Imaging for Predicting Hemorrhagic Transformation of Acute Ischemic Stroke-A Narrative Review.

Hemorrhagic transformation is caused by extravasation of blood products from vessels after acute ischemic stroke. It is an undesirable and potentially devastating complication, which occurs in 10%-40% of clinical cases. Hemorrhagic transformation is classified into four subtypes based on European cooperative acute stroke study II. Predicting hemorrhagic complications at presentation can be useful life saving/altering decisions for the patient. Also, understanding the mechanisms of hemorrhagic transformation can lead to new treatments and intervention measures. We highlighted various imaging techniques that have been used to predict hemorrhagic transformation. Specifically, we looked at the usefulness of perfusion and permeability imaging for hemorrhagic transformation. Use of imaging to predict hemorrhagic transformation could change patient management that may lead to the prevention of hemorrhagic transformation before it occurs. We concluded that the current evidence is not strong enough to rely on these imaging parameters for predicting hemorrhagic transformation and more studies are required.

Quantifying candidate volume for endovascular therapy for acute ischemic stroke: a retrospective chart review.

BACKGROUND: Endovascular therapy is the new standard of care for certain patients with acute ischemic stroke. We aimed to determine whether procedural volumes at an academic health sciences centre in northeastern Ontario exceeded the minimum of 20 procedures annually to support establishment of an endovascular therapy centre and thus improve regional access to this type of care. METHODS: We conducted a retrospective chart review at Health Sciences North, a regional stroke centre for northeastern Ontario that currently does not offer endovascular therapy for patients with acute ischemic stroke. Medical records and neurovascular imaging results for patients with a discharge diagnosis of cerebral infarction who were seen by the stroke on-call team at Health Sciences North between May 1, 2016, and Apr. 30, 2017, were retrospectively examined in accordance with criteria of the ESCAPE trial to identify potential candidates for endovascular therapy. The number of candidates was extrapolated to include patients discharged with cerebral infarction from referral centres within a 2-hour transport radius from the study institution. RESULTS: Of 71 patients who met the inclusion criteria, 9 were identified as candidates. Of the 71 cases reviewed, 62 (87%) presented within the window for administration of recombinant tissue plasminogen activator of 4.5 hours from symptom onset, 66 (93%) within the endovascular therapy window of 6 hours and 69 (97%) within the extended endovascular therapy window of 12 hours. Expanding these estimates to include regional referral centres, we conservatively estimated that Health Sciences North has the potential to perform 22 or 23 procedures annually. INTERPRETATION: The projected annual number of procedures met the minimum requirement to maintain competency. Establishing Health Sciences North as a centre for endovascular therapy could be an important step in improving equity in stroke outcomes across northeastern Ontario.