Treatment Of Posterior Circulation Aneurysms Research Articles

Microsurgical treatment of posterior circulation aneurysms: an institutional experience from Nepal.

Management strategies and outcomes of patients with posterior circulation aneurysms are varied due to uncertainty in the optimal treatment modality and limited experience of neurosurgeons. Data are scarce regarding patients with posterior circulation aneurysms from developing countries. This study aims to describe the clinical characteristics, management strategies and outcome of patients with these aneurysms treated microsurgically in an academic institute in Nepal. The clinical records of patients confirmed to have posterior circulation aneurysms treated microsurgically between July 2014 and July 2022 were retrospectively reviewed. Demographic and clinical characteristics, morphometric characteristics of aneurysms, management strategies, postoperative complications, and 1-year outcomes were described. Out of 220 aneurysms in 190 patients, 20 were posterior circulation aneurysms. The median age of the patients was 43 (15-60) years. All were ruptured aneurysms. The admission Hunt and Hess grades of 18 (90%) patients were less than or equal to III. The posterior inferior cerebellar artery (8) was the commonest location. The postoperative complications rate was 20%, with the overall mortality of 10%. 80% of patients had a favourable outcome at 1-year follow-up. The patient characteristics and outcome are comparable with those described in the literature from other countries. With an individualized and careful selection strategy, our results are satisfactory despite fewer operations.

Flow Diversion for the Management of Posterior Circulation’s Intracranial Aneurysms

The endovascular treatment of posterior circulation aneurysms, although challenging, has been well-established due to various factors that limit the surgical approach in most cases. Flow diversion has also been utilized in the treatment of such aneurysms, although its effectiveness and safety still require evaluation. Numerous studies have examined the outcomes and complication rates in patients treated with FD, resulting in varying findings. This review aimed to summarize the most recent literature concerning the effectiveness of flow diversion devices in posterior circulation aneurysms. Additionally, it highlights reports that compare results in the posterior versus anterior circulation, as well as flow diversion versus stent-assisted coiling.

Endovascular treatment of posterior circulation aneurysms: Results from a single-team experience of 81 cases including 13 flow diversion treatment

IntroductionRelatively constant surgical risks and rapid advances in endovascular treatment have caused a major shift toward endovascular management of posterior circulation aneurysms. This paper presents the results of a series of endovascularly treated posterior circulation aneurysms. MethodsA total of 81 patients who underwent endovascular treatment of posterior circulation aneurysms performed by a single team between 2009 and 2019 were included. Demographic, clinical, radiologic, and management details were retrospectively obtained from hospital records. ResultsAmong the included patients, 50 (61.7%) and 31 (38.3%) were female and male, respectively. Subarachnoid hemorrhage was observed in 30 patients (37%). Moreover, 40 (49.3%) aneurysms were treated with stent-assisted coiling, 1 (1.2%) aneurysm was treated with parent artery occlusion, 2 (2.4%) aneurysms were coiled using balloon assistance, 24 (29.6%) aneurysms were coiled primarily, 1 (1.2%) patient had an unsuccessful treatment attempt, and 13 (16.0%) aneurysms were treated with flow-diverter stents or stent monotherapy. During the last follow-up, 57 (83.8%) aneurysms were completely occluded, whereas 6 (8.8%) and 2 (2.9%) aneurysms did and did not have a residual neck, respectively. Flow diversion was used to treat 13 patients, among whom 8 had total occlusion or stable residue. A total of 7 deaths (8.6%) were encountered in this series. ConclusionEndovascular treatment should be considered as the primary treatment modality for posterior circulation aneurysms. Despite the high morbidity and mortality rates, promising results can be achieved with correct patient selection. Flow diversion can be a feasible alternative for complex aneurysms that are difficult to treat.

The off-label uses of pipeline embolization device for complex cerebral aneurysms: Mid-term follow-up in a single center.

To describe the off-label uses of pipeline embolization device for a variety of types of aneurysms including ruptured aneurysms, posterior circulation aneurysms, small aneurysms, distal aneurysms, and recurrent aneurysms. Clinical and angiographic data of patients who underwent pipeline embolization device treatment on off-label use at our center were retrospectively reviewed. For categorical variables, Fisher's exact test was used, and a two-sample Wilcoxon rank-sum test was used for patients' age to analyze the correlation with outcomes. In this study, 121 aneurysms in 107 patients received off-label pipeline embolization device treatments. The overall rate of complete aneurysm occlusion was 77.8% (28/36 in 35 patients) for posterior circulation aneurysms and 95.3% (81/85 in 72 patients) for anterior circulation aneurysms. The posterior circulation aneurysms have a lower rate of aneurysm occlusion (p = 0.0372). The small aneurysms have a higher rate of aneurysm occlusion (p = 0.0104). The patient's sex, age, and aneurismal size were associated with ischemic stroke complications (p = 0.0397, 0.0166, and 0.0178). In posterior circulation aneurysm patients, only two basilar apex aneurysms underwent pipeline embolization device treatment, both of whom died of thrombotic complications. There was no difference in mortality between posterior circulation aneurysm patients (8.6%, 3/35) and anterior circulation aneurysm patients (1.4%, 1/72) (p = 0.1015). Patients of older age have a higher risk of death rate (p = 0.0053). The off-label use of pipeline embolization device is often performed in clinical practice and can achieve efficacy in complex aneurysms. The off-label use of pipeline embolization device was found to carry an increased rate of mortality in older patients. Excluding basilar apex aneurysms, the pipeline embolization device is as safe as anterior circulation aneurysms in the treatment of posterior circulation aneurysms elsewhere.

The Pipeline Embolization Device: a decade of lessons learned in the treatment of posterior circulation aneurysms in a multicenter cohort.

The Pipeline Embolization Device (PED) has prompted a paradigm shift in the approach to posterior circulation aneurysms. The year 2021 marks a decade since FDA approval of this flow diverter, and during this time operators have adapted to its off-label uses. The authors examined whether case selection, practice trends, and patient outcomes have changed over this 10-year period. This study is a retrospective review of consecutive posterior circulation aneurysms managed with the PED at four academic institutions in the US between January 1, 2011, and January 1, 2021. Factors related to case selection, rates of aneurysm occlusion, or complications were identified and evaluated. Angiographic outcomes as well as thromboembolic and hemorrhagic complications were investigated. This study included 117 patients (median age 60 years). At a median follow-up of 12 months, adequate occlusion (> 90%) was attained in 73.2% of aneurysms. Aneurysm occlusion rates were similar over the study interval. Thromboembolic and hemorrhagic complications were reported in 12.0% and 6.0% of the procedures, respectively. There was a nonsignificant trend toward a decline in the rate of thromboembolic (14.1% in 2011-2015 vs 9.4% in 2016-2021, p = 0.443) and hemorrhagic (9.4% in 2011-2015 vs 1.9% in 2016-2021, p = 0.089) complications. The authors observed a trend toward a decline in the rate of thromboembolic and hemorrhagic complications with improved operator experience in using the PED for posterior circulation aneurysms. The use of single-device PED flow diversion significantly increased, as did the tendency to treat smaller aneurysms and observe large unruptured fusiform/dolichoectatic lesions. These findings reflect changes attributable to evolving judgment with maturing experience in PED use.

Endovascular treatment of posterior circulation aneurysms: Results from a single-team experience of 81 cases including 13 flow diversion treatment

IntroductionRelatively constant surgical risks and rapid advances in endovascular treatment have caused a major shift toward endovascular management of posterior circulation aneurysms. This paper presents the results of a series of endovascularly treated posterior circulation aneurysms. MethodsA total of 81 patients who underwent endovascular treatment of posterior circulation aneurysms performed by a single team between 2009 and 2019 were included. Demographic, clinical, radiologic, and management details were retrospectively obtained from hospital records. ResultsAmong the included patients, 50 (61.7%) and 31 (38.3%) were female and male, respectively. Subarachnoid hemorrhage was observed in 30 patients (37%). Moreover, 40 (49.3%) aneurysms were treated with stent-assisted coiling, 1 (1.2%) aneurysm was treated with parent artery occlusion, 2 (2.4%) aneurysms were coiled using balloon assistance, 24 (29.6%) aneurysms were coiled primarily, 1 (1.2%) patient had an unsuccessful treatment attempt, and 13 (16.0%) aneurysms were treated with flow-diverter stents or stent monotherapy. During the last follow-up, 57 (83.8%) aneurysms were completely occluded, whereas 6 (8.8%) and 2 (2.9%) aneurysms did and did not have a residual neck, respectively. Flow diversion was used to treat 13 patients, among whom 8 had total occlusion or stable residue. A total of 7 deaths (8.6%) were encountered in this series. ConclusionEndovascular treatment should be considered as the primary treatment modality for posterior circulation aneurysms. Despite the high morbidity and mortality rates, promising results can be achieved with correct patient selection. Flow diversion can be a feasible alternative for complex aneurysms that are difficult to treat.

Posterior Circulation Aneurysms.

Posterior circulation aneurysms have a higher tendency to rupture and become symptomatic in comparison to anterior circulation aneurysms. Current treatment modalities for aneurysms in these locations vary widely including microsurgical clipping, trapping with bypass, wrapping, and various endovascular methods such as coiling, balloon or stent-assisted coiling, flow diversion, and vessel sacrifice, among others.Overall, surgical versus endovascular treatment of posterior circulation aneurysms continue to be a controversial topic in cerebrovascular neurosurgery. At our center, multi-disciplinary assessments including surgeons capable of both endovascular and microsurgical treatments of these aneurysms are employed to guide the treatment strategies. As advancements in both fields are made, this will continue to be a topic for debate. Anatomy and individual patient's characteristics will dictate the correct approach and therefore proficiency in the microsurgical techniques required to treat these aneurysms will continue to be both relevant and important.

Relationship between Transient Cortical Blindness and Contrast Medium Leakage That Occurs after Endovascular Treatment of Posterior Circulation Aneurysms.

The mechanism of transient cortical blindness after endovascular treatment-a rare phenomenon-has not been elucidated; however, it is assumed to be related to contrast medium leakage (CML). We investigated the relationship between postoperative CML and cortical blindness in patients who underwent endovascular treatment for vascular lesions of posterior circulation. This retrospective cohort study included 28 patients who underwent endovascular treatment for posterior circulation aneurysms at our hospital between January 2014 and December 2018. Cerebral CT was performed immediately after endovascular treatment and 24 h later. CT images were retrospectively evaluated with special interest in the presence and distribution of leakage of the contrast medium (CM). Patients were classified into the following three groups based on CT findings: Group A, no CML (11 patients); Group B, unilateral CML (5 patients); and Group C, bilateral CML (9 patients). The posterior circulation aneurysms were located in the basilar artery in 13 (52.0%) cases, in the posterior cerebral artery in 1 (4.0%) case, and in the vertebral artery in 11 (44.0%) cases. There was no difference regarding the adjunctive technique used for endovascular treatment between the groups. Patients in Group C used a significantly larger amount of CM than those in the other two groups. A longer operation time was associated with a larger amount of CM used during treatment. VerifyNow assay revealed that the P2Y12 reaction unit was significantly lower in Groups B and C. Cortical blindness was transiently observed in 2 of 9 patients (22.2%) in Group C, both of which showed CML surrounding the bilateral parieto-occipital sulcus. Both patients with cortical blindness showed bilateral CML, both of which showed CML surrounding the bilateral parieto-occipital sulcus. The CM-induced blood-brain barrier disruption may be the cause of cortical blindness.

Posterior Circulation Intervention but Mind the Spinal Cord!

AbstractSpinal cord infarction (SCI), a rare complication following endovascular treatment of posterior circulation aneurysms, is infrequently recognized in the periprocedural period. We illustrate the same with digital subtraction angiography and diffusion-weighted magnetic resonance imaging in this series of two cases. Categorically, the anterior spinal artery was patent, post-procedure, in both instances. Likely, guiding catheter-induced local flow alterations initiates the pathogenesis. A subsequent insufficiency of radiculomedullary artery (RMA) reinforcements is the probable mechanism leading to hemodynamic compromise. Our observations further reiterate that periprocedural antiplatelet therapy is conceivably ineffective in preventing SCI. Besides, advanced age and uncontrolled hypertension could potentially exacerbate the periprocedural RMA compromise. Due vigilance is required to recognize this rare and potentially life-threatening complication in posterior circulation neurovascular intervention.

Flow Diversion of Posterior Circulation Aneurysms: Systematic Review of Disaggregated Individual Patient Data.

Experience with endoluminal flow diversion for the treatment of posterior circulation aneurysms is limited. We sought to investigate factors associated with the safety and efficacy of this treatment by collecting disaggregated patient-level data from the literature. PubMed, EMBASE, and Ovid were searched up through 2019 for articles reporting flow diversion of posterior circulation aneurysms. Eighty-four studies reported disaggregated data for 301 separate posterior circulation aneurysms. Patient, aneurysm, and treatment factors were collected for each patient. Outcomes included the occurrence of major complications, angiographic occlusion, and functional outcomes based on the mRS. Significant differences in aneurysm and treatment characteristics were seen among different locations. Major complications occurred in 22%, angiographic occlusion was reported in 65% (11.3 months of mean follow-up), and good functional outcomes (mRS 0-2) were achieved in 67% (13.3 months of mean follow-up). Multivariate analysis identified age, number of flow diverters used, size, and prior treatment to be associated with outcome measures. Meta-analysis combining the current study with prior large nondisaggregated series of posterior circulation aneurysms treated with flow diversion found a pooled incidence of 20% (n = 712 patients) major complications and 75% (n = 581 patients) angiographic occlusions. This study design is susceptible to publication bias. Use of antiplatelet therapy was not uniformly reported. Endoluminal flow diversion is an important tool in the treatment of posterior circulation aneurysms. Patient age, aneurysm size, prior treatment, and the number of flow diverters used are important factors associated with complications and outcomes.

The utility of platelet inhibition testing in patients undergoing Pipeline embolization of intracranial aneurysms

BackgroundThe utility of using the VerifyNow P2Y12 platelet inhibition assay in patients undergoing Pipeline embolization of intracranial aneurysms remains controversial. As we have routinely employed the assay for patients undergoing...

Pivotal trial of the Neuroform Atlas stent for treatment of posterior circulation aneurysms: one-year outcomes

BackgroundStent-assisted coiling of wide-necked intracranial aneurysms (IAs) using the Neuroform Atlas Stent System (Atlas) has shown promising results.ObjectiveTo present the primary efficacy and safety results of the ATLAS Investigational Device...

Role of microsurgery for treatment of posterior circulation aneurysms in the endovascular era.

ObjectiveSeveral studies have reported that the outcomes of endovascular treatment were superior to those of microsurgical treatment for posterior circulation aneurysms. Thus, this study compared outcomes of endovascular and microsurgical treatment for posterior circulation aneurysms and assess the usefulness of microsurgery in these patients.MethodsOutcomes were retrospectively evaluated after endovascular and microsurgical treatment of 621 posterior circulation aneurysms. The 621 aneurysms included 187 treated by surgical clipping and 434 treated by endovascular coiling.ResultsIn patients with unruptured aneurysms the rates of residual lesions and retreatment were significantly lower in those who underwent microsurgical than endovascular treatment. However immediate postoperative and 6 month follow-up Glasgow outcome scale (GOS) scores did not differ significantly in the two groups. In patients with ruptured aneurysms, the rates of residual lesions and retreatment were significantly lower in the microsurgery than in the endovascular treatment group. Even so immediate postoperative and 6 month follow-up GOS scores did not differ significantly in the two groups.ConclusionsEndovascular treatment has increasingly become an alternative modality for microsurgery in posterior circulation aneurysm, whereas the indication for microsurgery is greatly reduced. However, the absolute number of microsurgery is maintained showing that it is a still valuable technique, as advances in endovascular or stent-assisted coiling have not solved many of the challenges inherent in the management of complex aneurysms. Hence, the advantages and limitations of both modalities must be carefully concerned in posterior circulation aneurysm to obtain favorable outcome.

Shared discussion of transradial approach complications may help broaden use

To the Editor: We read with interest the recently published article by Almallouhi et al .1 Truly, the transradial approach (TRA) for neuroendovascular procedures has taken the field by storm....

Expanding the Indications for Flow Diversion: Treatment of Posterior Circulation Aneurysms.

Posterior circulation aneurysms are often associated with a higher risk of rupture and compressive symptoms compared to their anterior circulation counterpart. Due to high morbidity and mortality associated with microsurgical treatment of those aneurysms, endovascular therapy gained ascendance as the preferred method of treatment. Flow diversion has emerged as a promising treatment option for posterior circulation aneurysms with a higher occlusion rate compared to other endovascular techniques and a lower complication rate compared to microsurgery. While treatment of saccular and dissecting aneurysms is often associated with comparatively good outcomes, fusiform and dolichoectatic aneurysms should be carefully selected prior to treatment to avoid devastating thromboembolic complications. Occlusion of covered posterior circulation branches showed no correlation with ischemic complications, and appropriate antiplatelet regimen and switching Clopidogrel nonresponders to different antiplatelet agents were associated with lower complication rates following flow diversion of posterior circulation aneurysms.

Commentary: Radial Artery Access for Treatment of Posterior Circulation Aneurysms Using the Pipeline Embolization Device: Case Series.

Commentary: Radial Artery Access for Treatment of Posterior Circulation Aneurysms Using the Pipeline Embolization Device: Case Series.

Radial Artery Access for Treatment of Posterior Circulation Aneurysms Using the Pipeline Embolization Device: Case Series.

The treatment of selected wide-neck and fusiform posterior circulation aneurysms is challenging for clipping as well as for endovascular route. To describe an endovascular approach for vertebral artery aneurysm treatment using transradial access (TRA) instead of the conventional transfemoral access. We collected cases from two institutions in which TRA was used for posterior circulation Pipeline Embolization Device (Medtronic, Dublin, Ireland) deployment. A total of four patients were treated. TRA was useful in the setting of extreme vessel tortuosity. We utilized 5F Terumo Glidesheath (Terumo Medical, Somerset, New Jersey), intermediate catheter, and a 027 microcatheter for Pipeline deployment. TRA was not associated with any access or deployment difficulties. Early experience suggests that TRA for Pipeline Embolization Device placement for posterior circulation aneurysm is a safe and efficient alternative to standard transfemoral access. While this approach was initially applied to patients with vascular anatomy that may not allow for safe femoral access or navigation, experience so far argues for considering a radial approach towards some posterior circulation aneurysm treatment.

Patency of Posterior Circulation Branches Covered by Flow Diverter Device: A Hemodynamic Study.

Objective: Flow diverter devices are increasingly used in the treatment of posterior circulation aneurysms, sometimes necessarily involving ostia of side branches and perforators. The aim of this study was to identify the hemodynamic influence of flow diverters on side branches and perforators of the posterior circulation.Methods: We performed a retrospective study of consecutive patients treated by a flow diverter device for posterior circulation aneurysms with anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA) involvement. Computational fluid dynamics (CFD) were used to discern hemodynamic changes of branches after deployment of the flow diverter.Results: We studied 18 branches from 17 patients (mean age, 50.72 ± 8.17 years). No branches were occluded on immediate angiography and later follow-up. Average flow velocity in aneurysms decreased from 0.077 ± 0.065 m/s to 0.025 ± 0.025 m/s (p < 0.01). Average flow velocity in branch ostia decreased from 0.29 ± 0.14 m/s to 0.27 ± 0.16 m/s (p = 0.189). The difference in flow velocity reduction ratio between aneurysms and branches was statistically significant (68.8 vs. 9.5%; p < 0.001). The mean pressure in branch ostia increased from 10,717.4 ± 489.0 to 10,859.0 ± 643.4 Pa (p < 0.01).Conclusion: While a flow diverter device is capable of slowing down aneurysmal inflow, it is unable to block the flow into branches and perforators when used in the treatment of posterior circulation aneurysms; flow velocity in branches even increased in some cases. With a low branch occlusion ratio, it may be acceptable to cover posterior circulation branches and perforators if unavoidable.

Pipeline Embolization of Vertebrobasilar Aneurysms—A Multicenter Case Series

The Pipeline Embolization Device (PED) has been increasingly used for the treatment of posterior circulation aneurysms. The purpose of the present study was to examine the clinical and angiographic outcomes of patients with vertebrobasilar aneurysms treated with the PED. We performed a retrospective review of vertebrobasilar aneurysms treated with the PED at 4 high-volume neurovascular centers. Patient, aneurysm, and procedural data were collected, including perioperative and delayed complications. Aneurysm occlusion on follow-up imaging studies was defined as complete (100%), near-complete (>90%), or incomplete (<90%) occlusion. The cohort included 35 patients with 37 vertebrobasilar aneurysms who underwent 36 treatment sessions. Of the 35 patients, 10 were men (29%), and the mean patient age was 54.1 years (range, 32-75). Eight patients (23%) underwent urgent treatment because of a ruptured aneurysm (n= 6), brainstem perforator stroke (n= 1), or post-traumatic pseudoaneurysm (n= 1). Of the 37 aneurysms, 22 arose from the vertebral artery (59%) and 15 from the basilar artery (41%). Also, 19 were saccular aneurysms (51%), with a mean size of 7.7 mm (range, 1.7-38.0); 17 were fusiform aneurysms (46%), with a mean size of 11.0 mm (range, 4.3-34); and 1 was a 2.9-mm blister aneurysm. The overall procedural complication rate was 14% (5 of 36), including 3 neurologically symptomatic complications. At a mean follow-up period of 14 months (range, 3-59), 24 of 34 aneurysms (71%) were completely occluded and 29 of 34 (85%) were completely or near-completely occluded. Our results show that Pipeline embolization of vertebrobasilar aneurysms is associated with acceptable occlusion and complication rates.

Morbidity and Mortality in Patients With Posterior Circulation Aneurysms Treated With the Pipeline Embolization Device: A Subgroup Analysis of the International Retrospective Study of the Pipeline Embolization Device.

The safety of PipelineTM Embolization Device (PED; Medtronic Inc, Dublin, Ireland) in posterior circulation aneurysms is still controversial. To study complications associated with the treatment of posterior circulation aneurysms by conducting a subgroup analysis from the International Retrospective Study of PED registry. Data from 91 consecutive patients with 95 posterior circulation aneurysms at 17 centers between July 2008 to February 2013 were analyzed. The primary endpoint was defined as any complication leading to neurological morbidity or death. The outcome predictors were calculated using Kaplan-Meier and Cox regression methods. The mean aneurysm size was 13.8 mm. Aneurysm types were saccular (36.8%), fusiform (29.5%), dissecting (28.4%), and others (5.3%). The median follow-up was 21.1 mo. Twelve (13.2%) patients encountered a primary endpoint event. In multivariate analysis for the primary endpoint, use of ≥3 PEDs and fusiform shape compared with other shapes had hazard ratios (HRs) of 7.77 (95% confidence interval [CI], 2.48-25.86; P = .0007) and 3.48 (95% CI, 1.06-13.39; P = .0488), respectively. The multivariate HR of aneurysm size for neurological morbidity after PED implantation was 1.11 (95% CI, 1.04-1.18; P = .0015), and HRs of ruptured aneurysm and age for neurological mortality were 8.1 (95% CI, 1.31-41.26; P = .0197) and 1.07 (95% CI, 1.02-1.15; P = .0262), respectively. Basilar artery aneurysm had an HR of 3.54 (95% CI, 1.12-14.18, P = .0529) in the univariate analysis for major outcomes. PED implantation may be considered for the treatment of posterior circulation aneurysms, especially of saccular or dissecting type. Our major complications appear to be comparable to those reported previously after clipping and coiling in the literature. Neurointerventionists should consider the shape, size, rupture, and location of complex posterior circulation aneurysms as well as age and PED number before the PED placement.