Impact of Multivessel Angiogram on Radiation Exposure and Costs After Thrombectomy

Introduction Mechanical thrombectomy is the current gold standard for the treatment of large vessel occlusions in ischemic stroke. However, the role of performing a multivessel diagnostic cerebral angiogram following thrombectomy remains unclear. Prior studies have examined how often these angiograms identify new pathology not visualized on initial head and neck computed tomography angiography (CTA). In contrast, limited data is available regarding the associated risks exposure and cost‐effectiveness of performing a multivessel diagnostic cerebral angiogram after mechanical thrombectomy. Methods A retrospective chart review was performed on patients that had uncomplicated mechanical thrombectomy performed for acute ischemic stroke between July 2020 and June 2023 at a major comprehensive stroke center. Uncomplicated mechanical thrombectomy was defined as not requiring balloon angioplasty or stenting. Patients that did not have a pre‐procedure CTA were excluded from the study. Significant vascular findings that were not seen on pre‐procedure CTA, patient demographics, total procedure time, total radiation exposure, vessels visualized intracranially, total estimated relative value units (RVU), and complications were documented for analysis. Multivessel cerebral angiograms were categorized based on the number of intracranial vessels visualized which included the bilateral internal carotid and vertebral arteries. Results Of the patients reviewed for this study, 251 patients met criteria and were included in analysis. Average age was 67.7 years. Average NIH was 14.6. The patient sample was 51.4% females. Eighty‐eight (35%) patients received thrombolytics prior to mechanical thrombectomy. Average procedure time was 47 minutes and 14 seconds. Average radiation was 356275.6 mGycm 2 . Average RVU per procedure was 21. Ten patients had significant vascular findings that were not identified on pre‐procedure CTA; however, only four of these findings involved vessels that were not the target of the mechanical thrombectomy. Six patients had aneurysms greater than 3mm in size, two patients had significant missed vessel occlusions, one patient had a significant high‐grade stenosis, and one patient had a dural arteriovenous fistula. There were 97 patients who received single vessel mechanical thrombectomy without further diagnostic angiogram of any other intracranial vessels. A further diagnostic angiogram of at least one additional intracranial vessel was performed in 154 patients. Of these, 17 patients had visualization of two intracranial vessels, 123 patients had visualization of three intracranial vessels, and 14 patients had visualization of four intracranial vessels. No complications were associated with performing additional multivessel diagnostic cerebral angiography. An analysis of variance (ANOVA) found that patients that had multivessel diagnostic cerebral angiograms after mechanical thrombectomy had significantly increased radiation exposure (p = 0.005) and cost significantly more RVUs on average (p= 2.95E‐88). Patients that had multivessel diagnostic cerebral angiograms after mechanical thrombectomy had increased procedure times, but this was not statistically significant (p = 0.10). Conclusion Multivessel diagnostic cerebral angiogram is a powerful tool for evaluation and visualization of the intracranial vessels. However, in patients that have undergone uncomplicated mechanical thrombectomy and have pre‐procedure CTA of the head and neck, it appears to substantially increase total cost while rarely finding previously unknown significant vascular pathology in non‐target vessels.