Stent-Assisted Coil Embolization of Vertebrobasilar Dissecting Aneurysms: Procedural Outcomes and Factors for Recanalization

Flow alteration surgery using a radial artery graft for recurrent ruptured vertebral artery dissecting aneurysm after stent-assisted coil embolization: A case report

BACKGROUND

Ruptured vertebral artery dissecting aneurysm (VADA) is often treated surgically with coil embolization and sometimes recurs. We herein report a case of recurrent ruptured VADA after stent-assisted coil embolization (SAC) that was successfully treated with flow alteration surgery using a radial artery (RA) graft.

CASE DESCRIPTION

A 67-year-old woman presented with headache and coma. Enhanced CT revealed subarachnoid hemorrhage due to right VADA. Since the left VA was hypoplastic, the aneurysm was treated with SAC. However, follow-up angiography revealed recurrence of the aneurysm. Additional embolization was not considered due to the small size of the recurrent lesion and the presence of a stent; therefore, flow alteration surgery was performed using a RA graft. There were no neurological deficits after surgery or recurrence.

CONCLUSION

Flow alteration surgery using a RA graft is useful for recurrent VADA after SAC.

Stent-Assisted Coil Embolization Versus Flow-Diverting Stent in Unruptured Vertebral Artery Dissecting Aneurysms: Efficacy and Safety Comparison

BACKGROUND

Reconstructive strategies for unruptured vertebral artery dissecting aneurysms (VADAs) have increasingly relied on newly developed endovascular devices. However, their clinical performance metrics are seldom reported.

OBJECTIVE

To compare stent-assisted coil embolization (SACE) and flow-diverting stent (FDS) deployment as treatments for unruptured VADAs, focusing on efficacy and safety.

METHODS

A total of 72 VADAs were submitted to SACE (n = 48) or FDS (n = 24) between April 2009 and September 2021. We reviewed medical records and radiological data to assess efficacy and safety outcomes by method, building an inverse probability of treatment-weighted (IPTW) logistic regression model and conducting survival analyses.

RESULTS

Ultimately, 24 aneurysms (33.3%) showed signs of recanalization (major, 14; minor, 10) at 6-month follow-up. Initially determined 6-month rates of overall (SACE, 31.2%; FDS, 41.7%) and major (SACE, 20.8%; FDS, 16.7%) recanalization did not differ significantly by modality; but in the IPTW logistic regression model, adjusted for aneurysm morphology, major recanalization at 6 months was lower for the FDS (vs SACE) subset (odds ratio = 0.196; P = .027). Likewise, the cumulative rate of major recanalization was more favorable for the FDS (vs SACE) subset (hazard ratio = 0.291; P = .048) in IPTW Cox proportional hazards model adjusted for aneurysm morphology. Modality-based assessments of procedural and delayed complications were similar.

CONCLUSION

Both reconstructive VADA interventions are safe and effective by adjusting treatment modality depending on the angioanatomic configuration. However, follow-up data after treatment proved more favorable for FDS deployment than for SACE in limiting major recanalization. Case-controlled studies of more sizeable cohorts are needed for corroboration.

Predictive Factors of Recurrence after Endovascular Treatment of Unruptured Vertebrobasilar Fusiform Aneurysms

PURPOSE

This study aimed to investigate the predictive factors of recurrence after endovascular treatment (EVT) for unruptured vertebrobasilar fusiform aneurysms (VBFA).

METHODS

This single-center retrospective study evaluated 36 patients who underwent EVT of unruptured VBFA between 2008 and 2020. Variables influencing recurrence, such as size, type, thrombus, preoperative symptoms, and treatment methods, were analyzed. All patients were followed up using vessel imaging.

RESULTS

In total, 7 of 36 patients (19.4%) developed recurrence. The mean time from EVT to recurrence was 9.2 months (range 2-26.9 months). Maximum aneurysmal diameter on magnetic resonance imaging was decreased, increased, and remained unchanged in 1, 7, and 28 patients, respectively. Transitional type VBFA, brain compression symptoms, large aneurysmal diameter and length, preoperative modified Rankin Scale (mRS) score ≥ 2, sole stenting technique, and intra-aneurysmal thrombus significantly influenced the risk of recurrence. Post-EVT, 7 (19.4%) patients showed complete occlusion of the aneurysm on the immediate postoperative angiogram, and 22 (61.1%) patients showed complete occlusion on the 1‑year follow-up imaging. Good outcomes were observed in 32 patients (88.9%) at the last follow-up, with a mRS score of 0-1 after EVT.

CONCLUSION

EVT achieves good outcomes in unruptured VBFA. Transitional type VBFA, brain compression symptoms, large aneurysmal diameter and length, preoperative mRS score ≥ 2, sole stenting technique, and intra-aneurysmal thrombus are risk factors for aneurysm recurrence after EVT.

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.

Outcomes of reconstructive endovascular treatment of vertebrobasilar dissecting aneurysms with intramural hematoma

Background

Vertebrobasilar dissecting aneurysms (VBDAs) with an intramural hematoma (IMH) usually cause symptoms because of mass effect and grow in size over time. Clinical outcomes are generally poor.

Objective

This study aimed to examine outcomes of reconstructive endovascular treatment (EVT) in patients with VBDAs with IMH. Safety and effectiveness were compared between flow diverters (FDs) and conventional stents.

Methods

We retrospectively analyzed the clinical and radiological data of 36 VBDAs with IMH in 36 patients who underwent EVT with either FDs or conventional stents from January 2012 to December 2020 at our institution.

Results

Among the 36 study patients, 20 were treated with FDs and 16 with conventional stents. Incidence of procedure-related complications did not significantly differ between the two stents. IMH growth occurred after EVT in a significantly higher proportion of conventional stent group aneurysms (zero vs. 31.3% [5/16]; p = 0.012). Among the five aneurysms with IMHs that grew, all recurred. Change in IMH size after EVT was significantly lower in the FD group (−2.7 vs. +8.1%, p = 0.036). However, after the recurrent aneurysms were removed from the conventional stent group, change in IMH size did not significantly differ between the two groups (−2.7 vs. +1.0%, p = 0.332). The proportion of patients who experienced an improvement in mRS score after EVT was significantly higher in the FD group (60 vs. 25%, p = 0.036).

Conclusion

IMHs in VBDAs stop growing after successful reconstructive EVT. Although both FD and conventional stent treatment are effective, FD treatment may be superior based on clinical outcomes and effect on IMH size.

Flow Diverter in Unruptured Intracranial Vertebral Artery Dissecting Aneurysm

Objective

Intracranial vertebral artery dissecting aneurysm (VADA) may present as aneurysmal dilation alone, dilation with coexisting stenosis, or, in some cases, as a recurrent aneurysm after previous reconstructive treatment. To date, the clinical utility of flow diverters in VADA has not been examined according to these various circumstances. This study aims to report the safety and efficacy of flow diverters in the treatment of various manifestations of intracranial VADA.

Methods

A total of 26 patients and 27 VADAs treated with flow diverting stents from November 2014 to September 2021 were included. Medical records and radiologic data were analyzed to assess the safety and efficacy of flow diverting stents.

Results

The results showed that 12 cases (44.4%) presented with aneurysmal dilation only, 7 (26.0%) with aneurysmal dilation and one or more associated stenotic lesions, and 8 (29.6%) as recurrence after previous treatment, including stent-assisted coil embolization (n = 5), single stent only (n = 1), and coil embolization without stent (n = 2). Among 27 lesions, 25 were treated with single flow diverters; additional flow diverting stents were required in 2 cases because of incomplete coverage of the aneurysm neck. There was one instance of incomplete expansion of the flow diverter. All cases showed contrast stagnation in the aneurysmal sac immediately after deployment of the flow diverting stent, and during a mean follow-up period of 18.6 months (range 6 to 60), the overall complete occlusion rate was 55.6%, with complete occlusion of 83.3% of aneurysmal dilation only lesions, 42.9% of aneurysms with stenosis, and 25% of the recurrent aneurysm. Only two patients (7.7%) had delayed ischemic complications.

Conclusion

Flow diverters have proven safe and effective in unruptured VADA. However, the complete occlusion rate with the flow diverter is relatively lower in VADA with stenosis or with previous stent placement than in dilation-only lesions. Further study with a larger cohort would be needed to confirm these results.

Flow diverter for the treatment of large (> 10 mm) vertebral artery dissecting aneurysms

OBJECTIVE

To evaluate the outcomes of flow-diverting device (FDD) treatment for large vertebral artery dissecting aneurysms (VADAs).

METHODS

This retrospective study evaluated 12 patients with 12 VADAs who were treated using FDD between 2013 and 2020. Clinical and radiographic data, including procedure-related complications and clinical outcomes assessed using the modified Rankin Scale (mRS) at the time of the last follow-up, were collected and reviewed.

RESULTS

All 12 patients had unruptured aneurysms. There were 3 (25%) female and 9 (75%) male patients, and the mean patient age was 54.6 years. The mean size of the aneurysm was 15.9 ± 4.8 mm. The mean follow-up duration was 15.8 months. Single FDD without additional coils was used in all patients. One patient underwent second-line treatment with FDD for recurrence of large VADA after stent-assisted coiling. Immediate follow-up angiography after placement of the FDD demonstrated intra-aneurysmal contrast stasis. There were 2 (17%) patients who had peri-procedural stroke. Angiography at the 6-month follow-up in 10 patients showed favorable occlusion (OKM grade C3 + D). A total of 11 (92%) patients had good clinical outcome (modified Rankin Scale ≤ 2) at the last follow-up. No re-treatment or delayed aneurysm rupture occurred during the follow-up period.

CONCLUSIONS

Reconstructive technique with FDD is a feasible and effective modality for the treatment of large VADAs, showing favorable occlusion rate and clinical outcome.

LVIS-within-enterprise double-stent procedure without coiling beneficial as treatment of unruptured vertebral artery dissecting aneurysms

Stenting of vertebral artery dissecting aneurysms (VADAs) may promote mural apposition of intimal flaps, preserving the patency of injured vessels. Moreover, stent deployment may serve to alter intra-aneurysm flow, inducing saccular thrombus formation, neointimal development, and remodeling of injured vessels. Although an overlapping multistent strategy with coiling has proven successful in this setting, yielding good anatomic and clinical outcomes, coiling may be technically infeasible in some VADAs with unfavorably configured circumferential elevations. Herein, we describe three patients with VADAs for whom coiling was deemed technically problematic. Each underwent double stenting (LVIS within Enterprise), without coil insertion, using local anesthesia. Conventional angiographic follow-up regularly disclosed excellent saccular occlusion and subsequent remodeling of stented arteries. LVIS-within-Enterprise double stenting may be of particular benefit in patients with VADAs, the Enterprise providing outer support to minimize stent bulging (as a fusiform aneurysm) as the inner LVIS reinforces flow diversion.

Overlapping stent-assisted coil embolization for vertebrobasilar dissecting aneurysms: a single-center study

Effective treatment strategies for vertebrobasilar dissecting aneurysms (VBDAs) remain controversial due to their high morbidity and mortality. The aim of the present study was to evaluate the efficacy of overlapping stent-assisted coil embolization (OSCE) in VBDA patients. A total of 42 patients with VBDA were retrospectively examined by OSCE from May 2015 to August 2019. Patients' clinical and radiological parameters were assessed at discharge and during interim follow-up. Safety, technical feasibility and follow-up clinical and imaging observations for therapy were also evaluated retrospectively. The average age of the 42 patients who underwent OSCE was 54 years (range 33 to 74 years). Overlapping stents were successfully implanted in all patients after coil embolism. Overall clinical results were effective (score on a modified Rankin scale from 0 to 2) in all patients. In the meantime, all patients had favorable outcomes when evaluating telephone calls or digital subtractive angiography (DSA) imaging. Among 42 patients, one patient died due to a perioperative rupture. All the remaining 41 patients had a good prognosis during the follow-up telephone call, with a median follow-up of 28 months (range, 2 to 55 months). The total number of DSA recurrences was 20. Subsequent DSA results showed that all aneurysms were completely occluded while in only one case the parent artery of the aneurysm was completely closed. OSCE in VBDAs patients is safe and effective. This technique showed favorable results in clinical and imaging follow-ups for non-ruptured and ruptured VBDAs.

Modified Balloon-in-Stent Technique for Circumferential Vertebral Artery Dissecting Aneurysm

BACKGROUND

Treatment for circumferential vertebral artery dissecting aneurysms (VADAs) remains challenging. Stent-assisted coil embolization is the most common treatment technique. However, this approach presents high rates of incomplete occlusion and recurrence, often requiring the addition of second or third stents for reconstruction. A flow diverter may achieve favorable clinical outcomes, but it cannot result in immediate aneurysm occlusion and is limited by strict antiplatelets and expensive price. We report excellent results of a 1-stage modified balloon-in-stent technique for circumferential VADA.

METHODS

A total of 12 patients were treated with the modified balloon-in-stent technique for VADAs. A homogeneous coil was used to fill the aneurysm sac, followed by deployment of 1 self-expandable stent and in-stent Scepter balloon angioplasty. Clinical presentations, outcomes, and imaging results were evaluated over at least 2 years of follow-up.

RESULTS

Our 12 patients were examined during a mean follow-up period of 36.2 months (range, 2-5 years). The initial symptoms presented included subarachnoid hemorrhage (5 of 12; 41.7%), ischemia (3 of 12; 25.0%), and nonischemia (4 of 12; 33.3%). The modified BIS technique and coil embolization were successful in all patients. No technique-related complications or recanalization occurred during follow-up.

CONCLUSIONS

We demonstrated an innovative modified BIS technique to treat circumferential VADA by using a coiling basket followed by the deployment of a self-expandable stent and in-stent Scepter balloon angioplasty. This strategy is safe, feasible, and cost effective and was not associated with recurrence or complications over at least 2 years of follow-up.

Treatment of posterior circulation non-saccular aneurysms with flow diversion versus stent-assisted coiling: a systematic review and meta-analysis

Treatment of non-saccular aneurysms of the posterior circulation poses a great challenge with unpredictable outcomes due to the absence of a true aneurysm neck and the presence of perforating vessels. In this article, we aim to compare endovascular treatment of unruptured posterior circulation non-saccular aneurysms with stent-assisted coiling (SAC) and flow diversion (FD) in terms of occlusion rate and clinical outcomes. A systematic search of electronic databases from inception to August 2019 identified 484 articles for screening. After proper inclusion/exclusion criteria, 15 articles were included and data were extracted and analyzed using meta-analysis of proportions. The pooled cohort consisted of 430 aneurysms: 128 (29.7%) treated with SAC in 5 studies and 302 (70.3%) treated with FD in 11 studies. Complete/near-complete occlusion was achieved in 83% after FD (95% CI 0.75 to 0.90; I²=45%) and 84% after SAC (95% CI 0.72 to 0.91; I²=22%), with no significant difference between techniques (p=0.95). Periprocedural complications were observed in 18% after FD (95% CI 0.14 to 0.23; I²=0%) and 6% after SAC (95% CI 0.02 to 0.13; I²=0%); the subgroup analysis was statistically significant (p=0.008). Furthermore, no statistically significant difference was observed in favorable clinical outcomes between groups. These results suggest similar efficacy in occlusion rate and favorable clinical outcome for posterior circulation non-saccular aneurysms treated with SAC and FD. Stroke was the most common complication regardless of treatment modality, and a lower periprocedural complication rate was noted with SAC. Further studies are needed with the primary focus of reducing the risk of stroke with either modality.

The Fate of Unruptured Intracranial Vertebrobasilar Dissecting Aneurysm with Brain Stem Compression According to Different Treatment Modalities

BACKGROUND AND PURPOSE

Unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression are difficult to treat. In the present study, the clinical and radiologic outcomes of unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression based on different treatment modalities were evaluated.

MATERIALS AND METHODS

This study included 28 patients with unruptured intracranial vertebrobasilar dissecting aneurysms with brain stem compression treated from January 2009 to December 2017. Treatment methods were observation (n = 6), stent-assisted coil embolization (n = 9), parent artery occlusion (n = 6), and flow diversion (n = 7). The data of baseline characteristics, change of aneurysm size, retreatment rate, stroke occurrence, and alteration of the mRS score were obtained from retrospective chart review.

RESULTS

The initial size of dissecting aneurysms was largest in the flow diversion group (22.5 ± 7.7 mm), followed by parent artery occlusion (20.3 ± 8.4 mm), stent-assisted coil embolization (11.7 ± 2.2 mm), and observation (17.8 ± 5.5 mm; P = .01) groups. The reduction rate of aneurysm size was highest in the parent artery occlusion group (26.7 ± 32.1%), followed by flow diversion (14.1% ± 28.7%), stent-assisted coil embolization (-17.9 ± 30.3%), and observation (-31.5 ± 30.8%; P = .007) groups. Additional treatment was needed in the observation (4/6, 66.7%) and stent-assisted coil embolization (3/9, 33.3%; P = .017) groups. Improvement of the mRS score on follow-up was observed in the flow diversion (6/7, 85.7%) and parent artery occlusion (4/6, 66.7%) groups but not in the stent-assisted coil embolization and observation groups. A worsened mRS score was most common in the observation group (4/6, 66.7%), followed by stent-assisted coil embolization (3/9, 33.3%), parent artery occlusion (2/6, 33.3%), and flow diversion (0/7, 0%) groups.

CONCLUSIONS

When treating intracranial vertebrobasilar dissecting aneurysms with brain stem compression, parent artery occlusion and flow diversion should be considered to reduce aneurysm size and improve the mRS score.

Intracranial Mirror Aneurysms: Anatomic Characteristics and Treatment Options

Objective

Mirror aneurysms are generally considered as a subset of multiple aneurysms, defined as aneurysms occurring bilaterally and symmetrically on the same-named vessels. Although not infrequent, the characteristics of mirror aneurysms are not well studied. This investigation was conducted to elucidate the anatomic features of such lesions and examine treatment options.

Materials and Methods

A retrospective review was conducted, aimed at 172 patients treated for 344 mirror aneurysms between January 2007 and December 2015. Aneurysms of similar nature but in asymmetric locations on the same-named vessels were excluded. All available records were examined and lesion characteristics, as well as treatment outcomes were assessed.

Results

In study subjects (n = 172), mirror aneurysms most often involved middle cerebral artery bifurcation (n = 83), followed by a paraclinoid internal carotid artery (n = 50) and posterior communicating artery (n = 21). Most of the lesions (95.3%) measured ≤ 10 mm, and in 126 patients (74.6%), the size ratios were > 50%. Of the 344 aneurysms studied, coil embolization was undertaken in 217, surgical clipping in 62, and observation alone (no treatment) in 65. Coil embolization and surgical clipping were done bilaterally in 83 and 12 patients, respectively. In 12 patients, combined coiling and clipping were implemented on each side. Single-stage coil embolization of both the aneurysms was performed in 73 patients, with excellent post-procedural (85.6%) and follow-up (86.8%) occlusive results. There was no procedure-related morbidity or mortality.

Conclusion

By adopting different treatment strategies to different configurations and vascular sources, mirror aneurysms can be safely and effectively treated. If feasible, single-stage coil embolization should be considered as a reasonable treatment option for mirror aneurysms.

Dissecting Vertebral Artery Aneurysm Presenting Regrowth After Stent-Assisted Coil Embolization in Acute Stage

For a case of dissecting vertebral artery aneurysm (DVAA) in a dominant vertebral artery (VA) or posterior inferior cerebellar artery (PICA)-involving lesion, stent-assisted coil embolization (SACE) is an effective technique to preserve blood flow of the VA. A 41-year-old man presented with subarachnoid hemorrhage. Angiography demonstrated DVAA on the left VA just distal to the PICA, and the right VA was thinner than the left. For this case, SACE was performed to preserve the left VA and PICA. On the 10th day, angiography showed recurrence of the dissection. The dissected portion had thickened and extended to both distal and proximal sides involving the PICA origin and proximal portion to the PICA. A second endovascular embolization was performed and the recurrent dissecting aneurysm was embolized including the main VA cavity. In cases of DVAA, there is a possibility of recurrence after SACE, if a dissecting cavity remains unembolized. Therefore, total embolization is necessary under close observation from multiple angles, including the down-the-barrel view.