211 research outputs found
Prediction of fluid responsiveness using respiratory variations in left ventricular stroke area by transoesophageal echocardiographic automated border detection in mechanically ventilated patients.
BackgroundLeft ventricular stroke area by transoesophageal echocardiographic automated border detection has been shown to be strongly correlated to left ventricular stroke volume. Respiratory variations in left ventricular stroke volume or its surrogates are good predictors of fluid responsiveness in mechanically ventilated patients. We hypothesised that respiratory variations in left ventricular stroke area (DeltaSA) can predict fluid responsiveness.MethodsEighteen mechanically ventilated patients undergoing coronary artery bypass grafting were studied immediately after induction of anaesthesia. Stroke area was measured on a beat-to-beat basis using transoesophageal echocardiographic automated border detection. Haemodynamic and echocardiographic data were measured at baseline and after volume expansion induced by a passive leg raising manoeuvre. Responders to passive leg raising manoeuvre were defined as patients presenting a more than 15% increase in cardiac output.ResultsCardiac output increased significantly in response to volume expansion induced by passive leg raising (from 2.16 +/- 0.79 litres per minute to 2.78 +/- 1.08 litres per minute; p < 0.01). DeltaSA decreased significantly in response to volume expansion (from 17% +/- 7% to 8% +/- 6%; p < 0.01). DeltaSA was higher in responders than in non-responders (20% +/- 5% versus 10% +/- 5%; p < 0.01). A cutoff DeltaSA value of 16% allowed fluid responsiveness prediction with a sensitivity of 92% and a specificity of 83%. DeltaSA at baseline was related to the percentage increase in cardiac output in response to volume expansion (r = 0.53, p < 0.01).ConclusionDeltaSA by transoesophageal echocardiographic automated border detection is sensitive to changes in preload, can predict fluid responsiveness, and can quantify the effects of volume expansion on cardiac output. It has potential clinical applications
A study of machine learning and deep learning models for solving medical imaging problems
Application of machine learning and deep learning methods on medical imaging aims to create systems that can help in the diagnosis of disease and the automation of analyzing medical images in order to facilitate treatment planning. Deep learning methods do well in image recognition, but medical images present unique challenges. The lack of large amounts of data, the image size, and the high class-imbalance in most datasets, makes training a machine learning model to recognize a particular pattern that is typically present only in case images a formidable task.
Experiments are conducted to classify breast cancer images as healthy or non-healthy, and to detect lesions in damaged brain MRI (Magnetic Resonance Imaging) scans. Random Forest, Logistic Regression and Support Vector Machine perform competitively in the classification experiments, but in general, deep neural networks beat all conventional methods. Gaussian Naïve Bayes (GNB) and the Lesion Identification with Neighborhood Data Analysis (LINDA) methods produce better lesion detection results than single path neural networks, but a multi-modal, multi-path deep neural network beats all other methods. The importance of pre-processing training data is also highlighted and demonstrated, especially for medical images, which require extensive preparation to improve classifier and detector performance. Only a more complex and deeper neural network combined with properly pre-processed data can produce the desired accuracy levels that can rival and maybe exceed those of human experts
Reimplantation Valve Sparing Procedure in Type A Aortic Dissection: A Predictive Factor of Mortality and Morbidity?
Review and results of a survey about biosimilars prescription and challenges in the Middle East and North Africa region
BACKGROUND: Only drafts of regulatory guidelines for the registration of biosimilars are available in Lebanon. We analyzed the results of a regional survey conducted in Lebanon to understand the impact of different parameters on the acceptance and future prescription of biosimilars. We also reviewed the current situation of biosimilars around the world. The study surveyed healthcare professionals from the Arab countries, Iran, Belgium and Italy. Data about the participants’ specialty, country of residence, their knowledge about biosimilars, biosimilars’ prescription, price influence and the manufacturer’s credibility were collected. RESULTS: 117 questionnaires were completed and returned: 46 (39.3%) respondents were oncologists. 72 (61.5%) respondents were Lebanese, and the others from Egypt, Syria, Algeria, Iraq, Sudan, Jordan, Iran, Belgium and Italy. 77 (65.8%) respondents had knowledge about biosimilars, of whom 48 (62.3%) considered biosimilars as biologics that demonstrate bioequivalence with the original biodrug and have all preclinical and clinical trials equal to those already performed with the original biodrug. 74 (63.2%) out of 117 respondents agreed that biosimilars in the Arab and Middle Eastern market are already marketed. Among the 48 participants who prescribe biosimilars, the main prescription driver was the drug’s approval by the FDA and EMA (68.8%). 71 (60.7%) respondents considered that the main advantage of biosimilars is their lower price and 41 (35%) out of the 117 respondents declared that they should know in which country the drug has been tested/created before using it in their own country. 35% of the respondents thought that the cost of a treatment should not come before its effectiveness or safety/tolerance, given that the biosimilar will be less expensive than the reference drug. CONCLUSIONS: Biosimilars’ acceptance and use is increasing worldwide. Only few physicians are aware of biosimilars presence in the market and do prescribe them in Lebanon and the Arab region. This could be mainly explained by lack of confidence in efficacy, safety, manufacturing process and price of these products, and lack of clear legislation. Thus, WHO is finalizing a new guideline for similar biotherapeutic agents. This could be a starting point for the Lebanese government to support the authorization of biosimilars. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40064-016-3779-8) contains supplementary material, which is available to authorized users
Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair?
Type A aortic dissection (TAAD) is a serious condition requiring emergency surgical management. The main objective of the treatment is the patient survival. Thus, the surgeon has to perform a well-mastered surgical technique without extending the operative time and emphasizing operative risk. Nevertheless, patients with history of TAAD present long-term complications on the aorta, mainly aneurysmal evolution and dissection recurrence. In order to decrease the long-term excess mortality of this population, it is necessary to respect some rules during the surgery. Concerning the proximal segment of the ascending aorta, the aortic root has to be replaced by a composite graft (Bentall technique) or a valve sparing inclusion (David technique) when the dissection reaches the sinuses of Valsalva or when aortic valve regurgitation is observed. Concerning the distal segment of the ascending aorta, the distal anastomosis has to be performed without aortic clamping. Concerning the descending thoracic aorta, hybrid surgery should be performed on patients with malperfusion syndrome and patients with high risk factors for aneurysmal evolution
Prediction of fluid responsiveness using respiratory variations in left ventricular stroke area by transoesophageal echocardiographic automated border detection in mechanically ventilated patients
BackgroundLeft ventricular stroke area by transoesophageal echocardiographic automated border detection has been shown to be strongly correlated to left ventricular stroke volume. Respiratory variations in left ventricular stroke volume or its surrogates are good predictors of fluid responsiveness in mechanically ventilated patients. We hypothesised that respiratory variations in left ventricular stroke area (DeltaSA) can predict fluid responsiveness.MethodsEighteen mechanically ventilated patients undergoing coronary artery bypass grafting were studied immediately after induction of anaesthesia. Stroke area was measured on a beat-to-beat basis using transoesophageal echocardiographic automated border detection. Haemodynamic and echocardiographic data were measured at baseline and after volume expansion induced by a passive leg raising manoeuvre. Responders to passive leg raising manoeuvre were defined as patients presenting a more than 15% increase in cardiac output.ResultsCardiac output increased significantly in response to volume expansion induced by passive leg raising (from 2.16 +/- 0.79 litres per minute to 2.78 +/- 1.08 litres per minute; p < 0.01). DeltaSA decreased significantly in response to volume expansion (from 17% +/- 7% to 8% +/- 6%; p < 0.01). DeltaSA was higher in responders than in non-responders (20% +/- 5% versus 10% +/- 5%; p < 0.01). A cutoff DeltaSA value of 16% allowed fluid responsiveness prediction with a sensitivity of 92% and a specificity of 83%. DeltaSA at baseline was related to the percentage increase in cardiac output in response to volume expansion (r = 0.53, p < 0.01).ConclusionDeltaSA by transoesophageal echocardiographic automated border detection is sensitive to changes in preload, can predict fluid responsiveness, and can quantify the effects of volume expansion on cardiac output. It has potential clinical applications
Synchronous invasive ductal carcinoma of the breast and clear cell renal carcinoma with rare presentation and behaviour: A case report with a literature review
The presence of two or more primary tumours is a relatively uncommon phenomenon. Recently with the improvement of diagnostic modalities, such cases are increasingly reported in the literature. This paper presents a rare case of synchronous breast and renal tumour with unusual features including RCC metastasis to the duodenum and stomach, rapid recurrence of the tumour at the nephrectomy site, rapid renal cell carcinoma growth rate and the rare presence of syncytial-type giant cells in the renal cell tumour. Copyright: © the authors; licensee ecancermedicalscience. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Is there an optimal minimally invasive technique for left anterior descending coronary artery bypass?
<p>Abstract</p> <p>Background</p> <p>The aim of this retrospective study was to evaluate the clinical outcome of three different minimally invasive surgical techniques for left anterior descending (LAD) coronary artery bypass grafting (CABG): Port-Access surgery (PA-CABG), minimally invasive direct CABG (MIDCAB) and off-pump totally endoscopic CABG (TECAB).</p> <p>Methods</p> <p>Over a decade, 160 eligible patients for elective LAD bypass were referred to one of the three techniques: 48 PA-CABG, 53 MIDCAB and 59 TECAB. In MIDCAB group, Euroscore was higher and target vessel quality was worse. In TECAB group, early patency was systematically evaluated using coronary CT scan. During follow-up (mean 2.7 ± 0.1 years, cumulated 438 years) symptom-based angiography was performed.</p> <p>Results</p> <p>There was no conversion from off-pump to on-pump procedure or to sternotomy approach. In TECAB group, there was one hospital cardiac death (1.7%), reoperation for bleeding was higher (8.5% vs 3.7% in MIDCAB and 2% in PA-CABG) and 3-month LAD reintervention was significantly higher (10% vs 1.8% in MIDCAB and 0% in PA-CABG). There was no difference between MIDCAB and PA-CABG groups. During follow-up, symptom-based angiography (n = 12) demonstrated a good patency of LAD bypass in all groups and 4 patients underwent a no LAD reintervention. At 3 years, there was no difference in survival; 3-year angina-free survival and reintervention-free survival were significantly lower in TECAB group (TECAB, 85 ± 12%, 88 ± 8%; MIDCAB, 100%, 98 ± 5%; PA-CABG, 94 ± 8%, 100%; respectively).</p> <p>Conclusions</p> <p>Our study confirmed that minimally invasive LAD grafting was safe and effective. TECAB is associated with a higher rate of early bypass failure and reintervention. MIDCAB is still the most reliable surgical technique for isolated LAD grafting and the least cost effective.</p
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