Giant Vertebrobasilar Aneurysms Research Articles

High-flow bypass for giant dolichoectatic vertebrobasilar aneurysms: illustrative cases

BACKGROUND Giant fusiform dolichoectatic vertebrobasilar artery aneurysms are challenging lesions with a poor natural history. When there is progressive brainstem compression from these lesions, endovascular treatment can be insufficient, and bypass surgery remains a possible salvage option. High-flow bypass surgery with proximal occlusion can potentially arrest aneurysm growth, promote aneurysm thrombosis, and reduce rupture risk. The authors describe their experience in two patients with giant fusiform dolichoectatic vertebrobasilar artery aneurysms treated with high-flow bypass. OBSERVATIONS Both patients presented with enlarging giant dolichoectatic vertebrobasilar aneurysms causing symptomatic brainstem compression. The authors performed staged treatment involving high-flow bypass from the external carotid artery to the posterior cerebral artery using a saphenous vein graft, Hunterian proximal vertebrobasilar occlusion, and finally posterior fossa decompression with or without direct aneurysm thrombectomy and debulking. Postoperative angiography revealed successful flow reversal, aneurysm exclusion, and no brainstem stroke. Clinically, one patient had improvement in their modified Rankin Scale (mRS) score from 3 preoperatively to 1 at 12-month follow-up. The second patient had a deterioration in their mRS score from 4 to 5 at 12-month follow-up. LESSONS High-flow bypass strategies remain high risk but can be a viable last resort in patients with neurological deficits and enlarging giant fusiform dolichoectatic vertebrobasilar artery aneurysms.

Abstract Number ‐ 137: Delayed aneurysmal rupture of a giant fusiform vertebrobasilar aneurysm after flow‐diversion embolization with adjunctive coiling

Introduction Vertebrobasilar aneurysms carry a high risk of operative morbidity and high mortality risk with rupture. Treatment with flow diversion embolization has gained popularity. While adjunctive coiling may lower the risk of delayed aneurysm rupture (DAR), DAR can occur during stent endothelialization. describe a case of DAR following flow diversion with adjunctive coil embolization of a giant vertebrobasilar aneurysm and review the literature to further characterize this phenomenon. Methods PubMed was queried using search terms: “delayed,” “aneurysm,” “rupture,” “flow diverter,” “flow diversion,” and “flow diverting stent” yielding 220 results. There were 47 studies describing 89 patients with DAR after flow diversion. Results A forty‐five‐year‐old male presented with posterior fossa compression symptoms secondary to a 30‐mm fusiform basilar artery aneurysm, which grew during short‐interval follow‐up to 35 mm. The patient consented to endovascular embolization. Tri‐axial catheter access system was used to deploy seven telescoping flow diverters from the basilar tip to the intradural left vertebral artery, and nine coils were subsequently deployed in the aneurysm dome. The right vertebral artery was coil embolized. The procedure was uncomplicated and the patient was continued on dual‐antiplatelet therapy. Four weeks later, the patient became unresponsive with absent brainstem reflexes, workup revealed diffuse subarachnoid hemorrhage with intraventricular hemorrhage. Digital subtraction angiography demonstrated contrast extravasation at the aneurysm neck. He succumbed to his neurological injury two days later. Out of 89 patients with DAR after flow diversion, only 3 occurred in fusiform basilar aneurysms treated with adjunctive coil embolization. Only one case, a 37.1‐mm aneurysm treated with 3 flow diverters with adjunctive embolization, occurred at greater than 30 days post‐intervention. Conclusions This case highlights the need to better characterize the role of adjunctive coiling with flow diversion for large or giant aneurysms, and to better understand risk factors related to delayed aneurysm rupture.

Abstract Number ‐ 121: Flow Diversion Jet: A Dangerous Mechanism in the Flow Diversion Treatment of Giant Intracranial Aneurysms

Introduction We present a patient with a giant vertebrobasilar system aneurysm. This case provides an in‐depth analysis of the pathologic mechanism resulting in catastrophic distal hemorrhage following stent deployment due to the shared effects of normal perfusion pressure breakthrough (NPPB) and the Windkessel phenomenon. The Windkessel phenomenon and NPPB occur before and after treatment of various vascular malformations, respectively. These phenomena are hypothesized to contribute to the loss of cerebrovascular autoregulation. High flow lesions and giant aneurysms reduce blood flow in downstream vessels, causing chronic distal vasodilation to protect against ischemia. Sudden restoration of normal pulsatile flow, following treatment, compromises the integrity of distal vessels leading to potential catastrophic intracerebral hemorrhage. Methods A retrospective review of the patient’s medical record was performed. Results A 60‐year‐old female initially presenting with pulsatile neck mass was found to have dolichoectasia of the right cervical internal carotid artery and two large, irregular, vertebrobasilar aneurysms. Managed conservatively for 10 years before developing gait ataxia, new imaging revealed growth of the now giant, more distal aneurysm. Flow diversion with partial coiling of the aneurysms was pursued. Following deployment, DynaCT demonstrated catastrophic thalamic and midbrain hemorrhage with intraventricular extension. A review of intra‐aneurysmal pressure measurements, angiography, MRI, and neuromonitoring data strongly suggests rupture of multiple deep perforators following the conversion to laminar flow when the flow diverting chain was finalized. This suggests giant aneurysms chronically depress the distal pulse pressure by acting as a Windkessel reservoir. Flow diversion bypasses the reservoir increasing pulse pressure distal to the aneurysm, exceeding autoregulatory capacity, leading to hemorrhage. Conclusions This is the first case in the literature to describe NPPB and the Windkessel phenomenon in the attempt to treat giant aneurysms with flow diversion. Flow diversion bypasses the reservoir, suddenly changing turbulent flow to laminar flow. The resultant dramatic rise in pulse pressure distal to the aneurysm can exceed the autoregulatory mechanisms of small distal vessels such as perforating branches. While demonstrating a poor outcome, awareness of these mechanisms and meticulous intra‐operative blood pressure management may reduce or prevent complications. Further modeling of flow dynamics both before and following treatment of these aneurysms may lead to altered guidelines in the temporality of treatment due to potential catastrophic sequelae.

Combined deconstructive and reconstructive treatment of a giant vertebrobasilar fenestration aneurysm.

Aneurysms associated with a vertebrobasilar fenestration are rare lesions and can grow to a giant size, presenting significant therapeutic challenges. Endovascular treatment of these aneurysms has traditionally been with coiling; however, flow diverter placement within the fenestration arms has recently proven to be a viable treatment strategy. The authors present a case of a giant vertebrobasilar fenestration aneurysm in a patient presenting with a cranial nerve VI palsy. The lesion was treated by using a combination of flow diverter placement and vertebral artery sacrifice. The nuances of flow diversion therapy for these aneurysms and the management of intra- and postoperative complications are discussed. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2256.

Pipeline Embolization Device With Adjunctive Coils for the Treatment of Unruptured Large or Giant Vertebrobasilar Aneurysms: A Single-Center Experience.

Objective: To evaluate effectiveness and safety of Pipeline embolization device (PED) for large or giant verterbrobasilar aneurysms (LGVBAs), and to compare the therapeutic effects of PED with and without adjunctive coils.Methods: We retrospectively analyzed 21 cases of unruptured LGVBAs who were treated in our hospital with PED. These cases were divided into “PED group” and “PED with adjunctive coils group.” We compared the aneurysm characteristics and treatment outcomes between the two groups.Results: The overall neurological complication rate was 28.6% (6/21) and the mortality rate was 4.8% (1/21). There were 12 patients in the PED group and nine in the PED with adjunctive coils group. There were no significant differences in age, smoking, hypertension, aneurysm size, aneurysm location, or operation time between the two groups. The complete aneurysm embolization rate and favorable outcome rate (modified Rankin Scale = 0,1) of the PED with adjunctive coils group was 78% (7/9) and 100% (9/9), respectively, which were both better compared with the PED group with 63.6% (7/11) and 83% (10/12), respectively. However, these differences were not statistically significant.Conclusion: The effectiveness and safety of PED for LGVBAs is acceptable. Treatment results did not differ between the PED and PED with adjunctive coils groups; therefore, whether coils should be used may depend the operator. Our results suggest that correct use of the coils does not increase complications. We suggest that PED with adjunctive coils should be used for some selected LGVBAs.

Unfavorable Outcomes Related to Endovascular Treatment of Giant Vertebrobasilar Aneurysms.

Background: Giant vertebrobasilar aneurysms (GVBAs) have an unfavorable natural history if left untreated and often pose a sizeable challenge to endovascular treatment. The aim of this study was to analyze the angiographic and clinical outcomes of GVBAs treated by various endovascular procedures.Methods: Between January 2010 and September 2018, 27 patients with 27 GVBAs treated endovascularly were enrolled in this consecutive study. The clinical and angiographic features, treatment modalities, and outcomes were analyzed.Results: The patient cohort comprised 21 men (77.8%) and 6 women (22.2%) of mean age 42.7 ± 18.9 years (range, 6–65 years). The most common presenting symptom was compressive symptoms, present in 15 patients (55.6%). None of the GVBAs was ruptured. Of the 27 GVBAs, 23 aneurysms were dissecting aneurysm with intramural hematoma and 4 aneurysms were saccular. Regarding treatment approach, internal trapping was used in 5 aneurysms, stent-assisted coil embolization in 10, sole stenting in 4, and flow diverters in 8. Overall, 12 patients (44.4%) had an unfavorable angiographic or clinical outcome: 3 patients presented with post-operative complications and subsequent death, and 9 with poor prognosis during follow-up.Conclusions: Patients with GVBAs may not benefit from endovascular treatment. Newer-generation devices are necessary to provide more optimal therapy for the management of these complex lesions.

Pediatric Patient With a Giant Vertebrobasilar Dissecting Aneurysm Successfully Treated With Three Pipeline Embolization Devices.

Pediatric intracranial dissecting aneurysms are rare (1), and treating this type of aneurysm in the vertebrobasilar circulation is more difficult. As an off-label application, pipeline embolization devices (PEDs) for posterior circulation dissecting aneurysms are reported to have good therapeutic effect (2). However, studies have found that PEDs for large or giant vertebrobasilar dissecting aneurysms have a poor effect and are associated with disastrous consequences for patients (3). PEDs are feasible for vertebrobasilar dissecting aneurysms (4); however, few reports discuss using PEDs to span the entire segment of the basilar artery. Because there are more perforating arteries in the basilar artery, it is more prudent to use PEDs in this artery. We report a case of a pediatric patient with a giant vertebrobasilar dissecting aneurysm successfully treated with three PEDs combined with right vertebral artery occlusion, without complications. The patient's headache symptoms resolved fully 3 months after the procedure, and the aneurysm was completely healed and excellent reconstruction of the left vertebral artery was seen 4 months post-procedure, using digital subtraction angiography.

Endovascular Treatment of Large or Giant Non-saccular Vertebrobasilar Aneurysms: Pipeline Embolization Devices Versus Conventional Stents.

BackgroundEndovascular treatment of large or giant non-saccular vertebrobasilar aneurysms (VBAs) by conventional stents is difficult and has unsatisfactory outcomes.ObjectThis study was performed to retrospectively analyze the safety and efficacy of a flow diverter in treating large and giant non-saccular VBAs.MethodsWe identified 78 patients with 83 large or giant non-saccular VBAs who accepted endovascular treatment with a pipeline embolization device (PED) or conventional stent from January 2014 to June 2018. The technical details of the procedure, procedure-associated complications, angiographic outcomes, and clinical outcomes were evaluated.ResultsForty-two patients (53.8%, 42/78) with 44 aneurysms (53.0%, 44/83) underwent endovascular treatment with PEDs. Thirty-six patients (46.2%, 36/78) with 39 aneurysms (47.0%, 39/83) underwent endovascular treatment with conventional stents. The complication rate of PED group and conventional stent group was 7.1% (3/42) and 5.6% (2/36), respectively (odds ratio, 0.765; 95% confidence interval, 0.121–4.851; P = 0.776). During a median follow-up time of 28.8 months, the complete occlusion rate in the PED group and conventional stent group was 90.2% (37/41) and 70.3% (26/37), respectively (odds ratio, 3.913; 95% confidence interval, 1.122–13.652; P = 0.032).ConclusionEndovascular treatment with a PED is a promising and safe modality for large and giant non-saccular VBAs, and the complication rate is acceptable, compared with conventional endovascular treatment.

Application of the Pipeline Embolization Device for Giant Vertebrobasilar Dissecting Aneurysms in Pediatric Patients.

Objective: To evaluate the feasibility and effectiveness of the pipeline embolization device (PED) for the treatment of pediatric giant vertebrobasilar dissecting aneurysms (VBDAs).Methods: We retrospectively reviewed our institutional clinical database and identified 2,706 patients who presented with a diagnosis of intracranial aneurysms from January 2016 to June 2018. Among this group, 153 patients were diagnosed with VBDAs, and 54 of these patients underwent PED therapy. The PED technique was used in four patients who were 18 years old or younger at the time of presentation (two males, two females; mean age 9.25 years; age range 8–11 years).Results: All four included pediatric patients were managed with the PED. One patient (25%) was treated with the PED alone, while three (75%) were treated with the PED and coils. One patient died from brainstem infarction or compression of the brainstem, while follow-up of the other three patients revealed favorable outcomes. The mass effect was reduced in cases 1, 2, and 3 on follow-up MRI performed 6 months after the PED procedure.Conclusions: PEDs could be feasible in the treatment of pediatric giant VBDAs. However, the safety and efficacy of this method have not been clarified in this special pediatric population, and long-term follow-up is still necessary.

Reconstructive endovascular treatment of symptomatic large or giant unruptured vertebrobasilar fusiform aneurysm with LVIS stent-assisted partial coil embolization

Abstract Objectives Large or giant vertebrobasilar fusiform aneurysms (VFAs) remain one of the most formidable lesions. The purpose of this study was to evaluate the technical feasibility, clinical and angiographic outcomes of LVIS SACP-SWS technique in patients with large or giant unruptured VFAs. Patients and methods Eleven patients with large or giant unruptured VFAs underwent LVIS SACP-SWS technique between Jun 2015 and May 2017. Thirty-eight (38) LVIS stents were completely deployed at desired position. Outcomes were evaluated based on the modified Rankin Scale (mRS) score and angiography. Results The LVIS SACP-SWS was successful without any treatment-related complications in all 11 patients. In regard to clinical outcome, mRS was 3.55 ± 1.29 at pre-operative stage that significantly (p = 0.01) decreased to 1.91 ± 1.92 at last follow-up. The mean decrease in mRS was 1.63 ± 1.69. Near-complete occlusion of dissecting aneurysmal sac (NO) was seen in 5 patients at DSA follow-up and complete occlusion of dissecting aneurysmal sac (CO) was in 4 patients, the remaining patient was re-treated by occluding the V4 segment of right verbal artery. Conclusions Our results provide an encouraging support for the LVIS stent-assisted coil partial embolization combined with stent-within-a-stent technique. Further studies of the technique as an alternative strategy for treatment of large or giant unruptured VFAs are warranted.

Parallel placement of multiple stents and reconstruction technique for the treatment of giant vertebrobasilar dissecting aneurysms: A medium and long-term follow-up study

Objective To investigate the medium and long-term follow-up results of parallel placement of multiple stents and reconstruction technique for treatment of giant vertebrobasilar dissecting aneurysms. Methods Clinical data of 6 consecutive patients with 6 giant vertebrobasilar dissecting aneurysms admitted to Department of Neurology, Chinese PLA General Hospital from April 2011 to August 2012 were retrospectively reviewed. All patients were diagnosed with vertebrobasilar dissecting aneurysms by DSA whose sizes ranged from 7.9 to 14.0 mm. All patients were treated with parallel placement of multiple stents and reconstruction technique under general anesthesia. Modified Rankin Scale (mRS) was used to evaluate the outcomes. Results Six patients were successfully implanted with 21 stents.All patients’signs and symptoms were improved significantly.The follow-up period ranged from 5 to 7 years.All patients underwent DSA reexamination at follow-up, The aneurysmal size was decreased in 3 patients and remained the same in 3 others.Five patients reported permanently improved symptoms. The last follow-up revealved the mRS of 0 in 1 case, 1 in 3 and 2 in 2. Conclusion Parallel placement of multiple stents and reconstruction technique for treatment of giant vertebrobasilar dissecting aneurysms could help control the dilatation of aneurysm in the medium and long-term follow-up and thus improve the patient’s clinical symptoms and quality of life. Key words: Intracranial aneurysm; Aneurysm, dissecting; Endovascular procedures; Vertebrobasilar artery; Treatment outcome

Surgical treatment of large and giant vertebrobasilar aneurysms manifested by brainstem compression symptoms

The study included 8 patients operated on in the period between 2014 and 2017. All patients underwent intravascular intervention; two patients had open surgery at the second stage. Intravascular intervention, both alone and in combination with open surgery, is effective treatment of VB aneurysms whose clinical picture is manifested by brainstem compression symptoms. The use of flow-diverting stents in most cases has provided good radicalness in the long-term period, without worsening the functional outcome. Treatment of fusiform aneurysms of the basilar artery trunk requires separate consideration and an individual approach due to a high risk of thrombosis of short branches feeding the brainstem.

Transclival Approach, Clipping and Drainage of a Giant Vertebrobasilar Aneurysm: Case Report

Introduction: Transclival approach for clipping vertebrobasilar junction aneurysms has been described since 1966; however, there is not register in the current literature using this approach for clipping and drainage of giant vertebrobasilar aneurysms, mainly because its inherent complications. Approach is intended to avoid brainstem and cranial nerves retraction. Endovascular treatment has not provide enough satisfactory results concerning to brainstem decompression.

A systematic review of pipeline embolization device for giant intracranial aneurysms.

The experience with respect to the treatment of giant intracranial aneurysms with flow-diversion devices is limited. The aim of the present systematic review was to evaluate the effect of the pipeline embolization device (PED) on giant intracranial aneurysms. Eligible related articles were identified by searching the PubMed, Web of Science, Springer, ScienceDirect, and OVID databases using "giant aneurysm" and "pipeline" as the search items. The date of the last search was November 20, 2015. This systematic review adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In a total of 9 eligible studies with 200 patients and 215 aneurysms, 40 (18.6%) giant (aneurysm diameter >25mm) intracranial aneurysms treated with PED were analyzed. During a 6 to 34 month follow-up, complete occlusion was achieved in 23 (57.5%) cases. Seven patients (17.5%) developed intracranial hemorrhage, 5 developed ischemic attack (12.5%), and 13 (32.5%) developed a mass effect after PED treatment. The complication rate was 77.8% in PED for giant vertebrobasilar artery aneurysms. The cumulative mortality rate for giant paraclinoid carotid artery and middle cerebral artery aneurysms was 13.3% and increased up to 50% for giant vertebrobasilar artery aneurysms. The complete obliteration rate of PED for giant intracranial aneurysms was approximately 60%. Mass effect is the most mechanism of complications. Complication and mortality rates associated with PED for giant vertebrobasilar artery aneurysms are still extremely high.

Giant Fusiform Vertebral Artery Aneurysm Treated with Microsurgical Bypass and Endovascular Coiling after Failed Flow Diversion: A Case Report and Discussion

Background Giant vertebral and vertebrobasilar aneurysms have proven to be extremely challenging vascular entities to treat despite many advances in microsurgical and endovascular techniques. In recent years, there has been more attention paid to combined approaches, including combinations of endovascular and surgical procedures in hopes of decreasing the associated morbidity and mortality of these lesions. Clinical Presentation We present a case of a giant fusiform vertebral artery aneurysm that was initially treated with flow-diverting stents. After the failure of flow diversion to occlude the aneurysm, the lesion was definitively treated with an occipital artery to the posterior inferior cerebellar artery (PICA) bypass and coil embolization of residual aneurysm. Conclusion After bypass and parent vessel deconstruction, angiography confirmed the aneurysm has remained occluded and the PICA patent. This case highlights the use of an extracranial-to-intracranial bypass to salvage a complex residual aneurysm after failed flow diversion.

Magnetic Resonance Imaging Follow-Up of Large or Giant Vertebrobasilar Dissecting Aneurysms After Total Embolization on Angiography

To evaluate the outcomes of large or giant vertebrobasilar dissecting aneurysms (VBDAs) after endovascular total embolization by follow-up 3T magnetic resonance imaging (MRI). Between November 2011 and July 2015, 4 patients had unruptured large or giant VBDAs that were treated with endovascular techniques with total embolization of VBDAs confirmed on follow-up angiography, but the patients had persistent or worsened symptoms. Preoperative and postoperative 3T high-resolution MRI was performed to evaluate arterial wall evolution. Follow-up angiographic results were satisfactory in all 4 patients; however, symptoms in cases 1, 2, and 4 worsened, and symptoms in case 3 did not improve. Postoperative high-resolution MRI in case 1 showed a new intramural hematoma, and postoperative high-resolution MRI of cases 2, 3, and 4 showed persistent intramural hemorrhagic signals. Follow-up MRI showed increased aneurysm size in cases 1, 2, and 4 but no size change in case3. The efficacy of conventional endovascular treatment (e.g., internal trapping with coils, stent-assisted coiling, and stent placement without coils) for large or giant VBDAs is uncertain. Follow-up angiography alone does not adequately predict the outcome. High-resolution MRI is a worthwhile adjunct to follow these lesions.

A challenging entity of unruptured giant saccular aneurysms of vertebrobasilar artery

PurposeGiant intracranial aneurysms commonly cause poor clinical outcome and few studies focus on them. This study is to retrospectively report the angiographic and clinical presentations in unruptured giant saccular vertebrobasilar aneurysms with and without endovascular treatment. MethodsOut of 400 patients who had unruptured posterior circulation aneurysms in a single center, we found 10 unruptured giant (>25mm) saccular vertebrobasilar aneurysms. Clinical and angiographic presentations as well as their clinical outcomes were assessed. ResultsOf the 10 giant aneurysms in 10 patients, three were left untreated. During 6 months follow-up, all 3 of these patients died from aneurysm rupture. The remaining 7 patients were treated by endovascular procedure, 5 received stent-assisted coiling, 1 was treated by parent artery occlusion (PAO), and 1 was treated by conventional coiling. Of these treated patients, only one survived during a 22 month period of follow-up. ConclusionsPatients with giant saccular aneurysms of vertebrobasilar artery presenting mass effect may have extremely poor clinical outcomes and may not benefit from endovascular treatment.

Endovascular treatment of unruptured posterior circulation intracranial aneurysms.

Background and Purpose:Endovascular treatment of unruptured posterior circulation intracranial aneurysms (UPCIAs) is limited in the International Study of Unruptured Intracranial Aneurysms (ISUIA). The aim of this study is to evaluate the periprocedural morbidity, mortality, and midterm clinical and angiographic follow-ups of endovascular treatment of UPCIAs.Materials and Methods:Retrospective analysis of all patients treated in a 2-year period (89 patients: 10–78 years of age, mean: 45.5 ± 14.3/92 UPCIAs). Fifty-eight aneurysms were found incidentally, 12 in association with mass effect symptoms and 22 with stroke.Results:A clinical improvement or stable outcome was achieved in 84 patients (94.4%). The two cases of permanent morbidity included a patient with paralysis and another patient with hemianopia. One patient died after treatment of a giant fusiform vertebrobasilar aneurysm. In one patient, the aneurysm ruptured during treatment, resulting in death. Another patient suffered a fatal aneurysm rupture 4 days after treatment. Giant size (P = 0.005) and mass effect presentation (P = 0.029) were independent predictors of unfavorable outcomes in UPCIAs. Angiographic follow-up was available in 76 of the 86 surviving patients (88.4%) with a mean of 6.8 months (range: 1–36 months). Recanalization in six patients (7.9%) at 3 months, 4 months, 4 months, 24 months, and 36 months required retreatment in three patients. In-stent stenosis of >50% was found in three patients.Conclusion:Endovascular therapy is an attractive option for UPCIAs with stable midterm outcome. However, the current endovascular option seems to have a limitation for the treatment of the aneurysm with giant size or mass effect presentation.

Short term effect of multiple stents parallel placement and reconstruction technique for the treatment of giant fusiform vertebrobasilar dissecting aneurysms

To investigate the feasibility,safety and follow-up results of multiple stents parallel placement and reconstruction technique for treating giant vertebrobasilar dissecting aneurysms. Five consecutive patients with giant fusiform vertebrobasilar dissecting aneurysms in Department of Neurology,Chinese People's Liberation Army General Hospital were retrospectively reviewed from April 2011 to October 2013. All patients were diagnosed vertebrobasilar dissecting aneurysms by MRI and digital subtraction angiography (DSA), the aneurysm size ranged 8.2-15.0 mm. All patients were treated by multiple stents parallel placement and reconstruction technique under general anesthesia. In the endovascular treatment process, 2-3 Solitaire or Neuroform self-expandable stents were parallel implanted in the maximum extension segment of the aneurysms to reconstruct the cavity of the aneurysm and solved the problem that the diameter of the intracranial stent is less than the diameter of the aneurysms. Multiple stents parallel placement can keep the stents stable in the cavity. The parallel stent can close the dissection as well as strengthen the aneurysm walls to alleviate the vessel pulsative compression of the brain stem. Furthermore, one of the parallel stents was selected for the main blood flow channel. Based on the main channel, telescope technique was used to completely covering the dissection. It can not only prevent the progress of dissection to normal regions, but also be helpful for blood flow channel reconstruction to reduce the hemodynamic disorders. All Patients received routine antiplatelet therapy before and after endovascular treatment. The operative procedures were succeeded in all patients. Five patients were implanted 18 stents (3 stents in 3 patients; 4 stents in 1 patient; 5 stents in 1 patient; parallel 3 stents in 2 patients; parallel 2 stents in 3 patients). The signs and symptoms of brain stem and posterior group of cranial nerves improved significantly. All patients lived and worked normally and had no recurrent symptoms on follow-up of 6-24 months. All patients performed DSA reexamination at 6-12 months postoperation. The aneurysm size lessened in 2 patients and had no change in 3 patients. Multiple stents parallel placement and reconstruction technique for treating giant fusiform vertebrobasilar dissecting aneurysms is feasible and have good operation safety. It may control the dilatation of the aneurysm and reduce the probability of thrombosis or hemorrhage. It can improve the patients' clinical symptoms and quality of life in short term follow-up. The long term result need for further follow-up.

Reconstructive Endovascular Treatment of Spontaneous Symptomatic Large or Giant Vertebrobasilar Dissecting Aneurysms: Clinical and Angiographic Outcomes.

To investigate the clinical and angiographic outcomes of spontaneous symptomatic large or giant vertebrobasilar dissecting aneurysms (VBDAs) following reconstructive endovascular treatment (EVT) with stent(s). We retrospectively identified 21 patients with spontaneous symptomatic large or giant VBDAs who had been treated with reconstructive EVT between September 2009 and September 2013 in our department. There were 20 men and 1 woman, with a mean age of 46.5 years (range: 17-67 years). Clinical and angiographic data were reviewed and evaluated. Reconstructive EVT with sole stenting (SS, 10 cases) or stent-assisted coiling (SAC, 11 cases) technique was technically feasible in all cases. Angiographic follow-up results confirmed delayed thrombosis of the aneurysm sac in only two of the eight cases after SS, and recurrence of the aneurysm sac in six of the nine cases after SAC. Postoperative complications or poor neurologic outcomes occurred in seven cases (33.3%). Three patients died after SS, including postoperative subarachnoid hemorrhage in one case and pulmonary embolism in one case. The other patient died soon after SAC, without radiologic result to confirm the causes of death. Other adverse events after treatment include ischemic complication in two cases, intramural hemorrhage in one case, aggravation of initial mass effect in one case. As to the other 14 cases, the post-procedural processes were uneventful and no complication was observed. The condition of them was improved in seven cases (33.3%), and unchanged in seven cases (33.3%) during follow-up. Reconstructive EVT with traditional intracranial stent(s) for the treatment of large and giant VBDAs carries a high failure rate and substantial risk of complications. The outcome of treating these difficult lesions with traditional intracranial stenting seems questionable and unpredictable.