E-017 Topical nitropaste in transradial cerebral angiography: effects on radial artery caliber and radiographic vasospasm

Introduction Transradial access for cerebral angiography is gaining popularity and has been associated with fewer serious access site complications and shorter recovery time than transfemoral access. However, the smaller size of the radial artery as compared to the femoral artery presents its own unique challenges. Topical nitropaste applied to the wrist and forearm prior to radial artery access has been shown to increase the radial artery caliber in cardiac procedures. We have incorporated this into our cerebral angiography practice and therefore sought to evaluate its use on radial artery caliber and post-procedure vasospasm. Materials and Methods We retrospectively reviewed cases of attempted transradial cerebral angiography from May 2020 to March 2022. In each case, topical nitropaste was applied to the right wrist and forearm prior to prepping and draping of the patient. Upon arterial access, intraarterial nitroglycerin (200mcg), verapamil (5mg), and heparin (weight-based dosing) are administered. During a five-month period, we measured radial artery cross-sectional diameters using ultrasound both before nitropaste application as well as afterwards at the time of arterial access. Pre- and post-nitropaste measurements were compared using Welch’s t-test. We also routinely perform radial artery angiography after sheath placement and again prior to sheath removal. The presence and severity of radial artery vasospasm was characterized as follows: none, mild (<50% reduction in diameter), moderate (50–70%), and severe (>70%). Results One hundred seventy attempted transradial diagnostic angiograms were identified. Pre- and post-nitropaste ultrasonography was performed in 47 cases. The mean vertical and horizontal cross-sectional diameters of the radial artery were 0.19cm and 0.23cm, respectively. These increased to 0.22cm and 0.26cm, respectively, after the topical application of nitropaste (p<0.001 and p<0.01, respectively). The mean cross-sectional area of the radial artery increased from 0.14cm2 before nitropaste application to 0.18cm2 after nitropaste (p<0.01). Overall, 10 cases (5.9%) were converted to transfemoral - eight (4.7%) because the microwire could not be advanced in the radial artery and two (1.9%) because the diagnostic catheter could not be sufficiently advanced due to presumed vasospasm. Final radial artery control angiograms were available for 143 cases (84.1%). Among these cases, 53.1% showed no radiographic vasospasm, 33.6% showed mild spasm, 13.3% showed moderate spasm. There were no cases of severe spasm. Conclusion The application of topical nitropaste to the wrist and forearm prior to radial artery access significantly increases the cross-sectional diameter of the radial artery. Its use in conjunction with intraarterial nitroglycerin, verapamil, and heparin upon arterial access is associated with minimal instances of clinically significant vasospasm. Disclosures E. Winterhalter: None. R. Abdalla: None. K. Nandoliya: None. J. Klein: None. R. Khazanchi: None. A. Alwakeal: None. S. Ansari: None. D. Cantrell: None. A. Shaibani: None. B. Jahromi: None. M. Potts: None.