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At least 37 records · Page 2Linked to original sources
PubMed2003

Technical advances of pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension.

OBJECTIVE: To minimize the side-effects of circulatory arrest times and profound hypothermia in patients undergoing pulmonary thromboendarterectomy (PTE) for chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Between March 2000 and June 2002, 30 patients (in New York Heart Association (NYHA) class III or IV) were operated for CTEPH using our modified technique. It includes moderate hypothermic (28-32 degrees C), total cardiopulmonary bypass (CPB) and simultaneous selective antegrade cerebral perfusion and occlusion of the bronchial arteries by introducing an occlusive balloon catheter into the descending aorta. The preoperative pulmonary vascular resistance in the cohort was 873+/-248dynes/s/cm(-5). RESULTS: Mean total CPB, cross-clamp times and duration of anterograde cerebral perfusion were 132+/-40, 98+/-21 and 21+/-10min, respectively. Mean core temperature 29.5+/-1.9 degrees C. The duration of postoperative mechanical ventilatory support was 34+/-44h and the mean stay in the ICU was 5+/-9 days. Seven patients had mild to moderate lung reperfusion injury, one transient neurological dysfunction. Three patients (10%) died during their hospital stay, two for multiorgan failure and one for persistent pulmonary hypertension. All patients had a significant pulmonary hemodynamic improvement and all achieved NYHA class I (P<0.01) status 4 weeks after discharge, remaining stable at a median follow-up time of 16 months (range, 1-29 months) postoperatively. CONCLUSIONS: These technical advances improve neurological outcome, control back-bleeding from bronchial arteries and avoid prolonged rewarming phases in patients undergoing PTE.

Chronic Disease↗
PubMed1999

Technical advances and experimental devices for enteroscopy.

Enteroscopy remains the procedure in the gastrointestinal tract that is most inaccessible to endoscopy, and technical limitations severely impair the ability to advance and examine the small bowel reliably or completely. Push-type enteroscopy not only suffers limitations owing to looping in the stomach, but is intrinsically associated with increasing loss of transmission of force to the tip and consequent failure of advancement. Development is this area has been slow, partly owing to the limited clinical need compared with upper gastrointestinal endoscopy, and colonoscopy and consequent financial limitations imposed on further development. Practical and useful technical advances have been made, especially in push-type as well as sonde-type enteroscopy. These are reviewed briefly and are covered in other articles elsewhere in this issue.

Animals↗
PubMed2002

The Gray Lecture 2001: coming technical advances in radiation oncology.

PURPOSE: To review the current limits on the efficacy of radiotherapy (RT) due to technical factors and to assess the potential for major improvements in technology. METHODS AND MATERIALS: The method of this review was to assess the efficacy of current RT in general terms; strategies for improving RT; historical record of technological advances; rationale for further reductions of treatment volume; and importance of defining and excluding nontarget tissues from the target volume. The basis for the interest in proton beam RT is developed, and the relative dose distributions of intensity-modulated radiotherapy (IMRT) and intensity-modulated proton RT (IMPT) are discussed. The discovery of the proton and the first proposal that protons be used in RT is described. This is followed by a brief mention of the clinical outcome studies of proton RT. Likely technical advances to be integrated into advanced proton RT are considered, specifically, four-dimensional treatment planning and delivery. Finally, the increment in cost of some of these developments is presented. RESULTS: For definitive RT, dose limits are set by the tolerance of normal tissues/structures adjacent or near to the target. Using imaging fusion of CT, MRI, positron emission tomography, magnetic resonance spectroscopic imaging, and other studies will result in improved definition of the target margins. Proton beams are likely to replace photon beams because of their physical characteristics. Namely, for each beam path, the dose deep to the target is zero, across the target it is uniform, and proximal to the target it is less. Proton therapy can use as many beams, beam angles, noncoplanar, and dynamic, as well as static, intensity modulation, as can photon plans. The ability for much greater accuracy in defining the target position in space and then maintaining the target in a constant position in the radiation beam despite target movement between and during dose fractions will be possible. The cost of proton RT will be modestly higher than comparable high technology photon therapy. CONCLUSION: The technology of RT is clearly experiencing intense and rapid technical developments as pertains to treatment planning and dose delivery. It is predicted that radical dose RT will move to proton beam technology and that the treatment will be four dimensional (the fourth dimension is time). The impact will be higher tumor control probability and reduced frequency and severity of treatment-related morbidity.

Humans↗
PubMed2005

[Coming technical advances in radiation oncology].

PURPOSE: To review the current limits on the efficacy of radiotherapy (RT) due to technical factors and to assess the potential for major improvements in technology. METHODS AND MATERIALS: The method of this review was to assess the efficacy of current RT in general terms; strategies for improving RT; historical record of technological advances; rationale for further reductions of treatment volume; and importance of defining and excluding nontarget tissues from the target volume. The basis for the interest in proton beam RT is developed, and the relative dose distributions of intensity-modulated radiotherapy (IMRT) and intensity-modulated proton RT (IMPT) are discussed. The discovery of the proton and the first proposal that protons be used in RT is described. This is followed by a brief mention of the clinical outcome studies of proton RT. Likely technical advances to be integrated into advanced proton RT are considered, specifically, four-dimensional treatment planning and delivery. Finally, the increment in cost of some of these developments is presented. RESULTS: For definitive RT, dose limits are set by the tolerance of normal tissues/structures adjacent or near to the target. Using imaging fusion of CT, MRI, positron emission tomography, magnetic resonance spectroscopic imaging, and other studies will result in improved definition of the target margins. Proton beams are likely to replace photon beams because of their physical characteristics. Namely, for each beam path, the dose deep to the target is zero, across the target it is uniform, and proximal to the target it is less. Proton therapy can use as many beams, beam angles, noncoplanar, and dynamic, as well as static, intensity modulation, as can photon plans. The ability for much greater accuracy in defining the target position in space and then maintaining the target in a constant position in the radiation beam despite target movement between and during dose fractions will be possible. The cost of proton RT will be modestly higher than comparable high technology photon therapy. CONCLUSION: The technology of RT is clearly experiencing intense and rapid technical developments as pertains to treatment planning and dose delivery. It is predicted that radical dose RT will move to proton beam technology and that the treatment will be four dimensional (the fourth dimension is time). The impact will be higher tumor control probability and reduced frequency and severity of treatment-related morbidity.

Humans↗
PubMed1992

Angioscopy in endovascular surgery: recent technical advances to enhance intervention selection and failure analysis.

Recent technical and procedural modifications have greatly enhanced the usefulness of angioscopy during angioplasty. A pulsed irrigation system, proximal and distal blood flow control by pressure, and attention to sheath/vessel diameter ratio were incorporated into a study in which angioscopy was used for pretreatment assessment in 23 patients with symptomatic peripheral vascular disease presenting for initial (8 patients) evaluation or repeat treatment (15 patients) following a previous vascular procedure. Twenty-five lesions were examined with a 2.3 mm flexible angioscope equipped with an irrigating lumen; there were no complications attributable to angioscopy. The angioscope was useful in the characterization of lesions for selection of the recanalization technique. Lesions more amenable to initial atherectomy were visualized in 12 patients; 7 occlusions were successfully treated with laser/balloon angioplasty, with angioscopy assisting in probe and/or wire passage in 4 cases. Three late reocclusions were identified angioscopically as due solely to thrombosis, indicating the need for thrombolytic therapy. Angioscopy also identified 4 cases of incomplete recanalization despite a satisfactory arteriographic image. Angioscopy was also used to evaluate stenotic lesions unaccompanied by thrombus formation in patients previously treated with laser-assisted angioplasty. Histologic evaluation of the biopsied plaques identified intimal hyperplasia as the etiology, matching identically similar specimens harvested from a lesion treated with balloon dilation only.

Aged↗
PubMed1994

Technical advances in chest radiography.

Chest radiography is the most frequently performed radiologic imaging study and also one of the most challenging. The technical aspects of the conventional chest radiographic examination have been studied extensively, and the effects of various parameters on the quality of chest radiographs have been described. However, new approaches to image acquisition and display have been introduced in the last decade, and many circumvent the limitations of conventional screen-film studies. Thus, a number of practical issues must be considered in the selection of chest radiographic equipment for modern clinical practice. In this review, we describe several recent advances in both conventional and digital technologies that can improve the diagnostic quality of chest radiographs.

Humans↗
PubMedDate not supplied

MR cholangiography: technical advances and clinical applications.

Magnetic resonance (MR) cholangiography is a fast, accurate, noninvasive alternative to endoscopic retrograde cholangiography (ERC) in the evaluation of biliary tract disease. Technical improvements in imaging sequences (eg, half-Fourier rapid acquisition with relaxation enhancement) and use of phased-array coils allow high-quality imaging comparable to that available with ERC. In choledocholithiasis, common bile duct stones as small as 2 mm can be detected with MR cholangiography and appear as low-signal-intensity foci within the high-signal-intensity bile. MR cholangiography may help establish the diagnosis of malignant obstruction and is useful in the evaluation of patients in whom ERC was unsuccessful or incomplete. The role of MR cholangiography in the evaluation of intrahepatic duct disease continues to evolve. MR cholangiography plays a crucial role in evaluating postsurgical biliary tract alterations and can be used to demonstrate a variety of congenital anomalies of the biliary tract (eg, aberrant ducts, choledochal cysts, pancreas divisum). In addition, intentional or incidental imaging of the gallbladder with MR cholangiography can be used to identify calculi or help determine the presence and extent of neoplastic disease.

Biliary Tract↗
PubMed2003

Technical advances in radical retropubic prostatectomy techniques for avoiding complications. Part I: apical dissection.

Radical retropubic prostatectomy is currently the most widely used surgical treatment for localized prostate cancer. This once cumbersome procedure has developed technically over the last 20 years, reducing dramatically the associated complications and morbidity, e.g. blood loss, incontinence and impotence. Currently the operation is safe and is the best choice for eradicating localized disease, with little loss in quality of life. However, differences in reported outcomes indicate that there is still a need for standardization and continued efforts for surgical excellence. This review focuses on the crucial steps of the procedure, in two parts: the first covers apical dissection and the second the steps related to vesico-urethral anastomosis and the nerve-sparing procedure. This evaluation of the technical modifications aims to offer a choice, to vary the procedure according to the individual situation and thus improve the results. Current trends in surgical technique are also presented.

Dissection↗
PubMed1994

Recent technical advances in digital coronary angiography.

Digital coronary angiography systems are widely available in interventional catheterization laboratories. Although quantitative coronary angiography is an important and widely used endpoint for research and clinical trials, the capabilities of digital imaging now available are underused in clinical practice, and potential capabilities have not yet been developed or practically implemented. This paper reviews recently published technical developments in digital angiography and fluoroscopy, including radiographic dose reduction methods that have minimal impact on image quality, image processing and display methods for improving image quality, new algorithms and validations for quantitative coronary angiography, and methods for obtaining images of and analyzing the complete three-dimensional coronary tree. These advancements may lead to reduced radiation exposure, improved image quality, better automated stenosis quantitation programs, and extraction of new and useful kinds of information from the coronary angiogram.

Algorithms↗
PubMed2001

Technical advance: an automated device for cryofixation of specimens of electron microscopy using liquid helium.

Metal-contact rapid freezing using liquid helium is theoretically the best method for preserving the fine structure of living cells with high temporal resolution in preparation of tissue samples for electron microscopy. However, this method is not commonly used, because of its technical difficulty and low reproducibility. We have designed and constructed an automatic device which allows simple, rapid and reproducible preparation of high-quality electron microscopic specimens by the non-specialist. We assessed the quality of cryofixation in samples prepared using this device by examining the preservation of cellular ultrastructure in relation to distance from the freezing block, and found that the region within 10 microm of the metal-contact plane was fixed with the highest quality. We applied this device, in combination with freeze-substitution methods and immunocytochemical techniques, to two phenomena involving rapid movement of subcellular components: (1) active movement of subcellular structures in the papillar cells of stigma and (2) light-induced rapid subcellular translocation of phytochrome A. Considering the importance of understanding subcellular processes of living cells for molecular and cell biology, this device will be a useful tool for diverse biological applications in the near future.

Arabidopsis↗
PubMed1996

[Technical advances in the surgical management of thoracoabdominal aortic aneurysms].

Thoracoabdominal aortic aneurysmectomy ranks among the major cardiovascular surgical procedures. During the last two decades perioperative results have improved to the point that surgery should be discussed in the vast majority of patients seen with a thoracoabdominal aortic aneurysm. This progress is largely attributable to a variety of technical improvements including: aortic reconstruction using the graft inclusion technique, usually with direct reattachment of aortic branches to the prosthetic graft; distal aortic perfusion; selective use of deep hypothermic circulatory arrest in anatomically complex situations; preoperative visualization of arterial blood supply to the spinal cord using selective arteriography of intercostal and lumbar arteries. Current perioperative mortality is around 10% whereas the spinal cord complication rate is between 5% and 20% according to clinical and anatomical conditions. Future efforts should concentrate on the prevention of spinal cord complications.

Aortic Aneurysm, Abdominal↗
PubMed2000

Technical advances in multi-slice spiral CT.

X-ray computerised tomography (CT) scanning with continuous patient transport has been established under the name Spiral CT since several years as the standard clinical examination procedure. This technique has been improved continuously with respect to scan speed, temporal response and z-axis resolution by the use of latest technical developments: Rotation times up to 0.5 s and multi-row detector array systems. Today detector systems with M + 4 simultaneously measured slices are available. We report about recent progress of spiral CT reconstruction algorithms that are based on multi-slice data. It is demonstrated that the new technology not only provides significant reduction in overall scan times and thereby of the CT scanner?s X-ray tube load; beyond that, the new technology allows CT imaging of the beating heart with high level image quality in standard clinical routine.

Algorithms↗
PubMed2005

A review of technical advances in interventional magnetic resonance imaging.

Initial research in the development of interventional magnetic resonance (MR) imaging in the late 1980s and early to mid-1990s focused on pulse sequences, devices, and clinical applications. This focus was largely a result of the limited number of areas in which the academic research community leading the development could provide innovation on the MR systems of the time. However, during the past decade, computational power, higher bandwidth graphical displays, faster computer networks, improved pulse sequence architectures, and improved technical specifications have accelerated the pace of development on modern MR systems. Today, it is the combination of multiple system factors that are enabling the future of interventional MR. These developments, their impact on the field, and newly emerging applications are described.

Animals↗
PubMed2000

Laparoscopic extravesicular ureteral reimplantation for vesicoureteral reflux: recent technical advances.

Ureteral reimplantation is an effective treatment for primary vesicoureteral reflux. Recent efforts have been directed toward reducing the perioperative morbidity of open reimplantation. We have refined the technique of laparoscopic extravesical ureteral reimplantation with emphasis on minimal tissue dissection, achieving reliable detrusor closure, and downsizing ports and instruments. With our current technique, excellent results comparable to those of established open procedures are achieved, while postoperative discomfort and the recovery period are significantly reduced. The laparoscopic technique of ureteral reimplantation is described, with emphasis on key technical modifications crucial to the ease of performance and a successful outcome.

Cystoscopy↗
PubMed1992

Technical advances in the cytogenetic analysis of malignant tissues.

Successful cytogenetic analysis of malignant tissues using conventional techniques depends upon the presence of viable, dividing malignant cells in the sample, and the ability to obtain metaphase cells with good-quality chromosome banding. Even when these necessary conditions are met, many tumors have complex karyotypes that may be difficult to define completely or have subtle chromosomal abnormalities that are difficult to detect. Overall, determination of the karyotype of a malignant tissue is a time-consuming and labor-intensive process, and for some tumors, is associated with a significant technical failure rate. A number of new methods, which are reviewed in this article, have been developed recently that potentially will improve the speed, accuracy, and success rate of cytogenetic analysis of malignant tissues.

Cell Cycle↗
PubMed1983

Technical advances in the Senning operation.

Since March 1978, 59 patients with transposition of the great arteries (TGA) ranging in age from 2 months to 6 years have undergone the Senning operation. Forty-six patients (77.9%) had transposition with intact ventricular septum, 8 of them with patent ductus arteriosus; 8 patients (13.5%) had TGA with ventricular septal defect (VSD), 3 of them with previously performed banding; 4 patients (6.7%) had TGA with VSD and pulmonary stenosis (PS), and one (1.6%) had TGA with PS. Prior to correction, 38 cases had undergone a Rashkind septotomy and 15 had had a previous Blalock-Hanlon septectomy. During this time we have introduced some technical modifications of the original Senning operation: (A) right atrial incision, (B) large left atrial wall window, (C) infrasinal suture of the left atrial flap, (D) avoidance of damage to the hypothetical anterior atrioventricular conduction bundle, and recently, in 12 patients, we have used (E) an inverted left atrial appendage as an interatrial flap. There were 9 hospital deaths (15.2%) caused by low cardiac output (4 cases), severe hypoxemia and low cardiac output (4 cases) and one patient with pulmonary venous drainage obstruction died following reoperation. Two patients developed neurological complications that disappeared without sequela. Another complication was a right chylothorax (4 patients), which improved without the necessity of surgical repair. Eighteen patients developed a junctional rhythm for a period over 24 hours. We think that the technical modifications which we present here, partially contribute to improving the Senning operation.

Cardiac Output, Low↗
PubMed2004

Diagnostic coronary arteriography in the interventional era: a combination of technical advancements, new mental attitude, and improved skill.

Over the past 20 years, coronary angiography has taken many important steps forward in enhancing its ability to detect coronary artery disease. The major improvements in techniques and materials for percutaneous transluminal coronary angioplasty and stenting have led to the progressively widespread use of percutaneous revascularization in an increasing number of patients, including complex and multi-vessel disease. It is commonly believed that this improved interventional prospect has changed the way diagnostic coronary artery angiography is performed among the invasive and interventional cardiology community. The complete development of the coronary tree with more angulated views, the use of intracoronary nitrates in cases of moderate stenosis or spastic coronary trees and adequate balloon and stent sizing, improved magnification of acquisition, when a precise assessment of bifurcation or ostial stenosis is required or when a stented coronary segment is evaluated, and finally an interventional mental attitude, are an integral part of the invasive cardiologist's tools and skills matching the major technical improvements in equipment and materials.

Algorithms↗