Experimental Study On Effect Of Mechanical Grinding On Physical Properties And Biological Safety Of Aneuiysm Clip

Objective:Aneurysm clips are mature commercial medical devices and the original product has stable physical properties and biocompatibility.However,the small bone window of the keyhole approach limits the freedom of surgical operations,and sometimes the length of the aneurysm clip blade has to be adjusted by mechanical grinding in order to properly clamp the aneurysm neck.However,up to now,there have been few relevant reports on whether this mechanical grinding will affect the physical properties and biocompatibility of aneurysmal neck.Therefore,this study carried out in vitro and in vivo experiments to address the above issues,providing experimental basis for further clinical applications.Methods:Taking BBraun aneurysm clips as the research object,high-speed grinding was applied to shorten the length of the blade.The closing force of different parts of the blade was measured and compared with that of the original unpolished aneurysm clip.In the process of grinding,it was determined whether the aneurysm clip blade was opened and whether it was rinsed with normal saline to cool down.The changes of closing force in different parts of the blade under the above conditions were measured and compared.Taking New Zealand white rabbits as the research object,polished and unpolished aneurysm clip leaves were implanted intracranially.The degree of adhesion between the aforementioned leaves and the surrounding brain tissues was compared and H&E staining of the surrounding brain tissue were also compared.Cerebrospinal fluid(CSF)was extracted for mass spectrum analysis of metal components of the different aneurysm clips.Results:When the opening degree of different parts of the aneurysm clip blade is the same,the closer the blade is to the stalk,the greater the closing force is.The same pattern was also observed in the aneurysm clip after blade grinding,and there was no significant effect on the closing force of the blade.No matter whether the blade is continuously washed and cooled with normal saline,the effect on the closing force is greater after grinding in the opening state.Under the same condition of blade opening and closing,continuous washing with normal saline can reduce the influence of grinding process on blade closing force.After the aneurysm clip blade was implanted intracranially in experimental rabbits,the adhesion of the blade with the surrounding brain tissue is more obvious with time goes on.At the same time point,the blade adhesion after grinding is more obvious.After blade implantation,the content of titanium,aluminum and vanadium in the CSF increased,and the content of the blade increased more obviously after implantation and polishing.Conclusions:Mechanical grinding of aneurysm clip blade can increase the closing force of the effective clamping part,while low temperature closing grinding has the least effect on the closing force of the blade.The polished leaves promote the adhesion of the surrounding brain tissue,and increase the precipitation of titanium,aluminum,vanadium and other metals into the CSF.