BACKGROUND: The long-term outcome of endovascular coiling of cerebral aneurysms is directly related to the packing density at time of treatment. In general, the highest packing density achievable is only about 45% due to the quasi-random distribution of currently available coils within aneurysms. We investigated whether packing densities could be maximized via more ordered coil configurations. METHODS: Three different coil configurations - circular loops, planar spirals, and spherical helices - were investigated. The packing densities achievable in maximally filling the volume of an exemplar human basilar aneurysm with each coil configuration were calculated numerically. Coil packing simulations were also carried out for aneurysms idealized as spheres over diameters ranging from 2 to 30 mm. RESULTS: The packing densities with the loop, spiral, and spherical helix configurations were 82%, 60%, and 73%, respectively, for the human aneurysm model; the numbers of coils required were 693, 34, and 13, respectively. Simulations within idealized aneurysms suggest that aneurysms cannot be packed to more than 91% with coils of constant circular cross-section. The spherical helix configuration provides a constant packing density (coefficient of variation 0.4%) over the range of aneurysm diameters studied as compared to the two other configurations (coefficients of variation 9% and 8%). CONCLUSIONS: Coil configurations that allow for ordered filling of cerebral aneurysms can potentially provide packing densities that are twice those currently achieved. The spherical helix configuration seems to be the most technically feasible and stable configuration of the three coil types investigated.
BACKGROUND: The long-term outcome of endovascular coiling of cerebral aneurysms is directly related to the packing density at time of treatment. In general, the highest packing density achievable is only about 45% due to the quasi-random distribution of currently available coils within aneurysms. We investigated whether packing densities could be maximized via more ordered coil configurations. METHODS: Three different coil configurations - circular loops, planar spirals, and spherical helices - were investigated. The packing densities achievable in maximally filling the volume of an exemplar human basilar aneurysm with each coil configuration were calculated numerically. Coil packing simulations were also carried out for aneurysms idealized as spheres over diameters ranging from 2 to 30 mm. RESULTS: The packing densities with the loop, spiral, and spherical helix configurations were 82%, 60%, and 73%, respectively, for the humananeurysm model; the numbers of coils required were 693, 34, and 13, respectively. Simulations within idealized aneurysms suggest that aneurysms cannot be packed to more than 91% with coils of constant circular cross-section. The spherical helix configuration provides a constant packing density (coefficient of variation 0.4%) over the range of aneurysm diameters studied as compared to the two other configurations (coefficients of variation 9% and 8%). CONCLUSIONS:Coil configurations that allow for ordered filling of cerebral aneurysms can potentially provide packing densities that are twice those currently achieved. The spherical helix configuration seems to be the most technically feasible and stable configuration of the three coil types investigated.
Authors: Menno Sluzewski; Willem Jan van Rooij; Marian J Slob; Javier Oliván Bescós; Cornelis H Slump; Douwe Wijnalda Journal: Radiology Date: 2004-04-29 Impact factor: 11.105
Authors: Chander Sadasivan; Jeremy Brownstein; Bhumika Patel; Ronak Dholakia; Joseph Santore; Fawaz Al-Mufti; Enrique Puig; Audrey Rakian; Kenneth D Fernandez-Prada; Mohamed S Elhammady; Hamad Farhat; David J Fiorella; Henry H Woo; Mohammad A Aziz-Sultan; Baruch B Lieber Journal: Cardiovasc Eng Technol Date: 2013-03-01 Impact factor: 2.495