PubMed Health⌕ Search

Biomedical subjects

F Beyersdorf

Publications and source records attributed to F Beyersdorf.

At least 19 recordsLinked to original sources
PubMed1998

[Bypass perforation by stent implantation: complication management. A case report].

We describe a case-report on an perforation of an aorto-coronary venous bypass graft, a complication induced by a stent-implantation. Perforations of coronary arteries are rare, however, for interventional cardiologists well-known complications. This case report is of special interest (1) because the perforation did not occur in a coronary artery but rather in an eight year old venous bypass graft and (2) because the perforation was induced by a stent-implantation. In addition, this case report describes in great detail the management of vessel perforation: several invasive methods contributed to minimize pericardial effusion and to stabilize the patient until surgical revision could be performed.

Aged↗
PubMed1998

[Treatment strategies in therapy refractory angina pectoris: transmyocardial laser revascularization].

BACKGROUND: Does transmyocardial laser revascularization (TMLR) as a new surgical technique for treating patients with otherwise intractable angina pectoris improve myocardial perfusion or contractility? METHODS: Sixty-seven patients transferred for TMLR were evaluated by clinical evaluation, treadmill stress testing, echocardiography, ventriculography, and hybrid positron emission tomography preoperatively and in patients treated with TMLR at 6 and 12 month follow up. Hemodynamic assessment and clinical evaluation were performed perioperatively. RESULTS: In 28/67 cases (42%) CABG, in 9/67 patients (13%) CABG in combination with TMLR (combined group), and in 30/67 patients (45%) only TMLR (sole group) were performed. Perioperative mortality in the sole group was 13%, in the combined group zero, and in the CABG group 11%. In all groups a significantly improved clinical status (p < or = 0.01) 1 week postoperatively and in TMLR groups also at 6 and 12 months was observed. In the TMLR groups treadmill tolerance (p < 0.05) improved, although function, perfusion, and metabolism did not change significantly at the 6 and 12 month follow up. CONCLUSION: TMLR significantly improves clinical status and treadmill stress tolerance, but does not change function, perfusion, and metabolism.

Aged↗
PubMed1998

Histologic findings of transmyocardial laser channels after two hours.

Histologic examination of the human myocardium has been performed several days, weeks, and months after transmyocardial laser revascularization. We performed microscopic examinations 2 hours postoperatively. In addition to the patent channel (diameter, 1 mm) and a 1-to 2-mm rim of necrosis, a 1- to 3-mm zone of myofibrillary degeneration was found. This additional reversible injury immediately after transmyocardial laser revascularization could explain the higher mortality rate in patients with reduced left ventricular function.

Aged↗
PubMed1998

Transmyocardial laser revascularization (TMLR) in patients with unstable angina and low ejection fraction.

OBJECTIVE: Does perioperative use of the intraaortic balloon pump (IABP) improve the postsurgical outcome of patients presenting with endstage coronary artery disease, unstable angina and low ejection fraction transferred for transmyocardial laser revascularization (TMLR)? METHODS: TMLR, as sole therapy combined with the perioperative use of an intraaortic balloon pump has been assessed in seven patients with endstage coronary artery disease, unstable angina and low ejection fraction (EF < 35%). Six out of seven patients had signs of congestive heart failure. These patients are compared with 23 patients with endstage coronary artery disease, stable angina and EF > 35%, who were treated with TMLR as sole therapy without the use of IABP. The creation of transmural channels was performed by a CO2-laser. All patients were evaluated by hybrid positron emission tomography (perfusion SPECT and viability PET) and ventriculography preoperatively. Echocardiography, clinical status and hemodynamic assessment by Swan Ganz catheter were performed perioperatively. RESULTS: The perioperative mortality of this combined procedure (TMLR and IABP) was zero. Three out of seven patients had pneumonia with complete recovery. Swan Ganz catheter examinations showed deterioration of LV-function after TMLR intraoperatively and improvement after 2 h and further after 6 h on ICU (P < 0.05). In contrast, a decrease of LV-function in sole TMLR patients with an EF > 35%) has not been observed. Patients with EF < 35% needed the IABP for 2.3 days and moderate dose catecholamines for a mean of 3.0 days. The postoperative EF and resting wall motion score index (WMSI) of all analysed LV segments (evaluated by echocardiography) did not change compared to baseline (EF 31.3+/-2.6 preop. to 32.8+/-3.2 postop.; WMSI: 1.75+/-0.14 at baseline to 1.71+/-0.17 postop.). The average Canadian Angina Class at the time of discharge decreased from 4.0+/-0 (baseline) to 2.3+/-0.5 (P < 0.05) and the NYHA-Index from 3.9+/-0.3 to 2.7+/-0.5. No patient had signs of angina pectoris, whereas two patients still had signs of congestive heart failure. CONCLUSIONS: The reported data support our concept to start IABP preoperatively in patients with reduced LV contractile reserve in order to provide cardiac support during the postoperative phase of reversible decline of LV-function induced by TMLR.

Aged↗
PubMed1998

Endothelium-dependent and endothelium-independent flow reserve in vascular regions supplied by the internal mammary artery before and after bypass grafting.

OBJECTIVE: It was the goal of this study to compare endothelium-dependent and endothelium-independent flow reserve in vascular regions supplied by the left internal mammary artery before and after bypass graft surgery. METHODS: The native internal mammary artery in situ was investigated in 13 patients (age 61.8 +/- 8.0 years) with angiographically proven coronary artery disease. The internal mammary artery after bypass grafting was investigated in ten patients (age 60.8 +/- 7.3 years) 3.5 +/- 2.8 years after the operation. Flow reserve was evaluated endothelium-dependent with acetylcholine (ACh 25 and 50 microg i.c.) and endothelium-independent with nitroglycerin (NTG 0.3 mg i.c.) followed by papaverin (10 mg i.c.). Flow indices were calculated from intraluminal Doppler blood flow velocity measurements and the vascular cross-sectional area as determined by quantitative angiography. An index for vascular resistance was defined as the ratio of pressure gradient and resting or peak flow. RESULTS: After endothelium-dependent stimulation with acetylcholine 25 microg (50 microg), flow in the internal mammary increased by 352.3 +/- 152% (412 +/- 145%) before surgery, whereas it increased only by 213 +/- 134% (193 +/- 120%) after surgery (P < 0.05). Endothelium independent stimulation with papaverin resulted in a flow increase of 391 +/- 234% before surgery vs. 315 +/- 135% after surgery (n.s.). The resistance index decreased after endothelium-dependent stimulation with acetylcholine 25 microg(50 microg) to 35 +/- 16.8% (28 +/- 8.9%) before surgery, whereas it decreased only to 59 +/- 26% (72 +/- 43%) after surgery (P < 0.05). Endothelium independent stimulation with papaverin resulted in a decrease of the vascular resistance index to 31 +/- 14% before surgery vs. 32 +/- 14% after surgery (n.s.). CONCLUSION: Vascular regions supplied by the internal mammary artery as a graft demonstrate a significantly reduced endothelium-dependent flow reserve but a preserved endothelium-independent flow reserve as compared to vascular regions supplied by the native internal mammary artery. The selective decrease in endothelium-dependent flow reserve may be due to microvascular changes in the myocardial region supplied by the internal mammary artery after bypass grafting.

Aged↗
PubMed1998

Transmyocardial laser-revascularization: experimental studies on prolonged acute regional ischemia.

OBJECTIVE: This experimental study in pigs was undertaken to answer the question whether TMLR after acute myocardial infarction may improve regional myocardial perfusion, left ventricular function and diminish myocardial necrosis in the area at risk. METHODS: Thirty open-chest anesthetized pigs were observed for 6 h, six pigs served as controls. In 24 pigs, occlusion of the left anterior descending artery (LAD) beyond the first diagonal branch was performed: seven pigs had LAD occlusion only (ischemia group), and 17 pigs were treated by TMLR (using a CO2-laser, energy: 40 J) prior to coronary occlusion; nine pigs received one laser channel (1 mm diameter) per cm2 (laser group 1) and eight pigs two channels per cm2 in the LAD territory (laser group 2). Regional myocardial blood flow by microspheres, function (franc starling curves), histochemical assessment (triphenyl tetrazolium chloride, TTC and histology), were performed. RESULTS: The lased pigs were less prone to ventricular fibrillation (laser group 2, 38%; laser group 1, 56%; ischemic group, 100%; P < 0.05), and showed a significant smaller area of necrosis (TTC) in the area at risk (laser group 1, 23%; laser group 2, 14%; vs. ischemia group, 31%; P < 0.01). There was no significant difference between laser-treated and ischemia hearts regarding the amount of blood flow into the infarcted LAD region and the maximal left ventricular stroke work index after 6 h (P = n.s). Regional myocardial blood flow: ischemia group, 4 +/- 5 ml/100 g/min; laser group 1, 3 +/- 10 ml/100 g/min, and laser group 2, 2 +/- 10 ml/100 g/min; maximal left ventricular stroke work index: ischemia group, 1.8 mJ/g; laser group 1, 2.1 mJ/g and laser group 2, 2.1 mJ/g. CONCLUSIONS: This model of acute regional ischemia demonstrates that CO2-laser revascularization diminish significantly the incidence of ventricular fibrillation and necrosis in the area at risk, and does not change regional myocardial perfusion and global left ventricular function. This experiment indicates that TMLR may be an alternative in treating advanced ischemic heart disease.

Animals↗
PubMed1998

Orthotopic transplantation of pig hearts harvested after 30 min of normothermic ischemia: controlled reperfusion with blood cardioplegia containing the Na+-H+-exchange inhibitor HOE 642.

OBJECTIVES: The aim of our study was to develop a surgical technique for a successful transplantation of hearts harvested after 30 min of normothermic ischemia without donor pretreatment. Successful transplantation of ischemic compromised hearts could help to expand the severely limited donor pool. We used the pig model because this species is very susceptible to myocardial ischemia. Na+-H+-exchange (NHE) inhibitors have shown excellent protective properties in several in vitro and in vivo models of myocardial ischemia and reperfusion. METHODS: In group I (n=12) hearts were harvested after 30 min of normothermic ischemia following cardiac arrest induced by exsanguination. Hearts were perfused with warm blood cardioplegia and transplanted orthotopically. In group II (n=9) controlled reperfusion with cold leucocyte-depleted blood cardioplegia was performed after 30 min of normothermic ischemia. In group III (n=8) the same procedure was performed as in group II but blood cardioplegia contained 1 mmol/l HOE 642. RESULTS: In group I massive myocardial oedema was observed and none of the animals could be weaned from cardiopulmonary bypass (CPB). In contrast, all animals in groups II and III could be weaned from CPB with low dose inotropic support. In groups II and III the contractility of the hearts, expressed as maximal left and right ventricular stroke work index was significantly impaired after transplantation as compared with the preoperative value. Supplementation of blood cardioplegia with HOE 642 resulted in a significantly better recovery of the LVSWImax (Group II vs. III). CONCLUSIONS: Successful transplantation of pig hearts is possible after 30 min of normothermic ischemia without donor pretreatment if a controlled reperfusion with cold leucocyte-depleted blood cardioplegia is performed. HOE 642 given during reperfusion only improves posttransplant left ventricular function.

Animals↗
PubMed1998

Clinical experience with blood cardioplegia.

Since its initial description, blood cardioplegia has become the preferred tool to arrest the heart for open heart surgery in both children and adults. This shift from crystalloid-type cardioplegia to blood cardioplegia occurred because experimental and clinical studies demonstrated superior protection of the arrested myocardium by blood cardioplegia. In this article we review and describe the different strategies and protocols which have evolved for the use of blood cardioplegia under different conditions. The protocols differ in the composition of the crystalloid component of the solution, the direction of delivery (antegrade, retrograde, or both), and/or the temperature of the solution. In order to maxime myocardial protection, specific protocols for the administration of blood cardioplegia have been designed for specific clinical conditions. We further define the indications for the use of the different protocols. Our own clinical experience with blood cardioplegia is corroborated with the concepts and results described in the literature. We conclude that blood cardioplegia is 1.) an effective way to safely arrest the myocardium for cardiac operations, 2.) affords excellent myocardial protection, and 3.) allows for quick recovery of contractile function upon reperfusion.

Adult↗
PubMed1997

Endoluminal stent-grafts for infrarenal abdominal aortic aneurysms.

BACKGROUND: The treatment of aortic aneurysms with endovascular stents or stent-graft prostheses is receiving increasing attention as an alternative to major abdominal surgery. To define the clinical value of this technique, we prospectively studied the use of stent-graft endoprostheses made of nitinol and covered with polyester fabric for the treatment of infrarenal abdominal aortic aneurysms. METHODS: We treated a total of 154 patients at three academic hospitals. Twenty-one patients with aortic aneurysms not involving the aortic bifurcation received straight stent-grafts, and 133 patients with aortic aneurysms involving the bifurcation and the common iliac arteries received bifurcated stent-grafts. After a unilateral surgical arteriotomy, the endoprostheses were advanced through the femoral arteries and placed under fluoroscopic guidance. Computed tomography and intraarterial angiography were performed during an average follow-up of 12.5 months. RESULTS: The primary success rate, defined as complete exclusion of the abdominal aortic aneurysm from the circulation, was 86 percent in the group receiving straight grafts and 87 percent in the group receiving bifurcated grafts. In three patients the procedure had to be converted to an open surgical operation. Minor (n=13) or major (n=3) complications associated with the procedure (including 1 death) occurred in 10 percent of the patients. All patients had a postimplantation syndrome, with leukocytosis and elevated C-reactive protein levels. CONCLUSIONS: Our results suggest that endovascular treatment of infrarenal abdominal aortic aneurysms is technically feasible and can effectively exclude abdominal aortic aneurysms from the circulation. With further refinement, endoluminal repair may emerge as an interventional strategy to treat infrarenal aortic aneurysms, especially in patients at high surgical risk.

Adult↗
PubMed1997

Ca(2+)-dependent and Ca(2+)-independent regulation of contractility in isolated human myocardium.

UNLABELLED: Changes in contractile force of the myocardium may depend on changes in the intracellular Ca2+ concentration, changes in the responsiveness of the myofibrils for Ca2+, or a combination of both. We investigated in isolated muscle strip preparations from human nonfailing and endstage failing hearts the influence of physical (changes in preload, stimulation rate, or rhythm), and pharmacological interventions (alpha- or beta-adrenoceptor-stimulation, endothelin) on developed force of contraction and the corresponding intracellular Ca2+ transients. METHODS: Isometric contraction, electrical stimulation, 37 degrees C. Simultaneous registration of force of contraction and intracellular Ca2+ transients (aequorin method). RESULTS: Increases in preload, alpha- and endothelin-receptor stimulation resulted in increases in force of contraction without increasing aequorin light emission. Increasing stimulation rate or increasing rest intervals resulted in parallel increases (nonfailing myocardium) or decreases (failing myocardium) of force of contraction and aequorin light emission. beta-Adrenoceptor-stimulation exerted inotropic and lusitropic effects in human failing myocardium associated with a large, overproportional increase in aequorin light emission. CONCLUSION: The human heart regulates intrinsic contractility via several subcellular mechanisms. Increases in preload (Frank-Starling-mechanism) and alpha- or endothelin-receptor-stimulation enhance myocardial contractility by increasing the Ca2+ responsiveness of the myofilaments; rate- and rhythm-dependent modulation of the contractile state directly depend on changes in the intracellular Ca(2+)-transients; beta-adrenoceptor stimulation results in an overproportional large increase in intracellular Ca2+ transients, probably due to additional cAMP-dependent Ca(2+)-desensitizing effects on the level of the myofibrils.

Calcium↗
PubMed1997

[Batista partial left ventricular resection in terminal heart failure].

Congestive heart failure is a clinical condition with a high mortality. Medical therapy has improved the clinical course of these patients considerably in recent years. Numerous surgical interventions such as high risk coronary bypass surgery, resection of left ventricular aneurysms, heart valve replacement and cardiac transplantation became accepted therapeutical options. More recently, transmyocardial laser revascularization, implantation of mechanical assist devices, implantable cardioverters/defibrillators and dynamic cardiomyoplasty were introduced into clinical practice and are still under evaluation. For most patients suffering from congestive heart failure cardiac transplantation is the only therapeutical option. However, age of the patients, decreasing number of donors, mortality on the waiting list, high morbidity under immunosuppressive therapy and graft vasculopathy characterize the problems of this therapeutical strategy. The brasilian cardiac surgeon Randas Batista therefore has introduced a new organ preserving surgical technique. First reports on "partial left ventricular resection" for patients with end-stage cardiac failure and dilated ventricles are promising. The possible importance of this new surgical technique implies that precise clinical and scientific evaluation are imperatively needed. In this review we present the surgical procedure, published data on clinical outcome and hemodynamic changes and possible indications for this new technique. The few data which have been published so far might indicate that there is an acceptable perioperative mortality associated with a symptomatic improvement. However, intermediate and long-term follow-up data are not available, and refinements in the surgical technique are necessary.

Cardiomyopathy, Dilated↗
PubMed1997

[Successful treatment of fulminant myocarditis with the biventricular MEDOS Assist System (MEDOS HIA-VAD)].

BACKGROUND: Successful weaning from biventricular mechanical support with full recovery of the myocardial function is extremely rare in fulminant myocarditis. We report on our experience with the new MEDOS HIA ventricular assist device. METHODS AND RESULTS: We used the MEDOS assist system to support a 30-year-old woman with profound circulatory impairment caused by acute myocarditis. The device provided adequate hemodynamics and recovery of myocardial function. Despite anticoagulation therapy we had to change either the left or right ventricular pump chamber because of clot formation on the surface of the outflow tract. On the 14th postoperative day a surgical reintervention was necessary for bleeding from the cannulation site of the pulmonary artery. After 17 days the myocardial function had recovered and we could remove the assist system. The following parameters were measured before implantation of the MEDOS assist system and after weaning from circulatory support: ejection fraction 15 vs. 45%, cardiac index 0.7 vs. 2.6 L/min/m2, arterial pressure (systolic/diastolic/mean) 81/55/66 vs. 113/66/82 mm Hg, pulmonary artery pressure 33/25/29 vs. 34/20/28 mm Hg, pulmonary capillary wedge pressure 24 vs. 19 mm Hg. CONCLUSIONS: Despite severe cardiac failure in fulminant myocarditis requiring biventricular mechanical support full recovery of the myocardium is possible.

Adult↗
PubMed1997

["Myxoma syndrome"--a "benign" disease with "malignant" course].

We are reporting on a 36 year-old woman who presented with recurrent cardiac myxomas over a period of nine years. Two of the tumors typically originated in the left atrium and one in the right atrium. Tumor embolization was the presenting symptom twice, leading to reversible cerebral ischemia and minor pulmonary embolism, respectively. The third tumor remained asymptomatic and was detected during routine echocardiographic examination. Based on a positive family history of cardiac tumors, a facially pronounced hyperpigmentation of the skin and the presence of a thyroid adenoma, the diagnosis of a "myxoma syndrome" was established. Patients with "myxoma syndrome" are generally younger than their counterparts with "sporadic myxoma" (mean age at diagnosis 25 vs. 56 years) and have a high frequency of unusual skin freckling (68%). Familial clustering of cardiac myxomas is also frequent (25%). The tumors may be located in any of the cardiac chambers (87% in the atrias, 13% in the ventricles, 50% at multiple sites simultaneously) and have relatively high (18%) 5-year recurrence rate after surgical excision. Since the clinical signs of cardiac tumors are non-specific, diagnosis essentially relies on cardiac imaging by echocardiography, computer tomography, or angiography. The superiority of transesophageal echocardiography is emphasized in this report.

Adult↗
PubMed1997

MEDOS HIA-VAD biventricular assist device for bridge to recovery in fulminant myocarditis.

Successful weaning from biventricular mechanical support with full recovery of the myocardial function is extremely rare in fulminant myocarditis. We report on our experience with the MEDOS HIA-VAD ventricular assist device. The device worked for 17 days and provided adequate hemodynamics. Despite anticoagulation therapy, we had to change both ventricles because of clot formation on the surface of the outflow tract. After 17 days the myocardial function had recovered and we could remove the assist system.

Acute Disease↗
PubMed1997

Minimal-invasive, video-assisted vein harvesting for cardiac and vascular surgical procedures.

Harvesting of the saphenous vein is a routine procedure in coronary and peripheral vascular surgery. It is usually performed using a continuous long skin incision. Minor complications are reported in up to 24% (hematoma, wound dehiscence, infection, pain) and major problems necessitating surgical interventions (bleeding, abscess) in less than 1%. These complications lead to a prolonged hospital stay. To reduce these complications we have used a new endoscopic, video-assisted technique in 17 patients. Harvesting of the total length of the saphenous vein is possible with only one 2-3 cm long incision proximally the knee joint. We conclude that this technique is safe, may reduce the morbidity of saphenous vein harvesting and is associated with a perfect cosmetic result.

Coronary Disease↗
PubMed1997

Pulmonary artery banding with a novel percutaneously, bidirectionally adjustable device.

Pulmonary artery banding is commonly performed as a palliative procedure in complex congenital heart disease, when pulmonary blood flow is increased. However, the hemodynamics may change postoperatively requiring readjustment of the band, which may necessitate a second operation. We report a new system for pulmonary artery banding which allows precise placement of the band intraoperatively, as well as bidirectional percutaneous adjustment of the band postoperatively. Via left lateral thoracothomy the new device was implanted without complications into a neonate with congestive heart failure due to tricuspid atresia (IIc) and coarctation of the aorta. Although optimal placement of the band had been achieved intraoperatively the band had to be tightened 25 h after the operation and released 85 h after the operation in order to optimize hemodynamics. The bidirectionally adjustable device for banding of the pulmonary artery is superior to previously used devices with either no or unidirectional adjustability of the band because it is safe and easy to implant and has the potential to reduce the number of reoperations associated with this type of procedure.

Cardiac Surgical Procedures↗