Forming the Simmons Catheter for Cerebral Angiography and Neurointerventions via the Transradial Approach—Techniques and Operative Videos

Objective: Transradial access has been used increasingly for diagnostic cerebral angiography and neurointerventions. This requires development of a new skillset. Forming the Simmons catheter to catheterize the cerebral vessels is the most fundamental. Patient anatomy can complicate the formation of the Simmons catheter and the success of the procedure. The aim of this paper is to identify and describe the techniques that can be used transradially to facilitate the formation of the Simmons catheter for catheterization of the cerebral vessels. Methods: We reviewed our series of 85 cerebral angiograms performed via a transradial approach at our institution between 2018 and 2019. We identified the techniques employed to form the Simmons catheter and compiled operative videos demonstrating each technique and its nuances. Results: We have identified 7 techniques used to form the Simmons catheter from a right radial approach: in the ascending aorta, in the descending aorta, in the aortic arch, by deflecting the catheter off of the aortic valve with the glidewire in the common carotid artery, by deflecting the catheter off of the aortic valve with the glidewire in the descending aorta, and directly in the right or left common carotid arteries. We have identified that formation of the Simmons catheter from a left radial approach is most easily done in the descending aorta. Conclusions: Transradial artery access has become increasingly common in cerebral angiography and neurointerventions. We describe techniques used for the formation of the Simmons catheter, a fundamental skill necessary for transradial cerebral angiogram or neurointervention.