Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and a major cause of chronic PH leading to right heart failure and death. Lung ventilation/perfusion ...scintigraphy is the screening test of choice; a normal scan rules out CTEPH. In the case of an abnormal perfusion scan, a high-quality pulmonary angiogram is necessary to confirm and define the pulmonary vascular involvement and prior to making a treatment decision. PH is confirmed with right heart catheterisation, which is also necessary for treatment determination. In addition to chronic anticoagulation therapy, each patient with CTEPH should receive treatment assessment starting with evaluation for pulmonary endarterectomy, which is the guideline recommended treatment. For technically inoperable cases, PH-targeted medical therapy is recommended (currently riociguat based on the CHEST studies), and balloon pulmonary angioplasty should be considered at a centre experienced with this challenging but potentially effective and complementary intervention.
Chronic Thromboembolic Pulmonary Hypertension Kim, Nick H., MD; Delcroix, Marion, MD; Jenkins, David P., MB BS ...
Journal of the American College of Cardiology,
12/2013, Volume:
62, Issue:
25
Journal Article, Conference Proceeding
Peer reviewed
Open access
Since the last World Symposium on Pulmonary Hypertension in 2008, we have witnessed numerous and exciting developments in chronic thromboembolic pulmonary hypertension (CTEPH). Emerging clinical data ...and advances in technology have led to reinforcing and updated guidance on diagnostic approaches to pulmonary hypertension, guidelines that we hope will lead to better recognition and more timely diagnosis of CTEPH. We have new data on treatment practices across international boundaries as well as long-term outcomes for CTEPH patients treated with or without pulmonary endarterectomy. Furthermore, we have expanded data on alternative treatment options for select CTEPH patients, including data from multiple clinical trials of medical therapy, including 1 recent pivotal trial, and compelling case series of percutaneous pulmonary angioplasty. Lastly, we have garnered more experience, and on a larger international scale, with pulmonary endarterectomy, which is the treatment of choice for operable CTEPH. This report overviews and highlights these important interval developments as deliberated among our task force of CTEPH experts and presented at the 2013 World Symposium on Pulmonary Hypertension in Nice, France.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela of acute pulmonary embolic disease and yet remains underdiagnosed. Although nonsurgical options for patients with ...CTEPH have become increasingly available, including pulmonary artery hypertensive medical therapy, surgical endarterectomy provides the most appropriate intervention as a potential cure for this debilitating disorder. This article summarizes the most recent outcomes of pulmonary endarterectomy at a single institution over the past 12 years, with emphasis on the surgical approach to segmental-level chronic thromboembolic disease. Methods More than 2,700 pulmonary endarterectomy operations have been performed at the University of California, San Diego Medical Center. Because of recent changes in the patient population and in surgical results, 1,500 patients with symptomatic chronic thromboembolic disease who underwent pulmonary endarterectomy between March 1999 and December 2010 were analyzed. The outcomes for the more recent 500 patients, compared with the previous 1,000 were studied. Results In-hospital mortality for the cohort of 1,000 patients (group 1) was 5.2% compared with 2.2% for the last 500 operations (group 2) ( p < 0.01). There was no mortality in the last 260 consecutive patients undergoing isolated pulmonary endarterectomy. More patients presented with segmental type III disease in the more recent 500 patients (21.4% versus 13.1%; p < 0.001). Between the 2 patient groups, there was a comparable decline in pulmonary vascular resistance (PVR) (group 1: 861.2 ± 446.2 to 94.8 ± 204.2 dynes/sec/cm−5 ; group 2: 719.0 ± 383.2 to 253.4 ± 148.6 dynes/sec/cm−5 ) and mean pulmonary artery (PA) pressures (group 1: 46.1 ± 11.4 to 28.7 ± 10.1 mm Hg; group 2: 45.5 ± 11.6 to 26.0 ± 8.4 mm Hg) after endarterectomy. Conclusions Despite a patient population with more distal disease, results continue to improve. Pulmonary endarterectomy for patients with CTEPH results in significant pulmonary hemodynamic improvement, with favorable outcomes achievable even in patients with distal segmental-level chronic thromboembolic disease.
Pulmonary thromboendarterectomy (PTE), also referred to as pulmonary endarterectomy, is the definitive treatment for chronic thromboembolic pulmonary hypertension (CTEPH). The true incidence of CTEPH ...is unknown and difficult to ascertain; however, most experts agree that approximately 4% to 5% of all patients who have an acute episode of pulmonary embolism (PE) will continue to develop CTEPH. Based on an incidence rate of about 0.1% for acute PE, this translates into a CTEPH incidence of approximately 10,000 to 15,000 annually in the United States alone. Furthermore, there are patients with CTEPH who have no history of prior PE or deep vein thrombosis, adding to the estimated number. Despite these facts, the disease remains significantly underdiagnosed, and currently there are only about 300 PTEs performed nationwide, the majority of which are done at the University of California, San Diego (UCSD) Health System. The technical aspects of the procedure can be somewhat challenging and require meticulous and complete dissection of the entire pulmonary vascular tree, with the patient under profound hypothermic circulatory arrest. However, the determination of true CTEPH patients and those who would benefit from surgery can also be challenging and relies heavily on the experience of the CTEPH team. In this article, we will highlight some key points about the disease and describe the surgical techniques of PTE.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Pulmonary endarterectomy is the treatment of choice for patients with operable chronic thromboembolic pulmonary hypertension (CTEPH) as it is potentially curative. In expert centers that conduct > 50 ...pulmonary endarterectomy procedures per year, peri- and post-surgical mortality rates are very low and long-term outcomes are excellent, with three-year post-operative survival of > 80%. Therapeutic decisions in CTEPH are based largely on the location of the arterial obstruction, with pulmonary endarterectomy for obstructions in main, lobar, and segmental vessels, and balloon pulmonary angioplasty and medical therapy for small-vessel disease. Medical therapy is also an option for patients with persistent/recurrent pulmonary hypertension after pulmonary endarterectomy or balloon pulmonary angioplasty. With increasing surgical experience and improvements in instruments and procedures, an increasing number of patients are now considered operable who would previously have been inoperable, including some patients with subsegmental disease. At our University (University of California San Diego), around 200 pulmonary endarterectomy procedures are performed every year and several advances have been developed, including resection of more distal disease, availability of pulmonary endarterectomy to patients previously considered to be at too high risk for surgery, improved management of post-pulmonary endarterectomy complications, and minimally invasive pulmonary endarterectomy. Pulmonary endarterectomy can be combined with other treatment modalities, including balloon pulmonary angioplasty, medical therapy for persistent/recurrent pulmonary hypertension after pulmonary endarterectomy, and medical therapy or balloon pulmonary angioplasty as bridging therapy before surgery. Data on these combinations are, however, limited. Combination treatment should therefore be considered on an individual patient basis. In the future, however, multimodal therapy with pulmonary endarterectomy, balloon pulmonary angioplasty, and/or medical therapy is likely to be an important treatment option for many patients.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Single-walled carbon nanotubes (SWCNTs) have been used in a variety of sensing and imaging applications over the past few years due to their unique optical properties. In the solution phase, SWCNTs ...are employed as near-infrared (NIR) fluorescence-based sensors of target analytes via modulations in emission intensity and/or wavelength. In an effort to lower the limit of detection, research has been conducted into isolating SWCNTs adhered to surfaces for potential single molecule analyte detection. However, it is known that SWCNT fluorescence is adversely affected by the inherently rough surfaces that are conventionally used for their observation (e.g., glass coverslip), potentially interfering with fluorescence-based analyte detection. Here, using a spin-coating method with thin films of alginate and SWCNTs, we demonstrate that a novel hydrogel platform can be created to investigate immobilized individual SWCNTs without significantly perturbing their optical properties as compared to solution-phase values. In contrast to the glass coverslip, which red-shifted DNA-functionalized (6,5)-SWCNTs by an average of 3.4 nm, the hydrogel platform reported emission wavelengths that statistically matched the solution-phase values. Additionally, the heterogeneity in the wavelength measurements, as determined from the width of created histograms, was reduced nearly by a factor of 3 for the SWCNTs in the hydrogel platform when compared to glass coverslips. Using long SWCNTs, i.e., those with an average length above the diffraction limit of our microscope, we show that a glass coverslip can induce optical heterogeneity along the length of a single SWCNT regardless of its surface functionalization. This is again significantly mitigated when examining the long SWCNTs in the hydrogel platform. Finally, we show that upon the addition of a model analyte (calcium chloride), the optical response can be spatially resolved along the length of a single SWCNT, enabling localized analyte detection on the surface of a single nanoscale sensor.
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IJS, KILJ, NUK, PNG, UL, UM
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Chronic thromboembolic pulmonary hypertension Hoeper, Marius M; Madani, Michael M; Nakanishi, Norifumi ...
The lancet respiratory medicine,
07/2014, Volume:
2, Issue:
7
Journal Article
Peer reviewed
Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but debilitating and life-threatening complication of acute pulmonary embolism. CTEPH results from persistent obstruction of pulmonary ...arteries and progressive vascular remodelling. Not all patients presenting with CTEPH have a history of clinically overt pulmonary embolism. The diagnostic work-up to detect or rule out CTEPH should include ventilation-perfusion scintigraphy, which has high sensitivity and a negative predictive value of nearly 100%. CT angiography usually reveals typical features of CTEPH, including mosaic perfusion, part or complete occlusion of pulmonary arteries, and intraluminal bands and webs. Patients with suspected CTEPH should be referred to a specialist centre for right-heart catheterisation and pulmonary angiography. Surgical pulmonary endarterectomy remains the treatment of choice for CTEPH and is associated with excellent long-term results and a high probability of cure. For patients with inoperable CTEPH, various medical and interventional therapies are being developed.
Wireless power transfer (WPT) systems' efficiency is significantly impacted by non-monotonic variations in the coupling coefficient. For very short distances or strong-coupling cases, the WPT ...efficiency is minimal at the natural resonant frequency, with two peaks around this frequency, known as the frequency splitting phenomenon. On the other hand, WPT capability decreases for long distances or weak coupling cases. Therefore, adaptive matching is required for WPT systems with varying distances, like wireless charging systems for electric vehicles (EVs). This paper first presents a detailed analysis of the frequency splitting phenomenon by studying the root locations of the WPT system's transfer function. Then, a real-time fixed-frequency adaptive impedance matching (IM) method is proposed, in which the amplitude and phase of the input impedance is estimated using the average active power, the average reactive power, and the amplitude of input voltage. Unlike traditional search-and-find techniques, the proposed method calculates the optimal IM network parameters only in a single iteration, which improves the convergent speed. A scaled-down 20-Watt prototype controlled by the TMSF2812 is fabricated and used to validate the effectiveness of the proposed method over a wide range of coil-to-coil distances.
Methyl methacrylate (MMA) monomer was grafted onto Low density Polyethylene by the direct method of radiation grafting. The effect of cohesive energy density of different organic solvents on the ...degree of grafting was investigated. It was found that the extent of grafting depends largely on the kind of solvent, in which the highest degree of grafting was achieved in the presence of dioxane, whereas the lowest degree of grafting occurred in the presence of methanol. This behaviour was attributed to the solubility parameters of the solvent, monomer and polymer. The change in structure of the LDPE graft copolymer films was characterized by scanning electron microscopy, X-ray diffraction, UV/vis absorption and thermogravimetric analysis. The X-ray diffraction results showed a decrease in the crystallinity of LDPE graft copolymer matrix at high degree of grafting. Studies were made on the UV-absorption edge, indirect allowed transitions with their optical energy gaps are determined. At the same time the Urbach energy was evaluated. The activation energy of the thermal decomposition was calculated according to Horowitz and Metzger method.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Post-surgical cardiac adhesions represent a significant problem during routine cardiothoracic procedures. This fibrous tissue can impair heart function and inhibit surgical access in reoperation ...procedures. Here, we propose a hydrogel barrier composed of oxime crosslinked poly(ethylene glycol) (PEG) with the inclusion of a catechol (Cat) group to improve retention on the heart for pericardial adhesion prevention. This three component system is comprised of aldehyde (Ald), aminooxy (AO), and Cat functionalized PEG mixed to form the final gel (Ald-AO-Cat). Ald-AO-Cat has favorable mechanical properties, degradation kinetics, and minimal swelling, as well as superior tissue retention compared to an initial Ald-AO gel formulation. We show that the material is cytocompatible, resists cell adhesion, and led to a reduction in the severity of adhesions in an in vivo rat model. We further show feasibility in a pilot porcine study. The Ald-AO-Cat hydrogel barrier may therefore serve as a promising solution for preventing post-surgical cardiac adhesions.
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