Diffusion-weighted magnetic resonance imaging lesions after repair of acute type A aortic dissection: association with neurocognitive outcomes†‡.

Objectives: We sought to analyse the preoperative status of arch vessels by postoperative diffusion-weighted magnetic resonance imaging (DWI) as a potential surrogate marker for cerebral thromboembolism and its relationship to neurocognitive outcomes.

Methods: Preoperative computed tomography (CT) and postoperative DWI were available for 50 patients who received surgery for acute type A aortic dissection. Two radiologists evaluated CT and DWI scans. Mini-mental status examinations (MMSE) were performed on the same day with DWI.

Results: Mean age of participants was 57 ± 14 years. MMSE and DWI were performed 6 ± 3 days after surgery. New cerebral embolisms were evident in 35 of 50 patients (70%) and often occurred as multiple lesions (28/35, 80%; range 2-21). Among patients with multiple lesions, 23 (66%) were clinically silent. Pathological lesions at the origin of the arch vessels correlated with the number and volume of new DWI lesions (P < 0.05). Degree of neurocognitive dysfunction tested by MMSE was negatively associated with age (r = -0.48, P < 0.0001) and left-sided DWI lesion number and volume (r = -0.74, P < 0.0001; r = -0.707, P < 0.0001).

Conclusions: DWI revealed new cerebral embolisms in 70% of patients following surgery for acute type A aortic dissection. Lesion number and volume significantly correlated with pathological status of arch vessels. MMSE was representative of left-sided lesions.