Posterior Circulation Aneurysms

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.

The Vertebrobasilar Trunk and Its Anatomical Variants: A Microsurgical Anatomical Study

BACKGROUND

The trunk of the basilar artery has not been included in microanatomy studies. Anatomical variants of the perforant branches of the vertebrobasilar trunk and their relationship with neural structures are very important in surgical approaches. Surgical dissection for the treatment of vascular lesions requires a perfect knowledge of the microsurgical anatomy.

METHODS

We conducted a descriptive analysis of 50 brains, which were fixed with formalin at 10% for 2 weeks, and the arterial system was injected with colored latex. After microsurgical dissection, it was divided into three segments: the lower portion went from the anterior spinal artery to the anteroinferior cerebellar artery, the middle segment was raised from the upper limit of the lower portion to the origin of the superior cerebellar artery, and the upper segment ranged from the previous portion until the origin of the posterior cerebral artery.

RESULTS

The basilar artery had an average length of 30 mm. The average diameter at its junction with the vertebral arteries was 4.05 mm. The average middle segment was 3.4 mm in diameter and 15.2 mm in length. The diameter of the upper segment was 4.2 mm, and its average length was 3.6 mm. The average number of bulbar arteries was three, and their average diameter was 0. 66 mm. The number of caudal perforator arteries were five on average, with a diameter of 0.32 mm. We found three rare cases of anatomical variants in the vertebra-basilar junction.

CONCLUSIONS

The basilar artery emits penetrating branches in its lower, middle, and upper portions. The origin of penetrating branches was single or divided after forming a trunk. However, we observed long branches from perforant arteries.

Efficacy and Safety of Extracranial-Intracranial Bypass Surgery for Posterior Circulation Aneurysms: A Systematic Review and Single-Arm Meta-Analysis

OBJECTIVE

Treating complex posterior circulation aneurysms poses challenges, and extracranial to intracranial (EC-IC) bypass techniques are potential therapeutic options. However, the safety and efficacy of this approach for posterior circulation aneurysms remain unclear. The study's objective was to assess the safety and efficacy of EC-IC bypass in these aneurysms.

METHODS

Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we conducted a systematic review on EC-IC revascularization for posterior circulation aneurysms. Included studies had at least 4 patients and reported data on mortality, patency, complications, or clinical outcomes. Favorable clinical outcomes were defined as modified Rankin Scale below 3 or Glasgow Outcome Scale above 3, and complications were any issues related to the bypass procedure.

RESULTS

From 3036 articles reviewed, 22 studies involving 196 patients who underwent 210 EC-IC bypass procedures for posterior circulation aneurysms were selected. The median follow-up period of 14 studies was 31.66 months (6-61 months). Final follow-up indicated a high bypass patency rate of 96% [95% confidence interval [CI]: 91%-100%; I2 = 12%], with a mortality rate of 5% [95% CI: 1%-9%; I2 = 0%]. Additionally, 83% [95% CI: 70%-96%; I2 = 77%] of patients showed good outcomes at the last follow-up. Complications were observed in 40% [95% CI: 26%-55%; I2 = 80%]. Heterogeneity was associated with specific studies.

CONCLUSIONS

EC-IC bypass procedures are a viable treatment option for posterior circulation aneurysms, with high bypass patency rates and favorable clinical outcomes. However, complications, especially neurological deficits, exist. Open revascularization remains essential for neurovascular surgeons dealing with complex aneurysms.