Tricuspid valve flow measurement using a deep learning framework for automated valve-tracking 2D phase contrast.

PURPOSE: Tricuspid valve flow velocities are challenging to measure with cardiovascular MR, as the rapidly moving valvular plane prohibits direct flow evaluation, but they are vitally important to diastolic function evaluation. We developed an automated valve-tracking 2D method for measuring flow through the dynamic tricuspid valve. METHODS: Nine healthy subjects and 2 patients were imaged. The approach uses a previously trained deep learning network, TVnet, to automatically track the tricuspid valve plane from long-axis cine images. Subsequently, the tracking information is used to acquire 2D phase contrast (PC) with a dynamic (moving) acquisition plane that tracks the valve. Direct diastolic net flows evaluated from the dynamic PC sequence were compared with flows from 2D-PC scans acquired in a static slice localized at the end-systolic valve position, and also ventricular stroke volumes (SVs) using both planimetry and 2D PC of the great vessels. RESULTS: The mean tricuspid valve systolic excursion was 17.8 ± 2.5 mm. The 2D valve-tracking PC net diastolic flow showed excellent correlation with SV by right-ventricle planimetry (bias ± 1.96 SD = -0.2 ± 10.4 mL, intraclass correlation coefficient [ICC] = 0.92) and aortic PC (-1.0 ± 13.8 mL, ICC = 0.87). In comparison, static tricuspid valve 2D PC also showed a strong correlation but had greater bias (p = 0.01) versus the right-ventricle SV (10.6 ± 16.1 mL, ICC = 0.61). In most (8 of 9) healthy subjects, trace regurgitation was measured at begin-systole. In one patient, valve-tracking PC displayed a high-velocity jet (380 cm/s) with maximal velocity agreeing with echocardiography. CONCLUSION: Automated valve-tracking 2D PC is a feasible route toward evaluation of tricuspid regurgitant velocities, potentially solving a major clinical challenge.

Quality control-driven deep ensemble for accountable automated segmentation of cardiac magnetic resonance LGE and VNE images.

Background: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging is the gold standard for non-invasive myocardial tissue characterisation. However, accurate segmentation of the left ventricular (LV) myocardium remains a challenge due to limited training data and lack of quality control. This study addresses these issues by leveraging generative adversarial networks (GAN)-generated virtual native enhancement (VNE) images to expand the training set and incorporating an automated quality control-driven (QCD) framework to improve segmentation reliability. Methods: A dataset comprising 4,716 LGE images (from 1,363 patients with hypertrophic cardiomyopathy and myocardial infarction) was used for development. To generate additional clinically validated data, LGE data were augmented with a GAN-based generator to produce VNE images. LV was contoured on these images manually by clinical observers. To create diverse candidate segmentations, the QCD framework involved multiple U-Nets, which were combined using statistical rank filters. The framework predicted the Dice Similarity Coefficient (DSC) for each candidate segmentation, with the highest predicted DSC indicating the most accurate and reliable result. The performance of the QCD ensemble framework was evaluated on both LGE and VNE test datasets (309 LGE/VNE images from 103 patients), assessing segmentation accuracy (DSC) and quality prediction (mean absolute error (MAE) and binary classification accuracy). Results: The QCD framework effectively and rapidly segmented the LV myocardium (<1 s per image) on both LGE and VNE images, demonstrating robust performance on both test datasets with similar mean DSC (LGE: 0.845±0.075; VNE: 0.845±0.071; p=ns). Incorporating GAN-generated VNE data into the training process consistently led to enhanced performance for both individual models and the overall framework. The quality control mechanism yielded a high performance (MAE=0.043, accuracy=0.951) emphasising the accuracy of the quality control-driven strategy in predicting segmentation quality in clinical settings. Overall, no statistical difference (p=ns) was found when comparing the LGE and VNE test sets across all experiments. Conclusions: The QCD ensemble framework, leveraging GAN-generated VNE data and an automated quality control mechanism, significantly improved the accuracy and reliability of LGE segmentation, paving the way for enhanced and accountable diagnostic imaging in routine clinical use.

Artificial Intelligence for Contrast-Free MRI: Scar Assessment in Myocardial Infarction Using Deep Learning-Based Virtual Native Enhancement.

BACKGROUND: Myocardial scars are assessed noninvasively using cardiovascular magnetic resonance late gadolinium enhancement (LGE) as an imaging gold standard. A contrast-free approach would provide many advantages, including a faster and cheaper scan without contrast-associated problems. METHODS: Virtual native enhancement (VNE) is a novel technology that can produce virtual LGE-like images without the need for contrast. VNE combines cine imaging and native T1 maps to produce LGE-like images using artificial intelligence. VNE was developed for patients with previous myocardial infarction from 4271 data sets (912 patients); each data set comprises slice position-matched cine, T1 maps, and LGE images. After quality control, 3002 data sets (775 patients) were used for development and 291 data sets (68 patients) for testing. The VNE generator was trained using generative adversarial networks, using 2 adversarial discriminators to improve the image quality. The left ventricle was contoured semiautomatically. Myocardial scar volume was quantified using the full width at half maximum method. Scar transmurality was measured using the centerline chord method and visualized on bull's-eye plots. Lesion quantification by VNE and LGE was compared using linear regression, Pearson correlation (R), and intraclass correlation coefficients. Proof-of-principle histopathologic comparison of VNE in a porcine model of myocardial infarction also was performed. RESULTS: VNE provided significantly better image quality than LGE on blinded analysis by 5 independent operators on 291 data sets (all P<0.001). VNE correlated strongly with LGE in quantifying scar size (R, 0.89; intraclass correlation coefficient, 0.94) and transmurality (R, 0.84; intraclass correlation coefficient, 0.90) in 66 patients (277 test data sets). Two cardiovascular magnetic resonance experts reviewed all test image slices and reported an overall accuracy of 84% for VNE in detecting scars when compared with LGE, with specificity of 100% and sensitivity of 77%. VNE also showed excellent visuospatial agreement with histopathology in 2 cases of a porcine model of myocardial infarction. CONCLUSIONS: VNE demonstrated high agreement with LGE cardiovascular magnetic resonance for myocardial scar assessment in patients with previous myocardial infarction in visuospatial distribution and lesion quantification with superior image quality. VNE is a potentially transformative artificial intelligence-based technology with promise in reducing scan times and costs, increasing clinical throughput, and improving the accessibility of cardiovascular magnetic resonance in the near future.

Afrontando la tercera ola de COVID-19 en el departamento de emergencia del Hospital Nacional Edgardo Rebagliati Martins, Lima, Perú, 2021

Perú ha sido uno de los países más afectados por la pandemia de COVID-19. Luego de haber sufrido dos olas epidémicas devastadoras, el departamento de emergencia del Hospital Nacional Edgardo Rebagliati Martins mantuvo como reto la preparación, de forma constante y dinámica, para afrontar una tercera ola que ya azotó a muchos países del mundo. Para esto, el departamento se preparó en todos los ámbitos para contribuir a la reducción del impacto de la enfermedad, garantizando no solo la calidad en la atención, sino también la seguridad del personal de salud, modulando la carga laboral y mental generada por la sobredemanda de la pandemia. De esta manera, el departamento estuvo mejor preparado cuando ocurrió la tercera ola. En conclusión, la preparación constante y dinámica es fundamental para afrontar el aumento de casos; así como también, garantizar la seguridad y bienestar del personal de salud.

Peru has been one of the countries most affected by the COVID-19 pandemic. After having suffered two devastating epidemic waves, the emergency department of the Edgardo Rebagliati Martins National Hospital maintained the challenge of constantly and dynamically preparing to face a third wave that has already hit many countries around the world. For this, the department prepared itself in all areas, to contribute to reducing the impact of the disease, guaranteeing not only the quality of care, but also the safety of health personnel, modulating the work and mental load generated by the pandemic over-demand. In this way, the department was better prepared when the third wave occurred. In conclusion, constant and dynamic preparation is essential to face the increase in cases; as well as to guarantee the safety and well- being of health personnel.

MOCOnet: Robust Motion Correction of Cardiovascular Magnetic Resonance T1 Mapping Using Convolutional Neural Networks.

Background: Quantitative cardiovascular magnetic resonance (CMR) T1 mapping has shown promise for advanced tissue characterisation in routine clinical practise. However, T1 mapping is prone to motion artefacts, which affects its robustness and clinical interpretation. Current methods for motion correction on T1 mapping are model-driven with no guarantee on generalisability, limiting its widespread use. In contrast, emerging data-driven deep learning approaches have shown good performance in general image registration tasks. We propose MOCOnet, a convolutional neural network solution, for generalisable motion artefact correction in T1 maps. Methods: The network architecture employs U-Net for producing distance vector fields and utilises warping layers to apply deformation to the feature maps in a coarse-to-fine manner. Using the UK Biobank imaging dataset scanned at 1.5T, MOCOnet was trained on 1,536 mid-ventricular T1 maps (acquired using the ShMOLLI method) with motion artefacts, generated by a customised deformation procedure, and tested on a different set of 200 samples with a diverse range of motion. MOCOnet was compared to a well-validated baseline multi-modal image registration method. Motion reduction was visually assessed by 3 human experts, with motion scores ranging from 0% (strictly no motion) to 100% (very severe motion). Results: MOCOnet achieved fast image registration (<1 second per T1 map) and successfully suppressed a wide range of motion artefacts. MOCOnet significantly reduced motion scores from 37.1±21.5 to 13.3±10.5 (p < 0.001), whereas the baseline method reduced it to 15.8±15.6 (p < 0.001). MOCOnet was significantly better than the baseline method in suppressing motion artefacts and more consistently (p = 0.007). Conclusion: MOCOnet demonstrated significantly better motion correction performance compared to a traditional image registration approach. Salvaging data affected by motion with robustness and in a time-efficient manner may enable better image quality and reliable images for immediate clinical interpretation.

MVnet: automated time-resolved tracking of the mitral valve plane in CMR long-axis cine images with residual neural networks: a multi-center, multi-vendor study.

BACKGROUND: Mitral annular plane systolic excursion (MAPSE) and left ventricular (LV) early diastolic velocity (e') are key metrics of systolic and diastolic function, but not often measured by cardiovascular magnetic resonance (CMR). Its derivation is possible with manual, precise annotation of the mitral valve (MV) insertion points along the cardiac cycle in both two and four-chamber long-axis cines, but this process is highly time-consuming, laborious, and prone to errors. A fully automated, consistent, fast, and accurate method for MV plane tracking is lacking. In this study, we propose MVnet, a deep learning approach for MV point localization and tracking capable of deriving such clinical metrics comparable to human expert-level performance, and validated it in a multi-vendor, multi-center clinical population. METHODS: The proposed pipeline first performs a coarse MV point annotation in a given cine accurately enough to apply an automated linear transformation task, which standardizes the size, cropping, resolution, and heart orientation, and second, tracks the MV points with high accuracy. The model was trained and evaluated on 38,854 cine images from 703 patients with diverse cardiovascular conditions, scanned on equipment from 3 main vendors, 16 centers, and 7 countries, and manually annotated by 10 observers. Agreement was assessed by the intra-class correlation coefficient (ICC) for both clinical metrics and by the distance error in the MV plane displacement. For inter-observer variability analysis, an additional pair of observers performed manual annotations in a randomly chosen set of 50 patients. RESULTS: MVnet achieved a fast segmentation (<1 s/cine) with excellent ICCs of 0.94 (MAPSE) and 0.93 (LV e') and a MV plane tracking error of -0.10 ± 0.97 mm. In a similar manner, the inter-observer variability analysis yielded ICCs of 0.95 and 0.89 and a tracking error of -0.15 ± 1.18 mm, respectively. CONCLUSION: A dual-stage deep learning approach for automated annotation of MV points for systolic and diastolic evaluation in CMR long-axis cine images was developed. The method is able to carefully track these points with high accuracy and in a timely manner. This will improve the feasibility of CMR methods which rely on valve tracking and increase their utility in a clinical setting.

Automated left atrial time-resolved segmentation in MRI long-axis cine images using active contours.

BACKGROUND: Segmentation of the left atrium (LA) is required to evaluate atrial size and function, which are important imaging biomarkers for a wide range of cardiovascular conditions, such as atrial fibrillation, stroke, and diastolic dysfunction. LA segmentations are currently being performed manually, which is time-consuming and observer-dependent. METHODS: This study presents an automated image processing algorithm for time-resolved LA segmentation in cardiac magnetic resonance imaging (MRI) long-axis cine images of the 2-chamber (2ch) and 4-chamber (4ch) views using active contours. The proposed algorithm combines mitral valve tracking, automated threshold calculation, edge detection on a radially resampled image, edge tracking based on Dijkstra's algorithm, and post-processing involving smoothing and interpolation. The algorithm was evaluated in 37 patients diagnosed mainly with paroxysmal atrial fibrillation. Segmentation accuracy was assessed using the Dice similarity coefficient (DSC) and Hausdorff distance (HD), with manual segmentations in all time frames as the reference standard. For inter-observer variability analysis, a second observer performed manual segmentations at end-diastole and end-systole on all subjects. RESULTS: The proposed automated method achieved high performance in segmenting the LA in long-axis cine sequences, with a DSC of 0.96 for 2ch and 0.95 for 4ch, and an HD of 5.5 mm for 2ch and 6.4 mm for 4ch. The manual inter-observer variability analysis had an average DSC of 0.95 and an average HD of 4.9 mm. CONCLUSION: The proposed automated method achieved performance on par with human experts analyzing MRI images for evaluation of atrial size and function. Video Abstract.

Deep neural network ensemble for on-the-fly quality control-driven segmentation of cardiac MRI T1 mapping.

Recent developments in artificial intelligence have generated increasing interest to deploy automated image analysis for diagnostic imaging and large-scale clinical applications. However, inaccuracy from automated methods could lead to incorrect conclusions, diagnoses or even harm to patients. Manual inspection for potential inaccuracies is labor-intensive and time-consuming, hampering progress towards fast and accurate clinical reporting in high volumes. To promote reliable fully-automated image analysis, we propose a quality control-driven (QCD) segmentation framework. It is an ensemble of neural networks that integrate image analysis and quality control. The novelty of this framework is the selection of the most optimal segmentation based on predicted segmentation accuracy, on-the-fly. Additionally, this framework visualizes segmentation agreement to provide traceability of the quality control process. In this work, we demonstrated the utility of the framework in cardiovascular magnetic resonance T1-mapping - a quantitative technique for myocardial tissue characterization. The framework achieved near-perfect agreement with expert image analysts in estimating myocardial T1 value (r=0.987,p<.0005; mean absolute error (MAE)=11.3ms), with accurate segmentation quality prediction (Dice coefficient prediction MAE=0.0339) and classification (accuracy=0.99), and a fast average processing time of 0.39 second/image. In summary, the QCD framework can generate high-throughput automated image analysis with speed and accuracy that is highly desirable for large-scale clinical applications.

Características y evolución de pacientes con litiasis urinaria en emergencia de un hospital terciario / Characteristics And Evolution Of Patients With Urinary Lithiasis In A Tertiary Hospital Emergency

Antecedentes: La sintomatología y complicaciones de litiasis urinaria son una causa frecuente de atención en emergencia. Objetivos: Determinar características y evolución de pacientes con litiasis urinaria atendidos en el servicio de emergencia de un hospital terciario de la seguridad social. Métodos: Estudio observacional realizado en el hospital Rebagliati Lima-Perú, durante el primer trimestre 2019. Se evaluó variables sociodemográficas, de tiempo e indicadores de emergencia del sistema estadístico institucional, realizando estadística descriptiva con IBM SPSS 25.0. Resultados: Se registraron 583 atenciones por litiasis urinaria (194 por mes), correspondiendo al 14% de la patología genito-urinaria vista en el servicio evaluado. 55% de sexo masculino, edad promedio 48 años (rango 14 a 92). Atendidos principalmente por tópico de cirugía y de prioridad 3, causas más frecuentes dolor, infección y hematuria. Tiempo de primera atención 4,8 horas, saliendo de alta el 70%. Se admitió a salas de observación 10,5% con estancia promedio de 77 horas (3,2 días), siendo hospitalizada 51%, de alta 31%, operada 3% y falleció 2%. Conclusión: La litiasis urinaria se presenta en 1 de cada 7 atenciones de patología genitourinaria del servicio de emergencia evaluado, predominando en varones, de edad media, el 10% es admitido a sala de observación, con corta estancia y baja mortalidad.

Background: The symptoms and complications of urinary lithiasis are a frequent cause of emergency care. Objectives: To determine characteristics and evolution of patients with urinary lithiasis attended in the emergency room of a tertiary social security hospital. Methods: Observational study carried out at the Rebagliati hospital Lima-Peru, during the first quarter of 2019. Sociodemographic variables, time and emergency indicators of the institutional statistical system were evaluated, performing descriptive statistics with IBM SPSS 25.0. Results: 583 attentions for urinary lithiasis (194 per month) were registered, corresponding to 14% of the genito-urinary pathology seen in the evaluated service. 55% male, average age 48 years (range 14 to 92). Mainly attended by surgical topic and priority 3, most frequent causes pain, infection and hematuria. Time of first attention 4.8 hours, leaving 70% of discharge. Observation rooms were admitted to 10.5% with an average stay of 77 hours (3.2 days), with 51% hospitalized, discharge 31%, operated 3% and 2% died. Conclusion: Urinary lithiasis occurs in 1 out of 7 genitourinary pathologies of the emergency room evaluated, predominantly in middle-aged men, 10% are admitted to the observation room, with a short stay and low mortality.

Valvular imaging in the era of feature-tracking: A slice-following cardiac MR sequence to measure mitral flow.

BACKGROUND: In mitral valve dysfunction, noninvasive measurement of transmitral blood flow is an important clinical examination. Flow imaging of the mitral valve, however, is challenging, since it moves in and out of the image plane during the cardiac cycle. PURPOSE: To more accurately measure mitral flow, a slice-following MRI phase contrast sequence is proposed. This study aimed to implement such a sequence, validate its slice-following functionality in a phantom and healthy subjects, and test its feasibility in patients with mitral valve dysfunction. STUDY TYPE: Prospective. PHANTOM AND SUBJECTS: The slice-following functionality was validated in a cone-shaped phantom by measuring the depicted slice radius. Sixteen healthy subjects and 10 mitral valve dysfunction patients were enrolled at two sites. FIELD STRENGTH/SEQUENCE: 1.5T and 3T gradient echo cine phase contrast. ASSESSMENT: A single breath-hold retrospectively gated sequence using offline feature-tracking of the mitral valve was developed. Valve displacements were measured and imported to the scanner, allowing the slice position to change dynamically based on the cardiac phase. Mitral valve imaging was performed with slice-following and static imaging planes. Validation was performed by comparing mitral stroke volume with planimetric and aortic stroke volume. STATISTICAL TESTS: Measurements were compared using linear regression, Pearson's R, parametric paired t-tests, Bland-Altman analysis, and intraclass correlation coefficient (ICC). RESULTS: Phantom experiments confirmed accurate slice displacements. Slice-following was feasible in all subjects, yielding physiologically accurate mitral flow patterns. In healthy subjects, mitral and aortic stroke volumes agreed, with ICC = 0.72 and 0.90 for static and slice-following planes; with bias ±1 SDs 23.2 ± 13.2 mls and 8.4 ± 10.8 mls, respectively. Agreement with planimetry was stronger, with ICC = 0.84 and 0.96; bias ±1 SDs 13.7 ± 13.7 mls and -2.0 ± 8.8 mls for static and slice-following planes, respectively. DATA CONCLUSION: Slice-following outperformed the conventional sequence and improved the accuracy of transmitral flow, which is important for assessment of diastolic function and mitral regurgitation. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1412-1421.

Assessment of diastolic function and atrial remodeling by MRI - validation and correlation with echocardiography and filling pressure.

Atrial fibrosis can be estimated noninvasively by magnetic resonance imaging (MRI) using late gadolinium enhancement (LGE), but diastolic dysfunction is clinically assessed by transthoracic echocardiography (TTE), and rarely by MRI. This study aimed to evaluate well-established diastolic parameters using MRI, and validate them with TTE and left ventricular (LV) filling pressures, and to study the relationship between left atrial (LA) remodeling and parameters of diastolic function. The study retrospectively included 105 patients (53 ± 16 years, 39 females) who underwent 3D LGE MRI between 2012 and 2016. Medical charts were reviewed for the echocardiographic diastolic parameters E, A, and e' by TTE, and pressure catheterizations. E and A were measured from in-plane phase-contrast cardiac MRI images, and e' by feature-tracking, and validated with TTE. Interobserver and intraobserver variability was examined. Furthermore, LA volumes, function, and atrial LGE was correlated with diastolic parameters. Evaluation of e' in MRI had strong agreement with TTE (r = 0.75, P < 0.0001), and low interobserver and intraobserver variability. E and A by TTE showed strong agreement to MRI (r = 0.77, P = 0.001; r = 0.73, P = 0.003, for E and A, respectively). Agreement between E/e' by TTE and MRI was strong (r = 0.85, P = 0.0004), and E/e' by TTE correlated moderately to invasive pressures (r = 0.59, P = 0.03). There was a strong relationship between LA LGE and pulmonary capillary wedge pressure (r = 0.81, P = 0.01). In conclusion, diastolic parameters can be measured with good reproducibility by cardiovascular MRI. LA LGE exhibited a strong relationship with pulmonary capillary wedge pressure, an indicator of diastolic function.

Pulmonary lymphangioleiomyomatosis: literature update.

Pulmonary lymphangioleiomyomatosis is an uncommon disease of unknown etiology characterized by the proliferation of abnormal smooth muscle cells in the lungs, leading to parenchymal destruction and progressive respiratory failure. The natural history of this disease remains poorly understood, primarily seen in women of childbearing age. The diagnosis can be difficult because symptoms are nonspecific and very similar to other respiratory diseases like asthma, emphysema and bronchitis. Lymphangioleiomyomatosis may not be diagnosed until a pneumothorax, chylothorax, interstitial lung disease or angiomyolipomas are discovered. The recent advances in genetic and molecular research provide new hope to discover the intricate mechanism of disease and evaluate new therapies. Internists, primary care physicians and pulmonologists should be aware of this condition in order to avoid delay in the diagnosis and institute appropriate therapy. The clinical features, pathophysiology, molecular genetics and medical treatment will be reviewed.

Correlation Between Anthropometric Measures and Biomarker Changes After Neoadjuvant Therapy With Tamoxifen or Anastrozole in Postmenopausal Women With Breast Cancer.

BACKGROUND: Epidemiological studies have reported positive associations between anthropometric measures and risk for developing breast cancers that express hormone receptors and associated mortality. However, the impact of nutritional status on the molecular response to endocrine therapy has yet to be described. METHODS: Body mass index (BMI), waist circumference (WC), hip circumference (HP), and waist-to-hip ratio (WHR) were measured in patients with invasive ductal carcinoma (IDC) before and after neoadjuvant treatment with either tamoxifen or anastrozole, and a possible correlation with prognostic factors, as estrogen receptor (ER), progesterone receptor (PgR), and proliferative index (Ki-67), was analyzed. Fifty-seven patients with palpable ER-positive IDC were randomized into three neoadjuvant treatment groups and received anastrozole or placebo or tamoxifen for twenty-one days. Biomarker status was obtained by comparing the immunohistochemical evaluation of samples collected before and after treatment, using the Allred scoring system. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS). RESULTS AND CONCLUSIONS: After treatment, the anastrozole group showed reduced ER and PgR expression (p < 0.05), and both the anastrozole and tamoxifen groups showed lower Ki-67 status. A significant reduction in PgR positivity (p < 0.05) was found in women with large WC and HC who were treated with anastrozole. Reduction in PgR positivity also tended to be associated with BMI (p = 0.09) in the anastrozole group. BMI, WC, HC and WHR correlated neither with biomarker levels in the tamoxifen and placebo groups nor with ER and Ki-67 status in the anastrozole group after primary endocrine treatment.

Effect of ozone/oxygen mixture on systemic oxidative stress and organic damage.

Ozone is a molecule of high energetic content. Its great oxidative power has been used in medicine for the treatment of several illnesses with a wide spectrum. The rectal insufflation with a mixture of ozone/oxygen is considered as a simple therapy, not painful, of low cost and practically free from adverse effects. Given its potential oxidation and lack of side-effects, the objective has been to know the state of different indexes of redox state in blood which may contribute to understanding the mechanism by which mixtures of ozone/oxygen administered by intrarectal route are able to exert actions on other organs. With this purpose female rabbits were used, distributed into four groups, and three doses of ozone/oxygen mixture were tested. When treatment was finished, the determination of pro-oxidant and antioxidant markers was carried out. Also indexes of organic damage were determined. Ozone doses administered to rabbits did not cause adverse effects and mortality did not show significant changes relative to tissue damages and they increased enzymes activities belonging to the first line antioxidant defences. The results demonstrate that ozone/oxygen mixture administered by rectal insufflations is innocuous and it is able to increase the antioxidant defense of the organism.

Minimum 5-year results in 96 consecutive hips treated with a tapered titanium stem system.

We performed total hip arthroplasty with single titanium stem in 96 consecutive, nonselected hips. All patients, regardless of bone type and shape, neck shaft angulation, or age, received the same implant. Patients were followed for a minimum of 5 years, and an independent radiographer evaluated the hips for ingrowth, subsidence, leg-length discrepancy, and remodeling. The average Harris Hip score was 96 points (range, 73-100 points) at final follow-up. Radiographically, all stems were ingrown. No stem had more than 3 mm of subsidence, and there were no leg-length discrepancies more than 5 mm. We concluded that this titanium stem is a versatile option for total hip arthroplasty in patients with a wide variety of demographic and femur characteristics.

Unicompartmental knee arthroplasty compares favorably to total knee arthroplasty in the same patient.

There are several surgical management options for medial knee arthritis, and it is often difficult to decide whether a unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA) is appropriate. Few studies have compared UKAs and TKAs in the same patient. We identified 23 patients with osteoarthritis who had a TKA on one side and a UKA on the other. The preoperative values of the 2 knees were not statistically different. Strict criteria were used to determine whether a UKA could be performed (functional anterior cruciate ligament, minimal deformity, and minimum changes in other compartments). Preoperative radiographs were reviewed to confirm that the knee undergoing TKA had medial compartment disease only. Knee Society scores, radiographic analysis, and patient preferences were recorded for all patients. Average follow-up was 46 months (range, 7.2-148 months) and 42 months (range, 11.5-59.8 months) for TKA and UKA, respectively. We found little or no difference in outcomes between the 2 procedures, except for an improved range of motion with the UKA compared with the TKA (123 degrees +/-9 degrees vs 119.8 degrees +/-7 degrees, respectively). Knee Society scores improved from 45.9 to 89.7 in UKA and from 42.4 to 90.3 in TKA. Of the 23 patients, 11 expressed no preference between either knee and 12 preferred the unicompartmental knee; no patient preferred the total knee. With appropriate patient selection, UKAs are a successful option for patients with osteoarthritis.

Midterm results of all-polyethylene tibial components in primary total knee arthroplasty.

Our goal was to determine the 7-year survivorship of a total knee arthroplasty system with all-polyethylene tibial components. From June 1996 to December 1997, 129 consecutive patients (177 knees) (>/=70 years old) underwent such primary arthroplasty at 2 centers in the United States. The 88 patients (120 knees) with 7 years or more of follow-up were evaluated radiographically and functionally. Average results included: Knee Society Score, 93.7 points (SD, 8.1); Knee Society function score, 68.9 points (SD, 27.6); range of motion, 119 degrees (SD, 10.9); osteolysis, 0%; stress shielding, 6.6%; progressive radiolucencies, 2.5%; Kaplan-Meier survivorship (revision), 99.4% (95% confidence intervals, 98.2%-100.0%). At midterm follow-up, an all-polyethylene tibial component proved to be an excellent surgical option for total knee arthroplasty in an elderly patient population.

Sarcoma sinovial monofásico primario de pulmón: reporte de un caso y revisión de la literatura / Single primary synovial sarcoma of the lung: a case report and review of the literature

El sarcoma sinovial es una entidad morfológica, clínica y genéticamente distinta y se puede apreciar en cualquier ubicación. Es un tumor mesenquimal de células fusiformes con una diferenciación epitelial variable. No existe una terapia estandarizada, generalmente el tratamiento es quirúrgico, con una resección total de la lesión, aplicándose en algunos casos radioterapia adyuvante. Los sarcomas sinoviales han mostrado quimiosensibilidad a la ifosfamida y a la doxorrubicina con una respuesta aproximada del 24 por ciento. Se presenta caso de una paciente de 32 años de edad quien presenta tumor en lóbulo inferior de pulmón izquierdo. Se le realizan estudios de extensión, paraclínicos y biopsia por punción dirigida por fluoroscopia que reportó neoplasia epitelial maligna poco diferenciada. Se diagnostica como cáncer de pulmón estadío I realizándose lobectomía inferior izquierda cuya biopsia y estudios inmunohistoquímicos diagnostica un sarcoma sinovial monofásico. Evoluciona satisfactoriamente refiriéndose a los servicios de oncología médica y radioterapia para tratamiento adyuvante.

Synovial Sarcoma is morphologic, clinical organization and genetically different and is possible to be appreciated in any location. Is mesenquimal tumor fusiform cell with variable epithelial differentiation. Treatment, standardized therapy does not exist; the treatment is generally surgical, with total resection of the injury, being applied in some cases adjuvant radiotherapy. Synovial sarcomas has shown chemo sensibility to ifosfamide one and doxorrubicin with an approximated answer of 24 %. A case of a patient of 32 years of age appears that presents displays tumor in inferior lobe of left lung. Studies of extension, paraclinics are made to him and biopsy by punction directed by fluoroscopy that reported neoplasia epithelial vitiates little differentiated. It is diagnosed as lung cancer stage I being made left inferior lobotomy whose inmunohystochemestry biopsy and studies diagnose Synovial sarcoma single-phase. It evolves satisfactorily talking about to the services of medical oncology and radiotherapy for adjuvant treatment.

Short-term mortality and its association with independent risk factors in adult spinal deformity surgery.

STUDY DESIGN: Retrospective review. OBJECTIVES: To determine postoperative mortality after adult spinal deformity surgery. To determine whether independent risk factors can predict mortality. SUMMARY OF BACKGROUND DATA: Although mortality after adult spinal surgery is reported to range from 0.03% to 3.52%, there is a general paucity of data on mortality and its associated risk factors after adult spinal deformity surgery. METHODS: Three hundred sixty-one adults with spinal deformity underwent 407 corrective procedures. For patients who died within 30 days of the procedure, the following risk factors were examined to determine if each could independently predict mortality: demographic information, American Society of Anesthesiologists' (ASA) classification, operative time, surgical approach, number of fusion levels, primary versus revision surgery, and intraoperative blood loss. RESULTS: Ten of the 407 procedures resulted in death (2.4% mortality): 1 intraoperatively secondary to cardiac ischemia, 3 secondary to sepsis/multiple organ failure, 2 each secondary to pulmonary embolus, uncal herniation/cerebral edema, and shock. The average preoperative ASA levels for patients who died and patients who survived were 3.0 and 2.3, respectively (P < 0.0001). Age, gender, operative time, surgical approach, number of fusion levels, revision status, and estimated blood loss did not have an independently significant correlation to mortality. CONCLUSION: There was a strong association (P < 0.0001) between increasing ASA class and increasing mortality. The other risk factors could not independently predict postoperative mortality within 30 days after adult spinal deformity surgery.

Pulmonary embolism after adult spinal deformity surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine the incidence and identify the associated risk factors of pulmonary embolism (PE) in patients who receive pharmacologic thromboprophylaxis after adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA: The risk of PE after adult spinal deformity surgery is reported to be as high as 2.2%. However, the incidence and associated risks of PE in the same patient population who receive postoperative pharmacologic thromboprophylaxis is unknown. METHODS: The study included 361 adult patients with spinal deformity who underwent 407 corrective spinal procedures for scoliosis, kyphosis, or kyphoscoliosis. The incidence of PE was determined and compared with a study (historical control) of similar patients undergoing similar surgery but without postoperative pharmacologic thromboprophylaxis. Their demographic information, American Society of Anesthesiologists score, operative time, surgical approach, surgical complexity, and intraoperative blood loss were also analyzed to determine the presence of associated risk factors. RESULTS: Despite universal pharmacologic thromboprophylaxis, 10 pulmonary emboli (2.4%) were diagnosed. Patients undergoing anterior spinal surgery were at a significantly higher risk than those undergoing posterior spinal surgery (P = 0.024). The right-side anterior approach was also associated with a significantly higher incidence of PE compared with the left-sided anterior approach (P = 0.018). Although the rate of PE after posterior spinal surgery did not differ from the historical control, the rate of PE after anterior surgery was reduced by 50% compared with the historical control. Age, gender, estimated blood loss, operative time, revision status, and the number of fusion levels were not significant variables for PE. There were 2 epidural hematomas requiring decompression (0.48%) and 1 wound hematoma (0.24%). CONCLUSION: Although pharmacologic thromboprophylaxis probably does not have a role after posterior spinal surgery, the data in this study suggest that it does lower the incidence of PE after anterior spinal surgery.