Boerendonk, A. (2010) De initiele coagulerende werking van PU gemodificeerd met 55% PEG. thesis, Dentistry.
Full text available on request.Abstract
Background: Haemostatic agents widely used are gelatin and collagen. Their animal derived origin, may cause severe diseases like CJD or BSE. Polyurethane foam combined with Polyethylene Glycol (PEG), which is a fully synthetic and biodegradable haemostatic agent, will prevent this risk. It has been already tested in in vitro and in vivo studies to a certain extent. It has been proved that polyurethane foam enhances coagulation. The aim of this study is to discover the way this effect on the haemostasis is accomplished and especially how important the role of thrombocytes is in reaching coagulation. Patients and Methods: This in vitro study is divided into two parts. The first part is an experiment conducted with blood of 6 donors. Four samples were tested at the same time. The blood was divided into four cups. In one cup Polyurethane foam was added, in a different one collagen (Hemocollageme®) and in another cup gelatin (Spongostan®). The last cup was used as a control test, to which no material was added. Hereafter, the cups were placed in a coagulation machine for two minutes. After those two minutes the test materials were removed and a hemocytometric apparatus was used to count the free thrombocytes that were still present in the blood. The second part of this study was a test performed with human pool plasma, which is free of thrombocytes, bought at a blood bank (Sanquin, Groningen). Again, four samples were tested at the same time. In this part the pool plasma was divided into four cups. The same haemostatic materials were used as in the first part of this study; Polyurethane foam, Hemocollagene® and Spongostan®. The last cup was used as a control test. The samples were incubated for 15 minutes in the coagulation machine. After these 15 minutes, the test materials were removed and the cups were placed back into the coagulation machine. This machine measured the time to heamostasis of the pool plasma. Both parts of the study were also performed with Polyurethane foam with a different percentage of PEG. Results: A contact time of two minutes of Polyurethane foam and collagen with human whole blood led to a significantly lower amount of free thrombocytes compared to using no material. Both materials also showed a significantly faster coagulation of human pool plasma compared with the control group 'no material'. When both tests were done with Polyurethane foam with a different concentration of PEG, there were no significant differences found. Nevertheless, there seems to be an optimum for the best aggregation ofthrombocytes laying around 25% free PEG. In the coagulation machine Polyurethane foam with 0% free PEG initiated the best coagulation time. Conclusion: In contradiction to the literature, collagen in this study initiated a better coagulation and accomplished more aggregation of thrombocytes than gelatin. Polyurethane foam with 25% free PEG initiates a significantly higher amount of aggregation of thrombocytes in human whole blood and a significantly faster coagulation of pool plasma compared with using no test material. The working mechanism of the haemostatic capacity of Polyurethane foam is based on the cellular component as well as the intrinsic route of the molecular component of the coagulation cascade. This is probably initiated through the negatively loaded surface. Because of this working mechanism, polyurethane foam seems promising for use in patients who use thrombocyte aggregation inhibitor, as well as by patients who use coumarin derivatives.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Begeleiders: and Bos, Prof. Dr. R.R.M. and Broekema, Drs. F.I. and UMCG kaakchirurgie |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 11:07 |
| Last Modified: | 25 Jun 2020 11:07 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2678 |
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