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The Greenfield Vena Cava Filter: Operative Technique

The Greenfield Vena Cava Filter: Operative Technique

Operative Technique Anatomic definition of a patients IVC is mandatory prior to filter placement, as the device has a finite maximal diameter. In addition to congenital abnormalities in the venous system, cavae with diameters greater than 28 mm (so-called “megacavae”) may be encountered. Indeed, the one report of significant proximal filter migration was due to…

The Greenfield Vena Cava Filter: Mobin-Uddin Filter

Figure 1. The Greenfield filter (metric measure).

Mobin-Uddin Filter In order to appreciate the development of the Greenfield filter, it is necessary to understand what has previously been available. The Mobin-Uddin filter was the first widely used transvenous device, having been introduced in the 1960s. It resembles an umbrella and consists of six stainless steel spokes radiating from a central hub. A…

The Greenfield Vena Cava Filter

The Greenfield Vena Cava Filter

Tnterruption of the inferior vena cava (IVC) has been used for several decades as a means of protecting patients with lower extremity deep venous thrombosis (DVT) from pulmonary embolism (PE). The long history of this approach has been marked, as expected, by an evolution of the techniques employed. It took some years before it became…

The Relationship Between Migraine and Right-to-Left Shunt: Pathophysiologic Hypothesis

Different pathophysiologic hypotheses have been proposed to explain these findings. Firstly, trigger substances might enter the systemic circulation through the right-to-left shunt instead of being trapped in the pulmonary capillaries. These trigger substances could induce cerebral vascular instability or increased excitability of the CNS and provoke migraine attacks. In individuals without a right-to-left shunt or…

The Relationship Between Migraine and Right-to-Left Shunt: Migraine Criteria

In contrast, Yankovsky and Kuritzky reported aggravation of migraine with aura into a daily pattern after closure of an ASD in a single patient. The latter was also suggested by Mortelmans et al, who found an aggravation of migraine with aura after percutaneous ASD closure with relatively larger Amplatzer ASD devices. However, the reason for…

The Relationship Between Migraine and Right-to-Left Shunt: Shunt Closure and Migraine

We and others> have described the changes in prevalence of migraine after percutaneous PFO closure. These data are summarized in Table 1. All studies, except for the study by Schw-erzmann et al, showed a significant reduction in the prevalence of migraine and migraine with aura after percutaneous PFO closure. The relative reduction in prevalence of…

The Relationship Between Migraine and Right-to-Left Shunt: Occurrence of Right-to-Left Shunt and Migraine

In patients with migraine, the prevalence of a right-to-left shunt seems to be higher when compared to the general population. Two investigational groups used transcranial Doppler ultrasound to determine right-to-left shunts in patients with migraine. A right-to-left shunt was found in 23% of the patients with migraine without aura. Forty-one to 48% of the patients…

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