Strategies and Outcomes of Endovascular Treatment for Ruptured Vertebral Artery Dissecting Aneurysms: A Single-Center Experience with 44 Consecutive Cases

Haibin Chen; Qi Jia; Guosai Zhang; Linbo Zhao; Sheng Liu

doi:10.5469/neuroint.2026.00381

Neurointervention > Volume 21(2); 2026 > Article

Chen, Jia, Zhang, Zhao, and Liu: Strategies and Outcomes of Endovascular Treatment for Ruptured Vertebral Artery Dissecting Aneurysms: A Single-Center Experience with 44 Consecutive Cases

Original Paper

Neurointervention 2026;21(2):70-78.

Print publication date: July 2026

Published online: June 5, 2026

DOI: https://doi.org/10.5469/neuroint.2026.00381

Strategies and Outcomes of Endovascular Treatment for Ruptured Vertebral Artery Dissecting Aneurysms: A Single-Center Experience with 44 Consecutive Cases

Haibin Chen, PhD^1,^*

, Qi Jia, PhD^2,^*

, Guosai Zhang, PhD¹

, Linbo Zhao, MD¹

, Sheng Liu, MD¹

¹Department of Interventional Radiology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, China

²Neurointerventional Center, Affiliated Hospital of Nantong University, Nantong, China

Correspondence to: Sheng Liu, MD Department of Interventional Radiology, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Rd, Nanjing 210029, China E-mail: liusheng@njmu.edu.cn

Linbo Zhao, MD Department of Interventional Radiology, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Rd, Nanjing 210029, China E-mail: linberzhao@hotmail.com

^* These authors contributed equally to the manuscript as first author.

Received April 6, 2026 Revised May 13, 2026 Accepted May 23, 2026

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To evaluate the clinical outcomes of endovascular treatment for ruptured vertebral artery dissecting aneurysms (VADAs), with a focus on endovascular protocols tailored to different anatomical subtypes.

Materials and Methods

We retrospectively analyzed 44 consecutive patients with ruptured VADAs treated from December 2014 to October 2024. Treatment strategies were guided by aneurysm location: parent artery occlusion (PAO) was used for lesions in non-dominant VAs, while stent-assisted coiling (SAC) reconstruction was used for aneurysms in dominant VAs. Patients were stratified by modified Rankin Scale (mRS) scores at 3-month follow-up (favorable: mRS 0–2; unfavorable: mRS 3–6).

Results

All procedures were technically successful, including 12 single SAC, 13 overlapping SAC, and 19 with PAO (2 involving posterior inferior cerebellar artery preservation). Immediate complete occlusion was achieved in 50.0% of single SAC cases, 76.9% overlapping SAC, and 100% in the PAO group. Six (13.6%) procedure-related complications occurred, including 2 hemorrhagic and 4 ischemic events. Thirty patients (68.2%) had favorable outcomes, and the unfavorable outcomes group showed a higher incidence of ischemic events (P=0.012). An initial poor Hunt–Hess grade (≥IV) was an independent risk factor for unfavorable outcomes (odds ratio 6.35, 95% confidence interval 1.24–32.59; P=0.027). Angiographic follow-up was performed for 34 aneurysms, with complete occlusion achieved in 32 (94.1%); the remaining 2 patients were retreated.

Conclusion

Endovascular management is safe and effective for ruptured VADAs. Anatomical stratification—PAO for non-dominant VA lesions and SAC for dominant VA aneurysms—may help achieve favorable outcomes.

Key Words: Vertebral artery; Ruptured; Dissecting aneurysm; Endovascular treatment

INTRODUCTION

Ruptured intracranial vertebral artery dissecting aneurysms (VADAs) are associated with poor prognosis. If untreated, the re-rupture rate can range from 30% to 70% and the mortality rate can reach 46.7% [1-4]. Thus, the primary goal of treatment is to prevent re-rupture, and parent artery occlusion (PAO) (including the rupture site) has been proposed as a definitive solution. However, PAO eliminates anterograde flow, thereby increasing the risk of perforator infarction or vertebrobasilar ischemia and complicating the management of acute cerebral circulation during vasospasm. In contrast, reconstructive strategies aimed at preserving antegrade flow—such as single-stent-assisted coiling (SAC), multilayer stenting, or flow diverters (FDs)—have been increasingly validated in recent studies [1-3]. Reconstructive techniques are particularly indicated in situations such as significant asymmetry in VA diameter when the dissecting aneurysm occurs in the dominant VA, or with lesions involving posterior inferior cerebellar arteries (PICAs) [5]. Limitations of these approaches include the off-label use of stents or FDs in the acute phase, a potential high risk of rebleeding, and a lack of high-level evidence guiding antithrombotic management [6].

The choice between deconstructive (PAO) and reconstructive techniques hinges on balancing the need to preserve parent vessel/perforator patency against the goal of preventing acute re-rupture. Currently, no consensus exists on risk-adaptive protocols for anatomical subtypes [7]. This study introduces our experience of endovascular treatment protocol based on VA dominance and PICA involvement, validated in 44 consecutive cases of ruptured VADAs.

MATERIALS AND METHODS

Patient Cohort and Anatomical Stratification

Forty-four consecutive patients with angiographically confirmed ruptured VADAs treated between December 2014 and October 2024 were included. Inclusion criteria were as follows: (1) acute subarachnoid hemorrhage (SAH) confirmed by computed tomography (CT); (2) VADA identified via digital subtraction angiography (DSA); and (3) endovascular treatment within 72 hours of SAH onset. Exclusion criteria included traumatic dissections, unruptured aneurysms, or incomplete follow-up.

Dominant VA was defined as an absence of the contralateral VA, termination of the contralateral VA at the PICA, or ≥a 1.5-fold diameter difference between the bilateral VAs. Codominant VAs were regarded as non-dominant [8]. The patient’s clinical status at admission was assessed using the Hunt and Hess grading system.

Endovascular Protocol

The endovascular treatment strategy was determined based on VA dominance and the anatomical relationship of the dissection site to PICA. For non-dominant VA lesions, PAO (a deconstructive technique) was performed, with coil embolization extended 2–5 mm proximal to the lesion. In non-dominant VA aneurysms involving the PICA, PICA-preserving techniques using small-size stent (Atlas/Leo Baby) were applied prior to occlusion (Fig. 1).

Reconstructive stent-based techniques were preferred for VADAs in the dominant VA. For dominant VA aneurysms with VA stenosis, single laser-cut stents (Neuroform/Enterprise) with SAC were used (Fig. 2). Fig. 3 illustrates the management of a dominant-side VADA involving PICA. When dense embolization was challenging with laser-cut stents, the low-profile visualized intraluminal support (LVIS) stent was deployed using the “lantern technique” to reconstruct the aneurysm neck and achieve optimal occlusion. For all other cases, overlapping SAC was prioritized, combing laser-cut stents for scaffolding and braided stents (LVIS) for flow diversion (Fig. 4). All cases during the study period were treated according to the above-mentioned treatment strategy.

Antiplatelet regimens included intraprocedural tirofiban and postoperative dual therapy. Tirofiban was administered intravenously as a loading dose (5 μg/kg) immediately after stent placement, followed by a maintenance dose of 0.1 μg/kg/min for 24 hours. All patients received dual antiplatelet therapy (100 mg of aspirin and 75 mg of clopidogrel) for at least 3 months, followed by monotherapy with 100 mg aspirin for at least 1 year.

Procedural Complications and Outcome Assessment

Technical success was defined as successful stent insertion and coil embolization. Hemorrhagic events include intraprocedural rupture (contrast extravasation) and intracerebral hemorrhage detected by CT within 72 hours. Thromboembolic events included intraoperative acute thrombosis and postoperative ischemic events. Clinical outcomes at 3 months were evaluated with the modified Rankin Scale (mRS): favorable (mRS: 0–2) and unfavorable (mRS: 3–6).

Statistical Analysis

Statistical analysis was performed using IBM SPSS for Windows v.26.0 (IBM Co.). Pearson’s chi-square or Fisher’s exact test was performed to compare categorical variables. Univariate and multivariate logistic regression models were applied to identify the variables associated with unfavorable clinical outcomes. Significant variables (P<0.1) detected in the univariate models were entered into the multivariate logistic regression model. A 2-tailed P-value<0.05 was considered statistically significant.

RESULTS

Baseline Characteristics

The cohort included 44 patients with a mean age of 56.8±12.1 years and a male predominance (52.3%, n=23). Hypertension was the most common risk factor (47.7%, n=21), followed by diabetes (22.7%, n=10), smoking (13.6%, n=6), and alcohol abuse (11.4%, n=5). Eleven patients (25.0%) presented with an initial poor Hunt–Hess grade (≥IV), and 24 (54.5%) had a Fisher grade ≥III. The mean maximal aneurysm size was 7.1±2.9 mm. Anatomically, 25 aneurysms (56.8%) were located in the dominant VA, and 9 (20.5%) involved the PICA. Baseline characteristics are presented in Table 1.

Endovascular Treatment and Procedural Complications

Endovascular approaches included 12 cases (27.3%) of single SAC, 13 (29.5%) of overlapping SAC, and 19 (43.1%) of PAO (2 PICA preservation). A total of 6 patients (13.6%) experienced procedure-related complications. Immediate complete occlusion rates were 50.0% (n=6/12) in the single SAC group, 76.9% (n=10/13) in the overlapping SAC group, and 100% in the PAO group.

Intraprocedural complications occurred in 3 patients (6.8%). Two cases of intraprocedural re-rupture were managed successfully with protamine-mediated heparin reversal and accelerated coil embolization, resulting in favorable outcomes (mRS≤2). The other patient developed acute in-stent thrombosis. Despite intra-arterial tirofiban administration and aspiration thrombectomy, the condition was refractory, leading to mortality. All intraprocedural complications occurred in the single SAC group.

Post-procedure ischemic events were observed in 3 cases (6.8%). One patient developed hemiplegia with no evidence of major vessel occlusion on DSA, and no significant improvement after intra-arterial infusion of tirofiban. One patient experienced severe cerebrovascular spasm, which resolved with intra-arterial infusion of fasudil. Routine surveillance head CT detected a focal cerebellar infarction in another patient, who subsequently died due to critical admission status (Fisher grade IV, Hunt–Hess grade V). All post-procedural ischemic events occurred in the overlapping SAC group.

Clinical and Angiographic Outcomes

Favorable 3-month clinical outcomes were achieved in 30 patients (68.2%). No baseline characteristics differed significantly between the favorable and unfavorable outcome groups (all P>0.05; Table 2). Ischemic events were associated with poor clinical outcomes, particularly post-procedural ischemic events (P=0.012). Patients with an initial poor initial Hunt–Hess grades (≥IV) had significantly poorer outcomes (P=0.025).

Angiographic follow-up was performed for 34 aneurysms (6 deceased, 4 declined), with complete occlusion achieved in 32 (94.1%). Two patients with increased aneurysm volume underwent retreatment: one received an additional LVIS stent within the existing Enterprise stent followed by dense coiling, and the other patient (initially treated with overlapping SAC) underwent FD placement.

Risk Factors for Unfavorable 3-Month Outcomes

Univariate analysis identified initial poor Hunt–Hess grade (≥IV) (odds ratio [OR] 6.50, 95% confidence interval [CI] 1.47–28.70; P=0.014) and diabetes (OR 4.87, 95% CI 1.10–21.69; P=0.038) as significantly predictors of unfavorable outcomes. Multivariate regression confirmed initial poor Hunt–Hess grade (≥IV) as an independent risk factor (OR 6.35, 95% CI 1.24–32.59; P=0.027) (Table 3).

DISCUSSION

This study evaluated 44 consecutive patients with ruptured VADAs, with treatment stratified by VA dominance: SAC for dominant VAs (25 cases: 12 single SAC, 13 overlapping SAC) and PAO for non-dominant VAs (19 cases). Procedure-related complications occurred in 6 SAC cases (24.0%), with no complications in the PAO group. Notably, 2 patients with non-dominant VAs and PICA involvement underwent complete VA occlusion with low-profile stents (Atlas/Leo Baby) to preserve PICA patency, with no procedural complications or recurrence. At our institution, low-profile stents are deployed to preserve larger-caliber PICAs when involved, and embolization is confined to 2–5 mm proximal to the VADA to minimize perforator compromise—technical refinements that likely contributed to the favorable outcomes in the PAO cohort.

PAO is effective for preventing acute re-rupture but is associated ischemic complications in previous studies [1,9,10]. Lee et al. [11] reported procedure-related ischemic events in 25.0% (6/24) of PAO-treated ruptured VADAs and an 8.3% (2/24) recurrence rate. Madaelil et al. [12] noted cerebral infarction in 20.0% (2/10) of PAO cases, including 1 patient with significant disability due to PICA territory infarction, likely secondary to vasospasm or thromboembolism. PICA involvement is a known risk factor for poor outcomes; while PICA bypass was previously favored for cases where PAO was contraindicated, advances in interventional techniques have expanded options for VADAs involving the PICA [1,7,13,14]. Chen et al. [15] reported 7 cases of stenting from the distal VA to the PICA in PICA-involved VADAs, with 1 patient (14.3%) experiencing a small lateral brainstem infarction. Cho et al. [16] described 3 patients with ruptured VADAs who underwent PAO after PICA stenting, with 1 case of cerebellar infarction. Lee et al. [11] documented 3 procedural ischemic events among 4 fusiform VADAs treated with PICA stenting, with 1 recurrence during follow-up. In contrast, our 19 PAO-treated patients (including 2 PICA preservation via small-profile stents) showed no procedural complications or recurrence.

Deconstructive treatment is challenging in dominant VAs, making reconstructive techniques necessary when vessel sacrifice is contraindicated. Single SAC is technically simpler than overlapping SAC but faces challenges with immediate occlusion rates and re-rupture complications. Zhao et al. [6] reported peri-procedural hemorrhagic events in 14.3% (3/21) of single SAC cases, comparable to our rate of 16.7% (2/12). All hemorrhagic events in our study occurred in the single SAC group, potentially due to inadequate flow diversion by a single stent to prevent re-rupture and incomplete immediate occlusion (50.0%, 6/12), which increases hemorrhagic risk. Zhao et al. [17] demonstrated that overlapping SAC significantly reduces recurrence compared to single SAC (2.1% vs. 18.0%, P=0.01). Our study was underpowered to detect a statistically significant difference (single: 8.3% vs. overlapping 7.7%). This propensity for re-rupture reminds us that antiplatelet therapy should be used with caution in cases of stent‑assisted coiling. For patients undergoing single SAC, tirofiban should be administered only after complete occlusion of the aneurysm sac has been confirmed, thereby reducing the risk of aneurysm re-rupture attributable to antiplatelet agents. For cases requiring overlapping SAC, the combination of a laser‑cut stent and a braided stent typically exert a certain flow‑diversion effect, providing sufficient protection for the aneurysm.

Ischemic complications are a key concern in overlapping SAC [18,19]. Wu et al. [20] reported a 2.9% (1/34) ischemic complication rate in ruptured vertebrobasilar dissecting aneurysms treated with overlapping SAC (e.g., LVIS-within-Enterprise), while Shi et al. [21] noted a thromboembolic rate of 9.8% (4/41) across vertebrobasilar dissecting aneurysms. Our study observed ischemic events in 23.1% (3/13) of ruptured VADAs treated with overlapping stents, a higher rate possibly due to the exclusive inclusion of ruptured VADAs (necessitating more conservative antiplatelet regimens due to SAH) and a small sample size.

Managing dominant VADAs with PICA involvement is clinical challenge, as continuous perfusion from the PICA into unprotected residual dissecting segments promote recurrence [22]. Complete embolization is inherently limited in these cases, regardless of stent technique. Cho et al. [16] reported recurrence in 25.0% (3/12) of PICA-involved VADAs treated with SAC (1/4 overlapping SAC, 2/8 single SAC). In our cohort, targeted coiling sparing the PICA orifice was to preserve PICA, as shown in Fig. 3, with only 1 recurrence (11.1%, 1/9) during follow-up. Bypass surgery (e.g., VA-PICA, PICA-PICA, or occipital artery-PICA bypass) may yield favorable outcomes for this subtype by enabling definitive aneurysm management while preserving flow in the dominant VA and PICA [23].

Data on FDs for ruptured VADAs are limited and mixed. Catapano et al. [24] reported 2 acute rebleeding events and 3 retreated among 7 patients. Chan et al. [25] noted minor procedural complications in 2 of 6 patients, with complete occlusion in all cases at follow-up. Duangprasert et al. [26] demonstrated favorable outcomes in 13 cases, with 61.5% achieving complete occlusion within 2 weeks and 92.3% good clinical outcomes, with no procedural complications. However, FD use in ruptured VADAs remains controversial due to challenges in acute-phase antithrombotic management and rebleeding risk, leading us to exclude FDs from our protocol. Off-label FD use for ruptured VADAs requires further investigation in large multicenter studies.

Unfavorable outcome for ruptured VADAs range from 40.0% to 53.8% in previous reports [11,24]. Our study identified initial poor Hunt–Hess grading (≥IV) as an independent risk factor for unfavorable outcomes, consistent with prior research [9,11,27]. A poor initial Hunt–Hess grade indicates severe neurological impairment, likely due to larger SAH volume, increased intracranial pressure, and disrupted cerebrovascular physiology, rendering patients more vulnerable to deterioration during treatment and recovery.

Our study has several limitations. Compared with some previous reports, we did not employ newer endovascular devices such as FDs or other innovative treatment strategies; thus, no novel technical insight is provided. Nevertheless, we believe that our findings still offer valuable and reliable evidence. Our study represents a relatively homogeneous cohort of patients with ruptured VADAs, and the sample size (44 consecutive cases) is larger than that of most prior single‑center series. More importantly, we strictly adhered to a predefined treatment protocol throughout the entire study period without any mid‑course adjustments. This consistency in treatment allocation enhances the internal validity of our results. Therefore, while lacking technological novelty, the robustness of our outcomes is supported by the larger, more uniform patient cohort and the unwavering application of a consistent treatment strategy. This study has selection bias due to the strict adherence to the treatment strategy selection among different treatment groups. Therefore, it is impossible to conduct a causal analysis between the treatment methods and clinical prognosis. A prospective multi-center study is supposed to be conducted for verification. Subgroup analyses (e.g., FDs) are limited by small sample sizes. Long-term data on occlusion durability, vessel patency, and neurological outcomes are lacking, which are critical for assessing delayed complications like in-stent stenosis. While our PICA preservation technique using low-profile stents shows promise, long-term efficacy requires confirmation.

CONCLUSION

Endovascular management of ruptured VADAs is safe and effective when stratified by anatomy: PAO for non-dominant VA lesions and SAC for dominant VA aneurysms. PICA preservation using small-size stents appears safe and effective for PICA-involved aneurysms but requires further study. An initial poor Hunt–Hess grade (≥IV) is an independent risk factor for unfavorable clinical outcomes.

Notes

Fund

This work was supported by National Natural Science Foundation of China (82472085).

Ethics Statement

This study was approved by the ethics committee of The First Affiliated Hospital with Nanjing Medical University (2025-SR-535). All procedures performed in the studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 2024 Helsinki Declaration and its later amendments or comparable ethical standards. We anonymized the patient information such as sex and age that could identify an individual. Based on the retrospective study design, the requirement for patient informed consent for study inclusion was waived.

Conflicts of Interest

The authors have no conflicts to disclose.

Author Contributions

Concept and design: HC. Analysis and interpretation: HC, QJ, and GZ. Data collection: HC. Writing the article: HC. Critical revision of the article: LZ and SL. Final approval of the article: SL. Statistical analysis: HC. Obtained funding: SL. Overall responsibility: SL.

Fig. 1.

DSA showed a left ruptured VADA involving PICA (non-dominant) (A). (B) illustrates the technique for PAO with PICA stenting. The white arrow designates the marker band of the stent (Atlas) within the PICA (C). Six-month follow-up angiography demonstrated robust perfusion through the right VA with preserved patency of the left PICA (D, E). DSA, digital subtraction angiography; VADA, vertebral artery dissecting aneurysm; PICA, posterior inferior cerebellar artery; PAO, parent artery occlusion.

Fig. 2.

DSA identified a VADA with distal VA stenosis (A). Single SAC (Enterprise) was performed successfully (B). The DSA follow-up revealed enlargement of the VADA (C). It was decided to release an LVIS within the original Enterprise and increase the number of coils (D, E). Six months later, the aneurysm disappeared, and the blood flow of the parent artery was unobstructed (F). DSA, digital subtraction angiography; VADA, vertebral artery dissecting aneurysm; SAC, stent-assisted coiling; LVIS, low-profile visualized intraluminal support.

Fig. 3.

Angiography revealed a right VADA adjacent to the origin of the PICA with distal arterial stenosis (A). Single SAC was performed to treat the aneurysm while preserving PICA patency (B). At 6-month angiographic follow-up, DSA confirmed preserved PICA flow (C) and complete aneurysm occlusion (D). VADA, vertebral artery dissecting aneurysm; PICA, posterior inferior cerebellar artery; SAC, stent-assisted coiling; DSA, digital subtraction angiography.

Fig. 4.

A patient was found to have a VADA located on a dominant VA (A). So, overlapping SAC was performed for treatment (B). The position of the postprocedural stents and coils was satisfactory (C). At 6-month follow-up, the aneurysm had been completely occluded (D). VADA, vertebral artery dissecting aneurysm; SAC, stent-assisted coiling.

Table 1.

Characteristics of patients and ruptured VADAs (n=44)

Characteristic	Value
Age (y)	56.8±12.1
Male, sex	23 (52.3)
Risk factor
Hypertension	21 (47.7)
Diabetes mellitus	10 (22.7)
Smoking	6 (13.6)
Alcohol	5 (11.4)
Ischemic stroke history	12 (27.3)
Fisher grade (≥III)	24 (54.5)
Initial poor Hunt–Hess grade (≥IV)	11 (25.0)
Maximal size (mm)	7.1±2.9
Aneurysm location
Right	30 (68.2)
Dominant VA	25 (56.8)
PICA involvement	9 (20.5)
Treatment mode
PAO	19 (43.2)
Single SAC	12 (27.3)
Overlapping SAC	13 (29.5)

Values are presented as mean±standard deviation or number (%).

VADAs, vertebral artery dissecting aneurysms; PICA, posterior inferior cerebellar artery; PAO, parent artery occlusion; SAC, stent-assisted coiling.

Table 2.

Characteristics of VADAs patients with different clinical outcomes

Characteristic	Favorable (n=30)	Unfavorable (n=14)	P-value
Age (y)	55.4±8.8	59.6±17.4	0.411
Male, sex	17 (56.7)	6 (42.9)	0.393
Initial poor Hunt–Hess grade (≥ IV)	4 (13.3)	7 (50.0)	0.025
Fisher grade (≥III)	15 (50.0)	9 (64.3)	0.375
Risk factor
Smoking	5 (16.7)	1 (7.1)	0.700
Alcohol	5 (16.7)	0 (0.0)	0.266
Hypertension	15 (50.0)	6 (42.9)	0.659
Diabetes mellitus	4 (13.3)	6 (42.9)	0.073
Ischemic stroke history	6 (20.0)	6 (42.9)	0.222
Maximal size (mm)	6.8±2.9	7.7±3.0	0.372
Aneurysm location
Right	20 (66.7)	10 (71.4)	>0.999
Dominant VA	12 (40.0)	5 (35.7)	0.786
PICA involvement	4 (13.3)	5 (35.7)	0.189
Treatment mode			0.848
PAO	13 (43.3)	6 (42.9)
Single SAC	9 (30.0)	3 (21.4)
Overlapping SAC	8 (26.7)	5 (35.7)
Ischemic event	0 (0.0)	4 (28.6)	0.012
Intraprocedural	0 (0.0)	1 (7.1)	0.318
Postprocedural	0 (0.0)	3 (21.4)	0.027
Intraprocedural hemorrhagic event	2 (10.0)	0 (0.0)	0.540
Immediate incomplete occlusion	5 (16.7)	4 (28.6)	0.610

Values are presented as mean±standard deviation or number (%).

VADAs, vertebral artery dissecting aneurysms; PICA, posterior inferior cerebellar artery; PAO, parent artery occlusion; SAC, stent-assisted coiling.

Table 3.

Risk factors for unfavorable clinical outcomes after endovascular treatment

Variable	Univariate		Multivariate
Variable	P-value	OR (95% CI)	P-value	OR (95% CI)
Initial poor Hunt–Hess grade (≥IV)	0.014	6.50 (1.47–28.70)	0.027	6.35 (1.24–32.59)
Diabetes mellitus	0.038	4.87 (1.10–21.69)
PICA involvement	0.097	3.61 (0.70–16.47)
Procedural complication	0.067	5.60 (0.89–35.42)

OR, odds ratio; CI, confidence interval; PICA, posterior inferior cerebellar artery.

REFERENCES

1. Guan J, Li G, Kong X, He C, Long J, Qin H, et al. Endovascular treatment for ruptured and unruptured vertebral artery dissecting aneurysms: a meta-analysis. J Neurointerv Surg 2017;9:558-563.

2. Lee M, Park IS, Lee KH, Park H, Lee CH, Han JW. Endovascular treatments for ruptured intracranial vertebral artery dissecting aneurysms: experience in 16 patients. J Cerebrovasc Endovasc Neurosurg 2017;19:268-275.

3. Schob S, Becher A, Bhogal P, Richter C, Hartmann A, Köhlert K, et al. Segment occlusion vs. reconstruction-a single center experience with endovascular strategies for ruptured vertebrobasilar dissecting aneurysms. Front Neurol 2019;10:207

4. Bhogal P, Brouwer PA, Söderqvist ÅK, Ohlsson M, Andersson T, Holmin S, et al. Patients with subarachnoid haemorrhage from vertebrobasilar dissection: treatment with stent-in-stent technique. Neuroradiology 2015;57:605-614.

5. Kong X, Sun Z, Ling C, Xu L, Qian C, Yu J, et al. Endovascular treatment for ruptured vertebral dissecting aneurysms involving PICA: reconstruction or deconstruction? Experience from 16 patients. Interv Neuroradiol 2021;27:163-171.

6. Zhao X, Wang H, Liu J, Zhang Z, Li Z. Endovascular treatment of vertebral artery dissecting aneurysm: a single-center experience. Exp Ther Med 2019;18:4838-4844.

7. Liu P, Li Z, Hu L, Liu Y, Li P, Zhu W, et al. Clinical characteristics, endovascular choices, and surgical outcomes of intracranial vertebral artery dissecting aneurysms: a consecutive series of 196 patients. J Neurosurg 2022;138:215-222.

8. Hong JM, Chung CS, Bang OY, Yong SW, Joo IS, Huh K. Vertebral artery dominance contributes to basilar artery curvature and peri-vertebrobasilar junctional infarcts. J Neurol Neurosurg Psychiatry 2009;80:1087-1092.

9. Lee JM, Kim TS, Joo SP, Yoon W, Choi HY. Endovascular treatment of ruptured dissecting vertebral artery aneurysms--long-term follow-up results, benefits of early embolization, and predictors of outcome. Acta Neurochir (Wien) 2010;152:1455-1465.

10. Anxionnat R, de Melo Neto JF, Bracard S, Lacour JC, Pinelli C, Civit T, et al. Treatment of hemorrhagic intracranial dissections. Neurosurgery 2003;53:289-300 discussion 300-301

11. Lee HJ, Cho WC, Choi JH, Kim BS, Shin YS. Comparison of parent artery occlusion and stent-assisted treatments in ruptured vertebral artery dissecting aneurysms. World Neurosurg 2022;167:e533-e540.

12. Madaelil TP, Wallace AN, Chatterjee AN, Zipfel GJ, Dacey RG, Cross DT, et al. Endovascular parent vessel sacrifice in ruptured dissecting vertebral and posterior inferior cerebellar artery aneurysms: clinical outcomes and review of the literature. J Neurointerv Surg 2016;8:796-801.

13. Shi L, Xu K, Sun X, Yu J. Therapeutic progress in treating vertebral dissecting aneurysms involving the posterior inferior cerebellar artery. Int J Med Sci 2016;13:540-555.

14. Czabanka M, Ali M, Schmiedek P, Vajkoczy P, Lawton MT. Vertebral artery-posterior inferior cerebellar artery bypass using a radial artery graft for hemorrhagic dissecting vertebral artery aneurysms: surgical technique and report of 2 cases. J Neurosurg 2011;114:1074-1079.

15. Chen YA, Qu RB, Bian YS, Zhu W, Zhang KP, Pang Q. Stent placement to treat ruptured vertebral dissecting aneurysms. Interv Neuroradiol 2013;19:479-482.

16. Cho DY, Choi JH, Kim BS, Shin YS. Comparison of clinical and radiologic outcomes of diverse endovascular treatments in vertebral artery dissecting aneurysm involving the origin of PICA. World Neurosurg 2019;121:e22-e31.

17. Zhao KJ, Zhao R, Huang QH, Xu Y, Hong B, Fang YB, et al. The interaction between stent(s) implantation, PICA involvement, and immediate occlusion degree affect symptomatic intracranial spontaneous vertebral artery dissection aneurysm (sis-VADA) recurrence after reconstructive treatment with stent(s)-assisted coiling. Eur Radiol 2014;24:2088-2096.

18. Peng Q, Zhou Y, Li W, Wang C, Dong L, Mu S, et al. Reconstructive endovascular treatment of basilar trunk and vertebrobasilar junction aneurysms: a review of 77 consecutive cases. Front Neurol 2022;13:885776

19. Wu Q, Wang C, Xu S, Ji Z, Qi J, Li Y, et al. Low-profile visualized intraluminal support-within-Enterprise overlapping-stent technique versus flow diversion in the treatment of intracranial vertebrobasilar trunk dissecting aneurysms. Quant Imaging Med Surg 2023;13:3536-3546.

20. Wu Q, Meng Y, Chen A, Xu S, Wang C, Ji Z, et al. LVIS-within-enterprise double-stent technique with coil embolization in the treatment of patients with acutely ruptured intracranial vertebrobasilar artery-dissecting aneurysms. Front Neurol 2023;14:1069380

21. Shi G, Xu S, Gareev I, Ji Z, Pei W, Zhang G, et al. Overlapping stent-assisted coil embolization for vertebrobasilar dissecting aneurysms: a single-center study. Neurol Res 2021;43:701-707.

22. Kim BM, Shin YS, Kim SH, Suh SH, Ihn YK, Kim DI, et al. Incidence and risk factors of recurrence after endovascular treatment of intracranial vertebrobasilar dissecting aneurysms. Stroke 2011;42:2425-2430.

23. Brenner LBO, Sousa MP, Semione G, Ferreira MY, Batista S, Palavani LB, et al. Posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass versus occipital artery-posterior inferior cerebellar artery bypass for treating posterior circulation aneurysms: a systematic review and comparative meta-analysis. World Neurosurg 2024;185:403-416.e7.

24. Catapano JS, Ducruet AF, Cadigan MS, Farhadi DS, Majmundar N, Nguyen CL, et al. Endovascular treatment of vertebral artery dissecting aneurysms: a 20-year institutional experience. J Neurointerv Surg 2022;14:257-261.

25. Chan RS, Mak CH, Wong AK, Chan KY, Leung KM. Use of the pipeline embolization device to treat recently ruptured dissecting cerebral aneurysms. Interv Neuroradiol 2014;20:436-441.

26. Duangprasert G, Sukhor S, Ratanavinitkul W, Tantongtip D. Evaluation of flow diverter use in acutely ruptured vertebral artery dissecting Aneurysms: a focus on safety and efficacy for rapid Aneurysm obliteration. Clin Neurol Neurosurg 2024;242:108345

27. Urasyanandana K, Withayasuk P, Songsaeng D, Aurboonyawat T, Chankaew E, Churojana A. Ruptured intracranial vertebral artery dissecting aneurysms: an evaluation of prognostic factors of treatment outcome. Interv Neuroradiol 2017;23:240-248.