颅内外血管重建用于颅内复杂动脉瘤的治疗(附11例分析)

目的探讨应用颅内外血管重建技术治疗颅内复杂动脉瘤的技术要点。方法回顾性分析应用颅内外血管重建技术治疗11例颅内复杂动脉瘤的经验。行颈外动脉-大隐静脉-大脑中动脉搭桥手术5例,颈外动脉-桡动脉-大脑中动脉搭桥手术3例,颞浅动脉-大脑中动脉搭桥手术2例,枕动脉-小脑后下动脉搭桥手术1例。搭桥手术后行动脉瘤孤立术5例,载瘤动脉近心端阻断术6例。结果术后血管造影或3D-CTA显示吻合血管通畅9例,急性闭塞1例,慢性闭塞1例;动脉瘤不显影10例,动脉瘤接受对侧椎动脉供血而需行进一步介入栓塞治疗1例。术后随访6～67个月,平均40.6个月;1例移植血管慢性闭塞病人在术后第50个月死亡,余10例病人临床表现不同程度改善,未发生再出血。结论颅内外血管重建结合载瘤动脉近心端阻断或动脉瘤孤立术是治疗颅内复杂动脉瘤的有效方法。     

颅内-外血管搭桥加孤立术治疗大脑中动脉复杂动脉瘤

目的探讨颅内-外血管搭桥加动脉瘤孤立术在大脑中动脉复杂动脉瘤治疗中的方法和效果。方法对6例大脑中动脉复杂动脉瘤患者采用颅内-外血管搭桥加动脉瘤孤立手术。术后复查脑血管造影和(或)超声评价搭桥是否通畅,并就相关临床资料进行分析。结果颞浅动脉-大脑中动脉搭桥4例中,吻合口通畅4例,运动性语言障碍加重1例。颈外动脉-大隐静脉移植-大脑中动脉搭桥2例,搭桥血管不通畅1例。随访2-17个月,恢复良好5例,生活自理1例。结论颅内-外血管搭桥加动脉瘤孤立术是治疗大脑中动脉复杂动脉瘤的可行方法。     

血管搭桥治疗颅内复杂性动脉瘤(附39例报告)

目的 探讨应用血管搭桥治疗颅内复杂性动脉瘤的疗效.方法 39例颅内复杂性动脉瘤患者中11例患者有动脉瘤破裂,Hunt-Hess分级分别为I级和Ⅱ级.28例未破裂动脉瘤以头痛、脑神经压迫和脑缺血发病.用大隐静脉移植搭桥10例,桡动脉移植搭桥13例,颞浅动脉搭桥10例,枕动脉搭桥6例.搭桥动脉与接受动脉的血管吻合:大脑中动脉24例,小脑后下动脉5例,大脑后动脉P2段4例,大脑前动脉A2远端2例,椎动脉V5段2例,颈内动脉1例,小脑前下动脉1例.移植血管与供血动脉的吻合:颈外动脉19例,大脑中动脉8例,大脑前动脉A2段2例,椎动脉V3段2例,颈内动脉C2段1例,后交通动脉1例.另外6例枕动脉搭桥,无近心端血管吻合.在搭桥血管完毕后,将动脉瘤近心端和远心端的供血动脉结扎或夹闭,行动脉瘤孤立术.对19例有压迫脑神经或颅内占位的高颅压的患者,将动脉瘤切除.结果 35例术后恢复良好,3例出院后需要照顾,1例术后9 d死于脑干梗死.35例术后脑血管造影检查,34例移植搭桥血管畅通,动脉瘤消失;1例吻合血管未通,但无神经功能缺失表现.结论 血管搭桥可作为治疗难治性颅内复杂动脉瘤的有效方法 .     

血管移植搭桥治疗巨大动脉瘤

目的探讨中、高流量血管搭桥方法对颅内巨大颅内动脉瘤的治疗。方法8例巨大和颅底复杂动脉瘤患者,主要表现头痛发病者5例,视力减退者2例,面部麻木者1例。未破裂动脉瘤6例,2例患者发生动脉瘤破裂,Hunt-Hess分级分别为Ⅰ级和Ⅱ级。血管造影证实：动脉瘤体位于颈内动脉海绵窦段（C4段）4例、床突上段（C1段）2例、大脑中动脉M2～M1段者2例动脉瘤大小为2．5～6．0cm,平均直径3．7cm。其中6例动脉瘤为梭形,2例为宽颈动脉瘤。8例患者均采用额颞开颅,骨瓣要尽可能低到颅底,以缩短搭桥移植血管在颅外走行长度。通常用7-0显微缝线吻合移植血管与颈外动脉,用8-0缝线吻合移植血管与颅内段颈内动脉和大脑中动脉。4例患者利用大隐静脉移植搭桥,4例患者利用桡动脉移植搭桥。颅内、外搭桥完毕后将动脉瘤近心端和远端的供血动脉结扎和夹闭,阻断动脉瘤的全部血供。对3例有压迫脑神经或颅内占位引起颅压高的患者,将动脉瘤切除。结果5例术后头痛消失,1例视力减退者明显改善,1例动眼神经麻痹恢复。5例术后行脑血管造影检查,3例行CT血管造影检查,7例搭桥吻合血管全部畅通,动脉瘤消失。2例术后出现暂时性一侧肢体力弱,肌力在Ⅱ～Ⅲ级之间,术后1个月完全恢复。结论中、高流量颅内外血管搭桥可作为治疗颅内巨大动脉瘤的有效方法。     

颅内复杂动脉瘤搭桥孤立术疗效观察

目的 探讨颅内外血管吻合或搭桥联合动脉瘤孤立术治疗颅内巨大型复杂动脉瘤的术式选择及适应证.方法 回顾分析2008年2月-201 1年12月经脑血管造影术明确诊断的12例颅内巨大型动脉瘤患者术前评价方法 及手术治疗经过.结果 12例患者中颈内动脉系统巨大型动脉瘤6例(4例位于颈内动脉海绵窦段或床突段、2例位于颈内动脉交通段),大脑中动脉巨大型动脉瘤3例,后循环动脉瘤3例.其中7例术前MR灌注成像显示载瘤动脉远端组织存在明显缺血.选择行颞浅动脉.大脑中动脉低流量血管吻合术;5例载瘤动脉远端组织供血正常,且搭桥血管长度较长(≥15 cm)、术前球囊闭塞试验呈阴性、患侧压颈脑血管造影侧支循环充盈不良患者,行高流量颅内外血管搭桥术.11例术后神经功能缺损程度评价良好,改良Rankin量表评分0-3分;1例术后4分,3个月后改善至3分.结论 对于无法施行塑形夹闭术的颅内复杂巨大型动脉瘤患者,颅内外血管吻合或搭桥联合动脉瘤孤立术是其可选择的最后方法 ;而MR或CT灌注成像观察载瘤动脉远端组织供血正常与否.是选择不同流量血管吻合或搭桥术的关键.枕动脉、颞浅动脉或桡动脉为常用搭桥血管.     

颌内动脉搭桥治疗颅内巨大动脉瘤

目的 探讨颌内动脉与颅内动脉搭桥治疗复杂性动脉瘤的方法.方法 22例颅内巨大动脉瘤患者,颈内海绵窦段8例,大脑中动脉6例,眼动脉段4例,床突上段1例,椎-基底动脉交接处2例,基底动脉下段1例.瘤体有重要穿通动脉发出9例.3例经弹簧圈治疗后,动脉瘤复发.取7 cm桡动脉做移植血管,先行颌内动脉与桡动脉端-端吻合.颈内动脉瘤做桡动脉与中动脉M2起始部端-侧吻合,椎基底动脉瘤做大脑后动脉P2段近端行端-侧吻合.动脉搭桥后,16例海绵窦段和床突上段动脉瘤做孤立术,6例动脉瘤有穿动脉发出,仅作动脉瘤近端阻断远端开放,使搭桥血流逆流入动脉瘤体内,保持穿通动脉血流.结果 20例术后恢复良好,移植搭桥血管畅通,动脉瘤消失.2例吻合血管未通,但无缺血性神经功能缺失表现.22例患者经3个月-3.3年随访,21例恢复正常生活,1例因患其他疾病需要照顾.结论 用桡动脉移植,颌内动脉作为供血动脉与颅内动脉搭桥,可得到较高的搭桥通畅率和较小的损伤效果.     

颅内蛇形动脉瘤的外科治疗（附21例报告）

目的 探讨蛇形动脉瘤的手术治疗方法。方法 21例蛇形动脉瘤中,14例未破裂动脉瘤,主要症状为头痛4例、可逆性脑缺血发作3例、颈项强直和后组脑神经压迫5例、视野缺损1例、癫痫发作1例;有动脉瘤破裂的7例中,Hunt - Hess Ⅰ级和Ⅱ级6例、Ⅲ级1例。病程从20d至3.5年,平均7.3个月。动脉瘤位于大脑中动脉M1段6例,M2段近端4例;大脑前动脉A1段1例,A.2段近端1例;大脑后动脉P1段2例;基底动脉主干2例,椎动脉5例。动脉瘤直径0.3 ～2.5 em,平均1.2 cm。13例动脉瘤长3.0 cm以上,8例动脉瘤长5.O cm以上。桡动脉移植搭桥7例,颞浅动脉搭桥6例,枕动脉搭桥6例,大隐静脉移植搭桥2例。12例为颅内外动脉搭桥,供血动脉为颈外动脉5例,枕动脉4例,颌内动脉3例。接受动脉为大脑中动脉5例,小脑后下动脉3例,大脑后动脉P2段3例,小脑前下动脉1例。9例为动脉瘤近端与远端间的血管间插入移植搭桥,包括大脑中动脉M1与M2段间的插入移植搭桥3例,M1段间的搭桥2例,大脑前动脉A1远端与A2近端插入搭桥2例,椎动脉颅内与颅外端间搭桥2例。在搭桥外血管完毕后,11例行动脉瘤孤立术;7例行动脉瘤切除;3例仅将动脉瘤近心端阻断,保护穿通动脉开通,避免缺血发生。结果 20例术后恢复良好,包括头痛缓解,癫痫局部发作或大发作消失,肢体活动障碍的改善和视力的恢复。1例出院时需要照顾。术后脑血管造影检查,19例移植搭桥血管畅通,动脉瘤消失;1例吻合血管未通,但无神经功能缺失表现;1例颅内外搭桥后,术后第2天手术部位出现血肿,手术清除血肿,术后肢体肌力Ⅳ级。结论 对于单纯手术无法夹闭的蛇形动脉瘤,通过适当血管搭桥或插入性移植的方法可得到满意的效果。     

颞浅动脉-大脑中动脉搭桥联合血管内栓塞治疗前循环巨大蛇形动脉瘤

目的应用颞浅动脉-大脑中动脉搭桥联合血管内动脉瘤旷置或孤立术治疗3例前循环巨大蛇形动脉瘤,评估安全性及有效性。方法 2例颈内动脉巨大蛇形动脉瘤,1例大脑中动脉上干巨大蛇形动脉瘤。复合手术室内先行全脑血管造影,准确选择供血动脉、受体血管,体表定位骨窗后开颅行颞浅动脉-大脑中动脉搭桥,造影证实血管通畅后,行血管内动脉瘤旷置或孤立术。术后3个月行磁共振随访,术后6个月行DSA或MRA随访。结果术中造影提示血管吻合均通畅,2例颈内动脉蛇形动脉瘤行ICA球囊闭塞旷置动脉瘤,其中1例术中夹闭动脉瘤流出道行孤立术,术中造影提示动脉瘤少量显影并造影剂明显滞留。1例大脑中动脉上干蛇形动脉瘤行弹簧圈栓塞腔内闭塞术孤立动脉瘤,术中造影提示动脉瘤完全不显影。术后MRI检查提示3例动脉瘤均血栓形成,1例出现分水岭梗塞,治疗后遗留轻度面瘫。出院时GOS评分5分2例,4分1例。术后6个月复查DSA或MRA,动脉瘤无复发,载瘤动脉及吻合血管通畅,3例患者GOS评分均5分。结论复合手术内颞浅动脉-大脑中动脉搭桥联合血管内动脉瘤旷置或孤立术治疗前循环巨大蛇形动脉瘤可提高治疗精确性,创伤小,安全、有效。     

"双保险"颅内外血管搭桥术在巨大颈内动脉海绵窦段动脉瘤术中的应用

目的 探讨巨大颈内动脉海绵窦段动脉瘤治疗中,"双保险"颅内外血管搭桥术的适应证、手术技巧和疗效.方法 对5例巨大颈内动脉海绵窦段动脉瘤采用"双保险"颅内外血管搭桥(颞浅动脉-大脑中动脉;颈外动脉-桡动脉-大脑中动脉)、颈内动脉阻断术治疗,分析其治疗效果.结果 术后血管造影显示,4例吻合血管通畅,1例颞浅动脉-大脑中动脉吻合口狭窄.5例动脉瘤均不显影.随访3-24个月,临床症状均有好转,无动脉瘤复发或破裂.结论 "双保险"颅内外血管搭桥能有效防治术中、术后脑缺血,提高手术安全性,是治疗巨大颈内动脉海绵窦段动脉瘤有效、安全的方法.     

颅内外血管搭桥术治疗颅内巨大型动脉瘤

目的 报告采用动脉瘤夹闭联合颅内外血管搭桥术治疗6例颅内巨大型动脉瘤患者的临床经过,探讨手术适应证及治疗效果.方法 回顾分析6例颅内巨大型动脉瘤患者颅内外血管搭桥术前血流动力学状态、搭桥方式,以及临床和影像学转归.结果 6例患者中3例施行动脉瘤夹闭、切除(或载瘤动脉重建)联合颞浅动脉.大脑中动脉搭桥术,3例行动脉瘤夹闭、切除(或孤立)联合高流量搭桥术(颈外动脉.桡动脉,大隐静脉.大脑中动脉搭桥术).手术后平均随访17个月,近远期脑血管造影和CT血管造影检查显示,搭桥血管及吻合口血流通畅;临床症状与体征得到不同程度改善,随访期间无急性出血性或缺血性脑血管事件发生.3例行联合低流量搭桥术患者远期改良Rankin量表评分2例0分、1例2分;3例联合高流量搭桥术患者远期改良Rankin量表评分1例0分、2例1分.结论 对于脑血管重建术可能牺牲载瘤动脉或远端大脑中动脉血流的颅内复杂动脉瘤患者,可根据具体情况联合各种颅内外血管搭桥术使血流得到有效代偿.脑血管造影联合CT灌注成像对颅内巨大型动脉瘤远端组织灌注状态及侧支循环评价具有一定参考价值.     

大脑中动脉瘤的显微外科治疗

报告34例大脑中动脉瘤显微外科手术的经验,其中1例有2个动脉瘤,共计35个动脉瘤.本组中大型和巨型动脉瘤14个(40%).除2个大脑中动脉主干梭形动脉瘤行动脉瘤包囊,2个巨型动脉瘤行M_1阻断伴颅内外动脉吻合外,其余(88%)均做动脉瘤颈夹闭或动脉瘤切除.无手术死亡,2例术后发生神经功能缺失.平均随访6年,优良率达93.8%.对手术入路、手术方法加以讨论.     

Giant fusiform aneurysm with dissection in the middle cerebral artery: a case report]

A rare case of a giant fusiform aneurysm with dissection in the middle cerebral artery is reported. A 37-year-old man was referred to our hospital for severe headache and left retrobulbar pain. MRI and angiography showed a giant aneurysm in the temporal branch(M 2) of the left middle cerebral artery. We supposed that dissection had occurred from a giant fusiform aneurysm in the middle cerebral artery judging from presentation, MRI findings, angiography findings, and operative findings. Giant fusiform aneurysms in the middle cerebral artery(MCA) are uncommon cerebral aneurysms. The surgical approach or endovascular treatment to giant fusiform aneurysms in the MCA is technically difficult, so some patients are treated conservativery. However they have a poor natural history that differs from that of typical saccular aneurysms. And they have character of weakness in the internal elastic lamina, and therefore have the potential to dissect. We suggest that appropriate therapy including conservative therapy and surgical techniques is necessary for giant fusiform aneurysms even if they are found incidentally.     

Traumatic cerebral aneurysm formation following ventriculoperitoneal shunt insertion

Introduction Iatrogenic intracranial aneurysms are rare in children.Case report A 15-year-old girl presented in coma with a fixed dilated left pupil six weeks following removal of a long-standing left-sided ventriculoperitoneal shunt. Computed tomography (CT) and cerebral angiography revealed a left temporoparietal intracerebral haemorrhage with a fusiform distal middle cerebral artery aneurysm. The patient underwent image-guided localisation of the aneurysm to enable evacuation of the haemorrhage and resection of the fusiform aneurysm.Conclusion A high index of suspicion is required for diagnosis and early treatment to prevent unnecessary morbidity and mortality.     

血管内支架结合弹簧圈栓塞椎基底动脉梭形动脉瘤

目的 探讨和总结应用血管内支架结合弹簧圈栓塞颅内梭形动脉瘤的技术。方法 回顾性分析11例颅内梭形动脉瘤，均采用血管内支架结合弹簧圈技术治疗。结果 基底动脉处4例，椎动脉远端7例，11例全部应用支架结合弹簧圈栓塞。1例术后出现一过性脑缺血的表现。7例造影随访3－12个月，无复发及狭窄。结论 在栓塞颅内梭形动脉瘤时应用血管内支架结合弹簧圈技术，防止弹簧圈突入载瘤动脉，保持载瘤动脉通畅，提高了颅内梭形动脉瘤的疗效。     

自膨式支架结合弹簧圈栓塞椎基底系动脉瘤

目的 探讨和总结应用Neuroform自膨式支架结合弹簧圈栓塞颅内椎基底系动脉瘤的技术。方法 回顾性分析12例颅内椎基底系动脉瘤，均采用Neuroform自膨式支架结合弹簧圈技术治疗。结果 基底动脉3例，椎动脉远端9例，12例全部应用Neuroform自膨式支架结合弹簧圈栓塞。1例术后出现眩晕的表现。5例随访3个月，无复发、无狭窄及再出血。结论 在栓塞颅内动脉瘤时应用Neuroform自膨式支架结合弹簧圈技术，可防止弹簧圈突入载瘤动脉，保持载瘤动脉通畅，提高了颅内动脉瘤的疗效。     

大脑中动脉动脉瘤的显微手术治疗

目的总结显微外科手术处理大脑中动脉动脉瘤的经验。方法1998年1月～2006年1月共手术治疗大脑中动脉动脉瘤36例，男19例，女17例。年龄12～65岁（平均41岁）。36例共计38个大脑中动脉动脉瘤，动脉瘤大小3～60mm，其中3～7mm9个，8～14mm17个，15～24mm7个，≥25mm5个。术前破裂出血30例，其中14例形成脑内血肿；6例因其它疾病或体检时偶然发现。所有病例经DSA检查，部分病人同时行MRA或CTA检查，其中2例病人DSA检查未发现动脉瘤，而CTA则清楚显示动脉瘤。4例病人合并有其它部位动脉瘤，2例为双侧镜影动脉瘤。动脉瘤位于大脑中动脉分叉部30个，分叉部近端7个、远端1个。采用翼点入路，显微镜下打开侧裂，依动脉瘤部位，逆行或顺行沿大脑中动脉主干（支）寻找分离动脉瘤，并夹闭之。结果全部38个动脉瘤均用一个或多个动脉瘤夹夹闭，其中8个大或巨大动脉瘤同时摘除血栓并切除大部瘤体以解除其占位效应。术后恢复良好28例，发生偏瘫失语7例（因局部脑梗塞所致），死亡1例。结论显微手术治疗大脑中动脉动脉瘤可以获得满意疗效，术中应尽量避免损伤大脑中动脉的分支，防止术后发生脑梗塞造成患者神经功能障碍。     

3D-CTA对破裂大脑中动脉瘤诊断及手术指导意义

目的探讨3D-CTA对破裂大脑中动脉瘤诊断和手术指导作用。方法我院神经外科从2010年1月-2011年12月经3D-CTA对收住自发性蛛网膜下腔出血病人检查证实的122例颅内动脉瘤,其中18例为大脑中动脉动脉瘤,进行了术前CTA手术模拟。17例行翼点入路开颅显微外科手术,动脉瘤夹闭手术,与术前CTA影像学资料进行了对比。结果术前经3D-CTA诊断不同部位大脑中动脉瘤术中所见完全一致。术中除1例大脑中动脉瘤M2段梭形动脉瘤行包裹术外,其余17例动脉瘤均成功行夹闭手术。术后16例病人恢复良好痊愈出院。1例术前破裂大脑中动脉瘤病人,Hunt-Hess分级V级,术后双侧脑疝死亡。1例病人入院做术前准备时,动脉瘤二次破裂出血,急诊手术,术后病人偏瘫生活不能自理。结论术前单独依靠CTA对不同部位大脑中动脉瘤进行诊断及模拟手术,对破裂大脑中动脉瘤成功手术夹闭具有较好应用价值。     

Surgical strategies using cerebral revascularization in complex middle cerebral artery aneurysms

Objectives

To describe surgical strategies using cerebral revascularization for complex middle cerebral artery aneurysms unsuitable to microsurgical clipping.

Materials and methods

In this study, the clinical features, case management, and results in 9 consecutive patients who underwent 10 cerebral revascularization procedures between January 1999 and April 2008 were retrospectively analyzed. The patient population consisted of 6 men and 3 women whose ages ranged from 15 to 71 years (mean, 42.4 years). The size of the aneurysms ranged from 12 to 35 mm (mean, 24.3 mm). Treated aneurysms were located in the M1 segment in 2 patients, the middle cerebral artery (MCA) bifurcation in 3 patients, the distal M3 segment in 3 patients, and the anterior temporal artery (ATA; the early cortical branch of the M1 segment) in 1 patient. A total of 10 revascularizations were performed. Three aneurysms were saccular and six aneurysms were fusiform. For the fusiform aneurysms of the M1 segment in 2 patients, superficial temporal artery (STA) trunk–saphenous vein (SV)–MCA bypasses followed by trapping were performed. For the large saccular MCA bifurcation aneurysms in 3 patients, STA–MCA bypasses followed by complete neck clipping, including the revascularized branch with the preservation of the flow of the other branch, were performed in 2 cases, and a STA trunk–SV–MCA bypass secondary to direct neck clipping with the preservation of both M2 branches was performed in 1 case. For the fusiform distal MCA aneurysms, STA–MCA bypasses in 2 patients and in situ MCA–MCA bypasses in 2 patients were performed. In one case involving distal MCA fusiform aneurysm, STA–MCA bypass and MCA–MCA bypass were performed simultaneously. In a case involving fusiform ATA aneurysm, primary reanastomosis after aneurysm excision was performed in 1 patient.

Results

The post-operative 3-month Glasgow outcome scales were good recovery in 6 patients, severe disability in 1 patient, a vegetative state in 1 patient, and death in 1 patient. A follow-up angiography was performed in 6 patients and revealed a patent bypass in 5 patients. In one case treated by direct neck clipping secondary to cerebral revascularization, the angiography obtained 2 weeks later showed graft occlusion, but there were no neurologic symptoms. Among the unfavorable outcomes of 3 patients who did not undergo follow-up angiography, surgery-related morbidity secondary to cerebral infarction was due to the size discrepancy between the donor and recipient vessels in 1 patient with severe disability. In the other 2 patients, the preoperative conditions were Hunt and Hess grade V.

Conclusions

Cerebral revascularization is a safe and effective technique of treatment for selective cases of complex large or giant aneurysms and unclippable fusiform aneurysms in the MCA.     

Intracranial Fusiform Aneurysms: It's Pathogenesis, Clinical Characteristics and Managements

Objective

The objective of this study is to investigate clinical characteristics, management methods and possible causes of intracranial fusiform aneurysm.

Methods

Out of a series of 2,458 intracranial aneurysms treated surgically or endovascularly, 22 patients were identified who had discrete fusiform aneurysms. Clinical presentations, locations, treatment methods and possible causes of these aneurysms were analyzed.

Results

Ten patients of fusiform aneurysm were presented with hemorrhage, 5 patients with dizziness with/without headache, 4 with ischemic neurologic deficit, and 1 with 6th nerve palsy from mass effect of aneurysm. Two aneurysms were discovered incidentally. Seventeen aneurysms were located in the anterior circulation, other five in the posterior circulation. The most frequent site of fusiform aneurysm was a middle cerebral artery. The aneurysms were treated with clip, and/or wrapping in 7, resection with/without extracranial-intracranial (EC-IC) bypass in 6, proximal occlusion with coils with/without EC-IC bypass in 5, EC-IC bypass only in 1 and conservative treatment in 3 patient. We obtained good outcome in 20 out of 22 patients. The possible causes of fusiform aneurysms were regard as dissection in 16, atherosclerosis in 4 and collagen disease or uncertain in 2 cases.

Conclusion

There is a subset of cerebral aneurysms with discrete fusiform morphology. Although the dissection or injury of internal elastic lamina of the cerebral vessel is proposed as the underlying cause for most of fusiform aneurysm, more study about pathogenesis of these lesions is required.