Endovascular treatment of supraclinoid internal carotid artery aneurysms

A New Classification of Anterior Choroidal Artery Aneurysms and Its Clinical Application

Background and Purpose: The aim of this study was to compare the different subtypes of anterior choroidal artery (AChoA) aneurysm based on a new classification and to analyze the risk factors according to individual endovascular treatment (EVT).

Methods: In the new classification, AChoA aneurysms are classified into independent type (I type) and dependent type (II type) based on the relationship between the AChoA and the aneurysm. II type aneurysms have three subtypes, IIa (neck), IIb (body), and IIc (direct). We retrospectively analyzed 52 cases of AChoA aneurysm treated in our center between 2015 to 2019. There were 13 (25.0%) I type aneurysms, 24 (46.2%) IIa aneurysms, 15 (28.8%) IIb aneurysms, and no IIc type; 28 cases had a subarachnoid hemorrhage. According to our preoperative EVT plan for the different subtypes: II type should achieve Raymond-Roy Occlusion Class 1 (RROC 1) where possible. To protect the AChoA, it is best to preserve the neck of the IIa type aneurysms (RROC 2), and RROC 3 is enough for IIb type.

Results: Ten asymptomatic cases with minimal aneurysms were treated conservatively. Of the other cases, 42 were treated with individualized EVT (26 with a simple coil, 6 with balloon-assisted coiling, 7 with stent-assisted coiling, and 3 by flow diverter. Different subtypes had different RROC (Z = 14.026, P = 0.001). IIb type aneurysms (χ² = 7.54, P = 0.023) were one of the factors related to temporary or permanent AChoA injury during surgery. Overall, two patients (IIa = 1, IIb = 1) developed contralateral hemiparesis.

Conclusions: The new classification diagram clearly shows the features of all types of AChoA aneurysm and makes EVT planning more explicit. The II type (particularly IIb) was a potential risk factor for AChoA injury.

Efficacy and Safety of Willis Covered Stent for Treatment of Internal Carotid Artery Aneurysms

OBJECTIVE

The purpose of this study was to evaluate the clinical and short-term outcome of patients who underwent covered stent treatment for internal carotid artery aneurysms.

METHODS

Twelve cases patients with internal carotid artery aneurysms were treated with Willis covered stents during the period from December 2010 to January 2016. The guiding catheter was placed as high as possible to facilitate the delivery of the covered stent system.

RESULTS

Covered stent placement was successful in 11 of 12 case patients (91.6%), embolization was successful in 11 of 12 patients (91.6%), the treatment in 1 patient of 12 cavernous aneurysms patients was performed covered stents +ONYX + plastic coil embolization, and the other was used Willis covered stents. The results indicated that only 1 of 12 patients underwent postoperative massive cerebral infarction, but was successfully rescued. The angiographic following-up of patients using covered stent suggested that 12 cases patients were complete occlusion and the parent artery patency. Clinical follow-up results also demonstrated that clinical neurologic symptoms fully recovered in 11 of 12 cases patients, another case improved and were not aggravated in any patient before discharge and had aggravated symptoms.

CONCLUSION

Willis covered stents are effective for treatment of internal carotid artery aneurysms with good safety and short-term outcomes.

Endovascular treatment of blister aneurysms

Blister aneurysms are rare cerebrovascular lesions for which the treatment methods are reviewed here, with a focus on endovascular options. The reported pathogenesis of blister aneurysms varies, and hemodynamic stress, arterial dissection, and arteriosclerotic ulceration have all been described. There is consensus on the excessive fragility of blister aneurysms and their parent vessels, which makes clipping technically difficult. Open surgical treatment is associated with high rates of complications, morbidity, and mortality; endovascular treatment is a promising alternative. Among endovascular treatment options, deconstructive treatment has been associated with higher morbidity compared with reconstructive methods such as direct embolization, stent- or balloon-assisted direct embolization, stent monotherapy, and flow diversion. Flow diversion has been associated with higher technical success rates and similar clinical outcomes compared with non–flow diverting treatment methods. However, delayed aneurysm occlusion and the need for antiplatelet therapy are potential drawbacks to flow diversion that must be considered when choosing among treatment methods for blister aneurysms.