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.
Reference
Title of original paper: Endovascular treatment for basilar trunk artery aneurysm in the flow diverter era: A consecutive series and review of literature
Journal: Chinese Neurosurgical Journal
DOI: 10.1186/s41016-025-00422-6

About Capital Medical University
Capital Medical University, based in Beijing, China, is a leading medical institution dedicated to education, research, and clinical care. It is affiliated with several top-tier hospitals, including Beijing Tiantan Hospital, and is recognized for its strengths in neuroscience, clinical medicine, and public health. The university plays a key role in advancing medical research and training healthcare professionals, contributing to improvements in patient care both in China and internationally.
Website: https://www.bjtth.cn/

About Songyuan Jilin Oilfield Hospital
Songyuan Jilin Oilfield Hospital is a comprehensive medical institution located in Songyuan, in northeastern China. Originally established to serve the Jilin Oilfield workforce, it now provides a wide range of healthcare services to local communities. The hospital offers multidisciplinary care, including neurology, cardiology, and emergency medicine, and supports both clinical practice and research activities. It is also involved in medical education and regional public health efforts. Through its services and collaborations, the hospital plays an important role in healthcare delivery and medical development in the region.

About Dr. Youxiang Li from Capital Medical University
Dr. Youxiang Li is a neurosurgeon at Capital Medical University, affiliated with Beijing Tiantan Hospital and the Beijing Neurosurgical Institute. He specializes in interventional neuroradiology, focusing on the endovascular treatment of intracranial aneurysms and other cerebrovascular diseases. His research centers on minimally invasive techniques, including flow diverter technologies, and their safety and clinical outcomes. Dr. Li has authored multiple peer-reviewed studies and contributes to advancing neurointerventional care, particularly for complex and rare brain vascular conditions.

About Dr. Wei Feng from Songyuan Jilin Oilfield Hospital
Dr. Wei Feng is a neurosurgeon affiliated with Songyuan Jilin Oilfield Hospital in Songyuan, China. He is involved in the clinical management of neurological and cerebrovascular conditions, with a focus on the diagnosis and treatment of intracranial aneurysms. His work includes participation in research on endovascular therapies and patient outcomes, contributing to advancements in minimally invasive neurointerventional techniques. Through both clinical practice and academic collaboration, he supports the development of neurovascular care in regional healthcare settings.

Funding information
This work was supported by the Beiling Gold-Bridge Project (grant number: ZZ21060).