Aneurysm occlusion devices

Endovascular coiling is preferred to surgical clipping for the treatment of intracranial aneurysms, which affect between 2% and 6% of the world population (Ahuja et al., 1993 Horowitz, Samson, Purdy, 1997). Hampikian et al. (2006) evaluated the feasibility of using a novel block copolymer polyurethane, CalomerT, to replace platinum in aneurysm coils. The thermomechanical and radiographic properties were tested for both SMP polyurethane and a composite made of SMP with 3% metal filler. The intracranial aneurysm helical coils made from the SMP composite were successfully deployed inside an aneurysm model with simulated fluid forces. The scientists at Lawrence Livermore National Laboratory also developed a laser-activated SMP foam device for aneurysm occlusion (Maitland et al., 2007). Their SMP was synthesized from HDI, HPED, and TEA, similar to that used in the clot removal device (Wilson et al., 2005). In their preliminary in vitro basilar aneurysm model study, the... 

The In-Time Retriever (Boston Scientific, Natick, MA) has four to six wire loops and tends to bow when opened but has no specific opening to capture the embolus. This device has been successfully used in a case of an MCA occlusion resistant to thrombolytics and balloon angioplasty, as well as in cases of basilar occlusion. The TriSpan (Boston Scientific, Natick, MA), a neck bridge device consisting of three nitinol loops originally designed to treat wide-necked aneurysms, has also been used to treat basilar occlusions. ... 

As long as there is no celiac, proper hepatic, or SMA origin occlusion, the GDA can be sacrificed. If the GDA is required to maintain perfusion of the liver or, if flow into the SMA is dependent upon the celiac, then direct coiling of GDA pseudoaneurysms is preferable. This can he accomplished with stent placement over the aneurysm neck and microcoil deposition through the interstices via a microcatheter. A small-caliher stent graft such as a Jostent could theoretically be used in this situation. However, use of this device is still not approved by the FDA. Appel et al. described the placement of a 26-mm stent graft for humanitarian treatment of a traumatic pseudoaneurysm of the SMA [34]. 

It is known that small-diameter coronary prostheses with diameters <6 mm are not effective, since the body s reaction to foreign material will cause an occlusion of the device in a very short time. More commonly, textile-based prostheses are used where diameters of more than 6 mm are to be replaced. The most common textile prosthesis is used for the abdominal aortic aneurysm (AAA), a bulge of the aorta close to the bifurcation into the two iliac arteries leading into the legs. AAA is caused by a dilatation of the weakened vessel wall and occurs most commonly in older men (>60 years old). The disease is normally symptom free, but may end in a rupture of the aorta which leads to death within minutes due to internal bleeding. It is estimated that worldwide 4.5 million people are living with an AAA, and in the USA about 15,000 people die every year from AAA rupture. 

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