Newly Designed Multifunctional Coil Catheter for Gastrointestinal Intervention: Feasibility Determined by Experimental Study in Dogs

Rationale and Objective: Conventional vascular catheters or sizing catheters are often inconvenient and time-consuming for gastrointestinal procedures. Our purpose was to evaluate the feasibility of a newly designed coil catheter by experimental study in dogs. Materials and Methods: Two catheter models were fabricated using a stainless-steel coil covered by heat shrinkable tube. The distal uncovered coil part was not elongated in model A but was elongated in model B. We developed 3 different types in each model: types II and III had 65-cm and 240-cm nitinol wires on the coil surfaces, respectively, but no wire was attached in type I. On the middle covered coil part, multiple holes were made into which to inject contrast medium, and multiple radiopaque markers were attached. In an experimental study using 4 mongrel dogs, we evaluated the ability of the coil catheter to pass over a guide wire to 30 cm distal from the pylorus, the ability of contrast to pass through the injection holes, the visibility of the radiopaque markers, and the ability of the coil catheter to be pushed without a guide wire to 120 cm distal from the pylorus. Results: All catheters were successfully passed to 30 cm distal from the pylorus. Contrast passage through the injection holes and visualization of the radiopaque markers were excellent. To advance to 120 cm distal from the pylorus, the average success rates of models A and B were 100% and 69%, respectively. In particular, model A type II showed the best results in average success rate and average number of trials to achieve success. Conclusion: This experimental study demonstrated the feasibility of the newly designed coil catheter for gastrointestinal intervention.