Stroke: Frequency and distribution of neoischemic brain lesions on brain MRI after aortic arch surgery

The study focused on the frequency and distribution
of neo-ischemic encephalopathy detected by diffusion-weighted imaging in brain magnetic resonance imaging after aortic arch surgery.

This randomized, controlled ACE (Brain Protection Assessment for Aortic Surgery) CardioLink-3 trial compared the safety and efficacy
of sternal and axillary artery intubation during elective proximal aortic arch surgery.
Participants underwent pre- and postoperative magnetic resonance imaging
.
New ischemic lesions are defined as lesions visible postoperatively, rather than preoperatively diffusion-weighted imaging
.

The results showed that of the 111 trial participants, 102 had complete MRI data
.
A total of 391 new ischemic foci
were observed on diffusion-weighted imaging of 71 patients (70%).
The average number of lesions in patients with ischemic lesions was (5.
5±4.
9), and the number of lesions in the right hemisphere (2.
9±2.
0) and left hemisphere (3.
0±2.
3) was comparable (P=0.
49).

Half of the new lesions are in the middle cerebral artery region; 63% of the cohort had ischemic lesions in the anterior circulation, 49% in the posterior circulation, 42% in both, and 20% in the watershed region
.
All diffusion-weighted imaging lesions show widespread cerebellar involvement
.

More severe white matter hyperintensity on preoperative MRI (odds ratio, 1.
80 [95% CI, 1.
10-2.
95]; P = 0.
02) and lower nasopharyngeal temperature during surgery (odds ratio per 1°C, 1.
15 [95% CI, 1.
00-1.
32]; P=0.
05) related to the emergence of new ischemic lesions; older age (risk ratio per additional year, 1.
02 [95% CI, 1.
00-1.
04]; P = 0.
03) and lower nasopharyngeal temperature (risk ratio per 1°C reduction, 1.
06 [95% CI, 1.
00-1.
14]; P=0.
06) is related to
the number of lesions.

In summary, new ischemic encephalopathy is common in patients undergoing elective proximal aortic arch surgery and mainly involves the middle cerebral artery region or cerebellum
.
Underlying small-vessel disease, lower temperature floor during surgery, and advanced age are risk factors
for perioperative ischaemic lesions.

References:

Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE CardioLink-3 Randomized Trial