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Dragos Predescu

Bio: Dragos Predescu is an academic researcher from McMaster University. The author has contributed to research in topics: Medicine & Pregnancy. The author has an hindex of 8, co-authored 29 publications receiving 323 citations. Previous affiliations of Dragos Predescu include McMaster Children's Hospital & University of Toronto.

Papers
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Journal ArticleDOI
TL;DR: Device closure of large perimembranous ventricular septal defects in infants and children with the Amplatzer Membranized VSD Occluder resulted in excellent closure rates but an unacceptably high rate of complete heart block.

134 citations

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TL;DR: In this article, the authors compared hybrid strategies for single ventricle palliation in terms of anatomic and physiologic growth stimuli to the pulmonary arteries (PA), hemodynamics, resource utilization, and survival.

60 citations

Journal ArticleDOI
TL;DR: A LAD prototype is presented that is designed to accommodate the different needs of term and preterm infants by permitting changing of the number of parallel-stacked microfluidic SOUs according to the actual body weight by testing the flow characteristics and gas exchange properties in vitro and under in vivo.
Abstract: A miniaturized oxygenator device that is perfused like an artificial placenta via the umbilical vessels may have significant potential to save the lives of newborns with respiratory insufficiency. Recently we presented the concept of an integrated modular lung assist device (LAD) that consists of stacked microfluidic single oxygenator units (SOUs) and demonstrated the technical details and operation of SOU prototypes. In this article, we present a LAD prototype that is designed to accommodate the different needs of term and preterm infants by permitting changing of the number of parallel-stacked microfluidic SOUs according to the actual body weight. The SOUs are made of polydimethylsiloxane, arranged in parallel, and connected though 3D-printed polymeric interconnects to form the LAD. The flow characteristics and the gas exchange properties were tested in vitro using human blood. We found that the pressure drop of the LAD increased linearly with flow rate. Gas exchange rates of 2.4-3.8 μL/min/cm(2) (0.3-0.5 mL/kg/min) and 6.4-10.1 μL/min/cm(2) (0.8-1.3 mL/kg/min) for O2 and CO2 , respectively, were achieved. We also investigated protein adsorption to provide preliminary information on the need for application of anticoagulant coating of LAD materials. Albumin adsorption, as measured by gold staining, showed that surface uptake was evenly distributed and occurred at the monolayer level (>0.2 μg/cm(2) ). Finally, we also tested the LAD under in vivo conditions using a newborn piglet model (body weight 1.65-2.0 kg). First, the effect of an arteriovenous bypass via a carotid artery-to-jugular vein shortcut on heart rate and blood pressure was investigated. Heart rate and mean arterial blood pressure remained stable for extracorporeal flow rates of up to 61 mL/kg/min (101 mL/min). Next, the LAD was connected to umbilical vessels (maximum flow rate of 24 mL/min [10.4 mL/kg/min]), and O2 gas exchange was measured under hypoxic conditions (Fi O2 = 0.15) and was found to be 3.0 μL/min/cm(2) . These results are encouraging and support the feasibility of an artificial placental design for an LAD.

52 citations

Journal Article
TL;DR: The neoadjuvant and adjuvant therapy indications guided and depending on genetic analysis included in the diagnostic and treatment algorithm as well as the strategy for cases surveillance are listed in the journal.
Abstract: Gastrointestinal stromal tumors (GIST) are rare tumors of the digestive tract, with an incidence of about 1.5 per 100,000/year. Clinical features may vary depending on location, size and aggressiveness. The diagnosis is confirmed by immunohistochemistry tests that identify CD 117 or DOG1 (typical receptors/markers for most GISTs) at the level of biopsy specimen. The treatment of localized GIST is based primarily on the surgery, while for metastatic GIST the targeted therapy with tyrosine kinase inhibitors represents the current standard. The neoadjuvant and adjuvant therapy indications guided and depending on genetic analysis included in the diagnostic and treatment algorithm as well as the strategy for cases surveillance are listed in the journal. All these data obtained from the literature have been integrated in a practical experience of 19 cases of GIST, operated in the clinic in the last 10 years for which we have proposed an adapted diagnostic algorithm.

18 citations

Journal Article
TL;DR: Due to the need for good mobilization, arterial ligations should be adjusted and modified depending on the particular vascular distribution, to maintain a sufficient blood flow in the marginal artery, in order to reach the colic sections and the straight arteries near them.
Abstract: Introduction No matter the reconstructive technique, the fundamental concepts in visceral reconstruction have as main grounds the mandatory vascular support for the graft replacement. Individual vascular particularities can influence or even oblige the surgeon to choose a certain procedure. This is why the vascularization is beyond doubt the dominant factor in mobilizing the colon for reconstruction. Material and method Our arteriographic study entails an investigation upon the vascularization pattern of the two main sources that participate in the arterial irrigation of the colon via the emerging vessels: superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). We did not consider certain patients upon a specific criterion; also, we did not exclude any patients due to various reasons. We took into account 49 patients as study group, all of them having registered into the clinic for a reconstructive technique, throughout the years from 2000 to 2010. From 1981 to 2012 there have been 187 reconstructive techniques performed due to post caustic pathology. From a total of 49 patients, 11 had suffered major abdominal surgeries, 5 of which had had unsuccessful reconstructive attempts. Results Out of the 49 patients on whom we have performed the exploration, arteriography showed a favorable situation for reconstruction in 31 of them. In the other 18 patients anomalies or atypical distributions were identified, in 5 of the SMA and in 13 of the IMA, respectively. Operative decision was modified in 22 patients. One important thing to note from the point of view of the segment to be moved: we had no graft necrosis in patients with preoperative arteriographic examination. Conclusions Due to the need for good mobilization, arterial ligations should be adjusted and modified depending on the particular vascular distribution, to maintain a sufficient blood flow in the marginal artery, in order to reach the colic sections and the straight arteries near them.

14 citations


Cited by
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Journal ArticleDOI
TL;DR: The concepts of OOAC are introduced and its application to the construction of physiological models, drug development, and toxicology from the perspective of different organs are reviewed.
Abstract: The organ-on-a-chip (OOAC) is in the list of top 10 emerging technologies and refers to a physiological organ biomimetic system built on a microfluidic chip. Through a combination of cell biology, engineering, and biomaterial technology, the microenvironment of the chip simulates that of the organ in terms of tissue interfaces and mechanical stimulation. This reflects the structural and functional characteristics of human tissue and can predict response to an array of stimuli including drug responses and environmental effects. OOAC has broad applications in precision medicine and biological defense strategies. Here, we introduce the concepts of OOAC and review its application to the construction of physiological models, drug development, and toxicology from the perspective of different organs. We further discuss existing challenges and provide future perspectives for its application.

351 citations

Journal ArticleDOI
TL;DR: The engineering of a bioinspired elastic and biocompatible hydrophobic light-activated adhesive (HLAA) that achieves a strong level of adhesion to wet tissue and is not compromised by preexposure to blood is described.
Abstract: Currently, there are no clinically approved surgical glues that are nontoxic, bind strongly to tissue, and work well within wet and highly dynamic environments within the body. This is especially relevant to minimally invasive surgery that is increasingly performed to reduce postoperative complications, recovery times, and patient discomfort. We describe the engineering of a bioinspired elastic and biocompatible hydrophobic light-activated adhesive (HLAA) that achieves a strong level of adhesion to wet tissue and is not compromised by preexposure to blood. The HLAA provided an on-demand hemostatic seal, within seconds of light application, when applied to high-pressure large blood vessels and cardiac wall defects in pigs. HLAA-coated patches attached to the interventricular septum in a beating porcine heart and resisted supraphysiologic pressures by remaining attached for 24 hours, which is relevant to intracardiac interventions in humans. The HLAA could be used for many cardiovascular and surgical applications, with immediate application in repair of vascular defects and surgical hemostasis.

243 citations

Journal ArticleDOI
01 Nov 2018-Europace
TL;DR: In this article, a position paper was designed to state the art in management of young individuals with Congenital Heart Disease (CHD) and arrhythmias, including pharmacological treatment, catheter ablation, and device therapy.
Abstract: The population of patients with congenital heart disease (CHD) is continuously increasing with more and more patients reaching adulthood. A significant portion of these young adults will suffer from arrhythmias due to the underlying congenital heart defect itself or as a sequela of interventional or surgical treatment. The medical community will encounter an increasing challenge as even most of the individuals with complex congenital heart defects nowadays become young adults. Within the past 20 years, management of patients with arrhythmias has gained remarkable progress including pharmacological treatment, catheter ablation, and device therapy. Catheter ablation in patients with CHD has paralleled the advances of this technology in pediatric and adult patients with structurally normal hearts. Growing experience and introduction of new techniques like the 3D mapping systems into clinical practice have been particularly beneficial for this growing population of patients with abnormal cardiac anatomy and physiology. Finally, device therapies allowing maintanence of chronotropic competence and AV conduction, improving haemodynamics by cardiac resynchronization, and preventing sudden death are increasingly used. For pharmacological therapy, ablation procedures, and device therapy decision making requires a deep understanding of the individual pathological anatomy and physiology as well as detailed knowledge on natural history and long-term prognosis of our patients. Composing expert opinions from cardiology and paediatric cardiology as well as from non-invasive and invasive electrophysiology this position paper was designed to state the art in management of young individuals with congenital heart defects and arrhythmias.

179 citations