Repeated Clot Retrieval Attempts After Ischemic Stroke Linked to Worse Outcomes

June 25, 2021
Increasing number of clot retrieval attempts in acute stroke is correlated with an increased emboli to new territory and greater infarct growth volume, affecting functional outcome even when successful recanalization is achieved, according to a study published in the journal Neurology. “These findings highlight the need for a study to determine the appropriate strategy to use when the first attempt at retrieving a blood clot is unsuccessful, since each additional attempt reduced the odds of a favourable outcome,” said Wagih Ben Hassen, MD, French National Institute for Health and Medical Research, Paris, France. The study involved 419 patients who had an ischaemic stroke and had successful recanalization. There was 1 clot retrieval attempt for 224 patients, 2 attempts for 107 patients, 3 attempts for 49 patients, and ≥4 attempts for 39 people. But clearing the clots took one try for 224 people, two tries for 107 people, three tries for 49 people and four or more tries for 39 people. Emboli to new territory occurrence was strongly correlated with increasing clot retrieval attempts. Emboli to new territory occurred in 23 patients within 24 hours after stroke. Of these patients, 2 had 1 clot retrieval attempt, 3 had 2 attempts, 7 had 3 attempts, and 11 had ≥4 attempts. For those with 1 attempt at clot removal, the average infarct growth rate was 10 ml, for 2 tries it was 16 ml, for 3 attempts it was 21 ml, and ≥4 attempts was 25 ml. Unfavourable functional outcome (3-month modified Rankin Score >2) increased with each additional clot retrieval attempts. Overall, 57% had no or mild disability. Of those with one try at retrieval, 62% had no or mild disability, compared with 55% of those with 2 attempts, 49% of those with 3 attempts, and 42% of those with ≥4 more attempts. In multivariable linear analysis, infarct growth was independently associated with clot retrieval attempts (P = .03) and emboli to new territory (P = .03). “Achieving successful removal of blood clots and clearing these blood vessels with the fewest number of attempts, and ideally with a single pass, appears to be the new goal,” said Dr. Hassen. “This underlines the need to develop a new generation of devices designed to increase the rate of complete success at the first attempt.” A limitation of the study is that while researchers adjusted for other factors that could affect growth in the amount of brain damage 24 hours after the stroke, the small number of people in some groupings could affect this analysis. Reference: https://n.neurology.org/content/early/2021/06/23/WNL.0000000000012321 SOURCE: American Academy of Neurology