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An acousto-optic (AO)-based electric field sensor is presented for time domain measurement under magnetic resonance imaging (MRI). A fully MR-compatible sensor is designed and fabricated using a phase-shifted fiber Bragg grating mechanically coupled to a piezoelectric transducer. Mechanical resonance of the piezoelectric transducer is matched to the operating frequencies of commonly used MRI systems to increase the sensitivity of the sensor. Sensitivity of the sensor is measured as 1.27 mV/V/m, with a minimum detectable electric field of 4.4 mV/m/â/Hz. Directivity of the sensor is measured with a 18 dB orthogonal component rejection. The dynamic range of the sensor is calculated as 117 dB/Hz, which allows the measurement of electric fields up to 3.2 kV/m. In MRI studies, the AO sensor was able detect local hot spots around a reference implant accurately with high signal-to-noise ratio. AO sensor exhibited similar or better performance when compared with commercially available MRI compatible electric field sensors. Furthermore, the small size of the sensor with the flexible fiber optic link could allow in situ measurements of electric fields during critical interventional procedures such as pacemaker lead or deep brain stimulator placement as an MRI dosimeter during diagnostic scans.
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Transcatheter cardiovascular interventions increasingly rely on advanced imaging. X-ray fluoroscopy provides excellent visualization of catheters and devices, but poor visualization of anatomy. In contrast, magnetic resonance imaging (MRI) provides excellent visualization of anatomy and can generate real-time imaging with frame rates similar to X-ray fluoroscopy. Realization of MRI as a primary imaging modality for cardiovascular interventions has been slow, largely because existing guidewires, catheters and other devices create imaging artifacts and can heat dangerously. Nonetheless, numerous clinical centers have started interventional cardiovascular magnetic resonance (iCMR) programs for invasive hemodynamic studies or electrophysiology procedures to leverage the clear advantages of MRI tissue characterization, to quantify cardiac chamber function and flow, and to avoid ionizing radiation exposure. Clinical implementation of more complex cardiovascular interventions has been challenging because catheters and other tools require re-engineering for safety and conspicuity in the iCMR environment. However, recent innovations in scanner and interventional device technology, in particular availability of high performance low-field MRI scanners could be the inflection point, enabling a new generation of iCMR procedures. In this review we review these technical considerations, summarize contemporary clinical iCMR experience, and consider potential future applications.
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Cateterismo Cardíaco , Imagem por Ressonância Magnética Intervencionista , Humanos , Valor Preditivo dos Testes , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância MagnéticaRESUMO
PURPOSE: The purpose of this study was to investigate the impact of using flattening filter-free (FFF) beams and the aperture shape controller (ASC) on the complexity of conventional large-field treatment plans. METHODS AND MATERIALS: A total of 24 head and neck (H&N) and 24 prostate with pelvic nodes treatment plans were used in this study. Each plan was reoptimized using the original clinical objectives with both flattened and FFF beams, as well as six different ASC settings. The dosimetric qualities of each plan cohort were evaluated using commonly used dose-volume histogram values, and plan complexities were assessed through metrics including monitor unit (MU)/Dose, change in gantry speed, multileaf collimator (MLC) speed, the edge area ratio metric (EM), and the equivalent square length. RESULTS: No significant differences in dosimetric qualities were found between plans with flattened and FFF beams. The ASC settings did not have significant effects on dosimetric qualities in the H&N plan cohort, but the "very high" ASC setting resulted in poorer dosimetric results for the prostate plans. Plans with FFF beams had significantly higher MU/Dose compared to plans with flattened beams. The use of flattening filter (FF) had significant effects on the change in gantry speed, with flattened beams producing plans that required higher change in gantry speed. However, the FF did not have significant effects on MLC speed, EM, or equivalent square length. In contrast, ASC settings had significant effects on these three metrics; increasing the ASC level resulted in plans with decreasing MLC speed, lower edge area ratio, and higher equivalent square length. CONCLUSION: This study demonstrated that using FFF beams with various ASC settings, except for the "very high" level, can produce plans with reduced complexities without compromising dosimetric qualities in conventional large-field treatment plans.
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Radiocirurgia , Radioterapia de Intensidade Modulada , Masculino , Humanos , Radioterapia de Intensidade Modulada/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radiometria/métodos , Dosagem Radioterapêutica , Radiocirurgia/métodosRESUMO
Background: Red cell distribution width (RDW) has been shown to have predictive properties in different diseases as well as solid cancers. Aim: We aimed to investigate the discriminative properties of RDW in benign and malignant breast lesions. Subjects and Methods: In a retrospective cohort study the files of patients who underwent surgery for fibroadenomas (Group A) and breast cancer with axillary lymph node metastasis (Group B) were reviewed. The pathology reports and laboratory parameters and demographics of the patients were recorded for comparison. The patients were later excluded if they had an hemoglobin level below 12 mg/dl and the outliers were removed for a comparison. Seventy-six patients in the fibroadenoma group and 62 patients in the breast malignancy group were compared for the RDW levels to predict the presence of malignancy. Receiver operating characteristic curves were plotted for RDW and a threshold for prediction of malignancy was calculated. Results: The difference in RDW levels between group A and group B was found to be significant, 13,10% (IQR 12.60 -13.70) versus 13,80% (IQR 13.10-14.40) respectively, P = 0,00. The area under the curve was 0.71 (95% confidence interval 0.62 to 0.79), P = 0,00. For the threshold of 13,75 the positive predictive value was 67.35 (95% CI 55.72 to 77.17) and negative predictive value was 67.42 (95% CI 60.76% to 73.44). Conclusion: The RDW levels, after adjusted for anemia, were found to have a positive prediction for malignancy in more than two thirds of the patients for the level of 13.75%.
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Anemia , Neoplasias da Mama , Índices de Eritrócitos , Feminino , Humanos , Curva ROC , Estudos RetrospectivosRESUMO
A novel, breast-specific stereotactic radiotherapy device has been developed for delivery of highly conformal, accelerated partial breast irradiation. This device employs a unique, vacuum-assisted, breast cup immobilization system that applies a gentle, negative pressure to the target breast with the patient in the prone position. A device-specific patient loader is utilized for simulation scanning and device docking. Prior to clinical activation, a prospective protocol enrolled 25 patients who had been or were to be treated with breast conservation surgery and adjuvant radiotherapy for localized breast cancer. The patients underwent breast cup placement and two separate CT simulation scans. Surgical clips within the breast were mapped and positions measured against the device's integrated stereotactic fiducial/coordinate system to confirm reproducible and durable immobilization during the simulation, treatment planning, and delivery process for the device. Of the enrolled 25 patients, 16 were deemed eligible for analysis. Seventy-three clips (median, 4; mean, 4.6; range, 1-8 per patient) were mapped in these selected patients on both the first and second CT scans. X, Y, and Z coordinates were determined for the center point of each clip. Length of vector change in position was determined for each clip between the two scans. The mean displacement of implanted clips was 1.90 mm (median, 1.47 mm; range, 0.44-6.52 mm) (95% CI, 1.6-2.20 mm). Additional analyses stratified clips by position within the breast and depth into the immobilization cup. Overall, this effort validated the clinically utilized 3-mm planning target volume margin for accurate, reliable, and precise employment of the device.
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Neoplasias da Mama , Radiocirurgia , Mama , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Feminino , Humanos , Imobilização , Estudos Prospectivos , Planejamento da Radioterapia Assistida por Computador , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: The aim of this study was to investigate the effects of the cardiology patients' illness perception on their medication adherence will guide in the development of training and consultancy strategies. MATERIAL AND METHOD: The study was conducted with 110 patients who were followed up in the cardiology clinics of a university hospital. The study included patients over the age of 18 years, who agreed to participate in the study and were diagnosed with a cardiovascular disease at least six months before. The data were collected using a patient information form questioning the subjects such as the patients' age, gender, marital status and economic condition, the Illness Perception Questionnaire and the Morisky Medication Adherence Scale. RESULTS: The results showed that 72.7% (n=80) of the group had forgotten to take their medicine, 38.2% (n=42) had a trouble remembering to take their medicine, 29.1% (n=32) stopped taking their medicine when they felt good and 32.7% (n=36) stopped taking their medicine because they sometimes felt bad after taking their medicine. It was determined that there was no statistically significant correlation between Morisky Medication Adherence Scale scores and Illness Perception Questionnaire subscale scores (P >0.05). It was determined that there was a statistically significant difference between the educational backgrounds, in terms of the personal control subscale mean scores (P=0.003; P<0.01). CONCLUSION: Patients try to explain their disease in the light of their personal experiences, knowledge, values, beliefs, and needs. Illness perception which is among the most important factors providing treatment adherence is an important factor affecting many areas from the person's psychological adaptation to the course of disease. Illness perception and treatment adherence are affected by educational level.
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Doenças Cardiovasculares/terapia , Conhecimentos, Atitudes e Prática em Saúde , Percepção , Cooperação e Adesão ao Tratamento/estatística & dados numéricos , Adolescente , Adulto , Idoso , Atitude Frente a Saúde , Doenças Cardiovasculares/psicologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Inquéritos e Questionários , Cooperação e Adesão ao Tratamento/psicologia , Adulto JovemRESUMO
BACKGROUND: Prevention of malpractice is crucial for health care professionals since it could lead to morbidity and mortality. Personality traits of students, being health care professional candidates affect their academic self-efficacies and malpractice tendencies. OBJECTIVE: To investigate the effect of personality traits and academic self-efficacies of midwifery and nursing students on their malpractice tendencies. MATERIALS AND METHODS: The study was conducted with a total of 437 midwifery and nursing students studying at two universities between May and September 2019. The form of sociodemographic characteristics, Eysenck Personality Inventory, Academic Self-efficacy Scale, and Malpractice Tendency Scale were used to collect the data. RESULTS: In the malpractice tendency scale, the students had the lowest score from patient monitoring and equipment safety subscale (x¯ = 40.59 ± 5.41) and the highest score from the communication subscale (x¯ = 22.78 ± 3.01). In the personality inventory, they were found to have the lowest score from the psychoticism subscale and the highest score from the extraversion subscale. Their academic self-efficacy mean score was 14.69 ± 3 0.49. Academic self-efficacy score was higher in the 1st year compared to the 4th year (P < 0.05). A negative correlation was found between neuroticism and extraversion subscales and academic self-efficacy (P < 0.01). A negative correlation was found between malpractice tendency and academic self-efficacy (P < 0.01). CONCLUSION: It was observed that neuroticism and extraversion personality traits in students were found to be associated with low academic self-efficacy and increasing malpractice tendencies. Investigation of academic self-efficacy and malpractice tendencies of the students in accordance with their personality traits would contribute to the improvement, arrangement, and updating of educational curricula.
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Imperícia , Autoeficácia , Humanos , Personalidade , Estudantes , UniversidadesRESUMO
BACKGROUND: Open appendectomy (OA) has been the gold standard for a long time. Laparoscopic appendectomy (LA) has gained wide acceptance and popularity, outdoing open approach. Yet, conversion may be required when laparoscopic approach fails. AIMS: To predict conversion from laparoscopic appendectomy to open appendectomy sing Oreo-ratio radiological appendices diameter. MATERIALS AND METHODS: This is a retrospective cohort study conducted on 320 (included) patients who underwent appendectomy between January 2018 and August 2018 in the General Surgery departmentof Haseki Training and Research Hospital, Istanbul, Turkey. Appendiceal diameter obtained during preoperative radiological screening was evaluated about its relationship to conversion from LA to OA. Age, sex, inflammatory serum parameters and pathology reports were also investigated. RESULTS: A total of 269 (84%) cases were started LA and 17 (6,3%) laparoscopic cases were converted to open. The appendix diameter, the grade of inflammation (perforated or gangrenous), age, and c-reactive protein (CRP) were found to have significant importance in conversion, P = 0.003, P = 0.000, P = 0.042, and P = 0.018, respectively. When a cutoff of 50 years was chosen for age, the odds ratio (OR) was 3. For the appendiceal diameter of 14 mm, the OR was 3.0286. CONCLUSION: Preoperative evaluation of appendix diameter is a quick and useful method for a surgeon to distinguish cases with risk of conversion in the emergency department. The other risk factors associated with conversion of LA to OA are grade of inflammation, age and CRP levels.
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Apendicectomia/métodos , Apendicite/cirurgia , Apêndice/diagnóstico por imagem , Laparoscopia/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Apendicectomia/efeitos adversos , Apendicite/diagnóstico por imagem , Apêndice/anatomia & histologia , Apêndice/patologia , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Feminino , Humanos , Inflamação/sangue , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Estudos Retrospectivos , Resultado do Tratamento , Turquia/epidemiologiaRESUMO
OBJECTIVE: To demonstrate whether there is an association between jugular venous reflux and nonpulsatile subjective tinnitus (NST) using real-time four-dimensional magnetic resonance imaging (MRI) angiography. MATERIALS AND METHODS: Patients with unilateral NST who underwent contrast-enhanced MRI with a special protocol were included in the study. Thick slab dynamic maximum intensity projection images were obtained including interleaved stochastic trajectories (TWIST)-MRI examination. All patients were requested to perform Valsalva maneuver during the sequence. Jugular venous reflux grading was performed as follows: absence of reflux or if reflux does not reach the base of the skull: grade 0; if reflux reaches the jugular bulb, but no intracranial contrast is observed: grade 1; and if reflux extends into the intracranial cortical veins and/or the cavernous sinus above the jugular bulb: Grade 2. RESULTS: A total number of 30 patients, 23 male and 7 female, were included in the study. Jugular venous reflux was not identified (Grade 0) in 20 patients. Grade 1 reflux was determined in 7 cases and Grade 2 reflux was observed in 3 cases. Notably, only patients with Grade 2 reflux described worsening of their tinnitus symptoms during the examination and their daily activities as well. CONCLUSIONS: NST might also be associated with hemodynamic problems of the venous system and the MRI protocol starting with TWIST accompanied with Valsalva maneuver is not well-known, yet seems to be a feasible and beneficial method to detect potential jugular venous reflux in NST patients.
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Encéfalo/irrigação sanguínea , Veias Jugulares/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Zumbido/etiologia , Insuficiência Venosa/fisiopatologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Veias Jugulares/patologia , Masculino , Pessoa de Meia-Idade , Zumbido/fisiopatologia , Manobra de Valsalva , Insuficiência Venosa/complicações , Adulto JovemRESUMO
BACKGROUND: The identification of children who will have persistent asthma has become a focus of recent research. The aim of this study was to assess whether impulse oscillometry (IOS) has a diagnostic value to predict modified API (asthma predictive index) in pre-schoolers with recurrent wheezing. METHODS: Pre-school children aged 3-6 years with recurrent wheezing were enrolled. The study population was divided into two groups based on mAPI criteria. Lung function was assessed by IOS. RESULTS: 115 children were assessed; 75 (65.2%) of them were male. The median age was 39 months (min: 36, max: 68 months). 64 (55.6%) of the children were mAPI positive. The R5-R20% levels of children with positive mAPI were significantly higher compared to negative mAPI. Also, R5-R20% levels of children with parental asthma and R20% pred and resonant frequency (Fres) levels of children with inhalant sensitization were higher than those without. No significant differences were found in IOS indices between groups based on the presence of atopic dermatitis, food sensitization, eosinophilia, inhaled corticosteroid usage or wheezing without colds. R5-R20% and total IgE values were found to be significantly related to positive mAPI (aOR: 1.40, p=0.022 and aOR: 1.02, p=0.001, respectively). In the ROC analysis, R5-R20% levels >14.4 had a sensitivity of 75% and specificity of 53% for predicting a positive mAPI (p=0.003). CONCLUSION: IOS may help clinicians to identify the pre-school wheezers with a high risk of asthma.
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Asma/diagnóstico , Pulmão/fisiologia , Oscilometria/métodos , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina E/sangue , Masculino , Valor Preditivo dos Testes , Prognóstico , Recidiva , Respiração , Testes de Função Respiratória , Sons Respiratórios , Risco , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Despite growing evidence suggesting potential association between innate and adaptive immunity in viral-induced acute asthma, there is paucity of data in this area. OBJECTIVE: This study aimed to investigate the association of innate and adaptive immunity with acute asthma attacks by analysing the role of IFN-γ-inducible protein 10 (IP-10), TLR2, cathelicidin, vitamin D and cytokines. MATERIAL AND METHODS: This prospective study included 33 patients with viral-induced acute asthma and 30 children with controlled asthma. Nasopharyngeal swab samples were collected for virus identification and asthma attack scores assessed in acute asthma group. Blood sampling for IP-10, TLR2, cathelicidin, vitamin D levels, and spirometric indices were employed. RESULTS: Serum IP-10 and cathelicidin levels of acute asthma group were significantly higher and vitamin D levels were lower than controlled asthma group (IP-10; p=0.006, cathelicidin; p=0.002, vitamin D; p<0.001). Serum IP-10 levels showed a significant negative correlation with age (p=0.009), TLR2 (p=0.05) and spirometric indices (p=0.002) in all asthmatics and a significant positive correlation with parameters of asthma attack severity (p=0.03) in acute asthma group. Higher cathelicidin values showed significant positive relation to IP-10 (beta coefficient: 33, p=0.02). Serum IP-10 levels higher than 38.9pg/ml (sensitivity: 85%, specificity: 47%, p=0.002) were predictive of virus-induced asthma. Serum IP-10 and vitamin D levels were found to be significantly related to viral-asthma attacks (IP-10; aOR: 8.93, p=0.03 and vitamin D; aOR: 0.82, p=0.001). CONCLUSIONS: Innate immunity biomarkers such as serum IP-10 and cathelicidin can be used to predict viral-induced acute asthma. These biomarkers may provide potential new treatment targets for acute asthma.
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Peptídeos Catiônicos Antimicrobianos/sangue , Asma/diagnóstico , Biomarcadores/sangue , Quimiocina CXCL10/sangue , Viroses/diagnóstico , Vitamina D/sangue , Imunidade Adaptativa , Adolescente , Asma/etiologia , Criança , Citocinas/metabolismo , Progressão da Doença , Feminino , Humanos , Imunidade Inata , Masculino , Prognóstico , Estudos Prospectivos , Receptor 2 Toll-Like/metabolismo , Viroses/complicações , CatelicidinasRESUMO
We report a case of rudimentary horn pregnancy at 12 weeks gestation with fetal demise misdiagnosed ultrasonographically as an intrauterine pregnancy in a private clinic. The patient was referred to a tertiary care hospital after failed attempts at terminating her pregnancy. A definitive diagnosis was made with ultrasonography and magnetic resonance imaging (MRI) before uterine rupture ensued. Excision of the rudimentary horn and the ipsilateral fallopian tube was carried out by laparotomy. Failure to terminate pregnancy after several attempts should alert the physician about the possibility of a uterine anomaly and a pelvic MRI scan may help in the diagnosis of a suspected rudimentary horn pregnancy.
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Aborto Induzido , Imageamento por Ressonância Magnética/métodos , Ductos Paramesonéfricos/diagnóstico por imagem , Anormalidades Urogenitais/diagnóstico por imagem , Útero/anormalidades , Adulto , Feminino , Humanos , Laparotomia , Ductos Paramesonéfricos/anormalidades , Ductos Paramesonéfricos/cirurgia , Gravidez , Gravidez Ectópica/diagnóstico , Resultado do Tratamento , Anormalidades Urogenitais/cirurgia , Útero/diagnóstico por imagem , Útero/cirurgiaRESUMO
PURPOSE: The objective of this study was to evaluate fetal and perinatal outcomes of pregnancies of adolescents and compare them with adult pregnancies. MATERIALS AND METHODS: This retrospective case-control study was carried out at Bakirkoy Maternity and Children's Diseases Education and Research Hospital in Istanbul, Turkey. It enrolled 2,491 pregnancies who delivered between 2005-2010, of which 998 were adolescent pregnancies and 1,493 were adults as controls. RESULTS: The mean age of the adolescent group was 17.10 years and in the control group the mean age was found to be 26.73 years. Intermarriage, vaginal delivery, preterm rupture of membranes, preterm birth, and preeclampsia were significantly higher in adolescent pregnancies than the control group. Gestational diabetes was more common with increasing age. There was no statistically meaningful difference between the groups in terms of intrauterine growth restriction (IUGR), low birth weight, anemia, 5-minute APGAR score, and intrauterine fetal demise. CONCLUSIONS: Young maternal age is a risk factor for preterm birth, preterm rupture of membranes, and preeclampsia. According to this study, adolescent pregnancies are more risky and more likely to have adverse fetal outcomes.
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Complicações na Gravidez/epidemiologia , Gravidez na Adolescência/estatística & dados numéricos , Adolescente , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Masculino , Idade Materna , Assistência Perinatal , Gravidez , Complicações na Gravidez/etiologia , Complicações na Gravidez/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Turquia/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Acute aortic regurgitation is life-threatening with few nonsurgical options for immediate stabilization. We propose Trans-Aortic Balloon to Ease Regurgitation Applying Counter-Pulsation (TABERNACL), a simple, on-table temporary valve using commercially available equipment to temporize acute severe aortic regurgitation. METHODS: We hypothesize that an appropriately sized commercial balloon dilatation catheter-straddling the aortic annulus and connected to a counterpulsation console-can serve as a temporizing valve to restore hemodynamic stability in acute aortic regurgitation. We performed benchtop testing of valvuloplasty, angioplasty, and sizing balloons as counterpulsation balloons. TABERNACL was assessed in vivo in a porcine model of acute aortic regurgitation (n=8). We also tested a static undersized, continuously inflated transvalvular balloon as a spacer intended physically to obstruct the regurgitant orifice. RESULTS: Benchtop testing identified that Tyshak II and PTS sizing (NuMed Braun) balloon catheters performed adequately as temporary valves (ie, complete inflation and deflation with each cycle) and resisted fatigue, in contrast to others. When TABERNACL was used in the acute severe regurgitation animals, there was immediate hemodynamic improvement, with a significant 35% increase in diastolic aortic pressure by 16 mmâ Hg ([95% CI, 7-25] P=0.0056), 34% reduction in left ventricular end-diastolic pressure by -7 mmâ Hg ([95% CI, -10 to -5] P=0.0006), improvement in the aortic diastolic index by 0.28 ([95% CI, 0.18-0.39] P=0.0009), and reversal of electrocardiographic myocardial ischemia. As an alternative, static balloon inflation across the aortic valve stabilized regurgitation hemodynamics at the expense of a new aortic gradient and caused excessive ectopy from balloon movement in the left ventricular outflow tract. CONCLUSIONS: TABERNACL improves hemodynamics and reduces coronary ischemia by electrocardiography in animals with acute severe aortic regurgitation. TABERNACL valves obstruct the diastolic regurgitant orifice without systolic obstruction. This may prove a lifesaving bridge to definitive valve replacement therapy.
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Insuficiência da Valva Aórtica , Valvuloplastia com Balão , Modelos Animais de Doenças , Hemodinâmica , Animais , Hemodinâmica/efeitos dos fármacos , Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/etiologia , Insuficiência da Valva Aórtica/diagnóstico por imagem , Sus scrofa , Valva Aórtica/fisiopatologia , Valva Aórtica/cirurgia , Valva Aórtica/diagnóstico por imagem , Desenho de Equipamento , Recuperação de Função Fisiológica , Doença Aguda , Cateteres Cardíacos , Fatores de Tempo , Índice de Gravidade de Doença , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
BACKGROUND: Deep intramural ventricular tachycardia substrate targets are difficult to access, map, and ablate from endocardial and epicardial surfaces, resulting in high recurrence rates. OBJECTIVES: In this study, the authors introduce a novel approach called ventricular intramyocardial navigation for tachycardia ablation guided by electrograms (VINTAGE) to access and ablate anatomically challenging ventricular tachycardia from within the myocardium. METHODS: Guidewire/microcatheter combinations were navigated deep throughout the extravascular myocardium, accessed directly from the right ventricle cavity, in Yorkshire swine (6 naive, 1 infarcted). Devices were steered to various intramyocardial targets including the left ventricle summit, guided by fluoroscopy, unipolar electrograms, and/or electroanatomic mapping. Radiofrequency ablations were performed to characterize ablation parameters and reproducibility. Intramyocardial saline irrigation began 1 minute before ablation and continued throughout. Lesions were analyzed on cardiac magnetic resonance and necropsy. RESULTS: VINTAGE was feasible in all animals within naive and infarcted myocardium. Forty-three lesions were created, using various guidewires and power settings. Forty-one (95%) lesions were detected on cardiac magnetic resonance and 38 (88%) on necropsy; all undetected lesions resulted from intentionally subtherapeutic ablation energy (10 W). Larger-diameter guidewires yielded larger size lesions. Lesion volumes on necropsy were significantly larger at 20 W than 10 W (178 mm3 [Q1-Q3: 104-382 mm3] vs 49 mm3 [Q1-Q3: 35-93 mm3]; P = 0.02). Higher power (30 W) did not create larger lesions. Median impedance dropped with preablation irrigation by 12 Ω (Q1-Q3: 8-17 Ω), followed by a further 15-Ω (Q1-Q3: 11-19 Ω) drop during ablation. Intramyocardial navigation, ablation, and irrigation were not associated with any complications. CONCLUSIONS: VINTAGE was safe and effective at creating intramural ablation lesions in targets traditionally considered inaccessible from the endocardium and epicardium, both naive and infarcted. Intramyocardial guidewire irrigation and ablation at 20 W creates reproducibly large intramural lesions.
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Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Taquicardia Ventricular , Animais , Taquicardia Ventricular/cirurgia , Taquicardia Ventricular/fisiopatologia , Ablação por Cateter/métodos , Ablação por Cateter/instrumentação , Suínos , Técnicas Eletrofisiológicas Cardíacas/métodos , Ventrículos do Coração/cirurgia , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/diagnóstico por imagemRESUMO
AIM: Our aim is to introduce the cavernous artery ondulation index (CA-OI) as a new parameter that could be accepted as an indirect indicator of vascular hemodynamics and also gives us information about the efficiency of erection. PATIENTS AND METHODS: A total of 27 patients with erectile dysfunction were evaluated with penile Doppler ultrasonography (PDUS). After injection of papaverine intracavernously, arterial diameter and peak-systolic and end-diastolic velocities were measured. For measuring at a standart time, five minutes after injection, bilateral cavernosal arteries were examined and gray scale and color Doppler US images through the long axis were recorded at the mentioned phases. Cavernosal artery ondulation index (CA-OI) showing the amount of ondulation was calculated for each subject using these images. RESULTS: In 9 of total 27 patients, erection could not pass the tumescence phase with 3 flaccid phases, while the remaining 18 had full erection. Mean CA-OI values were measured as 2.51±0.37 mm, 3.15±0.38 mm, and 2.68±0.09 mm in normal, arterial insufficiency and venous insufficiency groups, respectively. CONCLUSIONS: It is possible to differentiate the arterial insufficiency by using the cut-off value of CA-OI ≥ 2.5 values as a criteria.
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Impotência Vasculogênica/diagnóstico por imagem , Pênis/irrigação sanguínea , Pênis/diagnóstico por imagem , Ultrassonografia Doppler em Cores/métodos , Insuficiência Venosa/diagnóstico por imagem , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.
Assuntos
Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Doenças Vasculares , Humanos , Eletrocirurgia/efeitos adversos , Eletrocirurgia/métodos , Resultado do Tratamento , CateterismoRESUMO
BACKGROUND: Intramyocardial guidewire navigation is a novel technique that allows free transcatheter movement within ventricular muscle. Guidewire radial depth, between endocardial and epicardial surfaces, is ambiguous by x-ray and echocardiography. OBJECTIVES: The aim of this study was to develop a simple tool, EDEN (Electrocardiographic Radial Depth Navigation), to indicate radial depth during intramyocardial guidewire navigation. Combined with routine imaging, EDEN facilitates a new family of intramyocardial catheter procedures to slice, reshape, pace, and ablate the heart. METHODS: We mapped intramyocardial electrograms of left and right ventricular walls and septum during open- and closed-chest swine procedures (N = 53), including MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) ventriculoplasty. We identified radial depth-dependent features on unipolar electrograms. We developed a machine learning-based classifier to indicate categorical position, and modeled the findings in silico to test understanding of the physiology. RESULTS: EDEN signatures distinguished 5 depth zones throughout left and right ventricular free walls and interventricular septum. Relative ST-segment elevation magnitude best discriminated position and was maximum (40.1 ± 6.5 mV) in the midmyocardium. Subendocardial positions exhibited dominant Q waves with lower-amplitude ST segments (16.8 ± 5.8 mV), whereas subepicardial positions exhibited dominant R waves with lower-amplitude ST segments (15.7 ± 4.8 mV). EDEN was unaffected by pacing-induced left bundle branch block. ST-segment elevation declined over minutes and reappeared after submillimeter guidewire manipulation. Modeling recapitulated EDEN features. The machine learning-based classifier was 97% accurate. EDEN successfully guided MIRTH ventriculoplasty. CONCLUSIONS: EDEN provides a simple and reproducible real-time reflection of categorical guidewire-tip radial depth during intramyocardial guidewire navigation. Used in tandem with x-ray, EDEN enables novel, transcatheter, intramyocardial therapies such as MIRTH, SESAME (Septal Surfing Along Midline Endocardium), and cerclage ventriculoplasty.
Assuntos
Eletrocardiografia , Miocárdio , Animais , Suínos , Eletrocardiografia/métodos , Coração , Endocárdio , Ventrículos do Coração/diagnóstico por imagemRESUMO
MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.
RESUMO
PURPOSE: We aimed to put forward the contribution of virtual bronchoscopy in the determination and diagnosis of tracheobronchial system pathologies. We compared the data obtained from PET/CT and virtual bronchoscopy (VB) with the fiberoptic bronchoscopy (FOB) data of the cases with a diagnosis or pre-diagnosis of lung tumor. MATERIALS AND METHODS: A total of 261 (male=238, female=23) lung cancer cases with a mean age of 53±7.3 years (range =35-77 years), who had undergone FOB and had bronchoalveolar lavage and/or biopsy results, were included in this multicenter, prospective study conducted between 2006 and 2008. FOB data confirmed with cytohistopathology were considered as the gold standard. Five cases that had peripheral lesions, with negative cytopathological results were excluded from the study. Positron emission tomography images were fused with 16/slice multi-detector computed tomography system images (Discovery ST PET/16 slice CT fusion system HPOWER 60; General Electric Medical Systems, Milwaukee, WI, USA). Thereafter, all of the cases were evaluated with virtual bronchoscopy, using a special multidisplay workstation with multiplanar reformatting (MPR) and minimum intensity projection (MINIP) to see the fused images simultaneously. The data obtained with both virtual bronchoscopy (PET/CT VB) and FOB in different centers were recorded, and the evaluation and comparison of these data were done by an independent researcher. The sensitivity, specificity, and positive and negative predictive values of making an accurate diagnosis and defining concomitant pathologies by both methods, were calculated. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy values of VB and PET/CT-VB in determining the segment involved by malignancy were as follows, 91%, 83%, 94%, 77%, and 89%, and 95%, 97%, 99%, 87%, and 96%, respectively. CONCLUSIONS: The sensitivity of PET/CT-VB in determining the involved tracheobronchial segment(s) in malignancy and concomitant pathologies in cases with lung tumor was remarkably higher than that with CT-VB. Therefore, PET/CT-VB is recommended to be included in routine lung cancer examinations since it provides similar outcomes to that of FOB+cytohistopathological examination.