RESUMO
Axillary web syndrome (AWS) is a common condition occurring in up to 86% of patients following breast cancer surgery with ipsilateral lymphadenectomy of one or more nodes. AWS presents as a single cord or multiple thin cords in the subcutaneous tissues of the ipsilateral axilla. The cords may extend variable distances "down" the ipsilateral arm and/or chest wall. The cords frequently result in painful shoulder abduction and limited shoulder range of motion. AWS most frequently becomes symptomatic between 2 and 8 weeks postoperatively but can also develop and recur months to years after surgery. Education about and increased awareness of AWS should be promoted for patients and caregivers. Assessments for AWS should be performed on a regular basis following breast cancer surgery especially if there has been associated lymphadenectomy. Physical therapy, which consists of manual therapy, exercise, education, and other rehabilitation modalities to improve range of motion and decrease pain, is recommended in the treatment of AWS.
RESUMO
Axillary web syndrome (AWS) is a frequently overlooked problem that causes morbidity in the early post-operative period following cancer surgery with axillary lymph node removal (1-3). AWS, also known as "cording" was first described in 2001 by Moskovitz as "a visible web of axillary skin overlying palpable cords of tissue that are made taut by shoulder abduction" (1). Over a decade has passed since Moskovitz's seminal article was published, and we still lack a good understanding of AWS. This condition has been suboptimally studied using widely differing criteria. This has resulted in almost meaningless data such as the incidence of the problem, which varies from 6 to 72% following cancer surgery with axillary lymph node dissection (ALND) or sentinel node biopsy (SNB) (1-5). AWS continues to perplex the medical and scientific community. For instance, there is no explanation for the observation that individuals with a lower body mass index (BMI) are at higher risk for AWS (1-3). There are differing views on the physiological and etiological aspects of AWS. Some believe there is a vascular component involving the lymphatic and/or venous system (1, 6-11). Others consider the cord to be composed of fascial tissue (12). The terminology used to describe the cord varies dependent on the researcher's opinions, which are based on their speculations as to the underlying pathophysiology of the condition. The purpose of this paper is to present a new perspective that supports the theory that AWS is associated with the lymphatic system.Based on our clinical experience including more in-depth analysis of specific cases, our clinical research, and the accumulated literature, we present our proposal to explain the pathophysiology of AWS, define the period of onset and duration of AWS, outline possible reasons for the association between AWS and BMI, and postulate why we occasionally see cases of AWS that are associated with conditions that disturb normal lymphatic function but are unrelated to surgery.
Assuntos
Axila/cirurgia , Neoplasias da Mama/cirurgia , Exercício Físico , Excisão de Linfonodo , Doenças Linfáticas/fisiopatologia , Sistema Linfático/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Biópsia de Linfonodo Sentinela , Índice de Massa Corporal , Humanos , Incidência , Doenças Linfáticas/epidemiologia , Vasos Linfáticos , Neoplasias/cirurgia , Complicações Pós-Operatórias/epidemiologia , Fatores de Proteção , Fatores de Risco , SíndromeRESUMO
The aim of this study was to determine if ultrasound could successfully characterize axillary web syndrome (AWS) and clarify the pathophysiologic basis of AWS as a vascular or lymphatic abnormality, or an abnormal tissue structure. This prospective study evaluated women who developed AWS following breast cancer surgery. Using an 18 MHz ultrasound transducer, images were taken of the AWS cord and compared to mirror images on the contralateral side. A blinded radiologist assessed the ultrasound characteristics of and structural changes in the skin and subcutaneous tissue and formulated an opinion as to the side in which AWS was located. Seventeen subjects participated in the study. No structure or abnormality consistent with AWS could be identified by ultrasound. There were no statistical differences between the ipsilateral and contralateral side in skin thickness; subcutaneous reflector thickness, number or disorganization; or subcutaneous tissue echodensity (p>0.05). The radiologist correctly identified the side with AWS in 12 of 17 subjects (=0.41). A distinct ultrasonographic structure or abnormality could not be identified in subjects with AWS using 18 MHz ultrasound. The inability to identify a specific structure excludes the possibility that AWS is associated with vein thrombosis or a fascial abnormality, and supports the theory that AWS may be pathology that is not visible with 18 MHz ultrasound, such as microlymphatic stasis or binding of fibrin or other proteins in the interstitial space.
Assuntos
Braço/diagnóstico por imagem , Axila/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Excisão de Linfonodo/efeitos adversos , Vasos Linfáticos/diagnóstico por imagem , Linfedema/diagnóstico por imagem , Adulto , Axila/cirurgia , Estudos de Coortes , Feminino , Humanos , Linfedema/etiologia , Mastectomia , Mastectomia Segmentar , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Biópsia de Linfonodo Sentinela/efeitos adversos , Pele/diagnóstico por imagem , Síndrome , UltrassonografiaRESUMO
The purpose of this study was to evaluate a new device specifically designed for patent ductus arteriosus (PDA) occlusion based on PDA anatomy. Percutaneous closure of aortopulmonary shunts was attempted in 10 dogs. Shunts were surgically created in the location and orientation of PDA. The occlusion prosthesis consisted of a cylindrical frame filled with polyester and a 32 degree angled retention disk. The delivery system of the device included a 6 Fr thin-walled Teflon introducing sheath, an antirotating delivery catheter, and cable. Complete occlusion of the shunt was obtained in nine animals. One animal died before device placement. Temporary hemolysis occurred in one dog after device placement. The disk of device was completely covered by smooth glistening neoendothelium at 1-3 months postmortem examination. None of the devices protruded into the lumen of the aorta. The device is an improvement over the standard Amplatzer duct occluder. The angled retention disk lies flatly against the aortic wall, avoiding turbulence or an aortic pressure gradient.
Assuntos
Procedimentos Cirúrgicos Cardiovasculares/instrumentação , Permeabilidade do Canal Arterial/cirurgia , Animais , Aorta/cirurgia , Aortografia , Cães , Permeabilidade do Canal Arterial/diagnóstico por imagem , Desenho de Equipamento , Hemodinâmica/fisiologia , Hemólise , Modelos Animais , Complicações Pós-Operatórias/etiologia , Implantação de Prótese , Artéria Pulmonar/cirurgia , Trombose/etiologiaRESUMO
The aim of this study was to examine the feasibility of a hybrid interventional MR system, which combines a closed bore magnet with a C-arm fluoroscopy unit for percutaneous drainage of abdominal fluid collections. During the past 2 years, we have performed four drainage procedures in four patients (mean age 47 years). Three patients had abscesses (psoas muscle, kidney, subphrenic location) and the fourth patient had a recurrent splenic cyst. All procedures were performed on an interventional MR system consisting of a 1.5-T ACS-NT scanner combined with a specially shielded C-arm. The drainages were guided by T1-weighted fast gradient-echo images, T2-weighted single-shot turbo spin-echo images or both. A standard 18 G (1.2 mm) nonferromagnetic stainless steel needle with a Teflon sheath was used for the punctures following which a 0.89 mm nitinol guidewire was inserted into the fluid collection. Thereafter, the patient was positioned in the immediate adjacent fluoroscopy unit and a drainage catheter was placed under fluoroscopic control. All drainage catheters were successfully placed into the fluid collections, as proven by fluid aspiration and resolution of the collection. The mean time needed for the entire drainage procedure (MR and fluoroscopy) was 110 min. No procedure-related complications occurred. It is feasible to perform drainage procedures on a closed-bore MR scanner. The multiplanar imaging capabilities of MR are particularly helpful for fluid collections in the subphrenic location.
Assuntos
Abscesso Abdominal/terapia , Cistos/terapia , Drenagem/métodos , Fluoroscopia , Imageamento por Ressonância Magnética , Esplenopatias/terapia , Adulto , Idoso , Drenagem/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia Intervencionista , Resultado do TratamentoAssuntos
Artéria Ilíaca , Veia Ilíaca , Transplante de Rim , Doenças Vasculares Periféricas/cirurgia , Idoso , Humanos , Artéria Ilíaca/patologia , Veia Ilíaca/diagnóstico por imagem , Veia Ilíaca/patologia , Angiografia por Ressonância Magnética , Masculino , Doenças Vasculares Periféricas/diagnóstico , Doenças Vasculares Periféricas/etiologia , Flebografia , Complicações Pós-Operatórias , StentsRESUMO
Postpneumonectomy syndrome, a late complication of pneumonectomy, is secondary to shift of the mediastinum and remaining lung toward the pneumonectomy side, leading to tracheobronchial compression between the vertebral body and the aorta or pulmonary artery. Obstructive airway symptoms are usually due to tracheobronchial tree compression, however, secondary airway malacia may develop. We report herein a case of postpneumonectomy syndrome with secondary bronchomalacia after left pneumonectomy in a patient with normal mediastinal vascular anatomy.
Assuntos
Obstrução das Vias Respiratórias/etiologia , Broncopatias/etiologia , Pneumonectomia , Complicações Pós-Operatórias/etiologia , Adulto , Obstrução das Vias Respiratórias/diagnóstico por imagem , Obstrução das Vias Respiratórias/cirurgia , Broncopatias/diagnóstico por imagem , Broncopatias/cirurgia , Feminino , Fibrose , Humanos , Doenças do Mediastino/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/cirurgia , Reoperação , Tomografia Computadorizada por Raios XRESUMO
Fenoldopam is an interesting orphan drug that is a variant of dopamine. It differs significantly from dopamine in that it is a specific agonist for the type I (DA-1) receptor. The DA-1 receptors are particularly prominent in the renal vasculature, renal tubules, mesenteric vasculature, and peripheral vessels. The DA-1 receptor stimulation vasodilates renal and peripheral vessels, causing a decrease in blood pressure and an increase in renal blood flow (RBF). Stimulation of the DA-1 receptors in the tubules causes an increase in sodium excretion, which gives rise to an increase in urine volume on the basis of a sodium natriuresis. Animal testing with fenoldopam has indicated that it is 6 times more potent than dopamine in its ability to decrease renal vascular resistance and increase RBF; this suggests that it could be a much more selective and potent renal protective agent against any toxin or stimulus that causes renal dysfunction by reducing RBF or increasing renal ischemia. The clinical activity of fenoldopam, which is administered intravenously, begins almost immediately and is clearly noticeable after 5 minutes. The drug has no rebound effect, and its use can be stopped at any time. The protocol for the use of fenoldopam as a renal protective agent (performed at the University of Minnesota) involves starting an intravenous fenoldopam infusion 2 hours before the procedure at a rate of 0.1 microg/kg/min and increasing the dose in increments of 0.1 microg/kg/min every 20 minutes, until a rate of 0.5 microg/kg/min is reached or the systolic blood pressure falls more than 40 mm Hg (or below 110 mm Hg). Any infusion level at or above 0.1 microg/kg/min is considered acceptable because the response in individual patients varies so widely. The fenoldopam infusion is maintained at the maximum rate throughout the procedure and for up to 4 hours after the end of the contrast administration. At the University of Minnesota, we have had anecdotal experience using the drug in 29 patients. The drug was used for patients who were thought to be at the highest risk for contrast-induced nephropathy, ie, patients who have both diabetes and pre-existing renal failure. In this small group of patients in whom hydration and other variables were not controlled, there was a startling lack of contrast-induced creatinine increase at any point during the 24 to 48 hours after the administration of contrast in all but 1 patient. Our experience suggests that fenoldopam may be of distinct benefit to high-risk patients who need intravascular contrast, especially those who may receive a large contrast dose, such as patients undergoing peripheral or coronary angiography and intervention and/or computed tomography. Although it is impossible on the basis of simple anecdotal case reports to determine whether or not the drug was the primary reason that such a marked protective effect was seen, the results are promising enough to indicate that a careful, prospective, randomized trial of fenoldopam versus hydration is warranted.
Assuntos
Meios de Contraste/efeitos adversos , Agonistas de Dopamina/uso terapêutico , Fenoldopam/uso terapêutico , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Animais , Pressão Sanguínea/efeitos dos fármacos , Meios de Contraste/normas , Agonistas de Dopamina/normas , Relação Dose-Resposta a Droga , Fenoldopam/normas , Humanos , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , United States Food and Drug Administration , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/uso terapêuticoAssuntos
Cateterismo Periférico , Ativadores de Plasminogênio/uso terapêutico , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/uso terapêutico , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Arteriopatias Oclusivas/tratamento farmacológico , Oclusão de Enxerto Vascular/tratamento farmacológico , Humanos , Infusões Intravenosas , Ativadores de Plasminogênio/administração & dosagem , Ativador de Plasminogênio Tecidual/administração & dosagem , Estados Unidos , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Trombose Venosa/tratamento farmacológicoRESUMO
RATIONALE AND OBJECTIVES: The purpose of this study was to examine the effects of placing a metal stent across a bronchial orifice. MATERIALS AND METHODS: Nine pigs were used as test subjects, because the right upper lobe bronchus comes directly off the trachea in these animals. One of three types of metal stents was placed into the trachea of each pig and covered the orifice of the right upper lobe bronchus. Follow-up studies were performed at 1 and 3 months to evaluate the right upper lobe for signs of bronchial obstruction, infection, and atelectasis. The animals were sacrificed at 3 months to study the histopathologic changes of the trachea and lungs. RESULTS: Two upper lobe bronchi remained patent; seven were obstructed by granulation tissue or plugs of mucus and inflammatory cells. Right upper lobe infiltration and atelectasis were seen in eight animals. Interestingly, radiographic opacities were also common in other lung segments. There was a tendency toward fewer and less extensive lung opacities at 3 months compared with that at 1 month. At histopathologic examination, areas of both acute and chronic pneumonia were found in the right upper lobe of all animals. The segment of trachea covered by the stent was lined with a thin layer of granulation tissue containing neutrophils, monocytes, and lymphocytes. The stent luminal surface was covered with columnar, cuboidal, and stratified squamous epithelium. Tracheal stenosis was seen in three animals because of excessive granulation tissue in two and a collapsed stent in one. CONCLUSION: Placement of metal stents in pig trachea covering the orifice of the right upper lobe bronchus resulted in retention of secretions and secondary infection in the right upper lobe and other distant lung segments.
Assuntos
Brônquios/patologia , Modelos Animais de Doenças , Stents , Traqueia/patologia , Animais , Broncografia , Suínos , Traqueia/diagnóstico por imagemRESUMO
PURPOSE: To compare nonferromagnetic iliac artery prostheses in their suitability for patency monitoring with magnetic resonance angiography (MRA) using conventional angiography as a reference. METHODS: In experiment 1, three Memotherm stents were inserted into the iliac arteries of each of six sheep: two "tandem" stents on one side and a single stent on the other side. In experiment 2, four prostheses (normal and low-porosity Corvita stent-grafts, Memotherm, ZA-stent) were inserted in each of 11 sheep. Patency was monitored before and 1, 3, and 6 months after insertion with 3D phase-contrast and two 2D time-of-flight sequences (TOF-1: TR/TE = 18/6.9, TOF-2: 13/2.5) with and without contrast at 1.5 T. On 206 coronal MIP images (72 pre-, 134 post-stenting), three readers analyzed 824 iliac segments (206 x 4) for patency and artifacts. RESULTS: There was no difference in the number of artifacts between tandem and single iliac Memotherm stents. The ZA-stent induced significantly fewer artifacts than the other prostheses (p < 0.00001). With MRA, patency of the ZA-stent was correctly diagnosed in 88% of cases, which was almost comparable to nonstented iliac segments (95%), patency of the Memotherm stent in 59%, and of the Corvita stent-grafts in 57% and 55%. The TOF-2 sequence with contrast yielded the best images. CONCLUSION: MRA compatibility of nonferromagnetic prostheses depends strongly on the design of the device. MRA may be used to monitor the patency of iliac ZA-stents, whereas iliac Memotherm stents and Corvita stent-grafts appear to be less suited for follow-up with MRA.
Assuntos
Artéria Ilíaca/cirurgia , Angiografia por Ressonância Magnética , Stents , Grau de Desobstrução Vascular , Animais , Artefatos , Modelos Animais de Doenças , Artéria Ilíaca/diagnóstico por imagem , Masculino , Radiografia , Ovinos , Estatísticas não Paramétricas , Grau de Desobstrução Vascular/fisiologiaRESUMO
RATIONALE AND OBJECTIVES: To evaluate the imaging capabilities of ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in monitoring interstitial cryotherapy and to compare them with visual control. METHODS: An experimental MR-compatible, vacuum-insulated and liquid nitrogen-cooled cryoprobe was inserted under in vitro conditions into a porcine liver, which was kept at a temperature of 37 +/- 1 degrees C, in a water bath with continuous stirring. The freezing procedure was controlled macroscopically, by US (Toshiba Sonolayer, 7.5-MHz linear array transducer), by CT (Siemens Somatom Plus, slice thickness 2-8 mm, 165-210 mA at 120 kV), and by MRI (Philips Gyroscan ACS-NT, FFE TR/TE/FA = 15/5.4/25 degrees, T1-SE 550/20, T2-TSE 1800/100) after the iceball reached its maximum size. RESULTS: The maximum iceball diameter around the probe tip was 12.0 mm by visual control, 12.4 mm by US, 12.7 mm by CT, and within 12.8 mm by spin echo sequences and 11 mm by gradient echo sequence. Due to the nearly signal-free appearance of the frozen tissue on MR images, the ice/tissue contrast on T1-weighted and gradient echo images was superior to T2-weighted images and CT images. Sonographically, the ice formation appeared as a hyperechoic sickle with nearly complete acoustic shadowing. CONCLUSION: Due to the better ice/tissue contrast, T1-weighted or gradient echo MR images were superior to CT and US in monitoring interstitial cryotherapy. Gradient echo sequences generally underestimated the ice diameter by 15%.
Assuntos
Criocirurgia/métodos , Animais , Estudos de Avaliação como Assunto , Gelo , Técnicas In Vitro , Fígado/diagnóstico por imagem , Fígado/cirurgia , Imageamento por Ressonância Magnética , Suínos , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
PURPOSE: To evaluate the efficacy and safety of a new hydrodynamic catheter for removal of chronic iliac vein thrombus. METHODS: Unilateral iliac vein thrombosis was induced in seven pigs by combining permanent coil and temporary balloon occlusion. Thrombectomy was performed with a new hydrodynamic catheter (10 F S.E.T.) 3 days after thrombus induction. After thrombectomy, the animals were killed and the iliac veins were examined histologically. RESULTS: Complete thrombectomy (100% thrombus removal) was achieved in three of seven animals, 75% removal in three of seven animals, and only 30% removal in one animal. The average thrombus removal was 75%. Successful re-establishment of flow was achieved in five of seven cases. Histologically, the thrombi were partially organized, meeting the histologic criteria for early chronic venous thrombosis. Minor venous wall damage caused by the thrombectomy procedure without acute hemodynamic consequences was observed in four of seven cases. CONCLUSION: The 10-F S.E.T. catheter was reasonably effective in removing chronic iliac vein thrombus with no hemodynamically significant complications.
Assuntos
Veia Ilíaca/patologia , Trombectomia/instrumentação , Trombose/cirurgia , Animais , Plaquetas/patologia , Cateterismo Periférico/instrumentação , Doença Crônica , Desenho de Equipamento , Eritrócitos/patologia , Estudos de Avaliação como Assunto , Feminino , Fibrina/análise , Fluxo Sanguíneo Regional/fisiologia , Reologia , Segurança , Propriedades de Superfície , Suínos , Trombose/patologia , Resultado do Tratamento , Grau de Desobstrução Vascular/fisiologiaRESUMO
PURPOSE: To evaluate the clinical utility and morphologic accuracy of gadolinium-enhanced excretory magnetic resonance (MR) urography after low-dose diuretic injection and to correlate the results with those of conventional urography. MATERIALS AND METHODS: In 71 patients with urologic symptoms, excretory MR urography was performed after intravenous injection of 5-10 mg furosemide and, 30-60 seconds later, 0.1 mmol of gadopentetate dimeglumine per kilogram of body weight. The MR urograms were interpreted by three radiologists, who were blinded to the clinical outcome, and subsequently compared with conventional urograms. RESULTS: Injection of furosemide before contrast material led to rapid, uniform gadolinium distribution inside a sufficiently distended collecting system such that there was no excessive concentration of gadolinium in the urine. In patients with normal or moderately reduced excretory function, this effect allowed complete visualization of the urinary tract within 5-20 minutes of contrast material injection while minimizing gadolinium-related endoluminal T2* effects. The clinical course helped verify almost all MR urographic results. The MR urographic technique was significantly superior to conventional urography in the assessment of the ureters and bladder (P < .0001). Delineation of small caliceal abnormalities is still problematic. The best depiction of the pelvicaliceal system was obtained with fat-suppressed MR imaging, although it was still slightly inferior to conventional urography (P < .05). CONCLUSION: Gadolinium-enhanced excretory MR urography performed after low-dose diuretic injection is a promising and accurate alternative to conventional excretory urography for imaging the morphology of the urinary tract.
Assuntos
Meios de Contraste , Diuréticos , Furosemida , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Sistema Urinário/patologia , Urografia/métodos , Adulto , Idoso , Diuréticos/administração & dosagem , Feminino , Furosemida/administração & dosagem , Humanos , Iohexol/análogos & derivados , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Sensibilidade e Especificidade , Urografia/estatística & dados numéricosRESUMO
PURPOSE: To evaluate technique and practicability of MR-guided percutaneous nephrostomy (MRPCN) in an animal model. METHODS: In three domestic pigs, a unilateral percutaneous nephrostomy tube was placed into the nondilated collecting system using exclusively MR-guidance with a standard 1.5 T scanner. The urinary tract was visualized by intravenous injection of Gd-DTPA and low-dose furosemide. The entire interventional procedure was controlled using a T1-weighted "dual stack" 2 D TFE sequence in two orthogonal planes. RESULTS: In all three animals, the puncture needle was safely directed into the nondilated target calyx. Even slight deviations of the needle from the optimal path were readily detected on both MR image planes which enabled immediate correction. This technique successfully achieved a "first attempt" puncture of the targeted calyx in each animal. Over a nitinol guidewire a 5 F catheter was placed into the renal pelvis. Its dysprosium labelled tip was accurately delineated on contrast-enhanced MR images. CONCLUSIONS: Percutaneous nephrostomy under MR guidance is a very feasible technique for puncturing the nondilated pelvicalyceal system. This procedure offers some advantages over the current standard modalities.
Assuntos
Imageamento por Ressonância Magnética/métodos , Nefrostomia Percutânea/métodos , Animais , Meios de Contraste , Gadolínio DTPA , Aumento da Imagem , Masculino , SuínosRESUMO
The objective of this study was to assess the percent stenosis of the culprit lesion responsible for subsequent myocardial infarction in the Program on the Surgical Control of the Hyperlipidemias (POSCH). It is unknown if the susceptible coronary artery culprit lesion responsible for an acute myocardial infarction is relatively large ( > or = 50% arteriographic stenosis) and hemodynamically significant ( > or = 70% stenosis), or small ( < 50%, stenosis) and asymptomatic. Certain necropsy and arteriography studies support the large progenitor lesion concept, and other arteriography studies support the small lesion hypothesis. We analyzed the coronary arteriogram immediately preceding a Q wave (transmural) myocardial infarction for the degree of stenosis of the suspected culprit lesion, which was selected by visual inspection of the coronary circulation supplying the electrocardiogram-defined area of myocardial infarction. There was no perceptible difference with respect to vessel segment distribution of culprit lesions or time to infarction between the 52 control-group patients and the 27 intervention-group patients. For the two groups combined (n=79), the predominantly involved segments were the middle right coronary artery and the proximal left anterior descending coronary artery. The time interval from the preceding coronary arteriogram closest to the index myocardial infarction ranged from 0 days to 10 years; however, 64.6% of the arteriograms were performed 2 years or less prior to the myocardial infarction. Only 5.1% of the patients in both groups combined had a culprit lesion stenosis < 50%, while 88.6% of the patients in both groups combined had a culprit lesion stenosis > or = 70%. The results strongly favor the large lesion hypothesis of causation for myocardial infarction. It is premature, however, to state that the relative size of the culprit lesion has been indisputably determined. The resolution of this problem has exceedingly important practical implications for the management of patients with known atherosclerotic coronary heart disease and for those asymptomatic individuals with silent atherosclerotic coronary heart disease.
Assuntos
Doença das Coronárias , Infarto do Miocárdio/etiologia , Adulto , Angiografia Coronária , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/patologia , Doença das Coronárias/fisiopatologia , Humanos , Pessoa de Meia-Idade , Fatores de RiscoAssuntos
Braço/irrigação sanguínea , Hipertensão Pulmonar/etiologia , Embolia Pulmonar/complicações , Trombose/complicações , Adulto , Doença Crônica , Humanos , Hipertensão Pulmonar/diagnóstico por imagem , Masculino , Embolia Pulmonar/diagnóstico por imagem , Radiografia , Terapia Trombolítica , Trombose/diagnóstico por imagem , Trombose/tratamento farmacológicoRESUMO
PURPOSE: To evaluate and compare the healing response related to two types of graft-covered Wallstents (WSs) and an uncovered WS in the canine iliac artery. MATERIALS AND METHODS: Eight bare mesh WSs, 10 polyethylene terephthalate interbraided WSs (PET-WSs), and six polytetrafluoroethylene covered WSs (ePTFE-WSs) were placed in the iliac arteries of 12 dogs. Arteriograms were obtained before and after implantation and at explantation. Devices were explanted at 1 month (n = 8), 3 months (n = 6), and 6 months (n = 10) and sent for histologic study. RESULTS: One ePTFE-covered stent-graft was found to be thrombosed at 3 months; the remaining 23 of 24 implants remained patent to the time of explantation. The WS and ePTFE-WS both generated a uniform myointimal cell response without inflammation. The PET-WS induced a fibrous luminal response with substantial foreign body-type inflammatory reaction around the PET fibers. Although neointima associated with the PET-WS appeared thicker than that associated with either the ePTFE-WS or the bare WS, none of the patent implants developed greater than 50% angiographic narrowing. CONCLUSION: The PET-WS induced chronic inflammation, a response not seen with either the WS or ePTFE-WS. This may explain the occurrence of pain and/or fever in human studies of arterial PET endoluminal stent-grafts. Patency for all three implants was excellent in this model.
Assuntos
Reação a Corpo Estranho/etiologia , Artéria Ilíaca , Politetrafluoretileno , Stents , Animais , Cães , Reação a Corpo Estranho/patologia , Artéria Ilíaca/patologia , Túnica Íntima/patologia , Grau de Desobstrução Vascular/fisiologiaRESUMO
RATIONALE AND OBJECTIVES: The authors evaluate the sensitivity and specificity of a bedside test (SimpliRED) in the diagnosis of deep vein thrombosis compared with contrast phlebography. METHODS: Two hundred fifty patients, referred for phlebography, underwent bedside testing for detection of deep vein thrombosis. Contrast phlebography was performed immediately afterward. SimpliRED provides a clearly visible agglutination of the patient's red blood cells in the presence of elevated levels of cross-linked fibrin derivative (D-dimer), which is specific for fibrin breakdown. RESULTS: In 82 (32.8%) patients, deep vein thrombosis was confirmed venographically. An abnormal D-Dimer test was found in 79 of the 82 patients with thrombosis (sensitivity: 96.3%). The three patients who were diagnosed falsely as normal on agglutinin testing, had venograms which showed only an isolated calf thrombosis in small muscle veins (< 2 cm in diameter) not requiring treatment. One hundred of 168 patients without venographic thrombosis were diagnosed correctly by SimpliRED (specificity: 59.5%). The positive predictive value was 53.7%; the negative predictive value was 96.8%. CONCLUSIONS: All thrombotic disorders in the leg that required further treatment were identified correctly. SimpliRED is a very sensitive test with moderate specificity in the diagnosis of deep vein thrombosis. Therefore, further invasive testing is needed only in those patients in whom the D-dimer test is abnormal. A false-positive result of the bedside test may be nonspecific or due to elevated levels of fibrin split products, which can occur whenever the coagulation system has been activated by any of several conditions.
Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Tromboflebite/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Reações Falso-Positivas , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Humanos , Masculino , Pessoa de Meia-Idade , Flebografia , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
The purpose of the study was to test a newly developed, MR-compatible, liquid nitrogen-cooled cryoprobe. The probe has an outer diameter of 3.5 mm and was specifically developed for percutaneous, MR-guided, interstitial cryotherapy. The probe was inserted percutaneously into the livers of 10 rabbits. The cryotherapy procedure was monitored with a surface coil in a 1.5 Tesla magnet using a gradient echo sequence. Follow-up examinations were performed 3 and 7 days after the freezing procedure using T1- and T2-weighted spin echo sequences. At 7 days the animals were sacrificed and the cryolesions were examined histologically. The cryoprobe enabled artifact-free MR imaging of the "iceball" formation during freezing of the rabbit liver. After 1 min of freezing, the iceball at the tip of the probe showed an average maximum diameter of 10.8 mm. No bleeding complications were observed during or after the freezing procedure. Histologic examination 7 days after cryotherapy confirmed that the liver lesions were the same size as had been predicted by the images of the acute iceball. This new, percutaneously inserted, MR-compatible, liquid-nitrogen cooled cryoprobe allows accurate, artifact-free MR imaging of interstitial cryotherapy.