Combined mechanical and chemical thrombolysis in an experimental animal model: Evaluation by angiography and angioscopy

Ritchie, James L.; Hansen, Daniel; Johnson, Christopher C.; Vracko, Rudolf; Auth, David C.

doi:10.1016/s0002-8703(05)80083-3

Cited by 9 publications

(2 citation statements)

References 20 publications

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“…Compared to PTCA, the thrombectomy catheter did not cause embolization, as seen in all cases with PTCA. In contrast, PTCA produced a higher patency rate of 50% In a previous investigation using streptokinase after PRT, incremental removal of thrombus by streptokinase could not be demonstrated [24]. In the current study, t-PA produced additional, incremental removal of thrombus in a manner consistent with clinical investigations showing a higher patency rate for t-PA than with streptokinase [25,26].…”

Section: Discussion Thrombolysissupporting

confidence: 82%

Thrombolysis by rotational thrombectomy followed by tissue plasminogen activator: Evaluation by angioscopy

Johnson

Dewhurst

Vracko

et al. 1991

Cathet. Cardiovasc. Diagn.

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Thrombus removal using percutaneous rotational thrombectomy (PRT), followed by tissue plasminogen activator (t-PA), was studied by contrast angiography and fiberoptic angioscopy in a canine femoral artery model of thrombosis. After thrombus induction and following each treatment, comparisons were made between angioscopy and angiography for the detection of thrombus and subintimal dissection. Angioscopic images were scored in a blinded fashion for lining, protruding, or occlusive thrombus (class 1,2, or 3) as well as estimated wall coverage by thrombus. Angiograms were studied for percent diameter stenosis and the presence of flaps. Following external forceps crush injury of 18 arteries, two hour occlusion, and injection of thrombin, mean angiographic stenosis was 66%, thrombus coverage by angioscopy was 81%, and mean angioscopy class was 2.5. Following PRT, stenosis decreased to 27% (p less than 0.008), thrombus coverage was reduced to 49% (p less than 0.02), and angioscopy class dropped to 2.0 (p less than 0.07). After t-PA treatment, these values were further reduced to 25% (p = NS), 26% (p less than 0.02), and 1.3 (p less than 0.008), respectively. In comparison to angiography, subintimal dissection (seen as flaps) and thrombus (lining, protruding, or occlusive) were present significantly more often by angioscopy (p less than 0.001). It is concluded that PRT results in significant thrombolysis, apparent by angiography and angioscopy. Follow-up t-PA can produce additional, incremental thrombolysis, apparent only by angioscopy. A beneficial role for t-PA following mechanical thrombolysis is suggested by this model. The superior sensitivity of angioscopy for detection of flaps and thrombus is underscored by this study.

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Section: Discussion Thrombolysissupporting

confidence: 82%

Thrombolysis by rotational thrombectomy followed by tissue plasminogen activator: Evaluation by angioscopy

Johnson

Dewhurst

Vracko

et al. 1991

Cathet. Cardiovasc. Diagn.

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“…Crush injury models have been used extensively for the evaluation of various parameters of arterial thrombosis by other groups and ourselves [9,13,. This model is an extension of the arterial crush model to a purely percutaneous model.…”

Section: Limitations Of Modelmentioning

confidence: 99%

Percutaneous rotational thrombectomy reduces acute reocclusion in an animal model of acute coronary thrombosis

Dewhurst

Bruneau

Titus

et al. 1993

Cathet. Cardiovasc. Diagn.

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This study was designed to compare acute reocclusion rates after treatment of acute coronary thrombosis with a percutaneous thrombectomy device or standard balloon angioplasty. Our group has previously reported on the rationale and development of a mechanical device for the treatment of intra-arterial thrombosis. This device removes fibrin from thrombus, allowing for dissolution of the cellular elements of the thrombus. Theoretically, thrombus removal (as opposed to displacement) might result in a lower rate of acute rethrombosis. The present study utilizes the device percutaneously in the coronary arteries of closed chest swine and compares recanalization and reocclusion rates with standard balloon angioplasty. Twenty-six animals with total thrombotic coronary occlusions were treated; 13 with each device. Reocclusion rates with the thrombectomy device were significantly reduced at 60 min and 120 min after recanalization (p < 0.02), and the mean time to reocclusion was prolonged by 45 min (p = 0.07). Technical problems included poor handling characteristics in early prototypes and stress fractures secondary to improper use. Changes in catheter design and operator protocols have largely eliminated these problems. We conclude that this study demonstrates the feasibility of percutaneous mechanical thrombectomy in the coronary arteries and that reocclusion rates after recanalization of thrombotic occlusions compare favorably to standard angioplasty.

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In vivo veritas: Thrombosis mechanisms in animal models

Napoli

Nigris

Pignalosa

et al. 2006

Scandinavian Journal of Clinical and Laboratory Investigation

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Experimental models have enhanced our understanding of atherothrombosis pathophysiology and have played a major role in the search for adequate therapeutic interventions. Various animal models have been developed to simulate thrombosis and to study in vivo parameters related to hemodynamics and rheology that lead to thrombogenesis. Although no model completely mimics the human condition, much can be learned from existing models about specific biologic processes in disease causation and therapeutic intervention. In general, large animals such as pigs and monkeys have been better suited to study atherosclerosis and arterial and venous thrombosis than smaller species such as rats, rabbits, and dogs. On the other hand, mouse models of arterial and venous thrombosis have attracted increasing interest over the past two decades, owing to direct availability of a growing number of genetically modified mice, improved technical feasibility, standardization of new models of local thrombosis, and low maintenance costs. To simulate rupture of an atherosclerotic plaque, models of arterial thrombosis often involve vascular injury, which can be achieved by several means. There is no animal model that is sufficiently tall, that can mimic the ability of humans to walk upright, and that possesses the calf muscle pump that plays an important role in human venous hemodynamics. A number of spontaneous or genetically engineered animals with overexpression or deletion of various elements in the coagulation, platelet, and fibrinolysis pathways are now available. These animal models can replicate important aspects of thrombosis in humans, and provide a valuable resource in the development of novel concepts of disease mechanisms in human patients.

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Combined mechanical and chemical thrombolysis in an experimental animal model: Evaluation by angiography and angioscopy

Cited by 9 publications

References 20 publications

Thrombolysis by rotational thrombectomy followed by tissue plasminogen activator: Evaluation by angioscopy

Thrombolysis by rotational thrombectomy followed by tissue plasminogen activator: Evaluation by angioscopy

Percutaneous rotational thrombectomy reduces acute reocclusion in an animal model of acute coronary thrombosis

In vivo veritas: Thrombosis mechanisms in animal models

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