Development of Navigation Systems for Image-Guided Laparoscopic Tumor Resections in Liver Surgery

Abstract

Minimally invasive surgery has become a viable alternative to conventional surgery. The technical advantages of minimally invasive surgery can be translated into clinical benefits for the patients, i.e., less postoperative pain and impairment of lung function, better cosmetic results, shorter hospitalization, and earlier convalescence. Laparoscopic operations have replaced a significant proportion of open surgical procedures and are now routinely used. While the role of laparoscopic surgery has been generally accepted for the management of benign disorders, there is an ongoing debate regarding the adequacy of this technique in surgical oncology. There is evidence that minimally invasive surgery can reduce perioperative morbidity in cancer patients. However, definite validation of these procedures for tumor surgery is not yet available due to the lack of prospective randomized trials providing reliable long-term data on disease-free survival and overall survival. It seems likely that minimally invasive procedures will play an important role for the treatment of preneoplastic lesions and tumors of limited size. There are some technical limitations to laparoscopic surgery. The degrees of freedom for the instruments are limited because of the minimal access via the trocars. The absence of direct organ palpation and the lack of the third dimension are still limits of laparoscopy. The surgeon’s orientation and the location of anatomical and pathological structures is therefore more difficult than in open surgery. Modern image-guided surgery (IGS) systems have the potential to compensate these limitations. Preoperative computer-based intervention planning and intraoperative navigation systems are today routinely used for certain indications in neurosurgery, ENT and orthopedic surgery. Nevertheless major research efforts are still necessary to examine the clinical impact of image-guided surgery on current indications, to adapt the systems to other indications and to solve some open problems like intraoperative deformations. In liver surgery, computer-assisted 3D modeling and planning based on preoperative CT or MRI data allows much more accurate planning of surgery and may help to select the optimal procedure [1]. Surgeons can obtain a better steric vision of the individual anatomy, the location of the tumor in relation to the vascular structures and the individual vascular territories defining the resection planes. The use of such planning systems in oncological surgery and liver transplantation is in routine use at some clinics and the number of users is increasing. But at the end of this preparatory process, surgeons have to carry out the surgical plan on the patient in the OR. Intraoperative navigation systems support the surgeon to transfer preoperative plans precisely and safely. In neurosurgery, ENT surgery, orthopedic and trauma surgery navigation systems are well established for certain indications and several commercial systems are available. The main problem in liver surgery or in general in visceral surgery is the deforma2 Development of Navigation Systems for Image-Guided Laparoscopic Tumor Resections in Liver Surgery