Interventional Radiology · Neurointervention · eTICI 2019

Expanded TICI Reperfusion Grades

The expanded Treatment in Cerebral Ischaemia scale grades angiographic tissue reperfusion after endovascular stroke treatment. It subdivides the broad mTICI 2b category to distinguish moderate, substantial and near-complete reperfusion.

Purpose

To standardise final angiographic assessment of downstream tissue reperfusion after endovascular treatment of acute ischaemic stroke.

eTICI grade	Reperfused target territory	Angiographic interpretation
0	0%	No reperfusion of the downstream target territory
1	0%	Thrombus reduction or limited passage beyond the original occlusion without reperfusion of distal arteries
2a	1–49%	Partial reperfusion of less than half of the target territory
2b50	50–66%	Reperfusion of at least half but less than two-thirds of the target territory
2b67	67–89%	Substantial reperfusion, but residual unreperfused territory remains
2c	90–99%	Near-complete reperfusion with only a small residual perfusion defect
3	100%	Complete reperfusion of the target territory

How to use it

Grade the proportion of the original downstream target territory that is reperfused on the final angiographic run.
The scale measures tissue reperfusion, not merely reopening or recanalisation of the previously occluded artery.
eTICI subdivides the broad mTICI 2b range into 2b50, 2b67 and 2c, providing greater discrimination between 50% and near-complete reperfusion.
Increasing eTICI grades correlate with progressively better functional outcomes; conventional technical success is commonly reported as grade 2b50 or better.
Record the final grade and, when relevant, the first-pass grade because the number of thrombectomy attempts is not represented by the classification.

Common mistake

Do not assign eTICI 3 simply because the proximal target artery has reopened; any residual distal territorial perfusion defect prevents a grade of complete reperfusion.

Exam pearl

eTICI 2c means 90–99% near-complete reperfusion, whereas eTICI 3 requires 100% reperfusion of the original target territory.

Viva questions

What does the expanded TICI scale assess?: It assesses the proportion of the original downstream target territory that has been reperfused on angiography after endovascular stroke treatment.
Enumerate the expanded TICI grades.: The grades are 0, 1, 2a, 2b50, 2b67, 2c and 3.
How are eTICI 0 and eTICI 1 differentiated?: Both have no distal tissue reperfusion. Grade 0 indicates no reperfusion, whereas grade 1 indicates some thrombus reduction or limited passage beyond the original occlusion without reperfusion of distal arteries.
What percentage of territorial reperfusion defines eTICI 2a?: eTICI 2a represents reperfusion of 1–49% of the original target territory.
How are eTICI 2b50 and 2b67 differentiated?: eTICI 2b50 represents 50–66% reperfusion, while eTICI 2b67 represents 67–89% reperfusion.
What is the difference between eTICI 2c and eTICI 3?: eTICI 2c is near-complete reperfusion of 90–99% of the target territory. eTICI 3 requires complete, 100% territorial reperfusion.
Why was the expanded TICI scale introduced?: The conventional mTICI 2b category covered a wide range of reperfusion. eTICI subdivides this range into 2b50, 2b67 and 2c, allowing more precise angiographic and outcome assessment.
What is the common pitfall when assigning eTICI 3?: Reopening the proximal target artery is not sufficient. Any residual distal territorial perfusion defect means that complete eTICI 3 reperfusion has not been achieved.