Experience With the Pipeline Embolization Device for Posterior Circulations Aneurysms: A Multicenter Cohort Study

Treatment of basilar artery aneurysms with two braided stents: Two centers experience of low-profile visualized intraluminal support stents versus Pipeline flow diverters

BACKGROUND

Both low-profile visualized intraluminal support (LVIS)stents and Pipeline flow diverters (FDs) are therapeutic strategies for basilar artery (BA) aneurysms, but they have not been directly compared.

METHODS

A total of 132 consecutive patients with 139 BA aneurysms treated with either LVIS stent or Pipeline FDs were analyzed. Propensity score matching (PSM) was used to control for age, sex, hypertension, aneurysm size, shape, location, and duration of follow-up. The treatment results of these two braided stents were compared.

RESULTS

LVIS stent was placed in 88 (63.3%) and Pipeline FDs in 51 (36.7%) procedures. Patients with Pipeline FDs tended to be younger and have less hypertension, whereas aneurysms had larger aneurysm size. After PSM, similar complete or near-complete occlusion rates (76.7% vs 73.3%, p = .766) and favorable functional outcomes (86.7% vs 90.0%, p = 1) were achieved in patients treated with LVIS stents and Pipeline FDs, respectively. Further comparisons were conducted at three different locations (basilar apex/basilar trunk/vertebrobasilar artery junction [VBJ]) separately, and the results showed a higher complete or near-complete aneurysm occlusion rate after Pipeline FD treatment than LVIS treatment (86.7% vs 59.2%, p = .012) only at VBJ, where a particularly high proportion of non-saccular shape (70.9%) and a male preponderance were noted.

CONCLUSION

Both braided stents were effective in the treatment of BA aneurysms, with good occlusion rates and favorable functional outcomes. Pipeline FD achieved a particularly higher aneurysm occlusion rate than LVIS stent at VBJ, where lesions often require reconstruction of the diseased vessel.

Endovascular Treatment of Basilar Apex Aneurysms: An Updated Systematic Review and Meta-Analysis in the Era of Flow Diversion

BACKGROUND

Endovascular options for the treatment of basilar apex aneurysms (BAAs) are heterogeneous, and evidence is limited to retrospective cohorts and case series. We seek to evaluate the efficacy and complications associated with various endovascular treatment methods of BAAs.

METHODS

Systematic review of PubMed, Embase, and Web of Science adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Retrospective and prospective studies evaluating endovascular treatment of BAAs between January 2010 and July 2024 were included. Relevant information including occlusion rates, aneurysm recurrence, retreatment rates, and complications were subjected to meta-analysis.

RESULTS

Fifteen studies with 1049 BAAs were included. The median aneurysm diameter was 8.5 mm (range, 4.6-19.75), with a median follow-up of 33.7 months (range, 6.0-117.6). Residual aneurysm filling occurred in 24% after primary coiling (95% CI = 0.16-0.32), 25% after single stent-assisted coiling (s-SAC; 95% CI = 0.04-0.46), 25% after Y-stents (95% CI = 0.12-0.37), and 23% after flow diverter stent (FDS; 95% CI = 0.11-0.35). Recurrence rates were high for primary coiling (27%, 95% CI = 0.18-0.36) and s-SAC (19%, 95% CI = 0.13-0.26), but significantly lower for Y-stents (9%, 95% CI = 0.03-0.15) and FDS (4%, 95% CI = -0.04-0.11). Retreatment rates were 19% for primary coiling (95% CI = 0.12-0.26), 17% for s-SAC (95% CI = 0.07-0.27), 5% for Y-stents (95% CI = -0.03-0.12), and 13% for FDS (95% CI = -0.01-0.27). Meta-regression indicated larger aneurysms had higher complication rates (P = 0.02). Thromboembolic events were most frequent with FDS and Y-stents(12%).

CONCLUSIONS

Occlusion rates were similar across treatments, but recurrence rates were significantly lower after Y-stents and FDS compared to primary coiling, although they carried a higher number of thromboembolic complications.

Clinical Outcomes On Tubridge Flow Diverter in Treatmenting Intracranial Aneurysms: a Retrospective Multicenter Registry Study

PURPOSE

In China, the application of nitinol Tubridge flow diverter (TFD) has become popular for treating intracranial aneurysms (IAs). In this study, we investigated the safety outcomes of the application of TFD for treating IAs in real-world scenarios.

METHODS

We retrospectively analyzed aneurysms treated with TFD in 235 centers throughout China between April 2018 and April 2020. The primary endpoint was the event-free survival rate at 12 months, defined as the occurrence of morbidity (spontaneous rupture, intraparenchymal hemorrhage (IPH), ischemic stroke, and permanent cranial neuropathy) or death. Univariate and multivariate analyses were performed to assess the risk factors. A good outcome was defined as a modified Rankin Score (mRS) of 0-2.

RESULTS

We included 1281 unruptured aneurysms treated with TFD. The overall neurological morbidity and death rates after 12 months were 5.4 and 2.8%, respectively. Ischemic strokes were the most common complication (4.2%, P < 0.001). Cranial neuropathy, IPH, and spontaneous rupture occurred in 0.3%, 0.3%, and 0.5% of aneurysms, respectively. Univariate and multivariate analyses indicated that the male gender, older age, larger aneurysm diameter, and aneurysm located on BA were the independent risk factors for neurologic events. Aneurysm located on BA was the independent risk factor for ischemic strokes. Most patients (1222) had access to the mRS, and 93.2% of them achieved good outcomes.

CONCLUSION

Treatment of IAs with TFD was associated with low morbidity and mortality, most of which were ischemic events. Large posterior aneurysms might be associated with a higher complication rate.

TRIAL REGISTRATION

Retrospectively registered.

Long-Term Safety and Efficacy of Pipeline Embolization Device in Anterior and Posterior Circulation Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Flow diversion using the pipeline embolization device (PED) has been a paradigm shift for anterior circulation (AC) aneurysms. However, only a few studies report the long-term (≥1 year) angiographic and clinical outcomes for posterior circulation (PC) aneurysms. This study aims to compare the long-term safety and efficacy of treatment of AC and PC aneurysms with PED.

METHODS

The databases included Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane, and Scopus. Studies with at least 10 patients and 1-year follow-up were included. Twenty-four studies met our inclusion criteria. A random effect meta-analysis was performed to estimate the ischemic and hemorrhagic complications. A meta-analysis of proportions was performed to estimate the pooled rates of long-term complete aneurysmal occlusion, symptomatic stroke, aneurysmal rupture, and intracranial hemorrhage.

RESULTS

There were 1952 aneurysms, of which 1547 (79.25%) were in the AC and 405 (20.75%) in the PC. The 1-year occlusion rate was 78% in AC compared to 73% in PC aneurysms (P < 0.01). The symptomatic infarct rate was 5% in AC compared to 13% in PC (P < 0.01). While the rupture rate was 1% in AC compared to 4% in PC (P = 0.01), the rate of intracranial hemorrhage was 2% for both (P = 0.99).

CONCLUSIONS

The long-term occlusion rate after PED was higher in AC aneurysms, and the cumulative incidence of stroke and aneurysm rupture was higher in PC aneurysms.

Pipeline embolization of complex, wide-necked middle cerebral artery bifurcation aneurysms: A single-center experience

PURPOSE

To evaluate the performance of Pipeline Embolization Device (PED) in complex, wide-necked middle cerebral artery (MCA) bifurcation aneurysms.

METHODS

We performed a retrospective review of patients treated with PED for complex, wide-necked MCA bifurcation aneurysms between August 2016 and March 2021. In addition to demographic data, we collected aneurysmal neck width, dome-to-neck ratio, complications, and clinical and angiographic follow-up. The embolization degree of aneurysms was evaluated by O'Kelly-Marotta (OKM) grading scale, and the prognosis was assessed with the modified Rankin Scale (mRS).

RESULTS

From August 2016 to March 2021, a total of 46 patients with 49 MCA bifurcation aneurysms in our center were enrolled, of whom all received PEDs successfully. The O'Kelly-Marotta (OKM) grading showed that post-procedure 15 patients (32.6%) were grade C, another 8 patients (17.4%) were grade D. Aneurysms with small remnant or complete occlusion were 50%, symptomatic ischemic events occurred in 3 (6.5%), and bleeding events in 1 (2.2%). 41 patients underwent a 6-month angiography follow-up, in which 7 patients (17.1%) remained OKM grade C and 30 patients (73.2%) achieved OKM grade D. Complete occlusion and small remnant aneurysms were up to 90.3%. 40 (97.6%) patients' mRS scores were 0, and 1 (2.4%) patient was 2. No new bleeding and ischemic events occurred during the 6-month.

CONCLUSIONS

The Pipeline Embolization Device provides a safe and effective treatment alternative for complex, wide-necked MCA aneurysms. A larger number with longer-term follow-up data is needed for further verification.

Safety and efficacy profile of off-label use of the Pipeline Embolization Device: A systematic review and meta-analysis

OBJECTIVE

The off-label utilization of the Pipeline Embolization Device (PED) is a common practice in numerous medical centers globally. Therefore, we conducted a systematic review and meta-analysis to evaluate the overall outcomes of this off-label usage of PEDs.

METHODS

PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to February 2023 using the Nested Knowledge platform to identify studies assessing the off-label use of PEDs. Any use of PED outside of the FDA-approved indication granted in 2018 is considered off-label use. Overall angiographic occlusion rates, ischemic and hemorrhagic complications, mortality, retreatment rates, and favorable clinic outcomes were included. Statistical analyses were performed to compare the overall outcome rates of anterior cerebral artery(ACA) vs. middle cerebral artery(MCA) and anterior vs posterior circulation subgroups.

RESULTS

We included 26 studies involving a total of 1,408 patients. The overall rate of complete occlusion was 80.3 % (95 % CI= 76.0-84.1). Subgroup analysis demonstrated a statistically significant difference in the rate of complete occlusion between anterior circulation (78.9 %) and posterior circulation (69.2 %) (p value=0.02). The rate of good clinical outcomes was 92.8 % (95 % CI= 88.8-95.4). The mortality rate was 1.4 % (95 % CI= 0.5-2.7). The overall rate of ischemic complications was 9.5 % (95 % CI= 7.7-11.6), with a comparable difference between anterior circulation (7.7 %) and posterior circulation (12.8 %) (p value=0.07). There was no statistically significant difference in MCA vs ACA subgroups in all parameters.

CONCLUSIONS

Off-label use of PEDs can be a safe and effective treatment option for intracranial aneurysms. However, there is a need for more prospective, high-quality, non-industry-funded registry studies and randomized trials to test the efficacy and safety of off-label usage of PEDs and to expand its indications.

Multiple telescoping flow diverter technique in endovascular treatment of a vertebrobasilar dissecting aneurysm: case report

A 64-year-old man presented with headache and dizziness. A vertebrobasilar dissecting aneurysm was identified via computed tomography angiography and high resolution magnetic resonance imaging. Perioperatively, standard oral dual antiplatelet drugs were given. Two flow diverters were telespcoped for endovascular treatment of the aneurysm. Postoperatively, there were no signs of cerebral infarction and no new symptoms. At the 6-month follow-up, digital subtraction angiography showed that the aneurysm was almost completely occluded, with no other complications. This case serves as a reference for using the multiple telescoping flow diverter technique to treat vertebrobasilar dissecting aneurysm.

Flow diversion for posterior circulation aneurysms: a multicenter retrospective study

Background

The prevalence of intracranial aneurysms is approximately 3% worldwide. Posterior circulation (PC) aneurysms have a higher risk of treatment complications than anterior circulation aneurysms. Improving the survival rate and quality of life of patients with PC aneurysms remains one of the most important issues in the field.

Objectives

Flow diverter (FD) treatment of PC aneurysms remains controversial. We aimed to investigate the effects of FD treatment and analyze differences among different application methods or aneurysm types in PC aneurysms.

Design

This is a multicenter retrospective study.

Methods

Patients with PC aneurysms treated with the pipeline embolization device (PED) or Tubridge embolization device (TED) between 2015 and 2020 in five neurovascular centers were retrospectively enrolled. The primary outcomes were major perioperative complication, clinical outcome, and aneurysm occlusion rates. Univariable and multivariable logistic regression analyses were used to determine the risk factors of each outcome.

Results

In total, 252 aneurysms were included. Major perioperative complication, favorable clinical outcome, and complete occlusion rates were 7.5%, 91.0%, and 79.1%, respectively. Compared with other types of aneurysms, dissecting aneurysms had the best clinical outcome and highest occlusion rate. Both clinical and angiographic outcomes were independently associated with the aneurysm location at the basilar artery. Aneurysm size was not associated with any outcome. TED had similar clinical and angiographic outcomes compared with PED but more perioperative major complications. Tandem treatment and coiling assistance may have poorer clinical outcomes but similar occlusion rates. Single- and multiple-stent treatments had similar outcomes.

Conclusion

FD treatment of PC aneurysms achieved favorable clinical outcomes and long-term aneurysm occlusion rates with acceptable perioperative complication rates, especially in dissecting and non-basilar artery aneurysms. There was no additional improvement in outcomes with coiling assistance, multi-stent application, or tandem treatment. Therefore, the use of PC aneurysms should be carefully considered.

Periprocedural cerebrovascular complications and 30-day outcomes of endovascular treatment for intracranial vertebral artery dissecting aneurysms

OBJECTIVE

The authors undertook an evaluation of periprocedural cerebrovascular complications and 30-day outcomes of endovascular treatment for intracranial vertebral artery dissecting aneurysms (IVADAs) and assessed the relevant risk factors.

METHODS

The authors included a series of 195 patients who had undergone endovascular treatment for 198 IVADAs. Clinical data, morphological characteristics, treatment details, and periprocedural cerebrovascular complications including intraprocedural rupture, intraprocedural thrombosis, intracranial hemorrhage (ICH), transient ischemic attack (TIA), and ischemic stroke (IS) were recorded. After evaluation of the 30-day modified Rankin Scale (mRS) scores, the authors applied univariate and multivariate logistic regression analyses to identify the risk factors for complications and 30-day unfavorable clinical outcomes.

RESULTS

There were no intraprocedural ruptures, but the authors recorded intraprocedural thrombosis (n = 5), ICH (n = 3), TIA (n = 1), and IS (n = 13), comprising an 11.1% (22/198) complication rate. Multivariate logistic regression analysis indicated that hyperlipidemia (odds ratio [OR] 3.17, 95% confidence interval [CI] 1.20-8.41, p = 0.020), IS history (OR 5.55, 95% CI 1.46-21.01, p = 0.012), and subarachnoid hemorrhage (SAH) (OR 4.48, 95% CI 1.52-13.20, p = 0.007) were risk factors for overall complications, whereas aneurysmal height (OR 0.77, 95% CI 0.61-0.98, p = 0.032) was a protective factor. SAH (OR 6.44, 95% CI 1.54-26.89, p = 0.011) and preprocedural mRS score > 2 (OR 5.07, 95% CI 1.01-25.59, p = 0.049) were independent risk factors for perforator occlusion stroke. Periprocedural cerebrovascular complications (OR 32.09, 95% CI 3.00-343.94, p = 0.004) and preprocedural mRS score > 2 (OR 319.92, 95% CI 30.28-3379.98, p < 0.001) were independent risk factors for 30-day unfavorable clinical outcomes.

CONCLUSIONS

Hyperlipidemia, IS history, and SAH were independent predictors for overall periprocedural cerebrovascular complications of endovascular treatment for IVADAs, but aneurysmal height was an independent protective factor. SAH and preprocedural mRS score > 2 were independent risk factors for perforator occlusion stroke. Preprocedural mRS score > 2 and periprocedural complications were independent risk factors for 30-day unfavorable clinical outcomes.

Pipeline Embolization Device for Small and Medium Vertebral Artery Aneurysms: A Multicenter Study

BACKGROUND

Pipeline embolization devices (PEDs) have been increasingly used for the treatment of posterior circulation aneurysms.

OBJECTIVE

To investigate the safety and efficacy of PED in the treatment of small to medium unruptured vertebral artery intracranial aneurysms (VAIAs).

METHODS

Data from 76 patients with 78 unruptured small and medium (≤12 mm) VAIAs were analyzed. Data for this study come from the PLUS study, which was conducted at 14 centers in China from 2014 to 2019. Univariate analyses were performed to evaluate predictors of the occlusion and complication.

RESULTS

Seventy-eight aneurysms in 76 patients were treated with PED. The mean aneurysm size was 8.28 ± 2.13 mm, and all PEDs were successfully placed. The median follow-up was 7 months and available for 67 (85.9%) aneurysms. Complete occlusion was seen in 60 (89.6%) aneurysms, which 86.6% met the primary efficacy outcome. All patients received clinical follow-up, the combined major morbidity and mortality was 2.6%, and 98.7% of patients had a good prognosis. Ischemic stroke occurred in 10.5% of patients, and adjuvant coil and successful after adjustment were predictors of ischemic stroke in the early postoperative and follow-up, respectively. There was no significant difference in the occlusion rate of aneurysm involving posterior inferior cerebellar artery ( P = .78). In cases where posterior inferior cerebellar artery was covered by PED, there was no significant difference in ischemic stroke.

CONCLUSION

In the treatment of unruptured ≤12 mm VAIAs, PED has a high surgical success rate, a high degree of occlusion, and low morbidity and mortality. PED may be a promising endovascular technique.

LVIS-within-enterprise double-stent technique with coil embolization in the treatment of patients with acutely ruptured intracranial vertebrobasilar artery-dissecting aneurysms

Objective

This study aimed to evaluate the feasibility of the low-profile visualized intraluminal support (LVIS)-within-enterprise double-stent technique for patients with acutely ruptured intracranial vertebrobasilar artery-dissecting aneurysms (ari-VBDAs).

Methods

A total of 30 patients with ari-VBDAs who underwent reconstructive treatment using LVIS-within-enterprise double-stent technique with coil embolization between January 2014 and May 2022 were retrospectively enrolled. Patients' characteristics and clinical and imaging outcomes were reviewed. The functional outcomes were assessed using the modified Rankin scale (mRS).

Results

A total of 34 ari-VBDAs were identified, including seven (20.6%) basilar artery aneurysms and 27 (79.4%) vertebral artery aneurysms. All aneurysms were successfully treated in the acute phase. In total, six (20.0%) patients experienced in-hospital serious adverse events, including two deaths (6.7%). The median clinical follow-up time of the remaining 28 patients was 20.0 (IQR, 7.3-40.8) months. The incidences of dependency or death (mRS score of 3-6) at discharge and at the last follow-up were 16.7% and 14.3%, respectively. Aneurysm rebleeding occurred in one (3.3%) patient periprocedurally. In total, three (10.0%) patients had ischemic events, one of which occurred during the periprocedural period and two occurred during follow-up. A total of two patients (6.7%) underwent ventriculoperitoneal shunt. Imaging follow-up was available for 14 patients at the median of 12.0 (IQR, 7.0-12.3) months, with a complete occlusion rate of 93.3% (14/15). In total, one patient experienced parent artery occlusion, and no aneurysm was recanalized.

Conclusion

LVIS-within-enterprise double-stent technique with coil embolization for the treatment of patients with ari-VBDAs could be performed with a good safety profile and high technical success rate. The rate of complete aneurysm occlusion during follow-up seemed to be satisfactory.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

The optimal management of ruptured basilar artery dissecting aneurysms: a case series and scoping review

The natural history of ruptured basilar artery dissecting aneurysms (BADAs) remains unclear compared to that of ruptured vertebral artery dissecting aneurysms (VADAs). In this study, we investigated the natural history and optimal management of ruptured BADAs. We identified 17 patients with ruptured BADA among 4586 patients with aneurysmal subarachnoid hemorrhage (SAH) treated in seven participating hospitals. A scoping literature review was undertaken to investigate prognostic factors. Six patients among the profiled patients (35.3%) died, all with poor SAH grades (World Federation of Neurological Societies Grade IV and V). Rebleeding after admission was observed in three patients (17.6%) with poor SAH grades. Aggressive treatment and conservative management were initiated in seven and ten patients, respectively. Patients with good SAH grades had significantly higher favorable treatment outcomes than those with poor grades (83.3% vs. 9.1%, P = 0.005). Moreover, based on a scoping review of 158 cases with ruptured BADA, including the patients from our series, approximately 90% of patients with good SAH grades had favorable outcomes. A good SAH grade and no rebleeding after admission were favorable prognostic factors (P < 0.0001 and P = 0.002, respectively). The rebleeding rates were 20.2%, 13.3%, and 6.3% for dilated, pearl and string, and stenotic lesions, respectively. We concluded that the natural history of isolated ruptured BADAs may be better than that of VADAs. Although definitive treatment, if possible, is undoubtedly important, conservative management with careful radiological follow-up for morphological changes might be a viable option for patients in good clinical condition and with non-dilated lesions.

Use of flow diverter device in basilar artery for aneurysm treatment: Case series and literature review

Background

Flow diverters (FDs) for the treatment of basilar artery (BA) aneurysms remain controversial. In this study, we report our initial experience of flow diversion for treatment of this pathology.

Methods

Consecutive patients with an aneurysm of the BA that was treated by implantation of the FD were included in our retrospective study. Procedural complications, aneurysm occlusion, and a functional outcome were evaluated. FD placement in BA for aneurysm treatment reported in the literature was also reviewed and summarized.

Results

Sixteen patients with 16 BA aneurysms were treated by FD implantation with (n = 8) or without (n = 8) adjunctive coiling. The Tubridge was used in 13 (81.3%) and Pipeline in 3 (18.8%) procedures. Average aneurysm size was 15.7 mm. Four aneurysms were located at the basilar apex, six at the basilar trunk, and six at the vertebrobasilar junction. Three patients experienced procedural complications (18.8%), including two ischemic strokes and one hydrocephalus, with resultant mortality in one case (6.3%). Median follow-up was 7.7 months and available for 15 aneurysms. Complete/near-complete occlusion was seen in 13 (86.7%) aneurysms.

Conclusion

In our initial experience, flow diversion is feasible and safe in the treatment of BA aneurysms with promising occlusion rates at mid-term follow-up. Larger cohort studies are required to validate these results.

Anterior Circulation Fusiform Aneurysms Have a Lower Occlusion Rate After Pipeline Embolization Device Treatment Than Posterior Circulation Fusiform Aneurysms: A Multicenter Cohort Study

Objective:

Intracranial fusiform aneurysms are uncommon and can occur in vessels of the anterior circulation (AC) or posterior circulation (PC). While flow diversion is one treatment option, research into Pipeline Embolization Device (PED) treatment is lacking. This study explored the efficacy and safety of PED treatment for intracranial fusiform aneurysms, and compared therapeutic effects between AC and PC aneurysms.

Methods

In the post-market multi-center cohort study of embolization of intracranial aneurysms with PED in China (PLUS) registry study, we retrospectively analyzed 71 fusiform aneurysms in 67 patients among 1,171 patients treated with a PED from November 2014 to October 2019. The general characteristics, perioperative status, aneurysm occlusion rate at the last follow-up angiography, and changes in modified Rankin Scale scores were analyzed. Aneurysms were divided into AC and PC groups, and univariate and multivariate analyses were conducted.

Results

The study included 26 AC (25 patients) and 45 PC (42 patients) aneurysms. A total of 75 PEDs were used, an average of 1.1 PEDs were used, and the median follow-up was 6.7 months. Fifty aneurysms (71.4%) were occluded and twenty (28.5%) were incompletely occluded. There were significantly more occluded aneurysms in the PC group than in the AC group (12 vs. 38; P = 0.001). Risk factors for incomplete occlusion were AC aneurysms (P = 0.001) and a perforating artery originating from the aneurysm (P = 0.006). The mean modified Rankin Scale score was significantly lower at the last follow up than preoperatively (0.58 vs. 0.21; P = 0.0001).

Conclusion

Non-overlapping PED is a safe and effective treatment for both AC and PC fusiform aneurysms. The occlusion rate of AC fusiform aneurysms is lower than that of PC.

Vertebral artery V3 portion-radial artery-distal common carotid artery (V3-RA-dCCA) bypass for large basilar trunk aneurysm with bilateral proximal common carotid artery occlusion-technical note

BACKGROUND

Large basilar trunk aneurysm caused by bilateral occlusion of the proximal common carotid artery is rare. We treated one case with vertebral V3 portion-radial artery-distal common carotid artery (V3-RA-dCCA) bypass.

CASE DESCRIPTION

Basilar trunk aneurysm and bilateral occlusion of the proximal CCA were found incidentally in a 70-year-old woman. During the next 5 years, the aneurysm gradually enlarged to 12 mm, and blood flow of the anterior circulation was supplied through the posterior communicating artery. V3-RA-dCCA bypass was performed to reduce the stress of blood flow and prevent aneurysm growth and rupture. After exposing the neck portion, forearm of RA, and V3 portion of the vertebral artery, we created a space just below the sternocleidomastoid muscle to bypass the RA. We flushed the RA with albumin to stiffen the artery and temporarily clamped the bilateral sides of the RA to prevent twisting. We anastomosed the V3 and RA with a 9-0 thread and temporarily clamped the V3. After flushing the RA with albumin to prevent twisting, we clamped the external and internal carotid arteries, opened the dCCA with a vascular punch to prevent arterial dissection, and anastomosed the RA to the dCCA. The patency of the bypass was confirmed with Doppler and indocyanine green video angiography. The postoperative course was uneventful, bypass patency was good, and the aneurysm did not expand further.

CONCLUSION

V3-RA-dCCA bypass may be an effective and low-risk treatment for large basilar trunk aneurysms with bilateral occlusion of the proximal common carotid artery.

Endovascular Treatment of Large or Giant Basilar Artery Aneurysms Using the Pipeline Embolization Device: Complications and Outcomes

Background

This study aimed to investigate clinical and angiographic outcomes of Pipeline embolization device (PED) treatment of large or giant basilar artery (BA) aneurysms and examine associated factors.

Methods

Clinical and angiographic data of 29 patients (18 men, 11 women) with large or giant BA aneurysms were retrospectively examined. Mean age was 44.1 ± 21.2 years (range, 30–68). Mean aneurysm size was 22.2 ± 8.3 mm (range, 12.0–40.1).

Results

Mean angiographic follow-up was 18.3 ± 3.4 months (range, 4.5–60). The rate of adequate aneurysmal occlusion (O'Kelly–Marotta grade C–D) was 87%. The overall complication rate was 44.8%; most complications (84.6%) occurred in the periprocedural period. Univariable comparison of patients who did and did not develop complications showed significant differences in aneurysm size (p < 0.01), intra-aneurysmal thrombus (p = 0.03), and mean number of PEDs used (p = 0.02). Aneurysm size (odds ratio, 1.4; p = 0.04) was an independent risk factor for periprocedural complications in multivariable analysis. Mean clinical follow-up was 23.5 ± 3.2 months (range, 0.1–65). Nine patients (31%) had a poor clinical outcome (modified Rankin scale score ≥3) at last follow-up, including 7 patients who died. Univariable comparisons between patients with favorable and unfavorable clinical outcomes showed that aneurysm size (p = 0.009) and intra-aneurysmal thrombus (p = 0.04) significantly differed between the groups. Multivariable analysis showed that aneurysm size (odds ratio, 1.1; p = 0.04) was an independent risk factor for poor clinical outcome.

Conclusion

PED treatment of large or giant BA aneurysms is effective and can achieve a satisfactory long-term occlusion rate. However, the treatment complications are not negligible. Aneurysm size is the strongest predictor of perioperative complications and poor clinical outcome.

Vertebral artery dissection and associated ruptured intracranial pseudoaneurysm successfully treated with coil assisted flow diversion: A case report and review of the literature

Dissecting intracranial pseudoaneurysms (IPs) are associated with a high incidence of rupture and poor neurologic outcomes. Lesions in the posterior circulation are particularly malignant and pose even greater management challenges. Traditional management consists of microsurgical vessel sacrifice with or without bypass. Flow diversion (FD) in the setting of subarachnoid hemorrhage (SAH) represents a reconstructive treatment option and can be paired with coil embolization to promote more rapid thrombosis of the lesion. We report a case of a ruptured dissecting vertebral artery (VA) IP successfully acutely treated with coil-assisted FD. A 53-year-old male presented with a right V4 dissection spanning the origin of the posterior inferior cerebellar artery and associated ruptured V4 IP. The patient was treated with coil-assisted FD. Oral dual-antiplatelet therapy (DAPT) was initiated during the procedure, and intravenous tirofiban was used as a bridging agent. Immediate obliteration of the IP was achieved, with near-complete resolution of the dissection within 48 h. The patient made a complete recovery, and angiography at 6 weeks confirmed total IP obliteration, reconstruction of the VA, and a patent stent. The use of FD and DAPT in the setting of acute SAH remains controversial. We believe that coil-assisted FD in carefully selected patients offers significant advantages over traditional microsurgical and endovascular options. The risks posed by DAPT and potential for delayed thrombosis with FD can be effectively mitigated with planning and the development of protocols. We discuss the current literature in the context of our case and review the challenges associated with treating these often devastating lesions.

Flow diverters for the posterior inferior cerebellar artery aneurysms: A systematic review and a single-arm meta-analysis

BACKGROUND

The treatment of posterior inferior cerebellar artery aneurysms is controversial. Recently, flow diverters have emerged as an attractive treatment option. Here, we performed a systematic review and meta-analysis of the angiographic and clinical outcomes of flow diverter-treated posterior inferior cerebellar artery aneurysms.

METHODS

We searched the PubMed, EMBASE and Web of Science databases for studies published from inception to January 2021. We included studies that described flow diverters procedures for posterior inferior cerebellar artery aneurysms with ≥2 patients. The outcomes were the complete occlusion rate and flow diverter-related complication rate. Meta-analysis was performed using a random or fixed effects model based on heterogeneity.

RESULTS

We included six studies involving 46 posterior inferior cerebellar artery aneurysms. There were 14 ruptured aneurysms. All flow diverters were successfully released and the technical success rate was 100%. The complete occlusion rate was 81% (95% confidence interval = 65-93%; I² = 0.00%; P < 0.01). The flow diverter-related complication rate was 18% (95% confidence interval = 5-36%; I² = 0.00%; P < 0.01). One patient died of rebleeding. The mortality rate was <1% (95% confidence interval = -1-1%; I² = 0.00%; P = 0.951).

CONCLUSIONS

Treatment of posterior inferior cerebellar artery aneurysms with flow diverters is feasible and carries a high degree of technical success. However, this treatment is underutilized in patients with posterior inferior cerebellar artery aneurysms due to a higher complication rate and lower occlusion rate compared with clipping and traditional endovascular treatment. Further well-designed prospective and randomized studies are required to fully understand the effects of flow diverters especially in posterior inferior cerebellar artery aneurysms patients requiring endovascular treatment.

Pipeline Embolization Devices for the Treatment of Intracranial Aneurysms, Single-Center Registry: Long-Term Angiographic and Clinical Outcomes from 1000 Aneurysms

BACKGROUND

Prospective studies have established the safety and efficacy of the PipelineTM Embolization Device (PED; Medtronic) for treatment of intracranial aneurysms (IA).

OBJECTIVE

To investigate long-term outcomes from the Pipeline Embolization Devices for the Treatment of Intracranial Aneurysms (PEDESTRIAN) Registry.

METHODS

The PEDESTRIAN Registry data were retrospectively reviewed, which included patients (March 2006 to July 2019) with complex IAs treated with PED. Patients with unfavorable anatomy and/or recurrence following previous treatment were included and excluded those with acute subarachnoid hemorrhage. The primary angiographic endpoint was complete occlusion and long-term stability. Clinical and radiological follow-up was performed at 3 to 6 mo, 12 mo, and yearly thereafter.

RESULTS

A total of 835 patients (mean age 55.9 ± 14.7 yr; 80.0% female) with 1000 aneurysms were included. Aneurysms varied in size: 64.6% were small (≤10 mm), 25.6% were large (11-24 mm), and 9.8% were giant (≥25 mm). A total of 1214 PEDs were deployed. Follow-up angiography was available for 85.1% of patients with 776 aneurysms at 24.6 ± 25.0 mo (mean). Complete occlusion was demonstrated in 75.8% of aneurysms at 12 mo, 92.9% at 2 to 4 yr, and 96.4% at >5 yr. During the postprocedural period, modified Rankin Scale scores remained stable or improved in 96.2% of patients, with stability or improvement in 99.1% of patients >5 yr. The overall major morbidity and neurological mortality rate was 5.8%.

CONCLUSION

This study demonstrated high rates of long-term complete aneurysm occlusion, stable or improved functional outcomes, and low rates of complications and mortality. Clinical and angiographic outcomes improved over long-term follow-up, demonstrating that endovascular treatment of IA with PED is safe and effective.

Comparison of clinical and histopathological characteristics of short-term progressive and non-progressive blood blister-like aneurysms

BACKGROUND

Many blood blister aneurysms (BBAs) have been documented with a rapid progression history in repeated angiography. The underlying mechanism and clinical significance remained elusive. This current study aims to clarify the clinical and histopathological differences between short-term progressive BBA and non-progressive BBAs.

METHODS AND MATERIALS

Eighty-one patients with BBAs were consecutively included for this single-center retrospective analysis. Clinical and radiological data on these patients were retrieved from 2017 to 2019. BBAs were defined as either progressive or non-progressive based on observed growth based on repeated imaging. Histopathological examinations of a saccular aneurysm, a progressive BBA, and a non-progressive BBA were conducted using representative aneurysm samples.

RESULTS

Among all enrolled patients, 26 of the them were identified with progressive BBAs, while the other 55 with non-progressive BBAs. Progressive BBAs were diagnosed significantly earlier in angiography (3.36 ± 0.61 vs. 6.53 ± 1.31 days, p < 0.05) and showed a higher presence rate of daughter sacs (61.5 vs. 38.2%, p < 0.05). Three different progression patterns were identified. BBAs that developed daughter sac enlargement are diagnosed significantly later than BBAs exhibiting other progression patterns. Patients with progressive and non-progressive BBAs exhibited similar overall clinical outcomes and incidence for complications. For patients with non-progressive BBAs, microsurgery appears to be inferior to endovascular treatment, while for patients with progressive BBAs, the short-term outcomes between microsurgery and endovascular treatment were identical. Histopathological analysis revealed that both subtypes shared a similar pseudoaneurysms structure, but non-progressive BBAs had more histologically destructed aneurysm wall with less remnant fibrillar collagen in adventitia.

CONCLUSIONS

Progressive and non-progressive BBAs may not be distinct pathological lesions but represent different stages during the BBA development. Early intervention, regardless of treatment methods, is recommended for salvageable patients with progressive BBAs, but microsurgery should be performed with caution for non-progressive BBAs due to increased surgical risk.