Efficacy and current limitations of intravascular stents for intracranial internal carotid, vertebral, and basilar artery aneurysms.

OBJECT: Results of previous in vitro and in vivo experimental studies have suggested that placement of a porous stent within the parent artery across the aneurysm neck may hemodynamically uncouple the aneurysm from the parent vessel, leading to thrombosis of the aneurysm. For complex wide-necked aneurysms, a stent may also aid packing of the aneurysm with Guglielmi detachable coils (GDCs) by acting as a rigid scaffold that prevents coil herniation into the parent vessel. Recently, improved stent system delivery technology has allowed access to the tortuous vascular segments of the intracranial system. The authors report here on the use of intracranial stents to treat aneurysms involving different segments of the internal carotid artery (ICA), the vertebral artery (VA), and the basilar artery (BA). METHODS: Ten patients with intracranial aneurysms located at ICA segments (one petrous, two cavernous, and three paraclinoid aneurysms), the VA proximal to the posterior inferior cerebellar artery origin (one aneurysm), or the BA trunk (three aneurysms) were treated since January 1998. In eight patients, stent placement across the aneurysm neck was followed (immediately in four patients and at a separate procedure in the remaining four) by coil placement in the aneurysm, accomplished via a microcatheter through the stent mesh. In two patients, wide-necked aneurysms (one partially thrombosed BA trunk aneurysm and one paraclinoid segment aneurysm) were treated solely by stent placement; coil placement may follow later if necessary. No permanent periprocedural complications occurred and, at follow-up examination, no patient was found to have suffered symptoms referable to aneurysm growth or thromboembolic complications. Greater than 90% aneurysm occlusion was achieved in the eight patients treated by stent and coil placement as demonstrated on immediate postprocedural angiograms. Follow-up angiographic studies performed in six patients at least 3 months later (range 3-14 months) revealed only one incident of in-stent stenosis. In the four patients originally treated solely by stent placement, no evidence of aneurysm thrombosis was observed either immediately postprocedure or on follow-up angiographic studies performed 24 hours (two patients), 48 hours, and 3 months later, respectively. CONCLUSIONS: A new generation of flexible stents can be used to treat complex aneurysms in difficult-to-access areas such as the proximal intracranial segments of the ICA, the VA, or the BA trunk. The stent allows tight coil packing even in the presence of a wide-necked, irregularly shaped aneurysm and may provide an endoluminal matrix for endothelial growth. Although convincing experimental evidence suggests that stent placement across the aneurysm neck may by itself promote intraluminal thrombosis, the role of this phenomenon in clinical practice may be limited at present by the high porosity of currently available stents.     

Dissecting aneurysms of the vertebral artery: a management strategy

OBJECT: The authors present a retrospective analysis of their experience in the treatment of vertebral artery (VA) dissecting aneurysms and propose a management strategy for such aneurysms, with special emphasis on the most formidable VA dissecting aneurysms, which involve the origin of the posterior inferior cerebellar artery (PICA). METHODS: Since 1998, 18 patients with VA dissecting aneurysms, 11 of whom presented with subarachnoid hemorrhage (SAH), have been treated by endovascular surgery at the authors' institution. Obliteration of the entire segment of the dissected site with coils (internal trapping) was performed for aneurysms without involvement of the origin of the PICA (12 cases; among these the treatment-related morbidity rate was 16.7%). The treatment strategy applied to PICA-involved VA dissecting aneurysms presenting with SAH (three cases) included proximal occlusion of the parent artery followed by internal trapping of the aneurysm (one case), proximal occlusion of the parent artery followed by occipital artery (OA)-PICA bypass (one case), and two-staged internal trapping of the aneurysm involving double PICAs (one case). For PICA-involved VA dissecting aneurysms that were not associated with SAH at presentation (three cases), OA-PICA bypass was performed and followed by internal trapping of the aneurysm (two cases). In the remaining case in which a fetal-type posterior communicating artery was present, internal trapping was performed following successful balloon test occlusion (BTO). Overall, there was no sign of infarction in the PICA territory, despite complete occlusion of aneurysms involving the PICA. There was no recurrent bleeding or ischemic symptoms during the follow-up periods. The overall treatment-related morbidity rate for the VA dissecting aneurysms involving the PICA was 16.7%. CONCLUSIONS: Dissecting VA aneurysms that do not involve the PICA can be safely treated by internal trapping. For those lesions that do involve the PICA, a decision-making algorithm is advocated to maximize the efficacy of the treatment as well as to minimize the risks of treatment-related morbidity based on BTO.     

Endovascular surgery using stents for vertebral artery dissecting aneurysms and a review of the literature

The treatment of dissecting aneurysms of the vertebral artery (VA) involving the posterior inferior cerebellar artery (PICA) or presenting with hypoplasia of the contralateral VA is controversial. We describe our experience with 4 ruptured and 2 unruptured VA dissecting aneurysms and discuss the efficacy of endovascular surgery using stents. All patients were male; their mean age was 50.7 years. According to World Federation of Neurological Surgeons (WFNS) grading, 3 of the ruptured aneurysms were grade V, the other was grade I. All patients were successfully treated using stents; in 5 we also coil-embolized the aneurysmal lumen. One aneurysm was treated by the placement of 2 stents covering the dissection site; there was a danger of aneurysmal rupture during coil embolization. No technical complications were encountered although one patient suffered minor rebleeding 5 days post-treatment. Delayed vasospasm occurred in 4 cases. According to the Glasgow Outcome Scale (GOS), at 3 months after treatment 2 patients had made a good recovery, one was moderately disabled, one suffered severe disability, and 2 had died. One death each was due to acute myocardial and brain stem infarction. Endovascular surgery using stents may be a useful treatment in patients in poor condition who manifest dissecting VA aneurysms involving the PICA or hypoplasia of the contralateral VA, especially in the acute period after rupture.     

Endovascular coil trapping for ruptured vertebral artery dissecting aneurysms by using double microcatheters technique in the acute stage

Summary ?Background. In the treatment of vertebral artery (VA) dissecting aneurysms, only proximal occlusion of the VA does not necessarily prevent rerupture. We evaluated the efficacy of coil trapping for the ruptured VA dissecting aneurysms using the double microcatheters technique. Methods. We treated 11 patients who presented with subarachnoid haemorrhage (SAH) due to rupture of a VA dissecting aneurysm which did not involve the posterior inferior cerebellar artery at the site of dissection. All patients tolerated the balloon occlusion test. Within 3 days of the SAH, the dissection site was trapped with a Guglielmi detachable coil (GDC) using the double microcatheters technique. The proximal and distal sites of the dissecting aneurysm were embolized simultaneously. Findings. GDC trapping at the affected site was successful in all 11 patients. Radiographic findings showed complete occlusion of the dissection site and patency of the unaffected artery. Although one patient experienced transient dysphagia, there were no major complications. Interpretation. The double microcatheters technique is effective for coil trapping of ruptured VA dissecting aneurysms in selected patients. The risks posed by this simple technique are minimal, even in the acute stage. Published online May 26, 2003     

Multimodal treatment of ruptured dissecting aneurysms of the vertebral artery during the acute stage

OBJECT: The goal of this study was to implement an algorithm for and assess the multimodal (endovascular and microsurgical) treatment of patients with ruptured dissecting aneurysms of the vertebral artery (VA) during the acute stage. METHODS: During a 4-year period, the authors treated 19 ruptured dissecting aneurysms of the VA during the acute stage, within 3 days after the hemorrhage. Factors guiding management decisions were tolerance of the test occlusion and the site of the dissection. The algorithm takes into account these factors to select among treatment options, that is, trapping of the VA with Guglielmi Detachable Coils (GDCs); trapping of the VA and revascularization of the posterior inferior cerebellar artery (PICA); trapping of the VA and VA-posterior cerebral artery (PCA) anastomosis; and trapping of the VA, VA-PCA anastomosis, and revascularization of the PICA. Of the 15 aneurysms without PICA involvement, 14 were treated by trapping of the VA with GDCs and one by trapping of the VA and a VA-PCA bypass. The other four aneurysms with PICA involvement were treated by VA trapping and PICA revascularization. There was no episode of recurrent hemorrhage or ischemia during the posttreatment follow-up period. Although lateral medullary syndrome developed as a permanent complication in one patient, a good recovery was made by the other 18 patients by 6 months after the ictus. CONCLUSIONS: The factors that determine the appropriate treatment for ruptured dissecting aneurysms of the VA are tolerance of a test occlusion and the site of dissection. Favorable patient outcomes can be achieved when this algorithm is used.     

Vertebral artery-posterior inferior cerebellar artery bypass with a superficial temporal artery graft to treat aneurysms involving the posterior inferior cerebellar artery

OBJECT: In patients with aneurysms that require occlusion of the posterior inferior cerebellar artery (PICA), revascularization of this artery should be performed. A novel surgical method for revascularization of the PICA is presented. METHODS: After a segment of the superficial temporal artery (STA) was harvested, the aneurysm was treated by trapping, followed by placement of a vertebral artery (VA)-PICA bypass in which the STA segment was used as a graft. When the length of the proximal PICA was inadequate, the distal end of the STA was anastomosed to the proximal PICA in an end-to-side fashion. When the length of the proximal PICA was adequate, the STA was anastomosed to the proximal PICA in an end-to-end fashion. In either case, the proximal end of the STA was anastomosed to the VA in an end-to-side fashion. This procedure was used in nine patients whose aneurysms involved the PICA. Although partial lateral medullary syndrome developed in one of them, follow-up evaluation revealed graft patency in all patients. There were no instances of recurrent hemorrhage or ischemia. CONCLUSIONS: Although this procedure requires harvesting of an STA graft and two anastomoses, it facilitates anterograde flow to the PICA territory. It also involves minimal mobilization of brainstem perforating vessels and the proximal PICA.     

Vertebral artery occlusion with vertebral artery-to-posterior inferior cerebellar artery stenting for preservation of the PICA in treating ruptured vertebral artery dissection

We report a patient with a right vertebral artery (VA) dissecting aneurysm who was treated by placing an Enterprise stent (Cordis Neurovascular, Miami Lakes, FL) from the proximal VA to the posterior inferior cerebellar artery (PICA) in order to save the patency of the PICA. A 47-year-old man was admitted with a ruptured right VA dissecting aneurysm that involved the origin of the PICA. A 4.5 × 37-mm Enterprise stent was then placed through the proximal VA to the PICA. The dissected segment of the VA was completely occluded by coil embolization. The 1-year follow-up angiography showed that the dissected segment was completely occluded and the diameter of the PICA was slightly increased, and the PICA’s patency was good.     

裸支架在孤立性内脏动脉夹层治疗中的应用

目的:探讨裸支架在内脏动脉夹层治疗中的安全性及疗效。方法:2008年4月—2012年3月,6例内脏动脉夹层患者接受裸支架腔内治疗。其中,肠系膜上动脉夹层5例,腹腔干动脉夹层1例,分别采用单层或双层裸支架叠加技术隔绝夹层破口及瘤体。结果:6例手术均顺利,无并发症发生,腹腔干动脉夹层患者与1例肠系膜上动脉夹层患者植入双层裸支架后假腔即刻不显影,另4例植入单层或双层裸支架3个月后CT或彩超复查提示假腔闭塞、真腔通畅。结论:采用单层裸支架或双层裸支架叠加技术,是治疗内脏动脉夹层可行、有效、安全的方法。     

Treatment of extracranial and intracranial aneurysms and arteriovenous fistulae using stent grafts

OBJECTIVE: Treatment of 11 patients with aneurysms or arteriovenous fistulae of the craniocervical arteries with stent grafts. METHODS: Peripheral stent grafts were deployed in two extracranial internal carotid arteries. Coronary stent grafts were used to treat two giant aneurysms, five direct carotid-cavernous fistulae, one vertebrojugular fistula, and two dissecting aneurysms of the vertebral artery (V2 and V4). RESULTS: Stent grafts were used successfully in two extracranial internal carotid and two extracranial vertebral arteries, one dissecting aneurysm of the intracranial vertebral artery, one giant aneurysm and one pseudoaneurysm of the cavernous internal carotid artery, and five direct carotid-cavernous sinus fistulae. Angiographic follow-up examinations (available in nine patients; obtained at 3 mo to 5 yr; average, 24 mo) revealed normal vessel caliber, and the stent grafts in all 9 of 11 initial patients were patent. There was a recurrent saccular aneurysm adjacent to the stent graft in the patient with the intracranial vertebral artery aneurysm. The following five complications were encountered: transient hemiparesis (n = 2), increased hemiparesis, postprocedural management-related fatality, and ICA dissection. In six patients, stent graft deployment was accomplished without any technical or clinical complication. There were no permanent neurological deficits consequent to stent graft placement. CONCLUSION: Stent grafts are a useful tool for the endovascular treatment of head and neck aneurysms and direct arteriovenous fistulae in selected patients. The major disadvantage of the currently available stent grafts is their lack of mechanical flexibility. Maneuvering stent grafts in the intracranial arteries carries the risk of iatrogenic vessel dissection and may require supportive measures and protection of the target site by conventional stents.     

Aneurysms of the posterior inferior cerebellar artery-vertebral artery complex: variations on a theme

Aneurysms of the posterior inferior cerebellar artery-vertebral artery complex are relatively uncommon lesions. They include aneurysms at the origin of the posterior inferior cerebellar artery (PICA-VA), aneurysms on the distal artery (PICA) and aneurysms at the junction of the vertebral and basilar arteries (VA-BA). We have had the opportunity to treat 17 patients and study the radiological records of 9 additional patients in the past 8 years. The aneurysms ranged in size from 3 to 30 mm, with mean values of 10.6, 7.3, and 9 mm for PICA-VA lesions, distal PICA lesions, and VA-BA lesions, respectively. Three of the 4 VA-BA aneurysms were located at the midline, and the mean distance of the PICA-VA aneurysms from the midline was 7.6 to 9.4 mm; 2 aneurysms crossed the midline from their parent VA. The aneurysms were located slightly more often on the left side (left:right ratio, 1:2), were found more frequently in women (2.25:1), and occurred at a mean age of 50 years. Ten aneurysms at the origin of the PICA and 4 VA-BA aneurysms were treated via a lateral suboccipital craniectomy; 3 distal PICA aneurysms were exposed by a midline craniectomy. Surgery was carried out acutely in 5 patients. Tortuousness of the VA required contralateral approaches in 2 patients, an exploratory craniectomy in 1 patient, and an approach toward the dome of 1 patient with a VA-BA aneurysm. Morbidity was primarily due to cranial nerve dysfunction. There were no perioperative deaths. These aneurysms can easily be missed on initial radiographic examination; one appeared only on the second study, one was seen to grow over 16 days, and one was discovered at the level of C1 extracranially. Our radiographic and surgical approach to the treatment of these lesions is presented.     

Clinical presentation and treatment of distal posterior inferior cerebellar artery aneurysms

Aneurysms located at the distal portion of the posterior inferior cerebellar artery (PICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of 30 distal PICA aneurysms in 28 patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes 20 women and eight men. Of their 30 aneurysms, 24 were ruptured, and six were unruptured; there were 27 saccular and two fusiform aneurysms; one was dissecting. Their location was at the anterior-medullary (n?=?4), lateral-medullary (n?=?9), tonsillomedullary (n?=?7), telovelotonsillar (n?=?6), and cortical (n?=?4) segment of the PICA. In 18 patients, angiographic features suggested hemodynamic stress including an absent contralateral PICA or ipsilateral anterior inferior cerebellar artery, termination of the vertebral artery (VA) at the PICA, and hyperplasia or occlusion of the contralateral VA. As three patients died before surgery, 27 aneurysms in 25 patients were surgically treated. Of these, 6 were unruptured aneurysms; 20 were clipped via midline or lateral suboccipital craniotomy, and 5 were embolized with Guglielmi coils; in one, the PICA flow was reconstructed by OA-PICA anastomosis, and in the other one, the PICA was resected. Of the 25 surgically treated patients, 22 (88%) had good outcomes. The predominant contributor to the development of distal PICA aneurysms is thought to be increased hemodynamic stress attributable to anomalies in the PICA and related posterior circulation. Both direct clipping and coil embolization yielded favorable outcomes in our series. However, considering the difficulties that may be encountered at direct clipping in the acute stage and the availability of advanced techniques and instrumentation, aneurysmal coiling is now the first option to address these aneurysms.     

Combined endovascular treatment of dissecting vertebral artery aneurysms by using stents and coils

OBJECT: With the recent development and refinement of endovascular stents, the significant potential for these devices in the treatment of wide-necked dissecting and fusiform aneurysms has become apparent. In this article the authors report on the use of stents and coils to treat dissecting and fusiform vertebral artery (VA) aneurysms. METHODS: Eight consecutive patients harboring eight dissecting aneurysms and one fusiform aneurysm of the VA were succesfully treated using a procedure in which the authors inserted an intravascular stent and secondary endosaccular coils when needed. In all but one patient complete aneurysm occlusion was achieved, and in all cases there was no neurological complication. Follow-up angiography examinations were performed in all patients (mean duration of follow-up angiography review 13.1 months, range 3-42 months). The patients remained stable throughout the clinical follow-up period (mean 14.1 months, range 4-42 months). No rebleeding was recorded. CONCLUSIONS: At present this combined approach represents a reliable and safe alternative for the treatment of VA dissecting aneurysms, especially in patients who cannot tolerate occlusion tests.     

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion

BACKGROUND: In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion. METHODS: After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm. RESULTS: Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits. CONCLUSION: PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.     

A case of neurofibromatosis type 1 associated with arteriovenous fistula caused by re-bleeding of a vertebral dissecting aneurysm

We described a dissecting aneurysm of the vertebral artery (VA), which was associated with neurofibromatosis type 1 (NF1). A 41-year-old man was referred to our hospital because of abrupt, severe headache. A CT scan revealed diffuse subarachnoid hemorrhage (SAH) predominantly in the prepontine cistern. The angiograms showed a string sign in the left VA, just distal to the posterior inferior cerebellar artery (PICA). The vertebral dissection was considered responsible for SAH, and endovascular occlusion of the left VA was attempted. During the intervention, the patient complained of severe neck pain at the time of selective vertebral angiography, which revealed an arteriovenous fistula. The VA was occluded proximal to the PICA with GDC, which covered the fistula. Open surgery confirmed the two unruptured aneurysms. Intracranial dissection is rarely reported in association with NF1. However, ateriovenous fistula is not an uncommon combination with dissecting aneurysm and the extracranial segment of the VA is a characteristic target. Anatomical feasibility is conceivably the pathogenesis.     

Immediate and midterm follow-up results of using an electrodetachable, fully retrievable SOLO stent system in the endovascular coil occlusion of wide-necked cerebral aneurysms

OBJECT: Stent-assisted embolization is an alternative endovascular treatment method for wide-necked intracranial aneurysms. Currently available stents have the limitations of poor radial force, difficult delivery systems, and lack of full retrievability. The authors report on their preliminary experience with the use of a new, fully retrievable, self-expanding neurovascular stent, which has a high radial force and easy delivery system, combined with coil or Onyx embolization for the treatment of wide-necked aneurysms, including 6-month follow-up data. METHODS: Fifteen patients with 18 wide-necked intracranial aneurysms were treated using the SOLO stent system and detachable platinum coils. Aneurysms were located at the posterior communicating artery (seven lesions), midbasilar artery (one lesion), internal carotid artery (ICA) bifurcation (one lesion), ICA-ophthalmic artery segment (eight lesions), and posterior cerebral artery (one lesion). Eleven aneurysms were small, six were large, and one was giant. Only one of these aneurysms was in the acute stage of subarachnoid hemorrhage; balloon remodeling alone failed to keep the coils in the aneurysm sac. RESULTS: Only one stent required retrieving and repositioning after it had been fully deployed, and retrieval was easy and successful. No thromboembolic complication, dissection/rupture, or vasospasm occured during stent placement. Follow-up angiograms obtained at 6 months posttreatment in the 18 aneurysms demonstrated that all stents were patent with no evidence of intimal hyperplasia or stenosis. In all cases but one, 100% lesion occlusion was observed at the 6-month control angiography examination. Only one aneurysm had recanalized. CONCLUSIONS: The fully retrievable self-expandible SOLO stent is a feasible, secure, and effective system with a high radial force and ease of delivery in treating wide-necked intracranial aneurysms in combination with coil embolization.     

Dissecting aneurysms of the posterior inferior cerebellar artery: retrospective evaluation of management and extended follow-up review in 6 patients

OBJECT: The authors report the management protocol and successful outcomes in 6 patients with dissecting aneurysms of the posterior inferior cerebellar artery (PICA). METHODS: Medical records and neuroimaging studies of 6 patients who underwent surgical treatment of dissecting PICA aneurysms were reviewed. The mean follow-up duration was 1.8 years. No patient was lost to follow-up review. RESULTS: Four patients presented with acute subarachnoid hemorrhage and 2 with PICA ischemia. All patients underwent surgery, which entailed proximal occlusion with distal revascularization in 3 cases and circumferential wrap/clip reconstruction in 3 cases. The revascularization techniques used were occipital artery-PICA bypass and PICA-PICA anastomosis. Delayed follow-up angiography was performed in all cases. In patients treated with proximal occlusion, delayed angiography showed minimal retrograde opacification of the dissected segments. The 3 patients treated with wrap/clip reconstruction showed unexpectedly significant normalization of their lesions on angiographic studies. Outcome was good in all cases. CONCLUSIONS: Dissecting PICA aneurysms are rare lesions with an apparent propensity for bleeding. Individualized management including distal revascularization with PICA sacrifice or circumferential wrap/clip reconstruction to reinforce the dissected segment produced good outcomes. Patients treated with aneurysm wrapping may show dramatic angiographic improvement of the dissected segment.     

Clinical analysis of a series of vertebral aneurysm cases.

We reviewed 38 cases of aneurysms of the vertebral artery treated over the last 10 years: 26 (68%) located at the junction of the vertebral and posterior inferior cerebellar arteries, 10 (26%) at the vertebral artery, and 2 (5%) at the vertebrobasilar union. There were three distinct forms of aneurysms: 20 saccular (53%), 10 fusiform (26%), and 8 dissecting (21%). Among these 38 aneurysms, 33 (87%) had ruptured: 18 of the saccular aneurysms (90%), all 10 of the fusiform aneurysms (100%), and 5 of the dissecting aneurysms (63%). Computed tomography of the 28 ruptured aneurysms revealed diffuse subarachnoid hemorrhage in the basal cistern combined with intraventricular hemorrhage in 24 cases (86%). Magnetic resonance imaging was useful for differentiating between fusiform and dissecting aneurysms. Abnormalities such as a double lumen of the vertebral artery were demonstrated in four of the dissecting aneurysms. The overall surgical results were good for 22 of the 27 surgically treated cases (81%). New bleeding was observed in 8 (24%) of the 33 ruptured aneurysms. The rate of new bleeding was high (60%) in the patients with dissecting aneurysms, and occurred mostly in the acute stage. The incidence of vasospasm was 27%, and only two patients suffered permanent neurological deficits. These findings indicate that the rate of new bleeding tends to be high in patients with saccular and dissecting aneurysms, and thus, they should be treated as early as possible. A preoperative balloon occlusion test should be conducted if proximal occlusion of the vertebral artery is necessary, since proximal occlusion is not always safe, despite angiographic evidence of sufficient contralateral arterial flow.     

椎动脉-小脑后下动脉梭形动脉瘤的手术治疗

目的 探讨手术治疗椎动脉-小脑后下动脉梭形动脉瘤的方法.方法 回顾性分析2007年12月至2010年2月收治的5例椎动脉-小脑后下动脉梭形动脉瘤患者的临床特点、手术方法及疗效.5例患者均为男性,年龄40～55岁,平均47岁.其中动脉瘤破裂出血4例,1例表现为后枕部阵发性头痛.所有患者均采用远外侧入路,翻开皮肌瓣后,先于枕部肌群内分离枕动脉,开颅后显露同侧小脑后下动脉尾襻,并于此处行枕动脉-小脑后下动脉吻合重建小脑后下动脉血流,再行动脉瘤孤立术或切除术.术后进行随访,观察疗效.结果 5例患者术后1例无神经功能缺失;3例有后组脑神经功能障碍;1例出现颅内血肿,二次手术后并发对侧肢体偏瘫.行数字减影血管造影或CT血管造影检查,吻合口通畅,动脉瘤不显影.随访2～29个月,平均18个月,4例预后良好,1例对侧肢体轻偏瘫.结论 枕动脉-小脑后下动脉搭桥+动脉瘤孤立或切除术是治疗椎动脉-小脑后下动脉梭形动脉瘤的有效方法,但需结合实际情况,选择个体化的治疗方案.     

Multiple spontaneous dissecting aneurysms of the anterior cerebral and vertebral arteries

A 50-year-old woman presented with rare multiple dissecting aneurysms that appeared first in the anterior cerebral artery (ACA) and shortly afterwards in the vertebral artery (VA). She initially suffered sudden motor weakness in the left lower limb due to acute brain infarction. Angiography revealed diffuse string sign in the right ACA. Conservative treatment resulted in resolution of the deficits. Follow-up angiography performed 1 year later revealed recovery of the ACA stenosis. Fourteen days later, she complained of sudden headache and became comatose. Computed tomography showed diffuse subarachnoid hemorrhage. Angiography revealed a new right VA dissecting aneurysm involving the posterior inferior cerebellar artery (PICA). The orifice of the dissection was not apparent in the operative field and the dissection extended to the median. The patient underwent extracranial right VA ligation, clipping of the proximal PICA, and revascularization between the right occipital artery and distal PICA. Her postoperative course was uneventful and she was discharged without neurological deficits. VA dissecting aneurysms involving the PICA without evident orifice or extending over the median can be treated by extracranial ligation with clipping of the PICA, followed by revascularization.     

Four cases of abducens palsy caused by a vascular lesion of the vertebrobasilar system

Several pathological conditions are responsible for abducens palsy, but a lesion of the vertebral artery (VA) has rarely been recognized as one of the causes. It has been reported that a high percentage of cases of abducens palsy are involved with ruptured dissecting aneurysms of the VA. We investigate the vertebrobasilar anatomy in 4 patients, suffering with abducens palsy. One patient revealed a fusiform dilatation of the vertebral artery on the same side as the abducens palsy. Three patients were noted to have stenosis of the vertebral artery from the origin of the posterior inferior cerebellar artery (PICA) to the union. Finally, four patients were found to have abnormal vertebrobasilar anatomy, which was on the same side as the abducens palsy. It is conceivable that changes of vertebrobasilar circulation may cause abducens palsy through direct compression, or ischemic events.