificity of 78.79%, a positive predictive value of 85.42%, and a negative predictive value of 72.22%. CONCLUSIONS: PESOS can be used to diagnose ≥75% outflow stenosis in an AVF, with or without a significant collateral vein, and its diagnostic accuracy is high. The use of PESOS as an indicator for treatment implies that physical examination may represent a useful surveillance tool.

3.
AJR Am J Roentgenol ; 214(2): 477-481, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31743050

RESUMO

OBJECTIVE. The pipeline technique has been described for percutaneous creation of a long extraanatomic bypass for a thrombosed hemodialysis vascular access in patients with outflow veins that cannot be recanalized. However, when we used the pipeline technique in nonthrombotic vascular access sites to create a bypass to treat central venous occlusion, we encountered two technical challenges not mentioned in previous reports: bleeding from the peripheral incision and difficulty in pushing the stent-graft catheter through the subcutaneous track. CONCLUSION. We report our solutions for these two technical challenges and the treatment outcomes of percutaneous extraanatomic bypass for central venous occlusion in patients undergoing hemodialysis with access-related upper limb swelling.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Implante de Prótese Vascular/métodos , Cateterismo Venoso Central/efeitos adversos , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Idoso , Angiografia , Cateteres de Demora/efeitos adversos , Edema/etiologia , Edema/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Extremidade Superior/irrigação sanguínea , Grau de Desobstrução Vascular
4.
BMC Nephrol ; 20(1): 356, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519166

RESUMO

BACKGROUND: Pulsatility is an important property of hemodialysis arteriovenous fistulas (AVF) and can be perceived by the fingers as a gradual decrease in strength downstream from the anastomosis along the main trunk of the fistula. The distance from the point at which the pulse becomes imperceptible to the anastomosis is termed the palpable pulsatility length (PPL); we considered this length may play a role in assessing the severity of inflow stenosis for hemodialysis fistulas. METHODS: This study was performed by retrospective analysis of routinely collected data. Physical examinations and fistula measurements were performed in a selected population of 76 hemodialysis patients with mature fistulas during half a year. Fistula measurements included the PPL before and after treatment and the distance between the anastomosis and the arterial cannulation site (aPump length). The aPump index (API) was calculated by dividing the PPL by the aPump length. Angiograms were reviewed to determine the location and severity of stenosis. PPL and API were used to detect the critical inflow stenosis, which indicates severe inflow stenosis of an AVF. RESULTS: Receiver operating characteristic analysis showed that the area under the curve was 0.895 for API and 0.878 for PPL. A cutoff value of API < 1.29 and PPL < 11.0 cm were selected to detect the critical inflow stenosis. The sensitivity was 96.0% versus 80.0% and specificity was 84.31% versus 84.31% for API and PPL, respectively. CONCLUSIONS: PPL and API are useful tools in defining the severity of pure inflow stenosis for mature AVFs in the hands of trained examiners with high sensitivity and specificity.


Assuntos
Falha de Equipamento , Fluxo Pulsátil/fisiologia , Diálise Renal/efeitos adversos , Dispositivos de Acesso Vascular/efeitos adversos , Grau de Desobstrução Vascular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Constrição Patológica/diagnóstico , Constrição Patológica/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Renal/instrumentação , Estudos Retrospectivos
5.
J Vasc Access ; 19(6): 585-592, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29560785

RESUMO

PURPOSE:: This study was performed to retrospectively assess the efficacy of percutaneous creation of an intervascular bypass with or without stent graft deployment (endovascular bypass) for salvage of abandoned vascular access sites in hemodialysis catheter-consigned patients. METHODS:: Salvage of abandoned vascular access sites was attempted in 16 patients with hemodialysis catheters. These vascular access sites were salvaged using endovascular bypass techniques to redirect the access flow to a nonarterialized vein as a new outflow conduit or cannulation segment. The postintervention primary, assisted primary, and secondary patency rates of the access site and bypass were calculated using the Kaplan-Meier method. RESULTS:: The procedural and clinical success rates were both 100%. The postintervention primary patency rate of the bypass and access site at 360 days was 75.7 ± 12.5% and 56.8 ± 14.9%, respectively. The mean follow-up period was 461.9 days (range: 121-900 days). No major complications were observed. One bare bypass tunnel rupture and one pseudoaneurysm were noted during the procedure. CONCLUSION:: Salvage of abandoned vascular access sites for hemodialysis catheter-consigned patients can be technically feasible and clinically successful using endovascular bypass techniques in selected patients when surgical revision is not considered or is not possible.


Assuntos
Derivação Arteriovenosa Cirúrgica , Implante de Prótese Vascular , Cateterismo Venoso Central , Procedimentos Endovasculares , Diálise Renal , Terapia de Salvação/métodos , Idoso , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Prótese Vascular , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Masculino , Estudos Retrospectivos , Stents , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
6.
Radiol Case Rep ; 12(1): 108-112, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28228891

RESUMO

This study aimed to report a modification to the single-needle pass technique by use of a portal vein localization sheath for creation of a portosystemic shunt. The modification makes the single-needle pass technique a more straightforward procedure.

7.
Clin Neurol Neurosurg ; 145: 41-5, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27064861

RESUMO

OBJECTIVE: To determine if minimally invasive posterior interbody fusion with cortical bone trajectory (CBT) is associated with reduced paraspinal muscle damage compared to conventional open posterior lumbar interbody fusion (PLIF). METHODS: Sixteen consecutive patients who underwent CBT were grouped into matched pairs with 16 patients who underwent conventional PLIF between May 2013 and January 2014, in terms of age, sex, body mass index, and spinal levels. Perioperative data and clinical data, including the Japanese Orthopedics Association (JOA) score, visual analogue scale (VAS) score, Oswestry Disability Index (ODI),before and after surgery were evaluated. Magnetic resonance imaging was performed preoperatively and 6 months postoperatively. The fat infiltration ratio was calculated. RESULTS: Thirty-two patients with an 18-month follow-up period were evaluated. Clinical improvement, indicated by the VAS score for back and leg pain, ODI, and JOA score, was significant in both groups. However, there were no significant differences in operative time, blood loss, hospital stay duration, and recovery rate between the groups. The fat infiltration ratio was lower in the CBT group (p<0.05) than in the conventional PLIF group. CONCLUSIONS: CBT is comparable with conventional PLIF with respect to short-term clinical outcomes but induced less multifidus muscle damage.


Assuntos
Parafusos Ósseos , Atrofia Muscular/etiologia , Avaliação de Resultados em Cuidados de Saúde , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Idoso , Feminino , Humanos , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade
8.
J Vasc Access ; 17(1): 93-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26660035

RESUMO

PURPOSE: The purpose of this study is to describe a technique by which a bypass was created percutaneously with two overlapping covered stents for salvage of a thrombotic right brachial-axillary arteriovenous graft without recanalizable outflow. METHODS AND RESULTS: With the pipeline technique, a 16 cm bypass tract covered with two overlapping Viabahn stents between the hemodialysis graft and the right subclavian vein was created as an alternative access outflow. The hemodialysis graft was successfully salvaged without complications and functioned well for more than 6 months except for one thrombosis which occurred 147 days after its salvage. CONCLUSIONS: We describe an endovascular bypass technique using a sheath-dilator set and two angiographic catheters to salvage a thrombotic hemodialysis graft.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Implante de Prótese Vascular/efeitos adversos , Oclusão de Enxerto Vascular/cirurgia , Diálise Renal , Trombose/cirurgia , Extremidade Superior/irrigação sanguínea , Procedimentos Endovasculares/instrumentação , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Reoperação , Stents , Trombose/diagnóstico por imagem , Trombose/etiologia , Resultado do Tratamento , Dispositivos de Acesso Vascular , Grau de Desobstrução Vascular
9.
Cardiovasc Intervent Radiol ; 38(4): 894-902, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25476873

RESUMO

PURPOSE: This study aimed to retrospectively assess the efficacy of a bare intervascular tunnel for salvage of a thrombosed hemodialysis fistula. We examined the clinical outcomes and provided follow-up images of the bare intervascular tunnel. MATERIALS AND METHODS: Eight thrombosed fistulas lacked available recanalizable outflow veins were included in this study. These fistulas were salvaged by re-directing access site flow to a new outflow vein through a percutaneously created intervascular tunnel without stent graft placement. The post-intervention primary and secondary access patency rates were calculated using the Kaplan-Meier method. RESULTS: The procedural and clinical success rates were 100%. Post-intervention primary and secondary access patency at 300 days were 18.7 ± 15.8 and 87.5 ± 11.7%, respectively. The mean follow-up period was 218.7 days (range 10-368 days). One patient died of acute myocardial infarction 10 days after the procedure. No other major complications were observed. Minor complications, such as swelling, ecchymosis, and pain around the tunnel, occurred in all of the patients. CONCLUSIONS: Percutaneous creation of a bare intervascular tunnel is a treatment option for thrombosed hemodialysis fistulas without recanalizable outflow in selected patients.


Assuntos
Fístula Arteriovenosa/cirurgia , Oclusão de Enxerto Vascular/cirurgia , Falência Renal Crônica/complicações , Diálise Renal , Terapia de Salvação/métodos , Trombose/cirurgia , Idoso , Fístula Arteriovenosa/complicações , Feminino , Oclusão de Enxerto Vascular/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Trombose/complicações , Resultado do Tratamento , Grau de Desobstrução Vascular
10.
Psychiatry Res ; 211(2): 186-7, 2013 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-23394679

RESUMO

A diffusion tensor imaging (DTI) study was conducted in 12 adolescents with attention deficit/hyperactivity disorder and 14 age- and IQ-matched healthy controls. Inter-subject comparison of fractional anisotropy (FA) of the whole brain between the groups was obtained using the tract-based spatial statistics method. Results revealed significantly lower FA in widespread white matter tracts in cases relative to controls. Also, the FA measure of identified regions was associated with cognitive performance.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/patologia , Cognição , Fibras Nervosas Mielinizadas/patologia , Neuroimagem , Adolescente , Comportamento do Adolescente , Anisotropia , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Estudos de Casos e Controles , Humanos , Masculino
11.
Korean J Radiol ; 14(1): 70-80, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23323033

RESUMO

OBJECTIVE: The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses. MATERIALS AND METHODS: We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method. RESULTS: Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 ± 11.1% vs. 94.4 ± 5.4%; 33.3 ± 11.1% vs. 83.3 ± 8.8%; and 13.3 ± 8.5% vs. 63.3 ± 12.1%, respectively. CONCLUSION: Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.


Assuntos
Angioplastia com Balão/efeitos adversos , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Embucrilato/administração & dosagem , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Idoso , Falso Aneurisma/etiologia , Falso Aneurisma/terapia , Óleo Etiodado/administração & dosagem , Feminino , Oclusão de Enxerto Vascular/etiologia , Humanos , Masculino , Estudos Retrospectivos , Ruptura , Análise de Sobrevida , Resultado do Tratamento , Ultrassonografia de Intervenção , Grau de Desobstrução Vascular
12.
J Magn Reson Imaging ; 36(6): 1353-61, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23097197

RESUMO

PURPOSE: To demonstrate the presence of a multilayer appearance of the capsule on contrast-enhanced (CE) susceptibility-weighted imaging (SWI) in patients with pyogenic brain abscesses. Possible origins for the appearance and effects of postprocessing settings are discussed. MATERIALS AND METHODS: Fourteen patients with pyogenic brain abscesses underwent post gadolinium-enhanced SWI at 1.5 T. All SWI images were postprocessed with various filter and mask settings to compare the image appearance. Computer simulations using a paramagnetic spherical shell model were performed to verify the clinical findings. RESULTS: Pyogenic brain abscesses demonstrated a multilayer appearance with a darkened ring within the enhanced capsule on CE-SWI in all patients. The multilayer appearance was slice-orientation-dependent, decreased with larger widths of the high-pass filter, and increased with larger numbers of phase mask multiplication operations, consistently on both simulation results and the clinical images. CONCLUSION: CE-SWI shows the multilayer appearance of the capsule in pyogenic brain abscesses, which may arise from postprocessing procedures originally designed to enhance susceptibility contrast. Although SWI may provide additional information valuable in the diagnosis of pyogenic brain abscesses, image interpretation should be exercised with caution, particularly for CE-SWI.


Assuntos
Algoritmos , Abscesso Encefálico/patologia , Encéfalo/patologia , Gadolínio , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Meios de Contraste , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
13.
Clin Nucl Med ; 37(9): 899-900, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22889784

RESUMO

A 58-year-old woman presented with shuffling gait with small steps for 3 months. Tc-TRODAT-1 dopamine transporter SPECT/CT was prescribed to detect the function of the nigrostriatal system. It disclosed absence of uptake in the left putamen and diffusely decreased uptake in the right striatum. An unexpected mass with uneven uptake over the right frontal lobe was also noted. MRI demonstrated a large dura-related tumor, which was later proved as a meningioma after surgical intervention. Meningioma is the most common cause of tumor-induced parkinsonism. This case points to the significance of functional and structural fused neuroimaging in the evaluation of parkinsonism.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Achados Incidentais , Meningioma/diagnóstico por imagem , Imagem Multimodal , Compostos de Organotecnécio , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Tropanos , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Feminino , Humanos , Meningioma/metabolismo , Meningioma/patologia , Meningioma/fisiopatologia , Pessoa de Meia-Idade
14.
Cardiovasc Intervent Radiol ; 34(2): 319-30, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20585780

RESUMO

The current study retrospectively evaluated whether endovascular revascularization of chronically thrombosed and long-discarded vascular access sites for hemodialysis was feasible. Technical and clinical success rates, postintervention primary and secondary patency rates, and complications were reported. During a 1-year period, we reviewed a total of 924 interventions performed for dysfunction and/or failed hemodialysis vascular access sites and permanent catheters in 881 patients. In patients whose vascular access-site problems were considered untreatable or were considered treatable with a high risk of failure and access-site abandonment, we attempted to revascularize (resurrect) the chronically occluded and long-discarded (mummy) vascular access sites. We attempted to resurrect a total of 18 mummy access sites (mean age 46.6 ± 38.7 months; range 5-144) in 15 patients (8 women and 7 men; mean age 66.2 ± 11.5 years; age range 50-85) and had an overall technical success rate of 77.8%. Resurrection failure occurred in 3 fistulas and in 1 straight graft. The clinical success rate was 100% at 2 months after resurrection. In the 14 resurrected vascular access sites, 6 balloon-assisted maturation procedures were required in 5 fistulas; after access-site maturation, a total of 22 interventions were performed to maintain access-site patency. The mean go-through time for successful resurrection procedures was 146.6 ± 34.3 min (range 74-193). Postmaturation primary patency rates were 71.4 ± 12.1% at 30 days, 57.1 ± 13.2% at 60 days, 28.6 ± 13.4% at 90 days, and 19 ± 11.8% at 180 days. Postmaturation secondary patency rates were 100% at 30, 60, and 90 days and 81.8 ± 11.6% at 180 days. There were 2 major complications consisting of massive venous ruptures in 2 mummy access sites during balloon dilation; in both cases, prolonged balloon inflation failed to achieve hemostasis, but percutaneous N-butyl cyanoacrylate glue seal-off was performed successfully. Percutaneous resurrection of mummy vascular access sites for hemodialysis is technically feasible with high clinical success rates. In selected patients, resurrection of mummy access sites provides long-discarded access sites one more chance to be used for hemodialysis in an effort to preserve potential extremity sites for future access-site placement and to prevent long-term catheter indwelling.


Assuntos
Angioplastia com Balão/métodos , Fístula Arteriovenosa/terapia , Derivação Arteriovenosa Cirúrgica/métodos , Procedimentos Endovasculares/métodos , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Trombose/terapia , Idoso , Idoso de 80 Anos ou mais , Cateteres de Demora , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Grau de Desobstrução Vascular
16.
Korean J Radiol ; 11(3): 373-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20461194

RESUMO

Nutcracker syndrome occurs when the left renal vein (LRV) is compressed between the superior mesenteric artery and the aorta, and this syndrome is often characterized by venous hypertension and related pathologies. However, invasive studies such as phlebography and measuring the reno-caval pressure gradient should be performed to identify venous hypertension. Here we present a case of Nutcracker syndrome where the LRV and intra-renal varicosities appeared homogeneously hyperintense on magnetic resonance (MR) fast-spin-echo T2-weighted imaging, which suggested markedly stagnant intravenous blood flow and the presence of venous hypertension. The patient was diagnosed and treated without obtaining the reno-caval pressure gradient. The discomfort of the patient lessened after treatment. Furthermore, on follow-up evaluation, the LRV displayed a signal void, and this was suggestive of a restoration of the normal LRV flow and a decrease in LRV pressure.


Assuntos
Nefropatias/patologia , Imageamento por Ressonância Magnética/métodos , Veias Renais/patologia , Doenças Vasculares/patologia , Dor Abdominal/etiologia , Adulto , Constrição Patológica , Diagnóstico Diferencial , Seguimentos , Humanos , Nefropatias/complicações , Nefropatias/cirurgia , Masculino , Veias Renais/cirurgia , Stents , Síndrome , Doenças Vasculares/complicações , Doenças Vasculares/cirurgia , Adulto Jovem
17.
J Chin Med Assoc ; 73(3): 131-8, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20230997

RESUMO

BACKGROUND: To compare 3-dimensional gadolinium-enhanced elliptic centric-ordered (3D GEC) magnetic resonance venography (MRV) with traditional 2-dimensional time-of-flight (2D TOF) MRV for imaging of the intracranial venous system. METHODS: Fifty-three patients underwent 2D and 3D MRV, whereby venous structures were evaluated by 2 neuroradiologists. RESULTS: Of the 53 patients, 10 were diagnosed with dural venous sinus thrombosis and 12 with intracranial tumors. 3D GEC MRV displayed superior sensitivity/specificity (90.9%/96.8%) compared to 2D TOF MRV (63.6%/48.4%). Analysis of the areas under the receiver operating characteristic curves also showed superiority of 3D GEC (0.91) versus 2D TOF (0.53) MRV. Of the remaining 31 healthy patients, the rate of complete visibility of venous structures was also greater for 3D GEC (95.8%) than for 2D TOF (62.1%) MRV. CONCLUSION: 3D GEC MRV is superior to 2D TOF MRV for providing more detail of the intracranial venous system, and can lead to better diagnosis of venous conditions.


Assuntos
Veias Cerebrais/patologia , Gadolínio , Processamento de Imagem Assistida por Computador/métodos , Angiografia por Ressonância Magnética/métodos , Flebografia/métodos , Neoplasias Encefálicas/diagnóstico , Humanos , Imageamento Tridimensional/métodos , Sensibilidade e Especificidade , Trombose dos Seios Intracranianos/diagnóstico
18.
Cardiovasc Intervent Radiol ; 33(1): 67-73, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19572170

RESUMO

The purpose of this paper is to describe a unique "eighth note" deformity of the autogenous radiocephalic fistula for hemodialysis and to retrospectively evaluate the efficacy and safety of its endovascular treatment. Over 3 years, a total of 808 patients and 558 autogenous radiocephalic fistulas were treated for vascular access dysfunction or thrombosis. These included 14 fistulas in 14 patients (9 men, 5 women; mean age, 58.2 +/- 2.8 years; range 27-79 years) whose fistulograms before treatment resembled a musical note, the eighth note. Endovascular treatment sought to remodel the deformed vascular access to a classic radiocephalic fistula and increase the number of cannulation sites available for hemodialysis. The technical and clinical success rates were each 92.8% (13/14). Fistula remodeling was successful in 13 patients. The postintervention primary patency was 100% at 90 days, 91.7 +/- 0.8% at 120 days, 78.6 +/- 13.9% at 180 days, 62.9 +/- 17.9% at 360 days, 31.4 +/- 24.0% at 540 days, and 0% at 720 days. The postintervention secondary patency was 100% at 90 days, 100% at 120 days, 100% at 180 days, 85.7 +/- 13.2% at 360 days, and 85.7 +/- 13.2% at 720 days. No major complications were noted. Minor complications were found in 71.4% of patients, all of which resolved spontaneously. In conclusion, endovascular treatment of fistulas with the eighth note deformity can effectively increase the number of available cannulation sites, facilitate fistula maturation, and facilitate thromboaspiration after fistula thrombosis.


Assuntos
Angioplastia com Balão , Derivação Arteriovenosa Cirúrgica , Cateterismo Periférico/métodos , Fístula/terapia , Diálise Renal/métodos , Veias/anormalidades , Veias/cirurgia , Adulto , Idoso , Cateteres de Demora/efeitos adversos , Constrição Patológica/etiologia , Constrição Patológica/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Renal/efeitos adversos , Estudos Retrospectivos , Ultrassonografia , Grau de Desobstrução Vascular , Veias/diagnóstico por imagem
19.
J Chin Med Assoc ; 71(11): 587-93, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19015059

RESUMO

Pilocytic astrocytomas are found predominantly in the pediatric population; reports of these tumors are extremely rare in adults. We report 2 cases of adult pilocytic astrocytoma with intracranial hemorrhage. A 32-year-old male presented with neck stiffness and severe headache, and a 34-year-old male was referred for headache and double vision. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-enhanced and circumscribed cystic hemorrhagic tumor with mural nodule over the cerebral hemisphere region. Perfusion-weighted MRI (PWI) was also performed in both patients. The measured relative cerebral blood volume ratios of the mural nodules in these 2 cases were, respectively, 1.34 and 2.81 when compared with normal white matter. After surgical resection, microscopic examination of the lesions showed pilocytic astrocytomas. Since pilocytic astrocytoma and other cystic tumors with mural nodule (such as hemangioblastoma) have similar findings on conventional CT and MRI, PWI is helpful in the differential diagnosis. The literature on hemorrhagic pilocytic astrocytoma is also reviewed.


Assuntos
Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Hemorragia Cerebral/etiologia , Adulto , Astrocitoma/complicações , Neoplasias Encefálicas/complicações , Humanos , Masculino
20.
Surg Neurol ; 68 Suppl 1: S25-36, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17963918

RESUMO

BACKGROUND: The differential diagnosis of various intracranial cystic lesions is sometimes difficult on the basis of CT or MRI findings. Our objective was to evaluate (1)H MRS and DWI in the differential diagnosis of these lesions and in comparison with conventional MRI. METHODS: Fifty patients with intracranial cystic lesions (21 pyogenic abscesses, 23 tumor cysts, 3 epidermoid cysts, and 3 arachnoid cysts) were evaluated with conventional MRI, DWI, and in vivo (1)H MRS. Preoperative diagnosis of the lesions was based on the results of DWI and in vivo MRS. All DWI and (1)H MRS studies were performed with a clinical 1.5-T system. The DWI was performed using single-shot spin-echo echo-planar pulse sequence with b = 1000 s/mm(2). The ADC value was measured. Diagnostic accuracy of conventional MRI, DWI, and in vivo (1)H MRS was calculated with respect to a final diagnosis of brain abscess vs nonabscess cystic tumor. RESULTS: Lactate and cytosolic amino acids with/without succinate, acetate, and alanine were observed in 18 of 21 cases of abscesses on MRS. In 3 cases of epidermoid cysts, lactate was observed and could be differentiated from 3 cases of arachnoid cysts, which showed only minimal lactate. Only lactate was seen in 14 of 23 patients with tumor cysts, whereas both lipid/lactate and choline were visible in 9 patients with tumor cysts. Increased signal was seen in 20 of 21 patients with abscesses and 3 patients with epidermoid cysts on DWI. Decreased signal was observed in 22 of 23 patients with tumor cysts and 3 patients with arachnoid cyst on DWI. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of conventional MRI for the differentiation of brain abscess from nonabscess cystic tumor were 61.4%, 61.9%, 60.9%, 59.1%, and 63.6%, respectively, whereas they were 93.2%, 85.7%, 100%, 100%, and 88.5% with MRS; 95.5%, 95.2%, 95.7%, 95.2%, and 95.7% with DWI; and 97.7%, 95.2%, 100%, 100%, and 95.8% with MRS and DWI. Magnetic resonance imaging, when combined with in vivo MRS and DWI, accurately predicted the diagnosis in 47 (94%) of 50 and 48 (96%) of 50 of the cases, respectively. CONCLUSIONS: Proton MRS and DWI are useful as additional diagnostic modalities in differentiating intracranial cystic lesions. Combination of DWI with calculated ADC values and metabolite spectrum acquired by MRS add more information to MRI in the differentiation of intracranial cystic mass lesions.


Assuntos
Encefalopatias/diagnóstico , Encéfalo/patologia , Cistos do Sistema Nervoso Central/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Cistos Aracnóideos/diagnóstico , Cistos Aracnóideos/patologia , Cistos Aracnóideos/fisiopatologia , Biomarcadores/análise , Biomarcadores/metabolismo , Encéfalo/fisiopatologia , Abscesso Encefálico/diagnóstico , Abscesso Encefálico/patologia , Abscesso Encefálico/fisiopatologia , Encefalopatias/patologia , Encefalopatias/fisiopatologia , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Cistos do Sistema Nervoso Central/patologia , Cistos do Sistema Nervoso Central/fisiopatologia , Criança , Pré-Escolar , Diagnóstico Diferencial , Imagem de Difusão por Ressonância Magnética/normas , Cisto Epidérmico/diagnóstico , Cisto Epidérmico/patologia , Cisto Epidérmico/fisiopatologia , Feminino , Humanos , Espectroscopia de Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prótons , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...