Posterior atlantoaxial fusion as treatment option for extracranial vertebral artery dissecting aneurysm: a case report and literature review

Outcomes following surgical and endovascular treatment of extracranial vertebral artery aneurysms (VAA): a systematic evaluation of the literature

Extracranial vertebral artery aneurysms are rare complications resulting from trauma and multiple different diseases. However, the difference between clinical and surgical profiles is well understood. To investigate the clinical and interventional outcomes following extracranial vertebral artery aneurysms (VAA) treatment through a systematic review of the literature to date, an electronic database search for full-text English articles was conducted following PRISMA guidelines. The search yielded results on clinical and surgical outcomes for extracranial VAAs. These results included patient-specific risk factors, indications, and techniques. Our literature search resulted in 561 articles, of which 36 studies were qualified to be included in the analysis. A total of 55 patients with multiple various extracranial VAA incidents were included. The mean age of subjects was 42 years (ranging from 13.0 to 76.0 years), and the majority of patients were males (71%, n =39). Blunt trauma was the most frequent risk factor for extracranial VAA formation (35%, n = 19). The majority of aneurysms (60%) were dissected in nature. The most common form of treatment for extracranial VAAs was the use of a flow diverter (24%, n=13). Overall, five (9%) patients had long-term adverse neurological complications following intervention with 5% (n=3) mortality, 2% (n=1) resulting in unilateral vocal cord paralysis, and 2% (n=1) resulted in a positive Romberg sign. The mortality rate is 15.7% in the surgical group, whereas the endovascular treatment did not result in any mortality. The endovascular approach is a safe and effective treatment of extracranial VAAs due to its relatively low overall complication rate and lack of resulting mortality. This is in contrast to the surgical approach which results in a higher rate of complications, recurrence, and mortality outcomes. An understanding of the factors and clinical outcomes associated with the incidence of extracranial VAAs is essential for the future improvement of patient outcomes.

Craniovertebral junction aneurysms

OBJECTIVE

The course of the vertebral artery and its relationship to the C_0-1-2 structures render it particularly vulnerable to mechanical trauma. In the present study, we investigated the course of vertebral arteries along the craniovertebral junction (CJ) to cast light on the biomechanical aspects of aneurysm formation, focusing mainly on the relation of the vertebral artery injuries to the CJ bony landmarks. Herein, we report our experience with fourteen cases of craniovertebral junction vertebral artery (CJVA) aneurysms and their presentations, management, and outcomes.

MATERIALS AND METHODS

We extracted from 83 vertebral artery aneurysms only those 14 cases whose aneurysms were located at the C_0-1-2. We reviewed all medical records, including operative reports and radiologic images. We divided the CJVA into 5 segments and then carefully reviewed the cases, largely focusing on the CJVA segments involved in the aneurysm. Angiographic outcomes were determined by angiography, which was scheduled at 3-6 months, 1, 2.5, and 5 years postoperatively.

RESULTS

A total of 14 patients with CJVA aneurysms were included in the present study. 35.7 % had cerebrovascular risk factors, while 23.5 % had other predisposing factors such as an AVM, an AVF, or a foramen magnum tumor. Predisposing factors in the form of neck trauma, both direct and indirect, were identified in 50 % of cases. The segmental distribution of aneurysms was as follows: three (21.4 %) at CJV 1, one (7.1 %) at CJV 2, four (28.6 %) at CJV 3, two (14.3 %) at CJV 4, and four (28.6 %) isolated to the CJV 5 segment. Of the 6 indirect traumatic aneurysms, 1 (16.7 %) was located at CJV 1, 4 (66.7 %) were located at CJV 3 and 1 (16.7 %) was located at CJV 5. The 1/1 direct traumatic aneurysm (100 %) from the penetrating injury was located at CJV 1. 100 % of cases with cerebrovascular risk factors, the affected vessels were on the dominant side. 42.9 % of cases presented symptoms of a vertebrobasilar stroke. All 14 aneurysms were managed only endovascularly. 85.8 % of patients we implemented flow diverters only. 57.1 % of follow-up cases were completely occluded angiographically, and 42.9 % of cases were near-completely or incompletely occluded at 1, 2.5, and 5-year follow-ups.

CONCLUSIONS

The current article is the first report of a series of vertebral artery aneurysms located in CJ. Herein, the association of vertebral artery aneurysm, hemodynamics, and trauma is well established. We clarified all segments of the CJVA and showed that the segmental distribution of CJVA aneurysms significantly differs between traumatic and spontaneous cases. We showed that treatment with flow diverters should be the mainstay of CJVA aneurysm treatment.

The assessment of the frequency and arrangement of the subsegmental branches of V3 using computed tomography angiography

Background

The frequency and arrangement of the subsegmental branches of the third portion of the vertebral artery (V3) have been assessed in small samples by autopsy, but they have not been assessed by computed tomography angiography (CTA). To determine the frequency and arrangement of subsegmental branches of V3 by CTA and to analyze the interrelationships among frequency, arrangement, sex, and side-to-side.

Methods

First, the radiology records of 668 consecutive patients who underwent cervical or craniocervical CTA scans from October 1, 2017 to October 31, 2019 were retrospectively retrieved. Second, the four demarcation points were ascertained to define the three subsegments by reviewing the resource images, namely, the vertical portion of V3(V3v), horizontal portion of V3(V3h), and extradural portion of V3(V3e). Then, the numerical value and the location of the bifurcating branch in each subsegment of V3 were recorded. Third, the frequency and arrangement of the branches was assessed, and the relationships between sex, laterality and frequency and arrangement were analyzed as well as the interobserver performance.

Results

On the left, 25%, 20.21%, and 6.59% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.05%, 0.00%, and 0.45% were the frequencies of two branches, respectively. On the right, 25.04%, 17.07%, and 6.44% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.04%, 0.3%, and 0.15% were the frequencies of two branches, respectively. There were no differences between the side-to-side and numerical values of the branches according to the t-test (P=0.4341, P=0.7968), and there were no differences between the side-to-side variable, sex variable and number of branches according to the t-test (P=0.4474, P=0.3593). There were no differences between the side-to-side and eight arrangements (permutation of 000; 100; 110; 111; 010; 011; 001; 101) by using the two-sample KS test (P=0.942), and there were no differences between sex and the eight arrangements according to the two-sample KS test (P=0.9973, P=0.8519). The interobserver reliability was excellent (Spearman's ranked correlation: 0.9927).

Conclusions

The frequency and arrangement of V3 subsegmental branches could be displayed by source imaging with CTA, and there were no significant differences according to the sex or side of the individual. It was imperative to acquaint the subsegmental branches before the operation involving V3 in the craniocervical junction to determine the surgical approach and reduce bleeding during the surgical procedures.

Treatment of Extracranial Vertebral Artery Aneurysm with Flow Diversion

BACKGROUND

Aneurysms of the extracranial vertebral artery are rare, and the treatment options are not standardized. We present a case of an extracranial vertebral artery aneurysm treated with flow diversion.

CASE DESCRIPTION

In a 72-year-old woman, computed tomography angiography demonstrated a right extracranial vertebral artery aneurysm. The saccular aneurysm (7.9 × 6.6 mm) was demonstrated on digital subtraction angiography at the V3 segment of the right vertebral artery. A Pipeline embolization device was placed in the diseased parent artery. The patency of the Pipeline embolization device was confirmed at 12-month follow-up.

CONCLUSIONS

Flow diversion is a simple and promising treatment option for a V3 segment aneurysm. Postoperative asymptomatic partial in-stent stenosis is tolerable.

Bilateral Vertebral Artery Aneurysms at the Atlantoaxial Joint Level Causing Recurrent Stroke

Vertebral arteries (VAs) are vulnerable to mechanical stress between the atlas and axis, and subsequent VA dissection can cause posterior circulation infarction. We herein present a rare but informative case of bilateral VA aneurysms that caused recurrent stroke. The localization of the aneurysms and dynamic angiography with neck movement suggested a pathogenesis related to chronic mechanical injury of the VAs, though no skeletal abnormality was detected. The recurrences stopped and both aneurysms shrank after neck collar fixation and after the combination use of antithrombotics. For patients with posterior circulation infarction of unknown origin, a careful evaluation of VAs with physicians paying special attention to the atlantoaxial joint level is therefore recommended.