ABSTRACT: Patients receiving implantation of ventricular assist devices (VAD) suffer a high incidence of heparin induced thrombocytopenia (HIT); the occurrence of this condition is associated with increased complications and worse outcomes. We report our experience in the management of patients who were diagnosed with HIT either before (HITpre) or after (HITpost) implantation of VAD with argatroban, a direct thrombin inhibitor.
This retrospective analysis assessed data of VAD patients diagnosed with HIT at Deutsches Herzzentrum Berlin between November 2005 and April 2009. Argatroban dose requirements, anticoagulation efficacy and adverse events (death, thromboembolism, bleeding) were recorded. Procedural success (discharge from the hospital, heart transplantation, or recovery of the failing heart) was also assessed.
Twenty-seven patients were identified (11 HITpre, 16 HITpost). Argatroban was effective in obtaining adequate anticoagulation with a reduced dose regimen (0.02-0.42 mcg/Kg/min starting dose; 0.02-1.5 mcg/Kg/min maintenance dose). We noted 5 thromboembolic complications (18%), 6 cases of major bleeding (22%) and 5 deaths (18%), all cause composite adverse end point occurring in 40% of patients. Procedural success was obtained in 81% of patients (92% HITpre, 69% HITpost). As compared to historical controls of patients treated with lepirudin in the period 2000-2005, results were significantly improved.
Argatroban anticoagulation is feasible in patients with HIT after VAD implantation, without increasing bleeding risk. Its impact in terms of survival should be reviewed also in the light of the technological improvements of assist devices.
Minerva anestesiologica 03/2012; 78(3):330-5. · 2.66 Impact Factor
ABSTRACT: In recent years, ventricular assist devices (VAD) supporting the left (LVAD), the right (RVAD) or both ventricles (BVAD) have rapidly emerged as the standard of care for advanced heart failure patients. Both the numbers and ages of patients in which they are used are rising worldwide, especially when used as a permanent support (bridge to destination, BTD). Due to the continuing lack of donor organs, these devices now represent a viable alternative to bridge patients to transplantation (BTT), with a 1-year survival rate of 86%. BTD, especially in long-term support, might be a valid, and the sole, option for those patients in whom heart transplantation is contraindicated. Patient selection, pre- and intra-operative preparation, as well as the timing of VAD implantation are important factors critical to successful circulatory support. While BTT remains the goal in the majority of patients, the number of permanent VADs (i. e. BTD) is rising significantly. Although explantation of a VAD system as a bridge to recovery (BTR) can be considered in only a small number of patients, it represents a very special part of this therapy modality.
Herz 09/2011; 36(7):622-9. · 0.92 Impact Factor
ABSTRACT: The feasibility of bivalirudin for anticoagulation during cardiac surgery has been confirmed in four multicenter clinical trials. Here, we report our single-center experience with bivalirudin anticoagulation in "on-pump" and "off-pump" cardiac surgery in a large number of patients with and without heparin antibodies. Data of patients who underwent cardiac surgery with bivalirudin anticoagulation between 06/2003 and 12/2007 at our institution were reviewed. Assessment included procedural success, blood loss, transfusion requirements, re-exploration rates and drug-related complications during the procedures. There were 141 patients treated with bivalirudin, of whom 40 had heparin antibodies. In 26 patients, "off-pump" coronary artery bypass grafting was performed and the remaining 115 patients had surgery with cardiopulmonary bypass (CPB). The procedural success rate after 7 days and after 30 days was 99.4%. The mean blood loss after "off-pump" surgery was 833 +/- 310 ml, with a transfusion rate of 30%. The mean blood loss after "on-pump" surgery was 750 +/- 494 ml, with a transfusion rate of 56%. Two patients needed re-exploration due to persistent hemorrhage. Overall transfusion rates were increased in patients with heparin antibodies. The current investigation demonstrates that, in experienced hands, bivalirudin anticoagulation can be performed with excellent procedural success and low complication rates during "on-pump" and "off-pump" cardiac surgery. Recent problems associated with the production of heparin have emphasized the urgent need for an alternative for use beyond the limited indication of heparin-induced thrombocytopenia.
Perfusion 02/2009; 24(1):7-11. · 0.92 Impact Factor
ABSTRACT: The aim of this study was to evaluate the safety and efficacy of a new endovascular thoracic stent-graft, which was designed to overcome the restrictions of previously used stent-grafts.
Between May 2004 and March 2008 a prospective evaluation was conducted in 126 consecutive patients (71% men; age 64 [19-86] years). A total of 138 implantations were performed. E-vita stent-grafts were implanted for type-B dissection (N.=56), degenerative aneurysm (N.=25), penetrating aortic ulcer (N.=17), blunt traumatic lesions (N.=10), mobile atheroma (N.=1), suture aneurysms (N.=7) and revisionary surgery following previous endograft implantation (N.=22). All patients eligible for stent-grafting were treated with this system regardless of their clinical status and aortic pathology. The percentage of emergency procedures was 52% (N.=72). Per implantation a mean of 1.3 segments was implanted with an effective total covered length of the aorta of mean 204 mm, median 230 mm (0-450 mm). In 32 of 39 cases with more than one segment, the entire descending aorta was included in the procedure.
The 30-day mortality rate was 12.3% (17 patients). All deaths but one were in the group of emergency surgery patients. This results in mortality of 1.5% in the elective and 22% in the emergency procedures. Reversible procedure-induced spinal cord ischemia was observed in 2 cases. Stroke occurred in 2.8% (4 patients). Primary technical success was rated at 77 % (106 procedures) and secondary success at 89 % (124 procedures).
All forms of thoracic aortic disease can be treated with this new stent-graft. It has proved particularly valuable in cases of difficult conditions in the aortic arch and extended aneurysms. In particular, it is possible to cover the entire thoracic aorta with two or three stent-graft segments, thus considerably reducing the number of connections.
The Journal of cardiovascular surgery 09/2008; 49(4):417-28. · 1.56 Impact Factor
ABSTRACT: HintergrundEndograftimplantationen im oder am Aortenbogen stellen besondere Herausforderungen an die Implantationstechnik und an die
mechanischen Eigenschaften von Stentgrafts und ihren Einführungssystemen, bedingt durch die Notwendigkeit, die Prothesen punktgenau
abzusetzen und durch die mit der Biegung im Aortenbogen zunehmende Reibungswiderstände innerhalb der Einführungssysteme. Die
Endograftsysteme der 1. Generation (Talent®, Zenith TX 1®, TAG®) zeigten in dieser Lokalisation technisch bedingte Limitationen.
Neue ProthesenBei den seit 2004 und 2005 verfügbaren neuen Stentgrafts (E-vita®, Zenith TX 2®, Valiant®, Relay®) sind diese Limitationen weitgehend überwunden. Durch technische Verbesserungen von Stentgrafts und Einführungssystemen ist
es nun möglich, auch lange Segmente bis zu 230 mm präzise im Aortenbogen freizusetzen. Durch Verzicht auf einen Längsdraht
(E-vita®, Zenith TX 2®, Valiant®) bzw. Modifikation des Längsdrahtes (Relay®) sind diese neuen Prothesen flexibler als die von uns zuvor vornehmlich verwendete Talent®. Die neuen Prothesen unterscheiden sich in wesentlichen technischen Details, vor allem hinsichtlich der verwendeten Metallkomponenten
(Nitinol vs. Edelstahl) und der proximalen Fixierungsmechanismen (freie Federn vs. Haken oder glattem Abschluss). Diese Unterschiede
sind bei differenzierter Indikationsstellung zu berücksichtigen.
Eigene ErfahrungenWir haben im Aortenbogen bis 2004 fast ausschließlich Talent® (73 Patienten) und seitdem E-vita® (37 Patienten) implantiert. Die Erfahrungen mit der E-vita® sind sehr positiv. Dieses Implantat erschließt komplexe Aortenerkrankungen mit Beteiligung des Bogens der endovaskulären
Therapie. Mit Sonderanfertigungen, die innerhalb kurzer Zeit produziert und geliefert werden, ist auch die Versorgung schwieriger
anatomischer Verhältnisse möglich. Die Erfahrungen mit den anderen neuen Systemen beschränken sich noch auf Einzelfälle.
Weitere EntwicklungenMit einem neu entwickelten Hybrid-Endograft aus endovaskulärer und konventioneller Aortenprothese (E-vita open®) können komplexe Aortenerkrankungen mit Beteiligung der Aorta ascendens, des Aortenbogens und der Aorta descendens einzeitig
im Kreislaufstillstand und tiefer Hypothermie operiert werden. Endoprothesen mit Seitenarmen oder Fenestrationen könnten das
Spektrum der endovaskulären Behandlung weiter bereichern. Entwicklungsarbeiten hierzu sind im Gange.
BackgroundEndograft implantations in or near the aortic arch represent a special challenge in terms of implantation technique and the
mechanical properties of the stent grafts and their delivery systems. This is because the endografts have to be delivered
precisely at the designated landing spot and because the frictional resistance of the delivery systems increases dramatically
when they are bent in the aortic arch. The endografts of the first generation (Talent®, Zenith TX 1®, TAG®) had technical limitations in this anatomical location.
New stent graftsThe new stent grafts available since 2004 and 2005 (E-vita®, Zenith TX 2®, Valiant®, Relay®) have mostly overcome these limitations. Due to technical improvements of the stent grafts and delivery systems it is now
possible to deploy even long segments up to 230 mm precisely in the aortic arch. By avoiding a longitudinal bar (E-vita®, Zenith TX 2®, Valiant®) or modification of this bar (Relay®) these new endografts are far more flexible than the Talent® graft, which we predominantly used before. The new stent grafts are significantly different in technical details, basically
in the metal components (nitinol vs. stainless steel) and the proximal fixation mechanisms (bare springs vs. hooks and barbs
or simple closed web). These differences have to be considered in individual indications.
Our experienceIn the aortic arch we implanted almost exclusively the Talent® stent graft up to 2004 (73 patients) and since then the E-vita® (37 patients). Our experience with E-vita® is very positive. This graft opens up possibilities of endovascular treatment of complex pathology of the aorta, including
the aortic arch. With the custom made devices produced and delivered within a short period of time even more complex aortic
diseases can be treated. We have used the other new devices in a only small number of cases so far.
Advanced developmentsWith a newly developed hybrid endograft combining stent graft and conventional dacron prosthesis (E-vita open®), aortic diseases involving the ascending aorta, the aortic arch and the descending aorta can be repaired in a one-stage
procedure in circulatory arrest and deep hypothermia. Branched or fenestrated endografts for the aortic arch may further expand
the spectrum of endovascular surgery. This is the task of ongoing research and development.
Zeitschrift für Herz- Thorax- und Gefäßchirurgie 01/2006; 20(1):1-8.
ABSTRACT: In uremic patients coronary surgery and the entire perioperative management is demanding.
We analyzed retrospectively data from all patients requiring chronic hemodialysis who under went coronary artery bypass grafting (CABG) between January 1 2001 and December 31 2004 at the Deutsches Herzzentrum Berlin and compared them to those of a randomized nonuremic control group (n = 68), which consisted of patients who underwent CABG during the same period.
During the study period 6315 patients underwent coronary artery bypass grafting at the Deutsches Herzzentrum Berlin. Among these patients, we identified 71 chronic dialysis patients (1.12%). Among dialysis patients, we recorded a perioperative mortality of 5.6%. One-year survival rate was 87.7% among uremic patients and 91.0% in the control group; the corresponding 4-year survival rates were 56.7 and 88.0%, respectively. The incidence of peripheral artery disease was significantly higher in the dialysis group. Uremic patients showed significantly lower hemoglobin serum levels at the time of admission compared to the control group (11.4 +/- 1.62 vs. 13.3 +/- 1.81 mg/dl). These patients received significantly higher numbers of blood transfusions (6.7 +/- 5.6 vs. 2.75 +/- 3.8), and platelet transfusions.
Our preliminary study indicates that coronary surgery can be performed with acceptable mid-term results when the specific requirements of this patient group are taken into account.
Kidney and Blood Pressure Research 02/2005; 28(5-6):270-4. · 1.46 Impact Factor
ABSTRACT: Die transmyokardiale Laserrevaskularisation (TMLR) wird bei Patienten mit schwerer, diffuser, sklerosierender 3-Gefäß-KHK
angewendet, die unter maximaler medikamentöser Therapie stehen und keine Kandidaten für eine Katheterintervention (PTCA mit
oder ohne Stentimplantation), aortokoronare Bypassoperation oder Herztransplantation sind. Jedoch profitieren nur 65–70% der
Patienten von der TMLR. Aus diesem Grund untersuchten wir an 20 präoperativ bekannten Faktoren den Einfluss auf den Benefit
nach TMLR. Wir führten eine logistische Regressionsanalyse bei 134 Patienten durch, die an unserer Institution von November
1994 bis April 2001 einer isolierten TMLR unterzogen wurden.
Responder und Non-Responder unterschieden sich signifikant voneinander in Bezug auf die Inzidenz eines Diabetes mellitus.
Patienten mit Diabetes mellitus hatten nur eine Chance von 43% von der TMLR zu profitieren im Vergleich zu Patienten ohne
Diabetes mellitus (odds ratio=0,43 [0,20–0,92]). Weiterhin bestand bei Patienten mit einem Body mass Index >25 ein ca. dreifach
erhöhtes Risiko im ersten postoperativen Jahr nach TMLR zu versterben im Vergleich zu Patienten mit einem Body mass Index
von 25 oder größer (odds ratio=2,97 [1,05–8,40]). Bei der 1-Jahres-Überlebenswahrscheinlichkeit hatte die Inzidenz eines Diabetes
mellitus einen tendenziellen, aber soeben nicht signifikanten Einfluss (p=0,058).
Aufgrund dieser Daten sind wir zurückhaltender geworden, Patienten mit Diabetes mellitus einer TMLR zu unterziehen.
Transmyocardial laser revascularization (TMR) has been used during the last years for patients with diffuse coronary artery
disease. These patients take antianginal drugs and are not candidates for percutaneous transluminal coronary angioplasty,
bypass grafting or heart transplantation. But only 65–70% of the patients profit from TMR. We performed an univariate logistic
regressions analysis of 20 factors on the benefits and outcomes after TMR. We analysed 134 patients who were operated by isolated
TMR at our institution between November 1994 and April 2001. Responder and non-responder differed significantly to the
incidence of diabetes mellitus. The chance of profiting from TMR was for patients with diabetes mellitus only 43% compared
to patients without diabetes mellitus (odds ratio=0.43 [0.20–0.92]). Patients with a preoperative body mass index less than
25 had a threefold increase in the chance of death during the first year after TMR compared to patients with a body mass index
of 25 or more (odds ratio=2.97 [1.05–8.40]). Also the incidence of diabetes mellitus was slightly but not significantly different
between 1-years survivors and non-survivors (p=0.058). Now we recommend caution in selecting TMR to diabetic patients.
Zeitschrift für Herz- Thorax- und Gefäßchirurgie 01/2003; 17(1):17-23.
ABSTRACT: Left ventricular function is the most important predictor of survival in patients with coronary artery disease. It is also an important indicator for hospital mortality after operation for end-stage coronary artery disease. In our study we investigated, how preoperative ventricular dysfunction influences long term survival after coronary bypass surgery.
Between 4/1986 and 12/2000, 1751 patients (1440 men/311 women) with left ventricular ejection fraction (LVEF) 10-30% underwent coronary bypass grafting (CABG) at the Deutsches Herzzentrum Berlin. The age of the patients was calculated to an average of 59,2 years. The prime criterion for CABG was ischemia ("hibernating myocardium") diagnosed by myocardial scintigraphy, echocardiography and in some cases with magnetic resonance imaging and positron emission tomography.
Operative mortality for the group was 7,1%. The actuarial survival rate was 87,6% after 2 years, 76,0% after 5, and 53,3% after 9. 455 had LVEF 10-20%, in these actuarial survival was 79,8% after 2 years, 63,0% after 5 and 45,7% after 9 years.
We conclude that CABG can be used successfully to improve life expectancy of patients with end-stage coronary artery disease. CABG leads to acceptable prognosis for these high-risk patients when the myocardium is preoperatively identified as being viable.
DMW - Deutsche Medizinische Wochenschrift 12/2002; 127(47):2503-7. · 0.53 Impact Factor
ABSTRACT: Four risk-stratification scores (RSSs - Euro, French, CCS/Higgins, Parsonnet) were tested as predictors of mortality in coronary artery bypass grafting (CABG) surgery.
From March to April 2000, the perioperative courses of 245 consecutive CABG patients were compared to the predictions according to the RSSs. Sensitivity and specificity were determined with receiver operating characteristics (ROC) curves.
CCS/Higgins uses the most easily acquired patient data, and rates emergency conditions as high-risk. Euro focuses on advanced age and septal rupture. French uses the smallest number of patient parameters and rates rare critical situations as high-risk. Parsonnet is partially based on the physician's subjective assessment of a "catastrophic state," making the scoring arbitrary. All RSSs gave similar (not significant) areas under the ROC curves regarding mortality (Euro 0.826 +/- 0.080, French 0.783 +/- 0.094, CCS/Higgins 0.820 +/- 0.060, Parsonnet 0.831 +/- 0.042). Predicted risk levels for the 11 patients who died differed between the RSSs--Higgins placed these patients in 3 of 5 risk levels with ascending distribution. The other RSSs placed these patients in the highest risk level except for one and two patients, respectively, who were placed in the lowest Euro and French risk level. Euro and Parsonnet placed about half of all patients with non-lethal outcome in the highest risk level.
All RSSs satisfactorily estimated the group risk for mortality. No RSS expressed sufficient validity to predict individuals with lethal outcome. In clinical use, CCS/Higgins proved the most practicable.
The Thoracic and Cardiovascular Surgeon 09/2002; 50(4):237-46. · 0.88 Impact Factor
Journal of Thoracic and Cardiovascular Surgery 01/2002; 122(6):1254-5. · 3.41 Impact Factor
ABSTRACT: We report on a patient with coronary artery 3-vessel disease who presented 30 years after a unilateral Vineberg operation with a patent graft. The patient successfully underwent coronary artery bypass grafting. The theoretical basis, operative variations and the results of this historical indirect revascularization procedure are briefly discussed.
Zeitschrift für Kardiologie 11/2001; 90(10):774-7. · 0.97 Impact Factor
ABSTRACT: Transmyocardial laser revascularization (TMR) is the only surgical treatment for patients with severe diffuse coronary artery disease, who are not candidates for bypass grafting or percutaneous angioplasty. However, vaporization of tissue during the creation of channels leads to a certain loss of viable myocardium during every TMR procedure.
We analyzed serum levels of creatine kinase and creatine kinase MB subtype in 163 patients after sole TMR with a CO2 laser (wave length 10.6 microm, 800-watt power). The control group consisted of 35 consecutive CABG patients and 30 consecutive redo-CABG patients. Additionally, in the TMR group we measured echocardiographically the left ventricular ejection fraction before and after TMR. We recorded the total amount of laser energy applied, average and maximum energy per channel, and the number of created channels, in order to calculate the correlation between these parameters and postoperative enzyme levels or changes in the LVEF.
After TMR, we measured higher creatine kinase levels compared to those in CABG patients (607.8+/-558.4 U/L vs. 285.0+/-292.3 U/L, p < 0.01). The relative proportion of CK-MB of total CK, however, was significantly lower after TMR, compared to that of the control group (4.5+/-3.0% vs. 10.1+/-6.4%, p < 0.01). Patients with a pronounced postoperative increase in CK-MB levels or a higher percentage of CK-MB of total CK also after TMR operations show a decline in left ventricular contractility. In the laser group, the maximum enzyme levels were detected significantly later than in the control group (25.0+/-19.4 h postoperatively vs. 8.7+/-9.1 h, p < 0.01). There was no significant correlation between the technical laser parameters or the number of created channels and the percentage of CK-MB of total CK or changes in left ventricular ejection fraction.
CO2 laser TMR does not result in significant injury to the myocardium. Cardiac enzymes play an important role in the detection of perioperative myocardial infarction in TMR patients.
Journal of Clinical Laser Medicine & Surgery 10/2001; 19(5):251-9.
ABSTRACT: Risk scores (RS) in heart surgery assess mortality and morbidity and mirror the degree of severity of disease of the patients when presented for surgery. We examined the use and dissemination of RS in Germany.
Our survey included 79 German heart surgery institutes in Fall 1999 and Winter 2000.
Four institutes did not respond. Out of 75 (ad 100 %) responders 56 (75 %) institutes did not use RS, 17 (22 %) institutes used one RS method and 2 (3 %) institutes used two RS methods. The most frequently applied RS methods were the Cleveland Clinic Score and the Euro Score (n = 7, each) followed by institution-specific, internally developed RS methods (n = 5), Parsonnet's RS (n = 1) and the RS from the STS database (n = 1). Fourteen institutes used RS for internal quality control. Of these, 2 institutes publish their RS data for external quality control. The patient-related individual procedure risk was used in 6 institutes.
A quarter of the German heart surgery institutes use one or more RS methods. The most commonly used were the Cleveland Clinic Score and the Euro Score, followed by internally developed RS methods. RS methods were most frequently used for internal quality control. The degree of the severity of disease of the patients who presented for surgery could only be compared between a small number of institutes using the same RS.
The Thoracic and Cardiovascular Surgeon 09/2001; 49(4):254-5. · 0.88 Impact Factor
ABSTRACT: In ischemic cardiomyopathy (left ventricular ejection fraction [LVEF] < or = 30%), myocardial revascularization by coronary artery surgery has better results than heart transplantation, provided there is sufficient ischemic but viable myocardium. The mode of action of transmyocardial laser revascularization (TMR) is still being debated, but if the procedure induces improved myocardial perfusion it could be a "bridge," or alternative, to heart transplantation.
We retrospectively analyzed 194 patients, who underwent TMR between July 1997 and October 1999. Patients with TMR as an adjunct to coronary artery surgery (n = 30) and those who did not provide written consent to the procedure (n = 8) were excluded; 126 patients had normal or moderately reduced left ventricular function, and 30 patients with ischemic cardiomyopathy (LVEF < or = 30%) were included.
After 12 months, the Canadian Cardiovascular Society (CCS) score dropped significantly from 3.6 (3 to 4) to 2.4 (1 to 4) and maximum work load increased significantly from 58 W (25 to 100 W) to 73 W (25 to 120 W). However, thallium score and LVEF did not improve significantly (27% [15% to 30%] to 32% [15% to 45%]). Prior to the TMR procedure, all 30 patients had a "low risk" or "medium risk" of death according to the Aaronson classification. The 30-day, 1-year, and 2-year survival rates were 83%, 50%, and 47%, respectively.
We conclude that TMR in ischemic cardiomyopathy (LVEF < or = 30%) has a perioperative risk comparable to that for heart transplantation, but there is no improvement of myocardial performance or life expectancy. Therefore, TMR cannot be regarded as a "bridge," or alternative, to transplantation. However, in individual cases with contraindications for transplantation the anti-anginal effect may justify use of the procedure.
The Journal of Heart and Lung Transplantation 06/2001; 20(6):687-91. · 4.33 Impact Factor
ABSTRACT: Today there is no doubt that angina in patients with diffuse end-stage coronary artery disease can be treated effectively by transmyocardial laser revascularization (TMLR). But until now, the underlying mechanism of TMLR is a matter of debate. The aim of this study was to investigate the immediate changes in functional and metabolic parameters after the creation of TMLR channels. In 12 pigs the local myocardial function (pressure-wall thickness-loops), tissue oxygen partial pressure (PO(2)), and the left ventricular intramyocardial wall pressure (IMP) was investigated simultaneously. The left ventricle was divided into 3 areas. Ischemia was induced in regions 1 and 2 by interrupting the coronary blood flow via the left anterior descending artery for 30 seconds. Region 3 served as non-ischemic control region. Thirty minutes after creation of 15-20 TMR channels in region 1, we repeated the coronary occlusion in regions 1 and 2 followed by measurement of all parameters in the 3 regions. The TMLR-treated region 1 showed a better contractility, a higher tissue PO2 and a higher intramyocardial wall pressure during the post-TMLR coronary occlusion in 8 out of 12 pigs when compared with the pre-TMLR occlusion (p<0.05), whereas the untreated region 2 continued to show severe disturbances in myocardial contractility combined with a lower tissue PO(2) and lower IMP during ischemia. Our results suggest that a blood flow via the laser channels immediately after TMLR is principally possible. However, because the channels seem to occlude in the early postoperative phase, the long-term effects of TMLR are likely to be a result of other mechanisms.
Annals of thoracic and cardiovascular surgery: official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia 12/2000; 6(6):383-8. · 0.69 Impact Factor
Circulation 11/2000; 102(14):1724-5. · 14.74 Impact Factor
ABSTRACT: Die Indikationen zur Magnetresonanztomographie (MRT) bei Trägern künstlicher Herzklappen sind kritisch. Eine generelle Kontraindikation
gegen die MRT ist zweifelhaft. Einige diagnostische Fragestellungen wie Prozesse in der hinteren Schädelgrube, Spinalabszesse
und bei Beschwerden im Inneren des Knies lassen sich durch die MRT besser untersuchen als mit anderen radiologischen Verfahren.
Die MRT kann Träger künstlicher Herzklappen auf dreierlei Weise direkt beeinträchtigen: 1) Bewegung und Dislozierung der Klappenprothese,
2) Erwärmung und 3) Induktion von Arrhythmien durch elektrische Ströme, und indirekt durch eine Verzerrung des MRT-Bildes
mit der Gefahr einer diagnostischen Fehlinterpretation. Die gegenwärtige Literatur über Sicherheitsaspekte der MRT bei Trägern
künstlicher Herzklappen erscheint nicht ausreichend. Deshalb wurde 1998 eine Umfrage unter fünfundzwanzig Herstellern künstlicher
Herzklappen durchgeführt bezüglich der Kompatibilität, Sicherheit, oder der Kontraindikation der MRT ihrer jeweiligen Klappenprothese.
Die in Europa führenden Klappen-Hersteller bescheinigten eine MRT-Sicherheit. Einige Firmen stützten ihre Aussagen auf nicht
einzusehende Untersuchungen, oder übertrugen die Verantwortung auf den Arzt, der die MRT durchführt. Andere Firmen gaben keine
MRT-Sicherheitsgarantie oder antworteten nicht. Zwei Klappenhersteller warnten explizit vor der MRT bei bestimmten Prothesentypen.
Aufbauend auf unsere Umfrage wird ein Überblick über die technischen Aspekte, die klinischen Umstände und die Voraussetzungen
für MRT-Sicherheitsstandards bei Trägern künstlicher Herzklappen gegeben.
The indications for magnetic resonance imaging (MRI) on prosthetic heart valve recipients remain critical. A generalized
contraindication for MRI is doubtful. Some diagnostic questions such as interests in pathologies of the posterior cranial
fossa, spinal abscesses, and internal derangements for the knee, strongly recommend the advantages of MRI versus all other
radiological diagnostic techniques. MRI can directly affect patients with prosthetic valves in three ways by: 1) movement
or dislodgment of the prosthesis, 2) heating, and 3) arrhythmias induced by electric currents, and indirectly by distortion
of the image and its subsequent misinterpretation. Present literature that concerns the safety considerations of current values
appears to be incomplete. Therefore, a survey of twenty-five valve manufacturers with regard to compatibility, safety or
contraindication for MRI on their respective prosthetic heart valves was performed in 1998. Those manufacturers who distribute
most of the valves in Europe confirmed the safety of MRI. However, some gave their assurances based on inadequate data, or
assigned all responsibility to the physician. Some companies did not give any assurance for MRI safety or failed to respond
to our enquiry. Two valve manufacturers warned against performing MRI on certain prostheses. Based on our 1998 questionnaire,
the technical issues, the clinical circumstances, the prerequisites and criteria for and the definition of safety standards
for MRI on prosthetic heart valve recipients are presented in this paper.
Zeitschrift für Herz- Thorax- und Gefäßchirurgie 05/2000; 14(3):117-130.
ABSTRACT: Severe wound infection after open-heart surgery is a potentially life-threatening complication, which is mostly treated by re-operation with debridement, and insertion of closed irrigation drainage. Until now there is no consensus about the appropriate duration of irrigation therapy. Since the retrosternal irrigation cavity is likely to become continually smaller as the infection heals, this study was intended to answer the question, as to whether this process can be made visible by the use of contrast media radiography, and whether this information could be used to determine when an irrigation therapy can safely be discontinued. In 1997, 34 patients suffered from sternal wound healing disturbances which required re-operation at our institution (incidence = 0.97%). During the re-operation, a closed retrosternal irrigation drainage was inserted. Of the 34 patients contrast media radiography examinations were carried out on the first, 4th and 12th postoperative day (POD), which consisted of an antero-posterior x-ray of the chest after contrast media injection through each inlet tube. At POD 4 and 12 in the majority of cases, the retrosternal irrigation cavity became smaller when compared with the previous x-ray examination. Only in three of the non-survivors there was a huge irrigation cavity visible at the 12th POD, which sometimes even included the pleural cavity. We conclude that in patients with mediastinitis treated by insertion of a closed irrigation drainage, the retrosternally irrigated cavity seems to become smaller over the therapeutic course of treatment. This process can be visualized by contrast media radiography. Results from this examination should be included in decision making about the best time for discontinuation of the irrigation therapy.
Annals of thoracic and cardiovascular surgery: official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia 07/1999; 5(3):164-7. · 0.69 Impact Factor
ABSTRACT: Mediastinitis after cardiac surgery is a rare but life-threatening complication. The omentum is particularly well-suited for the treatment of severe sternal wound infections, because it contains large numbers of immunologically active cells that seem to be responsible for the high anti-infective activity of the omentum. The additional transposition of parts of the greater omentum into the thorax was discussed in the development of a protocol for the planned ATMI study, which will investigate the effectiveness of immunoglobulins in the treatment of severe sternal wound infections that require reoperation. We present two different points of view about whether omentopexy should be allowed within the study design.
The European journal of surgery. Supplement.: = Acta chirurgica. Supplement 02/1999;
ABSTRACT: During the consensus-based process of protocol development external experts were invited to comment on a proposal for a trial protocol on adjuvant immunotreatment of patients with wound infection after median sternotomy (ATMI). Controversies and arguments can be divided into five main areas: 1) rationale and objectives; 2) criteria for patient selection; 3) adjuvant treatment; 4) measures of efficacy; and 5) course and timetable of the study. We present and summarise the experts comments and criticism as well as the result of the final discussion of the study group with respect to these areas.
The European journal of surgery. Supplement.: = Acta chirurgica. Supplement 02/1999;