E-105 Learning curve for diagnostic cerebral angiography: transradial access versus transfemoral access

Background Diagnostic cerebral angiography (DSA) and neurointerventions have traditionally been performed via transfemoral access (TFA). The perception of a steep learning curve associated with transradial access (TRA) has limited adoption in neurointervention. This study compares the learning curves of transradial vs. transfemoral DSA in a cohort of neurointerventional fellows. Methods The first 150 consecutive radial and femoral DSA were identified for each fellow from a prospective neurointerventional registry from July 2017 to March 2020. Total fluoroscopy time and number of intracranial arteries injected were recorded. Mean fluoroscopy time per intracranial artery injected (termed angiographic efficiency) was calculated and was used as a surrogate measure of technical proficiency. Mean angiographic efficiencies were compared across partitions of 25 consecutive DSAs (e.g. 1–25, 26–50, 51–75, etc.). Results There were 607 radial DSA and 635 femoral DSA identified among 5 fellows. The overall angiographic efficiencies were not significantly different based on access site (radial mean 3.2 min, femoral mean 3.7 min, p>0.05). For 3 fellows without prior endovascular experience, technical proficiency was obtained between 25–50 femoral DSA procedures. Among these same fellows, one fellow achieved technical proficiency after 25–50 radial DSA procedures, while the other 2 fellows had flattened learning curves. There were 2 fellows that had no significant learning curve for either access type, but both had extensive experience with endovascular procedures prior to starting fellowship. Two patients (2/1342 = 0.1%) experienced transient neurologic symptoms post-procedure. Among 635 femoral DSA, there were 22 (3.5%) minor adverse events (14 small groin hematomas not requiring transfusion, 1 pseudoaneurysm, 7 non-flow-limiting dissections). Among 607 radial DSA, there were 3 (0.5%) minor adverse events (2 small forearm hematomas, 1 intraluminal wire removed with radial cut-down), which was significantly less than femoral DSA minor adverse events (p=0.0001). Radial to femoral conversion rate was 1.2% (7/607, 2 radial spasm, 2 unsuccessful radial artery access, 3 aberrant right subclavian artery). Femoral to radial conversion rate was 0.3% (2/635). From March 2019 to February 2020, the proportion of DSA performed via transradial access increased from 36% to 78% at our institution. Conclusion This study demonstrates the learning curves for both TRA and TFA diagnostic cerebral angiograms. Proficiency improves significantly with either type of access, typically requiring between 25–50 procedures. TRA DSA have significantly less access site complications than TFA DSA. Disclosures M. Tso: None. G. Rajah: None. R. Dossani: None. M. Meyer: None. M. McPheeters: None. K. Vakharia: None. M. Waqas: None. K. Snyder: None. E. Levy: None. A. Siddiqui: None. J. Davies: None.