The Source for Neurovascular News and Education

May 22, 2019


These patients may benefit most from rapid recanalization, a small German study suggests.


Lesion growth following acute ischemic stroke occurs more rapidly during the hyperacute phase, according to research published online November 21, 2018, ahead of print in Stroke. There is also a more variable rate of lesion growth during this phase, suggesting a need to identify growth patterns in individual patients and tailor treatment strategies accordingly.


“In the clinical context, hyperacute presentation might suggest ‘having more time’ to treat a patient with acute ischemic stroke, based on formerly existing rigid time window limitations (ie, 4.5 hours for lysis, 6 hours for thrombectomy),” lead author Gabriel Broocks, MD (University Medical Center Hamburg-Eppendorf, Hamburg, Germany), told Neurovascular Exchange via email.


“Our study aimed to investigate whether the same time from imaging to vessel recanalization leads to higher lesion growth in patients in the hyperacute time window, based on observations that lesion growth is best characterized as logarithmic/nonlinear,” he explained.


For the study, Broocks and colleagues identified 51 patients with ischemic stroke who underwent successful endovascular recanalization and underwent initial multimodal CT as well as follow-up CT after 24 hours. The patients were divided into two groups according to their median time from symptom onset to imaging.


Among all patients, the median time from onset to imaging was 1.85 hours. Overall, 25 patients met criteria for the hyperacute group (time from symptom onset to imaging < 1.85 hours), and the remaining 26 patients met criteria for the acute group (time from symptom onset to imaging ≥ 1.85 hours).


The investigators observed no significant differences between the two groups in ASPECTS on admission or in time from imaging to recanalization.


Similarly, the two groups did not differ with respect to volumetric difference in lesion size. “Levene’s test revealed significant differences in variances, meaning that the range in lesion growth was much higher in hyperacute patients,” pointed out Broocks.


Lesion Features and Growth



(n = 25)


(n = 26)

P Value

Mean ASPECTS at Baseline




Time From Imaging to Recanalization, hours




Mean (SD) Lesion Growth

2.7 (2.3)

1.6 (1.3)


Mean (SD) Volumetric Difference, mL

26.6 (43.2)

17.2 (26.3)



For every passing hour after onset, ASPECTS lesion growth was reduced by 0.4.


Faster, More Variable Growth Rate


“Patients in the hyperacute phase showed increased lesion growth from imaging to recanalization, suggesting a particular benefit of faster recanalization times in this group of stroke patients,” noted Broocks.


As a result, he recommended: “Patient care should stop focusing on any rigid time windows but triage every patient individually for treatment. Patients with high early lesion growth rates might not be eligible for time-consuming transportation to a tertiary-care center, but require immediate vessel recanalization.”


“The motto ‘time is brain’ should be especially paid attention to in patients with a hyperacute presentation,” he continued. Broocks speculated that tools such as machine-learning algorithms might be used in the future to predict outcome and lesion growth more precisely and “to estimate the dynamic component in each patients’ individual lesion growth evolution.”


Looking to the future, he noted, it will be important to determine what the clinical implications are of having rapid- or slow-growing lesions and to identify such growth patterns early enough to adjust the intervention appropriately.



Broocks G, Rajput F, Hanning U, et al. Highest lesion growth rates in patients with hyperacute stroke: when time is brain particularly matters. Stroke. 2018;Epub ahead of print.



Broocks reports no relevant conflicts of interest.