Liver paper summary: IHPBA meeting 2004, Washington, DC.

The June, 2004 meeting of the IHPBA in Washington, D.C. provided an excellent opportunity for liver transplant and HPB surgeons and other liver-focused specialists to exchange important ideas regarding the current status and future directions in surgery. Presented papers could mostly be divided into one of 5 broad overlapping categories: liver transplantation, treatment strategies for hepatocellular carcinoma (HCC), management of non-HCC liver tumors, hepatic protection in liver surgery, and new technology in liver-related surgery. In addition, video sessions covering each of these areas facilitated the sharing of procedural approaches and were an important and popular feature of the meeting. Topics associated with liver transplantation were heavily focused on live donor liver transplantation, organ allocation, and recent developments impacting transplantation for HCC. There has been an overall decline in the use of live donor transplantation for adults in many regions of the world since 2002, but there appears to be renewed interest in this procedure. Donor-associated morbidity is receiving increasing scrutiny and changing algorithms for organ allocation (including the MELD system) are influencing consideration for live donor transplantation. The importance of waiting-times are being minimized with more attention on accurate disease-specific assessment to minimize recipient deaths while patients are waitlisted. The listing priority assigned to liver tumor patients remains an area of controversy in many regions of the world and increasing attention is being focused on the use of patient drop-out rates (by tumor stage) to assist in assigning priority. There is now a generalized recognition that transplantation of the highest acuity patients first leads to greater resource use and slightly worse results for the highest disease severity, but this appears to be the prevailing system in use in many regions of the world. There are continued investigations of liver support devices and auxiliary transplantation, but these have yet to advance to routine clinical care. An important observation during the meeting was the differing approaches regarding liver transplantation that appear to be undertaken in different regions of world based on cultural, access, and economic factors. For example, regions where there is no uniform standard for brain death declaration have either very low rates of transplantation, or have much greater use of live donor transplantation and/or use of non-heartbeating donors. Local and regional influence also seems to play a major role in decisions regarding management of HCC, particularly in Child's A and B cirrhotic patients. For example, patients in Asian countries appear to be much for likely to undergo resection for HCC, whereas transplantation appears to be more heavily favored in the U.S. and other Western countries. Data presented suggested that resection followed by salvage transplantation in those with recurrences in the remnant liver may be comparable to primary OLT, however this remains an area of controversy. Additional data (clinical trials) presented at future IHPBA meetings should clarify this issue and may allow modification of organ allocation for such patients. The role of adjuvant and neoadjuvant therapy for HCC remains unproven, with no evidence to support use of systemic therapy prior to, or following, liver resection or transplantation. Hepatic-directed therapy appears to be a useful adjunct for HCC, particularly transarterial chemoembolization (TACE) and ablative therapy, and recent preliminary studies suggest encouraging results with transarterial radiotherapy. The use of neoadjuvant therapy prior to transplantation is being increasingly utilized for prevention of tumor progression for listed patients, but there is no proven benefit to this approach and studies in this area are lacking. TACE and tumor ablation can lead to tumor down-staging for patients exceeding listing criteria (allowing for subsequent OLT), but outcomes for these patients appear to be worse than for patients with earlier stage disease. The treatment of colorectal metastases to the liver represents one of the better defined and more mature aspects of HPB surgery, where the role of surgery is now well-defined. Improvements in imaging technology, including the routine use of PET scanning for tumor staging at some centers, appears to facilitate improved patient selection and significantly improved long-term results. In addition, improvements in systemic and regional chemotherapy have allowed tumor down-staging which has resulted in conversion of unresectable to resectable hepatic tumors in up to 15% of patients in some reports. Several features of cholangiocarcinoma management emerged during the meeting including the improved tumor detection that has resulted from advances in non-invasive imaging; the need for invasive imaging studies including angiography has diminished markedly worldwide. Almost all centers now report that achieving margin-negative resection almost always requires concomitant major liver resection. There appears to be an increasing use of selective preoperative portal vein embolization for hepatic protection to lessen the risk of post-resection liver failure related to small liver remnant volumes. Additional studies are needed to clarify the role of adjuvant therapy for this malignancy. Developments in new technology were a major focus of the Washington IHPBA meeting. The increasing use of laparoscopy for standard liver resection, for live donor liver surgery, and to facilitate ablative therapy and hepatic artery infusion pump placement were all highlighted. Several groups reported on the use of the da Vinci robotic device to facilitate hepatic resection. Another area receiving much attention was the enhanced use of imaging in liver surgery, specifically for pre-operative virtual planning in liver resection (including teaching of surgical skills), and new imaging software available for 3-D imaging. While not yet available for routine clinical use, the development of instrument tracking and image-guidance during liver resection should occur over the next 5-years. New developments in transectional techniques have been recently introduced including the water-jet dissector, the use of radiofrequency resection, and saline-linked surface coagulators, among others. New approaches for use of microwave therapy for liver tumor ablation were presented, with suggestions that this technology may result in larger, more uniform ablation zones and shorter ablation times. The role of tumor ablation, however, remains unresolved and no prospective or case-controlled trials have been reported in patients with resectable tumors to establish the appropriate place for this therapy. A special session at the Washington meeting focused on outcomes in liver surgery including the need for evidence-based medicine in liver surgery. Significant variation in liver surgery exists worldwide depending on many factors including whether liver surgery is regionalized and local incentives for care. There appears to be great international interest in improving training in transplant and HPB surgery. Subspecialty training remains variable with experience often occurring as part of Surgical Oncology/HPB training, Liver Transplant/HPB training, or as part of GI/Laparoscopy/HPB training; it remains unclear whether sub-specialty training will become recognized at National Board levels. What does seem clear is that the casual or occasional performance of HPB surgery is no longer suitable and that experience in HPB/Transplant Surgery appears to correlate closely with improved patient outcomes. Finally, one of the most well received and popular features of the meeting involved the video sessions. A common feature of many presented videos included concomitant vascular reconstruction to extend or improve results of liver resection or transplantation. A significant percentage of videos also focused on developing laparoscopic and minimally invasive techniques for major liver cases. Based on the 2004 IHPBA meeting in Washington, DC, the IHPBA will continue to play a vital role in future liver surgery by providing an international forum for surgeons interested in HPB and liver transplant surgery. This forum with allow internationally prominent liver surgeons to present and discuss regional influences and differing approaches including such topics as organ allocation priorities, management strategies for HCC, novel use of imaging during liver surgery, the enhanced use of minimally invasive surgery, and the development of new technology in liver-related surgery. In this way the IHPBA should remain the leading international force in liver surgery for the foreseeable future.