Navigation systems in liver surgery: the new challenge for surgical research.

Abstract The authors describe the theoretical basis and development of simulation systems that led to the birth of "navigation in liver surgery." Navigation is a new technological application in the surgical field that has already been successfully used in neurosurgery and orthopedic surgery. A precondition to navigate a liver resection is the availability of a map. There are three main methods to acquire images and build a three-dimensional map. Efforts to make navigation "feasible" have been made, but some limits are still affecting the method. Lack of millimetric accuracy, deformation of the liver parenchyma during resection, and breathing movements are some of the most important criticisms of this method, which, however, is still in its infancy. Not only experimental applications but also current and future foreseeable applications of such a technology are overviewed. Goals of this technology should be to reduce the intraoperative stress on surgeons, to shorten resection time, and even indirectly to enlarge resectability of patients. Further developments of this new technology applied to liver surgery could lead in the near future to safer and more precise resections, reducing the risk of postoperative liver failure, even in the presence of large anatomical alterations or, even more frequently in this surgical field, anatomical variants.