Masaki Kawamoto

Laparoscopic hepatectomy: A systematic review, meta-analysis, and power analysis

PurposeA previous meta-analysis study demonstrated that bleeding and the duration of the hospital stay following laparoscopic hepatectomy (Lap) were significantly smaller and shorter, respectively, than for patients undergoing an open approach (Op). The aim of the present study was to re-evaluate perioperative variables and adverse outcomes in patients undergoing Lap versus (vs) Op after 2000.MethodsA PubMed and Ovid Medline search identified clinical studies that compared the outcomes of Lap vs Op patients after 2000. A meta-analysis and power analysis were performed.ResultsOperative time was not significantly different between the two approaches (95% confidence interval [CI]: −0.063 to 0.992). Patient bleeding in the Lap group was significantly lower than in the Op group (95% CI: −1.027 to −0.390). Complications with Lap patients were significantly less frequent (95% CI: 0.231–0.642), and the duration of the hospital stay for Lap patients was significantly shorter (95% CI: −0.950 to −0.530) than for Op patients. Only one paper presented 80% power with 0.05 α-errors in all four outcomes, whereas four studies did not have sufficient statistical power.ConclusionsThe clinical benefits of Lap include a smaller incidence of complications and a shorter duration of hospital stay at the current time. Several studies had too few cases to sufficiently evaluate these factors, although other studies were appropriately analyzed.

Serum Hyaluronate Level for Predicting Subclinical Liver Dysfunction after Hepatectomy

The serum hyaluronate (HA) level reflects sinusoidal endothelial cell function correlated with liver function. We have reviewed multiple liver function indicators from 37 patients who underwent hepatectomy for various liver diseases. The serum HA level was well correlated with the indocyanine green retention rate at 15 minutes (ICGR15), lectin-cholesterol (LCAT), hepatocyte growth factor (HGF), liver uptake ratio of technetium-99m galactosyl human serum albumin (99mTc-GSA) at 15 minutes (HH15), prealbumin, and hepatic uptake ratio of 99mTc-GSA at 15 minutes (LHL15). In addition, the model for end-stage liver disease (MELD) score at 7 days after operation was well correlated with serum HA, ICGR15, HH15, and LHL15. In patients who showed serum an HA level of = 100 ng/ml before hepatectomy, the MELD score had significantly deteriorated by 7 days after hepatectomy. Of the 20 patients who showed a serum HA level < 100 ng/ml before hepatectomy, 11 had high serum HA after hepatectomy. The bilirubin level 7 days after operation in this group was much higher than that for patients who maintained a serum HA level < 100 ng/ml after hepatectomy. In addition, the serum HGF level before hepatectomy in this group was significantly lower. We concluded that the serum HA level is a reliable indicator when evaluating liver function and predicting liver dysfunction after hepatectomy. Furthermore, patients with a significantly low HGF level who have a normal HA level are susceptible to liver dysfunction after hepatectomy.

Preoperative liver function assessments to estimate the prognosis and safety of liver resections.

Liver function assessment is important to ensure safe surgical procedures in patients with hepatocellular disease. Because the liver influences a wide variety of functions, including protein synthesis and metabolic, immune and storage functions, no single parameter is sufficient to adequately address all of these functions. We reviewed the relevant literature concerning the scoring systems, functional tests, plasma parameters and imaging modalities currently used to evaluate the liver function in an attempt to determine which parameters provide the most comprehensive and useful results. While the Child–Pugh scoring system is the gold standard for liver disease assessment, the liver damage grading system recommended by the Liver Cancer Study Group of Japan is also useful. Various models for end-stage liver disease scoring are used for organ allocation. While the indocyanine green clearance test is widely accepted throughout the world, other assessments have not been used routinely for clinical evaluations. The levels of plasma proteins, including albumin, prealbumin, retinol binding protein, apolipoprotein, coagulation factors and antithrombin III, represent the liver productivity. Liver fibrotic markers also correlate with liver function. Imaging modalities such as 99mTc-galactosyl serum albumin scintigraphy, 99mTc-mebrofenin hepatobiliary scintigraphy and transient elastography are also available, but future studies are needed to validate their clinical efficacy.

Propensity score analysis demonstrated the prognostic advantage of anatomical liver resection in hepatocellular carcinoma

AIM To compare the prognoses of hepatocellular carcinoma (HCC) patients that underwent anatomic liver resection (AR) or non-anatomic liver resection (NAR) using propensity score-matched populations. METHODS Between January 2002 and December 2010, 268 consecutive HCC patients, including 110 and 158 patients that underwent AR and NAR, respectively, were retrospectively enrolled in this study. Forty-four patients from each group were selected and matched using logistic multivariate analysis followed by propensity score analysis. RESULTS In the whole analysis set, the histological background of the liver, liver function, and tumor marker levels differed significantly among the groups. Although the overall survival (OS) and recurrence-free survival rates of the two groups did not differ significantly in the whole analysis set, the OS of the AR group was significantly longer than that of the NAR group after propensity matching (76.2 ± 6.3 mo vs 58.9 ± 6.3 mo; P = 0.0039). Although AR (HR = 0.456, P = 0.039) was found to be a prognostic factor in the univariate analysis, only vascular invasion (HR = 0.228, P = 0.002) and the hepatocyte growth factor level (HR = 52.366, P = 0.035) were subsequently found to be independent prognostic factors. CONCLUSION AR conveys a survival advantage over NAR in specific subpopulations of HCC patients with tumors of less than 5 cm in diameter, single tumor, and good liver function.

The Molecular Pathogenesis and Clinical Implications of Hepatocellular Carcinoma

The prognosis of hepatocellular carcinoma (HCC) is affected by tumoral factors and liver functions; therefore it is often difficult to select the appropriate therapeutic methods for HCC. Recently, two global phase III trials showed that sorafenib, which is a tyrosine kinase inhibitor, improved the prognosis of patients with advanced HCC. As a new therapeutic strategy for HCC, sorafenib is expected to expand the indication for HCC in the future. However, it alone is insufficient for the molecular-targeted treatment of HCC because the signaling pathway exists not only in cancer cells but also in normal cells. Recently, cancer stem cells (CSCs) have attracted attention as a novel therapeutic target for HCC. There is now much evidence that stem cell properties such as self-renewal, unlimited proliferation, and differentiation are highly relevant to cancer recurrence and the drug resistance of HCC. In this review, we describe the molecular pathogenesis and the current state and future development of molecular- and CSC-therapeutic targeted agents for HCC, citing various reports.

Highest intraoperative lactate level could predict postoperative infectious complications after hepatectomy, reflecting the Pringle maneuver especially in chronic liver disease.

The Pringle maneuver is used to minimize blood loss during liver transection; however, it may cause reperfusion injury, which can cause increased intraoperative lactate levels and an immune compromised state. This may further lead to infectious complications.

Hyperbaric oxygen stimulates cell proliferation and normalizes multidrug resistance protein-2 protein localization in primary rat hepatocytes

Hyperbaric oxygen therapy (HBO) has been used for many clinical treatments, including primary liver nonfunction. However, the cellular mechanism by which HBO treatment ameliorates liver function is not understood. Therefore, the purpose of this study was to elucidate this cellular mechanism using primary cultured rat hepatocytes in in vitro studies. Hepatocytes were treated with HBO at 1 day after plating, and the morphological and functional characteristics of bile canaliculi formed in cultured hepatocytes were observed by time‐lapse microscopy. Multidrug resistance protein‐2 localization was observed by confocal laser microscopy. In cultured hepatocytes, the labeling index in the HBO group at 2 days after treatment was significantly higher than that in the control group. In addition, the proliferating cellular nuclear antigen level in the HBO group was significantly higher than that in the control group. The contraction of the bile canaliculi in the HBO group was slower than in the control group and the dilatation of bile canaliculi in the HBO group was much larger than in the control group. Multidrug resistance protein‐2 in the HBO group was localized at the apical membrane. These results show that HBO stimulates hepatocytes to proliferate and HBO normalizes Multidrug resistance protein‐2 localization to the apical membrane, which could dilate bile canaliculi.

The impact of aging on morbidity and mortality after liver resection: a systematic review and meta-analysis

Abstract Surgery involving elderly patients is becoming increasingly common due to the rapid aging of societies all over the world. The objective of this study was to elucidate the prognostic differences between elderly and young patients who undergo liver resection. A systematic review based on the PRISMA flow diagram was conducted. Ovid Medline and PubMed were used to search for relevant literature published between January 2000 and March 2013, and the modified MINORS score was used to assess the methodological quality. In cases of hepatocellular carcinoma and miscellaneous liver tumors, the morbidity and mortality rate did not differ significantly between the elderly and young patients. For patients with colorectal metastatic liver cancer, the mortality of the young patients was 2.7 times lower than that of elderly patients. Our review of high-quality retrospective studies was able to elucidate the clinical risks of age on the outcomes after liver surgery in specific patient populations.

Prognostic impact of preoperative the branched-chain amino acid to the tyrosine ratio in hepatocellular carcinoma patients after initial hepatectomy.

IntroductionThe branched-chain amino acid/tyrosine ratio (BTR) reflects the amino acid balance and the severity of liver disease. The aim of the present study was to determine the relationship between BTR and liver function in patients with hepatocellular carcinoma (HCC). Furthermore, we evaluated the clinical usefulness of BTR as a prognostic indicator of disease-free and overall patient survival after initial hepatectomy.MethodsBetween January 2004 and December 2008, 105 consecutive HCC patients who underwent initial hepatectomy were enrolled in this study. The correlation between BTR and preoperative liver functional indicators was evaluated. The cutoff levels of BTR for 2-year survival prediction were evaluated using a dot blot diagram. The patients were divided into high BTR (4.5 or higher) and low BTR (4.4 or lower) groups and these were compared in terms of clinical variables such as liver functional indicators, operative variables, and tumor characteristics.ResultsThe preoperative BTR level decreased according to the severity of liver disease. BTR was correlated with the albumin, bilirubin, and prealbumin levels, as well as the prothrombin time. Although the preoperative liver function was significantly different between the high BTR and low BTR groups, the operative variables and tumor-related variables were not found to be significantly different. Postoperative complications in the high BTR group were significantly less frequent than in the low BTR group (p = 0.003). Disease-free and overall patient survival in the high BTR group were significantly longer than in the low BTR group (p < 0.001 and p = 0.021, respectively).ConclusionsBTR reflected the pathological liver background with a high correlation to the other liver functional indicators. BTR is thus considered to be a useful marker to predict postoperative complications, disease-free survival, and overall survival of HCC patients after initial hepatectomy. It is, therefore, a useful indicator of liver function and a predictor for the risk of cancer recurrence and overall survival in HCC patients.

Serum antithrombin III level is well correlated with multiple indicators for assessment of liver function and diagnostic accuracy for predicting postoperative liver failure in hepatocellular carcinoma patients.

BACKGROUND/AIMS Evaluation of preoperative hepatic reserve is critical to avoid a fatal clinical course such as liver failure. We retrospectively evaluated 158 consecutive hepatocellular carcinoma (HCC) patients who underwent initial hepatectomy. The aim of this study was to determine the correlations of multiple indicators for assessment of liver function before hepatectomy. Furthermore, diagnostic probability for the pathological background and prediction of postoperative liver failure/dysfunction was compared between the antithrombin (AT) III level and indocyanine green retention rate at 15 minutes (ICGR15). METHODOLOGY Between January 2001 and March 2008, 158 HCC patients who underwent initial hepatectomy were enrolled in this study. Spearmans correlation coefficients (r values) were obtained for 15 clinical laboratory tests including ATIII and ICGR15. Receiver operating characteristic (ROC) curve analysis was used for calculating the probability and predictive ability of the tests. RESULTS All 158 consecutive HCC patients were eligible for hepatectomy based on the Japanese guideline. ATIII is correlated with 13 of 14 other clinical tests, including albumin, bilirubin, prothrombin time, rapid turnover proteins, HGF, ICGR15 and others. The diagnostic probabilities to distinguish between normal liver and other pathological backgrounds of ATIII and ICGR15 were significantly different. The specificity of ATIII to predict postoperative liver failure/dysfunction was higher than that of ICGR15. CONCLUSIONS The serum ATIII level before hepatectomy is valuable to estimate the pathological background and predict postoperative liver failure/ dysfunction. It should be possible to use ATIII as an additional indicator for liver function and substitute for ICGR15 in the future.