Biomedical subjects
Publications and source records attributed to P Benedikt.
Patients with postinfarction ventricular septal rupture have poor residual or collateral blood flow in the infarct artery and do not benefit from ischemic preconditioning. This suggests that rupture of the ventricular septum occurs on an unprotected and unprepared myocardium.
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BACKGROUND: Postinfarction rupture of the left ventricle is a rare event in which approach is not clearly standardised and outcome after repair is unknown. Our experience with this pathology was reviewed to analyze methods of repair and assess outcome beyond the patient's hospitalisation. METHODS: Five patients underwent surgical repair of a postinfarction ventricular rupture between 1990 and 1998. Electromechanical dissociation (3 patients) and sudden hypotension and bradycardia (2 patients) were clinical indicators of rupture. Four patients underwent repair with cardiopulmonary bypass and 1 patient without. Repair consisted of epicardial patching (2 patients), direct suture (1 patient), infarct-exclusion (1 patient), and debridement and patch closure (1 patient) of the rupture. Myocardial revascularization was performed in 3 patients and mitral valve repair in 1 patient. RESULTS: A satisfactory hemodynamic state was restored and bleeding was controlled in all patients. Two patients died postoperatively and another patient died 4 months after hospital discharge as a result of cardiac failure and/or sepsis. The other 2 patients are alive and in excellent condition 6 and 30 months respectively after repair. CONCLUSIONS: Postinfarction rupture of the left ventricle bears a high mortality, but survival with an excellent quality of life is possible after surgical repair.
OBJECTIVE: In tissue engineering, three-dimensional biodegradable scaffolds are generally used as a basic structure for cell anchorage, cell proliferation and cell differentiation. The currently used biodegradable scaffolds in cardiovascular tissue engineering are potentially immunogenic, they show toxic degradation and inflammatory reactions. The aim of this study is to establish a new three-dimensional cell culture system within cells achieve uniform distribution and quick tissue development and with no toxic degradation or inflammatory reactions. METHODS: Human aortic tissue is harvested from the ascending aorta in the operation room and worked up to pure human myofibroblasts cultures. These human myofibroblasts cultures are suspended in fibrinogen solution and seeded into 6-well culture plates for cell development for 4 weeks and supplemented with different concentrations of aprotinin. Hydroxyproline assay and histological studies were performed to evaluate the tissue development in these fibrin gel structures. RESULTS: The light microscopy and the transmission electron microscopy studies for tissue development based on the three-dimensional fibrin gel structures showed homogenous cell growth and confluent collagen production. No toxic degradation or inflammatory reactions could be detected. Furthermore, fibrin gel myofibroblasts structures dissolved within 2 days in medium without aprotinin, but medium supplemented with higher concentration of aprotinin retained the three-dimensional structure and had a higher collagen content (P<0.005) and a better tissue development. CONCLUSIONS: A three-dimensional fibrin gel structure can serve as a useful scaffold for tissue engineering with controlled degradation, excellent seeding effects and good tissue development.
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The fish-mouth incision of the left ventricular apex is the established incision to access and close apical ventricular septum defect. A long diagonal branch may render this incision dangerous. In such a case, we performed a more anterior incision on the left ventricle, and fashioned a patch to exclude the whole defective area.
AIMS: The endovascular repair of abdominal aortic aneurysms (AAA) is a minimally invasive method which can be performed without laparotomy, thoracotomy or cross-clamping. Little is known about the endovascular feasibility in patients with contained ruptures. METHODS: Retrospective study on 31 patients (mean age 70 +/- 6 years, 27 men (87.1%) and 4 (12.9%) women), who were treated for a ruptured aortic aneurysm between January 1996 and July 1998. RESULTS: 17/31 (55%) patients were hemodynamically stable. 14 patients were in severe shock and two died preoperatively. The operative mortality (two just after entering the abdomen) was 17% (5/29 patients) due to irreversible shock. A graft repair was performed in 27 patients. Preoperative CT scan was available in 12/31 (39%) patients. An infrarenal neck was present in all patients (length: 19 +/- 9 mm, internal diameter: 23 +/- 5 mm). The internal diameter of the external iliac artery was 10 +/- 2 mm. Six patients has an additional aneurysm of the common iliac artery, none of them bilaterally. In one patient infrarenal kinking of more than 90 degrees was detected. CONCLUSIONS: In regard to the morphology, endovascular treatment would have been feasible in the majority of the patients where CT was already performed. Moreover, hemodynamic situation would have allowed to assess feasibility with a CT and perform endovascular treatment in most of patients with symptomatic or ruptured AAA. In conclusion, hemodynamically stable patients with symptomatic or leaking AAA should be investigated for endovascular repair.
Cell attachment to a scaffold is a precondition for the development of bioengineered valves and vascular substitutes. This attachment is generally facilitated by the use of precoating factors, but some can cause toxic or immunologic side effects. Autologous extracellular matrix (ECM) is used as a precoating factor in our study. Ascending aortic tissue was cultured to obtain human myofibroblasts. Autologous ECM was extracted from the same aortic tissue. Poly(glycolic acid) (PGA) scaffolds were precoated with autologous ECM, human serum, or poly-L-lysine; the control group was pretreated with phosphate buffered saline (PBS). Myofibroblasts were seeded onto each scaffold, and the cell attachment was assayed and compared. Compared with the control group, precoating with human serum, poly-L-lysine, and ECM increased number of attached cells by 24%, 53%, and 48%, respectively. Differences between precoating groups were significant (p < 0.01), except for ECM versus poly-L-lysine. Scanning electron microscopy also demonstrated the high degree of cell attachment to the PGA fibers on scaffolds precoated with ECM and poly-L-lysine. Precoating polymeric scaffold with autologous human extracellular matrix is a very effective method of improving cell attachment in cardiovascular tissue engineering without the potential risk of immunologic reactions.