Basilar trunk artery aneurysms (BTAs) are among the rarest and most complex types of brain aneurysms, occurring in a critical vessel that supplies blood to the brainstem. Because of their location and low incidence, there has been limited research guiding how best to treat them, leaving neurosurgeons with few large datasets to inform clinical decisions.
A new study led by Dr. Youxiang Li from Beijing Tiantan Hospital, Capital Medical University, and Dr. Wei Feng from the Department of Neurosurgery at Songyuan Jilin Oilfield Hospital, China, helps address this gap by providing one of the most comprehensive analyses of endovascular treatment (EVT) outcomes for BTAs in the modern "flow diverter" era. The research, published on March 5, 2026, in the Chinese Neurosurgical Journal , examines treatment approaches, complication rates, and long-term outcomes in patients undergoing minimally invasive procedures.
"Our findings show that most patients with these rare aneurysms can be treated effectively using endovascular techniques, with encouraging long-term recovery," said Dr. Li.
The researchers conducted a retrospective analysis of 2,759 aneurysm patients treated between 2018 and 2022, identifying 37 cases of basilar trunk artery aneurysms. They also reviewed published studies from 2013 to 2024 to place their findings in a broader clinical context.
Patients in the study underwent a range of minimally invasive procedures, including simple coiling, stent-assisted coiling, and flow diverters, devices designed to redirect blood flow away from the aneurysm. Stent-assisted coiling was the most common treatment, used in just over half of cases, while flow diverters were employed in nearly 30%, particularly for more complex or larger aneurysms.
The results were largely positive. At follow-up imaging, about 72% of patients achieved complete aneurysm occlusion, meaning the aneurysm was fully sealed off, while nearly 19% had near-complete occlusion. Clinically, about 89% of patients had favorable outcomes, defined as minimal or no disability.
"These outcomes are encouraging, especially given the complexity and risks associated with aneurysms in this location," said co-author Dr. Wei Feng. "These results demonstrate that modern endovascular approaches can achieve high occlusion rates alongside favorable functional outcomes."
However, the study also highlights important risks. Procedure-related complications occurred in around 11% of patients, including both hemorrhagic and ischemic events. Two patients died during follow-up, underscoring the seriousness of the condition.
Notably, the size of the aneurysm emerged as a key factor influencing risk. Larger aneurysms were associated with a higher likelihood of complications and poorer outcomes, although these associations did not reach statistical significance.
"Larger aneurysms appear to pose additional challenges during treatment," said Dr. Li. "This emphasizes the importance of individualized treatment planning and careful monitoring."
The authors note that while traditional techniques such as coiling remain widely used, newer technologies like flow diverters are playing an increasing role, particularly in complex cases such as large or fusiform aneurysms.
Despite its strengths, the study has limitations. It is based on a relatively small sample size from a single center, reflecting the rarity of the condition, and its retrospective design may introduce bias. The authors also point out that longer follow-up and larger, multicenter studies are needed to confirm their findings.
Despite these limitations, the study provides important insights into a poorly understood condition and supports the growing role of minimally invasive approaches in its management.
The authors noted that although BTAs remain challenging, effective treatment is possible in the majority of cases, and future research should focus on optimizing strategies for higher-risk patients, particularly those with larger aneurysms.
