The transjugular intrahepatic portosystemic shunt (TIPS) procedure is one of the most technically challenging procedures in interventional radiology [1].
During the TIPS procedure,
a shunt is created in the liver to decrease the high blood pressure for patients with portal hypertension [2].
Especially the intrahepatic puncture is a challenging part of the procedure [3].
During this critical step,
the interventional radiologists (IRs) desire to gain access to the portal vein and intend to puncture from the hepatic vein,
through the liver,
into the portal vein.
After this step,
a shunt can be placed between the hepatic vein and portal vein to bypass blood from the liver into the systemic circulation.
Limited information is available from the image guidance systems to perform the intrahepatic puncture [4-5].
Before the procedure,
IRs first plan their actions on CT [6-7] and develop a mental representation (mental model) of the anatomy,
the puncture and other aspects [8].
During the intraoperative part of the TIPS procedure,
mainly fluoroscopy is used to guide the IRs [9].
However,
three-dimensional,
real-time information about the anatomy and instruments is limited [4-5].
Therefore,
IRs often rely on their mental model and own skills to complete the procedure [8,10].
IRs mainly have to proceed through trial and error when performing the puncture [4],
multiple needle passes are frequently needed and these can cause complications [9].
The above shows the need for additional support from the image guidance system,
but also from a good planning aid.
A proper planning user interface (UI) might help IRs to provide the desired support.
Currently,
such a planning-UI is unavailable: IRs can now solely scroll through CT or other pre-operative images [6-7] and have to imagine and remember planned actions [6].
In our study,
we introduce a UI using three-dimensional ultrasound (3D US) information for planning the puncture.
3D US is a promising modality to provide appropriate guidance [11].
A US planning-UI might help,
by:
1. visualizing what can be expected and what options are feasible to puncture the portal vein.
With the planning-UI,
IRs can see and interact with the patient’s anatomy and possible puncture trajectories in 3D.
This could help IRs to get familiar with the anatomy,
anatomical constraints,
risks,
puncture possibilities and anatomical distances before the procedure.
Based on that information,
IRs are able to set concrete expectations and select a desired puncture trajectory.
2. generating optimal 2D US planes for the intrahepatic puncture.
With the planning-UI IRs can select 2D planes which will show all the information needed by the performing IR to gain access to the PV,
such as the anatomy,
the puncture line and target point.
The planes can be visualized during the intrahepatic puncture in real-time.
The aim of this study is to assess the usability of the UI which concerns the planning of an intrahepatic puncture.