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Anita Pritisanac

Publications and source records attributed to Anita Pritisanac.

8 recordsLinked to original sources
PubMed2006

Successful endothelialization of porcine glutaraldehyde-fixed aortic valves in a heterotopic sheep model.

PURPOSE: The purpose of our study was to evaluate the stability of an artificially seeded endothelial cell layer on porcine aortic prostheses under in vivo conditions in the arterial system. DESCRIPTION: Ten female sheep were divided into two groups. Animals of the study group (n = 7) had dissection of their right external jugular vein for cell harvesting. Myofibroblasts and endothelial cells were labelled with PKH-26, seeded onto pretreated (10% citric acid) porcine glutaraldehyde-fixed aortic valves (Freestyle, Medtronic Inc, Duesseldorf, Germany), and the valves were implanted into the descending aorta. Controls (n = 3) received pretreated but unseeded valves. A shunt between the aortic arch and the left atrial appendage ensured systolic or diastolic leaflet motions, or both, that were documented by sonography. After 3 months the valves were explanted. Specimens for scanning electron microscopy and immunohistochemical staining were taken prior to implantation and after explantation. EVALUATION: A neointimal proliferation was detected in the control group. No endothelial cells were found on the leaflets and the sinuses, but erythrocytes and thrombocytes were seen entrapped within the collagen fibers. Thrombus formation was documented macroscopically and histologically on the leaflets and the sinuses. In the study group a confluent endothelial cell layer was documented on the walls and leaflets. Neither neointimal proliferation nor any clots were seen. Some cells were still labelled positively indicating their origin from the initial cell seeding. No dilatation of any prosthesis was observed, but all valves showed slight thickening of the leaflets. CONCLUSIONS: The artificially seeded endothelial cell layers remained stable under in vivo conditions in the arterial system. Biocompatibility of the prostheses seemed to be improved by reduction of thrombogenicity.

Animals↗
PubMed2005

Seeding of human endothelial cells on valve containing aortic mini-roots: development of a seeding device and procedure.

PURPOSE: Complete covering of an artificial valvular scaffold with endothelial cells may prevent thromboembolic complications and lead to an excellent biocompatibility. For this purpose, we developed a seeding device for reproducible cell seeding on valve containing aortic roots. DESCRIPTION: Human endothelial cells and fibroblasts were obtained from saphenous vein pieces. Cryopreserved aortic roots (n = 25) were put into an especially developed tube, set on a rotator, and incubated with the cell suspension. The device rotated in two axes (sagittal and axial), ensuring slight movements of the leaflets. The rotation alternated with resting periods, allowing cell attachment to the surface. Different resting periods were tested (groups 1, 2, and 3 were 30, 45, and 60 min, respectively; n = 5 each). Total incubation time was 24 hours followed by further culturing for 6 days. In two further groups (groups 4 and 5; n = 5 each), a modified inlay was used to allow the cell suspension to flow around the entire graft. In group 4 the grafts were again incubated with human endothelial cells; however, in group 5 pre-seeding with autologous fibroblasts was done in addition. Immunohistochemical staining with antibodies against factor VIII, CD31, laminin, collagen IV, and CD90 were done, and scanning electron microscopy was done after initial seeding and after 6 days in culture. EVALUATION: Seeding resulted in homogenous cell layers on the luminal surface of the free walls in all groups. With resting periods of 45 minutes, these results were also obtained on the leaflets, whereas the other resting times resulted in defects of the endothelial cell layer on the cusps. After 6 days under culture conditions, the endothelial cell layers were confluent and viable, with the exception of the leaflets in group 1. With the modified inlay (groups 4 and 5), confluent cell layers were also achieved on the outer surface. In group 5 pre-seeding with autologous fibroblasts resulted in enhanced synthesis of extracellular matrix proteins, as was demonstrated with immunohistochemical staining for collagen IV and laminin. CONCLUSIONS: With this newly developed seeding device, confluent cell layers on valve containing aortic roots were reproducibly achieved. The technique enables further experimental research and even clinical application.

Aortic Valve↗
PubMed2005

An image of mitral valve repair.

Mitral regurgitation is a severe problem of the mitral valve mechanism caused by many factors, including ischemic and nonischemic cardiomyopathy, inflammation, degeneration and others. Regardless of the cause of valve dysfunction, many changes in surgical approach have been undertaken. The pioneering work of Carpentier led to the era of mitral valve reconstruction a few decades ago. Understanding the different techniques applied in several pathoanatomic settings is of major interest. This review summarizes the indications and results of this specific surgical procedure in the setting of ventricular dysfunction by different causes.

Cardiac Surgical Procedures↗
PubMed2004

Minimally invasive heart valve surgery: already established in clinical routine?

Cardiac valve replacement with the need for open heart surgery still has the highest morbidity and mortality rates among routine cardiac surgery, with the exception of aortic aneurysm repair and surgery for congenital heart defects. Reducing invasiveness is a desirable goal, and different strategies and approaches have been used to achieve this with valve repair or replacement less invasive. Despite the good results reported with minimally invasive techniques, time on extracorporal circulation is always longer compared with the conventional procedures. Since these techniques do not reduce real invasiveness but rather improve the cosmetic results, minimal-access surgery would be a better nomenclature. With the exception of patients at a high risk for sternal infections or redo heart operations, a reduction in postoperative morbidity by the avoidance of a median sternotomy is not yet definitely proven. Meanwhile, most surgeons comply with the demand for minimally invasive surgery posed by patients by reducing the length of the incision in aortic valve replacement and by using a right anterolateral approach with a limited incision for mitral valve operations. However, the use of endoscopic or robotic devices is limited to a few centers, and has not yet found its way into clinical routine. Nonetheless, minimally invasive or minimal-access surgery is now established in many centers, and patients should always be informed of these techniques. When this information is provided objectively and patient selection is carried out accurately, these alternative approaches can help to improve postoperative convalescence.

Adult↗
PubMed2002

Effects of phospholipid-coated extracorporeal circuits on clinical outcome parameters and systemic inflammatory response in coronary artery bypass graft patients.

INTRODUCTION: The use of extracorporeal circulation (ECC) during coronary artery bypass graft (CABG) surgery is associated with a systemic inflammatory response due to the contact of blood with artificial surfaces. The clinical relevance of ECC-related systemic inflammation varies with the patient, and such inflammation may be accompanied by intermittent organ dysfunction and an increased catecholamine requirement. We investigated the effects of a new phospholipid coating system of ECC on systemic inflammatory response and clinical outcome following CABG. METHODS: Patients scheduled for CABG surgery were prospectively divided randomly into 2 patient groups: patients using noncoated ECC materials and patients using phospholipid-coated ECC materials. Clinical data measured perioperatively included hemodynamics, aortic clamp time, duration of bypass, time to extubation, catecholamine requirement, length of intensive care unit (ICU) stay, postoperative blood loss, and amount of blood transfused. In addition, blood samples were collected before cannulation and at 2, 24, and 48 hours postoperative. Cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin 10 [IL-10]) and P-selectin were measured with an enzyme-linked immunosorbent assay. Plasma nitrate/nitrite levels (NOx) were determined by the Griess reaction. RESULTS: A significant increase of TNF-a level was noted in the uncoated control group only. In the uncoated group, IL-10 levels significantly increased at 2 hours postoperative, whereas levels remained unchanged in the phospholipid coating group. P-selectin increased 2 hours postoperative in the uncoated group, and no significant changes were noted in the phospholipid coating group. At 24 hours postoperative, total plasma NOx production significantly increased in the phospholipid coating group but remained constant in the control group. No significant differences with respect to postoperative parameters (time to extubation, ICU stay, amount of bleeding, blood transfused, and catecholamine requirement) were observed. CONCLUSIONS: Phospholipid coating significantly reduces the systemic increase in proinflammatory and anti-inflammatory cytokines and P-selectin. Despite the comparable clinical outcomes in this study, the observed significant reduction in systemic inflammatory parameter values suggests an improved biocompatibility of ECC materials when they are coated with phospholipids.

Aged↗