EXPRESS: Cerebral Microbleed Burden After Aortic and Cardiac Surgery Is Associated With Extracorporeal Circulation Exposure: Evidence From Young Patients With Heritable Connective Tissue Disorders

Background and Purpose: Cerebral microbleeds (CMBs) occur after surgery involving extracorporeal circulation (ECC), though confounding risk factors may obscure this association. Patients with heritable connective tissue diseases (HCTDs) requiring early surgery provide an ideal model to investigate ECC-related CMBs. We aimed to assess CMB prevalence, distribution, and surgical correlates in a genetically confirmed HCTD population. Methods: We retrospectively analyzed 111 HCTD patients with brain magnetic resonance. CMBs number and location were correlated with clinical and surgical data, including procedure frequency, type, and, when available, ECC duration. Results: All 58 patients exposed to surgery under ECC exhibited CMBs, compared to only four surgery-naïve individuals. CMBs showed a predominantly lobar pattern. CMB burden was significantly higher in patients with multiple surgeries and longer ECC duration (P<0.001), whereas valve type and surgical technique showed no association Discussion: In our cohort, CMBs were identified in all individuals with ECC exposure. The absence of significant differences in CMB burden across surgical techniques weakens the hypothesis that CMBs originate solely from metallic microemboli. In young, normotensive patients with HCTDs, ECC exposure was uniformly associated with CMBs, with burden increasing with repeated procedures and ECC duration.