Electromagnetically navigated TIPS procedure: phantom and in vivo evaluation.

Purpose: To evaluate the feasibility of electromagnetic tracking (EMT) transjugular intrahepatic portosystemic shunt (TIPS) placement in a phantom and in vivo setting. Materials and Methods: A custom designed TIPS set consisting of a stainless steel stylet, a polypropylene catheter and a stainless steel outer canula was developed. In the tip of both stylet and outer canula coils were integrated to allow tip detection through an electromagnetic tracking system (Aurora, Northern Digital, Waterloo, Canada). For navigation of the TIPS set a software prototype was developed that allows visualization of both the stylet and the outer canula tip position in a previously acquired C-arm CT dataset. The EMT-TIPS procedure was performed in a custom made gel-wax phantom (n=80 trials) and in 8 domestic pigs. Domestic pigs were chosen as an animal model for challenging TIPS procedures. Time/number of punctures aiming at the portal vein were recorded. Results: In the phantom setting intervention time to cannulate the portal vein (PV) was 144.0 ± 62.8 s A mean of 1.2 ± 0.4 punctures were needed for PV cannulation.In the in vivo trials the TIPS procedure was successfully performed in 5 out of 8 animals. Time for the complete TIPS procedure including prosthesis placement ranged from 40 to 562 minutes with a notable learning curve between the trials. Conclusion: EMT-guidance of TIPS placement proved to be feasible in vitro as well as in vivo. The system holds promise to substantially facilitate challenging TIPS procedures. [Copyright &y& Elsevier]