Manfred Dahm - Academia.edu (original) (raw)
Papers by Manfred Dahm
The Journal of Thoracic and Cardiovascular Surgery, Nov 1, 2002
Cardioprotective effects of the serine protease inhibitor aprotinin after regional Objective: Ear... more Cardioprotective effects of the serine protease inhibitor aprotinin after regional Objective: Early coronary reperfusion of the ischemic myocardium is a desired therapeutic goal to preserve myocardium. However, reperfusion itself contributes to an additional myocardial injury (ie, reperfusion injury), which has been attributed to neutrophil infiltration with subsequent release of proteases and oxygen-derived radicals. We studied the effects of the serine protease inhibitor aprotinin (Trasylol) on myocardial ischemia and reperfusion in a rat model.
The Journal of Heart Valve Disease, Nov 1, 2006
BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the efficacy of three different... more BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the efficacy of three different anticoagulants in preventing thrombus formation on mechanical heart valves, using an in-vitro system.METHODS: Blood samples (470 ml) were taken from young and healthy male volunteers and anticoagulated with unfractionated heparin (UFH; n=18), low molecular-weight heparin (LMWH; n=18) or fondaparinux (n=16). Bileaflet mechanical heart valves were placed in a new device--the 'Thrombosis Tester'--and exposed in a continuous circulation at a rate of 80 beats per min to the anticoagulated blood samples for a total exposure time of 60 min. Results for thrombus weight were skewed distributed and presented as log-transformed values.RESULTS: The weight of each valve was measured before and after 1 h of perfusion; subsequent mean (+/-SD) thrombus weights were 0.739 +/- 0.573 g for UFH, 0.789 +/- 0.099 g for LMWH, and 0.934 +/- 0.145 g for fondaparinux (p = 0.397 for comparison of all groups by ANOVA). Electron microscopy showed concordant results with regard to thrombus formation on heart valve surfaces.CONCLUSION: Fondaparinux and LMWH were as effective as UFH in preventing thrombus formation on mechanical heart valves in vitro. The 'Thrombosis Tester' proved to be a new, unique instrument for investigating the ability of anticoagulants to prevent valve thrombosis on mechanical heart valves under in-vitro conditions.
Journal of Pharmacology and Experimental Therapeutics, Jul 1, 1998
Myocardial injury after ischemia (I) and reperfusion (R) is related to leukocyte activation with ... more Myocardial injury after ischemia (I) and reperfusion (R) is related to leukocyte activation with subsequent release of cytokines and oxygen-derived free radicals as well as complement activation. In our study, the cardioprotective effects of exogenous C1 esterase inhibitor (C1 INH) were examined in a rat model of myocardial I ϩ R (i.e., 20 min ϩ 24 hr or 48 hr). The C1 INH (10, 50 and 100 U/kg) administered 2 min before reperfusion significantly attenuated myocardial injury after 24 hr of R compared to vehicle treated rats (P Ͻ .001). Further, cardiac myeloperoxidase activity (i.e., a marker of PMN [polymorphonuclear leukocyte] accumulation) in the ischemic area was significantly reduced after C1 INH treatment compared to vehicle treated animals (0.81 Ϯ 0.1, 0.34 Ϯ 0.13, 0.13 Ϯ 0.1 vs.
Herz, 2004
Hintergrund und Ziel: Kalzifikation und Degeneration stellen die Hauptprobleme im Langzeitverlauf... more Hintergrund und Ziel: Kalzifikation und Degeneration stellen die Hauptprobleme im Langzeitverlauf nach Implantation biologischer Prothesen dar. In Vorläuferstudien konnte gezeigt werden, dass sich durch eine Bedeckung der Oberfläche des Biomaterials mit Zellen eine Reduktion der Calciumaufnahme erzielen lässt. Allerdings ist eine vollständige Oberflächenbesiedelung schwer zu erreichen. Daher wurde das Konzept der kovalenten Bindung von Polymeren an die Oberfläche des Implantats und der sich daran anschließenden Zellbesiedelung entwickelt. Ziel der aktuellen Studie war die Austestung verschiedener Polymere auf ihre Fähigkeit, die Adhärenz humaner Zellen zu fördern, so dass sich ein intakter Monolayer ausbildet. Material und Methodik: Zehn an Glas gebundene ultradünne Polymere mit unterschiedlichen physikochemischen Eigenschaften wurden mit humanen Endothelzellen und vier von diesen zehn Polymeren mit Fibroblasten besiedelt. Das Wachstumsverhalten wurde mit dem der Zellen auf einer Glasoberfläche verglichen. Das Wachstum wurde photographisch im Phasenkontrastmikroskop und in der Elektronenmikroskopie dokumentiert.
Herz, 2004
Background and Purpose: Cardiac troponins have shown to be specific markers of myocardial injury.... more Background and Purpose: Cardiac troponins have shown to be specific markers of myocardial injury. The aim of this prospective study was to compare patterns and kinetics of troponin I and T after coronary artery bypass grafting (CABG) with or without perioperative myocardial infarction (PMI). Patients and Methods: 119 patients (male/female: 96/23, age 64 ± 10 years) underwent first time elective
Bio Medical Materials and Engineering, Feb 1, 2004
Reoperation of aldehyde tanned bioprotheses due to calcific degeneration remains their major draw... more Reoperation of aldehyde tanned bioprotheses due to calcific degeneration remains their major drawback. Based on experiments studying mechanisms and factors that influence the time phase, extent and progression of calcification and evaluating the efficiency of anticalcification treatments and the effects of surface seeding with vital cells a new concept to avoid calcification emerged: masking aldehyde-residues with a covalently bound polymer that supports surface cell seeding. Different covalently bound polymers were tested for their suitability to grow cells. Dense cell growth was achieved on some polymers but without correlation to physico-chemical properties. Ultrathin coating of biological materials appears a promising approach to achieve lining with vital cells.
Thorac Cardiovasc Surg, 1987
In a total of 30 operations the mitral valve was reconstructed in 18, the tricuspid valve in 11, ... more In a total of 30 operations the mitral valve was reconstructed in 18, the tricuspid valve in 11, and both AV-valves in one patient. The result of reconstruction was tested first in the open arrested heart by injection of crystalloid solution into the appropriate ventricle either through the reconstructed valve or one of the great arteries. Upon termination of cardiopulmonary bypass the valve function was examined in the beating heart by means of transesophageal contrast echocardiography (TEE). For visualization 0.5-1.0 cc of agitated Gelifundol was injected into the ventricle. In 22 patients open testing as well as echocardiographic visualization showed identical and good operative results. In 6 patients TEE revealed mild insufficiency, but no further surgery was done. In three patients with mitral valve repair, contrast-echocardiography showed severe insufficiency, which had not been detected during cardiac arrest. In these patients changes in the level of the subvalvular apparatus caused systolic dislocation of the leaflets and massive reflux. Because of these findings definive valve replacement was performed in the same operation. Intraoperative TEE is a simple, safe and reliable method für assessment of AV-valve repair, thereby motivating the surgeon towards valve preservation and improving the outcome of valve surgery.
The American Journal of Surgical Pathology, Mar 1, 2010
Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypi... more Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypic features of FDCs. It occurs primarily in lymph nodes but also in extranodal sites. So far, there have been no reports on FDC sarcoma associated with myasthenia gravis. In the following we will present a case of an FDC tumor of the mediastinum associated with paraneoplastic myasthenia gravis in a 39-year-old man. The tumor contained a major proportion of immature T cells, which may be connected to this patient's very unusual clinical presentation with autoimmune phenomena. Extranodal FDC sarcomas still seem hardly noticed, and their clinical and pathologic characteristics remain to be better defined.
Langenbecks Arch Surg, 1987
In 17 patients (10 patients with mitral insufficiency, 5 patients with tricuspid regurgitation, 2... more In 17 patients (10 patients with mitral insufficiency, 5 patients with tricuspid regurgitation, 2 patients with mitral stenosis) the result of valve reconstruction was evaluated by intraoperative two-dimensional transesophageal contrast-echocardiography (TEE). Therefore, 1-2cc of an agitated contrast-medium (Gelifundol) were injected into the left or right ventricle. The result of reconstruction was assessed by the extent of regurgitant microbubbles into the left or right atrium. A successful valve repair could be demonstrated in 15 patients without or with only minimal regurgitation of contrast-fluid. In one patient residual severe mitral insufficiency after valve reconstruction could only be detected when valve function was examined by contrast-TEE in the beating heart. An intraoperative decision for valve replacement was made. In another patient, mild to moderate residual mitral incompetence was shown; no further surgical intervention was done. By TEE the function of reconstructed valves can be examined under physiological conditions in the beating heart. Surgeons can obtain additional intra-operatively information and certainty about the result of reconstruction and an early decision for valve replacement can be made if necessary.
Thorac Cardiovasc Surg, 2010
Herz, Jun 1, 2004
Calcific degeneration with the resulting need for operative replacement remains the major drawbac... more Calcific degeneration with the resulting need for operative replacement remains the major drawback of bioprostheses. Previous studies have shown that cellular surface seeding decreases calcium uptake in vitro and in vivo, but complete coverage remains difficult to achieve. A new approach is presented, masking glutaraldehyde residues with a covalently bound polymer layer thus facilitating cell seeding. The aim of this study was to evaluate different polymers for their ability to promote surface cell adhesion and formation of complete monolayers. Ten ultrathin polymers, covalently bound to glass and exhibiting different physicochemical characteristics (thickness, molecular weight, hydrophilic properties, electrical charge) were seeded with human endothelial cells. Four of the ten polymers were also seeded with fibroblasts. As a reference, both cell types were seeded on glass surface. Quality of cell growth and coverage was evaluated by light and scanning electron microscopy. Five of ten polymers and glass exhibited excellent growth and complete surface coverage after 2 weeks, two allowed less cell adherence than glass reference, and three showed only poor cellular growth without adherence. Scanning electron microscopy demonstrated an intact monolayer for the five polymers with excellent cell coverage. Fibroblasts grew well on glass but not on the four tested polymers. No correlation was found between molecular weight, thickness, hydrophilic or charge characteristics of the polymers. Several ultrathin polymers, seeded with human endothelial cells, permit complete monolayer formation, but without any apparent correlation to physicochemical characteristics. Polymers covalently bound to biologic tissue appear as a promising approach to prevent calcific degeneration of bioprostheses.
ABSTRACT Bei 35 Patienten (mittleres Alter 64,0 Jahre (±10,4 Jahre) wurde bei fehlender oder unbr... more ABSTRACT Bei 35 Patienten (mittleres Alter 64,0 Jahre (±10,4 Jahre) wurde bei fehlender oder unbrauchbarer V. saphena magna neben der einoder beidseitigen A. thoracica interna (ITA) die rechte A. gastroepiploica (GEA) zur Revaskularisation der rechten Koronararterie (RCA) verwendet. Ausgeschlossen wurden Patienten mit erheblicher Adipositas (Broca-Index >20%) sowie Patienten mit abdominellen Voroperationen. In einem Fall konnte die GEA wegen Plaquebildung nicht verwendet werden. Bei 23 Patienten wurde die GEA mit dem R. interventricularis posterior (RIVP), bei 11 Patienten mit der RCA vor bzw. in Höhe der Crux anastomosiert. Von den 34 mit GEA versorgten Patienten verstarb einer (2,9%), bei dem die GEA mit einer dominanten RCA anatomososiert war, frühpostoperativ an therapierefraktärem Herzversagen. Bei diesem Patienten wurde die während der Reanimation von der Anastomose abgescherte GEA frei blutend in der Bauchhöhle gefunden. An weiteren Komplikationen trat bei einem Patienten ein konservativ beherrschbarer paralytischer Ileus auf. Eine Kontroll-DSA bei 24 Patienten zeigte bis auf einen funktionellen Verschluß eine freie Durchgängigkeit der GEA mit Darstellung der Anastomose. Die GEA bietet die Möglichkeit, den mit der rechten ITA nur eingeschränkt erreichbaren Teil der distalen RCA zu versorgen. Aufgrund des möglicherweise initial relativ geringen Flusses der GEA stellt eine stenosierte und dominante RCA primär dagegen eine Indikation zum Venenbypass dar. In 35 patients (mean age 64.0 years (±10.4 years) with an inadequate greater saphenous vein the right gastroepiploic artery (RGEA) was used together with the uni- or bilateral internal thoracic artery (ITA). Patients with extreme obesity (Broca-Index >20%) as well as patients with previous abdominal operations were excluded. In one case the GEA had to be discarded because of plaque formation. The GEA was anastomosed with the posterior descending artery in 23 patients and directly with the right coronary artery (RCA) in 11 patients. One patient (2.9%) in whom the GEA had been anastomosed with a dominant RCA died perioperatively because of refractory myocardial failure. During the reexploration the GEA was found sheared off within the abdominal cavity. One patient suffered from a paralytic ileus that was treated without operation. Digital intraarterial subtraction angiography revealed a patent GEA in 24 patients and one functionally occluded bypass in one. The right gastroepiploic artery offers the possibility to supply the distal part of the right coronary artery that is difficult to reach with the right ITA. In case of a stenotic and dominant RCA venous bypass should be preferred because of a possible initial low flow of the GEA.
The Annals of Thoracic Surgery, Apr 1, 2006
Background. Interaction of circulating leukocytes and vascular endothelium plays an important rol... more Background. Interaction of circulating leukocytes and vascular endothelium plays an important role in vasoconstriction, endothelial dysfunction, and vascular injury. Dilation procedures of grafts before coronary artery bypass graft surgery might lead to vascular injury and subsequent bypass graft disease.
Thorac Cardiovasc Surg, 1987
A case of a 23 year old female patient who suffered from the complex congenital heart lesion of a... more A case of a 23 year old female patient who suffered from the complex congenital heart lesion of a double inlet left ventricular main chamber, subaortic small left sided right ventricle and interrupted aortic arch type A is reported. With equally high blood pressures, the perfusion in the upper half of the body was maintained through the ascending aorta while the lower half and the lungs were supplied through the pulmonary artery and a patent ductus arteriosus (PDA). Angiographically, the bulbo-ventricular foramen appeared to be nonrestrictive. However, distinct signs of muscular subaortic stenosis were detected. The hemodynamic status principally allowed surgical correction when this became necessary because of increasing left heart failure. Treatment for this complex lesion undoubtedly required reduction of pulmonary perfusion, even when associated with the danger of increasing cyanosis. Various forms of surgical treatment (functional correction, palliative procedures) were discussed. The most elegant was performed without cardiopulmonary bypass: this consisted in connection of the pulmonary artery with the descending aorta using a 16 mm Dacron tube, reconstruction of the aortic arch by a prostheso-subclavian synthetic graft, suture ligation of the PDA, and banding of the pulmonary artery trunk distal to the origin of the prosthesis. One year after the operation, the patient's physical performance has improved. Moreover, despite the disappearance of cardiac failure she has not become more cyanotic during exertion.
The Annals of Thoracic Surgery, Nov 1, 2009
Deut Med Wochenschr, 1988
Langenbecks Arch Surg, 1987
The Journal of Thoracic and Cardiovascular Surgery, Nov 1, 2002
Cardioprotective effects of the serine protease inhibitor aprotinin after regional Objective: Ear... more Cardioprotective effects of the serine protease inhibitor aprotinin after regional Objective: Early coronary reperfusion of the ischemic myocardium is a desired therapeutic goal to preserve myocardium. However, reperfusion itself contributes to an additional myocardial injury (ie, reperfusion injury), which has been attributed to neutrophil infiltration with subsequent release of proteases and oxygen-derived radicals. We studied the effects of the serine protease inhibitor aprotinin (Trasylol) on myocardial ischemia and reperfusion in a rat model.
The Journal of Heart Valve Disease, Nov 1, 2006
BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the efficacy of three different... more BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the efficacy of three different anticoagulants in preventing thrombus formation on mechanical heart valves, using an in-vitro system.METHODS: Blood samples (470 ml) were taken from young and healthy male volunteers and anticoagulated with unfractionated heparin (UFH; n=18), low molecular-weight heparin (LMWH; n=18) or fondaparinux (n=16). Bileaflet mechanical heart valves were placed in a new device--the 'Thrombosis Tester'--and exposed in a continuous circulation at a rate of 80 beats per min to the anticoagulated blood samples for a total exposure time of 60 min. Results for thrombus weight were skewed distributed and presented as log-transformed values.RESULTS: The weight of each valve was measured before and after 1 h of perfusion; subsequent mean (+/-SD) thrombus weights were 0.739 +/- 0.573 g for UFH, 0.789 +/- 0.099 g for LMWH, and 0.934 +/- 0.145 g for fondaparinux (p = 0.397 for comparison of all groups by ANOVA). Electron microscopy showed concordant results with regard to thrombus formation on heart valve surfaces.CONCLUSION: Fondaparinux and LMWH were as effective as UFH in preventing thrombus formation on mechanical heart valves in vitro. The 'Thrombosis Tester' proved to be a new, unique instrument for investigating the ability of anticoagulants to prevent valve thrombosis on mechanical heart valves under in-vitro conditions.
Journal of Pharmacology and Experimental Therapeutics, Jul 1, 1998
Myocardial injury after ischemia (I) and reperfusion (R) is related to leukocyte activation with ... more Myocardial injury after ischemia (I) and reperfusion (R) is related to leukocyte activation with subsequent release of cytokines and oxygen-derived free radicals as well as complement activation. In our study, the cardioprotective effects of exogenous C1 esterase inhibitor (C1 INH) were examined in a rat model of myocardial I ϩ R (i.e., 20 min ϩ 24 hr or 48 hr). The C1 INH (10, 50 and 100 U/kg) administered 2 min before reperfusion significantly attenuated myocardial injury after 24 hr of R compared to vehicle treated rats (P Ͻ .001). Further, cardiac myeloperoxidase activity (i.e., a marker of PMN [polymorphonuclear leukocyte] accumulation) in the ischemic area was significantly reduced after C1 INH treatment compared to vehicle treated animals (0.81 Ϯ 0.1, 0.34 Ϯ 0.13, 0.13 Ϯ 0.1 vs.
Herz, 2004
Hintergrund und Ziel: Kalzifikation und Degeneration stellen die Hauptprobleme im Langzeitverlauf... more Hintergrund und Ziel: Kalzifikation und Degeneration stellen die Hauptprobleme im Langzeitverlauf nach Implantation biologischer Prothesen dar. In Vorläuferstudien konnte gezeigt werden, dass sich durch eine Bedeckung der Oberfläche des Biomaterials mit Zellen eine Reduktion der Calciumaufnahme erzielen lässt. Allerdings ist eine vollständige Oberflächenbesiedelung schwer zu erreichen. Daher wurde das Konzept der kovalenten Bindung von Polymeren an die Oberfläche des Implantats und der sich daran anschließenden Zellbesiedelung entwickelt. Ziel der aktuellen Studie war die Austestung verschiedener Polymere auf ihre Fähigkeit, die Adhärenz humaner Zellen zu fördern, so dass sich ein intakter Monolayer ausbildet. Material und Methodik: Zehn an Glas gebundene ultradünne Polymere mit unterschiedlichen physikochemischen Eigenschaften wurden mit humanen Endothelzellen und vier von diesen zehn Polymeren mit Fibroblasten besiedelt. Das Wachstumsverhalten wurde mit dem der Zellen auf einer Glasoberfläche verglichen. Das Wachstum wurde photographisch im Phasenkontrastmikroskop und in der Elektronenmikroskopie dokumentiert.
Herz, 2004
Background and Purpose: Cardiac troponins have shown to be specific markers of myocardial injury.... more Background and Purpose: Cardiac troponins have shown to be specific markers of myocardial injury. The aim of this prospective study was to compare patterns and kinetics of troponin I and T after coronary artery bypass grafting (CABG) with or without perioperative myocardial infarction (PMI). Patients and Methods: 119 patients (male/female: 96/23, age 64 ± 10 years) underwent first time elective
Bio Medical Materials and Engineering, Feb 1, 2004
Reoperation of aldehyde tanned bioprotheses due to calcific degeneration remains their major draw... more Reoperation of aldehyde tanned bioprotheses due to calcific degeneration remains their major drawback. Based on experiments studying mechanisms and factors that influence the time phase, extent and progression of calcification and evaluating the efficiency of anticalcification treatments and the effects of surface seeding with vital cells a new concept to avoid calcification emerged: masking aldehyde-residues with a covalently bound polymer that supports surface cell seeding. Different covalently bound polymers were tested for their suitability to grow cells. Dense cell growth was achieved on some polymers but without correlation to physico-chemical properties. Ultrathin coating of biological materials appears a promising approach to achieve lining with vital cells.
Thorac Cardiovasc Surg, 1987
In a total of 30 operations the mitral valve was reconstructed in 18, the tricuspid valve in 11, ... more In a total of 30 operations the mitral valve was reconstructed in 18, the tricuspid valve in 11, and both AV-valves in one patient. The result of reconstruction was tested first in the open arrested heart by injection of crystalloid solution into the appropriate ventricle either through the reconstructed valve or one of the great arteries. Upon termination of cardiopulmonary bypass the valve function was examined in the beating heart by means of transesophageal contrast echocardiography (TEE). For visualization 0.5-1.0 cc of agitated Gelifundol was injected into the ventricle. In 22 patients open testing as well as echocardiographic visualization showed identical and good operative results. In 6 patients TEE revealed mild insufficiency, but no further surgery was done. In three patients with mitral valve repair, contrast-echocardiography showed severe insufficiency, which had not been detected during cardiac arrest. In these patients changes in the level of the subvalvular apparatus caused systolic dislocation of the leaflets and massive reflux. Because of these findings definive valve replacement was performed in the same operation. Intraoperative TEE is a simple, safe and reliable method für assessment of AV-valve repair, thereby motivating the surgeon towards valve preservation and improving the outcome of valve surgery.
The American Journal of Surgical Pathology, Mar 1, 2010
Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypi... more Follicular dendritic cell (FDC) sarcoma is a very rare neoplasm showing morphologic and phenotypic features of FDCs. It occurs primarily in lymph nodes but also in extranodal sites. So far, there have been no reports on FDC sarcoma associated with myasthenia gravis. In the following we will present a case of an FDC tumor of the mediastinum associated with paraneoplastic myasthenia gravis in a 39-year-old man. The tumor contained a major proportion of immature T cells, which may be connected to this patient's very unusual clinical presentation with autoimmune phenomena. Extranodal FDC sarcomas still seem hardly noticed, and their clinical and pathologic characteristics remain to be better defined.
Langenbecks Arch Surg, 1987
In 17 patients (10 patients with mitral insufficiency, 5 patients with tricuspid regurgitation, 2... more In 17 patients (10 patients with mitral insufficiency, 5 patients with tricuspid regurgitation, 2 patients with mitral stenosis) the result of valve reconstruction was evaluated by intraoperative two-dimensional transesophageal contrast-echocardiography (TEE). Therefore, 1-2cc of an agitated contrast-medium (Gelifundol) were injected into the left or right ventricle. The result of reconstruction was assessed by the extent of regurgitant microbubbles into the left or right atrium. A successful valve repair could be demonstrated in 15 patients without or with only minimal regurgitation of contrast-fluid. In one patient residual severe mitral insufficiency after valve reconstruction could only be detected when valve function was examined by contrast-TEE in the beating heart. An intraoperative decision for valve replacement was made. In another patient, mild to moderate residual mitral incompetence was shown; no further surgical intervention was done. By TEE the function of reconstructed valves can be examined under physiological conditions in the beating heart. Surgeons can obtain additional intra-operatively information and certainty about the result of reconstruction and an early decision for valve replacement can be made if necessary.
Thorac Cardiovasc Surg, 2010
Herz, Jun 1, 2004
Calcific degeneration with the resulting need for operative replacement remains the major drawbac... more Calcific degeneration with the resulting need for operative replacement remains the major drawback of bioprostheses. Previous studies have shown that cellular surface seeding decreases calcium uptake in vitro and in vivo, but complete coverage remains difficult to achieve. A new approach is presented, masking glutaraldehyde residues with a covalently bound polymer layer thus facilitating cell seeding. The aim of this study was to evaluate different polymers for their ability to promote surface cell adhesion and formation of complete monolayers. Ten ultrathin polymers, covalently bound to glass and exhibiting different physicochemical characteristics (thickness, molecular weight, hydrophilic properties, electrical charge) were seeded with human endothelial cells. Four of the ten polymers were also seeded with fibroblasts. As a reference, both cell types were seeded on glass surface. Quality of cell growth and coverage was evaluated by light and scanning electron microscopy. Five of ten polymers and glass exhibited excellent growth and complete surface coverage after 2 weeks, two allowed less cell adherence than glass reference, and three showed only poor cellular growth without adherence. Scanning electron microscopy demonstrated an intact monolayer for the five polymers with excellent cell coverage. Fibroblasts grew well on glass but not on the four tested polymers. No correlation was found between molecular weight, thickness, hydrophilic or charge characteristics of the polymers. Several ultrathin polymers, seeded with human endothelial cells, permit complete monolayer formation, but without any apparent correlation to physicochemical characteristics. Polymers covalently bound to biologic tissue appear as a promising approach to prevent calcific degeneration of bioprostheses.
ABSTRACT Bei 35 Patienten (mittleres Alter 64,0 Jahre (±10,4 Jahre) wurde bei fehlender oder unbr... more ABSTRACT Bei 35 Patienten (mittleres Alter 64,0 Jahre (±10,4 Jahre) wurde bei fehlender oder unbrauchbarer V. saphena magna neben der einoder beidseitigen A. thoracica interna (ITA) die rechte A. gastroepiploica (GEA) zur Revaskularisation der rechten Koronararterie (RCA) verwendet. Ausgeschlossen wurden Patienten mit erheblicher Adipositas (Broca-Index >20%) sowie Patienten mit abdominellen Voroperationen. In einem Fall konnte die GEA wegen Plaquebildung nicht verwendet werden. Bei 23 Patienten wurde die GEA mit dem R. interventricularis posterior (RIVP), bei 11 Patienten mit der RCA vor bzw. in Höhe der Crux anastomosiert. Von den 34 mit GEA versorgten Patienten verstarb einer (2,9%), bei dem die GEA mit einer dominanten RCA anatomososiert war, frühpostoperativ an therapierefraktärem Herzversagen. Bei diesem Patienten wurde die während der Reanimation von der Anastomose abgescherte GEA frei blutend in der Bauchhöhle gefunden. An weiteren Komplikationen trat bei einem Patienten ein konservativ beherrschbarer paralytischer Ileus auf. Eine Kontroll-DSA bei 24 Patienten zeigte bis auf einen funktionellen Verschluß eine freie Durchgängigkeit der GEA mit Darstellung der Anastomose. Die GEA bietet die Möglichkeit, den mit der rechten ITA nur eingeschränkt erreichbaren Teil der distalen RCA zu versorgen. Aufgrund des möglicherweise initial relativ geringen Flusses der GEA stellt eine stenosierte und dominante RCA primär dagegen eine Indikation zum Venenbypass dar. In 35 patients (mean age 64.0 years (±10.4 years) with an inadequate greater saphenous vein the right gastroepiploic artery (RGEA) was used together with the uni- or bilateral internal thoracic artery (ITA). Patients with extreme obesity (Broca-Index >20%) as well as patients with previous abdominal operations were excluded. In one case the GEA had to be discarded because of plaque formation. The GEA was anastomosed with the posterior descending artery in 23 patients and directly with the right coronary artery (RCA) in 11 patients. One patient (2.9%) in whom the GEA had been anastomosed with a dominant RCA died perioperatively because of refractory myocardial failure. During the reexploration the GEA was found sheared off within the abdominal cavity. One patient suffered from a paralytic ileus that was treated without operation. Digital intraarterial subtraction angiography revealed a patent GEA in 24 patients and one functionally occluded bypass in one. The right gastroepiploic artery offers the possibility to supply the distal part of the right coronary artery that is difficult to reach with the right ITA. In case of a stenotic and dominant RCA venous bypass should be preferred because of a possible initial low flow of the GEA.
The Annals of Thoracic Surgery, Apr 1, 2006
Background. Interaction of circulating leukocytes and vascular endothelium plays an important rol... more Background. Interaction of circulating leukocytes and vascular endothelium plays an important role in vasoconstriction, endothelial dysfunction, and vascular injury. Dilation procedures of grafts before coronary artery bypass graft surgery might lead to vascular injury and subsequent bypass graft disease.
Thorac Cardiovasc Surg, 1987
A case of a 23 year old female patient who suffered from the complex congenital heart lesion of a... more A case of a 23 year old female patient who suffered from the complex congenital heart lesion of a double inlet left ventricular main chamber, subaortic small left sided right ventricle and interrupted aortic arch type A is reported. With equally high blood pressures, the perfusion in the upper half of the body was maintained through the ascending aorta while the lower half and the lungs were supplied through the pulmonary artery and a patent ductus arteriosus (PDA). Angiographically, the bulbo-ventricular foramen appeared to be nonrestrictive. However, distinct signs of muscular subaortic stenosis were detected. The hemodynamic status principally allowed surgical correction when this became necessary because of increasing left heart failure. Treatment for this complex lesion undoubtedly required reduction of pulmonary perfusion, even when associated with the danger of increasing cyanosis. Various forms of surgical treatment (functional correction, palliative procedures) were discussed. The most elegant was performed without cardiopulmonary bypass: this consisted in connection of the pulmonary artery with the descending aorta using a 16 mm Dacron tube, reconstruction of the aortic arch by a prostheso-subclavian synthetic graft, suture ligation of the PDA, and banding of the pulmonary artery trunk distal to the origin of the prosthesis. One year after the operation, the patient's physical performance has improved. Moreover, despite the disappearance of cardiac failure she has not become more cyanotic during exertion.
The Annals of Thoracic Surgery, Nov 1, 2009
Deut Med Wochenschr, 1988
Langenbecks Arch Surg, 1987