2016 年 10 巻 5 号 p. 236-242
Objectives: Manual shaping of a straight microcatheter is required when guiding or retention of a microcatheter with a pre-shaped tip is difficult. According to the manufacturer’s instructions, it is recommended that the microcatheter be shaped by steaming “for 30s” and “25 mm away from the steam source”. However, insufficient shaping and blunting can occasionally occur during the procedure. In this technical note, we present the optimal conditions of shaping for a microcatheter system.
Methods: In this study, we used a hot air gun (BOSCH, Gerlingen, Germany) as the shaping source and a Headway microcatheter (Microvention, CA, USA; Terumo, Tokyo, Japan). After measuring the difference between the preset and the actual temperature value, shaping was performed at different temperatures (preset temperature of 110°C–140°C) and time intervals (30s–120s).
Results: The actual temperature was constant at 20°C below the preset temperature, at a distance of 2.5 cm from the hot air outlet. We performed shaping at a preset temperature of 110°C–140°C (i.e., 90°C–120°C actual temperature) for 30s–120s. Because the Headway microcatheter could not tolerate preset temperature higher than 130°C (i.e., actual temperature of 110°C), the distal tip fluffed, bubbled, and perforated. We examined the durability under each condition, comparing the shape just after mandrel removal, after micro-guidewire manipulation, and after stretching in a vascular model. The highest moldability and durability were achieved at a time interval of 90s–120s, and a preset temperature of 120°C (i.e., 100°C actual temperature).
Conclusion: The Headway microcatheter showed the best performance at a heating time of 90s and a preset temperature of 120°C (i.e., 100°C actual temperature) in hot air gun shaping, although the optimal temperature and time interval may vary with the used microcatheter, depending on each instrument structure and materials.