Science.gov

Sample records for angioplastie und stentimplantation

  1. MedlinePlus: Angioplasty

    MedlinePlus

    ... Angioplasty updates by email What's this? GO GO MEDICAL ENCYCLOPEDIA Angioplasty and stent - heart - discharge Angioplasty and stent placement - heart Balloon angioplasty - short segment Coronary artery balloon angioplasty - slideshow ...

  2. Coronary Angioplasty

    MedlinePlus

    ... page from the NHLBI on Twitter. What Is Percutaneous Coronary Intervention? Español Percutaneous (per-ku-TA-ne-us) coronary intervention (PCI), commonly known as coronary angioplasty (AN-jee- ...

  3. Angioplasty and stent placement -- peripheral arteries

    MedlinePlus

    Percutaneous transluminal angioplasty - peripheral artery; PTA - peripheral artery; Angioplasty - peripheral arteries; Iliac artery -angioplasty; Femoral artery - angioplasty; Popliteal artery - angioplasty; Tibial artery - angioplasty; Peroneal artery - ...

  4. Ultrasonic angioplasty

    NASA Astrophysics Data System (ADS)

    Siegel, Robert J.

    1990-08-01

    Over the past 3 years we have developed a percutaneous ultrasonic angioplasty device and recently applied it in human peripheral arteries. This paper describes some of the background preceding the development of intravascular ultrasound for arterial recanalization. The chronology of our development of ultrasonic angioplasty is discussed from in vitro studies on atherosclerotic plaque to in vivo studies in canine models with differing types of arterial occlusions (thrombotic fibrotic calcific-atherosclerotic) and to initial human application. SPIE Vol. 1321 Modern Technologies Applied to Medical Practice (1989) / 69

  5. Laser Angioplasty

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The principal method of dealing with coronary artery blockage is bypass surgery. A non-surgical alternative available to some patients is balloon angioplasty. For several years, medical researchers have been exploring another alternative that would help a wider circle of patients than the balloon treatment and entail less risk than bypass surgery. A research group is on the verge of an exciting development: laser angioplasty with a 'cool' type of laser, called an excimer laser, that does not damage blood vessel walls and offers non-surgical cleansing of clogged arteries with extraordinary precision. The system is the Dymer 200+ Excimer Laser Angioplasty System, developed by Advanced Intraventional Systems. Used in human clinical tests since 1987, the system is the first fully integrated 'cool' laser capable of generating the requisite laser energy and delivering the energy to target arteries. Thirteen research hospitals in the U.S. have purchased Dymer 200+ systems and used them in clinical trials in 121 peripheral and 555 coronary artery cases. The success rate in opening blocked coronary arteries is 85 percent, with fewer complications than in balloon angioplasty. Food and Drug Administration approval for the system is hoped for in the latter part of 1990. * Advanced Intraventional Systems became Spectranetics in 1994 and discontinued the product.

  6. Angioplasty and stent placement - heart

    MedlinePlus

    ... angioplasty; Coronary artery angioplasty; Percutaneous transluminal coronary angioplasty; Heart artery dilatation ... to carefully guide the catheter up into your heart and arteries. Dye will be injected into your ...

  7. Angioplasty and stent placement - carotid artery

    MedlinePlus

    Carotid angioplasty and stenting; CAS; Angioplasty - carotid artery; Carotid artery stenosis - angioplasty; ... Carotid angioplasty and stenting (CAS) is done using a small surgical cut. Your surgeon will make a surgical cut in your groin after using some ...

  8. Balloon angioplasty - short segment

    MedlinePlus Videos and Cool Tools

    Angioplasty is a procedure to open narrowed or blocked arteries caused by deposits of plaque. If the blockage is not major, ... passage for the blood to flow through. Typically, a device called a stent is placed within the ...

  9. Angioplasty and Vascular Stenting

    MedlinePlus

    ... the narrowed vein is also needed. narrowing in dialysis fistula or grafts. When there is decreased flow ... the graft or fistula making it inadequate for dialysis, angioplasty is generally the first line of treatment. ...

  10. Balloon catheter coronary angioplasty

    SciTech Connect

    Angelini, P.

    1987-01-01

    The author has produced a reference and teaching book on balloon angioplasty. Because it borders in surgery and is performed on an awake patient without circulatory assistance, it is a complex and demanding procedure that requires thorough knowledge before it is attempted. The text is divided into seven sections. The first section describes coronary anatomy and pathophysiology, defines the objectives and mechanisms of the procedure and lists four possible physiologic results. The next section describes equipment in the catheterization laboratory, catheters, guidewires and required personnel. The following section is on the procedure itself and includes a discussion of examination, testing, technique and follow-up. The fourth section details possible complications that can occur during the procedure, such as coronary spasms, occlusion, thrombosis, perforations and ruptures, and also discusses cardiac surgery after failed angioplasty. The fifth section details complex or unusual cases that can occur. The sixth and seventh sections discuss radiation, alternative procedures and the future of angioplasty.

  11. Percutaneous transluminal coronary angioplasty (PTCA)

    MedlinePlus Videos and Cool Tools

    Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive procedure to open up blocked coronary arteries, allowing blood to circulate unobstructed to the heart muscle. The procedure ...

  12. Angioplasty and stent - heart - discharge

    MedlinePlus

    ... discharge; PTCA - discharge; Percutaneous transluminal coronary angioplasty - discharge; Heart artery dilatation - discharge ... the blood vessels that supply blood to your heart. You may have had a heart attack or ...

  13. Coronary artery balloon angioplasty - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100160.htm Coronary artery balloon angioplasty - series To use the sharing features ... out of 9 Normal anatomy Overview The coronary arteries supply blood to the heart muscle. The right ...

  14. Coronary angioplasty guidewire technology.

    PubMed

    McDermott, E A

    1987-01-01

    The technology of coronary guide wires has advanced rapidly since Simpson and Robert performed the first angioplasty with a movable guidewire system in 1981. The technology involved in engineering guidewires encompasses three areas: (1) selection of materials, (2) design of the configuration, and (3) development of the construction process to fabricate the guidewire. Each of these areas must be considered concurrently; that is, the functional effects of manufacturing a wire must be considered along with material selection and configuration design. Another critical area is functional testing to ensure safe and effective performance of the guidewire in the clinical setting and to confirm its functional limits. Research is directed continually toward advancing existing guidewire technology to improve functional performance and develop more efficient manufacturing processes. Additionally under development are new guidewire devices incorporating microsensors and fiberoptics to provide real-time feedback. Advances in technology require miniaturization of guidewire components and application of new materials and processes to manufacture new designs. PMID:2964145

  15. Angioplasty - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Angioplasty URL of this page: https://medlineplus.gov/languages/angioplasty.html Other topics A-Z A B ...

  16. Angioplasty - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Angioplasty URL of this page: https://www.nlm.nih.gov/medlineplus/languages/angioplasty.html Other topics A-Z A B ...

  17. Focused force angioplasty Theory and application

    SciTech Connect

    Solar, Ronald J.; Ischinger, Thomas A

    2003-03-01

    Focused force angioplasty is a technique in which the forces resulting from inflating an angioplasty balloon in a stenosis are concentrated and focused at one or more locations within the stenosis. While the technique has been shown to be useful in resolving resistant stenoses, its real value may be in minimizing the vascular trauma associated with balloon angioplasty and subsequently improving the outcome.

  18. Laser angioplasty for cardiovascular disease

    NASA Astrophysics Data System (ADS)

    Okada, Masayoshi

    2005-07-01

    Recently, endovascular interventions such as balloon angioplasty, atherectomy and the stenting method, except for conventional surgery have been clinically employed for the patients with atheromatous plaques of the peripheral- and the coronary arteries, because the number of patients with arteriosclerosis is now increasing in the worldwide. Among these procedures, restenoses after endovascular interventions have been remarkably disclosed in 20-40 % of the patients who underwent percutaneous coronary interventions. Thus, there are still some problems in keeping long-term patency by means of endovascular techniques such as balloon angioplasty and atherectomy (1, 2). For reduction of these problems , laser angioplasty using Argon laser was applied experimentally and clinically. Based on excellent experimental studies, laser was employed for 115 patients with stenotic ,or obstructive lesions occluding more thasn 75 % of the peripheral and the coronary arteries angiographycally.

  19. Septic endarteritis following percutaneous transluminal coronary angioplasty.

    PubMed

    Kardaras, F G; Kardara, D F; Rontogiani, D P; Mpourazanis, I A; Flessas, L P

    1995-01-01

    We report a case of bacterial arteritis of the external iliac artery complicated by mycotic aneurysm following coronary angioplasty. To our knowledge, this is the first reported instance of arterial wall infection caused by coronary angioplasty at a distance from the insertion site equal to the length of the sheath. PMID:7728855

  20. [Uncommon indications for coronary angioplasty].

    PubMed

    Vojácek, J; Krupicka, P; Aschermann, M; Holm, F; Humhal, J

    1993-07-01

    During the period between March 16, 1989 and October 7, 1992 at the Second Medical Clinic of the First Medical Faculty, Charles University Prague a total of 173 coronary angioplasties were performed. With expanding experience and greater availability of controllable super thin conductors and balloon catheters with a small profile, gradually the indication criteria of coronary angioplasty were extended. In 93.1% of patients simple balloon dilatation of a significant stenosis of the coronary arteries was performed and in 6.9% before dilatation in addition an attempt of recanalization of a chronic occlusion of the coronary artery was made. In 74% of the patients one coronary stenosis was dilated, in 16.7% several stenoses, in 1.2% of the patients a covered stenosis of the trunk of the left coronary was dilated and in the same number an aortocoronary bypass was performed. Even in the group of patients where only one coronary stenosis was dilated the type B coronary affection according to the classification ACC/AHA predominated and the same applied to the entire group of patients. PMID:8372458

  1. Sleep Apnea Tied to Complications After Angioplasty

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159391.html Sleep Apnea Tied to Complications After Angioplasty Nightly breathing ... 15, 2016 WEDNESDAY, June 15, 2016 (HealthDay News) -- Sleep apnea may increase the risk of serious complications ...

  2. Angioplasty and stent placement - peripheral arteries - discharge

    MedlinePlus

    ... Supplements Videos & Tools Español You Are Here: Home → ... the sharing features on this page, please enable JavaScript. You had procedure that used a balloon catheter to open a narrowed vessel (angioplasty) that ...

  3. Sleep Apnea Tied to Complications After Angioplasty

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_159391.html Sleep Apnea Tied to Complications After Angioplasty Nightly breathing ... 15, 2016 WEDNESDAY, June 15, 2016 (HealthDay News) -- Sleep apnea may increase the risk of serious complications ...

  4. Outpatient angioplasty: 4-year experience in one practice.

    PubMed Central

    Payne, S. P.; Stanton, A.; Travers, P.; Glenn, D.; Hanel, K. C.

    1997-01-01

    Angioplasty is often performed as an inpatient procedure after preliminary angiography. In order to increase efficiency and patient comfort we introduced a policy of performing angioplasty for chronic leg ischaemia as an outpatient whenever possible, using duplex scanning to select suitable lesions. This paper examines the safety and feasibility of this policy over a 4-year period. We prospectively assessed 168 consecutive cases which were planned for outpatient angioplasty from a total of 190 cases undergoing angioplasty and found full agreement between duplex scanning and angiography in 92%. Six patients (4%) developed complications of angioplasty requiring admission and another five were admitted for unexpected organisational reasons. Thus, the complication rate of outpatient angioplasty was 4%. All complications were noted at the time of angioplasty with no unexpected readmissions. Angioplasty for leg ischaemia is feasible and safe to perform as an outpatient using duplex scanning to select appropriate cases. PMID:9326123

  5. Percutaneous angioscopy after excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Nakamura, Fumitaka; Kvasnicka, Jan; Geschwind, Herbert J.; Uchida, Yasumi

    1992-08-01

    Angioscopy has proved to provide more detailed information on lesion morphology before and after interventional procedures than angiography. Therefore, to evaluate the effects of laser angioplasty, angioscopy was performed in five patients with peripheral or coronary vascular disease who underwent excimer laser angioplasty. The excimer laser was operated at 308 nm, 135 nsec, 25 Hz, and 40 - 60 mJ/mm2 and was coupled into multifiber wire-guided catheters of 1.4 to 2.0 mm diameter for coronary lesions and 2.2 mm for peripheral lesions. There were three coronary (one left anterior descending, one circumflex, one right coronary artery) and two peripheral (one common iliac artery, one superficial femoral artery) lesions. Angioscopy was successfully performed before and after laser ablation without any complications in all five lesions. The characteristics of angioscopic findings after excimer laser angioplasty consisted of flaps, fractures of plaques, and abundant tissue remnants. There was no apparent thermal injury. Recanalized channels were small and irregular. These results indicate that (1) angioscopy is effective and safe for evaluation of lesion morphology after laser angioplasty, (2) laser ablation does not result in thermal injury, and (3) irregular channels after recanalization and abundant tissue remnants may explain the suboptimal results after laser angioplasty.

  6. Video-assisted thoracoscopic bronchoplasty/pulmonary arterial angioplasty.

    PubMed

    Xu, Xin; Huang, Jun; Pan, Hui; Chen, Hanzhang; He, Jianxing

    2016-03-01

    Thoracoscopic bronchoplasty combined with pulmonary arterial angioplasty can be particularly challenging. In the past, it was often done by using a conventional incision or hybrid video-assisted small incision. In recent years, anecdotal articles have described the application of thoracoscopic bronchoplasty/pulmonary arterial angioplasty. This chapter will describe the details associated with thoracoscopic bronchoplasty/pulmonary arterial angioplasty. PMID:27076953

  7. Video-assisted thoracoscopic bronchoplasty/pulmonary arterial angioplasty

    PubMed Central

    Xu, Xin; Huang, Jun; Pan, Hui; Chen, Hanzhang

    2016-01-01

    Thoracoscopic bronchoplasty combined with pulmonary arterial angioplasty can be particularly challenging. In the past, it was often done by using a conventional incision or hybrid video-assisted small incision. In recent years, anecdotal articles have described the application of thoracoscopic bronchoplasty/pulmonary arterial angioplasty. This chapter will describe the details associated with thoracoscopic bronchoplasty/pulmonary arterial angioplasty. PMID:27076953

  8. [Subintimal angioplasty and diabetic foot revascularisation].

    PubMed

    Pierret, Charles; Tourtier, Jean-Pierre; Bordier, Lise; Blin, Emmanuel; Duverger, Vincent

    2011-01-01

    Diabetic wounds foot are responsible for 5-10% minor or major amputation in France. In fact, amputation risk of lower limbs is 15-30% higher for diabetic patients. University of Texas classification (UT) is the reference for diabetic foot wound. It distinguish non ischemic and ischemic wound with more amputation. If ischaemia is combined, revascularization may be considered for salvage of the limb. Some revascularization techniques are well known: as surgical by-pass, angioplasty with or without stent, or hybrid procedures with the both. Subintimal angioplasty is a more recent endovascular technique, in assessment for old patients who are believed to be unsuitable candidates for conventional by-pass or angioplasty. PMID:20980123

  9. Tandem balloon catheter for coronary angioplasty.

    PubMed

    Finci, L; Meier, B; Steffenino, G; Rutishauser, W

    1986-01-01

    The Tandem balloon catheter is a triple lumen steerable catheter for coronary angioplasty with two separately inflatable balloons of different diameters. Indications and results of 26 consecutive patients treated with a Tandem balloon catheter are reviewed. Adequate distal pressure measurements were obtained in 71% of the cases. In ten patients, the Tandem balloon catheter was selected for two stenoses in different segments of the same coronary artery. Angioplasty was successful for all lesions in five and for at least the strategic lesions in five patients (in one only after changing to a single-balloon catheter). In the seven patients with stenoses in two different coronary arteries of various calibers, angioplasty was successful for both vessels in three and for one vessel in four patients. In the six patients with a very tight stenosis, where the Tandem balloon catheter was selected to predilate with the small balloon, the procedure was technically successful in all, but there was a myocardial infarction in one patient. In the three patients with a chronic total occlusion, where the stiffness of the Tandem balloon was the reason for selection, one recanalization was successful. The Tandem balloon catheter provides a handy tool for complex coronary angioplasty. It offers comparable ease in manipulation and pressure transmission and may save time, money, and radiation exposure by avoiding catheter exchanges. PMID:2949848

  10. Restenosis After Balloon Angioplasty for Cerebral Vasospasm

    SciTech Connect

    Sedat, J. Chau, Y.; Popolo, M.; Gindre, S.; Rami, L.; Orban, J. C.

    2009-03-15

    Transluminal balloon dilatation for symptomatic vasospasm after subarachnoid hemorrhage is effective, and clinical studies have shown that it achieves long-lasting dilatation of spastic cerebral arteries. Delayed arterial renarrowing has not been reported. Here we report the case of a 58-year-old woman who presented asymptomatic and permanent restenosis after angioplasty for cerebral vasospasm.

  11. Arterio-Ureteric Fistula Following Iliac Angioplasty

    SciTech Connect

    Aarvold, Alexander; Wales, Lucy Papadakos, Nikolaos; Munneke, Graham; Loftus, Ian; Thompson, Matt

    2008-07-15

    Arterio-ureteric fistulae are rare but can be associated with significant morbidity and mortality. We describe a novel case in which an arterio-ureteric fistula occurred as a complication following external iliac artery angioplasty and stenting, in a patient who had undergone previous pelvic surgery, radiotherapy, ureteric stenting, and urinary diversion surgery. Prompt recognition enabled successful endovascular management using a covered stent.

  12. [Coronary angioplasty in elderly patients].

    PubMed

    Liistro, Francesco; Colombo, Antonio

    2002-01-01

    the two different strategies (5-year survival rate: 85.7% for the coronary artery bypass grafting group vs 81.4% for the percutaneous revascularization group) with a clear benefit in favor of surgery only in diabetic patients. The only constant difference is the need of a repeat intervention which is significantly higher for the percutaneous approach. Furthermore, the introduction of newer percutaneous devices suitable for the recanalization of totally occluded coronary arteries could increase the completeness of the revascularization achieved with the percutaneous approach with a positive effect on the long-term outcome. These considerations could be "out of time" if the results obtained with the use of drug-eluting stents observed in selected patient populations will be confirmed in larger trials and in routine clinical practice. Whereas the advantages of the percutaneous versus the surgical approach in the elderly have not been fully clarified in patients with stable or unstable angina, primary angioplasty appears to be a very promising strategy in old patients with acute myocardial infarction. The improved clinical success with percutaneous revascularization in the elderly (acute mortality in patients > 85 years: 28.4% reperfused vs 38.5% not reperfused; p = 0.001) has to be related to the use of stents and to IIb/IIIa antagonists. In conclusion, when an old patient needs myocardial revascularization, the percutaneous approach should, in our opinion, be considered the treatment of choice in subjects either with stable or unstable angina and in those with acute myocardial infarction. At present, surgical revascularization provides better results in diabetic patients. The advent of drug-eluting stents may change many of the current limitations of percutaneous revascularization and further expand the use of this strategy. PMID:11899566

  13. Paget-Schroetter Syndrome Treated with Cutting-Balloon Angioplasty

    SciTech Connect

    Gosling, J.; Nayeemuddin, M.; Cowling, M.; Pherwani, A.; Asquith, J.

    2012-06-15

    Here, a case of Paget-Schroetter Syndrome in a 25-year-old guitar player is reported. After thrombolysis, conventional angioplasty failed to dilate the underlying subclavian stenosis both before and after first-rib excision with scalenus anterior and medius division. For the third attempt at angioplasty, a cutting balloon was used, which immediately produced a good result. Venography at 4-year follow-up showed no restenosis and no functional deficit. This case report demonstrates that cutting-balloon angioplasty may be considered when conventional balloon fails and may have greater durability than conventional balloon angioplasty in the treatment of Paget-Schroetter syndrome.

  14. Paget-Schroetter syndrome treated with cutting-balloon angioplasty.

    PubMed

    Gosling, J; Nayeemuddin, M; Cowling, M; Pherwani, A; Asquith, J

    2012-06-01

    Here, a case of Paget-Schroetter Syndrome in a 25-year-old guitar player is reported. After thrombolysis, conventional angioplasty failed to dilate the underlying subclavian stenosis both before and after first-rib excision with scalenus anterior and medius division. For the third attempt at angioplasty, a cutting balloon was used, which immediately produced a good result. Venography at 4-year follow-up showed no restenosis and no functional deficit. This case report demonstrates that cutting-balloon angioplasty may be considered when conventional balloon fails and may have greater durability than conventional balloon angioplasty in the treatment of Paget-Schroetter syndrome. PMID:21845509

  15. A new catheter system for coronary angioplasty.

    PubMed

    Simpson, J B; Baim, D S; Robert, E W; Harrison, D C

    1982-04-01

    A new catheter system has been designed for percutaneous transluminal coronary angioplasty. An independently movable, flexible-tipped guide wire within the balloon dilation catheter facilitates selection of the involved vessel. This guide wire can be passed slowly and carefully beyond the coronary stenosis, permitting safe advancement of the balloon catheter. After testing in animal and cadaver hearts, this system was used in 53 patients (56 stenoses) with single vessel coronary artery disease, with an overall primary success rate of 64 percent. In the last 41 of these 56 cases, use of a balloon catheter with a smaller deflated diameter increased the success rate to 73 percent. In patients with lesions of the left anterior descending coronary artery, the success rate was 89 percent. Three (6 percent) of the 53 patients had complications during coronary arterial dilation that necessitated emergency coronary arterial bypass graft surgery. There were no procedure-related or late cardiac deaths. During the mean follow-up period of 8 months (range 1 to 21), there were one late death (of noncardiac causes) and no late myocardial infarctions. Clinical status was persistently improved in 31 of the 36 patients who had successful dilation. The remaining five patients experienced restenosis at the angioplasty site and return of angina pectoris within 3 months of dilation. Two of these patients had repeat coronary angioplasty with restoration of asymptomatic status, and three had elective coronary bypass graft surgery. PMID:6461241

  16. Percutaneous transluminal angioplasty of radiation-induced arterial stenoses

    SciTech Connect

    Guthaner, D.F.; Schmitz, L.

    1982-07-01

    A case of atherosclerosis resulting from previous irradiation was successfully treated using percutaneous transluminal angioplasty for recanalization of the vessel. Irradiation may result in extensive perivascular fibrosis around an area of arterial narrowing; percutaneous transluminal angioplasty appears to be the method of choice for treatment of such lesions.

  17. Primary Infrainguinal Subintimal Angioplasty in Diabetic Patients

    SciTech Connect

    Bargellini, Irene Petruzzi, Pasquale; Scatena, Alessia; Cioni, Roberto; Cicorelli, Antonio; Vignali, Claudio; Rizzo, Loredana; Piaggesi, Alberto; Bartolozzi, Carlo

    2008-07-15

    The aim of this study was to prospectively evaluate technical and clinical results of infrainguinal subintimal angioplasty in a series of diabetic patients with limb-threatening ischemia. From July 2003 to December 2007, 60 consecutive diabetic patients (M/F = 41/19; mean age, 69.4 {+-} 9.4 years) with Fontaine stage IV critical limb ischemia, not suitable for surgical recanalization, underwent primary infrainguinal subintimal angioplasty. The technical success, perioperative morbidity and mortality, and clinical success (defined by ulcer healing) were evaluated. Kaplan-Meier life-table analysis was obtained for cumulative clinical success, limb salvage, and survival rates. The procedure was technically successful in 55 of 60 (91.7%) patients; in 5 cases we were not able to achieve a reentry. Periprocedural mortality was 5% (3 patients); three patients (5%) required major amputation periprocedurally. Mean follow-up was 23 months (range, 0-48 months). On an intention-to-treat basis, the limb salvage rate was 93.3% (56/60 patients); ulcer healing was observed in 45 of 60 (75%) patients and it was significantly (p < 0.05) associated with serum creatinine and HbA1c levels, diabetes duration, and infrapopliteal recanalization. One- and three-year cumulative survival rates were 91.5% and 83.1%, respectively; serum creatinine levels, patient age, and clinical success were significant predictors of survival. In conclusion, infrainguinal primary subintimal angioplasty is a safe and effective treatment in diabetic patients with limb-threatening ischemia not suitable for surgical recanalization. This procedure is aimed to create a 'temporary bypass' that facilitates ulcer healing.

  18. Percutaneous transluminal angioplasty: radiological-pathological correlation

    SciTech Connect

    Saffitz, J.E.; Totty, W.G.; McClennan, B.L.; Gilula, L.A.

    1981-12-01

    Radiological and pathological assessment of the degree and extent of arterial injury caused by balloon angioplasty was performed in 20 renal arteries obtained at autopsy. Intact arteries were studied angiographically before and after dilatation and then examined histologically. Both normal and diseased arteries were subjected to varying degrees of dilatation. Damage ranged from minimal inimal disruption to major tears of the muscular media. Equivalent dilatory force created greater damage in the distal (muscular) than in the proximal (elastic) portion of the renal artery. There was no evidence of plaque remodling or compression.

  19. Primary coronary angioplasty in patients with acute myocardial infarction.

    PubMed Central

    Popma, J J; Chuang, Y C; Satler, L F; Kleiber, B; Leon, M B

    1994-01-01

    In some patients with acute myocardial infarction, thrombolytic therapy may be limited by its failure to reperfuse the occluded artery, by recurrent ischemia (despite initially successful reperfusion), and by major hemorrhagic complications. Primary coronary angioplasty may circumvent these limitations. This article reviews the results of primary angioplasty reported in patients with myocardial infarction and makes recommendations for its use. The review includes pertinent articles found in the English language literature from July 1987 to July 1993 on MEDLINE. Nonrandomized series of primary angioplasty in acute myocardial infarction have demonstrated high procedural success rates (86% to 99%) and infrequent recurrent ischemia (4%). Two randomized trials comparing primary angioplasty and thrombolytic therapy have shown that primary angioplasty results in lower mortality, less recurrent ischemia, shorter length of hospital stay, and improved left ventricular function. Two other randomized studies have shown little benefit from primary angioplasty on myocardial salvage, recurrent ischemia, or ventricular function. One major limitation of primary angioplasty is that it requires 24-hour availability of a catheterization laboratory and experienced surgical personnel. Primary angioplasty may be the preferred approach in patients with extensive myocardial infarction who have immediate (< 120 min) access to a cardiac catheterization laboratory with experienced personnel. Patients having 1) contraindications to thrombolytic therapy, 2) cardiogenic shock, 3) prior coronary bypass surgery, or 4) "stuttering" onset of pain may also benefit from primary angioplasty. Poor candidates for this procedure are those with a small myocardial infarction, those in whom undue delays in access to a cardiac catheterization facility would be expected, or those with complex coronary anatomy, including left main coronary artery disease. PMID:8061539

  20. Thermoelastic analysis of high-pressure angioplasty balloons.

    PubMed

    Eaton-Evans, J; Dulieu-Barton, J M; Little, E; Brown, I

    2006-04-01

    Failures in angioplasty balloons are investigated using typical destructive techniques. The material properties of moulded balloons are derived from tensile tests and used to establish the reasons for failure of the balloons. Thermoelastic stress analysis is used to determine the stress distribution in the balloons, and a means of interpreting the data to derive actual stresses is described. The departure from linear elastic behaviour in the angioplasty balloons is identified using thermoelastic analysis. The results from the thermoelastic analysis are discussed and compared with those from the destructive tests, and the thermoelastic technique is shown to be a potential new means for non-destructive analysis of angioplasty balloons. PMID:16808075

  1. Clopidogrel Responsiveness in Patients Undergoing Peripheral Angioplasty

    SciTech Connect

    Pastromas, Georgios Spiliopoulos, Stavros Katsanos, Konstantinos Diamantopoulos, Athanasios Kitrou, Panagiotis Karnabatidis, Dimitrios Siablis, Dimitrios

    2013-12-15

    Purpose: To investigate the incidence and clinical significance of platelet responsiveness in patients receiving clopidogrel after peripheral angioplasty procedures. Materials and Methods: This prospective study included patients receiving antiplatelet therapy with clopidogrel 75 mg after infrainguinal angioplasty or stenting and who presented to our department during routine follow-up. Clopidogrel responsiveness was tested using the VerifyNow P2Y12 Assay. Patients with residual platelet reactivity units (PRU) {>=} 235 were considered as nonresponders (NR group NR), whereas patients with PRU < 235 were considered as normal (responders [group R]). Primary end points were incidence of resistance to clopidogrel and target limb reintervention (TLR)-free survival, whereas secondary end points included limb salvage rates and the identification of any independent predictors influencing clinical outcomes. Results: In total, 113 consecutive patients (mean age 69 {+-} 8 years) with 139 limbs were enrolled. After clopidogrel responsiveness analysis, 61 patients (53.9 %) with 73 limbs (52.5 %) were assigned to group R and 52 patients (46.1 %) with 66 limbs (47.5 %) to group NR. Mean follow-up interval was 27.7 {+-} 22.9 months (range 3-95). Diabetes mellitus, critical limb ischemia, and renal disease were associated with clopidogrel resistance (Fisher's exact test; p < 0.05). According to Kaplan-Meier analysis, TLR-free survival was significantly superior in group R compared with group NR (20.7 vs. 1.9 %, respectively, at 7-year follow-up; p = 0.001), whereas resistance to clopidogrel was identified as the only independent predictor of decreased TLR-free survival (hazard rate 0.536, 95 % confidence interval 0.31-0.90; p = 0.01). Cumulative TLR rate was significantly increased in group NR compared with group R (71.2 % [52 of 73] vs. 31.8 % [21 of 66], respectively; p < 0.001). Limb salvage was similar in both groups. Conclusion: Clopidogrel resistance was related with

  2. Comparison of angioscopic findings between coronary balloon and laser angioplasty

    NASA Astrophysics Data System (ADS)

    Larrazet, Fabrice S.; Dupouy, Patrick J.; Dubois-Rande, Jean Luc; Hirosaka, Akira; Kvasnicka, Jan; Geschwind, Herbert J.

    1994-07-01

    Percutaneous intracoronary angioscopy was used to study the morphological changes occurring in coronary arteries after balloon or laser angioplasty. Angioscopy is thought to provide details on the coronary vessel lumen and the inner wall. Coronary lesion were studied in 44 patients with a 4.5 F Imagecath angioscope before and after each interventional procedure. Balloon and laser angioplasty were performed on 21 (group I) and 23 patients (group II), respectively. There was no difference in age, sex, or angiographic lesion appearance before the procedure between the two groups. Circumferential visualization of the target lesion was successfully completed in 17 group I patients and 19 group II patients. A larger lumen than that observed at control was seen in all 17 dilatation patients and in 13 of the 19 laser patients. Tissue remnants were observed in all balloon and laser patients. Laser irradiation resulted in characteristic sharp edged craters. Dissection was identified in 2 of 19 before versus 9 of 19 patients after balloon angioplasty (p<0.05) and in 0 of 23 before versus 4 of 23 patients after laser angioplasty. Subintimal hemorrhage was observed in 3 of 19 before versus 11 of 19 patients after balloon angioplasty (p<0.05) and in 2 of 23 before versus 4 of 23 patients after laser angioplasty. The frequency of hemorrhage was higher in the post balloon group than in the post laser group (11 of 19 versus 4 of 23, respectively, p<0.02). Angioscopy provides valuable information on lesion morphology after coronary interventions. Balloon dilation results in a high rate of dissection and subintimal hemorrhage. Laser angioplasty is able to ablate obstructing tissue and results in a lower rate of subintimal hemorrhage than balloon dilatation.

  3. Excimer laser coronary angioplasty: relative risk analysis of clinical results

    NASA Astrophysics Data System (ADS)

    Bittl, John A.

    1992-08-01

    Reports of successful use of excimer laser coronary angioplasty for complex coronary artery disease abound, yet firm indications for its use have not been defined. We attempted to treat 858 coronary stenoses in 764 consecutive patients (mean age 61 years; range 32 - 91 years; 75% men; 76% with Class III or IV angina) with excimer laser angioplasty at 308 nm. Successful treatment was achieved in 86% of patients, as indicated by angioplasty, we used relative risk analysis. This showed that certain angiographic features, such as lesions at a vessel bifurcation (odds ratio, OR equals 0.46; 95% confidence interval 0.23, 0.88; P equals 0.017;) or in a tortuous segment (OR equals 0.54; 95% CI equals 0.34, 0.88; P equals 0.041), have decreased likelihood of clinical success. On the other hand, ostial stenoses (OR equals 1.06; 95% CI equals 0.44, 2.56, P equals 0.903) and saphenous vein graft lesions (OR equals 2.17; 95% CI equals 0.98, 4.82; P equals 0.051) have acceptable success rates. Diffuse disease (> 20 mm), total occlusions and calcified lesions were treated as successfully as all other lesion types. Successful treatment with excimer laser coronary angioplasty was also achieved in almost all patients (15/16) who had a prior unsuccessful attempt at balloon angioplasty in the lesion was crossed with a guidewire yet resists either balloon catheter passage or full dilatation. Follow-up angiography was obtained in 70% of eligible patients. Angiographic restenosis, defined by > 50% stenosis, was seen in 60% of patients. Relative risk analysis showed an increased risk of restenosis when adjunctive balloon angioplasty was not used (OR equals 1.68; 95% CI equals 1.02, 2.28; P equals 0.039). Other variables known to affect the outcome of balloon angioplasty, such as lesion length or stenosis in degenerated saphenous vein bypass graft, did not influence the

  4. Angioplasty and Stenting for Intracranial Stenosis

    PubMed Central

    IZUMI, Takashi; IMAMURA, Hirotoshi; SAKAI, Nobuyuki; MIYACHI, Shigeru

    2014-01-01

    Of the patients enrolled in the Japanese Registry of Neuroendovascular Therapy (JR-NET), a surveillance study in Japanese, 1133 patients who underwent intracranial percutaneous transluminal angioplasty (PTA)/stenting for intracranial stenosis during the period from 2005 to 2009 were investigated. A technical success was achieved in 98.3% of the patients, and 70.5% and 7.5% had a residual stenosis of < 30% and ≥ 50%, respectively. The incidence of ischemic complications and hemorrhagic complications was as low as 7.7% and 2.5%, respectively, but tended to increase in patients who underwent stenting. While a significant correlation with ischemic complications was observed in previously untreated patients and patients who underwent stenting followed by post-dilatation, a significant correlation with hemorrhagic complications was observed in patients who received emergency treatment and those treated between 24 hours and 14 days of the onset. Flexible intracranial stents are expected to contribute to improvement in the treatment outcome. PMID:24390191

  5. Intravascular ultrasound imaging following balloon angioplasty.

    PubMed

    Tobis, J M; Mahon, D J; Moriuchi, M; Honye, J; McRae, M

    1991-01-01

    Despite its long history and reliability, contrast angiography has several inherent limitations. Because it is a two-dimensional projection image of the lumen contour, the wall thickness cannot be measured and the plaque itself is not visualized. This results in an underestimation of the amount of atherosclerotic disease by angiography. An assessment of atherosclerosis could be improved by an imaging modality: (1) that has an inherent larger magnification than angiography and (2) that directly visualizes the plaque. Intravascular ultrasound fulfils these criteria. This presentation will provide evidence that intravascular ultrasound may prove complimentary or even superior to angiography as an imaging modality. Intravascular ultrasound demonstrates excellent representations of lumen and plaque morphology of in vitro specimens compared with histology. There is very close intraobserver and interobserver variability of measurements made from intravascular ultrasound images. Phantom studies of stenoses in a tube model demonstrate that angiography can misrepresent the severity of stenosis when the lumen contour is irregular and not a typical ellipse, whereas intravascular ultrasound reproduces the cross-sectional morphology more accurately since it images the artery from within. In vitro studies of the atherosclerotic plaque tissue characteristics compare closely with the echo representation of fibrosis, calcification, and lipid material. In addition, in vitro studies of balloon angioplasty demonstrate that intravascular ultrasound accurately represents the changes in the structure of artery segments following balloon dilatation. PMID:1833473

  6. Mechanical and acoustic analysis in ultrasonic angioplasty

    NASA Astrophysics Data System (ADS)

    Detwiler, Paul W.; Watkins, James F.; Rose, Eric A.; Ratner, A.; Vu, Louis P.; Severinsky, J. Y.; Rosenschein, Uri

    1991-05-01

    The goal of this study was to investigate the relationship between ultrasonic tissue ablation and passive mechanical elasticity. Experience with ultrasonic angioplasty in experimental settings (in-vivo and in-vitro) together with clinical experience in peripheral vascular disease is reported. A model composed exclusively of a hydroxyproline ballistic gelatin matrix showed a negative correlation between material elasticity and the rate of ultrasonic ablation. This model provided a means of studying the effects of collagen content on ablation, exclusive of other biologic components. Ballistic gelatin ablation (mg/sec) was found to increase logarithmically with decreasing protein concentration over the range studied (20.00 to 1.25%). Ablation as a function of gelatin elasticity behaved in a similar manner. Temperature of the material ablated was also demonstrated to affect the rate of ablation. We conclude that the previously reported differences in ablation between thrombi and blood vessel are predictable based on the large difference in their mechanical elasticity, and that this difference provides a wide margin of safety.

  7. Cutting Balloon Angioplasty Versus Standard Balloon Angioplasty for Failing Infra-inguinal Vein Grafts: Comparative Study of Short- and Mid-Term Primary Patency Rates

    SciTech Connect

    Vikram, Raghunandan; Ross, Rose A.; Bhat, Rajesh; Griffiths, Gareth D.; Stonebridge, Peter A.; Houston, J. Graeme; Chakraverty, S.

    2007-07-15

    Purpose. To evaluate the results of a recent change in practice in our institution using cutting balloon angioplasty instead of standard balloon angioplasty as the primary treatment for failing infra-inguinal vein bypass grafts. Methods. In this nonrandomized cohort study with a historical control, failing infra-inguinal vein grafts were identified at duplex surveillance or clinical examination. Patients had confirmatory arteriography and balloon angioplasty at the same attendance. Interventions proximal or distal to the graft itself and prosthetic grafts were not included. Patients were entered into a duplex graft surveillance program. Initial assessment of technical success was duplex or improvement 4-6 weeks after the primary angioplasty. Results. Twenty-seven consecutive patients were treated with standard balloon angioplasty, then 11 consecutive patients were treated with cutting balloon angioplasty. Initial technical success was 74% for the standard balloon versus 82% for the cutting balloon. The primary patency rate at 6 months was 16/26 (62%) for standard balloon angioplasty and 8/10 (80%) for cutting balloon angioplasty (p = 0.44). The primary patency rate at 12 months was 9/25 (36%) for standard balloon angioplasty and 5/10 (50%) for cutting balloon angioplasty (p = 0.47). Conclusion. The use of cutting balloons for primary angioplasty of infra-inguinal vein grafts offers no definite advantage over standard balloon angioplasty in this institution or compared with patency rates after standard balloon angioplasty reported elsewhere. Larger multicenter studies would be required to demonstrate whether there was any real difference between the two techniques.

  8. Early hospital discharge after direct angioplasty for acute myocardial infarction.

    PubMed

    Hanlon, J T; Combs, D T; McLellan, B A; Railsback, L; Haugen, S

    1995-07-01

    To determine the feasibility and safety of early hospital discharge after myocardial infarction, we reviewed a 3-yr experience with direct angioplasty: 204 patients had direct angioplasty with in-hospital mortality of 3.4%. Of these patients, 125 were discharged < 5 days after infarction and 98% of these were available for 30-day follow-up. There was one early death (0.8% mortality), two early readmissions without complications, and three late readmissions. Thus early hospital discharge a mean of 3.4 days after infarction can be achieved in > 60% of patients undergoing direct angioplasty with no significant early complications and excellent 30-day survival (99.2%). PMID:7553817

  9. Aspirin inhibition of platelet deposition at angioplasty sites: demonstration by platelet scintigraphy

    SciTech Connect

    Cuningham, D.A.; Kumar, B.; Siegel, B.A.; Gilula, L.A.; Totty, W.G.; Welch, M.J.

    1984-05-01

    In-111 platelet scintigraphy was used to evaluate the effects of prior aspirin administration on the accumulation of In-111-labeled autologous platelets at sites of arterial injury resulting from iliac, femoral, or popliteal transluminal angioplasty in a nonrandomized study of 17 men. The degree of platelet localization at angioplasty sites was significantly less in nine men who had received aspirin in varying doses within the 4 days before angioplasty than in eight men who had not received aspirin for at least two weeks. The results suggest that aspirin treatment before angioplasty limits the early platelet deposition at the angioplasty site in men.

  10. The case for angioplasty in patients with symptomatic intracranial atherosclerosis.

    PubMed

    McTaggart, Ryan A; Marks, Michael P

    2014-01-01

    Intracranial atherosclerotic disease (ICAD) is likely the most common cause of stroke worldwide and remains highly morbid even with highly monitored medical therapy. Recent results of the SAMMPRIS trial, which randomized patients to stenting plus aggressive medical management versus aggressive medical management alone have shown that additional treatment of intracranial atherosclerotic lesions with the Wingspan stent is inferior to aggressive medical management alone. In light of these results, there has been renewed interest in angioplasty alone to treat symptomatic ICAD. This article will briefly review the natural history of ICAD and discuss the possible future for endovascular treatment of ICAD with primary intracranial angioplasty in appropriately selected patients. PMID:24782816

  11. The Case for Angioplasty in Patients with Symptomatic Intracranial Atherosclerosis

    PubMed Central

    McTaggart, Ryan A.; Marks, Michael P.

    2014-01-01

    Intracranial atherosclerotic disease (ICAD) is likely the most common cause of stroke worldwide and remains highly morbid even with highly monitored medical therapy. Recent results of the SAMMPRIS trial, which randomized patients to stenting plus aggressive medical management versus aggressive medical management alone have shown that additional treatment of intracranial atherosclerotic lesions with the Wingspan stent is inferior to aggressive medical management alone. In light of these results, there has been renewed interest in angioplasty alone to treat symptomatic ICAD. This article will briefly review the natural history of ICAD and discuss the possible future for endovascular treatment of ICAD with primary intracranial angioplasty in appropriately selected patients. PMID:24782816

  12. Carotid Artery Stenosis with Acute Ischemic Stroke: Stenting versus Angioplasty

    PubMed Central

    Villwock, Mark R.; Padalino, David J.; Deshaies, Eric M.

    2015-01-01

    Background When a patient with carotid artery stenosis presents emergently with acute ischemic stroke, the optimum treatment plan is not clearly defined. If intervention is warranted, and open surgery is prohibitive, endovascular revascularization may be performed. The use of stents places the patient at additional risk due to their thrombogenic potential. The intent of this study was to compare outcomes following endovascular approaches (angioplasty alone vs. stent) in the setting of acute stroke. Methods We extracted a population from the National Inpatient Sample (2012) and the Nationwide Inpatient Sample (2003–2011) composed of patients with carotid artery stenosis with infarction that were admitted nonelectively and received endovascular revascularization. Patients treated with mechanical thrombectomy or thrombolysis were excluded. Categorical variables were compared between treatment groups with Chi-squared tests. Binary logistic regression was performed to evaluate mortality and iatrogenic stroke while controlling for age, case severity, and comorbidity burden. Results About 6,333 admissions met our criteria. A majority were treated via stenting (89%, n = 5,608). The angioplasty-alone group had significantly higher mortality (9.0% vs. 3.8%, p < 0.001) and iatrogenic stroke rate (3.9% vs. 1.9%, p < 0.001) than the stent group. The adjusted odds ratios of mortality and iatrogenic stroke for patients treated with angioplasty alone were 1.953 (p < 0.001) and 1.451 (p = 0.105), respectively, in comparison to patients treated with carotid stenting. Conclusion Multivariate analysis found the risk of mortality to be elevated following angioplasty alone. This may represent selection bias, but it also may indicate that symptomatic patients with stroke suffer from severe stenosis and unstable plaques that would benefit from stent placement. These results would caution angioplasty alone as an arm of a future randomized trial involving this severely burdened patient

  13. Applicability of laser to assist coronary balloon angioplasty.

    PubMed

    Lee, G; Chan, M C; Ikeda, R M; Rink, J L; Dukich, J; Peterson, L; Lee, K K; Reis, R L; Mason, D T

    1985-12-01

    Severe atherosclerotic obstructed coronary artery disease (CAD) may preclude passage of a balloon catheter for transluminal coronary angioplasty (TCA). Since lasers have been shown to effectively vaporize CAD plaque, the initial application of laser to effect a lumen large enough to accommodate the angioplasty catheter for further dilatation was explored. Eleven postmortem human CAD segments which did not permit passage of a 1.33 mm shaft diameter angioplasty catheter were studied. Argon laser radiation (14 to 90 J) transmitted via 400 micron core diameter quartz fiber onto the stenotic channel of 0.58 mm created a vaporized lumen of 1.77 mm (mean increase of 1.31 +/- 0.25 mm, p less than 0.001). The laser procedure allowed the balloon angioplasty catheter to be pushed into the stenosis. TCA was then performed (7 atm, 45 seconds) and expanded the channel to 2.12 mm (additional mean increase of 0.38 +/- 0.07 mm, p less than 0.001). In terms of percent luminal narrowing, laser radiation reduced obstruction from 80% to 45% (mean difference of -38.7 +/- 4.6%, p less than 0.001), and TCA caused a further decrease to 37% (mean difference of -9.3 +/- 1.9%, p less than 0.001). Thus, in tight atherosclerotic lesions, the laser may be useful in creating an initial opening enabling the placement of the balloon angioplasty catheter which, in turn, can further dilate the lased stenotic coronary lumen. PMID:2933943

  14. Branchen und Unternehmensbereiche

    NASA Astrophysics Data System (ADS)

    Kramer, Regine

    Dieses Kapitel gibt einen Überblick über die Haupteinsatzgebiete von Mathematikern, Informatikern, Naturwissenschaftlern und Ingenieuren in den wichtigsten Wirtschaftsbranchen und Unternehmensbereichen. Dabei werden ausbildungsnahe Aufgabenbereiche ebenso beschrieben wie eher fachferne Tätigkeiten und neben den klassischen Branchen und Berufsbildern auch neue Tätigkeitsfelder für MINT-Fachkräfte beschrieben.

  15. Spontaneous Coronary Dissection: "Live Flash" Optical Coherence Tomography Guided Angioplasty.

    PubMed

    Bento, Angela Pimenta; Fernandes, Renato Gil Dos Santos Pinto; Neves, David Cintra Henriques Silva; Patrício, Lino Manuel Ribeiro; de Aguiar, José Eduardo Chambel

    2016-01-01

    Optical Coherence tomography (OCT) is a light-based imaging modality which shows tremendous potential in the setting of coronary imaging. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndrome (ACS). The diagnosis of SCAD is made mainly with invasive coronary angiography, although adjunctive imaging modalities such as computed tomography angiography, IVUS, and OCT may increase the diagnostic yield. The authors describe a clinical case of a young woman admitted with the diagnosis of ACS. The ACS was caused by SCAD detected in the coronary angiography and the angioplasty was guided by OCT. OCT use in the setting of SCAD has been already described and the true innovation in this case was this unique use of OCT. The guidance of angioplasty with live and short images was very useful as it allowed clearly identifying the position of the guidewires at any given moment without the use of prohibitive amounts of contrast. PMID:26989520

  16. 'Transcollateral' Renal Angioplasty for a Completely Occluded Renal Artery

    SciTech Connect

    Chandra, Subash; Chadha, Davinder S. Swamy, Ajay

    2011-02-15

    Percutaneous transluminal renal angioplasty with stenting has been effective in the control of hypertension, renal function, and pulmonary edema caused by atherosclerotic renal artery stenosis. However, the role of the procedure has not been fully established in the context of chronic total occlusion of renal artery. We report the successful use of this procedure in 57-year-old male patient who reported for evaluation of a recent episode of accelerated hypertension. A renal angiogram in this patient showed ostial stenosis of the right renal artery, which was filling by way of the collateral artery. Renal angioplasty for chronic total occlusion of right renal artery was successfully performed in a retrograde fashion through a collateral artery, thereby leading to improvement of renal function and blood pressure control.

  17. Laser angioplasty of totally occluded arteries of the limb

    NASA Astrophysics Data System (ADS)

    Szopinski, Piotr; Hara, Marek; Noszczyk, Wojciech

    1996-03-01

    The authors summarize their experience in the use of Nd-YAG laser in chronic occlusion of lower limb arteries. Percutaneous transluminal laser angioplasty (PTLA) with laser-heated metal and sapphire tips were used as an adjuvant to conventional balloon angioplasty. In cases of reocclusions, endovascular stents were implanted. Laser recanalization was performed in 46 arteries (iliac, superficial femoral, and popliteal). Indications for the procedure were: limb salvage, claudication below 100 m, and temporal or rest pain. Initial clinical and hemodynamic improvement was observed in 37 (80%) patients. Four perforations occurred without clinical sequel. The one-year cumulative clinical patency was 27 (58%) of the 46 lesions. PTLA may be appropriate for high-risk patients, who are unsuitable for surgical reconstruction because of the concomitant diseases. The combination of laser recanalization and implantation of vascular stents may be a promising method in the management of limb ischemia.

  18. Spectroscopic feedback in laser lithotripsy and laser angioplasty

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; King, Terence A.; Shah, T.; Watson, Graham M.

    1992-08-01

    The feasibility of new forms of monitoring the fragmentation and ablation process through the plasma feedback signals in laser lithotripsy and laser angioplasty has been investigated. In laser lithotripsy it has been found that shock wave feedback monitoring is not as reliable as the plasma emission feedback monitoring. The plasma emission spectra indicate clearly plasma formation on calculi or calcified plaque, while an audible signal can be observed on targets such as dark tissue, catheter, and blood. This technique was successful in ex-vivo experiments in which calculi were inserted into pigs' ureter and then fragmented. Spectra were obtained in vivo indicating calcium abundance in calculi and the feasibility of real-time stone composition analysis. Ex-vivo gallstone fragmentation was also performed successfully under plasma spectra feedback monitoring. In laser angioplasty, in vitro experiments have shown a discriminative effect at laser pulse energies of 40 mJ or greater. Strong plasma spectra can only be observed from calcified plaque and not from normal artery tissue or fibrous plaque. The threshold for plasma formation on calcified plaque increases in blood compared to that in saline while the spectral structure becomes more specific. This study shows promising prospects for the technique in both laser lithotripsy and laser angioplasty.

  19. Transluminal coronary angioplasty in the treatment of silent ischemia

    SciTech Connect

    Bergin, P.; Myler, R.K.; Shaw, R.E.; Stertzer, S.H.; Clark, D.A.; Ryan, C.; Murphy, M.C.

    1988-01-01

    Fifty-four asymptomatic patients with positive thallium exercise tests underwent coronary angiography followed by coronary angioplasty (PTCA), as the primary therapy for silent ischemia. The procedure was technically successful in 89% of these patients. Emergency bypass graft surgery was necessary in 2 (3.6%) and q-wave myocardial infarction occurred in 1 (1.8%) of these. All fifty-four patients have been followed for a mean of 35 months since angioplasty. Of the 48 patients with initially successful PTCA, 12 had either clinical restenosis (9/14 or 19%) or a new lesion (3/48 or 6%) during follow-up, which required a repeat PTCA. At the longest follow-up, 46 (85%) had been successfully treated with on or more PTCA procedures. Two patients (3.6%) had sustained late q-wave myocardial infarction and two additional patients reported angina pectoris. There were no deaths. Angioplasty as a primary therapy for silent ischemia appears efficacious, with success and restenosis rates comparable to those in the symptomatic population. Event-free survival is improved, compared with natural history data for patients with silent ischemia from other studies. Prudent risk/benefit analysis may help to define subgroups most likely to benefit from this intervention.

  20. Effectiveness of the hugging balloon technique in coronary angioplasty for a heavy, encircling, calcified coronary lesion.

    PubMed

    Ahn, Min Soo; Yoon, Junghan; Lee, Jun Won; Lee, Kyoung Hoon; Kim, Jang Young; Yoo, Byung Su; Lee, Seung Hwan; Choe, Kyung Hoon

    2009-11-01

    We report our experience in coronary angioplasty and intravascular ultrasonography (IVUS) on a heavy, encircling, calcified lesion that was not dilated with the use of a cutting balloon and a non-compliant balloon. The angioplasty was successfully performed with a simple and inexpensive hugging balloon technique. PMID:19997547

  1. Arteriovenous fistula at the site of balloon dilatation complicating femoropopliteal angioplasty

    SciTech Connect

    Malcolm, Paul N.; King, David H.; Crabbe, Ray W.; Taylor, Peter R.; Reidy, John F.

    1997-01-15

    We describe an arteriovenous fistula (AVF) at the site of balloon dilatation immediately after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery. This occurred during an otherwise uncomplicated angioplasty with a good clinical result. The AVF closed spontaneously within 2 months as monitored by color duplex ultrasound. This uncommon complication of PTA is not widely recognized.

  2. Welt und Wirkungsprinzip

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    1997-05-01

    Modell einer kausalen Bewirkung der Welt, und logische, geometrische, physikalische Interprätation dieser Kausalmenge und Fortwirkung der frühsten ihrer sukzessiv als echt Neues bewirkten und durch Vorhandenes oder Späteres nicht darstellbaren oder widerrufbaren Ereignisse als Dimensionen und sie verkörpernde primäre Naturkräfte, mit Korrespondenz zur beobachteten Welt und ihrer grundlegendsten Eigenschaften. Wirklich ist nur was wirkt, wo und wie. Entsprechend ist im Bogenelement statt der Eigenzeit die variante Anzahl Wirkungen relevant, 0 ≈ 1/h2 dS2 - 1/tpl2 (dt2 - 1/c2 {dq12 + G02/G2 [dq2,32 - ...]}) mit G0 = c4lpl/Epl ≈ G. Die heutigen Dimensionen und Naturkräfte entstanden in dieser Reihenfolge, haben 'komplementäre' aber gleichwertige statische und dynamische Aspekte, entsprechend ihren Termen in Bogenelement bzw. Vierervektor, aus derem Vergleich sowie mit denen ihrer Nachbarn folgen Grundgleichungen bzw. Erhaltungssätze. Jeweils individuelle Eigenschaften wie ihre Naturkonstante konkretisieren sie und tragen zu gattungsmäßigen wie globale Affinität und Äquivalenzen bei. Ältestes Gebiet oder räumlicher Rand jeder Dimension sind die ersten vom Vorgänger bewirkten Ereignisse, selbst raumzeitlicher Ursprung des Nachfolgers, dort einmalig und ewig maximal rotverschoben fortwirkend und nicht lokalisierbar, um neue Elementareinheiten verschieden und lichtartig mit deren Verhältnis oder dem ihrer globalen Zustandsgrößen als konstanten Anfangsimpuls, Expansion, Längen- oder Ereignisdichte zueinander. Der Übergang vom diskreten Modell weniger Informationen zum Kontinuum und die Korrespondenz zur Physik ist problemlos, Details wie ein kontinuierlicher, abrupter oder ganz fehlender Abfall der Metrik beim ältesten Gebiet sind aber nur durch Beobachtungen entscheidbar. Erörtert werden allgemeine und individuelle Eigenschaften und ihre Konsequenzen der Dimensionen mit ihren Kräften, selbst und im Verhältnis zueinander, etwa ihrer begrenzten

  3. Primary Angioplasty for the Treatment of Acute ST-Segment Elevated Myocardial Infarction

    PubMed Central

    2004-01-01

    Executive Summary One of the longest running debates in cardiology is about the best reperfusion therapy for patients with evolving acute myocardial infarction (MI). Percutaneous transluminal coronary angioplasty (ANGIOPLASTY) is a surgical treatment to reopen a blocked coronary artery to restore blood flow. It is a type of percutaneous (through-the-skin) coronary intervention (PCI) also known as balloon angioplasty. When performed on patients with acute myocardial infarction, it is called primary angioplasty. Primary angioplasty is an alternative to thrombolysis, clot-dissolving drug therapy, for patients with acute MI associated with ST-segment elevation (STEMI), a change recorded with an electrocardiogram (ECG) during chest pain. This review of the clinical benefits and policy implications of primary angioplasty was requested by the Ontario Health Technology Advisory Committee and prompted by the recent publication of a randomized controlled trial (RCT) in the New England Journal of Medicine (1) that compared referred primary angioplasty with on-site thrombolysis. The Medical Advisory Secretariat reviewed the literature comparing primary angioplasty with thrombolysis and other therapies (pre-hospital thrombolysis and facilitated angioplasty, the latter approach consisting of thrombolysis followed by primary angioplasty irrespective of response to thrombolysis) for acute STEMI. There have been many RCTs and meta-analyses of these RCTs comparing primary angioplasty with thrombolysis and these were the subject of this analysis. Results showed a statistically significant reduction in mortality, reinfarction, and stroke for patients receiving primary angioplasty. Although the individual trials did not show significant improvements in mortality alone, they did show it for the outcomes of nonfatal reinfarction and stroke, and for an end point combining mortality, reinfarction, and stroke. However, researchers have raised concerns about these studies. A main concern

  4. Factors contributing to perforations resulting from laser coronary angioplasty: observations in an intact human postmortem preparation of intraoperative laser coronary angioplasty.

    PubMed

    Isner, J M; Donaldson, R F; Funai, J T; Deckelbaum, L I; Pandian, N G; Clarke, R H; Konstam, M A; Salem, D N; Bernstein, J S

    1985-09-01

    This investigation was designed to assess the potential use of laser coronary angioplasty as an intraoperative adjunct in the surgical treatment of ischemic heart disease. Among 17 postmortem hearts, simulated laser coronary angioplasty was performed at 53 sites with a No. 4F guiding catheter and 240 micron (200 micron core) quartz optical fiber. Perforation complicated laser coronary angioplasty in 33 (62%) of the 53 attempts. Most (n = 29) perforations were thermal; four were purely mechanical. Perforation sites were characterized by extensive calcific deposits (21 of 33 cases [64%] ) and the origin of a side branch (13 of 33 [39%] ). Excessive tortuosity of the extramural coronary artery contributed to arterial perforation in four cases, and precluded attempts to perform laser coronary angioplasty in two other cases. In 19 of the 53 attempts to perform laser coronary angioplasty, a high-frequency two-dimensional echocardiographic probe was used to image the coronary artery during antegrade manipulation of the optical fiber/guiding catheter and laser irradiation of the target arterial stenosis. Although perforation nevertheless occurred in 11 (58%) of 19 sites, only one mechanical perforation resulted; the remaining 10 were thermal. Characteristics of the perforation sites in this group were similar to those noted for the group as a whole. Experience with this model of laser coronary angioplasty indicates that even when access problems associated with percutaneous laser coronary angioplasty are obviated by a simulated intraoperative approach, perforation of the underlying coronary arterial wall continues to represent the "rate-limiting" complication of laser coronary angioplasty. Most perforations occurred in relation to calcific deposits, branch points, and tortuous coronary segments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3161660

  5. Physikunterricht und Kalter Krieg

    NASA Astrophysics Data System (ADS)

    Rieß, Falk; Kremer, Armin

    Die Indienstnahme des Physikunterrichts für militaristische und politische Zwecke ist in Deutschland nichts Neues: Die Wurzeln liegen im Kaiserreich und im Faschismus ("Wehrphysik"), und die Praxis im Kalten Krieg stellt hier nichts Außergewöhnliches, sondern lediglich eine auffällige Kontinuität dar.

  6. Modeling plaque fissuring and dissection during balloon angioplasty intervention.

    PubMed

    Gasser, T Christian; Holzapfel, Gerhard A

    2007-05-01

    Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage. PMID:17385047

  7. Early Results of Retrograde Transpopliteal Angioplasty of Iliofemoral Lesions

    SciTech Connect

    Saha, Saumitra; Gibson, Matthew; Magee, Timothy R.; Galland, Robert B.; Torrie, E. Peter H.

    2001-12-15

    Purpose: To assess whether the retrograde transpopliteal approach is a safe, practical and effective alternative to femoral puncture for percutaneous transluminal angioplasty (PTA).Methods: Forty PTAs in 38 patients were evaluated. Intentional subintimal recanalization was performed in 13 limbs. Ultrasound evaluation of the popliteal fossa was carried out 30 min and 24 hr post procedurally in the first 10 patients to exclude local complications. All patients had a follow-up of at least 6 weeks.Results: The indication for PTA was critical ischemia in seven limbs and disabling claudication in the remainder.Stenoses (single or multiple) were present in 24 and occlusion in 15.The superficial femoral artery (SFA) was the commonest segment affected(36) followed by common femoral artery (CFA) in four and iliac artery in four. Technical success was achieved in 38 of 39 limbs where angioplasty was carried out. In one limb no lesion was found.Immediate complications were distal embolization in two and thrombosis in one. None of these required immediate surgery. There were no puncture site hematomas or popliteal arteriovenous fistulae.Symptomatic patency at 6 weeks was 85%. Further reconstructive surgery was required in three limbs and amputation in two.Conclusion: The transpopliteal approach has a high technical success rate and a low complication rate with a potential to develop into an outpatient procedure. It should be considered for flush SFA occulsions or iliac disease with tandem CFA/SFA disease where the contralateral femoral approach is often technically difficult.

  8. Resistance to Clopidogrel among Iranian Patients Undergoing Angioplasty Intervention

    PubMed Central

    Haji Aghajani, Mohammad; Kobarfard, Farzad; Safi, Olia; Sheibani, Kourosh; Sistanizad, Mohammad

    2013-01-01

    To study the resistance to standard dosage of clopidogrel among Iranian patients following percutaneous coronary intervention measured by platelet aggregation test. Patients undergoing percutaneous coronary intervention in Imam Hussein Medical center, Tehran, Iran, who were under treatment with aspirin, but had no history of clopidogrel usage, entered the study. Patients received standard dosage of clopidogrel (Plavix®, Sanofi, France, 600 mg loading dose and 75 mg/day afterward). Platelet aggregation was measured using light transmission aggregometer. The response to the drug was categorized as complete resistance (platelet aggregation decreased less than 10%), intermediate resistance (platelet aggregation decreased between 10 to 30%) and complete response (platelet aggregation decreased to 30% or more). All patients were evaluated for major adverse cardio vascular events one month after the angioplasty based on MACE criteria by phone contact. Thirty-one patients with a mean age of 59 ± 13 entered the study. Sixty-five percent of patients showed complete response to clopidogrel (95% CI: 45% to 81%), 22% showed intermediate resistance (95% CI: 10-41%) and 13% showed complete resistance (95% CI: 4-30%). One month after the angioplasty, no major adverse cardiovascular event was recorded. Based on our findings, it seems that there is no major difference between Iranian population and other studies regarding the resistance to clopidogrel. Due to the limited number of participants in our study, further investigations with higher number of patients are recommended to more precisely calculate the percentage of resistance among Iranian patients. PMID:24250685

  9. Three years of clinical experiences on excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Viligiardi, Riccardo; Galiberti, Sandra; Pini, Roberto; Salimbeni, Renzo

    1992-03-01

    We report here the experience of our multidisciplinary group that has been working since 1986 on excimer laser angioplasty. After having selected the excimer laser between the available sources because of the negligible lesions left on the residual tissue, we had the purpose to develop a suitable laser and catheter system. Neglecting here all the preliminary studies, we outline only a typical phenomenon related to the energy delivery and useful for the comprehension of the recanalization process. The energy emitted by every single fiber determines, under a certain threshold, independent recanalized channels in the plaque with residual flaps. At a higher energy level the overposition of the lobes, due to the intrinsic divergence, up to the recanalization in a single large channel. In our opinion this condition is crucial in the design of the catheters to obtain an optical instead of a mechanical recanalization. The biological experimentation conducted during the preliminary tests on human hearts obtained from transplants or cadavers, convinced us that the correct goal to pursue was unique laser angioplasty without the need for further balloon dilation.

  10. Exploring expectations and needs of patients undergoing angioplasty.

    PubMed

    Aazami, Sanaz; Jaafarpour, Molouk; Mozafari, Mosayeb

    2016-09-01

    This study aimed to explore needs and expectations of Iranian patients who undergone angioplasty procedures. Coronary artery disease is the leading cause of morbidity and mortality worldwide. Recently, Percutaneous Coronary Intervention (PCI) has frequently been used as a substitute for coronary artery surgery, representing a less invasive and more cost-effective procedure. However, little information is known about the experiences and needs of patients undergone PCI. This research involved a qualitative study that employed the content analysis method. A semi-structured in-depth interview protocol was carried out using a face-to-face approach. Researchers reached to theoretical saturation by interviewing 18 patients who undergone angioplasty. Constant comparison analysis was used with simultaneous data collection. Three themes emerged from this study including Uncertainty, Procedural knowledge and Social Support. The findings from this study enhance our understanding on expectations and needs of patients who undergone PCI. These findings help nurses and health-care providers to develop and provide pre and post-procedural care according to each individual needs and experiences. This Iranian study not only contributes to other international study but also, emphasizes on the need for pre-procedural awareness and post-procedural support of patients who undergone PCI. PMID:27568316

  11. The Role of Coagulation and Inflammation After Angioplasty in Patients with Peripheral Arterial Disease

    SciTech Connect

    Wahlgren, C.M. Sten-Linder, M.; Egberg, N.; Kalin, B.; Blohme, L.; Swedenborg, J.

    2006-08-15

    Purpose. Restenosis remains a frequent complication after angioplasty in peripheral arterial disease. Inflammation plays a critical role in the vascular response to injury. Effective medical treatment to improve patency after angioplasty is still elusive. The aims of this prospective clinical study were to investigate changes in blood coagulation and inflammatory markers after angioplasty and their significance for restenosis. Methods. Thirty-four patients with peripheral arterial disease underwent angioplasty of the iliac and superficial femoral arteries. Ten patients undergoing diagnostic angiography were included in the study as controls. Plasma levels of tissue factor, prothrombin fragment 1 + 2, D-dimer, P-selectin, C-reactive protein (CRP), and fibrinogen were analyzed before and after angioplasty. Patients were followed up with angiography after 6 months to assess restenosis. Results. CRP was elevated the day after angioplasty (6.6 mg/l, p = 0.0001) and tended to peak after 1 week (11 mg/l, p = 0.09). There was a significant increase of D-dimer and P-selectin 1-4 hr after angioplasty (0.4 mg/l, p = 0.001 and 68 ng/ml, p = 0.05, respectively). None of the biochemical markers was a statistically significant predictor of restenosis. Conclusion. We have observed a much more prolonged inflammatory response than previously noted, but only minor changes in coagulation activity after angioplasty. The biochemical markers, before and after angioplasty, were not related to restenosis. Further studies are needed to delineate the molecular mechanisms behind these observations and their involvement in thrombosis and restenosis. If these pathways are further defined, improved treatment strategies, including antithrombotic treatments and statins, could be tailored to modulate postprocedural inflammation.

  12. Digital coronary roadmapping as an aid for performing coronary angioplasty.

    PubMed

    Tobis, J; Johnston, W D; Montelli, S; Henderson, E; Roeck, W; Bauer, B; Nalcioglu, O; Henry, W

    1985-08-01

    In an attempt to improve visualization of the position of the guidewire and dilatation balloon during coronary angioplasty, a method was developed called digital coronary roadmapping. With this method a digitally acquired coronary angiogram is interlaced with the live fluoroscopic image of the guidewire and balloon catheter. The digital coronary angiogram is superimposed at the same magnification and radiologic projection as the live fluoroscopic image onto the video monitor above the catheterization table. The digital roadmap image thus provides immediate feedback to the angiographer to assist in directing the guidewire into the appropriate coronary artery branch and to help in placement of the balloon so that it straddles the site of stenosis. PMID:3161319

  13. More accurate assessment of stenotic lesions in percutaneous transluminal angioplasty.

    PubMed

    Janevski, B K; Breslau, P J; Jorning, P J

    1986-01-01

    Eighty patients underwent percutaneous transluminal dilatation and recanalisation of atheromatous lesions of the arteries of the lower extremities in the University Hospital of Maastricht in the period of 1980 to 1984. Out of 80 attempted procedures of the iliac and femoro-popliteal tract 71 (89%) were technically possible and were considered initially successful. In all cases of iliac artery lesions a retrograde arteriogram was performed prior to PTA. Intra-arterial pressure measurements at rest and after hyperemia were used for exact assessment of the hemodynamic significance of the stenosis before and after PTA. A follow-up of all patients successfully treated by angioplasty was performed. The early hemodynamic success rate of PTA for iliac lesions was 90 per cent and for femoral-popliteal segment 83 per cent. There was no morbidity or mortality. The cumulative 3-year patency rate for both segments was 74 per cent. PMID:2943842

  14. Geoinformation und Staat

    NASA Astrophysics Data System (ADS)

    Zypries, Brigitte

    2002-09-01

    Geoinformationen besaßen als Grundlage militärischer Interventionen schon immer einen hohen Stellenwert für den Staat. Im Zeitalter der modernen Informations- und Kommunikationstechnologien wächst in demokratischen Staaten die Bedeutung von Geodaten weit über den Verteidigungsbereich hinaus. Brigitte Zypries, Staatssekretärin im Bundesministerium des Innern (BMI) und Vorsitzende des Interministeriellen Ausschusses für Geoinformationswesen (IMAGI), sprach mit Dipl.-Geogr. Ute C. Bauerüber die Anwendung und Koordinierung von Geodaten in Politik und Staat.

  15. Integument und Anhangsorgane

    NASA Astrophysics Data System (ADS)

    Schliemann, Harald

    Das Integument umhüllt den Wirbeltierkörper lückenlos. In der embryonalen Mundbucht (Stomodaeum) und der Afterbucht (Proctodaeum) grenzt es an die Auskleidung des Darmrohres. Über die generelle Bedeutung einer Haut als Abgrenzung zwischen Körperinnenraum und Außenmedium hinaus hat es bei Schädeltieren ein breites Spektrum von Funktionen. Die wichtigsten sind: Mechanischer Schutz durch Verhornungen und Verknöch erungen; Wundheilung; Schutz vor Wasserverlust; Schutz vor Infektionen durch bakterizide Drüsensekrete und immunkompetente Zellen; Schutz vor kurzwelliger Strahlung durch Pigmente; Schutz vor Überwärmung durch Schweißdrüsensekrete und Schutz vor Wärmeverlust durch Federn und Haare; Ausbildung lokomotorisch wichtiger Strukturen wie Federn, Flug- und Schwimmhäute, Krallen und Hufe; Redukt ion des Strömungswiderstandes durch Dämpfungshaut; Abgabe von Sekreten zur Ernährung (Milch); Ausbildung von Strukturen zu Nahrungserwerb und_-bearbeitung, z. B. Zähne, Barten;

  16. Sternbilder und ihre Mythen

    NASA Astrophysics Data System (ADS)

    Fasching, Gerhard

    Die Sternbilder, die seit alters her die Menschen in ihren Bann gezogen haben, und die damit verbundenen Mythen werden in zweifacher Weise vorgestellt. Erstens ist es die Absicht, dem Leser zu helfen, sich am Sternenhimmel zurechtzufinden, und zweitens will es ihm die Vielfalt der Bilder vermitteln, die damit verbunden sind. Am Anfang des Buches stehen die prächtigen Erzählungen aus Ovids Metamorphosen. Dann ist vom Sternenhimmel im Jahreskreis die Rede, um den Leser anzuregen, diesen fast unendlichen Bilderreichtum sich selbst durch eigene Beobachtungen zu erschließen. Ein umfangreicher Abschnitt behandelt die einzelnen Sternbilder und das hierzu überlieferte Wissen. Sternkarten und alte Kupferstiche aus dem Bestand der Österreichischen Nationalbibliothek zeigen, wie man sich in früheren Jahrhunderten den Sternenhimmel vorgestellt hat. Sternsagen und Mythen werden erzählt und auch das ptolemäische und das kopernikanische Weltsystem werden einander gegenübergestellt. Ausführliche Sachverzeichnisse mit über 3000 Suchbegriffen erleichtern den Zugang zu Stern- und Sternbildnamen und zur Mythologie.

  17. Roboter und Zuckerstangen

    NASA Astrophysics Data System (ADS)

    Siebert, Heike

    Bei Produktion und Logistik denkt man sofort an Fabriken, Lagerhallen und Gabelstapler und nicht unbedingt an Zellbiologie. Sieht man etwas genauer hin erscheint dieser Gedankensprung jedoch gar nicht mehr so unpassend. In einer lebenden Zelle laufen eine Vielzahl von Produktions-, Transport- und Regulationsprozessen ab. Soll etwa ein gerade verfügbarer Rohstoff abgebaut werden, muss vielleicht ein Signal ein Gen erreichen, das ein geeignetes Enzym kodiert. Die Aktivierung des Gens führt über mehrere Zwischenstationen zur Produktion des Enzyms, das schließlich noch dahin gelangen muss, wo es gebraucht wird. Ist der Bedarf gedeckt, muss wiederum die Enzymproduktion eingestellt werden.

  18. Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction

    PubMed Central

    Suryapranata, H; Ottervanger, J; Nibbering, E; van't, H; Hoorntje, J; de Boer, M J; Al, M; Zijlstra, F

    2001-01-01

    OBJECTIVE—To investigate the long term clinical outcome and cost-effectiveness of stenting compared with balloon angioplasty in patients with acute myocardial infarction.
METHODS—Patients with acute myocardial infarction were randomly allocated to primary stenting (112) or balloon angioplasty (115). The primary end point was the cumulative first event rate of death, non-fatal reinfarction, or target vessel revascularisation. Secondary end points were restenosis at six months and the cost-effectiveness at follow up.
RESULTS—After 24 months, the combined clinical end point of death/reinfarction was 4% after stenting and 11% after balloon angioplasty (p = 0.04). Subsequent target vessel revascularisation was necessary in 15 patients (13%) after stenting and in 39 (34%) after balloon angioplasty (p < 0.001). The cumulative cardiac event-free survival rate was also higher after stenting (84% v 62%, p < 0.001). The angiographic restenosis rate after stenting was less than after balloon angioplasty (12% v 34%, p < 0.001). Despite the higher initial costs of stenting (Dfl 21 484 v Dfl 18 625, p < 0.001), the cumulative costs at 24 months were comparable with those of balloon angioplasty (Dfl 31 423 v Dfl 32 933, p = 0.83).
CONCLUSIONS—Compared with balloon angioplasty, primary stenting for acute myocardial infarction results in a better long term clinical outcome without increased cost.


Keywords: stenting; angioplasty; myocardial infarction; cost-benefit analysis PMID:11359749

  19. Results of coronary surgery after failed elective coronary angioplasty in patients with prior coronary surgery.

    PubMed

    Weintraub, W S; Cohen, C L; Curling, P E; Jones, E L; Craver, J M; Guyton, R; King, S B; Douglas, J S

    1990-11-01

    The results of coronary artery bypass surgery after failed elective coronary angioplasty in patients who have undergone prior coronary surgery are unknown. Coronary angioplasty may be performed to relieve angina after surgery either to the native coronary vessels or to grafts. Failure of attempted coronary angioplasty may mandate repeat coronary surgery, often in the setting of acute ischemia. From 1980 to 1989, 1,263 patients with prior coronary bypass surgery underwent angioplasty; of these patients, 46 (3.6%) underwent reoperation for failed angioplasty during the same hospital stay. Of the 46 patients who underwent reoperation, 33 had and 13 did not have acute ischemia. In the group with ischemia, 3 patients (9.1%) died and 14 (42.4%) died or had a Q wave myocardial infarction in the hospital compared with no deaths (p = NS) and no deaths or Q wave myocardial infarction (p = 0.005) in the group without ischemia. At 3 years, the actuarial survival rate was 88 +/- 6% in the group with ischemia, whereas there were no deaths in the group without ischemia (p = NS), and freedom from death or myocardial infarction was 51 +/- 10% in the group with ischemia, versus no events in the group without ischemia (p = 0.006). In most patients with prior coronary bypass surgery, coronary angioplasty was performed without the need for repeat coronary bypass surgery. Should coronary angioplasty fail, reoperation in patients without acute ischemia can be performed with overall patient survival comparable to that of elective reoperative coronary bypass without coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2229784

  20. Nd:YAG iliac and femoropopliteal laser angioplasty: results with large probes as "sole therapy".

    PubMed

    Rosenthal, D; Wheeler, W G; Seagraves, A; Erdoes, L; Lamis, P A; Jones, M; Clark, M D; Pallos, L L

    1991-01-01

    Laser assisted balloon angioplasty with a laser heated metallic capped fiberoptic catheter may be effective in the treatment of femoral and iliac artery occlusive disease. In order to avoid the inherent trauma of balloon angioplasty, yet at the same time "debulk" atheroma, 75 patients underwent laser angioplasty of the superficial femoral and iliac arteries as "sole therapy". Laser angioplasty was performed using an Nd:YAG laser coupled to a 600 micron fiber and a 3.5 mm probe (22-28 watts), 4.2 mm or 5.0 probe (32-40 watts). Fifty-nine patients had laser angioplasty for claudication and 16 for limb salvage. The initial angiographic success rate was 84% (41/49) (lesion length 2-14 cm) for the superficial femoral and 69% (18/26) (lesion length 2-14 cm) for the iliac arteries. In follow-up extending to 21 months (mean 14.4 months) 73% (30/41) of the superficial femoral artery and 76% (14/18) of the initially recanalized iliac arteries remain patent. When initial failures are included, this represents an overall intermediate-term patency rate of 52% (32/49) for superficial femoral and 49% (14/26) for iliac arteries respectively. By avoiding the disruptive effect on the arterial wall architecture caused by balloon angioplasty, while at the same time ablating and vaporizing more atheromatous material with larger laser probes, the long-term patency rates of laser angioplasty as "sole therapy" may prove to be superior to those of laser assisted balloon angioplasty. PMID:2019619

  1. Overview Of Angioplasty: Need For Imaging And Sensing

    NASA Astrophysics Data System (ADS)

    Borst, Cornelius; Rienks, Rienk; Verdaasdonk, Rudolph M.

    1989-08-01

    Balloon angioplasty is a well established non-surgical treatment of ischemic vascular disease. Balloon dilatation increases the lumen in a stenosed artery by overstretching the wall and fracturing the atherosclerotic plaque. Fluoroscopy is adequate to guide the proper placement of guide wire and balloon catheter. Fluoroscopy largely fails, however, when a different recanalization strategy is choosen to address the major problems associated with balloon dilatation. In the past few years, more than twenty different recanalization catheters have been developed that physically remove obstructing plaque. In the femoral artery, both mechanical and thermal methods appear to be quite successful in traversing total occlusions in spite of 'blind' guidance by fluoroscopy. However, subsequent balloon dilatation is often needed. The femoral artery is large and runs a fairly straight course. Perforation of the femoral artery is a minor complication. In the coronary arteries, in contrast, the novel angioplasty methods have met with variable success. These arteries are small, tortuous and move continuously. The anatomy and composition of the plaque is complex and the remainder of the diseased wall may be thin. In the coronary arteries, the margin between recanalization and perforation is small. The latter is a potentially fatal complication. Thus, there is a great need for a catheter that is capable of high resolution imaging and tissue identification in obstructed arteries of small caliber. Intra-arterial echo imaging, possibly combined with laser fluorescence spectroscopy, seems a promising approach. The design of a catheter that combines these powerful diagnostic features with steerability, flexibility and controlled ablation is now the major engineering challenge in interventional cardiology.

  2. Endovascular Stenting for Unsuccessful Angioplasty of the Aorta in Aortoarteritis

    SciTech Connect

    Tyagi, Sanjay; Kaul, Upkar A.; Arora, Ramesh

    1999-11-15

    Purpose: The efficacy and safety of endovascular stent implantation to correct dissection or a suboptimal result after percutaneous transluminal angioplasty (PTA) was evaluated in patients suffering from aortic stenosis due to aortoarteritis. Methods: Twelve children and young adults [aged (mean {+-} SD) 18.2 {+-} 8.7 years] underwent stent implantation after PTA of the aorta, seven for obstructive dissection, four for ineffective balloon dilatation, and one for recurrent restenosis. Nine patients underwent implantation of self-expandable stents and three received balloon-expandable Palmaz stents. Results: Stent implantation could be successfully performed in all 12 patients. After stent implantation, the peak systolic pressure gradient decreased from 91 {+-} 33.5 mmHg to 12.4 {+-} 12.5 mmHg (p < 0.001). The diameter of the stenosed segment increased from 4.6 {+-} 0.8 mm to 11.1 {+-} 1.9 mm (p < 0.001). The dissection was completely covered in all seven patients with dissection. Except for epigastric pain with vomiting in one patient, there was no complication. On follow-up, over 12-57 months (mean 26.8 {+-} 10.8 months), 11 patients (91.6%) had marked improvement in their blood pressure. Patients with congestive heart failure and claudication also showed improvement. Repeat catheterization in five patients, between 6-30 months (mean 16.8 {+-} 9.1 months) after stent implantation, showed sustained improvement in four and a fusiform, long segment, intrastent restenosis after 30 months in one child. The stenosis was safely redilated. Conclusion: Endovascular aortic stent implantation is safe and provides good immediate relief in patients with unsatisfactory results after balloon angioplasty. Improvement is sustained in most patients on intermediate-term follow-up.

  3. Subintimal Angioplasty for Peripheral Arterial Occlusive Disease: A Systematic Review

    SciTech Connect

    Met, Rosemarie Lienden, Krijn P. Van; Koelemay, Mark J. W.; Bipat, Shandra; Legemate, Dink A.; Reekers, Jim A.

    2008-07-15

    The objective of this study was to summarize outcomes of subintimal angioplasty (SA) for peripheral arterial occlusive disease. The Cochrane Library, Medline and Embase databases were searched to perform a systematic review of the literature from 1966 through May 2007 on outcomes of SA for peripheral arterial occlusive disease of the infrainguinal vessels. The keywords 'percutaneous intentional extraluminal revascularization,' 'subintimal angioplasty,' 'peripheral arterial disease,' 'femoral artery,' 'popliteal artery,' and 'tibial artery' were used. Assessment of study quality was done using a form based on a checklist of the Dutch Cochrane Centre. The recorded outcomes were technical and clinical success, primary (assisted) patency, limb salvage, complications, and survival, in relation to the clinical grade of disease (intermittent claudication or critical limb ischemia [CLI] or mixed) and location of lesion (femoropopliteal, crural, or mixed). Twenty-three cohort studies including a total of 1549 patients (range, 27 to 148) were included in this review. Methodological and reporting quality were moderate, e.g., there was selection bias and reporting was not done according to the reporting standards. These and significant clinical heterogeneity obstructed a meta-analysis. Reports about length of the lesion and TASC classification were too various to summarize or were not mentioned at all. The technical success rates varied between 80% and 90%, with lower rates for crural lesions compared with femoral lesions. Complication rates ranged between 8% and 17% and most complications were minor. After 1 year, clinical success was between 50% and 70%, primary patency was around 50% and limb salvage varied from 80% to 90%. In conclusion, taking into account the methodological shortcomings of the included studies, SA can play an important role in the treatment of peripheral arterial disease, especially in the case of critical limb ischemia. Despite the moderate patency

  4. Balloon valvuloplasty and angioplasty in congenital heart disease.

    PubMed Central

    Miller, G A

    1985-01-01

    Balloon dilatation valvuloplasty was performed in 16 patients with pulmonary valve stenosis aged 10 days to 17 years. Gradients were reduced in all but two patients and were less than or equal to 20 mm Hg after the procedure in all but these two and one other. Unsatisfactory initial results in these three patients were attributed to the use of too small a balloon in one patient (gradient subsequently abolished at repeat valvuloplasty), to a dysplastic valve in a neonate, and to the fact that there had been a previous surgical valvotomy with scar tissue formation in one patient. The good result was retained in six of seven patients followed up at three to six months. In one the gradient, having been reduced from 60 to 18 mm Hg, had risen to 35 mm Hg. Repeat valvuloplasty was technically impossible in this patient, but in two others residual gradients of 24 and 22 mm Hg were reduced to 4 and 8 mm Hg respectively by repeat valvuloplasty. Balloon dilatation angioplasty was successful in dilating a severe stenosis at the lower limb of an atrial baffle (previous correction of complete transposition) and in dilating supravalvar stenosis of the pulmonary artery resulting from previous banding and debanding. Thus balloon pulmonary valvuloplasty, though still a new technique, appears to be the treatment of choice in patients with typical pulmonary stenosis and thin mobile valves. Patients with dysplastic valves may be less suitable candidates for the procedure. Balloon angioplasty is likely to have other applications, including the treatment of postoperative stenotic lesions. Images PMID:2931093

  5. Angioplasty or Primary Stenting for Infrapopliteal Lesions: Results of a Prospective Randomized Trial

    SciTech Connect

    Randon, C. Jacobs, B.; De Ryck, F.; Vermassen, F.

    2010-04-15

    Excellent results with small stents in coronary arteries have led endovascular therapists to their use in infrapopliteal vessels. However, to date no level I evidence exists to recommend primary stenting over infrapopliteal angioplasty alone. The aim of this randomized single-center trial was to compare their 1-year outcome. A total of 38 limbs in 35 patients with critical limb ischemia were randomized to angioplasty (22 pts) or primary stenting (16 pts). Target lesions were infrapopliteal occluded (36) or stenotic (20) lesions ranging from <2 to >15 cm in length. The mean age was 72 years. At 12 months, there was no statistical difference in survival (angioplasty, 69.3%; primary stenting, 74.7%), in limb salvage (angioplasty, 90%; primary stenting, 91.7%), or in primary and secondary patency (angioplasty, 66 and 79.5%; primary stenting, 56 and 64%) between the groups Renal insufficiency was the only significant negative predicting factor for limb salvage in both groups. In conclusion, the 1-year results for both groups were broadly similar. Stenting has its place in infrapopliteal angioplasty if the procedure is jeopardized by a dissection or recoil, but our results do not support primary stenting in all cases.

  6. [Role of laser angioplasty in the management of peripheral arteriopathies. Report of 79 cases].

    PubMed

    Henry, M; Beron, R; Chastel, A; Voiriot, P

    1990-01-01

    From May 1988 to November 1989, 79 of the 341 patients admitted to our center requiring angioplasty for peripheral artery disease were treated by laser angioplasty (LA) associated with secondary dilatation. Laser angioplasty was performed with and Nd-YAG laser coupled by an optical fiber to 1.8, 2.2 and 3 mm sapphires. The population studied included 64 men and 15 women (mean age: 66 years). Functional outcome before LA was class II in 85% of cases (n = 67) and class III and IV respectively in 10 (13%) and 2 patients. Laser angioplasty was the primary indication in 61 patients (77%) with a femoropopliteal (n = 53), iliac (n = 7) or axillary (n = 1) arterial obstruction. Laser angioplasty was the secondary indication in stenoses which could not be negotiated by a guide or balloon (23%; n = 18). Laser angioplasty led to repermeabilization of arterial occlusions in 82% of cases. The best results were obtained for short occlusions of less than 3 cm (n = 5; 100%) and for femoropopliteal lesions (n = 60; 85%). Stenoses were revascularized in all cases. Complementary dilatation was performed at the same time in all revascularized patients. Forty-seven revascularized patients were followed up 3 to 6 months after LA. Results were good in 36 cases (77%); restenosis occurred in 7 cases (15%); and reocclusion in 4 cases (8%). It was possible to treat all restenoses percutaneously (dilatation: n = 5; extruder: n = 1; stent: n = 1).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2286812

  7. Clinical significance of perfusion defects by thallium-201 single photon emission tomography following oral dipyridamole early after coronary angioplasty

    SciTech Connect

    Jain, A.; Mahmarian, J.J.; Borges-Neto, S.; Johnston, D.L.; Cashion, W.R.; Lewis, J.M.; Raizner, A.E.; Verani, M.S.

    1988-05-01

    The clinical significance of myocardial perfusion defects present early after angiographically successful percutaneous transluminal coronary angioplasty was assessed in 53 patients using thallium-201 single photon emission computed tomography combined with pharmacologic vasodilation induced by a large dose (300 mg) of orally administered dipyridamole. Myocardial tomographic images were obtained at a mean of 20 +/- 6 h (SD) before and 2.9 +/- 2.7 days after angioplasty. Before angioplasty, 15 (28%) of the 53 patients developed angina after dipyridamole administration, in contrast to only 3 (7.5%) of 40 patients after angioplasty (p less than 0.001). The mean percent luminal area stenosis decreased from 93 +/- 6% before angioplasty to 34 +/- 17% after angioplasty (p less than 0.001). Myocardial perfusion defects, present in 49 (93%) of the 53 patients before angioplasty, were reversible in 44 patients (83%), all of whom underwent dilation of arteries supplying the ischemic areas. After angioplasty, 26 (65%) of 40 patients had no ischemic defects, whereas 14 (35%) of the patients still had an ischemic defect in the vascular territory of the dilated artery. After a mean follow-up period of 21.7 months, 13 (33%) of 39 patients developed restenosis, 10 of whom had an ischemic defect early after angioplasty. Restenosis developed in 10 (71%) of 14 patients with an ischemic defect after angioplasty, but in only 3 (11.5%) of the patients without an ischemic defect (p = 0.007). In conclusion, thallium-201 tomography after oral dipyridamole affords convenient assessment of the physiologic significance of coronary stenosis present before angioplasty and the residual stenosis after angioplasty.

  8. Katzenaugen und Sternsteine: Spielwiese

    NASA Astrophysics Data System (ADS)

    Ucke, Christian; Schlichting, Hans-Joachim

    2004-07-01

    Edelsteine vom Typ Chrysoberyll sind auch unter der Kurzbezeichnung Katzenauge bekannt. Im Chrysoberyll eingelagert sind feine, parallel angeordnete, metallisch glänzende Nadeln aus Rutil (Titandioxid). Auch Hohlkanäle und Risse durchziehen das Material. Lichtreflexion an diesen Einlagerungen und Kanälen erklärt das Lichtband, das dem Stein zu seinem Namen verhalf.

  9. Falten und fliegen: Papierflieger und ihre Physik

    NASA Astrophysics Data System (ADS)

    Gruber, Werner

    2004-09-01

    Mit Papierfliegern können wichtige Eigenschaften der Aerodynamik anschaulich vermittelt werden: ein Blatt Papier, ein paar Faltungen und schon kann man experimentieren. Allerdings sind beim Trimmen des Fliegers einige Punkte zu beachten. Besonders wichtig ist die Y-Stellung der Flügel, die ihm Flugstabilität verleiht. Ist der Flieger fertig, dann gilt es, die dem Modell am besten angepasste Wurftechnik herauszufinden. Dazu variiert man Wurfgeschwindigkeit und Abwurfwinkel. Den Boden kann ein Papierflieger auf vier prinzipiell verschiedenen Flugkurven erreichen: Optimal ist die Gerade, dann fliegt er am weitesten.

  10. Use of Reactor-Produced Radioisotopes for Prevention Restenosis After Angioplasty

    SciTech Connect

    Knapp, F.F.; Pipes, D.W.

    1999-12-21

    Coronary heart disease leads to myocardial infarction and is a major cause of death in the US. Myocardial infarctions result from atherosclerotic plaque deposits in the coronary arteries, reducing blood flow through these arteries which supply oxygen and nutrients to the heart muscle. The two major approaches for restoring adequate blood flow are coronary bypass graft surgery and coronary angioplasty. Angioplasty is a routinely used clinical procedure, where a deflated balloon attached to the end of a long catheter is inserted into an artery in the leg and then advanced through the aorta into the blocked regions of the coronary arteries. After positioning in the occluded region of the artery, the balloon is inflated with a pressurized saline solution which opens the artery restoring blood flow by pressing the atherosclerotic plaque into the vessel wall. Angioplasty is a widely performed procedure with the coronary arteries and is a much less expensive alternative to coronary bypass surgery. The best patients for angioplasty are those with single occlusions and this method is preferred over bypass grafting because of the significantly reduced expense. The reformation of plaque deposits in arteries (restenosis) following angioplasty, however, is a major clinical problem encountered in as high as 40 percent of patients. Because reduction of health care costs is a major national priority, development of effective new preventative methods for restenoses is an important national priority.

  11. A Model of Primary Atherosclerosis and Post-Angioplasty Restenosis in Mice

    PubMed Central

    Leidenfrost, Jeremy E.; Khan, M. Faisal; Boc, Kenneth P.; Villa, Brian R.; Collins, Emily T.; Parks, William C.; Abendschein, Dana R.; Choi, Eric T.

    2003-01-01

    Although mice deficient in various genes are providing greater insight into the mechanisms of restenosis after angioplasty, there have been limitations with murine models not simulating human vascular disease. To develop a more clinically applicable model of primary atherosclerosis and restenosis following angioplasty of the primary lesion, we fed apolipoprotein E-deficient mice a Western diet and occluded the left common carotid artery for 2 days. Three weeks after flow was restored, the temporarily occluded carotids demonstrated atherosclerotic lesions containing foam cells, cholesterol clefts, necrotic cores, and fibrous capsules. The atherosclerotic carotids in other animals underwent angioplasty with a beaded probe, resulting in plaque and medial layer disruption. Three weeks after angioplasty, although there was significant neointimal lesion formation, the luminal narrowing did not change significantly secondary to overall vessel enlargement (positive remodeling). Neointimal lesions were composed of smooth-muscle cells and extracellular matrix observed adjacent to the original atherosclerotic plaques. Similarly, even at 3 months after the angioplasty the lumen was maintained despite greater neointimal lesion formation caused by progressive positive remodeling. This new murine model of primary atherosclerosis and postangioplasty intimal hyperplasia and remodeling mimics the human disease pattern of postangioplasty intimal hyperplasia. Used in transgenic animals, this model will likely facilitate understanding of the mechanisms of restenosis in humans. PMID:12875996

  12. Clinical Outcomes of Infrapopliteal Angioplasty in Patients With Critical Limb Ischemia

    PubMed Central

    Ryu, Hyeon Min; Kim, Jung-Sun; Ko, Young Guk; Hong, Myeong-Ki; Jang, Yangsoo

    2012-01-01

    Background and Objectives With recent advances in equipment and techniques, infrapopliteal angioplasty has shown results that are comparable to those of surgical bypass in patients with critical limb ischemia (CLI). In this study, we evaluated the efficacy and the feasibility of infrapopliteal angioplasty in patients with CLI. Subjects and Methods Between March 2002 and May 2008, infrapopliteal angioplasty was performed on 118 limbs of 101 patients (79 males; mean age 66 years) with CLI (Rutherford category 4, 5 or 6). Freedom from reintervention, limb salvage, and overall survival were analyzed. Results The median follow-up duration was 30 months. Initial technical and clinical success rates were 69.5% and 83.1%, respectively. No major complication requiring surgical intervention developed after angioplasty. Among 82 limbs with initial technical success, the rate of freedom from any reintervention at 2 years was 70.7% and that from limb salvage was 97.6%. Young age and Rutherford category 6 at initial presentation were independent predictors associated with poor 2 year primary patency in these patients with CLI. Overall survival at 1 year was 86.4% and that at 2 years 76.3%. A history of cerebrovascular accident was an independent predictor associated with poor 2 year survival in these patients. Conclusion Infrapopliteal angioplasty as a primary choice of treatment in CLI patients showed favorable clinical outcomes and feasibility. PMID:22563339

  13. Messung und Analyse

    NASA Astrophysics Data System (ADS)

    Bathelt, Hartmut; Scheinhardt, Michael; Sell, Hendrik; Sottek, Roland; Guidati, Sandro; Helfer, Martin

    Für die Beurteilung von Akustik und Fahrkomfort eines Fahrzeugs gilt in der Fahrzeugentwicklung immer noch der alte Grundsatz: "Der Kunde fährt nicht am Prüfstand, sondern auf der Straße“. Daher werden Gesamtbeurteilungen des Entwicklungsstandes und Konkurrenzvergleiche (Benchmarking) nach wie vor auf der Straße durchgeführt, meist auf ausgewählten Fahrbahnen am Prüfgelände oder im Rahmen der regelmäßigen Winter- und Sommererprobungen unter extremen Witterungsverhältnissen.

  14. Holmium:YAG laser angioplasty: treatment of acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On

    1993-06-01

    We report our clinical experience with a group of 14 patients who presented with acute myocardial infarction. A holmium:YAG laser was applied to the infarct-related artery. This laser emits 250 - 600 mJ per pulse, with a pulse length of 250 microseconds and repetition rate of 5 Hz. Potential benefits of acute thrombolysis by lasers include the absence of systemic lytic state; a shortened thrombus clearing time relative to using thrombolytics; safe removal of the intracoronary thrombus and facilitation of adjunct balloon angioplasty. Potential clinical difficulties include targeting the obstructive clot and plaque, creation of debris and distal emboli and laser-tissue damage. It is conceivable that holmium:YAG laser can be a successful thrombolytic device as its wave length (2.1 microns) coincides with strong water absorption peaks. Since it is common to find an atherosclerotic plaque located under or distal to the thrombotic occlusion, this laser can also be applied for plaque ablation, and the patient presenting with acute myocardial infarction can clearly benefit from the combined function of this laser system.

  15. Tool/tissues interaction modeling for transluminal angioplasty simulation.

    PubMed

    Le Fol, T; Haigron, P; Lucas, A

    2007-01-01

    In this paper, a simulation environment is described for balloon dilation during percutaneous transluminal angioplasty. It means simulating tool/tissues interactions involved in the inflation of a balloon by considering patient specific data. In this context, three main behaviors have been identified: soft tissues, crush completely under the effect of the balloon, calcified plaques, do not admit any deformation but could move in deformable structures and blood vessel wall and organs, try to find their original forms. A deformable soft tissue model is proposed, based on the Enhanced ChainMail method to take into account tissues deformation during dilatation. We improved the original ChainMail method with a "forbidden zone" step to facilitate tool/tissues interactions. The simulation was implemented using five key steps: 1) initialization of balloon parameters; 2) definition of the data structure; 3) dilatation of the balloon and displacement approximation; 4) final position estimation by an elastic relaxation; and 5) interpolation step for visualization. Preliminary results obtained from patient CT data are reported. PMID:18002311

  16. Successful Percutaneous Transluminal Angioplasty and Stenting in Acute Mesenteric Ischemia

    SciTech Connect

    Gartenschlaeger, Soeren Bender, Siegfried; Maeurer, Juergen; Schroeder, Ralf J.

    2008-03-15

    Acute mesenteric ischemia (AMI) is a life-threatening emergency. The complications are high by the time of diagnosis in most cases and therefore only few data on primary percutaneous intervention with percutaneous transluminal angioplasty (PTA) and stenting in AMI are available. We present the case of an 84-year-old woman who presented to our emergency department complaining of an acute worsening of pre-existing abdominal periumbilical pain, nausea, vomiting, and diarrhea. She had previously undergone percutaneous transluminal embolectomy for an acute occlusion of the left common femoral artery. Due to suspicion of intestinal infarction, conventional angiography of the aorta and the superior mesenteric artery (SMA) was performed and confirmed a proximal occlusion of the SMA. Percutaneous SMA recanalization with balloon dilation and subsequent stent implantation was carried out successfully. The abdominal symptoms subsided after this procedure. In AMI that is diagnosed early, endovascular stenting should be considered as an alternative treatment to the surgical approach that avoids the need for surgical bowel resection.

  17. Effect of percutaneous transluminal coronary angioplasty on coronary reserve

    SciTech Connect

    Lassar, T.; Hendrix, L.; Ray, G.; Schmidt, D.

    1984-01-01

    This study was done to assess the effect of percutaneous transluminal coronary angioplasty (PTCA) on regional myocardial perfusion (RMP) in the region distal to a stenosis in 48 patients. Quantitative RMP in ml/100g/min was measured from the washout of Xe-133 following selective injection into the involved coronary artery. After successful dilation, determined by a reduction in %stenosis to a less than or equal to 50% lesion and in pressure gradient across the lesion, the RMP measurement was repeated. In these patients, means %stenosis was 85% pre PTCA and 29% post PTCA with mean pressure gradient of 60 Hg pre PTCA and 21 mm Hg post PTCA. 21 of these 48 patients also had RMP measured after isoproterenol (ISO) both pre and post PTCA to increase myocardial oxygen demand to assess coronary reserve. Heart rate (HR) and systolic blood pressure (SBP) were constant pre and post PTCA which allowed a valid comparison. The results are presented. A group of 13 patients with normal coronary arteries and ventricular function showed a mean control RMP of 78 +- 15 and a mean ISO RMP of 140 +- 26. The data demonstrate that following successful PTCA quantitative RMP improves both at rest and with an ISO challenge and is similar to RMP in normal coronary arteries.

  18. Arterial healing response after angioplasty and its contributions to restenosis

    NASA Astrophysics Data System (ADS)

    Borst, Cornelius; van Erven, Lieselotte; Velema, Evelyn; Post, Mark J.

    1992-08-01

    Balloon angioplasty of coronary obstructions is limited by a 40% angiographic restenosis rate six months after the intervention. Myointimal hyperplasia is a major contributor to restenosis. In 77 normal rabbits we examined the question whether severe thermal interventional injury to the iliac artery wall would result in less myointimal hyperplasia than severe mechanical injury induced by balloon dilation. Eight weeks after percutaneous injury by electrical spark erosion, the metal laser probe, cw Nd:YAG laser energy through the sapphire contact probe, 90 degree(s)C RF heated balloon dilation, or standard balloon dilation the neointima thickness measured up to 380 micrometers . When thermally and mechanically damaged walls were compared, myointimal hyperplasia was similar. We conclude that in the normal rabbit the arterial wall healing response after any injury is neointima formation which is the vessel wall's expression of the general pattern of wound healing. It is inferred that alternative modes of injury in new recanalization techniques will lead to induced restenosis rates.

  19. Getreide, Brot und Feine Backwaren

    NASA Astrophysics Data System (ADS)

    von Grabowski, Hans-Uwe; Rolfe, Birgit

    Getreide und Getreideerzeugnisse sind ebenso wie Brot und Feine Backwaren nach dem Lebensmittel- und Futtermittel-Gesetzbuch (LFGB) [1] Lebensmittel im Sinne des Artikels 2 der VO (EG) Nr. 178/2002 (BasisVO) (s. auch Kap. 1.6/2.4.1/3.2). Gesetzlich festgelegte Begriffsbestimmungen gibt es für diese Lebensmittel nicht. Man muss sich daher allgemeiner Verkehrsauffassungen bedienen, wie sie von der Deutschen Lebensmittelbuch-Kommission in Form von Leitsätzen erarbeitet und veröffentlicht wurden [2]. Der Gesundheitsschutz und der Schutz des Verbrauchers vor Täuschung sind in der Basis-VO und dem LFGB geregelt.

  20. Reaction to injury following balloon angioplasty and intravascular stent placement in the canine femoral artery.

    PubMed

    Salam, T A; Taylor, B; Suggs, W D; Hanson, S R; Lumsden, A B

    1994-05-01

    Intravascular stents are used clinically as an adjunct to coronary and iliac angioplasty. This study was performed to evaluate the thrombogenicity and intimal hyperplasia incited by stents deployed in non-injured and in balloon-injured femoral arteries in the canine model. Medinvent stents (4 mm) were placed in the femoral arteries bilaterally in five mongrel dogs via cut down. This was preceded by balloon catheter angioplasty of the stent site on one side. Platelet deposition was measured at 30, 60, and 90 minutes and at 24 and 48 hours after stent placement, using gamma camera imaging of Indium111 platelets. The animals were killed after 2 months using a pressure perfusion technique, and the stents harvested. All vessels were patent at the time of harvest. Neointimal thickness was measured by computer image analysis. Platelet deposition was significantly increased on the angioplastied side compared to the non-angioplastied side at 60 minutes (5.67 x 10(9) +/- 1.4 versus 2.17 x 10(9) +/- 0.5 platelets/cm; P < 0.05), at 90 minutes (8.13 x 10(9) +/- 1.8 versus 2.33 x 10(9) +/- 0.6 platelets/cm; P < 0.05), and at 24 hours (stent-to-blood ratio = 15.86 +/- 6.3 versus 3.75 +/- 1.5; P < 0.05). Neointimal thickness was also significantly greater on the side of combined angioplasty and stent placement (0.45 +/- 0.21 mm versus 0.33 +/- 0.09 mm; P < 0.05). These results demonstrate that placement of intravascular stents in normal arteries is associated with a certain degree of thrombogenicity and formation of neointimal hyperplasia. Combining balloon angioplasty with stent placement significantly augments both thrombogenicity and production of intimal hyperplasia.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8161086

  1. [Percutaneous coronary Excimer laser angioplasty in patients with coronary heart disease].

    PubMed

    Karsch, K R; Haase, K K; Mauser, M; Ickrath, O; Voelker, W; Baumbach, A; Seipel, L

    1990-07-01

    To verify the efficacy and safety of percutaneous coronary excimer laser angioplasty in patients with coronary artery disease a prospective study was conducted in 60 patients. The application of laser light was possible in 55 of the 60 patients. A novel 1.4-mm diameter catheter with 20 quartz fibers of 100-microns diameter, each arranged concentrically around a central lumen suitable for an 0.014-inch flexible guide wire was used. The light source was a commercial excimer laser emitting energy at a wavelength of 308 nm, with a pulse duration of 60 ns. The laser was operated at 20 Hz; mean energy transmission was 30 +/- 5 mJ/mm2. In 23 of the 55 patients treated with excimer laser energy the qualitative angiographic results were sufficient. In 32 patients additional balloon angioplasty was necessary, either because of an insufficient result or due to vessel closure after laser ablation. In 47 of the 55 patients control angiography was performed within the 6-month follow-up period. Rate of restenosis was higher in patients treated with laser ablation and subsequent balloon angioplasty (16 of 28) than in patients treated with laser ablation alone (6 of 19). Results of the 6-month observation period suggest that 1) coronary excimer laser angioplasty in combination with subsequent balloon angioplasty results in a considerable increase of the restenosis rate; 2) the exclusive use of laser ablation also results in a restenosis rate comparable to balloon angioplasty alone; and 3) the impact of this new method using improved application systems and higher energy transmission has to be determined in further studies. PMID:2399764

  2. Does Coronary Stenting Following Balloon Angioplasty Improve Myocardial Fractional Flow Reserve?

    SciTech Connect

    Takeuchi, Masaaki; Himeno, Etsuro

    1998-11-15

    Purpose: Suboptimal distal coronary flow reserve after successful balloon angioplasty has been attributed to angiographically unrecognized inadequate lumen expansion, and adjunct coronary stenting has been shown to improve coronary flow reserve. The aim of this study was to investigate whether myocardial fractional flow reserve (FFRmyo) would increase further after coronary stenting compared with balloon angioplasty alone in the same patient group. Methods: FFRmyo and quantitative coronary angiography were obtained before and after pre-stent balloon dilation, and again after stent placement in 11 patients (7 left anterior descending artery, 3 right coronary artery and 1 left circumflex artery). FFRmyo was calculated as the ratio of Pd/Pa during intracoronary adenosine 5'-triphosphate (50 {mu}g and 20 {mu}g in the left and right coronary arteries, respectively)-induced maximum hyperemia, where Pd represents mean distal coronary pressure measured by a 2.1 Fr infusion catheter and Pa represents mean aortic pressure measured by the guiding catheter. Results: Percent diameter stenosis significantly decreased after balloon angioplasty (74% {+-} 15% vs 37% {+-} 17%, p < 0.001), and decreased further after stent placement (18% {+-} 10%, p < 0.001 vs baseline and balloon angioplasty). FFRmyo after coronary stenting (0.85 {+-} 0.09) was significantly higher than that at baseline (0.51 {+-} 0.16, p < 0.001) and after balloon angioplasty (0.77 {+-} 0.11, p < 0.05). There was a significant correlation between angiographic variables and FFRmyo. The increase in lumen dimensions after coronary stenting was followed by a further significant improvement of FFRmyo. Conclusion: These results suggest that coronary stenting may provide a more favorable functional status and lumen geometry of residual coronary stenosis compared with balloon angioplasty alone.

  3. Unternehmens- und Marktstatistik

    NASA Astrophysics Data System (ADS)

    Grömling, Michael; Scheinost, Ulrich

    Deutschland verfügt über ein gut ausgebautes System amtlicher und nicht amtlicher Unternehmens- und Marktstatistiken, das sich in einem fortwährenden Wandel befindet. Wird es sinnvoll genutzt, können für einzelne Marktteilnehmer wie für die gesamte Gesellschaft kostspielige Fehlentwicklungen vermieden werden. Dazu bedarf es eines sachkundigen Überblicks über die Vielfalt der Statistiken und der zwischen ihnen bestehenden Beziehungen sowie einer ständigen Anpassung an die wirtschaftliche Entwicklung. Als eine mögliche Orientierung kann der auf der Güter- und Faktorebene zu beobachtende Wandel dienen. Einer adäquaten Abbildung der ökonomischen Realität stehen in Deutschland mit seiner starken Verrechtlichung der Statistik jedoch mancherlei Schwierigkeiten im Wege. Teilweise tiefgreifende Reformbestrebungen sind vor allem auf europäischer Ebene im Gange. Als eine ergebnisorientierte Innovation für das Gesamtsystem der Unternehmens- und Marktstatistik wird ein modular aufgebautes System vorgestellt, das auch bei unterschiedlichen und sich wandelnden Rahmenbedingungen schrittweise realisiert werden kann.

  4. Datenintegration und Deduplizierung

    NASA Astrophysics Data System (ADS)

    Bleiholder, Jens; Schmid, Joachim

    In Unternehmen liegen viele Daten heutzutage immer seltener vollständig an einem einzigen physikalischen Ort vor, sondern sind weltweit verteilt. Dies liegt zum einen an der immer besser gewordenen Infrastruktur, die eine solche Verteilung auf einfache Art und Weise ermöglicht, und zum anderen an der Tatsache, dass viele Unternehmen weltweit tätig sind. So fallen Daten weltweit an, werden aber jeweils lokal - vor Ort - gespeichert. Daher müssen oft mehrere Datenquellen genutzt werden, um einen aktuellen, vollständigen und genauen Überblick über die vorhandenen Daten zu gewinnen. Datenintegration hilft, indem sie Daten aus mehreren Quellen zusammenführt und einheitlich darstellt. Diese integrierten Daten können genutzt werden, um sich einen Überblick über das Unternehmen zu verschaffen, z.B. wenn Unternehmen fusionieren und nur noch eine Kundendatenbank bestehen bleiben soll, oder wenn zu einem Kunden die Daten aus den verschiedenen Fachabteilungen zusammengeführt werden sollen. Anhand eines solchen Beispiels, der Integration von Kundendaten zu Kfz- und Lebensversicherungen erläutern wir im Folgenden einzelne Techniken.

  5. Reliability of pressure recordings via catheters used for transluminal coronary angioplasty.

    PubMed

    Busch, U W; Sebening, H; Beeretz, R; Heinze, R

    1984-06-01

    Because of common difficulties in obtaining adequate pressure tracing during transluminal coronary angioplasty, the pressure transmission characteristics of catheter systems used for angioplasty were determined. Transmission of cine wave pressures (0.2 to 14 Hz) and of arterial pressure pulses reproduced in vitro was evaluated. Following adequate elimination of air bubbles from the system, the Grüntzig dilatation catheters yielded satisfactory frequency response curves and thus good reproduction of arterial pressure waveforms. The Simpson-Robert catheter showed clearly inferior frequency response characteristics, explaining the more significant damping of the pressure tracings. However, mean pressures were reliably recorded with each type. PMID:15227077

  6. Balloon Angioplasty Optimization: Should We Measure Balloon Volume As Well As Pressure?

    SciTech Connect

    Shehab, M.; Michalis, L. K.; Rees, M. R.

    2008-01-15

    Purpose. To investigate the influence that measurement of balloon volume as a controlled variable in addition to balloon pressure has on the outcome of balloon angioplasty in an experimental model. Methods. One hundred and three segments of explanted normal porcine carotid arteries were obtained. Five were used as controls, and the remaining 98 were subjected to balloon angioplasty with simultaneous measurement of balloon volume and pressure. These arteries were randomized into two groups. In one group the endpoint of the angioplasty was determined by balloon pressure (pressure-limited group, PLG) and in the other group by balloon volume (volume-limited group, VLG). Pressure/volume curves for each procedure were constructed by continuous measurement of both parameters by a purpose-designed computer-controlled inflation device. The diameter of each arterial segment was measured by intravascular ultrasound (IVUS) and the ratio of the inflated balloon to arterial diameter calculated. Arterial appearances after angioplasty were recorded using IVUS. Results. The balloon volumes measured at the endpoint of angioplasty were significantly smaller in the PLG compared with the VLG (p < 0.001). Three types of pressure/volume curves were identified: A, B, and C. In the type A curves, IVUS identified fissures in 28% (17/60) and the examination was normal in 72% (43/60). In the type B curves, IVUS identified fissures in 44% (4/9), dissections in 22% (2/9), and the examination was normal in 33% (3/9). In the type C curves, IVUS identified fissures in 44% (4/9) and dissection in 56% (5/9) with no normal examinations. In undamaged arterial segments a very high correlation was achieved between balloon volume and the balloon/artery ratio (Pearson correlation = -0.979, R{sup 2} = 0.957, p < 0.0001, n = 27). Conclusion. The measurement of pressure and volume during angioplasty enabled the construction of pressure/volume curves that showed deviations from the curves obtained in air. The

  7. Prediction of Prolonged Hemodynamic Instability During Carotid Angioplasty and Stenting

    PubMed Central

    Rhim, Jong Kook; Park, Jeong Jin; Choi, Hyuk Jai; Cho, Young Dae; Sheen, Seung Hun; Jang, Kyung-Sool

    2016-01-01

    Purpose The aim of this study was to assess the risk factors of prolonged hemodynamic instability (HDI) after carotid angioplasty and stenting (CAS). Herein, a simplified predictive scoring system for prolonged HDI is proposed. Materials and Methods Sixty-six patients who had CAS from 2011 to 2016 at a single institution were evaluated. Prolonged HDI was defined as systolic blood pressure >160 mm Hg or <90 mm Hg or heart rate <50 beats/min, lasting over 30 minutes despite medical treatments. For the study, clinical data and radiologic data, including plaque morphology and stenosis were analyzed. Results Prolonged HDI was observed in 21 patients (31.8%). Multivariable analysis revealed that calcification (OR, 6.726; p=0.006), eccentric stenosis (OR, 3.645; p=0.047) and extensive plaque distribution (OR, 7.169; p=0.006) were related to prolonged HDI. According to these results, a simplified scoring scale was proposed based on the summation of points: 2 points for calcified plaque, 2 points for extensive plaque distribution, and 1 point for eccentric stenosis. The percentages of prolonged HDI according to the total score were as follows: score 0, 8.7%; score 1, 20.0%; score 2, 38.5%; score 3, 72.7%; score 4, 66.7%; score 5, 100%. From the analysis, the total score in patients with prolonged HDI was significantly higher than those without prolonged HDI (p<0.001). Conclusion Prolonged HDI can be associated with calcification of plaque, eccentric stenosis and extensive plaque distribution, and a simplified scoring system enables prediction of prolonged HDI according to our cohort. PMID:27621949

  8. Dobutamine stress--Doppler echocardiography before and after coronary angioplasty.

    PubMed

    el-Said, E S; Fioretti, P M; Roelandt, J R; McNeill, A J; Rijsterborgh, H; Forster, T; Di Mario, C; Linker, D T

    1993-08-01

    To determine if dobutamine-induced myocardial ischaemia causes abnormalities in Doppler parameters of left ventricular ejection and filling and to assess early effects of successful coronary angioplasty (PTCA) on these parameters, dobutamine stress echocardiography and Doppler studies were performed once in 11 normal volunteers and twice in 17 patients (within 1 day pre- and post-PTCA). Dobutamine induced wall motion abnormalities, ST changes and angina in 11, five and five patients, respectively, before and three, two and one patients, respectively, after PTCA. Doppler indices of both systolic and diastolic function were comparable at rest, before and after PTCA. Dobutamine induced similar increases in peak aortic velocity and average acceleration in healthy individuals (39% and 53%) and in patients with one-vessel disease both before (38% and 39%) and after PTCA (39% and 40%). In the three patients with multivessel disease, peak aortic velocity showed a blunted response (-0.3%) before PTCA but increased by 17% after PTCA, while acceleration decreased both before (12%) and after PTCA (14%). There were significant differences (P < 0.0001) between healthy individuals and pre-PTCA patients in the effect of dobutamine on peak early (E) filling velocity (+34% vs -19%), E-acceleration (+35% vs -26%), peak early to atrial filling velocity ratio (E/A) (-0.7% vs -37%) and diastolic time velocity integral (TVI) (+34% vs -22%). After PTCA, the response of Doppler diastolic indices improved during dobutamine, as shown by the increase in E and E-acceleration (+8%, +24%), respectively) and by the decline in the reduction of E/A and TVI (-17% and -10%, respectively). Thus, the response of Doppler diastolic parameters to dobutamine stress is a sensitive indicator of significant coronary disease and is superior to changes in ejection indices. Successful PTCA resulted in an improved diastolic filling response to dobutamine stress. PMID:8404930

  9. Salvage of Immature Arteriovenous Fistulas with Percutaneous Transluminal Angioplasty

    SciTech Connect

    Shin, Sung Wook; Do, Young Soo Choo, Sung Wook; Lieu, Wei Chiang; Choo, In-Wook

    2005-05-15

    The purpose of this study was to assess the value of percutaneous transluminal angioplasty (PTA) for the salvage of arteriovenous fistulas (AVFs) that fail to mature. From November 1998 to February 2003, 19 patients who were treated with PTA due to immature forearm AVFs were selected. Fistulography and PTA were performed via a retrograde transvenous approach after direct puncture of the fistular vein. Technical success was defined as less than a 30% residual stenosis, whereas clinical success was defined as the ability to perform at least one session of normal hemodialysis after PTA. Findings of fistulograms, success rates of PTA, and patency rates were evaluated. On initial fistulograms, stenoses were observed in all cases and 68% (13/19) of the stenoses were located in the perianastomotic area of these immature AVFs. The initial technical success rate was 84% (16/19). Technical failures comprised two patients with diffuse narrowing and segmental thrombosis of the cephalic veins and one case of elastic recoil of the anastomotic site stenosis after PTA. Two patients were immediately lost on follow-up. The remaining 14 cases underwent successful hemodialysis 0 to 33 (mean = 15) days after PTA, showing 74% (14/19) clinical success. Although accessory branch veins were noted in most cases (74%, 14/19), leaving them alone did not affect the maturation of AVFs following PTA. There was no significant procedural or late complication. Primary and secondary patency rates at 1 year were 61 and 82%, respectively. For those AVFs that failed to mature, there were stenoses along their vascular courses as underlying causes. For the percutaneous procedure, the retrograde transvenous approach was a reasonable one. As PTA is effective and quick for the salvation of immature AVFs, it can be considered a primary method for salvaging these immature AVFs.

  10. [Exercise tolerance in patients after successful percutaneous transluminal coronary angioplasty].

    PubMed

    Tsumoto, S; Nakagawa, Y; Asakuma, S; Naruse, H; Komasa, N; Ohyanagi, M; Tateishi, J; Yasutomi, N; Fujitani, K; Iwasaki, T

    1991-01-01

    In 32 patients with successful percutaneous transluminal coronary angioplasty (PTCA), we performed treadmill exercise tests (TMET) before and about one month after PTCA to assess the correlation between the improvement in coronary artery lesions and exercise tolerance. Either the Bruce protocol (B: n = 12) or the modified Bruce protocol (MB: n = 20) was used; with the latter being applied to patients whose cardiac function seemed depressed. In 15 patients, oxygen consumption (VO2) was measured by analyzing the expired gases, 13 patients underwent exercise thallium-201 myocardial perfusion scintigraphy before and after PTCA, whose results were compared with those of TMET. In both B and MB protocols, the treadmill walking time was significantly prolonged after PTCA, compared to that before PTCA (B: 7.4 +/- 1.3 vs 9.5 +/- 1.9, MB: 11.4 +/- 3.5 vs 12.7 +/- 3.5 min). Heart rates (HR) and rate pressure products (RPP) were significantly increased after PTCA in both protocols (HR B: 139 +/- 18 vs 154 +/- 17, MB: 121 +/- 20 vs 137 +/- 19 bpm, RPP B: 26,500 +/- 5,600 vs 30,300 +/- 6,700, MB: 19,400 +/- 6,200 vs 22,700 +/- 6,600 mmHg.bpm), however, systolic blood pressure did not change significantly after PTCA in either protocol. While there was a significant improvement in VO2 after PTCA (21.6 +/- 6.3 vs 25.7 +/- 4.2 ml/kg/min), the O2-pulse remained unchanged. Thallium-201 myocardial scintigraphy revealed improvement of myocardial perfusion in 8 of the 13 cases examined.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1841916

  11. Geologie der terrestrischen Planeten und Monde.

    NASA Astrophysics Data System (ADS)

    Stöffler, D.

    Contents: 1. Inhalt und Aufgabe der Planetologie. 2. Aufbau des Sonnensystems. 3. Methoden der Exploration und Analyse der Planeten und Monde. 4. Geologische Grundprozesse auf den terrestrischen Planeten und Monden. 5. Geologische Formationen der planetaren Oberflächen. 6. Gesteine und Mineralien der planetaren Krusten. 7. Der innere Aufbau der terrestrischen planetaren Körper. 8. Vergleichende geologische Entwicklungsgeschichte der terrestrischen Planeten und des Mondes. 9. Ursprung und Entstehung der terrestrischen planetaren Körper.

  12. Cutting-Balloon Angioplasty Versus Balloon Angioplasty as Treatment for Short Atherosclerotic Lesions in the Superficial Femoral Artery: Randomized Controlled Trial

    SciTech Connect

    Poncyljusz, Wojciech Falkowski, Aleksander; Safranow, Krzysztof Rac, Monika; Zawierucha, Dariusz

    2013-12-15

    Purpose: To evaluate the treatments of a short-segment atherosclerotic stenosis in the superficial femoral arteries with the cutting balloon angioplasty (CBA) versus conventional balloon angioplasty [percutaneous transluminal angioplasty (PTA)] in a randomized controlled trial. Material and Methods: The study group comprised 60 patients (33 men, 27 women; average age 64 years) with a short ({<=}5 cm) focal SFA de novo atherosclerotic stenosis associated with a history of intermittent claudication or rest pain. The primary end point of this study was the rate of binary restenosis in the treated segment 12 months after the intervention. All patients were evenly randomized to either the PTA or CBA treatment arms. Follow-up angiograms and ankle-brachial index (ABI) measurements were performed after 12 months. The evaluation of the restenosis rates and factors influencing its occurrence were calculated by logistic regression analysis. Results: In the intention-to-treat analysis, restenosis rates after 2-month follow-up were 9 of 30 (30 %) in the PTA group and 4 of 30 (13 %) in the CBA group (p = 0.117). In the actual treatment analysis, after exclusion of patients who required nitinol stent placement for a suboptimal result after angioplasty alone (5 patients in the PTA group and none in the CBA group), restenosis rates were 9 of 25 (36 %) and 4 of 30 (13 %), respectively (p = 0.049). In the intention-to-treat analysis there were also significant differences in ABI values between the PTA and CBA groups at 0.77 {+-} 0.11 versus 0.82 {+-} 0.12, respectively (p = 0.039), at 12 months. Conclusion: Based on the presented results of the trial, CBA seems to be a safer and more effective than PTA for treatment of short atherosclerotic lesions in the superior femoral artery.

  13. Technikwissenschaft - Erfinden und Entdecken

    NASA Astrophysics Data System (ADS)

    Linnemann, Gerhard

    Umrissen wird das allgemeine Ziel der Technikwissenschaft, konstruktiv zu verwerten und nicht-natürlich Entdeckbares zu erfinden. Wir befinden uns in einer Umwälzung der Technik im Verlauf der wissenschaftlich-technischen Revolution, auf dem Wege zu einem neuen Techniktyp. Dieser schafft und nutzt die künstliche Intelligenz. Dazu benötigt der in der Technik tätige Mensch spezielle Kenntnisse und Erfahrungen in kreativ-konstruktiver, -gestalterischer und erfinderischer Sicht mit dem Einsatz spezieller Strukturen und Sprachen. Vorschläge zur Arbeitsweise in der Technik werden gegeben.Translated AbstractTechnological Science-Invent and DiscoverThe general aim of engineering science is outlined to utilize results constructively and to invent something that cannot be discovered in nature. We are now in a period of transformation of technology in the course of scientific-technological revolution, on the way to a new type of technology. This new type creates and utilizes artificial intelligence. For this, man acitive in this field requires special knowledge and experiences in a creative, constructive, design-oriented and ultimately inventive way by deploying special structures and languages. There are also made some proposals concerning the method of working in the field of technology.

  14. Patentierung und Patentlage

    NASA Astrophysics Data System (ADS)

    Herrmann, Uwe

    Gewerbliche Schutzrechte nehmen in der nationalen Rechts- und Wirtschaftsordnung sowie auch auf internationaler Ebene stetig an Bedeutung zu. Sie dienen dem Schutz geistigen Eigentums und sind für jeden Gewerbetreibenden nicht nur im Hinblick darauf von Bedeutung, eigene Rechte zu sichern, sondern auch insofern von Relevanz, dass ein Verstoß gegen Rechte Dritter zu vermeiden ist. Zu den gewerblichen Schutzrechten gehören unter anderem Kennzeichenrechte, Geschmacksmusterrechte sowie die sogenannten technischen Schutzrechte in Form des Patents sowie des Gebrauchsmusters. Die folgenden Ausführungen befassen sich ausschließlich mit den technischen Schutzrechten und geben eine kurze Einführung in die Voraussetzungen, das Entstehen und den Wegfall sowie in die Wirkungen technischer Schutzrechte. Beleuchtet wird die Situation im Wesentlichen im Hinblick auf nationale technische Schutzrechte, d. h. auf Deutsche Patente und Gebrauchsmuster sowie auf Europäische Patente, die Schutz in Deutschland entfalten. Die Möglichkeit der Erlangung von Schutzrechten im außereuropäischen Ausland wird nur am Rande gestreift.

  15. Coronary flow reserve in the contralateral artery increases after successful coronary angioplasty in patients with spontaneously visible collateral vessels

    PubMed Central

    Kyriakides, Z; Antoniadis, A; Kolettis, T; Kremastinos, D

    1998-01-01

    Objective—To test the hypothesis that coronary flow reserve could increase in the angiographically normal contralateral artery after successful coronary angioplasty of an ipsilateral coronary artery.
Design—Coronary flow reserve was estimated using a Doppler flow guide wire, by giving intracoronary adenosine in the contralateral artery, before and 15 minutes after the end of angioplasty.
Setting—Tertiary referral centre.
Patients—31 patients, mean (SD) age 56 (11) years, with stable angina and single vessel disease, undergoing angioplasty of the right coronary or the left anterior descending artery.
Results—In the contralateral artery baseline average peak velocity was 21 (9) cm/s before angioplasty and decreased to 12 (6) cm/s after (p < 0.005), while hyperaemic average peak velocity was 47 (19) cm/s before and decreased to 34 (15) cm/s after (p < 0.005). However, coronary flow reserve in the contralateral artery was 2.4 (0.7) before angioplasty and increased to 2.9 (0.6) after (p < 0.05). The contralateral coronary flow reserve after angioplasty increased by 0.8 (0.4) in 11 patients with visible collaterals before angioplasty and by 0.3 (0.6) in the remaining patients without visible collaterals (p < 0.05). Blood pressure and heart rate were unchanged after the procedure.
Conclusions—Coronary flow reserve in an angiographically normal contralateral artery increases after successful coronary angioplasty of the ipsilateral artery in patients with spontaneously visible collateral vessels before the procedure.

 Keywords: coronary flow reserve;  contralateral coronary artery;  angioplasty PMID:9930051

  16. [A myocardial infarction during pregnancy treated by percutaneous transluminal coronary angioplasty and stent implantation. Case report].

    PubMed

    Dubois, N; de Muylder, X; Foading, B

    2007-01-01

    Acute myocardial infarction is an un-frequent event during pregnancy. It clearly causes an increase in both maternal and fetal mortality. We describe a case of pregnancy complicated during the second trimester by an acute myocardial infarction witch was treated by percutaneous transluminal coronary angioplasty combined with stenting. The challenge involved in managing this condition during pregnancy is briefly discussed. PMID:17567523

  17. Unusual Case of Exercise-Induced ST Segment Elevation Alternans: Successful Treatment with Transluminal Angioplasty

    PubMed Central

    Mammen, George; Krajcer, Zvonimir; Leachman, Robert D.

    1983-01-01

    Alternans of the ST segment is sometimes observed in experimental studies but is rarely seen in the clinical setting. Described is a case of exercise-induced ST segment elevation alternans that was successfully treated with transluminal coronary artery angioplasty. Theories regarding the cause and mechanism of this phenomenon are discussed. Images PMID:15227140

  18. Influence of elastic recoil on restenosis after successful coronary angioplasty in unstable angina pectoris.

    PubMed

    Ardissino, D; Di Somma, S; Kubica, J; Barberis, P; Merlini, P A; Eleuteri, E; De Servi, S; Bramucci, E; Specchia, G; Montemartini, C

    1993-03-15

    The elastic behavior of the dilated coronary vessel has been reported to affect the immediate results of coronary angioplasty. To determine whether elastic recoil may also influence the long-term restenosis process, 98 consecutive patients with unstable angina and 1-vessel disease were studied. An automated coronary quantitative program was used for the assessment of balloon and coronary luminal diameters. Elastic recoil was defined as the percent reduction between minimal balloon diameter at the highest inflation pressure and minimal lesion diameter immediately after coronary angioplasty. Follow-up coronary arteriography was performed 8 to 12 months after the procedure in all patients. The mean elastic recoil averaged 17.7 +/- 16% and was correlated to the degree of residual stenosis immediately after coronary angioplasty (r = 0.64; p < 0.001). Restenosis, defined as > 50% diameter stenosis at follow-up, developed in 53 patients (54%). There was no correlation between the degree of elastic recoil and the changes in minimal lesion diameter observed during follow-up, whereas a positive correlation between the amount of elastic recoil and the incidence of restenosis was documented (r = 0.84; p < 0.05). Thus, the elastic properties of the dilated vessel do not influence the active process of restenosis. However, because elastic recoil negatively influences the initial results of angioplasty, it is more likely that further reductions in lumen diameter during follow-up can reach a threshold of obstruction considered critical for a binary definition of restenosis. PMID:8447261

  19. Vertebral artery origin angioplasty and primary stenting: safety and restenosis rates in a prospective series

    PubMed Central

    Cloud, G; Crawley, F; Clifton, A; McCabe, D; Brown, M; Markus, H

    2003-01-01

    Objectives: To report a single centre ongoing experience of endovascular treatment for atherosclerotic vertebral artery origin stenosis in a series of symptomatic patients, with follow up imaging to determine the incidence of restenosis. Methods: 14 patients with vertebral artery origin stenosis on catheter angiography were treated. Angioplasty without stenting was undertaken in the first four patients, all of whom had follow up catheter angiography at one year. Subsequently, patients were treated by primary stenting and followed up with colour Doppler ultrasound examination. Results: The procedure was technically successful in all treated arteries, with no immediate complications. The degree of stenosis was reduced from (mean (SD)) 73 (18)% before treatment to 21 (26)% immediately after treatment in the angioplasty alone group (p = 0.059). In the primary stenting patients, the severity of stenosis was reduced from 82 (8)% to 13 (13)% immediately after treatment (p < 0.001). Restenosis to 70% or greater occurred at one year in all four patients initially treated by angioplasty without stenting. One patient subsequently developed further symptoms and was retreated by stenting. One of the 10 patients treated by primary stenting developed restenosis. None of the remaining patients had further posterior circulation ischaemic symptoms during a mean follow up period of 33.6 months (range 1 to 72 months). Conclusions: Restenosis occurs often after vertebral artery origin balloon angioplasty without stenting but is uncommon after stenting. Primary stenting is therefore recommended to maintain patency at this site, and had a low complication rate in this series. PMID:12700299

  20. Risks and benefits of coronary angioplasty: the patients perspective: a preliminary study.

    PubMed Central

    Kee, F; McDonald, P; Gaffney, B

    1997-01-01

    OBJECTIVES: To describe what cardiac patients in Northern Ireland understand to be the benefits of coronary angioplasty and assess the extent to which they have been able to make informed choices about their treatment. DESIGN: An interview based questionnaire survey completed after the patients had undergone coronary angiography, within hours of treatment counselling. SUBJECTS: 150 patients consecutively recruited from two regional cardiology centres in Belfast, Northern Ireland. MAIN OUTCOME MEASURES: The perceived complication rate and the perceived gain in life expectancy from coronary angioplasty. RESULTS: Although most subjects had asked the consultant questions, 70% (n = 104) thought that they contributed negligibly or not at all to the treatment decision. Although 75% (n = 112) recalled discussing the complication rate from the procedure, only 27% accurately estimated this rate (as between 0.5 and 1.5%). Eighty eight per cent (n = 131) thought that their mortality risks would be substantially or greatly reduced by having the procedure. The patients anticipated a gain in life expectancy of some 10 years (median) and this was significantly in excess of the potential gain in life expectancy which dietary prudence to lower blood cholesterol, not smoking, and taking more exercise might produce (median 5 years respectively; P < 0.0001, Wilcoxon matched pairs signed rank test). CONCLUSIONS: Patients vastly overrate the capacity of angioplasty to control their disease: angioplasty is seen as more effective than risk factor modification. PMID:10173770

  1. Therapeutic Consequences of Variation in Intraarterial Pressure Measurements After Iliac Angioplasty

    SciTech Connect

    Tetteroo, Eric; Haaring, Cees; Engelen, Andries D. van; Graaf, Yolanda van der; Mali, Willem P.T.M.

    1997-11-15

    Purpose: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically suboptimal iliac angioplasty. Methods: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD {+-} SD) and repeatability coefficient (2 x SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting where there was a residual pressure gradient > 10 mmHg. Results: MD {+-} SD for repeated measurements at rest and during flow augmentation were 0 {+-} 2 mmHg and 1 {+-} 3 mmHg, respectively. Repeatability coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 {+-} 7 mmHg at rest and 17 {+-} 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions. Conclusion: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant stenosis after angioplasty.

  2. Percutaneous Mural Fenestration and Angioplasty for the Treatment of a Refractory Hemodialysis-Related Venous Stenosis

    SciTech Connect

    Denison, Gregory L. Funaki, Brian

    2006-12-15

    Venous stenoses are the leading cause of dialysis graft and mature dialysis fistula malfunction. We report a simple, inexpensive technique for treating stenoses that are refractory to conventional balloon angioplasty and present a case in which this technique was successfully applied.

  3. Cutting-Balloon Angioplasty in Transplant Renal Artery Stenosis as First-Line Treatment in the Early Postoperative Period

    SciTech Connect

    Ucar, Adem; Yahyayev, Aghakishi; Bakkaloglu, Huseyin; Agayev, Ayaz; Aydin, Ali Emin; Rozanes, Izzet

    2011-02-15

    Percutaneous transluminal angioplasty has been successfully used for the treatment of transplant renal artery stenosis (RAS). Cutting-balloon angioplasty (CBA) is being used as a second option in pressure-resistant stenosis. It is thought that CBA is less traumatic and therefore restenosis occurs less frequently than in conventional angioplasty. This case report describes the unusual use of a cutting balloon in transplant RAS as a first option in the early postoperative period. Long-term follow-up data are also presented.

  4. Venture Kapital und Life Science

    NASA Astrophysics Data System (ADS)

    Moss, Sebastian; Beermann, Christian

    Um sich weiter im internationalen Wettbewerb behaupten zu können, müssen deutsche Unternehmen heute in Schlüsseltechnologien wie die Medizintechnik und die Biotechnologie, zusammenfassend unter dem Begriff der Life Sciences bekannt, investieren. Eine führende Wettbewerbsposition erfordert immer die konsequente Weiterentwicklung von Produkten und Lösungen, um Innovationspotenziale in medizinische Verfahren umzusetzen. Die damit unmittelbar verbundenen hohen Ausgaben für Forschung und Entwicklung stellen ein bedeutendes Problem junger Life Science Unternehmen dar. Vor allem die, verglichen mit nicht-medizinischen Branchen, längeren Forschungs- und Entwicklungszyklen in der Frühphase eines Life Science Unternehmens und die längere Dauer bis zur Profitabilität erhöhen das Risiko der Finanzinvestoren. Die Zeitdauer, um ein medizinisches Produkt bis zur Marktreife zu entwickeln und letztlich auf dem Markt anzubieten, kann aufgrund der notwendigen intensiven Forschung nur unscharf geplant werden und erhöht die Unsicherheit über den Zeitpunkt der ersten Einnahmen. Damit verschärfen sich gerade im Life Science Bereich allgemeine Problematiken von Gründungs- und Wachstumsfinanzierungen wie starke Informationsasymmetrien zwischen Gründer und potentiellen Kapitalgebern. Oftmals ist die Entwicklung einer innovativen Technologie abhängig von einzelnen Personen, von deren Wissen und Engagement die Umsetzung und der Erfolg eines gesamten Produktkonzeptes abhängen.

  5. Recombinant Human Elastase Alters the Compliance of Atherosclerotic Tibial Arteries After Ex Vivo Angioplasty

    PubMed Central

    Bingham, Karen; Moss, Emma; Gottlieb, Daniel P.; Wong, Marco D.; Bland, Kimberly S.; Franano, F. Nicholas

    2016-01-01

    Purpose: This study was designed to determine whether vonapanitase (formerly PRT-201), a recombinant human elastase, treatment can fragment the protein elastin in elastic fibers and cause dilation of atherosclerotic human peripheral arteries subjected to ex vivo balloon angioplasty. Materials and Methods: Seven patients undergoing lower limb amputation for peripheral artery disease or who died and donated their bodies to science donated 11 tibial arteries (5 anterior, 6 posterior) for this study. All arteries were atherosclerotic by visual inspection. The arteries underwent ex vivo balloon angioplasty and thereafter were cut into rings and studied on wire myographs where the rings were stretched and tension was recorded. After treatment with vonapanitase 2 mg/mL or vehicle control, myography was repeated and the rings were then subject to elastin content measurement using a desmosine radioimmunoassay and elastic fiber visualization by histology. The wire myography data were used to derive compliance, stress-strain, and incremental elastic modulus curves. Results: Vonapanitase treatment reduced elastin (desmosine) content by 60% and decreased elastic fiber histologic staining. Vonapanitase-treated rings experienced less tension at any level of stretch and as a result had shifts in the compliance and stress-strain curves relative to vehicle-treated rings. Vonapanitase treatment did not alter the incremental elastic modulus curve. Conclusions: Vonapanitase treatment of atherosclerotic human peripheral arteries after ex vivo balloon angioplasty fragmented elastin in elastic fibers, decreased tension in the rings at any level of stretch, and altered the compliance and stress-strain curves in a manner predicting arterial dilation in vivo. Based on this result, local treatment of balloon angioplasty sites may increase blood vessel diameter and thereby improve the success of balloon angioplasty in peripheral artery disease. PMID:26745001

  6. Retrospective Study of Rapid-Exchange Monorail Versus Over-the-Wire Technique for Femoropopliteal Angioplasty

    SciTech Connect

    Jahnke, Thomas Schaefer, Jost Philipp; Bolte, Hendrik; Schaefer, Fritz; Michalek, Jens; Charalambous, Nicholas; Sapoval, Marc; Mueller-Huelsbeck, Stefan

    2008-09-15

    PurposeThe purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty.Materials and MethodsDemographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis <30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%).ResultsTechnical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluorocopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and {>=}6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique.ConclusionWe conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

  7. Primary Angioplasty Versus Stenting for Endovascular Management of Intracranial Atherosclerotic Disease Following Acute Ischemic Stroke

    PubMed Central

    Villwock, Mark R.; Padalino, David J.; Ramaswamy, Raghu; Deshaies, Eric M.

    2016-01-01

    Background The future of neuroendovascular treatment for intracranial atherosclerotic disease (ICAD) has been debated since the results of SAMMPRIS reflected poor outcomes following endovascular therapy. There is currently a large spectrum of current management strategies. We compared historical outcomes of patients with ICAD and stroke that were treated with angioplasty-alone versus stent placement. Methods We extracted a population from the Nationwide Inpatient Sample (NIS) (2005–2011) and the National Inpatient Sample (NIS) (2012) composed of patients with ICAD and infarction that were admitted nonelectively and received endovascular revascularization. Patients treated with thrombectomy or thrombolysis were excluded. Categorical variables were compared with Chi-squared tests. Binary logistic regression was performed to evaluate mortality while controlling for age, sex, severity, and comorbidities. Results About 2059 admissions met our criteria. A majority were treated via stent placement (71%). Angioplasty-alone had significantly higher mortality (17.6% vs. 8.4%, P<0.001), but no difference in iatrogenic stroke rate (3.4% vs. 3.6%, P=0.826), compared to stent placement. The adjusted odds ratio of mortality for stented patients was 0.536 (95% CI: 0.381–0.753, P<0.001) in comparison to patients treated with angioplasty alone. Conclusions This study found the risk of mortality to be elevated following angioplasty alone in comparison to revascularization with stent placement, without a corresponding significant difference in iatrogenic stroke rate. This may represent selection bias due to patient characteristics not defined in the database, but it also may indicate that patients with ICAD and acute stroke have increased odds of stenosis that is refractory to angioplasty alone and have a high risk of mortality without revascularization. PMID:27403216

  8. A New Approach: Regional Nerve Blockade for Angioplasty of the Lower Limb

    SciTech Connect

    Marcus, A.J. Lotzof, K.; Kamath, B.S.K.; Shanthakumar, R.E.; Munir, N.; Loh, A.; Bird, R.; Howard, A.

    2006-04-15

    Purpose. An audit study investigated the pilot use of regional nerve block analgesia (as an alternative to sedative/opiate, general or central neuraxial anesthesia) performed by radiologists with the assistance of imaging techniques during complex prolonged angiography. Methods. Radiologists were trained by anesthetic consultants to administer and use lower limb peripheral nerve block for difficult prolonged angioplasty procedures for patients with severe lower limb rest pain who were unable to lie in the supine position. In a pilot study 25 patients with limb-threatening ischemia received sciatic and femoral nerve blockade for angioplasty. The technique was developed and perfected in 12 patients and in a subsequent 13 patients the details of the angiography procedures, peripheral anesthesia, supplementary analgesia, complications, and pain assessment scores were recorded. Pain scores were also recorded in 11 patients prior to epidural/spinal anesthesia for critical ischemic leg angioplasty. Results. All patients with peripheral nerve blockade experienced a reduction in their ischemic rest pain to a level that permitted angioplasty techniques to be performed without spinal, epidural or general analgesia. In patients undergoing complex angioplasty intervention, the mean pain score by visual analogue scale was 3.7, out of a maximum score of 10. Conclusions. The successful use of peripheral nerve blocks was safe and effective as an alternative to sedative/opiate, epidural or general anesthesia in patients undergoing complex angiography and has optimized the use of radiological and anesthetic department resources. This has permitted the frequent radiological treatment of patients with limb-threatening ischemia and reduced delays caused by the difficulty in enlisting the help of anesthetists, often at short notice, from the busy operating lists.

  9. Instability of Reference Diameter in the Evaluation of Stenosis After Coronary Angioplasty: Percent Diameter Stenosis Overestimates Dilative Effects Due to Reference Diameter Reduction

    SciTech Connect

    Hirami, Ryouichi; Iwasaki, Kohichiro; Kusachi, Shozo; Murakami, Takashi; Hina, Kazuyoshi; Matano, Shigeru; Murakami, Masaaki; Kita, Toshimasa; Sakakibara, Noburu; Tsuji, Takao

    2000-03-15

    Purpose: To examine changes in the reference segment luminal diameter after coronary angioplasty.Methods: Sixty-one patients with stable angina pectoris or old myocardial infarction were examined. Coronary angiograms were recorded before coronary angioplasty (pre-angioplasty) and immediately after (post-angioplasty), as well as 3 months after. Artery diameters were measured on cine-film using quantitative coronary angiographic analysis.Results: The diameters of the proximal segment not involved in the balloon inflation and segments in the other artery did not change significantly after angioplasty, but the reference segment diameter significantly decreased (4.7%). More than 10% luminal reduction was observed in seven patients (11%) and more than 5% reduction was observed in 25 patients (41%). More than 5% underestimation of the stenosis was observed in 22 patients (36%) when the post-angioplasty reference diameter was used as the reference diameter, compared with when the pre-angioplasty measurement was used and more than 10% underestimation was observed in five patients (8%).Conclusion: This study indicated that evaluation by percent diameter stenosis, with the reference diameter from immediately after angioplasty, overestimates the dilative effects of coronary angioplasty, and that it is thus better to evaluate the efficacy of angioplasty using the absolute diameter in addition to percent luminal stenosis.

  10. Tipps und Tricks

    NASA Astrophysics Data System (ADS)

    Häger, Wolfgang; Bauermeister, Dirk

    Hier wollen wir einige uns nützlich erscheinende Hinweise zur Arbeit mit dem Inventor geben. Dabei geht es vor allem darum, das Arbeiten mit dem Inventor zu vereinfachen. Die Beispiele stellen eine unvollständige Aufzählung dar und sollen dazu anregen, nach alternativen Vorgehensweisen zu suchen (hier sei noch einmal ausdrücklich auf das Internet verwiesen).

  11. Arbeitsgestaltung und Mitarbeiterqualifizierung

    NASA Astrophysics Data System (ADS)

    Weiss-Oberdorfer, Werner; Hörner, Barbara; Holm, Ruth; Pirner, Evelin

    Die Wertkette gliedert ein Unternehmen in strategisch relevante Tätigkeiten, um dadurch Kostenverhalten sowie vorhandene und potenzielle Differenzierungsquellen zu verstehen. Wenn ein Unternehmen diese strategisch wichtigen Aktivitäten billiger oder besser als seine Konkurrenten erledigt, verschafft es sich einen Wettbewerbsvorteil." Michael Porter, 1985

  12. Kometen und Asteroiden

    NASA Astrophysics Data System (ADS)

    Borgeest, Ulf; Staude, Jakob; Hahn, Gerhard; Harris, Alan W.; Jaumann, Ralf; Köhler, Ulrich; Kührt, Ekkehard; Schulz, Rita; Neukum, Gerhard; Arnold, Gabriele; Keller, Horst Uwe; Denk, Tilmann; Müller, Thomas; Wulff, André; Maruhn, Nicolaus; Fischer, Daniel; Trieloff, Mario; Althaus, Tilmann

    Contents: Die Kleinkörper des Sonnensystems. Kern, Koma und Schweife. Ziele der Planetenforschung. ROSETTA: Naherkundung von Kometen. Asteroiden: Trümmer aus planetarer Urzeit. Kleinkörper im Infrarotweltall. Selbs beobachten! Apocalypse - not now! Meteoriten - Boten aus der Urzeit des Sonnensystems.

  13. Balloon Angioplasty - The Legacy of Andreas Grüntzig, M.D. (1939-1985).

    PubMed

    Barton, Matthias; Grüntzig, Johannes; Husmann, Marc; Rösch, Josef

    2014-01-01

    In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939-1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called "percutaneous transluminal dilatation". Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920-1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40(th) anniversary of balloon angioplasty, we summarize Grüntzig's life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter's first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig's former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated his 75(th

  14. Is Angiosome-Targeted Angioplasty Effective for Limb Salvage and Wound Healing in Diabetic Foot? : A Meta-Analysis

    PubMed Central

    2016-01-01

    Purpose Given that the efficacy of employing angiosome-targeted angioplasty in the treatment of diabetic foot remains controversial, this study was conducted to examine its efficacy. Methods We performed a systematic literature review and meta-analysis using core databases, extracting the treatment modality of angiosome-targeted angioplasty as the predictor variable, and limb salvage, wound healing, and revision rate as the outcome variables. We used the Newcastle-Ottawa Scale to assess the study quality, along with the Cochrane Risk of Bias Tool. We evaluated publication bias using a funnel plot. Results The search strategy identified 518 publications. After screening these, we selected four articles for review. The meta-analysis revealed that overall limb salvage and wound healing rates were significantly higher (Odds ratio = 2.209, 3.290, p = 0.001, p<0.001) in patients who received angiosome-targeted angioplasty than in those who received nonangiosome-targeted angioplasty. The revision rate between the angiosome and nonangiosome groups was not significantly different (Odds ratio = 0.747, p = 0.314). Conclusion Although a further randomized controlled trial is required for confirmation, angiosome-targeted angioplasty in diabetic foot was more effective than nonangiosome-targeted angioplasty with respect to wound healing and limb salvage. PMID:27441570

  15. [Percutaneous transluminal laser angioplasty in peripheral arterial occlusive disease--development of a new laser catheter system].

    PubMed

    Neubaur, T; Klepzig, M; Strauer, B E

    1988-04-01

    Percutaneous laser angioplasty in arterial occlusive disease has lately been performed clinically for the first time. Perforation of the arterial wall and formation of aneurysms are serious risks. Two novel laser catheters for laser angioplasty with minimized perforation risk are presented. Catheter I (5F) and II (6.3F) are designed in the same manner. The distal tip of these catheters is ovally formed and marked by a small X-ray dense metal ring. The silica fiber has a core diameter of 400 micron (I) respectively 600 micron (II). Its tip is also marked X-ray densely and therefore the position of the fiber tip can be controlled exactly during laser angioplasty. Using a guide wire and applicating short laser pulses the perforation risk can be minimized. In a total of 132 atherosclerotic stenosed or obstructed human arteries laser angioplasty was performed in vitro using a Nd:YAG laser. There were two perforations (1.5%). The degree of stenosis was reduced from 87 (90)% to 54 (52)%. Using the 600-micron-fiber (catheter II) the velocity of laser angioplasty was increased 2.5 times compared to laser angioplasty using the 400-micron-fiber. PMID:2968724

  16. Wirkstoffe, Medikamente und Mathematische Bildverarbeitung

    NASA Astrophysics Data System (ADS)

    Bauer, Günter J.; Lorenz, Dirk A.; Maaß, Peter; Preckel, Hartwig; Trede, Dennis

    Die Entwicklung neuer Medikamente ist langwierig und teuer. Der erste Schritt ist hierbei die Suche nach neuen Wirkstoffkandidaten, die für die Behandlung bislang schwer therapierbarer Krankheiten geeignet sind. Hierfür stehen der Pharma- und Biotechnologieindustrie riesige Substanzbibliotheken zur Verfügung. In diesen Bibliotheken werden die unterschiedlichsten Substanzen gesammelt, die entweder synthetisch hergestellt oder aus Pilzen, Bakterienkulturen und anderen Lebewesen gewonnen werden können.

  17. Spontaneous Coronary Dissection: “Live Flash” Optical Coherence Tomography Guided Angioplasty

    PubMed Central

    Bento, Angela Pimenta; Fernandes, Renato Gil dos Santos Pinto; Neves, David Cintra Henriques Silva; Patrício, Lino Manuel Ribeiro; de Aguiar, José Eduardo Chambel

    2016-01-01

    Optical Coherence tomography (OCT) is a light-based imaging modality which shows tremendous potential in the setting of coronary imaging. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndrome (ACS). The diagnosis of SCAD is made mainly with invasive coronary angiography, although adjunctive imaging modalities such as computed tomography angiography, IVUS, and OCT may increase the diagnostic yield. The authors describe a clinical case of a young woman admitted with the diagnosis of ACS. The ACS was caused by SCAD detected in the coronary angiography and the angioplasty was guided by OCT. OCT use in the setting of SCAD has been already described and the true innovation in this case was this unique use of OCT. The guidance of angioplasty with live and short images was very useful as it allowed clearly identifying the position of the guidewires at any given moment without the use of prohibitive amounts of contrast. PMID:26989520

  18. Intravascular ultrasound-guided central vein angioplasty and stenting without the use of radiographic contrast agents.

    PubMed

    Matthews, Ray; Thomas, Joseph

    2008-05-01

    Patients with contraindications to iodinated radiographic contrast agents present a significant challenge during endovascular intervention. A 46-year-old man with end-stage renal disease and a normally functioning left upper extremity arteriovenous fistula presented with severe left arm edema. The patient's history included repeated severe anaphylactoid reactions with severe respiratory distress upon exposure to iodinated contrast. In an attempt to avoid the use of iodinated contrast, angioplasty and stent placement of a severe central venous stenosis were performed using only fluoroscopy and intravascular sonography. In patients unable to receive iodinated contrast secondary to anaphylactoid reactions, intravascular sonography can be used to guide angioplasty and stenting of central venous stenosis. PMID:18286503

  19. Percutaneous Angioplasty of the Sole Patent Cerebral Artery in Two Patients with Takayasu’s Aortoarteritis

    PubMed Central

    Varghese, Kiron; Adhyapak, Srilakshmi M.

    2016-01-01

    We report two female patients with Takayasu’s aortoarteritis, who presented with symptoms of cerebral ischemia due to critical stenosis of the sole patent cerebral artery. Both had occlusion of both vertebral arteries and one carotid artery with critical stenosis of the other carotid artery and presented with hemiparesis contralateral to the patent but stenosed cerebral artery. They also had transient ischemic attacks attributable to the culprit vessel. In the first patient, balloon angioplasty alone was not successful, and hence, a self-expanding stent was deployed in the right common carotid artery. In the second patient, successful balloon angioplasty was performed for the left common carotid artery. Distal protection devices were not used, and neither patient experienced any periprocedural neurological event. Clinical follow-up at six months revealed no significant cerebral events. PMID:27042151

  20. Stenting of a renal artery stenosis achieves better relief of the obstructive lesion than balloon angioplasty.

    PubMed

    Dorros, G; Prince, C; Mathiak, L

    1993-07-01

    A balloon-expandable (Palmaz-Schatz) stainless steel stent was utilized following balloon angioplasty (PTRA) to determine if the obstructive lesion, using quantitative methods (automated measuring the diameter stenosis, and transstenotic peak systolic and mean pressure gradients), was significantly further reduced or abolished. Hemodynamic transstenotic gradient and stenoses measurements were made during 21 renal artery stenting procedures; prior and following PTRA, and subsequent to stent deployment. The stent sizes placed in the renal arteries were 5 mm (19%), 6 mm (67%), and 7 mm (14%). The results were as follows: [table: see text] The balloon-expandable (Palmaz-Schatz) stent significantly further reduced, and in fact effectively abolished, the obstructive renal artery lesion in comparison to balloon angioplasty (PTRA). The stent's effectiveness with regard lesion recurrence, maintenance, and preservation of renal function; cure or improved management of hypertension; and survival will be determined by careful clinic follow-up. PMID:8402841

  1. Characterization of vascular strain during in-vitro angioplasty with high-resolution ultrasound speckle tracking

    PubMed Central

    2010-01-01

    Background Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens. Methods Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data. Results Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R2 value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated. Conclusion These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue. PMID:20727172

  2. [Catheter therapy in patients with stable angina pectoris. Results of 662 coronary angioplasties].

    PubMed

    Veselka, J; Tesar, D; Urbanová, T; Honĕk, T; Neuwirth, J

    2000-12-01

    Coronary angioplasty supplemented by implantation of a stent has become a standard therapeutic method in patients with stable angina pectoris. The authors analyzed the spectrum of patients indicated for this treatment, its successfulness and complications of catheterizations. In the course of a two-year period the authors implemented 662 catheterizations in 602 patients with stable angina. 58% patients indicated for coronary angioplasty on account of stable angina had a history of myocardial Q infarction, 93% had angina grade II or III according to CCS. Affection of one artery was diagnosed in 56% patients, complete revascularization was achieved in 59% of the operations. The clinical rate of success of catheterization was 97% in stenoses of the coronary arteries and 61% in coronary occlusions. In 57% of the treated lesions a coronary stent was implanted. Serious clinical complications developed in 1% of the interventions, none of the patients died. Catheterization treatment of stable angina is very successful and safe. PMID:11214365

  3. [Comparison of the results of coronary angioplasty and stenting during one year following surgery].

    PubMed

    Simonenko, V B; Seĭdov, V G; Zakharov, S V; Evsiukov, V V; Liubchuk, I V

    2007-01-01

    The purpose of the study was to compare long-term results of angioplasty and coronary arterial stenting (CAS) depending on the initial degree of coronary arterial (CA) lesion according to morphological stenosis classification, as well as to evaluate the influence of re-stenosis on myocardial contractility dynamics, anginal recurrence rate, and exercise tolerance. The subjects, 228 men after angioplasty and 184 men after CAS with wire stents without drug coating, were included in the study between 1989 and 2005. Coronarography was repeated in 358 patients one year after surgery. The patients were divided into two groups. The first group consisted of 161 patients, to who 180 stents were implanted. The second group consisted of 197patients, in who 226 angioplasty procedures were performed. Data were processed using standard variational statistical methods, i.e. the calculation of mean values and standard deviation. Statistical calculations were carried out using Analysis ToolPak- VBA software of Microsoft Excel 2000. The study found that one year after either intervention the number of patients without anginal symptoms fell significantly compared with this number during the in-hospital period. In group 2 the frequency of restenosis was higher and the number of patients with anginal symptoms was significantly bigger than in group 1; the number of asymptomatic patients was significantly bigger in group 1. Initial morphological characteristics of CA lesion had a significant effect on the long-term frequency of restenosis following endovascular treatment. Restenosis was 2 to 2.5 times more frequent in patients with C type CA lesion vs. patients with A type regardless the method of endovascular intervention. The results of the study demonstrate the importance of taking into account initial morphological characteristics of CA lesion; CAS is more preferable than angioplasty, especially in patients with C type CA lesion. PMID:17520881

  4. Safety and outcomes of day care based coronary angioplasty – First report from India

    PubMed Central

    Singh, Vivek Raj; Jayaraman, Balachander; Satheesh, Santhosh; Ananthakrishna Pillai, Ajith

    2015-01-01

    Background The concept of day care based coronary angioplasty might be frugal especially in countries like India where epidemic of coronary disease is enduring and healthcare delivery systems are limited. Published literature addressing the feasibility and safety of day care percutaneous coronary interventions (PCI) is lacking from our country. Objectives To study the safety and outcomes in stable cardiac patients undergoing day care coronary angioplasty. Methods A single centre nonrandomized active controlled trial of patients undergoing elective transradial coronary angioplasty and same day discharge after triaging was compared with a conventional arm of hospital overnight stay. Results Fifty six patients with stable coronary artery disease underwent day care angioplasty. There were no major immediate adverse cardiac and cerebral events noted in the first 24 h. The procedural result followed by a 6-h observation period allowed adequate triage of patients to same-day discharge or to extended clinical observation. Apart from one possible stent thrombosis on day 3 in the treatment arm where the patent received fibrinolytic treatment in a local hospital, there were no major adverse cardiac or cerebral vascular events in the study group. The six month clinical follow up in the day care procedure group was also unevenful for any major adverse cardiac events. Conclusion The study albeit small shows the feasibility and safety of day care PCI in the Indian scenario. It did not lead to additional complications compared with overnight stay. Triage of patients for an extended observation period can be performed adequately on the basis of clinical and procedural criteria. PMID:26071288

  5. Hugging balloons: coronary angioplasty of oversized vessels with side-by-side balloons.

    PubMed

    Teirstein, P S; Johnson, W L; Rutherford, B D; Hartzler, G O

    1988-01-01

    Angioplasty of large (greater than 4.0-mm) saphenous vein grafts using the largest available (4.0-mm) balloon catheters may result in inadequate graft dilatation. To avoid leaving a significant residual stenosis, two balloon catheters can be inflated side by side across the stenosis. Herein, we report two cases where this "hugging balloon" technique was used to achieve wide graft patency. PMID:2970301

  6. [Angioscopic evaluation of the immediate result of coronary angioplasty in relation to balloon inflation time].

    PubMed

    Eltchaninoff, H; Cribier, A; Koning, R; Jolly, N; Baala, B; Farid, N; Letac, B

    1994-06-01

    The aim of this study was to assess the effects of coronary angioplasty on the intima with respect to the duration of balloon inflation by percutaneous angioplasty. Twenty-seven patients were randomized according to the total duration of balloon inflation: Group I "standard" duration (total duration < or = 3 min, N = 13) and Group II: prolonged duration (total duration > or = 12 min, N = 14); the type and distribution of the lesions were comparable in the two groups. The results of angioplasty were evaluated immediately after dilatation by angiography and angioscopy. Angioscopy was performed without failure or complications with perfect definition of the images in all cases. Angioscopy showed 1) intimal tears, 2) thrombi, 3) longitudinal dissections. A classification in three grades was used taking the apparent gravity of the lesions into consideration. The mean duration of balloon inflation in Group I was 205 +/- 45 s and 958 +/- 129 s in Group II. The residual stenosis was 36 +/- 8% in Group I and 26 +/- 10% in Group II (p < 0.05). Angioscopy showed the frequency of intimal tears to be twice greater in Group I (9 cases) than in Group II (4 cases) (p = 0.05). Intravascular thrombi were observed in 13 cases, 6 in Group I and 7 in Group II. One case of longitudinal dissection was observed in each group: only one of these two cases was detected at angiography. The authors conclude that repeated and prolonged balloon inflations improve the immediate results of angioplasty with less residual stenosis at angiography and a lower incidence of intimal tears at angioscopy. PMID:7702414

  7. Remodelling of the Superior Caval Vein After Angioplasty in an Infant with Superior Caval Vein Syndrome

    SciTech Connect

    Mert, Murat Saltik, Levent; Gunay, Ilhan

    2004-08-15

    An 8-month old girl was presented with superior caval vein syndrome early after cardiac surgery. Angiography showed severe stenosis of the superior caval vein with 50 mmHg pressure gradient. Following balloon angioplasty, the pressure gradient was reduced to 7 mmHg with some residual stenosis of the superior caval vein. When the patient was reevaluated 5 months after the procedure, angiography revealed a normal diameter of the superior caval vein without a pressure gradient.

  8. Coronary Angioplasty and Cancer Risk: A Population-Based Cohort Study in Sweden

    SciTech Connect

    Lambe, M. Hall, P.; Granath, F.; Azodi, O. Sadr; Nilsson, T.

    2005-01-15

    Background. Percutaneous transluminal coronary angioplasty (PTCA) has become the reperfusion method of choice in patients with coronary artery disease. This sometimes complicated and lengthy procedure is performed using fluoroscopy and cineradiography or digital imaging, which may result in considerable exposure to ionizing radiation. Possible cancer risks in PTCA patients have been discussed, but never before examined in a population-based setting. Objective. To assess the cancer risks following PTCA. Methods. A cohort study was carried out based on nationwide registration of all coronary angioplasty procedures in Sweden between 1989 and 1998. The study encompassed a total of 23,097 PTCA patients followed up for cancer outcomes in the Swedish Cancer Register until December 31, 2000. The mean and median follow-up times were 4.8 and 4.5 years, respectively. The main outcome measures were standardized incidence ratios of cancer. Results. Except for a transient excess of lung cancers, observed number of cancers in patients who had undergone coronary angioplasty did not differ from those expected in the general population. If anything, the overall cancer risk was lower in the PTCA group (SIR 0.94; 95% CI 0.88-0.99). In particular, no increased risks were detected for leukemias or thyroid cancer. Conclusion. There was no indication of increased risks of leukemia or cancers overall in PTCA patients.

  9. Percutaneous trans-ulnar artery approach for coronary angiography and angioplasty; A case series study

    PubMed Central

    Roghani-Dehkordi, Farshad; Hadizadeh, Mahmood; Hadizadeh, Fatemeh

    2015-01-01

    BACKGROUND Coronary angiography is the gold standard method for diagnosis of coronary heart disease and usually performed by femoral approach that has several complications. To reduce these complications, upper extremity approach is increasingly used and is becoming preferred access site by many interventionists. Although radial approach is relatively well studied, safety, feasibility and risk of applying ulnar approach in not clearly known yet. METHODS We followed 97 patients (man = 56%, mean ± standard deviation of age = 57 ± 18) who had undergone coronary angiography or angioplasty via ulnar approach for 6-10 months and recorded their outcomes. RESULTS In 97 patients out of 105 ones (92.38%), procedure through ulnar access were successfully done. Unsuccessful puncture (3 patients), wiring (2 patients), passing of sheet (2 patients), and anatomically unsuitable ulnar artery (1 patient) were the reasons of failure. In 94 patients (89.52%), the angiography and angioplasty was done without any complications. Five patients (5.1%) hematoma and 11 patients (11%) experienced low-grade pain that resolved with painkiller. No infection, amputation or need for surgery was reported. CONCLUSION This study demonstrated that ulnar access in our patients was a safe and practical approach for coronary angiography or angioplasty, without any major complication. Bearing in mind its high success rate, it can be utilized when a radial artery is not useful for the catheterization and in cases such as prior harvesting of the radial artery (in prior coronary artery bypass grafting). PMID:26715936

  10. Influences on vascular wall smooth muscle cells with novel short-duration thermal angioplasty

    NASA Astrophysics Data System (ADS)

    Kunio, M.; Shimazaki, N.; Arai, T.; Sakurada, M.

    2012-02-01

    We investigated the influences on smooth muscle cells after our novel short-duration thermal angioplasty, Photo-thermo Dynamic Balloon Angioplasty (PTDBA), to reveal the mechanism that can suppress neo-intimal hyperplasia after PTDBA. We obtained the sufficient arterial dilatations by short-duration heating (<=15 s, <70°C) and low dilatation pressure (<0.4 MPa) without arterial injuries in our previous in vivo studies. Smooth muscle cells, which play most important role in chronic treatment effects, were heated during PTDBA and stretch-fixed after PTDBA. The dead cell rate by heating, estimated by Arrhenius equation with A=2.5x1016 s-1 and Ea=1.17×105 J mol-1, was 15.7+/-2.2% after PTDBA. The measured deformation rate of smooth muscle cells' nuclei was 1.6+/-0.1 after PTDBA in vivo. We found that the expression of smooth muscle cells' growth factor after PTDBA was inhibited 0.52 fold compared to that after the conventional balloon angioplasty in vivo. The measured neo-intimal hyperplasia occupancy rate was less than 20% after PTDBA in vivo. We prospect that the inhibition of the growth factor's expression by stretch-fixing may result to suppress the neo-intimal hyperplasia. In addition, the decrease of smooth muscle cells' density in the vessel media by heating might be another reason for the neo-intimal hyperplasia suppression.

  11. Percutaneous peripheral laser angioplasty with a pulsed Nd:YAG laser and sapphire tips

    NASA Astrophysics Data System (ADS)

    Kvasnicka, Jan; Stanek, Frantisek; Boudik, Frantisek; Kubecek, Vaclav; Krivanek, Jiri; Keclik, Richard; Prochazkova, Helena; Hamal, Karel

    1990-07-01

    Percutaneous transluminal laser angioplasty with a pulsed Nd:YAG laser (1,064 nm wavelength, 100 jig pulse duration, up to 0.4 J per pulse, 10 Hz repetition rate) coupled to optical fibers with sapphire tips of 1.8, 2.2 and 2.9 mm diameter was performed in 17 chronic occlusions of iliac, femoral, popliteal and fibular arteries in 15 patients. Clinically the procedure was successful in 14 cases. The probe formed a primary channel of at least 2.0 mm width which was further dilated by conventional balloon catheter. Ankle/brachial systolic pressure index (ABPI) increased from 0.46 0.13 to 0.84 0.21 after the procedure. Two failures were due to an extensive dissection which occurred after balloon angioplasty and resulted in an early reocclusion. In the remaining case a balloon catheter could not be introduced through the 30 cm long primary channel which reoccluded shortly after the recanalization. The initial patency rate was 82 % and in 5 patients followed for more then 6 months the ABPI showed only a minor decrease. These first results are encouraging and it is likely that this method could become an important alternative to conventional balloon angioplasty.

  12. Influence of a variant angina on the results of percutaneous transluminal coronary angioplasty.

    PubMed Central

    Leisch, F; Schützenberger, W; Kerschner, K; Herbinger, W

    1986-01-01

    Nineteen (86%) of 22 patients with variant angina and important coronary stenoses (greater than 60%) had successful percutaneous transluminal coronary angioplasty. The acute complications in two patients were not caused by coronary spasms but by dissection with disturbance of perfusion. One of these two patients required a coronary bypass graft; the other was treated conservatively. Myocardial infarction developed in both patients. Despite long term administration of nifedipine (30-80 mg daily), restenoses occurred within six months (on average after 10 weeks) in nine patients with symptoms and one without. In four patients the restenoses exceeded the degree of stenosis before angioplasty. Five patients were revascularised by surgical means. Vessels in three out of four patients were later successfully dilated. After a mean period of observation of 24 months (6-51 months) 18 of the 19 patients are symptom free and do not require medication. The results confirm that angioplasty is an effective method of treating patients with variant angina and important coronary stenoses. The problem of the high frequency of restenosis, however, remains unresolved. PMID:2945575

  13. Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting

    PubMed Central

    Liu, Jun-peng; Wang, Yin-zhou; Li, Yong-kun; Cheng, Qiong; Zheng, Zheng

    2015-01-01

    Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study investigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that restenosis occurred in 30% (3/10) of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% (2/17) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% (1/23) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically significant (P > 0.05). Experimental findings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervical and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis. PMID:26170826

  14. Combination of Rotational Atherothrombectomy and Paclitaxel-Coated Angioplasty for Femoropopliteal Occlusion

    PubMed Central

    Scheer, F; Lüdtke, CW; Kamusella, P; Wiggermann, P; Vieweg, H; Schlöricke, E; Lichtenberg, M; Andresen, R; Wissgott, C

    2014-01-01

    OBJECTIVE The rotational atherothrombectomy with Straub Rotarex® is a safe and efficient treatment of acute/subactute vascular occlusions. The purpose of this study was to evaluate the benefit of paclitaxel-coated angioplasty after rotational atherothrombectomy over an observation period of six months. MATERIALS AND METHODS Overall, 29 patients were treated with the Rotarex catheter in combination with paclitaxel-coated angioplasty. All patients had acute/subacute and chronic occlusions of the superficial femoral artery (SFA) and/or popliteal arteries. The ankle-brachial index (ABI) was detected before the intervention, after the procedure, and after six months. Also clinical examination and ultrasound scans were done in the observation period. RESULTS There were no technical failures. The ABI shows a significant increase from 0.52 ± 0.17 to 0.91 ± 0.25 in the follow-up. By ultrasound examination, there were found two (6.9%) restenoses during the follow-up. There was one dissection during the intervention (3.5%). CONCLUSION The rotational atherothrombectomy in combination with paclitaxel-coated angioplasty might be an effective and safe method with a promising low rate of restenosis at six months. PMID:25983558

  15. Detection of platelet deposition at the site of peripheral balloon angioplasty using indium-111 platelet scintigraphy

    SciTech Connect

    Pope, C.F.; Ezekowitz, M.D.; Smith, E.O.; Rapoport, S.; Glickman, M.; Sostman, H.D.; Zaret, B.L.

    1985-02-01

    Restenosis after balloon angioplasty may be mediated through platelet deposition at the site of arterial dilatation. The purpose of this study was to determine whether platelet deposition at the site of dilatation could be detected using indium-111 platelet scintigraphy. Fifteen patients, aged 60 +/- 9 years, with iliac or femoral (n . 12), renal artery (n . 2) or distal aortic (n . 1) stenoses were studied. All patients received intravenous heparin at the time of dilatation. Labeled platelets containing 471 +/- 65 muCi indium-111 were injected 0.25 to 4 hours after dilatation and 1 to 24 hours after imaging. In 11 of 12 patients with iliac and femoral dilatations, focal uptake was demonstrated at the angioplasty site. In 4 patients (2 patients with renal, 1 patient with iliofemoral, and 1 with distal aortic stenoses), uptake at the dilatation sites was not detected. This preliminary study indicates that despite intravenous heparin, platelets accumulate at sites of balloon dilatation. Platelet scintigraphy may be useful in predicting sites of future narrowing after angioplasty and may be used to test the efficacy of antiplatelet therapy in retarding restenosis.

  16. Predictive value of early maximal exercise test and thallium scintigraphy after successful percutaneous transluminal coronary angioplasty.

    PubMed Central

    Wijns, W; Serruys, P W; Simoons, M L; van den Brand, M; de Feijter, P J; Reiber, J H; Hugenholtz, P G

    1985-01-01

    Restenosis of the dilated vessel after percutaneous transluminal coronary angioplasty can be detected by non-invasive procedures but their ability to predict later restenosis soon after a successful angioplasty as well as recurrence of angina has not been assessed. A maximal exercise test and myocardial thallium perfusion scintigraphy were, therefore, performed in 91 asymptomatic patients a median of 5 weeks after they had undergone a technically successful angioplasty. Primary success of the procedure was confirmed by the decrease in percentage diameter stenosis from 64(12)% to 30(13)% as measured from the coronary angiograms and in the trans-stenotic pressure gradient (normalised for mean aortic pressure) from 0.61(0.16) to 0.17(0.09). A clinical follow up examination (8.6(4.9) months later) was carried out in all patients and a late coronary angiogram obtained in 77. The thallium perfusion scintigram showing the presence or absence of a reversible defect was highly predictive for restenosis whereas the exercise test was not. The positive predictive value of an abnormal scintigram was 82% compared with 60% for the exercise test (ST segment depression/or angina or both at peak workload). Angina or a new myocardial infarction occurred in 60% of patients with abnormal and in 21% of patients with normal scintigrams. PMID:3155619

  17. Subintimal angioplasty for superficial femoral artery occlusion: poor patency in critical ischaemia.

    PubMed Central

    Smith, B. M.; Stechman, M.; Gibson, M.; Torrie, E. P. H.; Magee, T. R.; Galland, R. B.

    2005-01-01

    INTRODUCTION: Subintimal angioplasty has been proposed for the treatment of long segment occlusive disease and for patients with critical limb ischaemia (CLI) with significant co-morbidity. There is no consensus as to short- and long-term patency. We present our experience with this technique. METHODS: Between 1995 and 2000, 43 consecutive patients (48 limbs) underwent subintimal angioplasty for superficial femoral artery occlusions. Outcome measures were haemodynamic and/or symptomatic patency. RESULTS: Technical success was achieved in 14/17 limbs with CLI (82%) and 30/31 (97%) with intermittent claudication (IC). There were 7 complications (15%), 6 occurring in the claudicant group. The median occlusion length was 10 cm for CLI and 6 cm for IC. Patency at 12 and 36 months, on an intention-to-treat basis, was 69% and 58% for claudicants and 25% and 25% for patients with CLI (P = 0.0005 and P = 0.0044, respectively). Following only technically successful procedures, 12-month patency was 72% (IC) and 31% (CLI) (P = 0.009). Patients with occlusions > or = 10 cm were more likely to re-occlude than those < 10 cm (12-month patency 60% versus 25%;P = 0.037). CONCLUSIONS: In this series, short- and long-term patency in patients with CLI is poor. Subintimal angioplasty in the treatment of CLI should be reserved for those patients not fit for surgical bypass. PMID:16176697

  18. +Ophitoxaemia and myocardial infarction--the issues during primary angioplasty: a review.

    PubMed

    Gupta, Prabha Nini; Thomas, Jinesh; Francis, Preetham Kumar; Shylaja, Sajith Vamadevan

    2014-01-01

    'The Big four' are the most poisonous snakes in India, and especially in Kerala. These include the cobra, the viper, the krait and the sea snake. Most of the poisonous snakebites in India occur in Kerala. We believe there are only a few reports of myocardial infarction after snakebites and most of these are viper bites. We believe this is the second case of primary angioplasty for a snakebite. There are at least a few potential issues in performing a primary angioplasty in a snakebite case, namely (1) Is it a thrombus or a spasm? (2) Are the bleeding parameters deranged? Will the patient tolerate tirofiban and other glycoprotein (GB) 2b3a inhibitors? Will he develop dangerous bleeding due to the high dose of heparin needed? Further, would we save the patient from myocardial infarction only to lose him to renal failure, both due to the nephrotoxicity of the venom, the kidney being further damaged by the contrast media used for the angioplasty? We discuss all these issues as they crossed our mind, and hope it will help further treatment in others. We would like to review the available literature on these points and describe a recent case of ours. PMID:25342187

  19. Suppression of Neointimal Hyperplasia Following Angioplasty-Induced Vascular Injury in Pigs Infected with Swinepox Virus

    PubMed Central

    Shimamura, Takeshi; Jeng, David; Lucas, Alexandra; Essani, Karim

    2012-01-01

    Many patients suffering from angina pectoris are treated with percutaneous coronary intervention (PCI) and quickly develop angiographic renarrowing, or restenosis, at the site of PCI treatment. Restenosis is thought to arise from the combinatorial activation of thrombotic and inflammatory responses. The inflammatory response responsible for restenosis is also thought to involve the activation of a cascade of serine proteases and its subsequent regulation. Poxviruses are known to possess a variety of immunomodulatory strategies, some of which target serine proteases, cytokines, and chemokines. To this end we evaluated whether systemic species-specific swinepox virus (SPV) infection could induce sufficient host-immune modulation to promote an anti-inflammatory and anti-proliferative effect, thereby preventing restenosis. Two groups of domestic feeder pigs were used - the first group was experimentally infected with SPV (n= 11) and the second group served as an uninfected control (n= 5). A week after infection, the pigs were anesthetized and percutaneous transluminal coronary angioplasty (PTCA) was performed in the left anterior descending coronary artery using X-ray fluoroscopy to visualize the balloon and record angiograms. Three weeks post infection, the pigs were euthanized and balloon angioplasty injured arteries were harvested and examined. We observed a statistically significant reduction of restenosis in SPV-infected pigs (p = 0.05) compared to control pigs and conclude that systemic swinepox virus infection causes sufficient host immune suppression to significantly reduce restenosis in pigs after balloon angioplasty injury. PMID:23136622

  20. Rotational atherectomy or balloon angioplasty in the treatment of intra-stent restenosis: BARASTER multicenter registry.

    PubMed

    Goldberg, S L; Berger, P; Cohen, D J; Shawl, F; Buchbinder, M; Fortuna, R; O'Neill, W; Leon, M; Braden, G A; Teirstein, P S; Reisman, M; Bailey, S R; Dauerman, H L; Bowers, T; Mehran, R; Colombo, A

    2000-12-01

    The BARASTER registry was formed to evaluate the initial success and long-term results of rotational atherectomy in the management of in-stent restenosis. Rotational atherectomy was used in 197 cases of in-stent restenosis: 46 with stand-alone rotational atherectomy or at most 1 atmosphere of balloon inflation (Rota strategy), and 151 with rotational atherectomy and adjunctive balloon angioplasty <1 atmosphere (Combination strategy). These were compared with 107 episodes of in-stent restenosis treated with balloon angioplasty alone. In this observational study, the use of Combination therapy was associated with a slightly higher initial success rate (95% vs. 87% with the Rota strategy and 89% with Balloons, P = 0.08). There was a reduction in one year clinical outcomes (death, myocardial infarction or target lesion revascularization) in the combination group (38% vs. 60% with Rota and 52% with balloons, P = 0.02). These data support a benefit of the strategy of debulking with rotational atherectomy followed by adjunctive balloon angioplasty, in the management of in-stent restenosis. PMID:11108670

  1. ...und Einstein hatte doch recht

    NASA Astrophysics Data System (ADS)

    Will, Clifford M.; Leuchs, Anne; Leuchs, Gerd

    Keine wissenschaftliche Theorie ist auf solche Faszination auch außerhalb der Wissenschaft gestoßen wie die Allgemeine Relativitätstheorie von Albert Einstein, und keine wurde so nachdrücklich mit den Mitteln der modernen Physik überprüft. Wie hat sie diesen Test mit Raumsonden, Radioastronomie, Atomuhren und Supercomputern standgehalten? Hatte Einstein recht? Mit der Autorität des Fachmanns und dem Flair des unvoreingenommenen Erzählers schildert Clifford Will die Menschen, Ideen und Maschinen hinter den Tests der allgemeinen Relativitätstheorie. Ohne Formeln und Fachjargon wird der leser mit Einsteins Gedanken vertraut und erfährt von der Bestätigung seiner Vorhersagen, angefangen bei der Lichtablenkung im Schwerefeld der Sonne 1919 bis zu den ausgefeilten Kreiselexperimenten auf dem Space Shuttle. Die Allgemeine Relativitätstheorie hat nich nur alle diese Tests bestanden, sie hat darüber hinaus wesentlich beigetragen zu unserem Verständnis von Phänomenen wie Pulsaren, Quasaren, Schwarzen Löchern und Gravitationslinsen. Dieses Buch erzählt lebendig und spannend die Geschichte einer der größten geistigen Leistungen unserer Zeit.

  2. Pyropheophorbide und a as a catabolite of ethylene-induced chlorophyll und a degradation

    SciTech Connect

    Shimokawa, Keishi; Hashizume, Akihito ); Shioi, Yuzo )

    1990-05-01

    An enzyme extract prepared from ethylene-induced degreening Citrus fruits contains chlorophyll (Chl) degrading enzymes. The fate of Chl carbons during an enzymatic degradation was investigated using Chl {und a}-{sup 14}C. Accompanying the disappearance of labelled Chl {und a}, pheophorbide {und a} and pyropheophorbide {und a} appeared and accumulation of pyropheophorbide {und a} was observed. HydroxyChl {und a} was also detected, but this is thought to be an artifact during chromatography. Unlike ethylene-induced Citrus fruits (in vivo), further degradation of pyropheophorbide {und a} did not occur in vitro enzyme system. This suggests that there is a lack of enzyme(s) and/or cofactor(s) for further degradation. It is concluded that Chl {und a} degraded enzymatically by the following order: Chl {und a}, chlorophyllide {und a}, pheophorbide {und a} and pyropheophorbide {und a}.

  3. Beschallungstechnik, Beschallungsplanung und Simulation

    NASA Astrophysics Data System (ADS)

    Ahnert, Wolfgang; Goertz, Anselm

    Die primäre Aufgabe einer Lautsprecheranlage ist es, Musik, Sprache oder auch Signaltöne und Geräusche wiederzugeben. Diese können von einem Tonträger kommen (CD, Sprachspeicher), von einem anderen Ort übertragen (Zuspielung über Radio, TV, Telefon) oder vor Ort erzeugt werden. Letzteres umfasst Konzerte, Ansprachen, Durchsagen oder künstlerische Darbietungen, bei denen es meist darum geht, eine bereits vorhandene Quelle einer größeren oder weiter verteilten Anzahl von Personen zugänglich zu machen.

  4. Treatment of the Budd-Chiari syndrome in polycythemia vera by repeated percutaneous transluminal angioplasty of a hepatic vein stenosis

    PubMed Central

    Nishikawa, M.; Miyoshi, S.; Imai, Y.; Tarui, S.; Seki, K.; Minami, Y.; Kawata, S.; Nakamura, H.

    1982-01-01

    This report is of a 63-year-old man with polycythemia vera who developed the Budd-Chiari syndrome due to right hepatic vein stenosis. Diagnosis was made by laparoscopy and liver biopsy, and confirmed by hepatic venography. The patient was treated by percutaneous transluminal angioplasty, and recovered completely from ascites, leg oedema and venous stasis. No pulmonary embolism was observed. One month after angioplasty, a second laparoscopy and liver biopsy showed a marked improvement in hepatic congestion and haemorrhagic necrosis, thereby confirming the effectiveness of this technique in treating the Budd-Chiari syndrome. Further treatments with percutaneous transluminal angioplasty were required with a good clinical outcome. ImagesFig. 1Fig. 2Fig. 4 PMID:6215641

  5. Comparison of activation process of platelets and neutrophils after coronary stent implantation versus balloon angioplasty for stable angina pectoris.

    PubMed

    Inoue, T; Sohma, R; Miyazaki, T; Iwasaki, Y; Yaguchi, I; Morooka, S

    2000-11-15

    The pathophysiologic features of stent-induced cellular responses of platelets and leukocytes have not been established. This study was designed to clinically investigate the activation of platelets and neutrophils after coronary stenting and to identify its effects on the long-term results of coronary stents. Forty-eight consecutive patients with left anterior descending coronary artery disease indicating coronary intervention were randomly assigned to either a balloon angioplasty group or a coronary stent group. Flow cytometric analysis demonstrated that the transcardiac gradient (the value of coronary sinus blood minus the value of peripheral blood) of platelet surface expression of CD62P (p < 0.001) and CD63 (p < 0.01) increased immediately after coronary stenting, but increased less significantly immediately after balloon angioplasty (CD62P, p < 0.01; CD63, p < 0.05). These increases were persistently observed after coronary stenting but transiently after balloon angioplasty alone during a 48-hour observation period after the procedures. The gradient for neutrophil surface expression of CD11b increased, and that of CD62 L decreased 48 hours after coronary stenting (CD11b, p < 0.001; CD62 L, p < 0.05), but these changes showed less significance 48 hours after balloon angioplasty alone (CD11b, p < 0.05; CD62 L, p = NS). The gradients 48 hours after the procedures for both CD62P (r = 0.39, p < 0.05) and CD11b (r = 0.44, p < 0.01) were independently correlated with the late loss in the stent group, whereas the correlation was seen only for CD11b (r = 0.38, p < 0.05) in the balloon angioplasty group. Both platelet and neutrophil activation was greater after coronary stenting than after balloon angioplasty. Cellular interactions between platelets and neutrophils may be related to the progression of neointimal proliferation leading to restenosis after coronary stent implantation. PMID:11074199

  6. Percutaneous peripheral excimer laser angioplasty: immediate success rate and short-term outcome

    NASA Astrophysics Data System (ADS)

    Visona, Adriana; Liessi, Guido; Bonanome, Andrea; Lusiani, Luigi; Miserocchi, Luigi; Pagnan, Antonio

    1991-05-01

    Excimer Laser Angioplasty was attempted in 47 patients (36 males, 11 females, mean age 62+/- 7 years, range 39-77 years), affected by peripheral vascular disease. Thirty-seven patients had a total occlusion of the superficial femoral artery, 3 of the iliac artery and 1 of the popliteal artery; 6 patients showed a subocclusive stenosis of the superficial femoral artery. Occlusions and subocclusive stenoses were classified by length: < 10 cm (28 cases), > 10 cm (19 cases). A commercial excimer laser (Technolas Max-10) was used at the Xenon- Chloride wavelength of 308 nm. The laser operated at 60 ns pulse length and at 20-40 Hz repetition rate. Applied energy fluence was 20 mJ/pulse. The energy was delivered through a multifiber catheter, which combines 12 (7F) or 18 (9F) fibers (260 micron diameter each), concentrically arranged. Balloon dilatation was associated to complete the procedure in 38 cases. The treated arteries were successfully recanalized in 41 out of 47 patients (87%). Hemodynamic improvement was confirmed by a significant increase of ankle/brachial systolic pressure index (from 0.60+/- 0.17 to 0.79+/- 0.20, p < 0.005). Failure to recanalize arterial occlusion occurred in 6 cases, and was due to dissection in 3 patients and inability to cross the final segment of a long occlusion in 3 patients. The success rate was higher for lesions < 10 cm in length. Early reocclusion was observed in 7 patients and was associated with poor run-off. The cumulative patency rate at 1 month was 90.7%. Preliminary results are encouraging. More suitable catheters and better selection of patients should improve the efficacy of laser angioplasty and should allow to perform laser procedures without combining balloon angioplasty.

  7. Early results of pulsed dye laser angioplasty with integral ball-tips in long femoral occlusions

    NASA Astrophysics Data System (ADS)

    Murray, Alan; Mitchell, David C.; Wood, Richard F. M.

    1990-07-01

    A Pulsed Dye laser together with specifically designed integral ball-tipped optical fibres have been used for the primary recanalisation of femoropopliteal vascular disease in 25 limbs of 23 patients. All patients had complete occlusions of the vessels ranging from 8-49cms in length (mean 22cms), having presented with critical ischaemia (18) or severe claudication warranting operative intervention (5). Pedal ulceration was present in 8 limbs and digital gangrene in 4. The laser produced visible light at 480nm in lOOmJ/lus pulses, at a frequency of 10-20Hz. The energy delivery device comprised a smooth atraumatic ball-tip constructed from the glass of the optical fibre, which was loaded retrogradely into a standard balloon angioplasty catheter. The device was introduced through a common femoral artery cutdown. Angiographic recanalisation was achieved in 22 of the 25 limbs with a mean energy of 280J(range 68-727J) and in each case the channel created by the laser fibre was augmented by balloon angioplasty. Technical failure occurred in three cases, caused by a wall dissection, persistent side-branch entry and incomplete lesion penetration respectively. Eighteen of procedures (72%) were clinically successful with marked symptomatic improvement. Of the four angiographic successful but clinical failures, acute occlusion within 48 hours occurred in 2 diabetic patients with very poor run-off and distal gangrene. The third case failed acutely due to a technically inadequate balloon dilatation and the fourth patient failed to improve symptomatically due to widespread with segmental tibial vessel disease below a successful recanalisation. Over a mean follow-up period of 7 months, three patients died of myocardial infarction. Twelve of the 23 patients (52%) remain well with patent vessels. These early results demonstrate the efficacy of pulsed dye laser angioplasty using ball-tipped optical fibres.

  8. Cardiac release of chemoattractants after ischaemia induced by coronary balloon angioplasty.

    PubMed Central

    Neumann, F J; Richardt, G; Schneider, M; Ott, I; Haupt, H M; Tillmanns, H; Schömig, A; Rauch, B

    1993-01-01

    OBJECTIVE--To investigate the release of chemoattractants after myocardial ischaemia during balloon angioplasty. DESIGN--Sampling of femoral arterial and coronary sinus blood before and immediately after the first balloon inflation during angioplasty. In a study group of 16 patients the balloon was kept expanded for two minutes, whereas in a control group of eight patients the first balloon inflation was brief (< 10 s). MAIN OUTCOME MEASURES--Chemotaxis of neutrophils from healthy donors towards patient plasma (Boyden chamber), superoxide anion production by normal neutrophils after incubation with patient plasma (cytochrome C reduction). RESULTS--In the study group, coronary sinus plasma after balloon deflation was more chemoattractive to normal neutrophils (median relative increase 24% (quartiles: 4%, 45%), p = 0.008) and induced a higher superoxide anion production in normal neutrophils (44% (10%, 97%), p = 0.013) than arterial plasma. Concomitantly, the degree of activation of patient neutrophils was increased in coronary sinus blood compared with arterial blood, as shown by an increased proportion of neutrophils reducing nitro-blue tetrazolium (21% (9%, 38%), p = 0.006) and a decreased neutrophil filter-ability (-16%(-3%, -40%), p = 0.003) in coronary sinus blood. In the study group before balloon inflation and in the control group before and after balloon inflation differences between arterial and coronary sinus blood were not significant. Signs of ischaemia (lactate release, ST segment changes) were only detected in the study group. CONCLUSION--After transient myocardial ischaemia during balloon angioplasty there is a local release of chemoattractants, associated with neutrophil activation. PMID:8037995

  9. Preclinical Feasibility of a Technology Framework for MRI-guided Iliac Angioplasty

    PubMed Central

    Rube, Martin A.; Fernandez-Gutierrez, Fabiola; Cox, Benjamin F.; Holbrook, Andrew B.; Houston, J. Graeme; White, Richard D.; McLeod, Helen; Fatahi, Mahsa; Melzer, Andreas

    2015-01-01

    Purpose Interventional MRI has significant potential for image guidance of iliac angioplasty and related vascular procedures. A technology framework with in-room image display, control, communication and MRI-guided intervention techniques was designed and tested for its potential to provide safe, fast and efficient MRI-guided angioplasty of the iliac arteries. Methods A 1.5T MRI scanner was adapted for interactive imaging during endovascular procedures using new or modified interventional devices such as guidewires and catheters. A perfused vascular phantom was used for testing. Pre-, intra- and post-procedural visualization and measurement of vascular morphology and flow was implemented. A detailed analysis of X-Ray fluoroscopic angiography workflow was conducted and applied. Two interventional radiologists and one physician in training performed 39 procedures. All procedures were timed and analyzed. Results MRI-guided iliac angioplasty procedures were successfully performed with progressive adaptation of techniques and workflow. The workflow, setup and protocol enabled a reduction in table time for a dedicated MRI-guided procedure to 6 min 33 s with a mean procedure time of 9 min 2 s, comparable to the mean procedure time of 8 min 42 s for the standard X-Ray guided procedure. Conclusions MRI-guided iliac vascular interventions were found to be feasible and practical using this framework and optimized workflow. In particular the real-time flow analysis was found to be helpful for pre- and post-interventional assessments. Design optimization of the catheters and in vivo experiments are required before clinical evaluation. PMID:25102933

  10. Experimental analysis of sapphire contact probes for Nd-YAG laser angioplasty.

    PubMed

    Ashley, S; Brooks, S G; Gehani, A A; Kester, R C; Rees, M R

    1990-06-01

    Laser angioplasty may offer percutaneous recanalization of occluded vessels where conventional guidewire and balloon techniques fail. Metal laser thermal angioplasty probes may, however, cause excessive thermal damage due to high tip temperatures (greater than 400.C). Therefore, contact probes made from artificial sapphire crystal designed for general laser surgery are currently being evaluated for use in laser angioplasty with continuous wave Nd-YAG energy. The sapphire modifies the laser energy in various ways, and this paper examines the physical characteristics of five types of rounded sapphire probe (SMTR, MTR, MTRL, OS, LT) and how these properties are affected by clinical usage. The laser beam profile emitted by these probes demonstrates a focal spot 1-2 mm in front of the tip. However, the forward transmission of Nd-YAG energy through the sapphires varied (SMTR, 85%; MTR, 83%; MTRL, 75%; OS, 54%; LT, 69%). Probe heating occurs owing to energy absorption within the sapphire. The surface temperature of the sapphires was measured in air by infrared thermography and the hottest region within the probes localized by an isothermographic technique. At energy settings used clinically (20 J, 10 watts for 2 s) the SMTR, MTR, and MTRL probes exhibited higher temperature rises (94-112.C) than the OS and LT probes (30.C), and heating was localized to the front surface of the former probes. Peak sapphire temperatures remained lower than those of metal probes even at higher energies. After clinical use, the MTR probe demonstrated reduced transmission, beam defocusing, and increased heating, due to surface pitting. Thus, recanalization with sapphire probes occurs by a combination of photothermal and contact thermal effects that are localized to the probe tip and may reduce the degree of thermal injury associated with metal probes. Understanding these basic properties is important to the application and development of contact probes for laser recanalization. PMID:2142867

  11. [Correction of dyslipidemia in patients with arteriosclerosis obliterans as a method for improving the results of endovascular angioplasty].

    PubMed

    Petukhov, V A; Seitmykhamedov, M D; Dibirov, A D; Dubovik, S G; Sergeeva, N A; Prokubovskiĭ, V I

    1992-01-01

    The authors analyse the results of endovascular angioplasty of the pelvic and lower limb arteries in 147 patients of various age suffering from arteriosclerosis obliterans. It was found that the results of endovascular angioplasty depended on the state of the lipid balance. The necessity for correcting the shifts in the lipid metabolism is shown. The article evaluates the results of dyslipidemia correction by dietotherapy, pharmacotherapy, and operation for partial ilio-shunting in patients with arteriosclerosis obliterans of the pelvic and lower limb arteries. The efficacy of the listed methods of treatment are analysed according to the severity of dyslipidemia. PMID:1457133

  12. Spontaneous Recanalization of Superior Mesenteric Artery Occlusion Following Angioplasty and Stenting of Inferior Mesenteric Artery

    SciTech Connect

    Akpinar, Erhan Cil, Barbaros E.; Arat, Anil; Baykal, Atac; Karaman, Kerem; Balkanci, Ferhun

    2006-02-15

    An 84-year-old woman with a history of hypertension and coronary artery disease was admitted with a progressively worsening diffuse abdominal pain. Computed tomography scan of the abdomen and angiography revealed occlusion of the origin and proximal portion of superior mesenteric artery. Aortography also showed severe origin stenosis of inferior mesenteric artery and that the distal part of the superior mesenteric artery was supplied by a prominent marginal artery of Drummond. Patient was effectively treated with percutaneous transluminal angioplasty and stenting of the inferior mesenteric artery. Follow-up imaging studies demonstrated patency of the stent and spontaneous recanalization of superior mesenteric artery occlusion.

  13. Early and Long-Term Results of Subclavian Angioplasty in Aortoarteritis (Takayasu Disease): Comparison with Atherosclerosis

    SciTech Connect

    Tyagi, Sanjay; Verma, Puneet K.; Gambhir, Daljeet S.; Kaul, Upkar A.; Saha, Renuka; Arora, Ramesh

    1998-05-15

    Purpose: To compare the early andlong-term outcomes of subclavian artery angioplasty in patients with aortoarteritis and atherosclerosis. Methods: Sixty-one subclavian artery angioplasties were performed in 55 consecutive patients with aortoarteritis (n= 32) and atherosclerosis (n= 23) between 1986 and 1995. An arch aortogram followed by a selective subclavian artery angiogram was done to profile the site and extent of the lesion, its relation to the vertebral artery, and the distal circulation. Percutaneous transluminal angioplasty (PTA) was performed via the femoral route for 56 stenotic lesions and 5 total occlusions. Results: PTA was successful in 52 (92.8%) stenotic lesions and 3 (60%) total occlusions. Three patients (5.4%) had complications, that could be effectively managed nonsurgically. Compared with atherosclerosis, patients with aortoarteritis were younger (27.4 {+-} 9.3 years vs 54.5 {+-} 10.5 years; p < 0.001), more often female (75% vs 17.4%; p < 0.001), gangrene was uncommon (0% vs 17.4%; p < 0.05), and diffuse involvement was seen more often (43.8% vs 4.4%; p < 0.001). The luminal diameter stenoses were similar before PTA (88.6 {+-} 9.7% vs 89.0 {+-} 9.1%; p= NS). Higher balloon inflation pressure was required to dilate the lesions of aortoarteritis (9.9 {+-} 4.6 ATM vs 5.5 {+-} 1.0 ATM; p < 0.001). This group had more residual stenosis (15.5 {+-} 12.4% vs 8.3 {+-} 9.4%; p < 0.05) after PTA. There were no neurological sequelae, even in PTA of prevertebral lesions. On 3-120 months (mean 43.3 {+-} 28.9 months) follow-up of 40 patients, restenosis was more often observed in patients with aortoarteritis, particularly in those with diffuse arterial narrowing. These lesions could be effectively redilated. Clinical symptoms showed marked improvement after successful angioplasty. Conclusion: Subclavian PTA is safe and can be performed as effectively in aortoarteritis as in atherosclerosis, with good long-term results. Long-term follow-up shows that it

  14. Failure and Success of Percutaneous Angioplasty in a Hypertensive Child with Bilateral Renal Artery Stenosis

    SciTech Connect

    Giavroglou, Constantinos; Tsifountoudis, Ioannis; Boutzetis, Theodoros; Kiskinis, Dimitrios

    2009-01-15

    We describe the clinical course of a 5-year-old girl with severe arterial hypertension that was uncontrollable with antihypertensive medication. Renal angiography revealed bilateral renal artery stenoses. Because percutaneous transluminal renal angioplasty (PTRA) failed to dilate the stenotic lesions, a renal artery bypass grafting in both renal arteries was performed. The patient remained normotensive for 7 months, and after that the arterial pressure increased again. Digital subtraction angiography demonstrated stenosis at the peripheral and central anastomosis of the vein graft that was used for revascularization of the left kidney. PTRA was decided on and successful patency was achieved. The patient has now been normotensive for a period of 5 years.

  15. Renaturierung und Management von Heiden

    NASA Astrophysics Data System (ADS)

    Härdtle, Werner; Assmann, Thorsten; van Diggelen, Rudy; von Oheimb, Goddert

    Heiden zählen zu den ältesten und besonders reizvollen Kulturlandschaften Nordwesteuropas. Sie sind bezeichnend für nährstoffarme Böden in wintermilden Gebieten mit hohen Sommerniederschlägen. Während Heiden vor wenigen Jahrhunderten noch weit verbreitet und für manche Landschaften sogar prägend waren, hat sich ihr Areal heute auf wenige, meist in Naturschutzgebieten gelegene Restbestände verkleinert. Zu diesem Rückgang haben maßgeblich Änderungen der Landnutzung, aber auch Nährstoffeinträge aus umgebenden Agrarflächen und atmogene Depositionen beigetragen. In den meisten Ländern der Europäischen Union sind Heiden heute gesetzlich geschützte Ökosysteme, da diese, neben ihrem Erholungswert für den Menschen, Pflanzen- und Tierarten beherbergen, die außerhalb von Heiden nicht oder kaum überlebensfähig sind.

  16. Comparison of left ventricular ejection fraction and inducible ventricular tachycardia in ST-elevation myocardial infarction treated by primary angioplasty versus thrombolysis.

    PubMed

    Chong, James J H; Ganesan, Anand N; Eipper, Vicki; Kovoor, Pramesh

    2008-01-15

    Electrophysiologic studies predict the risk for sudden death after myocardial infarction (MI). Although primary angioplasty has become the preferred method of treatment for ST-elevation MI, intravenous thrombolysis remains the first-line treatment in 30% to 70% of cases worldwide. Rates of ventricular tachyarrhythmias may vary according to type of reperfusion treatment. This study was undertaken to examine the hypothesis that the left ventricular ejection fraction (LVEF) and rates of inducible ventricular tachycardia may be more favorable in treatment with primary angioplasty rather than thrombolysis. Consecutive patients receiving primary angioplasty (n = 225) or thrombolysis (n = 195) for ST-elevation MI were included. The mean LVEF was 48 +/- 12% for the primary angioplasty group and 46 +/- 13% for the thrombolysis group (p = 0.30). The proportion of patients with LVEFs <40% was 30% in the primary angioplasty group and 30% in the thrombolysis group (p = 0.98). Patients with LVEFs <40% underwent electrophysiologic studies. Ventricular tachycardia was inducible in 23 of 66 primary angioplasty patients (34.8%) compared with 21 of 55 (38.1%) thrombolysis patients (p = 0.69). Implantable cardiac defibrillators were inserted in 30 patients, of whom 8 (27%) had appropriate device activations. The mean time from MI to first spontaneous activation was 387 +/- 458 days. In conclusion, patients treated with thrombolysis or primary angioplasty for ST-elevation MIs had similar resultant LVEFs and rates of inducible ventricular tachycardia. There was a surprisingly high rate of spontaneous defibrillator activations, often occurring late after MI. PMID:18178398

  17. Fiberoptic study on the effects of transluminal angioplasty in experimental occlusive arterial thrombosis.

    PubMed

    Tomaru, T; Uchida, Y; Sugimoto, T

    1988-02-01

    Percutaneous transluminal coronary angioplasty has been proposed as definitive therapy for coronary recanalization of occluded coronary arteries in patients with acute myocardial infarction (AMI). The effects of transluminal angioplasty (TA) on experimental occlusive canine arterial thrombi that closely simulated the clinical condition was examined by a fiberoptic method. Experimental arterial thrombosis was produced by endothelial denudation and induction of luminal stenosis. Eighteen dogs that showed total occlusion of the iliac artery with thrombi were evaluated. Seven dogs (group A) with 6-hour-old thrombi received 20,000 IU/kg intravenous urokinase (UK) but did not show recanalization. TA was performed with a Gruentzig or Simpson-Robert balloon catheter and its effect was evaluated by a vascular fibroscope. Eight dogs (group B) with 6-hour-old thrombi underwent primary TA. After TA, less than 50% luminal obstruction with residual thrombi was visualized in five dogs (71%) of group A and four dogs (50%) of group B. Residual thrombi showed a doughnut-like or globular type shape and consisted of dense fibrin networks and compact platelet aggregates. All dogs in group B received 20,000 IU/kg intravenous UK after TA, but most of them showed progression of thrombus size despite UK infusion. In conclusion, the results suggest (1) that TA is effective in recanalization of an occluded artery with aged thrombus that is resistant to thrombolytic therapy and (2) that vascular fiberscope is a useful method for evaluation of the effects of TA on occlusive arterial thrombus. PMID:2963513

  18. Experience of Staged Angioplasty to Avoid Hyperperfusion Syndrome for Carotid Artery Stenosis

    PubMed Central

    UCHIDA, Kazutaka; YOSHIMURA, Shinichi; SHIRAKAWA, Manabu; SHINDO, Seigo; EGASHIRA, Yusuke; IWAMA, Toru; YAMADA, Kiyofumi

    2015-01-01

    Hyperperfusion syndrome (HPS) after carotid artery stenting (CAS) may cause hemorrhagic or ischemic events leading to serious sequelae. We previously reported the staged angioplasty (SAP) to prevent HPS. In the present study, we analyzed our treatment results of SAP to know its effectiveness and problems. The study included 43 patients scheduled for SAP in whom preoperative single photon emission computed tomography (SPECT) showed severely impaired cerebral blood flow (CBF). The analyzed subjects were 38 males and 4 females, mean age was 73 ± 8.5 years old. SAP was indicated for the patients whose CBF ratio in the affected/unaffected hemisphere (asymmetry index) was below 0.8, and cerebrovascular reactivity measured by acetazolamide challenge was below 10%. First, percutaneous transluminal angioplasty (PTA) was performed. If PTA was successful, CAS was performed 2 weeks later. If PTA was not successful due to inadequate dilatation or extensive dissection, a stent was placed. SPECT was performed immediately after PTA and CAS to confirm the presence or absence of hyperperfusion phenomenon (HPP) indicating radiologic hyperperfusion. In 39 of 43 patients (91%), SAP was successfully performed and HPP was not observed. On the other hand, in the other four patients (9%), immediate stent placement was added due to inadequate dilatations in three patients and vascular dissection in one. Among 43 candidates for SAP, 41 patients (95.4%) had favorable course, but one hemorrhagic and one ischemic complications were observed after PTA. SAP was a relatively simple procedure, and its clinical results seemed acceptable. PMID:26447098

  19. Interleukin-6 and asymmetric dimethylarginine are associated with platelet activation after percutaneous angioplasty with stent implantation.

    PubMed

    Gremmel, Thomas; Perkmann, Thomas; Kopp, Christoph W; Seidinger, Daniela; Eichelberger, Beate; Koppensteiner, Renate; Steiner, Sabine; Panzer, Simon

    2015-01-01

    Data linking in vivo platelet activation with inflammation and cardiovascular risk factors are scarce. Moreover, the interrelation between endothelial dysfunction as early marker of atherosclerosis and platelet activation has not been studied, so far. We therefore sought to investigate the associations of inflammation, endothelial dysfunction and cardiovascular risk factors with platelet activation and monocyte-platelet aggregate (MPA) formation in 330 patients undergoing angioplasty with stent implantation for atherosclerotic cardiovascular disease. P-selectin expression, activation of glycoprotein IIb/IIIa and MPA formation were determined by flow cytometry. Interleukin (IL)-6, high sensitivity C-reactive protein and asymmetric dimethylarginine (ADMA) were measured by commercially available assays. IL-6 was the only parameter which was independently associated with platelet P-selectin expression and activated GPIIb/IIIa as well as with leukocyte-platelet interaction in multivariate regression analysis (all p<0.05). ADMA was independently associated with GPIIb/IIIa activation (p<0.05). Patients with high IL-6 exhibited a significantly higher expression of P-selectin than patients with low IL-6 (p=0.001), whereas patients with high ADMA levels showed a more pronounced activation of GPIIb/IIIa than patients with low ADMA (p=0.003). In conclusion, IL-6 and ADMA are associated with platelet activation after percutaneous angioplasty with stent implantation. It remains to be established whether they act prothrombotic and atherogenic themselves or are just surrogate markers for atherosclerosis with concomitant platelet activation. PMID:25807315

  20. Differential glomerular filtration rate in diagnosis of renovascular hypertension and follow-up of balloon angioplasty

    SciTech Connect

    Lamki, L.; Spence, J.D.; MacDonald, A.C.; Roulston, M.

    1986-03-01

    Two hundred nine hypertensive patients with high stimulated plasma renin levels were screened for renovascular hypertension using Tc-99m DTPA renal scintigraphy. Differential glomerular filtration rate (Diff-GFR) was obtained by integrating the area under the background-subtracted renogram of each kidney between 1 and 3 minutes. 50 patients who also had undergone selective renal angiography were divided into four groups according to Diff-GFR contribution by one of the kidneys. If one kidney contributed 45-50% of total GFR, this was regarded as normal. A Diff-GFR of less than 45% was very considered to be very suggestive of renovascular hypertension in the appropriate clinical setting, while a Diff-GFR of less than 20% indicated that the renal artery might not be amenable to successful balloon angioplasty. Diff-GFR following balloon angioplasty closely reflected the early clinical response of the patients--and in some cases progressive Diff-GFR improvement was observed several months later. Diff-GFR as a scintigraphic criterion for renovascular hypertension has a sensitivity of 93%, specificity of 74%, and accuracy of 85%.

  1. British Society of Interventional Radiology Iliac Artery Angioplasty-Stent Registry III

    SciTech Connect

    Uberoi, Raman Milburn, Simon; Moss, Jon

    2009-09-15

    The objective of this study was to audit current practice in iliac artery intervention in the United Kingdom. In 2001 the British Society of Interventional Radiology Iliac Artery Angioplasty-Stent (BIAS) III registry provided the first national database for iliac intervention. It recommended that data collection needed to continue in order to facilitate the dissemination of comparative data to individual units. BIAS III was designed to continue this work and has a simplified data set with an online submission form. Interventionalists were invited to complete a 3-page tick sheet for all iliac angioplasties and stents. Questions covered risk factors, procedural data, and outcome. Data for 2233 patients were submitted from 37 institutions over a 43-month period. Consultants performed 80% of the procedures, 62% of which were for claudication. Fifty-four percent of lesions were treated with stents and 25% of patients underwent bilateral intervention, resulting in a residual stenosis of <50% in 98%. Ninety-seven percent of procedures had no limb complication and there was a 98% inpatient survival rate. In conclusion, these figures provide an essential benchmark for both audit and patient information. National databases need to be expanded across the range of interventional procedures, and their collection made simple and, preferably, online.

  2. British Society of Interventional Radiology Iliac Artery Angioplasty-Stent Registry III.

    PubMed

    Uberoi, Raman; Milburn, Simon; Moss, Jon; Gaines, Peter

    2009-09-01

    The objective of this study was to audit current practice in iliac artery intervention in the United Kingdom. In 2001 the British Society of Interventional Radiology Iliac Artery Angioplasty-Stent (BIAS) III registry provided the first national database for iliac intervention. It recommended that data collection needed to continue in order to facilitate the dissemination of comparative data to individual units. BIAS III was designed to continue this work and has a simplified data set with an online submission form. Interventionalists were invited to complete a 3-page tick sheet for all iliac angioplasties and stents. Questions covered risk factors, procedural data, and outcome. Data for 2233 patients were submitted from 37 institutions over a 43-month period. Consultants performed 80% of the procedures, 62% of which were for claudication. Fifty-four percent of lesions were treated with stents and 25% of patients underwent bilateral intervention, resulting in a residual stenosis of <50% in 98%. Ninety-seven percent of procedures had no limb complication and there was a 98% inpatient survival rate. In conclusion, these figures provide an essential benchmark for both audit and patient information. National databases need to be expanded across the range of interventional procedures, and their collection made simple and, preferably, online. PMID:19644643

  3. Primary success and one-year followup of percutaneous peripheral excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Visona, Adriana; Liessi, Guido; Miserocchi, Luigi; Bonanome, Andrea; Lusiani, Luigi; Breggion, Giovanni; Pagnan, Antonio

    1992-08-01

    Excimer laser angioplasty was performed in 59 patients (44 males and 17 females, mean age 63 +/- 9 years, range 39 - 77) affected by peripheral vascular disease. Fifty patients had a total occlusion of the superficial femoral artery, three of the iliac artery, and one of the popliteal artery; seven patients showed a subocclusive stenosis of the superficial femoral artery. A commercial excimer laser (Technolas Max-10) was used at the Xenon-Chloride wavelength of 308 nm. The laser operated at 120 ns pulse length and at 20 Hz repetition rate. Applied energy fluence was 20 mJ/pulse. The energy was delivered through a multifiber catheter, which combines 12 (7F) or 18 (9F) fibers (260 micron diameter each), concentrically arranged. Balloon dilatation was associated in 51 patients. Successful recanalization was obtained in 59 out of 61 patients (97%). Failure to recanalize the occluded arteries occurred in two cases, and was due to dissection. Early thrombosis and reocclusion (within 48 hours) was observed in five patients. The cumulative patency rate was 56% at one year. On the basis of these results, excimer laser assisted angioplasty seems a feasible and safe procedure. However, this technique did not solve the restenosis problem. A wide application of excimer laser as a stand alone approach can be foreseen for treatment of peripheral vascular disease.

  4. Use of mechanical devices for distal hemoperfusion during balloon catheter coronary angioplasty.

    PubMed

    Heibig, J; Angelini, P; Leachman, D R; Beall, M M; Beall, A C

    1988-01-01

    Previous attempts to protect the dependent myocardium during balloon catheter coronary angioplasty in animals and humans have had generally unsatisfactory results. This paper summarizes the authors' experience in investigating commercially available mechanical pumps for distal coronary hemoperfusion during balloon angioplasty. Both roller and piston pumps can attain adequate distal perfusion without significant side effects in the majority of patients. Our goal was to suppress angina for at least 5 min to prolong balloon inflation in awake patients. Minor T-wave changes without concomitant angina pectoris can be expected when the distal coronary bed is perfused with hypothermic blood. Side branch occlusion by the inflated balloon prevents effective protection of the corresponding part of the dependent myocardium during distal hemoperfusion, which may result in persistent angina and ST-T changes uncorrected by increasing the hemoperfusion rate. Distal coronary diffuse spasm, rare and transient, was the only immediate complication of this procedure. It is suggested that intense local wall stimulation could occur with a higher flow rate (jet effect). Improved balloon catheter pressure/flow characteristics and on-line continuous mechanical pumps should soon make distal coronary hemoperfusion through balloon catheters an accepted clinical technique. PMID:2973837

  5. Platelet deposition at angioplasty sites and its relation to restenosis in human iliac and femoropopliteal arteries

    SciTech Connect

    Minar, E.; Ehringer, H.; Ahmadi, R.; Dudczak, R.; Leitha, T.; Koppensteiner, R.; Jung, M.; Stuempflen, A.

    1989-03-01

    The amount and time course of platelet accumulation at angioplasty sites and influence of these platelets on restenosis after percutaneous transluminal angioplasty (PTA) in peripheral arteries were determined in 92 patients, who received either a high or low dose of aspirin. Platelet deposition was quantitated by means of dual-radiotracer scintigraphy and calculation of a platelet accumulation index (PAI). The PAI was higher (P less than .05) 4-6 hours after PTA compared with that on subsequent days. There was a trend toward greater platelet accumulation in vessels with extensive dissection. Platelet accumulation at the PTA site occurred with both doses of aspirin, with no differences between the two dosage groups. Twenty-one of 67 patients who underwent PTA in the femoropopliteal segment developed restenosis during a median follow-up of 14 months. The median PAI at 4-6 and 22-24 hours after PTA was significantly less in these 21 patients than in the 46 without restenosis. The data suggest that use of antiplatelet agents to prevent platelet deposition after PTA may not be useful for prevention of restenosis.

  6. Interleukin-6 and Asymmetric Dimethylarginine Are Associated with Platelet Activation after Percutaneous Angioplasty with Stent Implantation

    PubMed Central

    Gremmel, Thomas; Perkmann, Thomas; Kopp, Christoph W.; Seidinger, Daniela; Eichelberger, Beate; Koppensteiner, Renate; Steiner, Sabine; Panzer, Simon

    2015-01-01

    Data linking in vivo platelet activation with inflammation and cardiovascular risk factors are scarce. Moreover, the interrelation between endothelial dysfunction as early marker of atherosclerosis and platelet activation has not been studied, so far. We therefore sought to investigate the associations of inflammation, endothelial dysfunction and cardiovascular risk factors with platelet activation and monocyte-platelet aggregate (MPA) formation in 330 patients undergoing angioplasty with stent implantation for atherosclerotic cardiovascular disease. P-selectin expression, activation of glycoprotein IIb/IIIa and MPA formation were determined by flow cytometry. Interleukin (IL)-6, high sensitivity C-reactive protein and asymmetric dimethylarginine (ADMA) were measured by commercially available assays. IL-6 was the only parameter which was independently associated with platelet P-selectin expression and activated GPIIb/IIIa as well as with leukocyte-platelet interaction in multivariate regression analysis (all p<0.05). ADMA was independently associated with GPIIb/IIIa activation (p<0.05). Patients with high IL-6 exhibited a significantly higher expression of P-selectin than patients with low IL-6 (p=0.001), whereas patients with high ADMA levels showed a more pronounced activation of GPIIb/IIIa than patients with low ADMA (p=0.003). In conclusion, IL-6 and ADMA are associated with platelet activation after percutaneous angioplasty with stent implantation. It remains to be established whether they act prothrombotic and atherogenic themselves or are just surrogate markers for atherosclerosis with concomitant platelet activation. PMID:25807315

  7. Ressourceneinsatzplanung In der Energie- und Verfahrenstechnik

    NASA Astrophysics Data System (ADS)

    Engell, Sebastian; Handschin, Edmund; Rehtanz, Christian; Schultz, Rüdiger

    Der ökologisch nachhaltige, wirtschaftlich effiziente und politisch faire Umgang mit den Ressourcen der Erde ist eine der größten Herausforderungen an die Menschheit im 21. Jahrhundert und impliziert Paradigmenwechsel in allen Bereichen des gesellschaftlichen Lebens. Energie- und Verfahrenstechnik sind traditionell Bereiche, in denen der optimale Umgang mit kostbaren und beschränkt verfügbaren Ressourcen von erstrangiger Bedeutung ist. Zur Lösung der damit verbundenen komplexen Entscheidungsprobleme sind mathematische Methoden schon seit längerem im Einsatz. Hierbei können aber noch längst nicht alle bislang aufgetretenen Probleme fundiert angegangen werden. Der wachsende wirtschaftliche und ökologische Druck auf die Effizienz der Produktions-und Versorgungssysteme sowie stärkere Schwankungen von Angebot und Nachfrage führen zu neuen Herausforderungen, für die neue mathematische Methoden und Algorithmen entwickelt werden müssen.

  8. Welt und Wirkungsprinzip (2nd Aufl.)

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    2010-03-01

    Modell einer kausalen Bewirkung der Welt, und logische, geometrische, physikalische Interprätation dieser Kausalmenge und Fortwirkung der frühsten ihrer sukzessiv als echt Neues bewirkten und durch Vorhandenes oder Späteres nicht darstellbaren oder widerrufbaren Ereignisse als Dimensionen und sie verkörpernde primäre Naturkräfte, mit Korrespondenz zur beobachteten Welt und ihrer grundlegendsten Eigenschaften. Wirklich ist nur was wirkt, wo und wie. Entsprechend ist im Bogenelement statt der Eigenzeit die variante Anzahl Wirkungen relevant, 0 ≈ 1/h2 dS2 - 1/tpl2 (dt2 - 1/c2 {dq12 + G02/G2 [dq2,32 - ...]}) mit G0 = c4lpl/Epl ≈ G. Die heutigen Dimensionen und Naturkräfte entstanden in dieser Reihenfolge, haben 'komplementäre' aber gleichwertige statische und dynamische Aspekte, entsprechend ihren Termen in Bogenelement bzw. Vierervektor, aus derem Vergleich sowie mit denen ihrer Nachbarn folgen Grundgleichungen bzw. Erhaltungssätze. Jeweils individuelle Eigenschaften wie ihre Naturkonstante konkretisieren sie und tragen zu gattungsmäßigen wie globale Affinität und Äquivalenzen bei. Ältestes Gebiet oder räumlicher Rand jeder Dimension sind die ersten vom Vorgänger bewirkten Ereignisse, selbst raumzeitlicher Ursprung des Nachfolgers, dort einmalig und ewig maximal rotverschoben fortwirkend und nicht lokalisierbar, um neue Elementareinheiten verschieden und lichtartig mit deren Verhältnis oder dem ihrer globalen Zustandsgrößen als konstanten Anfangsimpuls, Expansion, Längen- oder Ereignisdichte zueinander. Der Übergang vom diskreten Modell weniger Informationen zum Kontinuum und die Korrespondenz zur Physik ist problemlos, Details wie ein kontinuierlicher, abrupter oder ganz fehlender Abfall der Metrik beim ältesten Gebiet sind aber nur durch Beobachtungen entscheidbar. Erörtert werden allgemeine und individuelle Eigenschaften und ihre Konsequenzen der Dimensionen mit ihren Kräften, selbst und im Verhältnis zueinander, etwa ihrer begrenzten

  9. Efficacy of Local Molsidomine Delivery from a Hydrogel-Coated Angioplasty Balloon Catheter in the Atherosclerotic Porcine Model

    SciTech Connect

    Rolland, Pierre H.; Mekkaoui, Choukri; Palassi, Maria; Friggi, Alain; Moulin, Guy; Piquet, Philippe; Bartoli, Jean-Michel

    2003-02-15

    Purpose: To evaluate the therapeutic effects of local molsidomine delivery via a hydrogel-coated angioplasty balloon catheter during overstretch angioplasty in atheroscleroticswine iliac vessels. Molsidomine is retained in the arterial wall after local delivery for more than 72 hr and is slowly metabolized intolinsidomine, releasing nitric oxide (NO). Methods: A hydrogel-coated angioplasty balloon catheter was used to both deliver drug locally (150 mg molsidomine or placebo in the contralateral vessel) and dilate iliac vessels in nine Pietrin pigs that had been on an atherogenic diet for 5 months. Animals were killed at 3 hr(n = 2), 24 hr (n = 3) and 3 months(n = 3) after treatment. Iliac arteries were examined for wall pulsatility, histomorphometry, cell proliferation and platelet aggregation. Results: No significant therapeutic effects were detected 3 hr after treatment. At 24 hr, wall pulsatility,thrombo resistance and vascular cell homeostasis were significantly restored in the molsidomine-treated versus placebo group. At 3 months,molsidomine inhibited restenotic lesion development, except in scarred areas of histologically detectable adventitial/medial dissection. Conclusion: Local delivery of concentrated molsidomine from a hydrogel-coated angioplasty balloon catheter resulted in early NO-dependent vasodilation/stress normalization and antithrombotic and antiproliferative effects. In the medium term, molsidomine inhibited restenosis in the absence of vessel dissection.

  10. Systemic Hypertension and Transient Ischemic Attack in a 6-Year-Old Girl with Fibromuscular Dysplasia Treated with Percutaneous Angioplasty

    SciTech Connect

    Foa-Torres, Gustavo; Ganame, Javier; Juaneda, Ernesto; Peirone, Alejandro; Barcudi, Maria Silvina; Achaval, Alberto

    2010-02-15

    We describe a 6-year-old girl with arterial hypertension secondary to fibromuscular dysplasia with stenoses of both renal arteries and transient ischemic attack due to extracranial right internal carotid artery subtotal occlusion as well as left internal carotid artery stenosis. She was treated with percutaneous angioplasty of both renal and both carotid arteries.

  11. Cryoplasty Versus Conventional Angioplasty in Femoropopliteal Arterial Recanalization: 3-Year Analysis of Reintervention-Free Survival by Treatment Received

    SciTech Connect

    Diaz, Maria Lourdes; Urtasun, Fermin Barberena, Javier; Aranzadi, Carlos; Guillen-Grima, Francisco; Bilbao, Jose Ignacio

    2011-10-15

    Purpose: To compare long-term efficacy of cryoplasty therapy versus conventional angioplasty in the treatment of peripheral arterial atherosclerotic stenosis on the basis of our 3-year clinical experience. Materials and Methods: From January 2006 to December 2008, a total of 155 patients with 192 lesions of the femoropopliteal sector were randomized to receive either cryoplasty or conventional balloon angioplasty. The primary study end point was lesion target patency. Follow-up with clinical evaluation of patient's symptoms, ankle-brachial index, and Doppler ultrasound was scheduled at 1, 6, 9, 12, 24, and 36 months. Results: For the cryoplasty group (n = 86), technical immediate success was achieved in 74.4% of lesions. Rate of significant dissection was 13.5% and rate of stent placement of 22%. In the long term, target lesion patency rate at 6 months was 59.4%, with rates of 55.9, 52.6, and 49.1% at 1, 2, and 3 years, respectively. For the conventional angioplasty group (n = 69), the immediate technical success rate was 83.7%. Rate of significant dissection was 19%, and rate of stent placement was 72.9%. Patency rates at 6 months and at 1, 2, and 3 years were 71.5, 61.2, 60, and 56%, respectively. Conclusion: Compared with conventional angioplasty, cryoplasty showed good immediate success rates with lower stent placement rates. During the 3-year follow-up, patency rates tended to equalize between the two modalities.

  12. THE CORONARY ARTERY HISTOPATHOLOGIC RESPONSE TO ANGIOPLASTY BALLOON INJURY IN A SWINE MODEL IS GENDER- AND HORMONAL-DEPENDENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of gender and exogenous estrogen on the histopathologic response of the left anterior descending coronary artery (LAD) to angioplasty balloon over-inflation were examined in this study. In addition, we sought to develop an animal model to predict adequately the effects of cardiovascular ...

  13. Primary Cutting Balloon Angioplasty for Treatment of Venous Stenoses in Native Hemodialysis Fistulas: Long-Term Results from Three Centers

    SciTech Connect

    Bhat, Rajesh McBride, Kieran; Chakraverty, Sam; Vikram, Raghunandan; Severn, Alison

    2007-11-15

    Aim. To evaluate the technical success and patency rates following primary cutting balloon angioplasty for venous stenoses in native dialysis fistulas. Methods. Forty-one patients (26 men, 15 women; age range 26-82 years, average age 59 years) underwent 50 (repeat procedures in 9 patients) primary cutting balloon (PCB) angioplasty procedures in three institutions by three primary operators. The indication was primary stenosis in 21 patients, recurrent lesions in 15, and immature fistulas in 5. A PCB was used alone in 17 cases, but was followed by a larger standard balloon in 33 cases. Follow-up included ultrasound, flow analysis and urea reduction ratio, and ranged from 2 to 30 months (mean 14 months). Results. The technical success rate was 98%. All procedures were relatively painless. Two PCBs burst and 4 leaked, but without causing any morbidity. Nineteen fistulas were still working at last follow-up. Primary patency rates at 6, 12, and 24 months using Kaplan-Meier analysis were 88%, 73%, and 34%, respectively, and the primary assisted patencies were 90%, 75%, and 50%, respectively. Conclusion. PCB angioplasty has high technical success and low complication rates. The long-term patency rates are favorable for PCB angioplasty and compare favorably with other series.

  14. [Evidenzbasierte Leitlinien, Anspruch und Wirklichkeit].

    PubMed

    Gutsch, Johannes; Reif, Marcus; Müller-Hübenthal, Boris; Matthiessen, Peter F

    2016-01-01

    Mit der Konzeption der «Evidenzbasierten Medizin» und den «Evidenzbasierten Leitlinien» soll mithilfe von Formalisierungsprozeduren die ärztliche Irrtumsanfälligkeit kalkulierbar gemacht werden. Quantifizierte objektive Aussagen über die therapeutische Wirksamkeit einer Behandlung sollen die individuelle ärztliche Beurteilung der therapeutischen Wirksamkeit überflüssig machen. Damit kommt der Befolgung von formalen Regeln die entscheidende Rolle bei der Beantwortung der Frage nach dem Wahrheitsgehalt und dem Wirklichkeitsbezug zu. Im Rahmen evidenzbasierter Leitlinien werden vorrangig die Ergebnisse randomisierter kontrollierter Studien (RCT) oder Meta-Analysen solcher Studien herangezogen. Am Beispiel der S3-Leitlinie «Malignes Melanom» wird hier eine evidenzbasierte Urteilsbildung zur Wirksamkeit einer unkonventionellen Therapie - hier mit einem Mistelpräparat - analytisch nachvollzogen. Die für die Beurteilung dieser unkonventionellen Therapie herangezogene randomisierte Studie wird genauer methodisch analysiert. Obwohl sie keine statistisch basierte Aussage zulässt, wurde eine Leitlinienempfehlung auf Basis dieser Studie abgeleitet. Es wird gezeigt, dass 1) allein die Existenz einer einzigen RCT mit hoher Evidenz gleichgesetzt wird, 2) die Ergebnisse trotz beträchtlicher Fehlinterpretationen in eine S3-Leitlinie einfließen und 3) Meinungen anstelle kritischer wissenschaftlicher Analysen verarbeitet werden. Unsere Untersuchung zeigt, dass noch so ausgefeilte epistemologische und methodologische Formalien den Arzt nicht von der Pflicht entbinden, auf Basis seiner ärztlichen Erfahrung und professionellen Kompetenz den Realitätswert der ihm zur Verfügung stehenden Information zu beurteilen. PMID:27161555

  15. [Vegetarische und vegane Ernährung bei Kindern - Stand der Forschung und Forschungsbedarf].

    PubMed

    Keller, Markus; Müller, Stine

    2016-01-01

    Die Praxis vegetarischer Ernährungsformen ist in Deutschland im letzten Jahrzehnt deutlich angestiegen. Allerdings ist der Anteil vegetarischer und veganer Kinder dabei unbekannt. Studien mit Erwachsenen zeigen das präventive Potenzial, aber auch potenzielle Schwachstellen pflanzenbasierter Kostformen. Die Vorteile und Risiken einer vegetarischen bzw. veganen Ernährung im Kindesalter wurden bisher jedoch relativ selten untersucht. Außerdem lassen das unterschiedliche Alter der Kinder, das heterogene Studiendesign sowie die teilweise geringe Probandenzahl der Studien keine verbindlichen Aussagen zu. In dieser Übersichtsarbeit werden die Ergebnisse der wenigen Studien zu vegetarisch und vegan ernährten Kindern (< 12 Jahren) in Nordamerika und Europa zusammengefasst. Demnach lag die Zufuhr von Nahrungsenergie und Makronährstoffen vegetarischer und veganer Kinder meist näher an den Empfehlungen der Fachgesellschaften als die Ernährung gleichaltriger Mischkostkinder. Ebenso wiesen vegetarisch und vegan ernährte Kinder eine höhere Zufuhr von und bessere Versorgung mit verschiedenen Vitaminen und Mineralstoffen auf. Häufiger zeigten sich jedoch Defizite bei Vitamin B12, Zink, Kalzium, Eisen und Vitamin D. Das Wachstum und die Entwicklung vegetarisch und vegan ernährter Kinder entsprachen weitgehend den Referenzstandards, wobei sie dazu tendierten, leichter, schlanker und (< 5 Jahren) auch kleiner zu sein. Aufgrund der unzureichenden Studienlage besteht erheblicher Forschungsbedarf zu den Auswirkungen einer vegetarischen und veganen Ernährung im Kindesalter. PMID:27160086

  16. Percutaneous Transluminal Angioplasty and Enclosed Thrombolysis Versus Percutaneous Transluminal Angioplasty in the Treatment of Femoropopliteal Occlusions: Results of a Prospective Randomized Trial

    SciTech Connect

    Nicholson, Tony

    1998-11-15

    Purpose: To determine whether percutaneous transluminal angioplasty (PTA) and enclosed thrombolysis (ET) is superior to PTA alone in the treatment of femoropopliteal occlusions. Methods: Twenty-five patients with 5-15-cm-long occlusions in the femoropopliteal segments, with otherwise normal run-in arteries and at least one normal tibioperoneal artery to the foot, were randomized to ET/PTA or PTA alone. Ankle brachial systolic index (ABI) was measured before the procedure and at 24 hr and 12 months after the procedure, when a duplex scan was also carried out. End points in the study were patency at, or repeat intervention before, 12 months. Results: Procedures were successful in 23 of 25 patients. There was one immediate occlusion of tibioperoneal arteries, and one early reocclusion of a reopened segment in the ET/PTA group. There was one early reocclusion in the PTA group. At 12 months patency was 70% and 69.2% in the ET/PTA and PTA groups respectively. Covariant analysis showed no significant difference in ABI between the two groups at any of the three measurement times. Conclusion: This trial demonstrated no difference between ET/PTA and PTA alone in femoropopliteal occlusions associated with normal proximal arteries and at least one normal tibioperoneal artery.

  17. Restaurierung von Seen und Renaturierung von Seeufern

    NASA Astrophysics Data System (ADS)

    Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte

    Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.

  18. Bewegungsapparat: Postcraniales Skelett und Muskulatur

    NASA Astrophysics Data System (ADS)

    Fischer, Martin S.

    Der Bewegungsapparat bestimmt die Form des Wirbeltierkörpers. So lässt sich z. B. aus der Gestalt eines Fisches auf seine bevorzugt e Schwimmweise schließen (S. 61). Bei den aquatisch en Schädeltieren dominiert die Fortbewegung mit axialem Antrieb; bei den meisten Tetrapoda findet sich eine Kombination aus axialem Antrieb und Bewegung durch Gliedmaßen. Selbst beim höchst spezialisierten Gang, der bipeden Bewegung des Menschen, sind Torsionsbewegungen des Rumpfes noch maßgeblich und bestimmen auch die Grundform des menschlichen Körpers (z. B. die Taille). Obwohl die verschiedenen Antriebsmechanismen eine funktionelle Einheit bilden, werden im Folgenden das Axialskelett sowie der Schulter- und Beckengürtel mit den zugehörigen Extremitäten getrennt besprochen.

  19. Cutting Balloon Angioplasty of Bilateral Renal Artery Stenosis Due to Takayasu Arteritis in a 5-Year-Old Child with Midterm Follow-Up

    SciTech Connect

    Gumus, Burcak Cevik, Halime; Vuran, Can; Omay, Oguz; Kocyigit, Ozgen Ilgaz; Turkoz, Riza

    2010-04-15

    The aim of this report is to demonstrate the successful endovascular treatment of bilateral renal artery stenosis due to Takayasu arteritis by cutting balloon angioplasty in a 5-year-old child with mid-term follow-up.

  20. Percutaneous pulmonary vein stenosis angioplasty complicated by rupture: successful stenting with a polytetrafluoroethylene-covered stent.

    PubMed

    Matsumoto, Takashi; Zahn, Evan M; Kar, Saibal

    2014-06-01

    A 47-year-old-man with prior pulmonary vein (PV) isolation for atrial fibrillation developed progressive shortness of breath and was found to have total occlusion of the left lower and significant stenosis in left upper PV. A ventilation/perfusion scan showed decreased left lung perfusion. Percutaneous PV stenosis angioplasty was complicated by the rupture of left lower PV with pericardial tamponade; successful stenting with a polytetrafluoroethylene-covered stent was performed. Follow-up studies at nine months showed patency of both veins with a normal ventilation perfusion scan. In this article, we will discuss acquired PV stenosis following PV isolation, percutaneous PV intervention, and the literature supporting the procedure. PMID:24590687

  1. Clinical results and quality of life after percutaneous transluminal coronary angioplasty: a preliminary report.

    PubMed

    McKenna, K T; McEniery, P T; Maas, F; Aroney, C N; Bett, J H; Cameron, J; Garrahy, P; Holt, G; Hossack, K F; Murphy, A L

    1992-10-01

    To evaluate the effect of percutaneous transluminal coronary angioplasty (PTCA) on quality of life, data on symptomatic status, functional capacity, life satisfaction, and psychological wellness were collected on 102 patients at 1 day pre-PTCA and 2 months post-PTCA, and on the first 50 of these patients at 10 months post-PTCA. There were highly significant changes (p < 0.001) in all quality of life measures between pre-PTCA and the 1st follow-up measurements. No further significant changes occurred in these measures between the 1st and 2nd follow-up measurements, indicating that the initial improvement in quality of life was sustained over this period. Data on primary success rate, complications, and pre- and post-PTCA risk factor scores are also reported. PMID:1446341

  2. Usefulness of intraoperative coronary angioplasty in aorto-coronary bypass surgery.

    PubMed

    Ban, T; Sakata, R; Soneda, J; Matsuda, M; Nishimura, K; Hirata, K; Mochizuki, T

    1985-10-01

    Seven patients underwent aorto-coronary bypass grafting combined with intraoperative transluminal coronary angioplasty (OTCA), because of multiple obliteration of the coronary arteries with poor distal run-off. The patients were all males with a mean age of 52.6 years. For OTCA, a SIMPSON-ROBERT vascular dilator system was used. Eight stenoses in seven patients, four in the left anterior descending artery (LAD) and three in the right coronary artery (RCA) were dilated by means of OTCA. In five patients the results were satisfactory but in two patients the procedures resulted in failure. Dilatation failed because of severe calcification of LAD in one case and, in the other, distal RCA was completely obstructed by a compressed atherosclerotic plaque at the bifurcation after the procedure. From these limited experiences we believe that OTCA might be a method of selection to treat the patients with coronary sclerosis with poor distal run-off. PMID:2935652

  3. Transauricular balloon angioplasty in rabbit thoracic aorta: a novel model of experimental restenosis

    PubMed Central

    2014-01-01

    Background The aim of this study was to demonstrate a percutaneous transauricular method of balloon angioplasty in high-cholesterol fed rabbits, as an innovative atherosclerosis model. Methods Twenty male New Zealand rabbits were randomly divided into two groups of ten animals, as follows: atherogenic diet plus balloon angioplasty (group A) and atherogenic diet alone (group B). Balloon angioplasty was performed in the descending thoracic aorta through percutaneous catheterization of the auricular artery. Eight additional animals fed regular diet were served as long term control. At the end of 9 week period, rabbits were euthanized and thoracic aortas were isolated for histological, immunohistochemical and biochemical analysis. Results Atherogenic diet induced severe hypercholesterolemia in both group A and B (2802 ± 188.59 and 4423 ± 493.39 mg/dl respectively) compared to the control animals (55.5 ± 11.82 mg/dl; P < 0.001). Group A atherosclerotic lesions appeared to be more advanced histologically (20% type IV and 80% type V) compared to group B lesions (50% type III and 50% type IV). Group A compared to group B atherosclerotic lesions demonstrated similar percentage of macrophages (79.5 ± 9.56% versus 84 ± 12.2%; P = 0.869), more smooth muscle cells (61 ± 14.10% versus 40.5 ± 17.07; P = 0.027), increased intima/media ratio (1.20 ± 0.50 versus 0.62 ± 0.13; P = 0.015) despite the similar degree of intimal hyperplasia (9768 ± 1826.79 μm2 versus 12205 ± 8789.23 μm2; P = 0.796), and further significant lumen deterioration (23722 ± 4508.11 versus 41967 ± 20344.61 μm2; P = 0.05) and total vessel area reduction (42350 ± 5819.70 versus 73190 ± 38902.79 μm2; P = 0.022). Group A and B animals revealed similar nitrated protein percentage (P = NS), but significantly higher protein nitration compared to control group (P < 0.01; P < 0.01, respectively

  4. What practical factors guide the choice of stent and protection device during carotid angioplasty?

    PubMed

    Bosiers, M; Deloose, K; Verbist, J; Peeters, P

    2008-06-01

    The importance of angioplasty and stenting in the treatment of carotid artery disease cannot be underestimated. Successful carotid stenting does not only depend of the operator's skills and experience, but also an adequate selection of cerebral protection devices and carotid stents can help avoiding neurological complications. A broad spectrum of carotid devices is currently on the market and since all have their assets and downsides, it is virtually impossible to acclaim one specific device as being the best. The individual characteristics of each specific protection system or stent may make it an attractive choice in one circumstance, but render it a less desirable option in others situations. The applicability depends primarily on the arterial anatomy and the specific details of the lesion being treated. But certainly, personal preferences and familiarity with a specific device may legitimately influence the decision to choose one over another. PMID:18375153

  5. Iatrogenic Subtotal Stenosis of the Right Subclavian Artery Treated With Percutaneous Transluminal Angioplasty

    SciTech Connect

    Smeenk, Robert M.; Kock, Mark C. J. M.; Elgersma, Otto E. H.; Schnater, Marco J.

    2011-02-15

    This report describes a rare vascular complication of surgical placement of a marking clip and a possible approach to problem solving. A 55-year-old patient presented with loss of sensation in the fingers and loss of peripheral pulsations in the right arm 4 days after right upper lobectomy for a pT2N1 moderately differentiated adenocarcinoma of the lung. Duplex examination and computed tomography were performed the same day and showed a subtotal stenosis of the right subclavian artery, which was caused by the surgical placement of a metal clip to mark the surgical boundary. Selective angiography was subsequently performed. Percutaneous transluminal angioplasty (PTA) successfully dilated the stenosis and pushed the clip off. Flow in the right subclavian artery (RSA) was completely restored as were neurology and peripheral pulses. In conclusion, arterial stenosis by a surgical (marking) clip may be feasibly treated with PTA.

  6. Preliminary results utilizing a new percutaneous transluminal coronary angioplasty balloon catheter.

    PubMed

    Talley, J D; Joseph, A; Kupersmith, J

    1990-06-01

    We report our initial experience with a new percutaneous transluminal coronary angioplasty (PTCA) balloon catheter and compare it to a similar over-the-wire system in a retrospective, nonrandomized fashion. There was no statistical difference in pre-PTCA angiographic indices and post-PTCA angiographic and clinical success rates between the two groups. There was a trend toward a decrease in length of fluoroscopy (P = .08) and a significant decrease in the amount of contrast utilized (P = .007) with the new balloon catheter. Several new construction features of the new catheter account for this improvement and are discussed. The long-term success of this balloon catheter remains to be investigated. PMID:2354509

  7. [A Case of Vertebral Artery Stenosis Presenting with Progressing Stroke and Treated by Percutaneous Transluminal Angioplasty].

    PubMed

    Hayashi, Kentaro; Matsuo, Yoshitaka; Toyoda, Keisuke; Hayashi, Yukishige; Shirakawa, Kiyoshi; Kaminogo, Makio

    2016-05-01

    A 75-year-old man with a history of diabetes mellitus and hypertension was suffered from dizziness and vomiting and brought to the near-by hospital. MRI showed cerebellar infarction due to right vertebral artery stenosis. Despite best medical treatment, the infarction progressed day by day and he was transferred to our hospital five days later. Neurological examination showed mild disturbance of consciousness and right hemiparesis. Right vertebral angiography revealed high-grade stenosis accompanied with atherosclerosis at the V3-V4 portion. Percutaneous transluminal angioplasty(PTA)was performed with 2.5mm×14mm balloon with 6 atm dilation. Postoperative course was uneventful and no further stroke occurred after the treatment. PTA was effective for vertebral artery stenosis manifested with progressing stroke. The indication of stent placement for the cerebral artery should be prudent. PMID:27166843

  8. Intravascular Ultrasound and Histology in In Vitro Assessment of Iliac Artery Angioplasty

    SciTech Connect

    Lankeren, Winnifred van; Gussenhoven, Elma J.; Qureshi, Akeel; Lugt, Aad van der

    1999-01-15

    Purpose: Intravascular ultrasound (IVUS) was used to assess in vitro the morphologic and quantitative effects of balloon angioplasty (PTA) of the iliac artery. Methods: Forty human iliac arteries ({>=} 30% area stenosis) were studied with IVUS in vitro before and after PTA and the findings were validated with histology. Results: The sensitivity of IVUS for dissection was 74% and for media rupture 59%. The incidence of vascular damage was higher when the whole segment was analyzed rather than the target site alone. Dissections occurred at the thinnest region of the plaque, unrelated to plaque calcification. Following PTA, quantitative changes at the target site were greater compared with the overall data derived from all cross-sections. The increase in lumen area was caused solely by an increase in vessel area. Conclusions: IVUS is sensitive in detecting dissections, which occurred irrespective of calcification at the thinnest region of the plaque. The increase in lumen area after PTA was caused by stretching of the vessel.

  9. Stent-Graft for the Management of Hepatic Artery Rupture Subsequent to Transcatheter Thrombolysis and Angioplasty in a Liver Transplant Recipient

    SciTech Connect

    Yamakado, Koichiro Nakatsuka, Atsuhiro; Takaki, Haruyuki; Usui, Masanobu; Sakurai, Hiroyuki; Isaji, Shuji; Uemoto, Shinji; Takeda, Kan

    2008-07-15

    Arterial rupture subsequent to angioplasty occurs in about 5% of cases. Thrombolysis with re-establishment of flow without resolving underlying anatomic defects such as hepatic arterial stenosis leads to re-thrombosis. We present a case of arterial anastomotic rupture after thrombolysis and angioplasty of an underlying anastomotic hepatic arterial stenosis. Both the underlying anatomic defect and the rupture were resolved successfully with placement of a stent-graft, with a resultant patent artery for 1 year after the procedure.

  10. Characterization of Pebax angioplasty balloon surfaces with AFM, SEM, TEM, and SAXS.

    PubMed

    Warner, Jacob A; Forsyth, Bruce; Zhou, Fang; Myers, Jason; Frethem, Chris; Haugstad, Greg

    2016-04-01

    In the medical device industry, angioplasty balloons have been widely used in the less invasive treatment of heart disease by expanding and relieving clogged structures in various arterial segments. However, new applications using thin coatings on the balloon surface have been explored to enhance therapeutic value in the delivery of pharmaceuticals (drug-elution) or control thermal energy output (RF ablation). In this study, angioplasty balloon materials comprised of poly(ether-block-amide) (Pebax) were investigated via atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering (SAXS) to characterize physical properties at the balloon surface that may affect coating adhesion. The soft segment of this Pebax 1074 material is polyethylene oxide (PEO) and the hard segment is nylon-12. The morphology of the hard segments of this block co-polymer are found via AFM stiffness measurements to be (40 ± 20) nm by (300 ± 150) nm and are oriented parallel to the surface of the balloon. SAXS measurements found the lamellar spacing to be (18.5 ± 0.5) nm, and demonstrate a preferential orientation in agreement with TEM and AFM measurements. Fixation of this balloon in resin, followed by cryo-sectioning is shown to provide a novel manner in which to investigate surface characteristics on the balloon such as material or coating thickness as well as uniformity in comparison to the bulk structure. These outputs were deemed critical to improve overall balloon processing such as molding and surface treatment options for robust designs toward better procedural outcomes targeting new therapeutic areas. PMID:25891789

  11. Critical appraisal of paclitaxel balloon angioplasty for femoral-popliteal arterial disease.

    PubMed

    Herten, Monika; Torsello, Giovanni B; Schönefeld, Eva; Stahlhoff, Stefan

    2016-01-01

    Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB) concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1) medical journals (ie, MEDLINE), 2) international registers for clinical studies (ie, www.clinicaltrials.gov), and 3) abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel -DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been contraindicated until now (ie, bifurcation, ostial lesions), and in leaving no stent scaffold behind. Reinterventions are easier to perform because DCBs leave no metal behind. Various combinations of DCBs with other treatment modalities may prove to be viable options in future. The follow-up results of clinical studies will evaluate the long-term impact

  12. Patient Experience, Pain, and Quality of Life after Lower Limb Angioplasty: A Multisite Prospective Cohort Study

    SciTech Connect

    Culverwell, A. D.; Tapping, C. R.; Ettles, D. F.; Kessel, D.

    2012-08-15

    Purpose: To explore the experience of patients undergoing endovascular lower limb angioplasty and evaluate the improvements in quality of life and disease-related symptoms after the procedure. Methods: Patients completed a questionnaire before treatment and three questionnaires after the procedure (immediately after the procedure, and again 4 weeks and 3 months later). Anxiety, patient understanding, procedure-related pain, and disease-related pain were assessed by a visual analog score (VAS). Complications, analgesic requirements, and satisfaction were recorded. Changes to quality of life were assessed by the validated SF36 questionnaire. Results: A total of 88 patients (41%) responded. Overall, disease-related pain decreased over 3 months after the procedure. Smokers had more pain both before and after the procedure (P < 0.05). Explanation was considered better if provided by radiologist (P < 0.05). Sixty-nine percent of patients found the procedures less painful (mean VAS 2.5) than they had anticipated (VAS 5.5). Fifty percent of patients experienced adverse effects related to their puncture site, but this was highest among patients who had undergone the procedure before and smokers. The greatest quality-of-life improvements were in emotional and general health. Higher levels of disease-related pain were associated with worse general, emotional, and physical health (P < 0.05). Conclusion: Lower limb angioplasty provides symptomatic and quality-of-life improvements. Implementation of simple measures could improve patient satisfaction-for example, treatment should be explained by the radiologist in advance. Routine prescription of analgesics with particular attention to smokers and those undergoing repeat interventions is suggested.

  13. Effect of gradual computerized angioplasty on outcomes of patients undergoing coronary stenting.

    PubMed

    Leibowitz, David; Lotan, Chaim; Katz, Iony; Nassar, Hisham; Boguslavsky, Larissa; Mosseri, Morris; Jabara, Refat; Varshitzsky, Boris; Danenberg, Haim; Weiss, A Teddy

    2009-07-15

    Mechanical trauma caused by percutaneous coronary intervention is a major factor contributing to subsequent cardiac events, restenosis, and the need for target lesion revascularization (TLR). To minimize this trauma, we developed a Computerized Angioplasty Pressure Sensor and Inflator Device (CAPSID) for gradual inflation. The objective of the present prospective randomized study was to examine whether the use of this novel device reduced TLR, as well as cardiac events, in patients undergoing stenting. Patients undergoing coronary stenting were eligible and randomized to receive CAPSID or standard manual percutaneous coronary intervention. In the CAPSID group, slow, gradual balloon inflation was performed using a personal computer. Patients with acute ST-elevation myocardial infarction or the need for percutaneous coronary intervention for total occlusions, left main disease, and vein grafts were excluded. Clinical follow-up for major adverse cardiac events, including death, acute myocardial infarction, and TLR, was performed at 12 months. A total of 310 patients were enrolled in the study. No significant differences were found in the clinical characteristics between the CAPSID and control groups. At 1 year of follow-up, the CAPSID group had had a significantly lower rate of major adverse cardiac events (8% vs 18%, p <0.01) driven by significantly lower rates of acute myocardial infarction (1% vs 7%, p <0.01) and TLR (5% vs 12%, p <0.05). In conclusion, gradual computerized balloon inflation using CAPSID as a platform for angioplasty and stenting significantly reduced TLR and major adverse cardiac events at 1 year in patients undergoing coronary stenting. The use of this novel device may improve outcomes in patients undergoing coronary stenting. PMID:19576351

  14. Critical appraisal of paclitaxel balloon angioplasty for femoral–popliteal arterial disease

    PubMed Central

    Herten, Monika; Torsello, Giovanni B; Schönefeld, Eva; Stahlhoff, Stefan

    2016-01-01

    Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB) concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1) medical journals (ie, MEDLINE), 2) international registers for clinical studies (ie, www.clinicaltrials.gov), and 3) abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel –DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been contraindicated until now (ie, bifurcation, ostial lesions), and in leaving no stent scaffold behind. Reinterventions are easier to perform because DCBs leave no metal behind. Various combinations of DCBs with other treatment modalities may prove to be viable options in future. The follow-up results of clinical studies will evaluate the long

  15. Excimer laser coronary angioplasty: experience with a prototype multifibre catheter in patients with stable angina pectoris.

    PubMed

    Kochs, M; Haerer, W; Eggeling, T; Hoeher, M; Schmidt, A; Hombach, V

    1992-03-01

    Percutaneous excimer laser coronary angioplasty (ELCA) was performed in a first group of 20 patients with stable angina pectoris caused by significant coronary stenosis, and long-term follow-up was evaluated. Prototype 4 to 5.5 French multifibre catheters with 18-20 quartz fibres of 100 microns diameter, concentrically arranged around a central lumen for taking up a guide wire, were coupled to a commercial XeCl excimer laser. Energy was delivered at a wavelength of 308 nm with a pulse duration of 60 or 120 ns. Operating at a repetition rate of 20 Hz, mean energy transmission was 13.4 +/- 6.8 mJ per pulse. In all but one patient the lesion could be passed by the catheter. Percent diameter stenosis decreased from 77.1 +/- 10.8% to 53.1 +/- 11.8% after ELCA. Complications were frequently observed, intracoronary thrombus formation in eight instances, dissection in six patients and spasm in five cases, causing total vessel occlusion in five procedures. All complications could be managed efficaciously by thrombolytic and vasodilating drugs and/or balloon angioplasty. Subsequent PTCA was performed in case of complication or insufficient stenosis reduction after ELCA in 18 patients with adequate results (residual stenosis, 28.5 +/- 10.2%). Long-term follow-up angiography, which could be performed in 16 of 19 laser treatments, demonstrated significant restenosis in only three patients. Our preliminary results suggest that, using ELCA, ablation of atherosclerotic lesions is feasible in most cases. However, compared with PTCA, stenosis reduction is significantly less, and the acute complication rate is much higher. Thus, further improvements of the catheter system are necessary in order to realize the advantages of excimer laser ablation, which can be demonstrated by experimental studies. PMID:1597220

  16. Potential Utility of the SYNTAX Score 2 in Patients Undergoing Left Main Angioplasty

    PubMed Central

    Madeira, Sérgio; Raposo, Luís; Brito, João; Rodrigues, Ricardo; Gonçalves, Pedro; Teles, Rui; Gabriel, Henrique; Machado, Francisco; Almeida, Manuel; Mendes, Miguel

    2016-01-01

    Background The revascularization strategy of the left main disease is determinant for clinical outcomes. Objective We sought to 1) validate and compare the performance of the SYNTAX Score 1 and 2 for predicting major cardiovascular events at 4 years in patients who underwent unprotected left main angioplasty and 2) evaluate the long-term outcome according to the SYNTAX score 2-recommended revascularization strategy. Methods We retrospectively studied 132 patients from a single-centre registry who underwent unprotected left main angioplasty between March 1999 and December 2010. Discrimination and calibration of both models were assessed by ROC curve analysis, calibration curves and the Hosmer-Lemeshow test. Results Total event rate was 26.5% at 4 years.The AUC for the SYNTAX Score 1 and SYNTAX Score 2 for percutaneous coronary intervention, was 0.61 (95% CI: 0.49-0.73) and 0.67 (95% CI: 0.57-0.78), respectively. Despite a good overall adjustment for both models, the SYNTAX Score 2 tended to underpredict risk. In the 47 patients (36%) who should have undergone surgery according to the SYNTAX Score 2, event rate was numerically higher (30% vs. 25%; p=0.54), and for those with a higher difference between the two SYNTAX Score 2 scores (Percutaneous coronary intervention vs. Coronary artery by-pass graft risk estimation greater than 5.7%), event rate was almost double (40% vs. 22%; p=0.2). Conclusion The SYNTAX Score 2 may allow a better and individualized risk stratification of patients who need revascularization of an unprotected left main coronary artery. Prospective studies are needed for further validation. PMID:27007223

  17. Balloon Angioplasty – The Legacy of Andreas Grüntzig, M.D. (1939–1985)

    PubMed Central

    Barton, Matthias; Grüntzig, Johannes; Husmann, Marc; Rösch, Josef

    2014-01-01

    In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939–1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called “percutaneous transluminal dilatation”. Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920–1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40th anniversary of balloon angioplasty, we summarize Grüntzig’s life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter’s first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig’s former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated

  18. Comparative Efficacy of Pulse-Spray Thrombolysis and Angioplasty Versus Surgical Salvage Procedures for Treatment of Recurrent Occlusion of PTFE Dialysis Access Grafts

    SciTech Connect

    Polak, Joseph F.; Berger, Markus F.; Pagan-Marin, Heriberto; Aruny, John E.; Meyerovitz, Michael F.

    1998-07-15

    Purpose: To compare the efficacy of surgery versus pulse-spray thrombolysis and angioplasty in patients with recurrent thrombosis of polytetrafluoroethylene (PTFE) dialysis access grafts. Methods: We analyzed 96 consecutive interventions for thrombosed PTFE dialysis access grafts in 18 patients. Primary patency after thrombolysis and angioplasty (n= 25) was compared with primary patency following thrombectomy alone (n= 50) or thrombectomy followed by graft revision (n= 21) using life-table analysis. A Cox proportional hazards model that accounted for graft age and number of previous interventions was used to generate the relative risk for recurrent occlusion following therapy. Results: Life-table analysis showed that patency after thrombolysis and angioplasty was greater than that following thrombectomy alone (p= 0.02). After accounting for the age of the graft and the number of previous interventions (average six per patient), the relative risk for recurrent occlusion [3.0; 95% confidence intervals (CI): 1.5, 6.4] was greater for thrombectomy alone than for thrombolysis/angioplasty [0.6; CI = 0.3, 1.3]. The relative risks of repeat occlusion following thrombolysis/angioplasty [0.6; CI = 0.3, 1.3] and thrombectomy/surgical revision [1.0; CI = 0.5, 1.7] were similar. Conclusion: Outcome data from our retrospective study on recurrent thrombosis of PTFE dialysis access grafts suggest that thrombolysis/angioplasty is superior to thrombectomy alone, and equivalent to thrombectomy/surgical revision.

  19. Lineare und verzweigte Blockcopolymere aus Polypeptiden und synthetischen Polymeren

    NASA Astrophysics Data System (ADS)

    Kukula, Hildegard

    2001-07-01

    Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Eigenschaften von linearen und verzweigten amphiphilen Polypeptid-Blockcopolymeren. Die Frage nach dem Einfluss der Topologie und Konformation der Blockcopolymere auf die supramolekularen und kolloidalen Eigenschaften bildete einen wichtigen Aspekt bei den Untersuchungen. Die Blockcopolymere wurden nach einem mehrstufigen Reaktionsschema durch Kombination von anionischer und ringöffnender Polymerisation von Aminosäuren-N-Carboxyanhydriden (NCA) synthetisiert. Die Untersuchung der Polypeptid-Blockcopolymere hinsichtlich ihres Aggregationsverhaltens in fester Phase sowie in verdünnter wässriger Lösung erfolgte mittels Streumethoden (SAXS, WAXS, DLS) sowie abbildender Methoden (TEM). Durch Einsatz der Blockcopolymere als polymere Stabilisatoren in der Emulsionspolymerisation wurden Oberflächen funktionalisierte Latizes erhalten. Als Beispiel für eine pharmazeutische Anwendung wurden bioverträgliche Polypeptid-Blockcopolymere als Wirkstoff-Trägersysteme in der Krebstherapie eingesetzt. This work describes the synthesis and characterization of linear and branched polypeptide block copolymers having amphiphilic character. The studies focused on the impact of the block copolymers' conformation and architecture on the supramolecular and colloidal properties. The polypeptide block copolymers were prepared in a multi-step process involving the anionic synthesis of (poly)amino-functional polymers (polystyrene and polybutadiene) which where used as macroinitiators for the ring-opening polymerization of N-carboxyanhydrides (NCA) of protected a-aminoacids. Supramolecular structures of the block copolymers in the solid state as well as in diluted aqueous solution were investigated using scattering (SAXS, WAXS, DLS) and microscopic (TEM) methods. Both linear and branched polypeptide block copolymers were used as polymeric stabilizers in the emulsion polymerization of styrene to yield polypeptide

  20. Dynamische Motorvermessung mit verschiedenen Methoden und Modellen

    NASA Astrophysics Data System (ADS)

    Schreiber, Alexander

    Die stark zunehmenden gesetzlichen und wirtschaftlichen Vorgaben zur Senkung von Kraftstoffverbrauch und Abgasemissionen stellen große Anforderungen an die weitere Entwicklung von Benzin- und Dieselmotoren. Hierbei sind grundlegende Fortschritte durch Konstruktion und auslegungsbedingte Maßnahmen im Bereich der Einspritzung, Gemischaufbereitung, Aufladung, Brennverfahren und Abgasnachbehandlung zu erreichen. Ein wesentlicher Teil dieser Verbesserungen wird jedoch durch eine Zunahme von Variabilitäten erreicht wie z.B. verstellbaren Vor-, Haupt- und Nacheinspritzungen, variablem Raildruck, variablen Nockenwellensteuerwinkeln, Ventilhüben, Drall-/Tumbleklappen sowie verstellbaren Abgasturbinen, Abgasrückführströmen und Abgasnachbehandlungssystemen. Dadurch steigt die Zahl der Stellglieder (Aktoren) stark an. Hinzu kommen zusätzliche Sensoren wie z.B. für Luftzahl, NOx, Brennraumdruck, Abgastemperatur und Abgasdruck. Deshalb nimmt der Umfang der Steuerungs-, Regelungs- und Diagnosefunktionen in der Motorelektronik (ECU) stark zu. Bild 7-1 zeigt als Beispiel den Signalfluss für die gesteuerten und geregelten Größen eines Dieselmotors in einer beispielhaften Prüfstandsumgebung.

  1. Holmium:YAG laser coronary angioplasty: quantitative angiography and clinical results in a large experience of a single medical center

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Clinical experience with the mid IR holmium:YAG laser in a single medical center (St. Paul Ramsey Medical Center, University of Minnesota Medical School, St. Paul, MN) includes 112 patients who underwent holmium laser coronary angioplasty. Utilizing a unique lasing technique; `pulse and retreat,' we applied this laser to thrombotic and nonthrombotic lesions in patients presenting with unstable angina, stable angina, and acute myocardial infarction. A very high clinical success and very low complication rates were achieved. Holmium:YAG laser is effective and safe therapy for patients with symptomatic coronary artery disease. Unlike excimer lasers, the clinical success, efficacy and safety of holmium laser angioplasty is not compromised when thrombus is present.

  2. Heme oxygenase-1 alleviates cigarette smoke-induced restenosis after vascular angioplasty by attenuating inflammation in rat model.

    PubMed

    Ni, Leng; Wang, Zhanqi; Yang, Genhuan; Li, Tianjia; Liu, Xinnong; Liu, Changwei

    2016-03-14

    Cigarette smoke is not only a profound independent risk factor of atherosclerosis, but also aggravates restenosis after vascular angioplasty. Heme oxygenase-1 (HO-1) is an endogenous antioxidant and cytoprotective enzyme. In this study, we investigated whether HO-1 upregulating by hemin, a potent HO-1 inducer, can protect against cigarette smoke-induced restenosis in rat's carotid arteries after balloon injury. Results showed that cigarette smoke exposure aggravated stenosis of the lumen, promoted infiltration of inflammatory cells, and induced expression of inflammatory cytokines and adhesion molecules after balloon-induced carotid artery injury. HO-1 upregulating by hemin treatment reduced these effects of cigarette smoke, whereas the beneficial effects were abolished in the presence of Zincprotoporphyrin IX, an HO-1 inhibitor. To conclude, hemin has potential therapeutic applications in the restenosis prevention after the smokers' vascular angioplasty. PMID:26809138

  3. Does the method of transluminal coronary revascularisation influence re-stenosis? Balloon angioplasty, atherectomy and stents compared.

    PubMed

    Foley, D P; Keane, D; Serruys, P W

    1995-01-01

    Luminal renarrowing after successful coronary angioplasty is now recognised as a continuously distributed process which is determined largely by the extent of luminal increase achieved at angioplasty. In this study an alternative analytical approach is applied to determine whether luminal renarrowing following coronary intervention is related to the mechanism of luminal increase (ie by balloon, by atherectomy, by a self-expanding stainless steel mesh stent, or by a balloon-expandable tantalum coil stent). The results confirm the known proportional relationship between luminal renarrowing during follow-up and luminal improvement at intervention, regardless of the device used. However, significant differences were observed between the devices, which may reflect device-specific characteristics of the hyperplastic response to vessel injury and may have clinical implications. PMID:7742199

  4. Angioplasty or Stenting in Adult Coarctation of the Aorta? A Retrospective Single Center Analysis Over a Decade

    SciTech Connect

    Macdonald, Sumaira Thomas, Steven M.; Cleveland, Trevor J.; Gaines, Peter A.

    2003-08-15

    For over 11 years, endovascular treatment by angioplasty (PTA) alone or stenting of adult coarctation at a single center was evaluated. We retrospectively reviewed 28 consecutive patients (31 interventions), median age 25 years, treated between 1991 and 2002, 20 of whom had native coarctation. Thirteen patients had PTA alone (16 procedures) (10 'kissing balloon' angioplasty comprising 12 interventions, and 3 single balloon angioplasty comprising 4 interventions) and 15 patients were stented(15 procedures), including 6 secondary and 9 primary stents. There were no procedural or 30-day complications. For the whole group, the median follow-up was 6.6 years (range 1-10 years). In the PTA group, median follow-up was 9 years (range 3-10) and in the stenting group it was 3 years (range 1-5). There were 9 restenoses in the PTA group (6 after 'kissing balloons' and 3 after single balloon) comprising 56% of the angioplasties (9/16 procedures). There was 1 restenosis in the stenting group diagnosed at computed tomography (CT). The patient was clinically well. For the whole group there were significant reductions in systolic blood pressure (BP) (p 0.0003), diastolic BP (p = 0.004) and number of drugs per patient (p = 0.045) at latest follow-up post-treatment. Five patients discontinued therapy.Analysis of the groups revealed that the reduction of systolic and diastolic BP and number of drugs did not reach statistical significance in the PTA group but were significant in the stent group. The endovascular management of adult coarctation is safe. Stents may be more effective than PTA alone but longer-term follow-up of stents is required.

  5. Below-the-ankle Angioplasty and Stenting for Limb Salvage: Anatomical Considerations and Long-term Outcomes

    SciTech Connect

    Katsanos, Konstantinos Diamantopoulos, Athanasios; Spiliopoulos, Stavros; Karnabatidis, Dimitris; Siablis, Dimitris

    2013-08-01

    PurposeTo report the long-term angiographic and clinical results in a series of below-the-ankle (BTA) angioplasty procedures and to present some biomechanical issues related to the unique anatomical geometry of the ankle.MethodsWe performed a retrospective analysis of BTA angioplasty procedures. Clinical end points included technical success, patient mortality, salvage of the treated foot, and repeat target lesion revascularization. Imaging end points included primary patency, binary restenosis of the target lesion at the 50 % threshold, and stent integrity (stent fracture, deformation, or collapse). Univariate subgroup analysis was performed.ResultsIn total, 40 limbs in 37 patients (age 73.5 {+-} 8.2 years) with critical limb ischemia were included and 42 inframalleolar lesions (4.2 {+-} 1.4 cm) were analyzed. Technical success was achieved in 95.2 % (40 of 42). Provisional stent placement was performed in 45.2 % (19 of 42). Two patients died, and two major amputations occurred up to 3 years. At 1 year, overall primary vessel patency was 50.4 {+-} 9.1 %, lesion binary restenosis rate was 64.1 {+-} 8.3 %, and repeat intervention-free survival was 93.6 {+-} 4.3 % according to life table analysis of all treated lesions. Pairwise subgroup analysis showed that BTA self-expanding stents were associated with significantly higher restenosis and poorer primary patency compared to plain balloon angioplasty or sirolimus-eluting balloon-expandable stents. Significant deformation and/or fracture of balloon-expandable stents placed BTA were identified in five of 11. Dynamic imaging showed that the dorsalis pedis artery is kinked during foot dorsiflexion, whereas the distal posterior tibial artery is kinked during plantar flexion of the foot.ConclusionBTA angioplasty for critical limb ischemia treatment is safe and feasible with satisfactory long-term results. BTA stent placement must be reserved for bailout indications.

  6. [Intraoperative iliac angioplasty and distal revascularization: is it an efficacious method in the high-risk patient?].

    PubMed

    Adovasio, R; Chiarandini, S; Ziani, B; Pozzi Mucelli, R

    1992-01-01

    The fact that iliac femoro-popliteal areas are both simultaneously interested in some high risk patients, frequently is cause of several problems in the indication of the surgical treatment. So, we have decided to practice an iliac Angioplasty peroperatively as a method of iliac revascularization in association with the surgical repairment of the femoro-popliteal area. Results of 20 patients with 23 surgical procedures during a period of two years is reported. PMID:1285579

  7. Patency of Wallstents Placed at the Venous Anastomosis of Dialysis Grafts for Salvage of Angioplasty-Induced Rupture

    SciTech Connect

    Rajan, Dheeraj K.; Clark, Timothy W.I.

    2003-06-15

    Purpose: To retrospectively evaluate the patency of Wallstents placed at the venous anastomosis of polytetraflouroethylene (PTFE) hemodialysis grafts to preserve function following angioplasty-induced rupture. Methods: The charts of all patients who underwent percutaneous angioplasty of functioning hemodialysis PTFE grafts between September 1997 and September 2001 were retrospectively reviewed. A total of 414 angioplasties were performed. Nine cases of rupture at the venousanastomosis managed with stent placement were identified (7 women, 2 men). Two grafts were loop grafts, seven grafts were straight grafts. All stents placed were Wallstents; six stents were 8 x 40 mm, the remaining three were 8 x 20 mm, 8 x 60 mm and 10 x 42mm. Average follow-up was 13 months. Results: Technical and clinical success of stent placement was 100%. The primary patencyrates ({+-}SE) of stents placed at the venous anastomosis were 88% (12%) at 30 days, 63% (17%) at 90 days, 33% (18%) at 180 days and 17% (15%) at 360 days. The secondary patency rates ({+-}SE) were 89% (11%) at 90 days, 76% (15%) at 180 days and 69% (23%) (6 stentspatent) at 360 days. During follow-up, one graft was removed because of infection, one patient died and another was lost to follow-up. A single minor complication of a puncture site hematoma occurred (11%) with no major complications. Conclusions: This small retrospective series suggests that Wallstent placement following angioplasty-induced venous anastomotic rupture is effective for preserving dialyzable flow in hemodialysis grafts. Patency is comparable to that of stents placed for reasons other than rupture.

  8. Randomized Trial of the SMART Stent versus Balloon Angioplasty in Long Superficial Femoral Artery Lesions: The SUPER Study

    SciTech Connect

    Chalmers, Nicholas; Walker, Paul T.; Belli, Anna-Maria; Thorpe, Anthony P.; Sidhu, Paul S.; Robinson, Graham; Ransbeeck, Mariella van

    2013-04-15

    To determine whether primary stenting reduces the rate of restenosis compared with balloon angioplasty alone in the endovascular treatment of long superficial femoral artery lesions; and to assess the effect of treatment on quality of life. A total of 150 patients with superior femoral artery occlusion or severe stenosis of 5-22 cm length from 17 UK centers were randomized to either primary stenting with the SMART stent or balloon angioplasty (i.e., percutaneous transluminal angioplasty, PTA). Bailout stent placement was permitted in case of inadequate result from PTA. The primary end point was restenosis measured by duplex ultrasound at 1 year. Quality-of-life assessments were performed by the EuroQol (EQ)-5D questionnaire. Mean lesion length was 123.0 mm in the stent group and 116.8 mm in the PTA group. A total of 140 (93.3 %) of 150 had total occlusions. At 12 months' follow-up, restenosis measured by Duplex ultrasound was not significantly different between the stent and PTA groups by intention-to-treat or as-treated analyses: 47.2 versus 43.5 % (p = 0.84) and 40.8 versus 46.7 % (p = 0.68), respectively. There were fewer target lesion revascularizations in patients randomized to stenting, but this did not reach statistical significance (12.5 vs. 20.8 %, p = 0.26). There was no difference in the rate of amputation. Patients in both groups reported improved quality of life. Primary stenting of long lesions in predominantly occluded superficial femoral arteries does not reduce the rate of binary restenosis compared with balloon angioplasty and bailout stenting. Both treatment strategies conferred a meaningful and sustained improvement to the quality of life of patients with severe superficial femoral artery disease.

  9. Radiotherapy-Related Axillary Artery Occlusive Disease: Percutaneous Transluminal Angioplasty and Stenting. Two Case Reports and Review of the Literature

    SciTech Connect

    Farrugia, M. Gowda, K.M.S.; Cheatle, T.R.; Ashok, T.P.

    2006-12-15

    Radiotherapy-related axillary artery occlusive disease is a relatively rare condition. This complication is usually encountered in patients with breast carcinoma treated by radiotherapy and might be frequently concealed by the presence of lymphoedema. We discuss this rare complication of radiotherapy treatment for breast cancer and present two cases and their successful treatment by a modified percutaneous transluminal angioplasty and stenting technique. A review of literature on the subject is also presented.

  10. Recovery of regional myocardial dysfunction after successful coronary angioplasty early after a non-Q wave myocardial infarction

    SciTech Connect

    Suryapranata, H.; Serruys, P.W.; Beatt, K.; De Feyter, P.J.; van den Brand, M.; Roelandt, J. )

    1990-08-01

    More aggressive therapy has been suggested for patients who have a non-Q wave myocardial infarction (MI) because of the frequency of subsequent unstable angina, recurrent MI, and high mortality rate compared to patients with Q wave MI. The present study was undertaken to investigate the effect of coronary angioplasty on regional myocardial function of the infarct zone in patients with angina early after a non-Q wave MI. The study population consisted of 36 patients undergoing successful coronary angioplasty within 30 days of a non-Q wave MI, in whom sequential left ventricular angiograms of adequate quality were obtained before the initial procedure and at follow-up angiography. The global ejection fraction increased significantly from 60 +/- 9% to 67 +/- 6% (p = 0.0003). This significant increase in the global ejection fraction was primarily due to a significant improvement in the regional myocardial function of the infarct zone. The results of the present study show not only that ischemic attacks early after a non-Q wave MI may lead to prolonged regional myocardial dysfunction but more important that this depressed myocardium has the potential to achieve normal contraction after successful coronary angioplasty.

  11. Clinical efficacy and scintigraphic evaluation of post-coronary bypass patients undergoing percutaneous transluminal coronary angioplasty for recurrent angina pectoris

    SciTech Connect

    Reed, D.C.; Beller, G.A.; Nygaard, T.W.; Tedesco, C.; Watson, D.D.; Burwell, L.R.

    1989-01-01

    The efficacy of percutaneous transluminal angioplasty in improving recurrent anginal symptoms and myocardial perfusion after coronary artery bypass graft surgery was assessed prospectively in 55 patients, of whom 50 had an initial angiographic and clinical success. Although 80% of those successfully dilated were initially free of angina at 23 +/- 11 months of follow-up, one half of these patients had recurrent angina. Although only 48% of the patient cohort had complete relief of angina, 94% had less angina than before dilatation and 86% were able to decrease antianginal medications. Fifteen patients with persistent or recurrent angina had from one to five repeat dilatations. After angioplasty, lung thallium uptake, the extent of abnormal scan segments, and the magnitude of redistribution in dilated lesions were significantly reduced (n = 24 patients). Redistribution defects were seen in 38% of patients on postangioplasty scans. All were associated with subsequent angina. Of various clinical, angiographic, exercise, and thallium-201 scan variables, only the presence of delayed redistribution was an independent predictor of recurrent angina. Restenosis was the most common underlying cause for this exercise-induced perfusion defect. Thus percutaneous coronary angioplasty performed as primary therapy for recurrent angina after bypass surgery is moderately successful in long-term follow-up for the amelioration of symptoms and enhancement of regional myocardial perfusion.

  12. Early intervention in acute myocardial infarction: significance for myocardial salvage of immediate intravenous streptokinase therapy followed by coronary angioplasty

    SciTech Connect

    Miller, H.I.; Almagor, Y.; Keren, G.; Chernilas, J.; Roth, A.; Eschar, Y.; Shapira, I.; Shargorodsky, B.; Berenfeld, D.; Laniado, S.

    1987-03-01

    Sixteen patients with acute myocardial infarction underwent treatment with streptokinase up to 3 hours after the onset of chest pain. Nine patients (group I) received streptokinase within 1 hour of the onset of pain, and seven patients (group II) received it within 2 to 3 hours. All underwent multigated radionuclide ventriculography after streptokinase therapy and 1 week later. Percutaneous transluminal coronary angioplasty of the infarct artery was performed within 24 hours in all patients. An effort-limited treadmill stress test was performed before discharge. There was no mortality or serious complication. Mean peak total creatine kinase was 521 +/- 289 mU/ml in group I, and 1,614 +/- 709 mU/ml in group II (p less than 0.05). The mean initial left ventricular ejection fraction was 47 +/- 11% in group I and 37 +/- 10% in group II. After early angioplasty (within 24 hours) and at 1 week recovery, left ventricular ejection fraction increased to 53 +/- 9% in group I (p less than 0.05) and to 40 +/- 7% in group II (p = NS). Seven of the nine patients in group I had normal radionuclide ventriculograms at discharge compared with none of the seven patients in group II. Thrombolytic therapy administered less than 1 hour after the onset of symptoms of acute myocardial infarction followed by angioplasty of the infarct artery results in preservation of left ventricular function, whereas therapy given after 2 hours has only a limited effect.

  13. [Ultrasound coronary angioplasty: state of the art and new clinical aspects].

    PubMed

    Rosenschein, U; Budde-Schwartzman, B

    1997-12-01

    Therapeutic ultrasound was shown to ablate thrombi and to disrupt atherosclerotic plaques in vitro and recently to recanalize occluded coronary arteries in acute myocardial infarction (AMI). The goal of this article is to update collective experience and to weigh the promising and unresolved aspects of this newly developed technology and its clinical results. As therapeutic ultrasound was for long known a synonym for lithotripsy of calculi diseases, it lastly received high attention as a catheter-based ultrasound method to ablate thrombi and disrupt atherosclerotic plaques in interventional cardiology (Figure 1). The effect of therapeutic ultrasound to ablate selectively pathological tissue depends on its bioselectivity for elastic fibers: After ultrasound sonication, healthy tissue-rich in elastin and collagen-including arterial wall remains intact whereas thrombus and plaque with their minimal elastic support are found to be highly susceptible to ablation. Our catheter for coronary ultrasound thrombolysis (Figure 2) consists of a solid metal probe and is connected to a piezo-electric transducer at its proximal end. The distal part ends in a three-wire flexible segment with a 1.6 mm tip ball to guarantee maximal wire flexibility and optimal transmission of ultrasound energy. The initial in vitro studies resulted in a fundamental understanding of the destructive effect of ultrasound on tissue based on 4 factors: mechanical vibration, thermal effects, microcurrents, and cavitation. The first studies on human peripheral vessels were published in 1991 being performed during femoral bypass surgery on occluded and partially obstructed arteries. The procedure was performed without perforation, no adverse side effects emerged, restenosis rate was 20%. The clinical application of coronary ultrasound angioplasty was initiated in 1991; Siegel published his data on 44 patients. In his study, 30 patients with chronic atherosclerotic occlusive lesions and 14 with unstable or

  14. Cutting-balloon angioplasty before drug-eluting stent implantation for the treatment of severely calcified coronary lesions

    PubMed Central

    Tang, Zhe; Bai, Jing; Su, Shao-Ping; Wang, Yu; Liu, Mo-Han; Bai, Qi-Cai; Tian, Jin-Wen; Xue, Qiao; Gao, Lei; An, Chun-Xiu; Liu, Xiao-Juan

    2014-01-01

    Background Severely calcified coronary lesions respond poorly to balloon angioplasty, resulting in incomplete and asymmetrical stent expansion. Therefore, adequate plaque modification prior to drug-eluting stent (DES) implantation is the key for calcified lesion treatment. This study was to evaluate the safety and efficacy of cutting balloon angioplasty for severely calcified coronary lesions. Methods Ninety-two consecutive patients with severely calcified lesions (defined as calcium arc ≥ 180° calcium length ratio ≥ 0.5) treated with balloon dilatation before DES implantation were randomly divided into two groups based on the balloon type: 45 patients in the conventional balloon angioplasty (BA) group and 47 patients in the cutting balloon angioplasty (CB) group. Seven cases in BA group did not satisfactorily achieve dilatation and were transferred into the CB group. Intravascular ultrasound (IVUS) was performed before balloon dilatation and after stent implantation to obtain qualitative and quantitative lesion characteristics and evaluate the stent, including minimum lumen cross-sectional area (CSA), calcified arc and length, minimum stent CSA, stent apposition, stent symmetry, stent expansion, vessel dissection, and branch vessel jail. In-hospital, 1-month, and 6-month major adverse cardiac events (MACE) were reported. Results There were no statistical differences in clinical characteristics between the two groups, including calcium arc (222.2° ± 22.2° vs. 235.0° ± 22.1°, P = 0.570), calcium length ratio (0.67 ± 0.06 vs. 0.77 ± 0.05, P = 0.130), and minimum lumen CSA before PCI (2.59 ± 0.08 mm2 vs. 2.52 ± 0.08 mm2, P = 0.550). After stent implantation, the final minimum stent CSA (6.26 ± 0.40 mm2 vs. 5.03 ± 0.33 mm2; P = 0.031) and acute lumen gain (3.74 ± 0.38 mm2 vs. 2.44 ± 0.29 mm2, P = 0.015) were significantly larger in the CB group than that of the BA group. There were not statistically differences in stent expansion, stent symmetry

  15. Site-targeted acoustic contrast agent detects molecular expression of tissue factor after balloon angioplasty

    NASA Astrophysics Data System (ADS)

    Hall, Christopher S.; Abendschein, Dana R.; Scherrer, David E.; Scott, Michael J.; Marsh, Jon N.; Wickline, Samuel A.; Lanza, Gregory M.

    2000-04-01

    Complex molecular signaling heralds the early stages of pathologies such as angiogenesis, inflammation, and cellular responses to mechanically damaged coronary arteries after balloon angioplasty. In previous studies, we have demonstrated acoustic enhancement of blood clot morphology with the use of a nongaseous, ligand-targeted acoustic nanoparticle emulsion delivered to areas of thrombosis both in vitro and in vivo. In this paper, we characterize the early expression of tissue factor which contributes to subsequent arterial restenosis. Tissue factor is a 42kd glycoprotein responsible for blood coagulation but also plays a well-described role in cancer metastasis, angiogenesis, and vascular restenosis. This study was designed to determine whether the targeted contrast agent could localize tissue factor expressed within the wall of balloon-injured arteries. Both carotid arteries of five pigs (20 kg) were injured using an 8 X 20 mm angioplasty balloon. The carotids were treated in situ with a perfluorocarbon nanoparticle emulsion covalently complexed to either specific anti-tissue factor polyclonal F(ab) fragments (treatment) or non-specific IgG F(ab) fragments (control). Intravascular ultrasound (30 MHz) images of the arteries were obtained before and after exposure to the emulsions. Tissue- factor targeted ultrasonic contrast agent acoustically enhanced the subintima and media at the site of balloon- induced injury compared with control contrast arteries (p less than 0.05). Immunohistochemical staining confirmed the presence of increased tissue factor at the sites of acoustic enhancement. Binding of the targeted agents was demonstrated in vitro by scanning electron microscope images of cultured smooth muscle cells that constitutively express tissue factor. This study demonstrates the concept of molecular imaging and localization of carotid arteries' tissue factor in vivo using a new, nanoparticulate emulsion. Enhancement of the visualization of the molecular

  16. Identification of patients at high risk for adverse coronary events while awaiting routine coronary angioplasty.

    PubMed Central

    Chester, M.; Chen, L.; Kaski, J. C.

    1995-01-01

    BACKGROUND--Identification of patients at risk for progression of coronary stenosis and adverse clinical events while awaiting coronary angioplasty is desirable. OBJECTIVE--To determine the standard clinical or angiographic variables, or both, present at initial angiography associated with the development of adverse coronary events (unstable angina, myocardial infarction, and angiographic total coronary occlusion) in patients awaiting routine percutaneous transluminal coronary angioplasty (PTCA). PATIENTS AND METHODS--Consecutive male patients on a waiting list for routine PTCA. Routine clinical details were obtained at initial angiography. Stenosis severity was measured using computerised angiography. OUTCOME MEASURES--Development of one or more of myocardial infarction, unstable angina, or angiographic total coronary occlusion while awaiting PTCA were recorded as an adverse event. RESULTS--Some 214 of 219 patients underwent a second angiogram. One had a fatal myocardial infarction and four (2%) were lost to follow up. Fifty patients (23%) developed one or more adverse events (myocardial infarction five, unstable angina 35, total coronary occlusion 23) at a median (range) interval of 8 (3-25) months. Twenty (57%) of the 35 patients with unstable angina developed adverse events compared with 30 (17%) of the 180 with stable angina (P = 0.0001). Plasma triglyceride concentration was 2.6 (1.2) mmol/l in patients with adverse coronary events compared with 2.2 (1.1) mmol/l in those without such events (P < 0.05). Patients with adverse events were younger than those without (54 (9) years v 58 (9) years, P < 0.01). The relative risk of an adverse event in patients with unstable angina and increased plasma triglyceride concentrations was 6.9 compared with those presenting with stable angina and a normal triglyceride concentration (P < 0.02). CONCLUSIONS--The study shows that adverse events are not uncommon in patients awaiting PTCA. Patients at high risk for adverse events

  17. Thermal characteristics of sapphire contact probe delivery systems for laser angioplasty.

    PubMed

    Ashley, S; Brooks, S G; Gehani, A A; Kester, R C; Rees, M R

    1990-01-01

    Contact probes made from synthetic sapphire crystal, designed for general laser surgery, are currently being evaluated for use in laser angioplasty. Their mode of action and safety in the context of arterial recanalisation is unknown, particularly with respect to the degree of probe and catheter heating. Infrared thermal imaging was used to investigate the surface temperature rise of various rounded sapphire probes during emission of continuous wave Nd-YAG (1,064 nm) laser energy. Catheter safety was addressed by analyzing the temperature of the metal interface between the optical fiber and sapphire, as well as the catheter proximal to this junction. Transmission of Nd-YAG energy through each probe was also measured. Five rounded probes of 1.8-3.0 mm diameter (three supplied by Surgical Laser Technologies [SLT], two by Living Technology [LT]), along with their respective optical catheters, were compared. There was a large temperature gradient between the front and rim of the probes. The maximum surface temperature rise of the sapphire (at 20 W, 5-second exposure) was 314-339 degrees C (SLT) and 90-108 degrees C (LT) [P less than 0.001, 3-way ANOVA]. The reason for this difference may be related to "crazing" of the front surface of the SLT sapphires. At all energy levels sapphire temperatures were considerably lower than attained by metal laser thermal angioplasty probes. Forward transmission was slightly higher in the SLT probes (75-85%) than the LT sapphires (54-69%). With fiber perfusion at 2 ml/minute, a minor degree of heating of the metal sapphire holders was recorded (maximum rise 35 degrees C), but heating of the catheter proximal to this was negligible. Therefore, it would appear that the risk of tip detachment or arterial injury due to heating of the connecting metal interface is extremely low. Without perfusion, however, there was a greater degree of interface heating in the LT delivery system suggestive of more laser backscattering by these sapphires

  18. Thermal and optical behavior of sapphire fiber tips for laser angioplasty

    NASA Astrophysics Data System (ADS)

    Ashley, Simon; Brooks, Stephen G.; Gehani, Abdurrazak A.; Kester, Ralph C.; Rees, Michael R.

    1990-07-01

    Atraumatic rounded contact probes made from artificial sapphire crystal were developed for general laser surgery and are currently being evaluated for use in percutaneous laser angioplasty utilising continuous wave (cw) Nd-YAG energy (1064nm). The thermal and optical characteristics of five different types of rounded sapphire probe [Surgical Laser Technologies (SLT) - SMTR (1.8mm), MTh (2.2mm), MTRL (3.0mm); Living Technology - LT (2.2mm), OS (2.2mm)] were investigated and related to efficiency of contact ablation of arterial wall in vitro. The sapphire probes were mounted on catheters containing a 0.6 mm quartz optical fiber, coupled to a cw Nd-YAG laser. All probes produced a similar beam profile but there was some variation in their forward transmission of energy (54-85%).Probe heating occurs due to energy absorption within the sapphire and was measured in air by infrared thermography. There was a high temperature gradient from the front surface of the sapphires to the probe rim. But, at energy settings used clinically (10 J pulses, 10 Watts for 1 second) the SMTR, MTR, and MTRL probes exhibited a higher mean temperature rise (63-74 C) than the OS and LT probes (20 C) [3-way ANOVA p

  19. Role of intracoronary thrombus in acute complications during percutaneous transluminal coronary angioplasty.

    PubMed

    Arora, R R; Platko, W P; Bhadwar, K; Simpfendorfer, C

    1989-04-01

    Coronary angiograms from 2,372 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) were retrospectively reviewed for the presence of intracoronary thrombus (ICT) before dilatation. Patients with evolving acute myocardial infarction and those receiving thrombolytic therapy were excluded from analysis. Coronary artery thrombus was present in 126 patients (6%) (group 1). When compared to 2,246 patients (group 2) without ICT, group 1 had a higher incidence of unstable angina, 74% vs. 66% (less than 0.06), previous myocardial infarction, 59% vs. 37% (P less than .0001), and history of a recent myocardial infarction, 28% vs. 9% (P less than .0001). Patients with predilatation intracoronary thrombus had a higher risk for acute occlusion, 6% vs. 2% (P less than .002); however, the incidence of emergency coronary bypass surgery and myocardial infarction was similar in both groups. Therefore, the presence of predilatation intracoronary thrombus heralds an increased risk of acute occlusion, but not myocardial infarction or emergency coronary artery bypass surgery. PMID:2523243

  20. Percutaneous Aspiration Thrombectomy for the Treatment of Arterial Thromboembolic Occlusions Following Percutaneous Transluminal Angioplasty

    SciTech Connect

    Schleder, Stephan; Diekmann, Matthias; Manke, Christoph; Heiss, Peter

    2015-02-15

    PurposeThis study was designed to evaluate the technical success and the early clinical outcome of patients undergoing percutaneous aspiration thrombectomy (PAT) for the treatment of arterial thromboembolism following percutaneous infrainguinal transluminal angioplasty (PTA).MethodsIn this single-center study, during a period of 7 years retrospectively, 47 patients (22 male, 47 %) with a mean age of 73 (range 53–96) years were identified in whom PAT was performed for the treatment of thromboembolic complications of infrainguinal PTA. Primary technical success was defined as residual stenosis of <50 % in diameter after sole PAT, whereas secondary technical success was defined as residual stenosis of <50 % in diameter after PAT and additional PTA and/or stenting. Clinical outcome parameters (e.g., need for further intervention, minor/major amputation) were evaluated for the 30-day postinterventional period.ResultsPrimary technical success was achieved in 64 % of patients (30/47); secondary technical success was obtained in 96 % of patients (45/47). Clinical outcome data were available in 38 patients. In 87 % of patients (33/38), there was no need for further intervention within the 30-day postinterventional period. In three patients, minor amputations were conducted due to preexisting ulcerations (Rutherford Category 5 respectively).ConclusionsPAT enables endovascular treatment of iatrogenic thromboembolic complications after PTA with good technical and early clinical results and minimal morbidity.

  1. Haemodynamic observations during percutaneous transluminal coronary angioplasty in the presence of synchronised diastolic coronary sinus retroperfusion.

    PubMed Central

    Beatt, K J; Serruys, P W; de Feyter, P; van den Brand, M; Verdouw, P D; Hugenholtz, P G

    1988-01-01

    Animal studies have demonstrated that synchronised coronary sinus retroperfusion with arterial blood can provide effective perfusion of ischaemic myocardium. Preliminary clinical studies have shown that the technique can also be used with safety in human beings, and in the present study its effectiveness was assessed in three patients undergoing repeated coronary artery occlusions during percutaneous transluminal coronary angioplasty. Arterial blood was removed via an 8F catheter positioned in the femoral artery and delivered by a retroperfusion pumping system to a 7F retroperfusion balloon catheter positioned in the anterior cardiac vein. Ischaemia-related indices were monitored both before and during coronary sinus retroperfusion. These indices included high fidelity left ventricular pressure recordings and pressure derived indices (including velocities of isovolumic contraction and relaxation), as well as electrocardiographic changes and symptoms. Analysis of these variables showed that the ischaemic changes induced during coronary artery occlusion were not prevented by this type of coronary sinus retroperfusion. There was no major complication in any of the patients. It may be that adaptation of the technique or the use of alternative end points will establish a benefit, but further modifications of the delivery system are necessary for effective clinical use. Images Fig 1 PMID:2963657

  2. Ablation of chronic total occlusions using kilohertz-frequency mechanical vibrations in minimally invasive angioplasty procedures.

    PubMed

    McGuinness, G B; Wylie, M P; Gavin, G P

    2010-01-01

    Certain minimally invasive cardiology procedures, such as balloon angioplasty and stent implantation, critically require that the site of an arterial blockage be crossed by an intraluminal guidewire. Plaques resulting in near or totally occluded arteries are known as chronic total occlusions, and crossing them with conventional guidewires is a significant challenge. Among the most promising proposed solutions is the delivery of high-power, low-frequency ultrasonic vibrations to the occlusion site via an intraluminal wire waveguide. The vibrating distal tip of the ultrasound wire waveguide is used to transmit energy to the surrounding plaques, tissues, and fluids to ablate or weaken atherosclerotic plaque. Potential mechanisms of interaction with the plaque and adjacent fluids identified in the literature include: (i) direct contact with the waveguide distal tip, (ii) subcavitational acoustic fluid pressure fluctuations, (iii) cavitation, and (iv) acoustic streaming. We summarize developments in this area over more than two decades, describing experimental methods for device performance characterization, preclinical tests, early clinical investigations, and, later, full clinical trials. The article also reviews theoretical foundations and numerical models suitable for device design and analysis. Finally, important issues for future research and for the development of this technology will be considered. PMID:21303322

  3. Diabetic foot wounds in haemodialysis patients: 2-year outcome after percutaneous transluminal angioplasty and minor amputation.

    PubMed

    Matsuzaki, Kyoichi; Miyamoto, Akira; Hakamata, Naohiro; Fukuda, Masahiro; Yamauchi, Yasutaka; Akita, Takako; Kuhara, Ryoji; Tezuka, Shingo

    2012-12-01

    Critical limb ischaemia (CLI) is known to be associated with high mortality. In some patients, surgery cannot be performed due to high risk of perioperative death and complications. In other cases, there is only pain at rest but no wound. Therefore, it is difficult to accurately predict the prognosis of individual patients. We examined the prognosis of CLI cases in which therapeutic footwear was made for ambulation after wounds healed. The subjects were 31 haemodialysis patients with diabetic foot wounds, which were treated with percutaneous transluminal angioplasty and minor amputation. The subjects were 22 men and 9 women. Female patients were significantly older than male patients (P = 0.046). Two-year postoperative outcomes were survival in 19 patients and death in 12 patients. Eight of twelve deceased patients had a history of coronary intervention. There were 8 deaths among 13 patients with such history, indicating a marginally significant increase in the mortality rate (P = 0.060). Re-amputation was performed in 6 of 19 patients who survived. Two years postoperatively, 41.9% of patients overall survived without re-amputation. It is important to increase the number of cases for further study to improve the well-being of CLI patients and to examine medical economics. PMID:23095148

  4. [Percutaneous transluminal angioplasty in aortic coarctation. The short- and median-term results].

    PubMed

    Ledesma Velasco, M; Acosta Valdes, J L; Munayer Calderón, J; Salgado Escobar, J L; Arias Monroy, L; Soberanis Torruco, C N

    1991-01-01

    Percutaneous transluminal angioplasty (PTA) was performed in 34 patients with aortic coarctation (Ao Co). One of them with coarctation after surgical correction, the rest were native Ao Co. We used one balloon in 28 patients and two balloons simultaneously in 6. They were separated in three groups according to the degree of aortic arc hypoplasia. Group I (mild to moderate hypoplasia N = 9) the gradient dropped 39% with angiographic improvement of 48% during the follow-up (m = 13.1 months). Three cases with restenosis, 2 were satisfactory dilated and one was sent to surgery. In Group II (severe hypoplasia N = 4) the gradient dropped 31% with angiographic improvement of 30% (follow-up 16.3 months). Two cases with recoarctation were sent to surgery. In Group III (without hypoplasia N = 21) we obtained dropped of gradient of 71% with angiographic improvement of 60% (follow-up 18.5 months). Two cases were redilated successfully. The complications were: cerebral hemorrhage with death due to hypertensive crisis, (1) cerebral embolism, (1) thrombosis in the puncture site 1 and small aneurysm in dilated zone. (1) We think PTA is a good choice to conventional surgery with low rate of morbidity-mortality. The results depend basically on the anatomic type of coarctation and degree of aortic arch hypoplasia. PMID:1828657

  5. Clinical, angiographic, hemodynamic, perfusional and functional changes after one-vessel left anterior descending coronary angioplasty

    SciTech Connect

    Okada, R.D.; Lim, Y.L.; Boucher, C.A.; Pohost, G.M.; Chesler, D.A.; Block, P.C.

    1985-02-01

    Percutaneous transluminal coronary angioplasty (PTCA) was successfully performed in 20 patients with 1-vessel left anterior descending (LAD) coronary artery disease. Exercise capacity in terms of peak workload, heart rate and systolic blood pressure all increased significantly 1 week after PTCA. All patients had some decrease in stenosis size and gradient. All patients except 1 had an improvement in functional class. Eight of 12 patients with abnormal exercise electrocardiograms before PTCA had normal electrocardiograms after the procedure. Exercise thallium-201 (TI-201) myocardial perfusion images obtained in all 20 patients before and 1 week after PTCA were analyzed using a new computer method designed to quantitate regional myocardial TI-201 distribution, redistribution and clearance rate. Significant improvement in TI-201 activity was present in the anterior and septal segments of the left ventricle 1 week after PTCA. This increase in TI-201 uptake was associated with a significant reduction in the amount of TI-201 redistribution between initial and delayed postexercise images in the same regions. TI-201 clearance rate in the segments supplied by the dilated vessel also improved significantly. Abnormal TI-201 lung uptake was seen in 17 patients before and in 4 patients after PTCA. Exercise ejection fraction response and septal wall motion also improved after PTCA of the LAD stenosis in all 17 patients who had exercise radionuclide ventriculography.

  6. Radiation exposure to patients and operators during diagnostic catheterization and coronary angioplasty.

    PubMed

    Zorzetto, M; Bernardi, G; Morocutti, G; Fontanelli, A

    1997-04-01

    A detailed monitoring, on the basis of single procedures, was undertaken to assess the patient exposure and the occupational doses received by the operators (cardiologist, technician, and nurse) during diagnostic coronary angiography (CAG) and percutaneous transluminal coronary angioplasty (PTCA). The occupational dose to the staff was measured at the collar level using thermoluminescent dosimeters (TLD) to examine the neck and head exposure. Patient exposure was assessed by the dose-area product (DAP in Gy/cm2) and by the skin dose (mGy) at the level of thyroid. The mean neck dose per procedure for cardiologist was about 0.05 mGy, a reasonable level to comply with the International Commission on Radiological Protection (ICRP) eye lens recommended limit. No significant differences were detected between CAG (39 procedures) and PTCA (19 procedures). Relatively high radiation doses are given to the lung of the patient with a significant ICRP lifetime risk of about 10(-3). The patients' mean DAP was 55.9 Gy/cm2 for CAG (79 procedures) and 91.8 Gy/cm2 for PTCA (31 procedures) (P < 0.01). About 70% in CAG and 48% in PTCA of the total dose resulted from the cine examination; in PTCA the total mean DAP was about 60% higher than in CAG procedures. PMID:9096931

  7. Preferential light absorption in atheromas in vitro. Implications for laser angioplasty.

    PubMed Central

    Prince, M R; Deutsch, T F; Mathews-Roth, M M; Margolis, R; Parrish, J A; Oseroff, A R

    1986-01-01

    Laser angioplasty, the in situ ablation of arterial obstructions with laser radiation, has been demonstrated in animal models and early clinical trials. A problem with this technique, however, is the possibility of thermal damage to adjacent or underlying normal tissues that also absorb the radiation. Using a spectrophotometer with an integrating sphere and a specially constructed tunable-dye laser-based spectrophotometer, we evaluated the transmittance and remittance of human cadaveric atheromas and adjacent normal aorta from 250 to 1,300 nm to identify wavebands where there is preferential light absorption by atheromas. Data were analyzed by both the Kubelka-Munk formalism and a Beer's law model. Both methods indicate that atheromas absorb more than normal aorta between 420 and 530 nm. At 470 nm the average Kubelka-Munk absorption coefficient of atheromas from 10 cadavers was 54 +/- 9 cm-1 compared with 26 +/- 6 cm-1 for normal aortic specimens from seven cadavers. Yellow chromophores responsible for the atheroma absorbance were extractable with xylenes. Thin-layer chromatography and absorption spectra identified the extracted chromophores as predominantly consisting of a mix of carotenoids, which are known constituents of atheromatous lesions. Preferential absorption of blue light by carotenoids in atheromas may permit selective ablation of atheromatous obstructions with appropriate pulses of laser radiation. PMID:3722380

  8. A model for optical and thermal analysis of laser balloon angioplasty.

    PubMed

    Cheong, W F; Welch, A J

    1989-12-01

    Laser balloon angioplasty is modeled using an infinitely long cylinder possessing axisymmetry. The balloon surface is assumed to be uniformly irradiated by diffuse light at 1060 nm delivered from within the inner balloon core. The diffusion approximation to the radiative transport equation is solved for a single layer of homogeneous medium enclosing the transparent fluid-filled balloon. The computed light fluence rate (W.cm-2) just beneath the tissue surface is 4.7 times the primary irradiance, owing to scattering and secondary irradiance from the "integrating cylinder" effect of backscattered light into the inner core. The transient temperature response of the heated tissue is then calculated using an implicit finite difference solution of the heat conduction equation for concentric layers of varying thermal properties. Finally, the extent of damage is analyzed using the Arrhenius rate process model. Changes in optical and thermal properties with temperature and thermal phase transitions have been omitted in all our analyses. Irradiances which decrease with time can produce a "temperature plateau" for a longer time period than a constant irradiance of equal total energy output. This may be clinically important. Flexible boundary conditions at the balloon interface permit simulation of a "hot contact surface," such as a black balloon absorbing all incident laser power. In this situation, the computed surface damage is consistently higher than that obtained by LBA of equivalent energy output. PMID:2532617

  9. Relation of Depression, Anxiety, and Quality of Life with Outcome after Percutaneous Transluminal Coronary Angioplasty

    PubMed Central

    Chaudhury, Suprakash; Srivastava, Kalpana

    2013-01-01

    Background. Despite, increasing number of percutaneous transluminal coronary angioplasty (PTCA) being performed, there is a paucity of Indian studies on the psychological effects of PTCA. Aim. To study the relation of anxiety, depression, and health related quality of life with outcome after PTCA. Methods. A total of 35 patients undergoing PTCA were included in the present project with their informed consent. All patients filled a specially designed proforma, the Hospital Anxiety and Depression Scale, Coronary Scale, Seattle Angina Questionnaire, and a health related quality of life measure (EQ 5D) one day before undergoing PTCA. Three days after PTCA patients were reassessed with the Hospital anxiety & depression scale, Seattle angina questionnaire and the EQ 5D. Results. Analysis showed that 46% had significant anxiety and 32.1% had significant depression before PTCA. Following successful PTCA, none of the patients had significant anxiety, and only 2 (3.6%) had significant depression. On the Seattle Angina Questionnaire, physical limitation reduced from 67.9 to 48. Disease perception improved from 21.2 to 37.1. On the EQ5D, the health status improved from 42.7 before PTCA to 78.7 after PTCA. Conclusion. Successful PTCA resulted in significant reduction in anxiety, depression, and physical limitation and improvement in disease perception and health status. PMID:24319368

  10. Intravascular ultrasound imaging of peripheral arteries as an adjunct to balloon angioplasty and atherectomy.

    PubMed

    Korogi, Y; Hirai, T; Takahashi, M

    1996-01-01

    This article reviews many of the applications of intravascular ultrasound (US) imaging for peripheral arterial diseases. In vitro studies demonstrate an excellent correlation between ultrasound measurements of lumen and plaque cross-sectional area compared with histologic sections. In vivo clinical studies reveal the enhanced diagnostic capabilities of this technology compared with angiography. Intravascular US imaging can provide valuable information on the degree, eccentricity, and histologic type of stenosis before intervention, and on the morphological changes in the arterial wall and the extent of excision after intervention. Intravascular US may also serve as a superior index for gauging the diameter of balloon, stent, laser probe, and/or atherectomy catheter appropriate for a proposed intervention. Significant new insights into the mechanisms of balloon angioplasty and atherectomy have been established by intravascular US findings. Intravascular US imaging has been shown to be a more accurate method than angiography for determining the cross-sectional area of the arterial lumen, and for assessing severity of stenosis. Quantitative assessment of the luminal cross-sectional area after the balloon dilatation should be more accurate than angiography as intimal tears or dissections produced by the dilatation may not be accurately evaluated with angiography. At the present time, intravascular US is still a controversial imaging technique. Outcome studies are currently being organized to assess the clinical value and cost effectiveness of intravascular ultrasound in the context of these interventional procedures. PMID:8653738