Background
In spite of all recent advances in liver surgery as the best treatment of tumors, the morbidity rate is still high. There is a great hope on image guided and navigated surgery in order to approach R0 resection and preserve higher liver remnant volume. The purpose of this review is to determine the current status of navigated systems in liver surgery.

Material and Methods
A Medline search was run between 1997 and 2013 using terms “Navigation system in liver surgery” and “computer assisted surgery (CAS)”.

Results
Navigation is led by the registration of preoperative and intra-operative data to optimize the accuracy of surgical procedure. The advent of multi-detector CT and high resonance MRI and 3D reconstruction have led to a better topologic understanding of tumor position. It has been introduced three different methods of navigation based on tracking systems. The most common type is Optical based navigated (OBN) system adjacent to the surgical field to present computer- generated 3D virtual liver resection proposals that can be transferred on the real liver. Acoustic based navigation (ABN) as well as Electromagnetic based navigation (EBN) are also introduced as new alternative or supplementary methods.

Conclusion
A critical limitation in navigated liver surgery is the fact that the position of the lesion can shift. Despite of a great deal of fundamental findings, we still need further developments and optimization of intra-operative navigation in liver surgery. The future improvements could be focused on continuous registration, tracking of movements and deformation.