Nirali Vora, MD

Altinbas A, Algra A, Bonati LH, Brown MM, Kappelle LJ, de Borst, et al. Periprocedural Hemodynamic Depression Is Associated With a Higher Number of New Ischemic Brain Lesions After Stenting in the International Carotid Stenting Study-MRI Substudy. Stroke. 2013

Carotid stenting lost the revascularization battle to carotid endarterectomy largely due to increased 30-day risk of stroke and death, as demonstrated in ICSS (international carotid stenting study). In an MRI sub-study of ICSS where pre- and post-procedural MRIs were compared, stenting (CAS) patients had more (3x) new DWI lesions compared to the endarterectomy (CEA) group. What was the role of hypoperfusion among these patients?

In this analysis of the ICSS-MRI substudy, Bonati et al counted the number and volume of new DWI lesions POD#1-3 and looked for associations with “hemodynamic depression.” This was defined as periprocedural bradycardia, asystole, or hypotension requiring treatment. The group found that there were more DWI lesions among patients with hemodynamic depression undergoing CAS rather than CEA.  There was no difference in DWI lesion volume. The pattern of the lesions may be available in the supplement, but not available to me for review. There were no functional outcomes studied. 

Why wasn’t the effect of hypoperfusion seen among CEA patients? It’s unclear to me, but perhaps this is a compounded effect on top of the intrinsic risk of stroke from the CAS procedure. Other determinants of stroke may also be present (but not studied) since the number of patients undergoing CAS with higher DWI lesions was more than those who had hemodynamic depression.

Despite limitations to this study, the results do re-emphasize the importance of maintaining blood pressures during and after CAS. Though I don’t know when the exact hypoperfusion is happening, I wonder if standardizing use of neuroanesthesia with intraoperative monitoring would help ensure adequate functional perfusion during the procedure itself. Afterwards, we and our vascular surgery colleagues, must ensure stringent monitoring of MAPs and attention to keeping the patient closer to their pre-op baseline. There are too many cases of both CEA and CAS where we walk in on post-op stroke codes and the MAP is >60 but the patient lives closer to MAP>80.  

What do you do at your institution to avoid post-procedure hypotension in your carotid revascularization patients?