Performance characteristics of microcatheter systems in a standardized tortuous pathway

• Published in: American journal of neuroradiology : AJNR Vol. 19; no. 8; pp. 1571 - 1576
• Main Authors: Zoarski, GH, Mathis, JM, Hebel, JR
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01.09.1998; American Society of Neuroradiology
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Angioplasty, Balloon - instrumentation; Biological and medical sciences; Brain - blood supply; Carotid Artery, Internal; Carotid Stenosis - therapy; Emergency and intensive care: techniques, logistics; Equipment Design; Humans; Intensive care medicine; Medical sciences; Models, Cardiovascular; Perfusions. Catheterizations. Hyperbaric oxygenotherapy; Polytetrafluoroethylene; Performance evaluation; Medical equipment; Intracranial; Microcatheterism; Load; Guide; Force; Catheter; Wire; Coatings; Biomechanics; Reproducibility; Blood vessel; Carotid; Circulatory system; Hydrophilic compound; Simulation model; Comparative study
• ISSN: 0195-6108; 1936-959X

Published reports of controlled experiments designed to evaluate the performance of over-the-wire microcatheter systems are rare and have often been based on subjective impressions from small clinical series. This investigation was designed to compare the load forces required to propel state-of-the-art, hydrophilically coated microcatheters from each of four manufacturers through a standardized tortuous pathway constructed of polytetrafluoroethylene tubing. Currently available hydrophilically coated microcatheters were provided by four manufacturers. A 20-cm long, three-dimensional pathway simulating the intracranial carotid circulation was constructed of 0.065-in. (inner diameter) polytetrafluoroethylene tubing and immersed in a water bath at 37 degrees C. Testing was performed using an Instron tabletop load frame fitted with a 2-lb load cell. Durability and load force tests were conducted using a 0.014-in. stainless steel noncoated guidewire, with the wire tip protruding 1 cm beyond the catheter tip. At least four samples of microcatheters from each manufacturer were tested. Extensive trackability testing of the guidewire alone established reproducible performance with maximum load forces of less than 8 g. Maximum gram forces for the four reinforced microcatheters were not greatly different, measuring between 9 and 14 g. Excessive buckling of the only nonreinforced catheter was initially overcome early in the pathway in a staccato, stepwise fashion. After reaching a critical load, however, the catheter and guidewire prolapsed. All reinforced microcatheters tested established good and reproducible performance in our model. Reinforced microcatheters provided superior trackability over the one nonreinforced device tested.