During the last decade progress in preoperative patient assessment, refinement of the indications for resection, improved surgical technique and the development of new surgical devices have greatly enhanced the safety of open hepatectomy.
On the contrary, laparoscopic liver surgery is a field in its infancy and scientific evidence of its benefits over those of traditional open technique has not been well shown.
Since the introduction of laparoscopic cholecystectomy in 1987, minimally invasive surgery has been progressively applied to various benign and malignant gastrointestinal conditions and to solid organs, such as the spleen, kidney, pancreas and adrenal gland. Nevertheless laparoscopic liver surgery has developed more slowly.
The reasons for slow progress are the associated technical difficulties and concern about the intraoperative hazards of bleeding and gas embolism. Laparoscopic liver surgery presents unique technical challenges and controlling haemorrhage from large intrahepatic vessels may be difficult. Cases of gas embolism have been reported, hence the risks of this potentially lethal complication add to the concerns associated with laparoscopic liver surgery.
An additional concern is the potential risk of tumour seeding and the impact that this may have on the long-term results of laparoscopic surgery in patients with malignant disease.
Laparoscopic liver surgery has been described for benign cystic liver diseases, such as biliary and congenital liver cysts, but it was not until 1992 that Gagner et al reported the first non-anatomical resection of a benign liver tumour (FNH). The first true anatomical liver resection, namely a left lateral segmentectomy, was subsequently reported in 1996 by Azagra et al Since then, only limited series have been published and Biertho and Gagner in a review of the literature reported only 186 laparoscopic liver resections performed between 1991 and 2001.
The advent of technological refinements in new laparoscopic instruments, experience in laparoscopic and hepatic surgery and application of the principles of oncologic surgery have led some groups, including ours, to expand the role of laparoscopic liver resections with the aim of decreased postoperative pain and shortened recovery time compared with open hepatectomy. Improved instrumentation has contributed to safer laparoscopic hepatectomy although none of these instruments are yet perfect. Intraoperative laparoscopic ultrasonography permits clear visualisation of the extent of tumours and their relationship to the hepatic vascular anatomy and permits identification of the plane of resection. The development of flexible ultrasound probes allows the tumour to be visualised as well as with open intraoperative ultrasonography. The introduction of the ultrasound scalpel has greatly improved the ability to maintain haemostasis during laparoscopic surgery; nevertheless haemostasis is still a major challenge in laparoscopic liver resection and there is an urgent need for technical improvement to the current generation of haemostatic devices. An argon beam coagulator has been developed recently and shown to reduce blood loss. It allows for rapid and diffuse superficial coagulation at the plane of transection with little carbonisation of liver tissue. However, care must be taken not to increase the intra-abdominal pressure by the flow of the argon beam as this may result in gas embolus. The use of linear staplers to transect the main hepatic veins makes the parenchymal resection safer and faster.
The efficacy of laparoscopic major hepatectomies remains questionable, although a limited number of hemihepatectomies have been performed. Intraoperative control of major intrahepatic vessels and application of total vascular isolation techniques are difficult to achieve laparoscopically. At present, major hepatic resections should be performed only by a handful of skilled surgeons who have developed expertise in the advanced laparoscopic approach and who have sufficient training in open liver surgery to allow rapid open conversion when necessary.
Hand-assisted laparoscopic surgery has been developed to facilitate major hepatic resection by hand-assisted procedures in order to improve liver exposure and vascular control and increase the safety of the procedure. The advantages of this over other approaches await prospective evaluation.
Increasingly data suggest that immune function is better preserved after laparoscopic than after open surgery. If true, this may confer a survival advantage to a person undergoing a laparoscopic procedure over the open approach provided that the primary tumour has been fully resected. The early postoperative period may be a critical time during which the fate of many cancer patients is determined. If this is the case then the early postoperative period may be the ideal time for appropriate adjuvant therapies to enhance the immunological response against tumours.
Minimally invasive surgery is here to stay but is still a developing field in which careful patient selection is essential. Currently the tumour's location within the liver and its size limit selection of candidates for laparoscopic resection. At present only limited liver resection for lesions of 5 cm or less in diameter located in the left or peripheral right segments (segments II–VI of Coinaud's classification) or formal left lateral segmentectomies can be safely performed through a laparoscopic approach. Major hepatic resections need careful evaluation at centres specialising in this field.
In this special issue of HPB focusing on laparoscopic liver resection, the challenges of this rapidly developing field are addressed. Each of the contributors has discussed specific aspects of their specialised area, exposing its limits but also its advantages. They have discussed their technique and where possible the results.
The authors of this issue have demonstrated that minimally invasive liver surgery is feasible, safe and reproducible. It has been performed only in highly specialised centres by surgeons using new technologies. In addition the surgeons are expert in both liver and advanced laparoscopic surgery.
I am very pleased and sincerely grateful to all of the authors for their outstanding effort in contributing to this issue.