Objective: Although stroke guidelines recommend antiplatelets be started 24 hoursafter tissue plasminogen activator (tPA), select mechanical thrombectomy (MT)patients with luminal irregularities or underlying intracranial atherosclerotic diseasemay benefit from earlier antiplatelet administration. Methods: We explore the safety of early (< 24 hours) post-tPA antiplatelet use byretrospectively reviewing patients who underwent MT and stent placement for acuteischemic stroke from June 2015 to April 2018 at our institution. Results: Six patients met inclusion criteria. Median presenting and pre-operativeNational Institutes of Health Stroke Scale scores were 14 (Interquartile Range [IQR]5.5-17.3) and 16 (IQR 13.7-18.7), respectively. Five patients received standard intravenous(IV) tPA and one patient received intra-arterial tPA. Median time from symptomonset to IV tPA was 120 min (IQR 78-204 min). Median time between tPA and antiplateletadministration was 4.9 hours (IQR 3.0-6.7 hours). Clots were successfullyremoved from the internal carotid artery (ICA) or middle cerebral artery (MCA) in 5patients, the anterior cerebral artery (ACA) in one patient, and the vertebrobasilarjunction in one patient. All patients underwent MT before stenting and achievedthrombolysis in cerebral infarction 2B recanalization. Stents were placed in the ICA(n=4), common carotid artery (n=1), and basilar artery (n=1). The median time fromstroke onset to endovascular access was 185 min (IQR 136-417 min). No patientsexperienced symptomatic post-procedure intracranial hemorrhage (ICH). Medianmodified Rankin Scale score on discharge was 3.5. Conclusions Antiplatelets within 24 hours of tPA did not result in symptomatic ICHin this series. The safety and efficacy of early antiplatelet administration after tPA inselect patients following mechanical thrombectomy warrants further study.

Objective: Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality. Methods: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality. Results: A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time. Conclusions We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.