Coils, intracranial aneurysm

New England Journal of Medicine 336 28-40 Schwartz TH, Solomon RA (1996). Perimesencephalic nonaneurysmal subarachnoid hemorrhage review of the literature. Neurosurgery 39 433-440 Sluzewski M, van Rooij WJ, Beute GN et al. (2005). Late rebleeding of ruptured intracranial aneurysms treated with detachable coils. American Journal of Neuroradiology 26 2542-2549 Smith ER, Carter BS, Ogilvy CS (2002). 

In a study by Fanning et al. (2007) 100 intracranial aneurysms were embolized with HydroCoils in conjunction with bare platinum coils, where a basket of bare platinum coils were positioned in the aneurysm, followed by the introduction of HydroCoils. The treatment group showed a 20% increase in the mean packing density when the same number of coils was used in the control... 

Matrix detachable coils (Boston Scientific Neurovascular) are another example of modified endovascular coils, employing a stainless steel delivery wire coated with a bioabsorbable copolymer of 90% polyglycolide and 10% polylactide. In a study by Murayama et al. (2003), matrix detachable coils were shown to accelerate the rate of aneurysm healing in swine aneurysm models, specifically by promoting the formation of a thick neointimal layer at the aneurysm neck more quickly bare platinum coils (Murayama et al, 2003). Taschner et al. (2005) evaluated the use of Matrix detachable coils in 25 patients with intracranial aneurysms. Again, stable emboUzed aneurysms were achieved over a six-month period, but only when Matrix coils were used in conjunction with bare platinum coils (Taschner et al, 2005). 

International Subarachnoid Aneurysm Trial (ISAT) Collaborative Group. (2002) International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms a randomised trial. The Lancet, 360, 1267-1274. 

Kawanabe, Y., Sadato, A., Taki, W. Hashimoto, N. (2001) Endovascular occlusion of intracranial aneurysms with Gughelmi detachable coils correlation between coil packing density and coil compaction. Acta Neurochirurgica, 143, 451-455. 

Lanzino, G., Kanaan, Y., Perrini, P., Dayoub, H. Fraser, K. (2005) Emerging concepts in the treatment of intracranial aneurysms stents, coated coils, and liquid embolic agents. Neurosurgery, 57, 449-459. 

Taschner, C. A., Leclerc, X., Rachdi, H., Barros, A. M. Pruvo, J.-P. (2005) Matrix detachable coils for the endovascular treatment of intracranial aneurysms analysis of early angiographic and clinical outcomes. Stroke, 36, 2176-2180. 

Guglielmi G (1999) Treatment of an intracranial aneurysm using a new three-dimensional-shape Guglielmi detachable coil technical case report [comment]. Neurosurgery 45 959-961... 

Raymond J, Roy D, Leblanc P, et al. (2003) Endovascular treatment of intracranial aneurysms with radioactive coils initial clinical experience. Stroke 34 2801-2806... 

Malek AM, Halbach VV, Phatouros CC, et al. (2000) Balloon-assisted technique for endovascular coil embolization of geometrically difficult intracranial aneurysms. Neurosurgery 46 1397-1406... 

Embolic agents can cause permanent or temporary occlusion. According to their behavior in the bloodstream, embolic agents may be categorized as mechanically either proximally or distally occlusive and distally flow-dependent ocdusive. In case of a (pseudo-)aneurysm, endosaccular embolization might he an option, similar to coiling of intracranial aneurysms (Table 5.3). 

Future perspectives Detachable coils can be repositioned until a focal and compact mechanical obstruction is achieved. Detachable coils may be covered with small Dacron strands to promote thrombus formation or with an expanding hydrogel to minimize dead space between the coil loops. Although dedicated detachable coils are available for intracranial aneurysm embolization, the high cost of these coils precludes its routine use in non-neurointerventional indications. 

Shape memory PU has been proposed as a candidate for aneurysm coils [106]. An intracranial aneurysm can go undetected until the aneurysm ruptures, causing... 

SMP foams have been proposed as a treatment for intracranial aneurysms. An SMP foam would allow for the placement of a single compacted device that would gently expand to fill the entire aneurysm (Fig. 5). This would potentially reduce the complexity of multiple coil placement, avoid coil-induced rupture, decrease surgery time, and allow for a porous matrix for cell invasion and neointima formation to seal the neck of the aneurysm. 

The course of infectious aneurysms is unpredictable. Under antibiotic or antimycotic therapy they may shrink, or completely disappear. However, enlargement during treatment has also been reported (Brust et al. 1990). Septic aneurysms can be obliterated surgically or by endovascular treatment (Chapot et al. 2002 Phuong et al. 2002 Steinberg et al. 1992). The theoretical assumption that implantation of foreign material - like platinum coils - into an infectious lesion might worsen the problem is not true for infectious intracranial aneurysms. Mortality due to rupture of bacterial cerebral aneurysms is reported to be up to 60% (Barrow and Prats 1990 Bohmfalk et al. 1978 Clare and Barrow 1992). 

The high morbidity and mortality in patients with ruptured aneurysms prompted interest in repair of aneurysms that are diagnosed before they have ruptured. Following publication of the initial results of the International Study of Unruptured Intracranial Aneurysms (ISUIA 1998), enthusiasm for this strategy was markedly reduced. In this study patients were classified in those with no history and those with history of SAH. The risk posed by unruptured aneurysms was reported lower than had been previously expected and also morbidity and mortality to treat aneurysms were higher than had previously been reported. The updated results of the same group analysed 6544 patients years of prospective follow up of untreated aneurysms, 1692 had no treatment, 1917 had surgical repair and 451 had their unruptured aneurysm coiled. The cut off... 

ISAT was a randomised, prospective, international, controlled trial of endovascular coiling vs surgical clipping for a selected group of patients with ruptured intracranial aneurysms deemed suitable for both types of therapy. Most patients were treated at high-volume centres in the United Kingdom, with the remainders from other European countries, Australia, Canada, and the United States. The primary endpoint was patient outcome, defined as a modified Rankin scale of 3-6 (dependent or deceased) at 1 year. The primary hypothesis was that endovascular treatment would reduce the proportion of patients dependent or deceased by 25% at 1 year. A total of 9559 patients with SAH were screened... 

Abrahams JM, Diamond SL, Hurst RW, Zager EL, Grady MS (2000) Topic review surface modifications enhancing biological activity of Guglielmi detachable coils in treating intracranial aneurysms. Surg Neurol 54 34-40 discussion 40-41... 

Brilstra EH, Rinkel GJ, van der Graaf Y, van Rooij WJ, Al-gra A (1999) Treatment of intracranial aneurysms by embolization with coils a systematic review. Stroke... 

Flemming KD, Wiebers DO, Brown RD Jr, Link MJ, Huston J III, McClelland RL, Christianson TJ (2005) The natural history of radiographically defined vertebrobasilar nonsaccular intracranial aneurysms. Cerebrovasc Dis 20(4) 270-279. Epub 2005 Aug 22 Forsting M, Albert FK, Jansen O, von Kummer R, Aschoff A, Kunze S, Sartor K (1996) Coil placement after clipping endovascular treatment of incompletely clipped cerebral aneurysms. Report of two cases. J Neurosurg 85 966-969... 

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