Introduction: Improvement in cerebral perfusion post endovascular treatment of vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH) is typically assessed by comparison of major vessel diameters on digital subtraction angiography (DSA). In this report we sought to assess relative changes in cerebral blood flow by computational DSA transit time (TT) analysis in patients with cerebral vasospasm before/after endovascular treatment.
Methods: A cohort of 28 patients with aSAH were included. Demographic variables, neurological status, Hunt&Hess grade(H&H) were collected. We developed a method to measure DSA TT by color-coded reconstruction based on DSA contrast intensity. Regions of interest were chosen over major cerebral vessels (Figure 1). The estimated TT included Time-To-Peak (TTP) from 0-100% intensity (TTP0-100), TTP from 25-100% (TTP25-100), and TT from 100-10% (TT100-10). Paired student t-test was used to compare TT before and after vasospasm treatment.
Results: There were 85 treatment sessions (44-left ICA ; 41-right ICA). All sessions included vasodilator infusion +/-transluminal balloon angioplasty (33 sessions). There was statistically significant reduction in all TT before and after treatment respectively; M1-TTP0-100, (2.35 vs.2.02 sec, p=0.001), M1-TTP25-100, (2.41 vs.2.12sec, p=0.001), M1-TT100-10 (5.58 vs.4.66sec, p=0.0001) and A1: A1-TTP0-100, (2.37 vs.2.01sec, p=0.001), A1-TTP25-100, (2.4 vs.2.07sec, p=0.001) and in A1-TT100-10 (5.58 vs.4.69sec, p=0.012). Post treatment TTs were comparable to the admission TTs (H&H 1-2 grade). The TT changes corresponded to neurological improvements in all patients, except patients with established ischemic stroke (4 sessions) and poor H&H grades (16 sessions). No correlation was seen between angiographic vasospasm severity (mild/moderate/severe) and TT.
Conclusions: The DSA TT correlated with improvements in neurological status in patients with clinical vasospasm. TT might reflect a better way to assess vasospasm severity and response to treatment as compared to vessel diameter. This method may serve as a useful indirect technique for cerebral blood flow assessment in the angiography suite.
Patient Care: This method may serve as useful indirect technique for cerebral blood flow assessment in angiography suite in patients with aSAH
Learning Objectives: By the conclusion of this session, participants should be able to describe the importance of the cerebral blood flow assessment in angiography suite in patients with aSAH and to identify the lack of correlation between vessel diameter measured on DSA and cerebral blood flow status.