The Clinical Research Of Embolization Of Intracranial Aneurysms With Nexus^TM Coil

BackgroudIntracranial aneurysm is the buble-like processes caused by abnormal changes in blood vessels.The rupture of intracranial aneurysms is one of the major causes of cerebral hemorrhage,accounting for more than 70%of subarachnoid hemorrhage.And it will cause the high mortality rates and disability.1%-2%of unruptured aneurysms will rupture each year in the future.And the ruptured aneurysms have higher rates of rebleeding,there are 2 major methods to treatment intracranial aneurysms:the traditional craniotomy and clipping and endovascular embolization treatment.In recent years,Endovascular coil embolization using bare platimum coil has become an accepted therapeutic option for the treatment of intracranial aneurysms.The most important limitation of coil embolization is the possibility of aneurysm recanalization,which results in aneurysm recurrence. Platinum coils are biologically inert and produce a limited and delayed inflammatory response.To overcome this limitation,various modified coils have been developed and are commercially available,for example,hydrogel-coated coil(Hydrocoil).The Nexus^TM Coil is a new type of modified coil,and is made of platimum coil and fiber which is made of PGLA.Nexus^TM Coil is an embolic agent that may improves packing attenuation because it is soft,and the fiber can promote thrombosis and machines,and can prevent early thrombosis dissolved and these Features might reduce the rate of aneurysm recurrence.Nexus^TM Coil received the US Food and Drug Adminidtration in 2005.Our hospital has initially used Nexus^TM Coil to treat aneurysms from 2008. ObjectiveTo study the clinical effectiveness and safety of endovascular aneurysm occlusion with Nexus^TM coil,compare complete obliteration rate,volume embolization ratio,recanalization,rebleed,complication and Modified Rankin scale between hydrocoil and bare platinum coil.MethodsA retrospective analysis was conducted of a total of 97 patients with Bare platinum coils and Nexus^TM coil,who had full clinical data in Zhujiang hospital from 2007 to 2008.Among them,there were 12 patients lost,12.37%.The inclusion criteria were as follows:1) ruptured or unruptured intracranial aneurysm,2) Age＜80, maximal aneurysmal diameter≥2 mm,3) The Bare platinum include Microplex, Orbit,NXT,GDC 10,GDC 18 or Nexus^TM coil(EV3).The exclusion criteria included: 1) complex-shaped(or severely multilobulated) aneurysms,fusiform,infectious, traumatic or dissecting aneurysms;2) Multiple Aneurysms;3) Patients undergoing arterial occlusion with coils.4).Giant aneurysms,maximal aneurysmal diameter＞25 mm;5).flaiembolization with other coated coils;6).stent-assisted coil embolization, remoding or other assisitive technology;7) recanalizion aneurysms.In all patients with full clinical date,85 patients have followed up over 6 months.The patients have divide into Nexus^TM coil group of 42 patients and Bare platinum coil of 43 patients to compare complete obliteration rate,volume embolization ratio,recanalization, rebleed,complication and Modified Rankin scale between hydrocoil and bare platinum coil.Statistical analysis was performed using Statistical Package for Social Sciences(SPSS 13.0).And the following Statistical analysis were used,Bare platinum coils were analyzed usingχ² tests,Independent-Samples T test,two-way ANOVA and Wilcoxon's rank sum test.P＜0.05 was considered significant.Results1.Aneurysm complete obliteration rate after endvosculation.Complete obliteration rate were better in NexusTM Coil(88.1%) than Bare platinum Coil(74.4%),but there were no statistically significantly different. Complete obliteration rate of NexusTM Coil group in small,medium,large aneurysm were 100%,88.5%,66.7%,respectively,that better than Bare platinue group in small, medium,large aneurysm were 94.1%,65.2%,33.3%,respectively.2.volume embolization ratio(VOA)Volume embolization ratio for Nexus^TM Coil 40.02±13.21%was significantly (F=5.878,P=0.018) greater than Bare platinum coil 32.87±14.20%(F=5.878, P=0.018).Volume embolization ratio for Nexus^TM Coil group in small,medium,large aneurysm were 51.08±8.73%,37.38±10.18%,15.00±1.00%,respectively.Volume embolization ratio for Bare platinue group in small,medium,large aneurysm were 42.38±9.84%,29.00±12.20%,8.67±1.46%,respectively.We can see that the VOA for Nexus^TM Coil was greater than Bare platinum coil.The VOA for earch group in small, medium,large aneurysm have statistically significantly different,too.(F =15.069,149.221 respectively,P=0.000,0.000 respectively)and according to the aneurysms become larger and larger,the volume embolization ratio becomes more and more lower.3.Aneurysm recanalizationAneurysm recanalization rate for Bare platinum coil(20.9%) was significantly (P=0.039))greater than Nexus^TM Coil(7.1%) withχ² test(χ²=4.25).Among 13 patients of Aneurysm recanalization,11 case(84.2%) of VOA lower 25%,2 case (15.4%) of VOA over 25%.5 case(38.5%) have complete obliteration after procedure,and 8 case(61.5%) have no complete obliteration.4.RebleedingOne pantient have rebleeding in the group of Nexus^TM Coil,threre in the group of Bare platinum.The rebleed rate is 2.4%,7.0%respectively.5.ComplicationThe complication for Nexus^TM Coil and Bare platinum coil is 19.0%,16.3% respectively.Procedural complications rate of Nexus^TM Coil group and Bare platinum coils group were 11.9%and 4.7%respectively and the long-term complication were 7.1%,11.6%respectively. 6.Survial free of disability at 6 months(Modified Rankin scale) There were no significantly difference between the two treatment groups(81.0%and 79.1%for endovascular with Nexus^TM and Bare platinum coils respectively.Conclusion1.Endovascular aneurysm occlusion with Nexus^TM Coil is effective and safity.2.Aneurysm recanalization associated with volume embolization ratio. Improvement of volume embolization ratio could reduce aneurysm recanalization rate.3.Endovascular aneurysm occlusion with Nexus^TM Coil improve complete obliteration rate and reduce recanalization rate.4.Endovascular aneurysm occlusion with Nexus^TM Coil have batter rate of Survial free of disability at 6 months,low complication(Procedural complications and long-term complication).5.The PGLA fiber banded to Nexus^TM Coil may be associated with lower relapse rates,and is still necessary to further study.6.Durability of aneurysm occlusion with Nexus^TM in the long-term is still unknown and necessary to follow up.