Experiments for the Development of a Steerable Microcatheter

Sumitomo Bakelite has developed a steerable microcatheter with a mechanism on the handle for changing the direction of the catheter tip. Experiments were conducted in an animal model to evaluate the practicality of the catheter with the goal of introduction into clinical use.

The steerable microcatheter has the following specifications: external diameter 2.4F/2.9F (distal/proximal portion); internal diameter 0.021 inches; effective length 125 cm; and it is fitted with a dial on the proximal portion for moving the tip. Five interventional radiologists evaluated the microcatheter in animal experiments using piglets. The test catheter was compared with commercial straight microcatheters based on procedure time required to insert the catheter into two prescribed patterns of arterial branching (P-1: hepatic artery, P-2: iliac artery), fluoroscopy time, amount of contrast agent used, and frequency of guidewire use. Furthermore, the renal arteries into which each catheter was inserted were excised and examined for the extent of vascular damage.

Compared to the commercial products, the steerable microcatheter used without a guidewire required shorter procedure time (43.0/75.2% reductions in P-1/P-2), fluoroscopy time tended to be shorter (5.1/74.1% reductions), and the amount of contrast agent used tended to be lower (38.2/52.3% reductions). No damage was seen to the luminal surface of the renal arteries traversed by either microcatheter. During the experiment, there were no problems or defects with either microcatheter while intravascular procedure.

These animal experiments confirmed that the steerable microcatheter had the functionality required for its development as a commercial medical device.