Thrombosis, propagating

Acute anticoagulation is widely used in the acute setting of arterial dissection. Once again, the rationale is to prevent propagation of local thrombosis and formation of new thrombus at the site of the injured arterial wall, which is beheved to reduce the likelihood of early stroke recurrence. This practice, while rational, is based on anecdotal evidence and case series, as randomized controlled trials have... 

The ideal anticoagulant drug would prevent pathologic thrombosis and limit reperfusion injury, yet allow a normal response to vascular injury and limit bleeding. Theoretically this could be accomplished by preservation of the TF-VIIa initiation phase of the clotting mechanism with attenuation of the secondary intrinsic pathway propagation phase of clot development. At this... 

Propagating thrombosis proximal or distal to a thrombotic, embolic or any other type of occlusion, or within collateral vessels, is often assumed to explain neurological deterioration if other causes have been excluded. However direct evidence is almost impossible to obtain, except perhaps with transcranial Doppler. 

In theory, recurrent embolization may cause deterioration. However, the distinction between propagating thrombosis and embolization is very difficult. There is only anecdotal evidence that full anticoagulation with intravenous heparin slows progression and improves outcome if no other cause of deterioration is evident (SUvka et al. 1989). 

Retardation of clotting is important in blood transfusions, to avoid thrombosis after surgery or from other causes, to prevent recurrent thrombosis in phlebitis and pulmonary embolism. and to lessen the propagation of clots in the coronary aitcries. This retardation may be accomplished by agents that inactivate thrombin (heparin) or substances that prevent the fotmation of prothrombin in the liver (the coumarin derivatives and the phenylindanedione derivatives). 

Catheter-related venous thrombosis occurs in 30%-70% of patients with long-term central venous catheters. Fortunately, the majority of patients are asymptomatic (Haire et al. 1991 Wechsler et al. 1993). Complete thrombosis of the parent vein will present as arm, neck, or face swelling. If the thrombus is isolated in the axillary or subclavian vein, ipsilateral arm swelling will occur. If the thrombus propagates... 

Thrombosis of AVF necessitates treatment as quickly as possible because delayed intervention allows the thrombus to propagate, and become fixed to the vein wall with a local inflammation, making any thrombectomy attempt difficult and predisposing to arterial wall damage with its risk of re-thrombosis. Thrombosed V A can be treated either by an open or endovascular intervention. Thrombectomy alone is generally insufficient unless the underlying stenotic lesion is corrected. 

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