Vulnerable Thrombus as a Cause of Spinal Cord Ischemia After Thoracic Endovascular Aortic Repair: Tokai Multicenter Study.

BACKGROUND

Spinal cord ischemia (SCI) is a serious complication after thoracic endovascular aortic repair (TEVAR). However, the pathophysiology of SCI after TEVAR is not fully understood. The aim of this study was to evaluate the association between the density of mural thrombi in the descending thoracic aorta (DTA) and SCI.

METHODS

Clinical data from all patients who underwent TEVAR at 9 institutions between October 2008 and December 2022 were retrospectively reviewed. At each institution, all patients who developed SCI were included, and an equal number of patients without SCI were included in the control group. This approach aimed to minimize the influence of treatment length, which is widely recognized as one of the most significant risk factors for SCI. We analyzed preoperative computed tomography angiography (CTA) images. We used the plaque analysis module of the workstation to distinguish the sites of mural thrombi distributed throughout the DTA. The volume of each defined tissue category was automatically calculated. A low-density thrombus (LDT) was < 30 Hounsfield unit (HU), an intermediate-density thrombus was ≥ 30 but < 150 HU, and a high-density thrombus was > 150 HU.

RESULTS

Thirty-two patients with SCI and 32 patients without SCI were included in the study. Univariate analysis revealed that total thrombus volume (P = 0.032) and LDT volume (P = 0.006) were significantly higher in SCI group. Multivariate analysis revealed that the LDT volume was the only predicter of SCI.

CONCLUSIONS

We observed that LDT in the DTA is associated with SCI after TEVAR. This data indicated that the mechanism of SCI after TEVAR may be related to embolism of vulnerable thrombi in the DTA.