Utilizing 3D printing to assist pre-procedure planning of transjugular intrahepatic portosystemic shunt (TIPS) procedures: a pilot study

Abstract

Background: 3D (three-dimensional) printing has been adopted by the medical community in several ways, procedure planning being one example. This application of technology has been adopted by several subspecialties including interventional radiology, however the planning of transjugular intrahepatic portosystemic shunt (TIPS) placement has not yet been described. The impact of a 3D printed model on procedural measures such as procedure time, radiation exposure, intravascular contrast dosage, fluoroscopy time, and provider confidence has also not been reported.

Methods: This pilot study utilized a quasi-experimental design including patients who underwent TIPS. For the control group, retrospective data was collected on patients who received a TIPS prior to Oct 1, 2020. For the experimental group, patient-specific 3D printed models were integrated in the care of patients that received TIPS between Oct 1, 2020 and April 15, 2021. Data was collected on patient demographics and procedural measures. The interventionalists were surveyed on their confidence level and model usage following each procedure in the experimental group.

Results: 3D printed models were created for six TIPS. Procedure time (p = 0.93), fluoroscopy time (p = 0.26), and intravascular contrast dosage (p = 0.75) did not have significant difference between groups. Mean radiation exposure was 808.8 mGy in the group with a model compared to 1731.7 mGy without, however this was also not statistically significant (p = 0.09). Out of 11 survey responses from interventionists, 10 reported "increased" or "significantly increased" confidence after reviewing the 3D printed model and all responded that the models were a valuable tool for trainees.

Conclusions: 3D printed models of patient anatomy can consistently be made using consumer-level, desktop 3D printing technology. This study was not adequately powered to measure the impact that including 3D printed models in the planning of TIPS procedures may have on procedural measures. The majority of interventionists reported that patient-specific models were valuable tools for teaching trainees and that confidence levels increased as a result of model inclusion in procedure planning.

Keywords: 3D printing; Anatomic segmentation; Pilot study.; Procedure planning; TIPS.

Fig. 1

Segmentation Process A screen capture of the segmentation software 3D Slicer shows a model being created from a CT scan. On the top left, bottom right, and bottom left, different views of the patient’s imaging are displayed with bright colors overlaying the anatomy that has been selected from the background CT (red = portal venous, blue = hepatic/systemic venous). On the top right the resulting 3D geometry is displayed

Fig. 2

3D Model for TIPS planning (A) 3D rendering of a model displayed in Meshmixer. This is the final geometry sent to the printer but does not yet include the support structures required for a successful print. (B) The finished 3D model in the hands of an interventionist, now ready to be used in the procedure planning process

Fig. 3

Post-Procedure Survey Interventionists were sent this short survey following each case that included a model in the planning process

Fig. 4

Procedural Measures

Fig. 5

Variable Opacification of the Hepatic Vessels (A) Contrast enhanced CT in the portal venous phase displayed in the axial plane shows opacification of the hepatic vessels (arrows) making segmentation challenging but possible. (B) Contrast enhanced CT in the venous phase displayed in the axial plane demonstrates very poor opacification of the hepatic vessels (arrow) making segmentation and model creation impossible