Systematic tissue sampling in aneurysm surgery: From necessity and concept to a safe, reproducible technique-A...

Research on intracranial aneurysm (IAs) emphasizes the role of flow-induced and neuroinflammation-driven vascular remodelling in aneurysm progression and rupture. However, tissue access for histo-molecular analysis remains limited, particularly with the rise of endovascular techniques. This study aims to establish systematic criteria for IA tissue sampling and preservation in clinical practice.

In this retrospective study, adult patients undergoing IA surgery had systematic sampling of the aneurysmal wall, meninges, middle meningeal artery, and superficial temporal artery. Histological analysis was performed to assess tissue integrity, followed by pre-analysis using housekeeping genes expression to evaluate the feasibility of RT-qPCR analyses. Clinico-radiological data, including sampling-related complications were reviewed. A statistical comparison was made between ruptured and unruptured aneurysm groups.

Aneurysms of the middle cerebral artery (MCA) accounted for over 60% in both groups. As expected, in ruptured cases, morbidity and mortality were significantly higher than in unruptured cases (p < 0.001; p = 0.043). No major complications could be directly attributed to sampling. Sampling success rates for the aneurysmal wall reached 97% in both groups, and around 80% for other tissues (STA, MMA, DM). Histopathological analysis of the aneurysmal wall was completed in 85% of unruptured cases and 83% of ruptured cases, indicating a depth limit of >3 mm for aneurysm sampling. Housekeeping gene expression was observed in all samples, without restriction based on aneurysm depth.

This study proposed criteria for safe and reproducible MCA aneurysm tissue sampling in routine clinical practice. These findings could support the creation of a national French vascular biobank, fostering further translational research.