Liver resection for colorectal metastasis is the only potentially curative therapy and has become the standard of care in appropriately staged patients, offering 5-year survival rates of approximately 35-40%. Also for symptomatic benign lesions and those of uncertain nature or large size, liver resection is a widely accepted treatment. Open hepatectomy (OH) is the current standard of care for the management of primary and secondary malignancies. Although the feasibility of laparoscopic hepatectomy (LH) has been established, only select centres have used this technique as their primary modality.

Laparoscopic liver resection was first reported in 1991. Over the last decade the method has gained wide acceptance for various liver resection procedures. Multiple retrospective case series and reviews comparing open with laparoscopic liver resection indicate that laparoscopic liver resection can be applied safely for both malignant and benign liver lesions. Laparoscopic liver resection has been associated with shorter hospital length of stay, reduced intraoperative blood loss, less postoperative pain, earlier recovery and better quality of life. Initially the left lateral segments of the liver were chosen for anatomic laparoscopic resection with good results. Many liver centres worldwide are currently adopting laparoscopic surgery for resection of anterior segments, but relatively low volumes to operate on, a significant learning curve and lack of evidence restrict the majority of liver surgeons to further adopt and disseminate this technique.

Recently, indications for resectability have been broadened by new (neo)adjuvant chemotherapies and (radio)embolisation techniques. A new impulse for the laparoscopic management of liver lesions came after the first reports of laparoscopic hemihepatectomies. Major hepatic resections can be technically demanding and hold an increased risk for morbidity. It was demonstrated that in expert hands major anatomical laparoscopic liver resections were feasible with good efficacy and safety. Expert liver centers are already performing laparoscopic (extended) hemihepatectomies. Currently, in European centers, a median hospital length of stay of 6.0 to 13.1 and 3.5 to 10.0 days is observed after respectively open and laparoscopic hepatic resection. In expert hands median duration of admission after major hepatic resection varies between 6 - 12.5 for open and 4 - 8.2 for laparoscopic surgery. However, reports are scarce and level 1 evidence on this matter is still to be presented.

Within the framework of optimising postoperative recovery, broader indications for resection and further adoption of laparoscopic liver surgery there is a need for a randomized trial.Regarding postoperative care, enthusiasm has arisen for the Enhanced Recovery After Surgery (ERAS®) program. This multimodal program, derived from Kehlet's 1990's pioneer work in the multimodal surgical care field, involves optimization of several aspects of the perioperative management of patients undergoing major abdominal surgery. In patients undergoing segmental colectomy, the ERAS® -program enabled earlier recovery and consequently shorter hospital length of stay. Furthermore, a reduction of postoperative morbidity in patients undergoing intestinal resection was reported. These results stimulated liver surgeons of the ERAS® group (Maastricht, Edinburgh and Tromsö) to adapt the ERAS®-program to patients undergoing open liver resection. Van Dam et al. found a significantly reduced hospital length of stay after open liver resection when patients were managed within a multimodal ERAS®-program. Besides a reduction of median total hospital length of stay from 8 to 6 days (25%), the data also suggested that a further reduction of stay could be possible as there was a delay between recovery and actual discharge of the patients. Moreover, Stoot et al. showed - retrospectively - a further reduction in length of stay from 7 days to 5 days when patients were operated laparoscopically and managed within an ERAS®-program. In this study there was also a delay between recovery and actual discharge of the patients. Earlier, Maessen et al. reported a median delay to discharge of 2 days after patients had functionally recovered from colonic surgery managed within an ERAS®-program. This delay is often linked to social problems, problems in homecare support or logistic problems.

The added value of the laparoscopic hemihepatectomy compared to the open hemihepatectomy has never been studied in a randomized controlled setting. Therefore, the multicenter international ORANGE II PLUS - trial has been constructed and will provide evidence on the merits of laparoscopic versus open hemihepatectomy.