| 1. |
- Björses, Katarina, et al.
(författare)
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In vitro and in vivo evaluation of chemically modified degradable starch microspheres for topical haemostasis
- 2011
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Ingår i: ACTA BIOMATERIALIA. - : Elsevier Science B.V. Amsterdam. - 1742-7061 .- 1878-7568. ; 7:6, s. 2558-2565
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Tidskriftsartikel (refereegranskat)abstract
- Degradable starch microspheres (DSMs) are starch chains cross-linked with epichlorhydrin, forming glycerol-ether links. DSMs have been used for many years for temporary vascular occlusion and drug delivery in treatment of malignancies. They are also approved and used for topical haemostasis by absorbing excess fluid from the blood and concentrating endogenous coagulation factors, thereby facilitating haemostasis. This mechanism of action is not sufficient for larger bleedings in current chemical formulations of DSMs, and modification of DSMs to trigger activation of platelets or coagulation would be required for use in such applications. Chemical modifications of DSMs with N-octenyl succinic anhydride, chloroacetic acid, acetic anhydride, diethylaminoethyl chloride and ellagic acid were performed and evaluated in vitro with thrombin generation and platelet adhesion tests, and in vivo using an experimental renal bleeding model in rat. DSMs modified to activate platelets in vitro were superior in haemostatic capacity in vivo. Further studies with non-toxic substances are warranted to confirm these results and develop the DSM as a more effective topical haemostatic agent.
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| 2. |
- Asciutto, Giuseppe, et al.
(författare)
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Long-term progression of contralateral carotid artery disease after endarterectomy: is there a need for Duplex surveillance?
- 2012
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Ingår i: International Angiology. - 1827-1839. ; 31:4, s. 361-367
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aim of this paper was to define the incidence of disease progression of the contralateral internal carotid artery (CICA) in patients undergoing carotid endarterectomy (CEA) and to identify factors influencing disease progression. METHODS: Patients from our primary catchment area that had undergone CEA between 2002 and 2005 were included. The study cohort was divided in four groups based on the preoperative stenosis grade (normal ICA <40%, N.=56; mild 40-60%, N.=41; moderate 61-80%, N.=12; severe 81-99%, N.=7). Patients initially planned or already submitted to contralateral CEA or with contralateral occlusion were excluded. RESULTS: One hundred and seventeen patients were analysed. Disease progression occurred in 13 (11%) patients after a mean of 47.6 months (SD 1.6 months). A moderate preoperative CICA stenosis was associated with disease progression (P=0.017). Late neurologic events referable to the CICA independently of progression occurred in 13 (11%) patients. There were 4 (30.7%) events in the 13 carotids with progression and only 9 (7%) in the 117 without progression (P=0.060). .Moderate and severe preoperative CICA stenosis and renal insufficiency were associated with postoperative ipsilateral neurological symptoms (P=0.001 and 0.009, respectively). CONCLUSION: Disease progression of the CICA after CEA is not uncommon. The preoperative degree of CICA stenosis is related to subsequent disease progression and to the occurrence of symptoms. More studies are needed to identify risk factors influencing the progression of ICA disease.
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| 4. |
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| 5. |
- Björses, Katarina
(författare)
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Experimental Aspects of Topical Haemostatic Agents
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Control of haemorrhage is vital in all operative settings. As complement to traditional surgical haemostatic techniques, a heterogeneous collection of absorbable substances with haemostatic capacity have been developed; topical haemostatic agents. The widespread variety of the products and the study-populations (clinical or experimental) make interpretation of previously performed studies difficult. The general aim of this thesis was to evaluate the haemostatic efficacy of four principally different basic substances in two separate experimental bleeding models. Two coagulation factors; bovine thrombin (bT) and recombinant FVIIa (rFVIIa) and two passive substances; gelatine and microporous polysaccharide hemospheres (MPH) were evaluated, separately and combined, in a randomized fashion. Heparinized rats were used in all studies. In Paper I a new arterial high flow bleeding model was used and in Paper II-IV a renal bleeding model. The animals were additionally platelet inhibited in Paper III. Neither pure coagulation factors nor MPH was better than gauze (negative control). Gelatine was effective in heparinized rats, when platelet inhibition was added complementary bT was required for rapid and durable haemostasis. Topical rFVIIa proved a weak haemostatic effect compared to the effect when administered IV (positive control). Degradable starch microspheres (DSM) are similar to MPH. In Paper IV chemical modifications of DSM were performed, evaluated in vitro (thrombin generation and platelet adhesion tests), and in vivo. DSM modified to activate platelets demonstrated best haemostatic effect. In conclusion; for sufficient haemostatic effect, a topical agent is required to: adhere rapidly to the bleeding source, activate platelets and also stimulate the coagulation.
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| 6. |
- Björses, Katarina, et al.
(författare)
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Kissingstents in the Aortic Bifurcation - a Valid Reconstruction for Aorto-iliac Occlusive Disease.
- 2008
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Ingår i: European journal of vascular and endovascular surgery. - : Elsevier BV. - 1532-2165 .- 1078-5884. ; Aug 7, s. 424-431
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate outcome and patency predicting factors of kissingstent treatment for aorto iliac occlusive disease (AIOD). METHODS: Patients treated with kissingstents for AOID between 1995 and 2004 at a tertiary referral center were identified through local databases. Chart review and preoperative images were used for TASC and Fontaine classification. Follow-up consisted of clinical exams, ABI and/or duplex. Patency rates were estimated by Kaplan-Meier analysis, and Cox multivariate regression was used to determine factors associated with patency. RESULTS: 173 consecutive patients (46% male, mean 64 years) were identified. TASC distribution was: A 15%, B 34%, C 10%, D 41%. Mean follow-up was 36 months (range: 1-144). 30-day mortality was 1% (2 patients), and 1-year survival was 91% (157 patients). 2 patients underwent late, open conversion and 13 patients suffered minor puncture site complications. Primary, assisted primary and secondary patency was: 97%, 99% and 100%, and 83%, 90% and 95% at twelve and 36 months respectively. There was no significant difference in patency between the TASC groups. Patency was significantly worse for patients in Fontaine class III. CONCLUSIONS: Aortoiliac kissing stents is a valid alternative to open repair for TASC A-D lesions. The procedure has low mortality and morbidity and good patency at 3 years.
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| 7. |
- Björses, Katarina, et al.
(författare)
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Topical Haemostatics in Renal Trauma-An Evaluation of Four Different Substances in an Experimental Setting
- 2009
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Ingår i: Journal of Trauma. - 0022-5282. ; 66:3, s. 602-611
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Damage control is valuable in hemodynamically unstable trauma patients. To improve the hemostasis of packing, topical hemostatic agents have been suggested. The effects of such agents are unclear in trauma situations. The purpose of this study was to investigate the hemostatic capacity, and the stability of the hemostatic clot, of four substances with different mode of action in an experimental traumatic bleeding model. METHODS: A standardized heminefrectomy was performed in 180 heparinized and normotensive Sprauge-Dawley rats. Four different substances were studied (separately and in combinations) in a randomized fashion: gelatin (sponge and matrix), bovine thrombin, freeze-dried recombinant factor VIIa (rFVIIa), and microporous polysaccharide hemospheres. Eight treatment groups (15 animals/group) were considered, primary endpoint was hemostasis within 20 minutes of observation. The effective treatment groups were evaluated in a second set in the same experimental model, but with a prolonged observation time after hemostasis (60 minutes) to control the stability of the clot. RESULTS: Those animals treated with gelatin in the comparative study, with and without thrombin or rFVIIa, obtained hemostasis. Thrombin and rFVIIa alone did not have any hemostatic capacity. Only 20% to 25% of the animals obtained hemostasis with microporous polysaccharide hemospheres alone or in combination with rFVIIa. In the prolonged observation study, gelatin alone and in combination with thrombin or rFVIIa was studied. On average, 34% (20%-54%) of the animals rebled with no significant difference between the treatment groups. CONCLUSIONS: Gelatin-containing products provided a fast hemostasis in this experimental model. One third of the animals rebled, regardless of whether thrombin or rFVIIa was added. Further studies are demanded to confirm these results clinically.
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| 9. |
- Bonati, Leo, et al.
(författare)
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Restenosis and risk of stroke after stenting or endarterectomy for symptomatic carotid stenosis in the International Carotid Stenting Study (ICSS): secondary analysis of a randomised trial
- 2018
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Ingår i: Lancet Neurology. - 1474-4465. ; 17:7, s. 587-596
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Tidskriftsartikel (refereegranskat)abstract
- Background: The risk of stroke associated with carotid artery restenosis after stenting or endarterectomy is unclear. We aimed to compare the long-term risk of restenosis after these treatments and to investigate if restenosis causes stroke in a secondary analysis of the International Carotid Stenting Study (ICSS). Methods: ICSS is a parallel-group randomised trial at 50 tertiary care centres in Europe, Australia, New Zealand, and Canada. Patients aged 40 years or older with symptomatic carotid stenosis measuring 50% or more were randomly assigned either stenting or endarterectomy in a 1:1 ratio. Randomisation was computer-generated and done centrally, with allocation by telephone or fax, stratified by centre, and with minimisation for sex, age, side of stenosis, and occlusion of the contralateral carotid artery. Patients were followed up both clinically and with carotid duplex ultrasound at baseline, 30 days after treatment, 6 months after randomisation, then annually for up to 10 years. We included patients whose assigned treatment was completed and who had at least one ultrasound examination after treatment. Restenosis was defined as any narrowing of the treated artery measuring 50% or more (at least moderate) or 70% or more (severe), or occlusion of the artery. The degree of restenosis based on ultrasound velocities and clinical outcome events were adjudicated centrally; assessors were masked to treatment assignment. Restenosis was analysed using interval-censored models and its association with later ipsilateral stroke using Cox regression. This trial is registered with the ISRCTN registry, number ISRCTN25337470. This report presents a secondary analysis, and follow-up is complete. Findings: Between May, 2001, and October, 2008, 1713 patients were enrolled and randomly allocated treatment (855 were assigned stenting and 858 endarterectomy), of whom 1530 individuals were followed up with ultrasound (737 assigned stenting and 793 endarterectomy) for a median of 4·0 years (IQR 2·3–5·0). At least moderate restenosis (≥50%) occurred in 274 patients after stenting (cumulative 5-year risk 40·7%) and in 217 after endarterectomy (29·6%; unadjusted hazard ratio [HR] 1·43, 95% CI 1·21–1·72; p<0·0001). Patients with at least moderate restenosis (≥50%) had a higher risk of ipsilateral stroke than did individuals without restenosis in the overall patient population (HR 3·18, 95% CI 1·52–6·67; p=0·002) and in the endarterectomy group alone (5·75, 1·80–18·33; p=0·003), but no significant increase in stroke risk after restenosis was recorded in the stenting group (2·03, 0·77–5·37; p=0·154; p=0·10 for interaction with treatment). No difference was noted in the risk of severe restenosis (≥70%) or subsequent stroke between the two treatment groups. Interpretation: At least moderate (≥50%) restenosis occurred more frequently after stenting than after endarterectomy and increased the risk for ipsilateral stroke in the overall population. Whether the restenosis-mediated risk of stroke differs between stenting and endarterectomy requires further research.
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