Efficacy trends of the acorn cardiac support device in patients with heart failure: a one year follow-up.
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
W Konertz
Publications and source records attributed to W Konertz.
[Left ventricular reduction surgery: pre- and postoperative evaluation by cine MRI].
AIM: To evaluate the role of cine magnetic resonance imaging (MRI) in the preoperative assessment and postoperative follow-up of patients undergoing left ventricular (LV) reduction surgery. PATIENTS AND METHODS: 6 patients with cardiomegaly were examined on a 1.5 T MR imager before and after LV reduction surgery. The heart was imaged along the short and long axes using a breath-hold ECG-triggered cine gradient-echo sequence for assessing ventricular and valvular morphology and function and performing volumetry (end-diastolic and end-systolic volumes, ejection fraction). RESULTS: Postoperatively, the mean ejection fraction increased from 21.7% to 33.4% and the end-diastolic and end-systolic left ventricular volumes decreased in all patients (304.0 and 252.5 ml before to 205.0 and 141.9 ml after surgery). Mean myocardial mass decreased slightly from 283.8 g to 242.7 g. Differences were significant for all parameters (p < 0.05). MRI allowed for the reliable assessment of post-operative valve morphology and yielded additional findings such as the presence of mitral valve insufficiency or ventricular thrombus. CONCLUSIONS: Cine MRI provides relevant information prior to left ventricular reduction surgery and reliably depicts functional and morphological changes in the early post-operative follow-up.
Aged↗
Influence of aminosteroid and glucocorticoid treatment on inflammation and immune function during cardiopulmonary bypass.
OBJECTIVE: During cardiopulmonary bypass, inflammation and immunosuppression is present. We measured circulating mediators and monocyte-based functions and tested the hypothesis that these variables are influenced by methylprednisolone (MP) or tirilazad mesylate (TM) treatment. DESIGN: Randomized, controlled, double-blind prospective trial. SETTING: A university hospital. PATIENTS: Thirty-nine patients scheduled for conventional coronary surgery with three-vessel disease. INTERVENTIONS: Preoperative application of MP (15 mg/kg) or TM (10 mg/kg) compared with placebo (PL). MEASUREMENTS AND MAIN RESULTS: Circulating proinflammatory markers including interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1, and C-reactive protein were all decreased by MP treatment but not by TM treatment. Whereas rapid increases in circulating anti-inflammatory IL-10 were superinduced by MP but not TM, plasma levels of IL-1RA and transforming growth factor beta were not altered by either treatment. Decreased ex vivo lipopolysaccharide-stimulated secretion of tumor necrosis factor alpha was prolonged after MP treatment but not after TM treatment. Perioperative stimulated secretion of IL-12 and interferon gamma was diminished in all groups, whereas ex vivo IL-1RA secretion tended to increase in all groups. Depression of monocyte surface expression of HLA-DR was significantly greater in patients treated with MP, whereas CD14 expression did not change. CONCLUSIONS: These data confirm that, during cardiopulmonary bypass, pro- and anti-inflammatory systems are activated at the same time, whereas monocyte-based immune functions are depressed. Treatment with MP abrogates proinflammatory mediators and induces a shift toward anti-inflammation at the cost of further functional monocyte deficits, whereas treatment with TM apparently has neither anti-inflammatory nor immunosuppressive actions in this setting.
Antioxidants↗
Use of desmopressin and erythropoietin in an anaemic Jehovah's Witness patient with severely impaired coagulation capacity undergoing stentless aortic valve replacement.
Cardiac surgery in Jehovah's Witness patients remains a challenge in the presence of concomitant congenital or acquired coagulation disorders and anaemia. We report a case of a 66-year-old female Jehovah's Witness suffering from severe calcified aortic valve stenosis requiring aortic valve replacement. The anaemic patient suffered from concomitant platelet dysfunction and deficiency of factors V and VII due to gammopathy of immunoglobulin G. The patient was preoperatively treated with recombinant erythropoietin in combination with folic acid and iron, which resulted in an increase of the haematocrit from 0.335 to 0.416 after 22 days of treatment. Haemostasis was improved by high dose aprotinin and additional desmopressin, which could be demonstrated to be effective by a preoperative test. The patients intra- and postoperative course was uneventful, her total chest tube loss was 130 ml, and she was able to be discharged without the need of any blood transfusions. The beneficial properties of erythropoietin and desmopressin in Jehovah's Witness patients are discussed.
Aged↗
Isolated hemoperfused heart model of slaughterhouse pigs.
A model of hemoperfused slaughterhouse pighearts is described providing a wide range of applications which leads to a reduction in animal experiments. The size of a pigheart, heart rate, coronary perfusion, metabolism, etc. are more comparable to conditions in patients than those in hearts of small laboratory animals. Global heart function can be assessed either by measuring stroke volume, ejection fraction, Emax etc. in the working model or by measuring intraventricular pressure with balloon catheters in the isovolumetric model. Regional cardiac function can be measured by sonomicrometry and ischemic and non-ischemic areas can be compared. Local metabolic changes are measurable as well with microdialysis. Cardiac function can be kept on any given functional level by infusion of norepinephrine in spite of the fact that functional parameters are lower without adrenergic drive in vitro than in vivo. Stable heart function can be maintained for several hours with only 500 to 1000 ml of blood because the blood is permanently regenerated by a special dialysis system. This model can be applied in many research projects dealing with reperfusion injuries, inotropic, antiarrhythmic or arrhythmogenic effects of certain drugs, immunological rejection, evaluation of imaging systems (NMR, echocardiography etc.) or cardiac assist devices.
Abattoirs↗
Influence of ischemic time and temperature on endothelial cell growth after transport.
BACKGROUND: The preparation of tissue-engineered material is a complex procedure. The possibility to transport tissue between laboratories without losing endothelial cell (EC) function was examined. METHODS: In 3 month old juvenile sheep (n = 6) a piece of vein (n = 14) was harvested and transported over 900 km to the tissue laboratory in Dulbecco's Modified Eagle's Medium (= DMEM). Vein material of each animal was transported at 4 degrees C (Group I, n = 6) and 25 degrees C (Group II, n = 8). EC growth potential was evaluated in function of the medium temperature and the ischemic time (between 8-24 hours). At the end of the first passage the EC of Group I and II were put together to save autologous serum of the sheep. After the 2nd passage the EC were cryopreserved at -80 degrees C to evaluate if EC viability would change. RESULTS: The growth potential of hypothermic Group I was equal in 16.7% (n = 1), higher in 33.3% (n = 2) and lower in 50% (n = 3) than Group II which had the same ischemic time during transport. Increase in ischemic time up to 24 hours showed no decrease of growth potential. Cryopreservation had no significant influence on EC viability. Viability at the end of the second passage, after recultivation and at the end of the third passage was 97.4% +/- 1.52, 95.5% +/- 1.34 and 94.5% +/- 1.08 respectively. CONCLUSIONS: In sheep there is no need to transport the EC at a temperature of 4 degrees C. Up to 24 hours growth potential and viability are maintained also at 25 degrees C.
Animals↗
A reliable test to detect impending pump failure during long-term support on the Novacor N100 Left Ventricular Assist System.
The Durastudy is a new surveillance protocol to detect impending pump failure in Novacor N100 Left Ventricular Assist Systems implanted for the long term. Our patient, a 54-year-old man with a history of dilated cardiomyopathy and contraindications for heart transplantation, received a Novacor pump in May 1995 and did not experience sustainable ventricular recovery during the subsequent 3 years. After more than 3 years of support, symptoms of pump wear were detected in this patient, through application of the Durastudy protocol. This enabled us to electively exchange the pump at 3.8 years. Our patient remained in New York Heart Association functional class I until he died in July 1999 of causes unrelated to the pump, after some 1,514 days of support. This, we believe, still constitutes a world record.
Heart-Assist Devices↗
Magnetic resonance imaging of stentless xenografts for reconstruction of right ventricular outflow tract.
The objective was to overcome allograft shortage during the Ross operation; stentless xenografts were carefully evaluated for hemodynamic behavior and valve deterioration during medium term follow-up. Between January 10, 1994 and January 4, 1996 nine adult patients (age 31-51 years) underwent aortic valve replacement with an autologous pulmonary valve and right ventricular outflow tract reconstruction with the Edwards Prima or Medtronic Freestyle xenograft. One patient was dead early and one late, both from noncardiac reasons. Forty-eight to 66 months follow-up was available for 7 patients and was performed with physical examination in the outpatient clinic, transthoracic echocardiography (TTE), and magnetic resonance imaging (MRI). Two patients received 29-mm valves and the remaining 27-mm valves. No reoperation became necessary during follow-up. Preoperative left ventricular ejection fraction ranged from 20% to 84%, median 61%, mean 59% +/- 18%. At latest follow-up left ventricular ejection fraction was 49% to 70%, median 57%, mean 58% +/- 8%. TTE showed no calcification of the xenograft wall or cusps. MRI revealed good autograft function with no evidence of stenosis in any patient. Four patients showed no and three trivial regurgitation. Right ventricular outflow tract-stenosis could not be seen in any patient. Calculated gradients of the xenograft valves ranged from 2 to 6 mm Hg, median 3 mm Hg (mean 3.1 +/- 2.4 mm Hg) and calculated EOA ranged from 2.0 to 4.0 cm(2), median 2.8 cm(2). MRI supported these findings and showed pliable xenograft cusps in all patients. Right ventricular function was well preserved in all patients. In adult patients right ventricular outflow tract reconstruction with stentless xenografts can be performed safely and intermediate-term results are encouraging. During medium-term (5-7 years) follow-up no calcification or deterioration of valve function occurred with excellent hemodynamic behavior.
Adult↗
Lack of calcification of tissue engineered heart valves in juvenile sheep.
The presence of viable endothelial cells may support longer durability and the absence of calcification in valve prostheses. This study shows the development of a tissue engineered heart valve, constructed from viable autologous endothelial cells on an acellular matrix and its evaluation in juvenile sheep. In 3-month-old sheep (n = 8) a piece of vein was harvested to culture autologous endothelial cells. A porcine acellular matrix was reendothelialized and implanted in juvenile sheep as pulmonary interposition. The valves were explanted after 1 week, 3 and 6 months. Examination was performed by X-ray, light microscopy, and atomic absorption spectrometry. Reendothelialization mean rate was 10.3 x 10(5) cells/cm(2) with a mean endothelial cell viability of 95.5% (0.98 x 10(5) cells/cm(2)). X-ray examination showed no cusp calcification at 1 week, 3 and 6 months, which was confirmed by light microscopy. Immunostaining for factor VIII demonstrated colonization of viable mature autologous endothelial cells on the heart valve after the seeding process. The atomic absorption spectrometry showed no significant increase of the calcium content after 3 (P value >.1) and 6 months (P value >.1) compared with nonimplanted tissue engineered heart valves. The tissue engineered valve showed no cusp calcification in the juvenile sheep after 3 and 6 months.
Animals↗
Clinical experience with autologous endothelial cell-seeded polytetrafluoroethylene coronary artery bypass grafts.
OBJECTIVE: Autologous endothelial cell seeding was used to improve the patency of 4-mm polytetrafluoroethylene vascular prostheses. METHODS: Since 1995, 14 patients with coronary artery disease received 21 autologous endothelial cell-seeded polytetrafluoroethylene vascular bypass grafts for coronary artery revascularization. The polytetrafluoroethylene grafts were seeded with the endothelial cells in a multiple step procedure, including cell culture techniques before coronary bypass operation. With the use of extracorporal circulation and cardioplegic arrest, a bypass operation was performed by means of conventional surgical techniques. RESULTS: After a mean postoperative follow-up of 27.7 months (range, 7.5-48 months), the graft patency rate is 90.5%. Follow-up angiograms of the aorta-coronary polytetrafluoroethylene bypass grafts showed patent bypasses in all cases except two. Angiograms of all 19 patent endothelial cell-seeded polytetrafluoroethylene bypass grafts showed a smooth luminal borderline without stenotic regions. The percutaneous transluminal angioscopic evaluation showed a glossy white and smooth endoluminal graft surface without any fibrin, platelet, or erythrocyte deposits. Intravascular ultrasonographic examinations confirmed the results. CONCLUSION: Patency of autologous endothelial cell-seeded 4-mm polytetrafluoroethylene vascular prostheses as coronary artery bypass grafts was much better than that of unseeded polytetrafluoroethylene grafts. Further evaluations and a larger population of patients will prove whether the encouraging patency will last.
Aged↗
Acute changes in functional and metabolic parameters following transmyocardial laser revascularization: an experimental study.
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.
Animals↗
[Surgical options in heart failure].
Explore the source record for details and available documents.
Arrhythmias, Cardiac↗
Mechanical circulatory support for one thousand days or more with the Novacor N100 left ventricular assist device.
Explore the source record for details and available documents.
Cardiac Catheterization↗
Early and intermediate results of left ventricular reduction surgery.
OBJECTIVE: Left ventricular reduction surgery is a new surgical option for treatment of end-stage cardiac dysfunction, and little is known about hemodynamics and outcome in the European heart failure population. We present our early results with this operation. METHODS: From January 1995 to September 1997, 30 patients (25 men, 5 women; mean age 61.2 years) underwent partial left ventriculectomy. The underlying disease was ischemic in 18 patients and idiopathic dilated cardiomyopathy in 12 patients. Preoperatively 23 patients were in New York Heart Association functional class IV and 7 were in class III. Mean cardiac index, stroke index and ejection fraction were 1.8 +/- 0.3 l/m2 per min, 23.5 +/- 5.1 ml/m2 and 19.3% +/- 6.8%, respectively. Associated procedures were coronary bypass in 18 patients, mitral valvuloplasty in one, aortic or mitral valve replacement in three, dynamic cardiomyoplasty in two, and left ventricular assist device implantation in 1. RESULTS: There were two early deaths: one from bleeding and one from anticoagulant-related cerebral hemorrhage. Regarding late deaths, one patient died from pneumonia 3 months after the operation and two died from dysrhythmia 4 and 17 months postoperatively. The estimated 1-year survival rate calculated by the Kaplan-Meier log-rank method was 85%. Mean cardiac index, stroke index, and ejection fraction rose significantly (P = 0.0001) to 2.9 +/- 0.51/m2 per min, 36.9 +/- 6.2 ml/m2 and 37.8% +/- 9.2%, respectively. Currently 26 patients are in New York Heart Association functional class I or II. CONCLUSIONS: Left ventricular reduction surgery improves objective and subjective parameters of cardiac performance significantly in early and intermediate follow-up. Randomized studies and carefully documented long-term results seem to be necessary to define the role of left ventricular reduction surgery.
Adult↗
Minimally invasive aortic valve replacement (AVR) compared to standard AVR.
OBJECTIVES: Minimally invasive cardiac surgery has been developed to offer patients the benefits of open heart operations with decreased pain and limited skin incision. A limited superior median sternotomy has been shown to provide a good exposure for aortic valve replacement (AVR) and good results. In this study we report the results of minimally invasive AVR compared to standard sternotomy AVR performed in the same period. METHODS: From May 1996 to January 1998, 86 patients received isolated aortic valve replacement by the limited superior median sternotomy(group 1). As a control group (group 2), 78 patients were enrolled who underwent isolated aortic valve replacements by standard sternotomy in the same period. RESULTS: Median ischemic time and median bypass time between the two groups showed no significant difference (P > 0.05). Median entire operation time in group 1 was obviously shorter than that in group 2 (P < 0.01). Median postoperative drainage was 229 ml in group 1, 369 ml in group 2. The difference between the two groups (P < 0.05) was significant. Median postoperative respiratory support time was 7.43 h in group 1, 11.26 h in group 2, with significant difference (P < 0.05). Median duration of hospital stay were 6.2 days in group 1, 9.4 days in group 2, with significant difference (P < 0.01). Reoperations for bleeding were two in group 1, four in group 2, superficial wound infection and sternum disruption occurred once in group 1 and four times in group 2. There were two hospital deaths respectively in the two groups (not procedure related). CONCLUSIONS: The limited superior median sternotomy provides good exposure to the left ventricular outflow tract, aortic valve, ascending aorta, and even to the mitral valve through the roof of the left atrium. Therefore it seems to be suitable for all kinds of aortic valve operations. Besides less pain, shorter skin incision, shorter respiratory support time and lower blood loss, it has more advantages as opening and closure of the sternum is faster; decreasing infection and disruption of the sternum, and finally decreasing the time required for hospitalization and recovery.
Adult↗
Recovery from end-stage ischemic cardiomyopathy during long-term LVAD support.
A patient with ischemic cardiomyopathy and extremely reduced left ventricular function (left ventricular ejection fraction=0.10) presented to our institution for cardiac transplantation. Because of his worsening condition he was placed on the Novacor left ventricular assist device. During 3 months of support his left ventricular function recovered and he successfully underwent percutaneous transluminal coronary angioplasty and minimally invasive direct coronary artery bypass grafting procedures; subsequently he could be weaned from the left ventricular assist device and discharged. The patient is no longer considered for cardiac transplantation.
Angioplasty, Balloon, Coronary↗
Fontan modification for subsequent non-surgical Fontan completion.
OBJECTIVE: Establishment of Fontan circulation in complex univentricular hearts often requires several surgical procedures. We developed a procedure which maintains the advantages of a staged approach, however, during the initial surgery additional preparatory measures are performed to allow subsequent non-surgical Fontan completion. METHODS: The operation is a lateral baffle Fontan procedure. The baffle bears multiple perforations to allow the inferior vena cava blood to drain into the systemic atrium. Total cavopulmonary connection is performed as usual and the cardiac end of the superior vena cava is subtotally banded. Formally the operation establishes a bi-directional Glenn physiology. During subsequent catheter intervention the banding of the superior vena cava is dilated and the holes in the baffle are closed with appropriate devices. RESULTS: From April 1994 to December 1995, 18 children having at least two risk factors for Fontan operation received the above described operation. Ages ranged from 3 months to 15 years. Ten patients had one or more previous operations. Bypass time ranged from 86 to 128 min and cross clamp time from 14 to 79 min. O2 saturation after discontinuation of cardiopulmonary bypass was 76% (70-81%). The postoperative recovery of all patients was rapid with early extubation (mean 6 h) and discharge to the ward the morning of the first postoperative day. One patient died. No fluid retention as pericardial, pleural or abdominal fluid effusions occurred. At discharge O2 saturation was 77% (75-82%). In thirteen children successful conversion to total cavopulmonary connection with interventional debanding of the superior vena cava and closure of the fenestrations was performed. After a hospital stay of only a couple of days the children were discharged with normal O2 saturation after Fontan completion. CONCLUSIONS: We suggest that this modification of the staged Fontan procedure reduces the need for surgical interventions by applying balloon angioplasty and occluder technology to this unique subset of patients.
Adolescent↗
Centrifugal pumps as left ventricular assist for coronary revascularization on a beating heart.
During recent years, coronary bypass surgery has progressed toward minimizing invasiveness. One important feature of this approach is performing surgery on a beating heart. During the crucial phase of such surgery, the mechanical support of the heart with a left ventricular assist device (LVAD) is a possible option. During the period from October 1, 1994 until June 30, 1997, we employed a centrifugal pump system in 118 cases of coronary artery bypass graft (CABG) procedures with LVAD support (mechanically supported CABG [SUPPCAB]). A total of 179 distal anastomoses with an average of 1.5 +/- 0.5 coronary anastomoses per patient was performed. Three types of pumps were used: 23 BioPump, 87 Isoflow, and 8 Capiox systems. The median time on mechanical support was 44 min (range, 16-116 min). The mean flow rate during support time was 3.5 +/- 0.8 L/min, which results in a calculated flow of 1.7 +/- 0.6 L/min/m2 body surface area (BSA). The average flow was 3.2 +/- 0.8 L/min with the BioPump and 3.7 +/- 0.8 L/min with the Isoflow pump, respectively (p < 0.01). The mean arterial pressure during mechanical support was 75 +/- 12 mm Hg. In 2 patients, the pump system was kept running postoperatively in the ICU. Eight of the patients received operations under resuscitation or in cardiogenic shock. Nine (7.9%) of the patients did not survive the early postoperative phase. For coronary revascularization of the anterolateral and diaphragmatic parts of the heart, the SUPPCAB procedure is feasible with excellent mechanical support of the heart by centrifugal pumps. Especially in high risk cases, this procedure can be recommended.
Adult↗