Newly designed sheaths for gastroduodenal intervention: An experimental study in a phantom and dogs

Objective: To evaluate the usefulness of newly designed sheaths for gastroduodenal intervention in a gastric phantom and dogs. Materials and Methods: A regular sheath was made using a polytetrafluoroethylene tube (4 mm in diameter, 90 cm long) with a bent tip (4 cm long, 100 degree angle). For the supported type of sheath, a 5 Fr catheter was attached to a regular sheath to act as a side lumen. To evaluate their supportability, we measured the distance of movement of the sheath's tip within a silicone gastric phantom for three types of sheath, the regular type, supported type, and supported type with a supporting guide wire. The experiments were repeated 30 times, and the results were analyzed using ANOVA with the postHoc test. In addition, an animal experiment was performed in six mongrel dogs (total: 12 sessions) to evaluate the torque and supportability of the sheaths in the stomach, while pushing a guide wire or coil catheter under fluoroscopic guidance. Results: In the guide wire application, the distances of movement of the sheath tip in the three types of sheath, the regular type, supported type, and supported type with supporting guide wire, were 8.40 ± 0.51 cm, 6.23 ± 0.41 cm, and 4.47 ± 0.32 cm, respectively (p < 0.001). In the coil catheter application, the corresponding values were 7.22 ± 0.70 cm, 5.61 ± 0.31 cm and 3.91 ± 0.59 cm, respectively (p < 0.001). All three types of sheath rotated smoothly and enabled both the wires and catheters to be guided toward the pylorus of the dog in all cases. Conclusion: The newly designed sheaths can be useful for gastroduodenal intervention.