Jonathan Hartman

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A prototype endovascular electromechanical clot-extraction device was fabricated using a combination of shape memory polymer and shape memory nickel-titanium alloy (nitinol). Five embolic vascular occlusions were created in 4 rabbits by injecting thermally coagulated blood through a 4F catheter in the common carotid artery. Angiography immediately after(More)
BACKGROUND AND PURPOSE Percutaneous vertebroplasty is an effective tool for the relief of pain caused by osteoporotic spine fractures. Our purpose is to evaluate this technique and its effectiveness in restoring the height of such fractures. METHODS Forty osteoporotic vertebral body fractures in 30 consecutive patients (24 female, six males; mean age, 70(More)
An electromechanical microactuator comprised of shape memory polymer (SMP) and shape memory nickel-titanium alloy (nitinol) was developed and used in an endovascular thrombectomy device prototype. The microactuator maintains a straight rod shape until an applied current induces electro-resistive (Joule) heating, causing the microactuator to transform into a(More)
The Guglielmi detachable coil, a platinum microcoil used in the endovascular treatment of intracranial aneurysms, was studied in vitro for its MR imaging artifacts, heat production, and ferromagnetism. In addition, imaging artifacts were studied in vivo in eight patients who had undergone therapeutic placement of these coils. These devices displayed a very(More)
Cerebral vasospasm remains a leading cause of death and disability in patients with ruptured cerebral aneurysms. The development of endovascular intervention in the past two decades has shown promising results in the treatment of vasospasm. Endovascular techniques that have been used in humans include intra-arterial infusion of vasorelaxants and direct(More)
We demonstrate a new concept for endovascular embolization of nonnecked fusiform aneurysms. A device prototype consisting of a stent augmented with expandable foam, both made from shape memory polymer, was fabricated and deployed in an in vitro model. Visual observation indicated that the foam achieved embolization of the aneurysm while the stent maintained(More)
Pituitary apoplexy is an uncommon condition typically caused by acute, hemorrhagic expansion of the pituitary gland in patients with an adenoma that undergoes infarction. Although various risk factors have been described, the vascular events leading to apoplexy are not well understood. Disruption of microvascular blood flow is a well-known cause of(More)
BACKGROUND Vascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either by balloon expansion or by self-expansion. A shape memory polymer (SMP) stent may enhance flexibility, compliance, and drug elution compared to its current metallic(More)
Shape memory polymer (SMP) foam possesses structural and mechanical characteristics that make them very promising as an alternative treatment for intracranial aneurysms. Our SMP foams have low densities, with porosities as high as 98.8%; favorable for catheter delivery and aneurysm filling, but unfavorable for attenuating X-rays. This lack of contrast(More)