Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    One-Stage Intrathoracic Repair of Extended Aortic Aneurysms (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cardiac surgery 9 (1994), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Aneurysms of the entire thoracic aorta are usually approached in two to three stages. From 1990 to 1994, we performed one-stage aortic replacement from the root to the diaphragm in 16 patients (8 men and 8 women with a mean age of 55.7 years, range 49 to 73). There were 11 type A dissections, 7 of which were acute. Six patients underwent aortic valve reconstruction; seven had aortic root replacement by Bentall or Cabrol techniques. In two cases, the Innominate artery had to be replaced by a vascular graft separately in addition to reimplantation of the supraaortic branches as an island flap into the arch prosthesis. In eight cases, a median sternotomy was used; eight had a bilateral transverse thoracotomy. The procedure was performed under deep hypothermlc circulatory arrest in all cases (mean duration 50.5 mln, range 38 to 62 min). Two patients, both operated upon for an acute dissection, expired perioperatively: one due to a bronchopneumonia, and one because of a thrombosed Cabrol graft to the right coronary artery. No patient developed bleeding or neurological complications. At a mean follow-up of 26.9 months (1 to 50 months), all patients discharged from the hospital were still alive. Four patients underwent subsequent thoracoabdominal aortic replacement. This experience suggests that complete thoracic aortic replacement can be performed in a single session with an operative risk comparable to that of the conventional two-stage approach. The bilateral transverse thoracotomy affords excellent exposure. The lack of spinal cord ischemia may be the result of spinal cord protection with hypothermic circulatory arrest and use of the open-clamp technique. (J Card Surg 1994;9:604–613)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8191.1994.tb00893.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Clinical Experience with Expanded Polytetrafluoroethylene Gore-Tex® Surgical Membrane for Pericardial Closure: A Study of 110 Cases (1988)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cardiac surgery 3 (1988), S. 0 
    Details
    ISSN: 1540-8191
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Complete closure of the pericardium after cardiac operations has the advantage of avoiding injury of the heart and great vessels during reoperation. Between 1985 and 1987, the pericardium was closed with Gore-Tex® Surgical Membrane (SM) in a selected series of 110 patients 1 month to 76 years of age. Fifty-three patients had congenital heart lesions and 57 patients had acquired heart disease. Overall hospital mortality was 3/110 cases. In no instance was there a relationship between occurrence of death and pericardial closure with SM. There was one episode of cardiac tamponade on the seventh postoperative day. One patient developed fever and leukocytosis due to a mediastinal hematoma. During a mean follow-up of 15 months,3–27 four patients had to be reoperated upon three, four, eight weeks, and eight months after primary operation. The anterior wall of the heart had no adhesion with the SM and the other parts of pericardium could be dissected easily. Scanning electron microscopic examination of the explanted SM patches showed neither cellular ingrowth nor immunocompetent cellular elements.The Gore-Tex® Surgical Membrane has the advantages of easy availability and lack of reaction between its surface and the epicardium and pericardium. We believe its routine use should be encouraged in patients with high probability of reoperation after repair of complex cardiac anomalies, implantation of bioprostheses, coronary revascularization for one- or two-vessel disease, and repair of degenerative disease of the ascending aorta.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8191.1988.tb00239.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    PTCA: Is Surgical Back-up Necessary? The View of a Surgeon and a Lawyer (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of interventional cardiology 7 (1994), S. 0 
    Details
    ISSN: 1540-8183
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8183.1994.tb00882.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Influence of Polarity Reversal on de-fibrillation Success with Biphasic Shocks and a Transvenous/Subcutaneous Defibrillator System in a Porcine Animal Model (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 21 (1998), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Clinical studies show that polarity reversal affects de-fibrillation success in transvenous monophasic defibrillators. Current devices use biphasic shocks for de-fibrillation. We investigated in a porcine animal model whether polarity reversal influences de-fibrillation success with biphasic shocks. In nine anesthetized, ventilated pigs, the de-fibrillation efficacy of biphasic shocks (14.3 ms and 10.8 ms pulse duration) with “initial polarity” (IP, distal electrode = cathode) and “reversed polarity” (RP, distal electrode = anode) delivered via a transvenous/subcutaneous lead system was compared. Voltage and current of each defibrillating pulse were recorded on an oscilloscope and impedance calculated as voltage divided by current. Cumulative de-fibrillation success was significantly higher for RP than for IP for both pulse durations (55% vs 44%, P = 0.019) for 14.3 ms (57% vs 45%, P 〈 0.05) and insignificantly higher for 10.8 ms (52% vs 42%, P = n.s.). Impedance was significantly lower with RP at the trailing edge of pulse 1 (IP: 44 ± 8.4 vs RP: 37 ± 9.3 with 14.3 ms, P 〈 0.001 and IP: 44 ± 6.2 vs RP: 41 ± 7.6 Ω with 10.8 ms, P 〈 0.001) and the leading edge of pulse 2 (IP: 37 ± 5 vs RP: 35 ± 4.2 Ω with 14.3 ms, P = 0.05 and IP: 37.5 ± 3.7 vs RP: 36 ± 5 Ω with 10.8 ms, P = 0.02). In conclusion, in this animal model, internal de-fibrillation using the distal coil as anode results in higher de-fibrillation efficacy than using the distal coil as cathode. Calculated impedances show different courses throughout the shock pulses suggesting differences in current flow during the shock.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1998.tb00215.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Optimized Pulse Durations Minimize the Effect of Polarity Reversal on Defibrillation Efficacy with Biphasic Shocks (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 22 (1999), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: There are conflicting results on the effect of polarity change on the defibrillation efficacy of biphasic shocks possibly caused by different shock durations. The goal of the present study was to investigate the influence of polarity reversal on defibrillation efficacy for different biphasic shock durations in a porcine animal model. In eight anesthesized pigs using a transvenous/submuscular lead system DFTs for 4 phase 1 durations were determined: 8.1 ms, 6 ms, 3.8 ms and 1.7 ms. The phase 1/phase 2 ratio was constant at 60%/40%. For cathodal shocks, the defibrillation coil in the right ventricular apex was the cathode during phase 1 and for anodal shocks it was the anode. For both polarities, the strength-duration curve revealed a DFT minimum at 3.8 ms (cathodal shocks: 21.3 ± 6.4 J, P 〈 0.001; anodal shocks: 21.9 ± 8 J, P = 0.05). For anodal shocks and phase 1 durations of 1.7, 3.8, and 6 ms there was no significant difference of the stored energy at the DFT compared to cathodal shocks. In contrast, significantly lower DFTs were observed for anodal shocks with a phase 1 duration of 8.1 ms (28.8 ± 6.4 J compared to 33.1 ± 5.9 J for cathodal shocks, P = 0.006). The effect of lower defibrillation energy requirements with polarity reversal depends on the total biphasic shock duration; for the pulse duration with the lowest DFT, polarity reversal does not increase defibrillation efficacy of biphasic shocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1999.tb00545.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Polarity Reversal Improves Defibrillation Efficacy in Patients Undergoing Transvenous Cardioverter Defibrillator Implantation with Biphasic Sbocks (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 20 (1997), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The purpose of this study was to determine the influence of polarity reversal on DFT in patients undergoing implantation of nonthoracotomy defibrillators with biphasic shocks. Previous studies have shown higher defibrillation efficacy with using the distal electrode as anode in implantation of nonthoracotomy defibrillators and monophasic shocks. However, it is as yet unclear whether biphasic shock defibrillation will also be influenced by polarity reversal. Using a transvenous lead system with a proximal electrode in the superior caval vein and a distal electrode in the RV apex, 27 patients undergoing defibrillator implantation were randomized to DFT testing with “initial” (distal electrode = cathode) or “reversed” polarity (distal electrode = anode). Defibrillation energy was reduced stepwise until defibrillation failure occurred. At this point, polarity was switched and testing continued until the lowest energy requirement was determined for both polarities. With reversed polarity, DFT was 11.1 ± 5.7 J versus 13.3 ± 5.8 J with initial polarity (P = 0.033). This means a 17% reduction of the DFT. In 10 patients, the threshold was lower with reversed, whereas in 3 patients it was lower with initial polarity. In conclusion, changing electrode polarity in transvenous implantable defibrillators with biphasic shocks may significantly influence defibrillation energy requirements. Therefore, polarity reversal should always be attempted before considering patch implantation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1997.tb06174.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Technique and results of human heart transplantation (1969)
    Springer
    Langenbeck's archives of surgery 326 (1969), S. 5-24 
    Details
    ISSN: 1435-2451
    Keywords: Heart-transplantation ; Lung-transplantation ; Cardiac prosthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary As of June 30, 1969, 21 heart transplantations have been performed in 20 patients having end-stage heart disease. The surgical technique for cardiac and cardiopulmonary allotransplantation is standardized and no patient in the present series died for technical reasons. Postoperative catheterization studies showed adequate performance of the allografts with slower but satisfactory adaptation to exercise. Survival after cardiac allotransplantation ranged from 14 h to nearly 9 months. At the present time two patients are still alive, 27 and 226 days after transplantation. Rejection, either acute or chronic, was the primary cause of death in 10 patients: infection stimulated by the immunosuppression, in five. Lack of donors represents another serious problem. An attempt to save a patient with a cardiac xenograft failed. New hope is offered by the first clinical use of an orthotopic cardiac prosthesis to bridge the period between complete failure of a patient's heart and the availability of an allograft. The results demonstrate that cardiac allotransplantation can be an effective palliation for patients with end-stage heart disease, but many immunological problems must be solved before wide clinical application can be approved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01238410
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    124. Mechanische orthotope Substitution des Herzens:In vitro-Untersuchungen kardialer Prothesen (1971)
    Springer
    Langenbeck's archives of surgery 329 (1971), S. 375-383 
    Details
    ISSN: 1435-2451
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einem eigens entwickelten Kreislaufsimulator wurden in den letzten Jahren drei verschiedene Typen pneumatisch betriebener künstlicher Ventrikel auf ihre Leistungsfähigkeit ausgetestet. Mit einem maximalen effektiven Minutenvolumen von 60% des vorberechneten Wertes erwiesen sich der ursprüngliche unidiaphragmale Typ und eine bidiaphragmale Neukonstruktion einer sackförmigen Konstruktion überlegen. Maßgebend für die Effektivität eines künstlichen Ventrikels ist neben der Beschaffenheit der Außenschale und der Form der Trennmembran zwischen pneumatischem und hämodynamischem bzw.hydrodynamischem System des Klappenmechanismus. Daher wurden die hydrodynamischen Eigenschaften verschiedener Klappen im Zusammenhang mit dem bidiaphragmalen Ventrikel untersucht. Um das Schlagvolumen optimal zu halten, muß die InfloWoder Mitralklappe einen möglichst kleinen Gradienten aufweisen, während bei der Outflow- oder Aortenklappe eine möglichst geringgradige Insuffizienz gefordert wird. Von den getesteten Klappen erfüllen in mitraler Position die montierte Fascia lata-Klappe und in aortaler Position die Björk-Shiley-Prothese diese Bedingungen am besten. Mittels sorgfältiger in vitro-Untersuchungen künstlicher Ventrikel gelingt es, gültige Aussagen über deren Leistungsfähigkeit in späteren Tierversuchen zu machen und untaugliche Modelle von vorneherein auszuschließen.
    Notes: Summary During the past years three different types of pneumatically driven artificial ventricles have been studied in a special mock circulatory system. The original unidiaphragmatic type and a bidiaphragmatic new construction yielded a cardiac output of 60% of the precalculated value. Both types were superior to a sacciform ventricle. The efficiency of an artificial ventricle is dependent upon the construction of the external wall and the form of the diaphragms separating the pneumatic and hymodynamic systems. Moreover the valve mechanism plays an important role. Therefore the hydrodynamic characteristics of different valves were studied using the bidiaphragmatic type ventricle. To guarantee an optimal stroke volume a minimal gradient across the inflow or mitral valve is mandatory while the important factor at the outflow or aortic valve is minimal backflow. Of the studied valves the stented fascia lata meets best the requirements in mitral position, while in aortic position the Björk-Shiley tilting disc prosthesis gives the best results. The efficiency of a new artificial ventricle can be tested by careful in vitro studies in a mock circulatory system and it is possible to eliminate a unfit type before expensive animal experiments are started.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01770543
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...