Marie Curie Action

A cartographic map to guide hepatectomies

Liver resection is the second clinical application targeted by the ARISE*ER consortium. The research team has directed its effort in providing an intraoperative navigation solution during liver resection. The main bottleneck in this problem is the image to patient registration, due to the deformation and topological changes done to the liver.

Our contribution is a new concept of an intra-operative 3D visualization system to support hepatectomies: the "Resection Map". This is a pragmatic solution to enhance liver resection accuracy and safety with an intuitive visualization of its critical inner structures. This system aims at improving the transfer of pre-operative liver planning information into the intra-operative surgical stage, both in laparoscopic and open approaches.

The concept

The "Resection Map" is a 3D representation of the planned resection path through the liver showing the relevant structures and risk areas. It is a smart visualization of the planning information built from CT image studies (see Figure 1).

Figure 1

The design of the 3D visualization (see Figure 2) combines a surgical view (on the left) and a progress view (on the right) to show the relevant structures around a certain point of the resection process. These relevant structures are selected by the position and width of the "resection window", what are interactivelly changed (download the video from Figure 2).

Video of Resection Map

Figure 2: Movie showing Resection Map use

This solution can be seen as an accurate cartographic map that the surgeon reads and mentally maps to the surgical scene. The resection progress is inferred from the sequential identification of the key landmarks displayed in the Map, as what a pirate would do to find his buried treasure. There is then a "mental registration" process relying on the skill of the physician. This solves the difficult problem of image to physical registration.

Seamless integration in the Operating Room

The conception of the Resection Map does not require any tracking or positioning system, and its integration in the OR is straightforward. A brief description of the additional steps in the workflow is: first, a preoperative definition of the resection plane; second, the translation of the resection line over the liver surface; and third, the interactive visualization of the Resection Map.

Figure 3 shows Dr F. Lamata guiding an hepatectomy (segments VI and part of VII) with the help of the Resection Map at the Hospital Clinico of Zaragoza (Spain). The Resection Map is read and mapped to the patient's anatomy, and helps to anticipate and locate the presence of the main veins. This means an additional confidence for the surgeon to respect the safety margin around the tumour.

Figure 3

Publications and Presentations