Vasodilation Needle for Trans-Radial Access

SUMMARY The number of percutaneous arterial access procedures using the transradial access (TRA) approach is growing rapidly in the US. Interventionalists are adopting the TRA technique due to lower risks associated with bleeding and no need for active vascular closure devices. TRA catheterization also satisfies patients because of increased comfort and mobility. Same-day discharge is generally possible, which lowers costs for patients and health insurance companies. Radial artery spasm (RAS) is the most common complication encountered with the TRA technique, however, making access difficult and/or causing sheath entrapment. RAS can be painful for patients and is difficult for interventionalists to manage. Various pharmacological agents are used, but there are two problems with that strategy. First, there is no generally accepted drug regimen with proven efficacy in treating RAS. Second, pharmacological treatment is initiated only after a problem has arisen. Since the clinically important problem of RAS persists, we propose a completely different approach to mitigating this complication; i.e., electrical-induced relaxation of radial artery smooth muscle cells by use of electrified needle (e-needle). Our preliminary data show that the radial artery dilates in response to electrical stimulation with extracellular electrodes. This observation leads us to hypothesize that TRA devices can be transformed into vasodilating extracellular electrodes (with the return path provided by a skin patch electrode). Our aim is to assemble a prototype device and demonstrate its safety and efficacy in vivo in swine. The novel access e-needle will be used under ultrasound guidance to simultaneously measure radial artery diameter and assess prototype efficacy. Further, safety will be determined by measuring the electrocardiogram and arterial blood pressure during prototype use as well as histopathology after explanting the swine radial artery. Our novel approach to RAS promises to shift the current clinical paradigm from one of ad hoc attempts at pharmacological management (in which there is no consistency, but undesired side effects like hypotension) to one based on well-understood biophysical and biomedical engineering principles. Our project offers to improve patient care and save time for physicians with a novel TRA e-needle that dilates the artery it contacts the vessel for access. This will spare patients the pain of experiencing vasospasm, eliminate risks from unnecessary pharmacological agents, lower medical costs, and improve physician efficiency.NARRATIVE Percutaneous arterial catheterization, used in a wide variety of procedures including angiography and stent placement, is traditionally done through the femoral artery, but physicians are increasingly opting to use an artery in the wrist. This is a development for patients, who can quickly recover and walk out of the hospital the same day; however, radial access spasm is a frequent complication that is painful for patients and challenging for doctors. Our project is aimed at using safe and effective electrical stimulation through the access needle to relax the radial artery to enhance patient comfort, improve physician efficiency, and reduce health care costs.