Preoperative assessment of liver function

Correlation between morphological and functional liver volume in each sector using integrated SPECT/CT imaging by computed tomography and technetium-99m galactosyl serum albumin scintigraphy in patients with various diseases who had undergone hepatectomy

OBJECTIVES

The aim of the study was to accurately examine the functional volume (RI-vol) of the hepatic segments on single photon emission computed tomography/computed tomography (CT) fusion imaging by technetium-99m galactosyl human serum albumin scintigraphy and compare it with the RI-vol and morphological volume obtained on computed tomography (CT-vol).

METHODS

In 60 patients with various liver background statuses who had undergone hepatectomy, the RI-vol and CT-vol were examined in each sector using imaging analysis. The values from a control group (n=91) were used as reference data.

RESULTS

The mean RI-vol and CT-vol of the right liver were 64 ± 10 and 63 ± 6%, respectively, whereas the values for the left liver were 36 ± 10 and 37 ± 6%, respectively. Compared with the control group, the ratios in each hemiliver were similar. The mean RI-vol and CT-vol for each sector were also similar, and significant positive correlations were identified between the two volumes (P<0.01). In four patients with hepatic tumors involving the main hepatic vessels or the bile duct and in 10 patients who had undergone portal vein embolization, the actual RI-vol in the injured sector was significantly decreased compared with CT-vol (P<0.05). There were marked changes in functional volume in segment 6+7 and segment 2+3 after portal vein embolization (P<0.05).

CONCLUSION

Volumetric measurement using single photon emission computed tomography/CT imaging with technetium-99m galactosyl human serum albumin scintigraphy is useful for evaluating the functional volume in separated livers and offers a good reflection of the background liver status.

Kinetics of liver function tests after a hepatectomy for colorectal liver metastases predict post-operative liver failure as defined by the International Study Group for Liver Surgery

BACKGROUND

Post-hepatectomy liver failure (PHLF) has been defined by the International Study Group for Liver Surgery (ISGLS). The purpose of the present study was to examine the kinetics of conventional liver function tests (LFT) after a major liver resection and is the first to examine their utility in predicting PHLF in groups defined by the ISGLS.

METHODS

Consecutive patients undergoing a major liver resection for colorectal liver metastases were stratified into ISGLS groups and their LFT up to 1 year after surgery compared. Receiving-operating characteristic (ROC) analysis of LFT identified optimal thresholds in predicting category C liver failure.

RESULTS

In total, 32, 22 and 19 patients belonged to ISGLS groups A, B and C, respectively. The median international normalized ratio (INR) and bilirubin values on post-operative days 1, 3, 5 and 7 were significantly different among the groups (all P-values <0.05). ROC analysis of day 1 INR (AUC 0.813) and day 5 bilirubin (AUC 0.798) revealed thresholds of 1.35 and 52 μmol/l to have sensitivities of 85% and 81% and specificities of 63% and 73%, respectively, to predict group C liver failure.

DISCUSSION

Post-operative LFT after a major liver resection differs significantly among the three ISGLS groups. Thresholds of bilirubin and INR can be used to identify patients who are at a maximum risk of complications.

A rapid and accurate new bedside test to assess maximal liver function: a case report

Background

In liver surgery, appropriate preoperative evaluation and preparation of the patient is of cardinal importance. The up-to-date, preoperative prediction of residual liver function has thus far been limited. As post-hepatectomy liver failure is a major cause of mortality, a new and simple bedside test (LiMAx) has been developed to predict postoperative liver function in conjunction with preoperative volumetric analysis of the liver.

Case presentation

A 45-year-old patient presented with a cecal carcinoma and a large synchronous liver metastasis for major liver surgery. Liver function was determined by the LiMAx-test for the enzymatic capacity of cytochrome P450 1A2, which is ubiquitously and solely active in the liver. A solution of 2 mg/kg body weight ¹³C-labeled methacetin was injected as a bolus into an intravenous catheter and, thereafter, was metabolized into acetaminophen and ¹³CO2 and pulmonarily exhaled. The analysis of the ¹³CO2/¹²CO2 ratio was performed using online breath sampling over a period of maximally 60 minutes. Based on this test, a value of more than 315 μg/kg/h represents normal liver function. A laparoscopic right hemihepatectomy was planned during virtual resection with a residual liver volume of 48% and a preoperative anticipated residual LiMAx of 301 μg/kg/h. After successful resection, the initial postoperative LiMAx value was 316 μg/kg/h, indicating good liver function and a correct prediction of the outcome.

Conclusion

In the presented patient, residual liver function could be accurately predicted preoperatively using a combination of the new LiMax test with CT-volumetry. This test might significantly improve preoperative evaluation and postoperative outcomes in liver surgery.

Hepatectomy in a hepatocellular carcinoma case with Dubin-Johnson syndrome and indocyanine green excretory defect

A 77-year-old male patient with history of jaundice was referred to our hospital for treatment of hepatocellular carcinoma (HCC). He was found to have Dubin-Johnson syndrome (DJS), a clinical feature of constitutional jaundice with conjugated hyperbilirubinemia, and indocyanine green (ICG) excretory defect, both of which are rare conditions. Total bilirubin was 5.1 mg/dl and ICG retention at 15 min (ICGR15) (77.1 %). Converted ICGR15 from GSA scintigraphy was 15.9 %. Resection of the medial segment and ventral region of the anterior segment of the liver as well as cholecystectomy were performed. The background of the liver tissue was blackish yellow and consistent with DJS and chronic hepatitis. Although total bilirubin level increased to 8.2 mg/dl on the 2nd postoperative day, the patient ultimately recovered and he was discharged on the 14th day. His 1- and 2-year medical checkups indicated recurrence of HCC. He underwent transarterial chemoembolization and is presently doing well 39 months after surgery. We report here on evaluation and treatment of patients with such disorders.

Surgical outcomes after cardiac surgery in liver transplant recipients

OBJECTIVE

This was a single-center retrospective study to assess the surgical outcomes and predictors of mortality of liver transplant recipients undergoing cardiac surgery.

METHODS

From 2000 to 2010, 61 patients with a functioning liver allograft underwent cardiac surgery. The mean interval between liver transplantation and cardiac surgery was 5.4 ± 4.4 years. Of the 61 patients, 33 (54%) were in Child-Pugh class A and 28 in class B. The preoperative and postoperative data were reviewed.

RESULTS

The overall in-hospital mortality was 6.6%. The survival rate was 82.4% ± 5.1% at 1 year and 50.2% ± 8.2% at 5 years. Cox regression analysis identified preoperative encephalopathy (odds ratio, 5.2; 95% confidence interval, 1.8-15.5; P = .003) and pulmonary hypertension (odds ratio, 3.5; 95% confidence interval, 1.3-9.4; P = .045) as independent predictors of late mortality. The preoperative Model for End-Stage Liver Disease (MELD) scores of patients who died in-hospital or late postoperatively were significantly greater statistically than the scores of the others (in-hospital death, 23.7 ± 7.8 vs 13.1 ± 4.5, P < .001; late death, 15.2 ± 6.1 vs 12.3 ± 4.1, P = .038). The Youden index identified an optimal MELD score cutoff value of 13.5 (sensitivity, 56.0%; specificity, 67.6%). Kaplan-Meier survival analysis successfully demonstrated that the survival rate of the MELD score less than 13.5 (MELD <13.5) group was significantly greater than that of the MELD >13.5 group (MELD <13.5 group, 93.8% ± 4.2% at 1 year and 52.4% ± 11.8% at 5 years; MELD >13.5 group, 66.9% ± 9.6% at 1 year and 46.1% ± 11.1% at 5 years; P = .027). In contrast, the survival rate when stratified by Child-Pugh class (class A vs B) was not significantly different.

CONCLUSIONS

Cardiac surgery in the liver allograft recipients was associated with acceptable surgical outcomes. Preoperative encephalopathy and pulmonary hypertension were independent predictors of late mortality. The cutoff value of 13.5 in the MELD score might be useful for predicting surgical mortality in cardiac surgery.

Usefulness of Gd-EOB-DTPA-enhanced MR imaging in the evaluation of simple steatosis and nonalcoholic steatohepatitis

PURPOSE

To evaluate the usefulness of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging (EOB-MRI) in differentiating between simple steatosis and nonalcoholic steatohepatitis (NASH), as compared with MR in-phase/out-of-phase imaging. The correlations between the MR features and histological characteristics were preliminarily investigated.

MATERIALS AND METHODS

From April 2008 to October 2011, 25 patients (13 simple steatosis and 12 NASH) who underwent both EOB-MRI and in-phase/out-of-phase imaging were analyzed. The hepatobiliary-phase enhancement ratio and signal intensity loss on opposed-phase T1-weighted images (fat fraction) were compared between the simple steatosis and NASH groups. In the simple steatosis and NASH groups, the correlations between enhancement ratio and histological grade/stage were explored. In the NASH group, fat fraction was correlated with the steatosis score.

RESULTS

The enhancement ratio in NASH was significantly lower than that in simple steatosis (P = 0.03). In the simple steatosis and NASH groups, the enhancement ratio was significantly correlated with the fibrosis stage (r = -0.469, P = 0.018). Fat fraction in NASH was strongly correlated with the steatosis score (r = 0.728, P = 0.007).

CONCLUSION

In simple steatosis and NASH, the hepatobiliary-phase enhancement ratio of EOB-MRI showed significant association with fibrosis stage, and may be a useful discriminating parameter compared with the fat fraction measured by in-phase/out-of-phase imaging.

Area between the hepatic and heart curves of (99m)Tc-galactosyl-human serum albumin scintigraphy represents liver function and disease progression for preoperative evaluation in hepatocellular carcinoma patients

BACKGROUND/PURPOSE

We developed software to calculate the pixels of interest in the area between the hepatic and heart curves (ABC) of (99m)Tc-galactosyl human serum albumin (GSA) scintigraphy. The aim of this study was to examine the accuracy of the ABC to evaluate liver function before hepatectomy.

METHODS

Between January 2005 and December 2010, 205 consecutive patients who underwent initial hepatectomy were enrolled in this study. The ABC was calculated using original computer software. The area under the receiver operating characteristic curve (AUC) was calculated for evaluation of Child-Pugh score grade B (Child B), pathological chronic hepatitis (CH), and liver cirrhosis (LC).

RESULTS

The AUC of any indicator for Child B was more than 0.900 except bilirubin. The AUC of ABC for CH and LC (AUC 0.734 each) was comparable to those of HH15 (clearance index; AUC 0.704 and 0.700, respectively) and LHL15 (receptor index; AUC 0.703 and 0.706, respectively) in multiple receiver operating characteristic comparison.

CONCLUSIONS

We have developed a novel liver function indicator, the ABC, to count radioactivity in sequence. The ABC reflects liver function according to pathological deterioration of the liver. Although the ABC gave no significant advantage compared to HH15 and LHL15, it improved the AUC evaluation by 0.028-0.034.

Surgical risk in patients with cirrhosis

Surgery in the patient with cirrhosis is problematic, as encephalopathy, ascites, sepsis and bleeding are common in the postoperative period. Accurate preoperative assessment and planning, and careful postoperative management have the potential to reduce the frequency and severity of such complications, and reduce the length of hospital stay, but there is little literature evidence to prove this. Operative mortality and other risks correlate with the severity of the liver disease, co-morbidities and the type of surgery. The Child-Turcott-Pugh (CTP) score or model for end-stage liver disease (MELD) score may be used to determine the severity of the liver disease, but must also take into account recent changes in the patient's condition. Surgery that does not involve opening the peritoneum may have slightly better outcomes, as the risk of ascitic leak, sepsis and difficult fluid management are reduced. Mortality rates range from 10% in CTP-A patients to 82% in CTP-C patients. The presence of portal hypertension is an important negative predictor, especially in abdominal surgery, as refractory ascites may occur. Careful monitoring in the postoperative period and early intervention of complications are essential. Hepatic resections in cirrhosis are associated with other considerations such as leaving sufficient liver tissue to prevent liver failure, and are beyond the scope of this review.

Blockade of the renin-angiotensin system improves the early stages of liver regeneration and liver function

BACKGROUND

Partial hepatectomy is the preferred option for selected patients with colorectal cancer liver metastases (CRCLM). Sufficient liver regeneration (LR) is essential for a successful outcome in these patients. The blockade of the renin-angiotensin system (RAS) reduces the growth of several tumor types. The RAS also acts as a regulator of liver fibrosis and potentially LR. The angiotensin-converting enzyme (ACE) inhibitor, captopril, significantly inhibits the growth of CRCLM, but its effect on LR remains undefined.

METHODS

After 70% of partial hepatectomy, mice were randomly assigned to control or captopril-treated groups. LR was measured by liver-to-body weight ratio on days 1, 2, 4, 6, and 8. Hepatocyte proliferation, apoptosis and cell size, hepatic stellate cell (HSC) count, and sinusoidal endothelial cell density were quantified. Matrix metalloproteinase 9 (MMP-9) protein levels, liver injury markers, and RAS messenger RNA levels were also determined.

RESULTS

At day 2, captopril increased liver-to-body weight ratio (56.5 ± 1.7 captopril versus 49.3 ± 2.4 control, P = 0.027). This was associated with increased HSC count (65.4 ± 4.8 cells per 100,000 μm(2), 48.7 ± 2.3, P = 0.007) and MMP-9 levels (0.68 ± 0.12 AU, 0.12 ± 0.04, P = 0.014). The messenger RNA levels of angiotensin-converting enzyme (P = 0.045) and angiotensin 1 receptor (P = 0.039) were reduced by captopril at day 2.

CONCLUSION

Captopril enhanced early LR. This effect was associated with increased HSC numbers and MMP-9 protein, whereas hepatocyte proliferation was lower than controls. Captopril may provide a beneficial treatment option for the management of patients with CRCLM.

Liver function testing with nuclear medicine techniques is coming of age

Liver function is a broad term, as the organ participates in a multitude of different physiological and biochemical processes, including metabolic, synthetic, and detoxifying functions. However, it is the function of the hepatocyte that is central to sustaining normal life and dealing with disease states. When the liver begins to fail in severely ill patients, it forecasts a terminal outcome. However, unlike the glomerular filtration rate which clearly quantifies the key renal function, at most practice sites, there is no clinically available quantitative test for liver function. Although it is commonplace to assess indirect evidence of that function (by measuring blood levels of its end products and by-products) and to detect an acute injury (by following rising transaminases), a widely available test that would directly measure hepatocellular function is lacking. This article reviews current knowledge on liver function studies and focuses on those nuclear medicine tests available to study the whole liver and regional liver function. The clinical application driving these tests, prediction of remnant liver function after partial hepatectomy for primary liver malignancy or metastatic disease, is addressed here in detail. The test was recently validated for this specific application and was shown to be better than the current standard of practice (computed tomography volumetry), particularly in patients with hepatic comorbidities like cirrhosis, steatosis, or cholestasis. Furthermore, early assessment of regional liver function increase after preoperative portal vein embolization becomes possible with this technology. The limiting factor to a wider acceptance of this test is based on the lack of clinical software that would allow calculation of liver function parameters. This article provides information that enables a clinical nuclear medicine facility to provide this test using readily available equipment. Furthermore, it addresses emerging clinical applications that are under investigation.

Urinary trypsin inhibitor attenuates liver enzyme elevation after liver resection

BACKGROUND

Urinary trypsin inhibitors (UTI) have been widely used for the treatment of diseases including disseminated intravascular coagulation, shock, and pancreatitis. Since UTI synthesis is likely to be reduced in patients who have undergone liver resection, the incidence of inflammatory reactions may be increasing accordingly. For such patients, the liver enzyme increases after the operation can reflect liver damage. The purpose of this study was to examine if ulinastatin can inhibit liver enzyme increases after liver resection.

METHODS

After receiving Institutional Review Board approval, a retrospective chart review was performed on 201 patients who underwent hepatic resection from 2006 to 2010. We divided the records into the control (n = 69) and ulinastatin (n = 132) groups according to the use of intraoperative ulinastatin and compared the preoperative and postoperative laboratory test results. The number of patients who had > 400 U/L elevation of aspartate transaminase (AST) level after surgery was compared between the 2 groups.

RESULTS

The mean AST, alanine transaminase (ALT), and total bilirubin levels after liver resection were significantly lower in the ulinastatin group than in the control group. The number of patients who showed an AST > 400 U/L after liver resection was significantly higher in the control group (odds ratio = 3.02).

CONCLUSIONS

Ulinastatin attenuates the elevation of hepatic enzymes and bilirubin after liver resection.

Sequential intra-arterial therapy and portal vein embolization is feasible and safe in patients with advanced hepatic malignancies

BACKGROUND

A major hepatic resection for malignancies requires an adequate post-operative liver reserve. Portal vein embolization (PVE) with intra-arterial therapy (IAT) may increase future liver remnant (FLR) hypertrophy. As such, the feasibility, safety and efficacy of IAT+PVE were investigated.

METHODS

Between 2000 to 2011, 86 patients with malignancy of the liver were identified from a multi-institutional database. Twenty-nine patients underwent sequential IAT+PVE, 25 had PVE alone and 32 had IAT alone. Clinicopathological data were evaluated.

RESULTS

Most patients had hepatocellular carcinoma (HCC) (65.1%) and 31.4% had secondary metastatic disease. A complete or partial response using European Association for the Study of the Liver (EASLD) criteria was seen in 48.3% of patients undergoing IAT+PVE vs. 56.6% among patients undergoing IAT (P = 0.601). The median increase in percentage FLR volume was comparable in IAT+PVE (7.4%) vs. PVE only (7.9%) (P = 0.203). There were no IAT+PVE-associated deaths and only one complication. Among patients treated with IAT+PVE (n = 29), 27 underwent a subsequent hepatic resection. Peri-operative morbidity and mortality was 29.6% and 7.4%, respectively. Among the patients with HCC who underwent curative intent surgery after IAT+PVE, the median survival was 59.0 months.

CONCLUSIONS

Sequential IAT and PVE are feasible and safe. Utilization of IAT+PVE before a resection can lead to long-term survival and should be considered in the treatment of patients with advanced hepatic malignancies.

A comparison of indocyanine green fluorescence imaging plus blue dye and blue dye alone for sentinel node navigation surgery in breast cancer patients

PURPOSE

To evaluate two methods of sentinel node navigation surgery (SNNS) using blue dye with and without indocyanine green (ICG) fluorescence imaging (FI) to determine the usefulness of combined ICG and blue dye.

METHODS

Between 2005 and 2010, a total of 501 patients underwent SNNS in our hospital. Detection of sentinel lymph node (SLN) was performed with sulfan blue (SB) alone until 2008 and with a combination of SB and ICG-FI since 2009. ICG 5 mg and SB 15 mg were injected in the subareolar region, and FI was obtained by a fluorescence imaging device.

RESULTS

We attempted to identify SLNs in 393 patients by SB alone and in 108 patients by a combination of SB and FI. The mean number of SLNs detected was 1.6 (0-5) for SB alone and 2.2 (1-6) for the combination method. The SLN identification rate was 95.7 % for SB alone and 100 % for the combination method so that the combination was significantly superior to SB in terms of the identification rate (p = 0.0037). In patients who received the combination method, detection of SLN was made through only SB in 1 patient, only ICG in 8 patients, and both in 99 patients. Lymph node metastasis was found in 56 patients with SB alone and in 16 patients with the combination method. Recurrence of an axillary node was observed in 3 patients (0.8 %) with SB alone and in no patients with the combination method.

CONCLUSIONS

ICG-FI is a useful method and is especially recommended in cases where no radiotracers are available.

Routine anterior approach during right hepatectomy: results of a prospective randomised controlled trial

TRIAL DESIGN

A prospective randomised controlled trial was designed to evaluate the advantages of routine application of the anterior approach during right hepatectomy.

METHODS

The study was conducted between March 2005 and April 2009 in a tertiary hepatobiliary-pancreatic centre. Patients scheduled for right hepatectomy for primary or metastatic tumours, without infiltration of segment 1, inferior vena cava or main bile duct, were randomly assigned to right hepatectomy using either an anterior or a classic approach. The primary study endpoint was overall blood loss.

RESULTS

Sixty-six patients were randomly allocated to undergo right hepatectomy with an anterior (AA group n=33) or a classic approach (CA group n=33). Sixty-five patients were included in the analysis (33 in AA group and 32 in CA group). There was no significant difference in patient age, diagnosis, preoperative hepatic biochemistry and tumour size between the two groups. Overall blood loss (437 ml ± 664 in AA group vs.500 ml ± 532.3 in CA group; p=0.960) and bleeding during transection (p=0.973) were similar between two groups. Perioperative blood transfusion rates were 18% in the AA group and 9.3 % in the CA group (p=0.253). Time of parenchymal transsection was significantly longer in AA group (75.1 ± 26.6 min vs. 56.7 ± 17.5 min, p=0.01). There was no difference between both groups for postoperative prothrombin time, serum transaminase and total bilirubin levels. One patient died in each group (p=0.746). The two groups had similar morbidity rates.

CONCLUSION

Routine application of the anterior approach during right hepatectomy does not decrease intraoperative blood loss and morbidity rate.

Function and volume recovery after partial hepatectomy: influence of preoperative liver function, residual liver volume, and obesity

BACKGROUND

The regenerative capacity of the liver is an essential pre-condition for the successful application of partial hepatectomy. However, the actual kinetics of functional recovery remains unspecified and no adequate tool for its clinical monitoring has yet been available.

METHODS

Eighty-five patients receiving major hepatectomy were investigated from the preoperative evaluation until 12 weeks after surgery. Liver function was determined by the LiMAx test for the enzymatic capacity of cytochrome P450 1A2. Liver volume was determined by volumetric analysis of repeated computer tomography scans. Functional and volume recovery were compared during follow-up.

RESULTS

Major hepatectomy decreased liver function capacity to 35.7 ± 13.8% of preoperative function. It was shown that functional recovery already reaches 77.2 ± 33.5% of preoperative values within 10 days. The actual kinetics were dependent from the type and extent of hepatectomy. Complete functional restoration was achieved within 12 weeks, while liver volume still remained at 73.2 ± 14.8% of preoperative. A constant but interindividually variable correlation between function and volume was observed at all points in time.

CONCLUSION

Partial hepatectomy leads to fast and complete functional recovery, while volume recovery is delayed and remains often incomplete. The functional recovery is mainly influenced by the preoperative liver function, the residual liver volume, and by obesity.

Phenacetin O-deethylation is a useful tool for evaluation of hepatic functional reserve in rats with CCl(4)-induced chronic liver injury

BACKGROUND

Mortality of liver resection is as high as 3.1% to 25% in patients with chronic liver disease. Evaluation of hepatic functional reserve is critical for the prediction of risk of postoperation death. Phenacetin O-deethylation is a marker reaction of cytochrome P4501A2 (CYP1A2) activity. In this study, our aim is to investigate whether phenacetin O-deethylation is a useful tool for the evaluation of hepatic functional reserve in rats with chronic liver injury.

MATERIALS AND METHODS

Rat model for chronic liver injury was established by subcutaneous administration of 50% CCl(4), 1 mL/kg twice per week for 12 wk. Hepatic CYP1A2 activity, content, and mRNA expression were determined (n = 10). Effects of 15%, 30%, and 45% hepatectomy on phenacetin O-deethylation were evaluated in the rats (n = 5 in each group). Additionally, the correlation of risk of death after 70% hepatectomy with phenacetin O-deethylation was studied in 27 rats with chronic liver injury.

RESULTS

Compared with normal controls, CYP1A2 activity, content, and mRNA expression decreased 33%, 60%, and 50% in the rats with chronic liver injury (P < 0.05), respectively. Following the increasing of liver-resected size, CYP1A2 activity decreased proportionally (r(s) = -0.877, P < 0.05). Six of 27 rats with chronic liver injury died within 7 d after 70% hepatectomy. Phenacetin metabolism was impaired more severely in 6 rats that died than in 21 living rats (P < 0.05).

CONCLUSIONS

Phenacetin O-deethylation is a useful tool for the evaluation of hepatic functional reserve in the rats with CCl(4)-induced chronic liver injury.

Preoperative cognitive dysfunction is related to adverse postoperative outcomes in the elderly

BACKGROUND

Preoperative risk stratification is commonly performed by assessing end-organ function (such as cardiac and pulmonary) to define postoperative risk. Little is known about impaired preoperative cognition and outcomes. The purpose of this study was to evaluate the impact of baseline impaired cognition on postoperative outcomes in geriatric surgery patients.

STUDY DESIGN

Subjects 65 years and older undergoing a planned elective operation requiring postoperative ICU admission were recruited prospectively. Preoperative baseline cognition was assessed using the validated Mini-Cog test. Impaired cognition was defined as a Mini-Cog score of ≤ 3. Delirium was assessed using the Confusion Assessment Method-ICU by a trained research team. Adverse outcomes were defined using the Veterans Affairs Surgical Quality Improvement Program definitions.

RESULTS

One hundred and eighty-six subjects were included, with a mean age of 73 ± 6 years. Eighty-two subjects (44%) had baseline impaired cognition. The impaired cognition group had the following unadjusted outcomes: increased incidence of 1 or more postoperative complications (41% vs 24%; p = 0.011), higher incidence of delirium (78% vs 37%; p < 0.001), longer hospital stays (15 ± 14 vs 9 ± 9 days; p = 0.001), higher rate of discharge institutionalization (42% vs 18%; p = 0.001), and higher 6-month mortality (13% vs 5%; p = 0.040). Adjusting for potential confounders determined by univariate analysis, logistic regression found impaired cognition was still associated with the occurrence of 1 or more postoperative complications (odds ratio = 2.401; 95% CI, 1.185-4.865; p = 0.015). Kaplan-Meier survival analysis revealed higher mortality in the impaired cognition group (log-rank p = 0.008).

CONCLUSIONS

Baseline cognitive impairment in older adults undergoing major elective operations is related to adverse postoperative outcomes including increased complications, length of stay, and long-term mortality. Improved understanding of baseline cognition and surgical outcomes can aid surgical decision making in older adults.

Liver injury due to chemotherapy-induced sinusoidal obstruction syndrome is associated with sinusoidal capillarization

BACKGROUND

Indocyanine green (ICG) retention is a validated test of hepatic function in patients with chronic liver disease. The underlying mechanism for the impairment of ICG retention in patients undergoing chemotherapy for colorectal liver metastases (CLM) remains unclear. We sought to elucidate the mechanism for impairment of ICG retention in patients with CLM.

METHODS

Clinicopathologic data of 98 patients with CLM undergoing hepatectomy were analyzed. The archived nontumoral liver parenchyma bearing no CLM were immunostained with CD34 antibody to determine the sinusoidal capillarization.

RESULTS

Of 98 patients, 80 received preoperative chemotherapy. Sinusoidal obstruction syndrome (SOS) occurred in 39 patients (39.8%). The development of SOS in patients receiving oxaliplatin-based chemotherapy was significantly higher compared to those receiving non-oxaliplatin-based chemotherapy (P=0.003). SOS was independently associated with abnormal ICG retention rate at 15 minutes (ICG-R15) (odds ratio 3.45, 95% confidence interval 1.31-9.04, P=0.012) and CD 34 overexpression (odds ratio 18.76, 95% confidence interval 4.58-76.81, P<0.001). ICG-R15 correlated with CD34 expression within the nontumoral liver parenchyma (r=0.707, P<0.001) and severity of SOS (r=0.423, P<0.001). CD34 positive areas were likely situated at the peripheral area of SOS, and both SOS score and number of cycles of oxaliplatin-based chemotherapy significantly correlated with CD34 expression (r=0.629, P<0.001 and r=0.522, P<0.001, respectively).

CONCLUSIONS

These results suggest that the deterioration of hepatic functional reserve due to SOS is associated with sinusoidal capillarization, indicated by CD34 overexpression within nontumoral liver parenchyma adjacent to SOS.

The emerging role of transport systems in liver function tests

Liver function tests are of critical importance for the management of patients with severe or terminal liver disease. They are also used as prognostic tools for planning liver resections. In recent years many transport systems have been identified that also transport substances employed in liver function tests. Such substances include endogenous bilirubin or exogenously administered indocyanine green, agents for magnetic resonance imaging, agents for single photon emission computed tomography or agents for breath tests. The increasing functional and molecular information on the respective transport systems should improve the management and as a result the outcome of patients scheduled for liver surgery or transplantation. To achieve the latter goal, clinical studies that assess individual patients' liver function over the course of their disease with liver function tests are needed to firmly establish and validate recently introduced and novel liver function markers.

Serum albumin is present at higher levels in alcoholic liver cirrhosis as compared to HCV-related cirrhosis

Residual hepatic functional reserve in cirrhotic patients is generally evaluated by a multivariate scoring system (Child-Pugh classification), which includes serum albumin levels as a variable. However, several patients show discrepancies between serum albumin levels and the progression of liver fibrosis, especially those with alcoholic cirrhosis. To assess whether hepatic capacity of protein synthesis varies with the etiology of cirrhosis, serum albumin and cholinesterase levels, and prothrombin time were compared between alcoholic cirrhosis and hepatitis C virus (HCV)-related cirrhosis. To minimize the influence of malnutrition and extrahepatic platelet destruction, patients with hepatocellular carcinoma, uncontrolled diabetes, appetite loss and/or splenal longitudinal size >15 cm were excluded. The patients with compensated liver cirrhosis were divided into three groups as follows: alcohol(+)/HCV(+) (alcohol + HCV group; n=31), alcohol(-)/HCV(+) (HCV group; n=31) and alcohol(+)/HCV(-) (alcohol group; n=27). These groups were adjusted with respect to age, gender, body mass index and platelet count. Serum albumin levels in the alcohol group were significantly higher than those in the HCV group, with a difference of approximately 0.5 g/dl in every class of platelet count. The correlation of the alcohol + HCV group was intermediate between the alcohol and HCV groups. On the other hand, the correlations between serum cholinesterase levels and platelet counts were similar among the three groups. The prothrombin time was also comparable among the groups. Accordingly, serum albumin levels were higher in patients with alcoholic cirrhosis and alcohol consumption should be carefully considered when evaluating hepatic functional reserve.

The value of gadoxetate disodium-enhanced MR imaging for predicting posthepatectomy liver failure after major hepatic resection: a preliminary study

PURPOSE

To investigate whether preoperative gadoxetate-disodium-enhanced MR imaging predicts posthepatectomy liver failure (PHLF) in patients who underwent major hepatic resection.

MATERIALS AND METHODS

Twenty nine patients who underwent preoperative gadoxetate-disodium-enhanced MR imaging and following major hepatic resection were enrolled. Hepatic parenchymal signal intensity (SI) on pre-contrast T1-weighted imaging and 20min hepatocyte phase was measured at each of the four liver segments by two observers using region of interest measurements. The mean value was calculated and used at each phase. The relative contrast enhancement index (RCEI) was calculated: (20min hepatocyte phase SI-pre-contrast SI)/pre-contrast SI. PHLF was determined by the International Study Group of Liver Surgery 2011 guidelines. Correlation analysis was performed between preoperative liver function test and RCEI. Diagnostic accuracy of RCEI for predicting PHLF was calculated with receiver operating characteristic curve analysis. The reproducibility of the RCEI measurement was evaluated.

RESULTS

There was a significant correlation between preoperative albumin (r=0.496, P=0.006), T-bilirubin (r=-0.383, P=0.041), and RCEI. Seven patients (24%) experienced PHLF, and one of these patients (3%) died. The diagnostic accuracy of RCEI was 0.838 (sensitivity 85.7%, specificity 77.3%, cut-off value: 0.7508, 95% confidence interval: 0.654, 0.947). The 95% limits of agreement and ICC between repeated RCEI measurements were 18.4% of the mean and 0.94, respectively, and between RCEI measurements by the two observers were 21.7% and 0.929, respectively.

CONCLUSION

Our results show that preoperative gadoxetate-disodium-enhanced MR imaging can predict PHLF in patients who underwent major hepatic resection.

Cluster analysis of indicators of liver functional and preoperative low branched-chain amino acid tyrosine ration indicate a high risk of early recurrence in analysis of 165 hepatocellular carcinoma patients after initial hepatectomy

BACKGROUND

Cluster analysis is used for dividing many prognostic indicators, including liver function, tumor progression, and operative variables, into specific clusters. The albumin (ALB), hepatocyte growth factor (HGF), and branched chain amino-acid to tyrosine ratio (BTR) may represent the severity of liver disease and function of the hepatic reserve. We developed the ALB-BTR and HGF-BTR classifications depending on each level to find specific unique subgroups. Our aim was to identify specific subgroups destined for favorable and poor prognoses after initial hepatectomy.

METHODS

Between 2002 and 2008, 165 patients were analyzed retrospectively. Liver function indicators, including BTR, tumor-related factors, and operative variables, were evaluated by cluster analysis with Ward's criterion. The ALB-BTR classification was divided into 4 groups depending on ALB (cutoff value, 4.0 g/dL) and BTR (cutoff value, 6.0). The HGF-BTR classification was also divided into 4 groups depending on HGF (cutoff value, 0.35 ng/mL) and BTR (cutoff value, 6.0). The prognoses of the subgroups were compared by the log-rank test.

RESULTS

Cluster analysis divided multiple indicators into 5 different clusters. In each cluster, we further analyzed subgroups using the ALB-BTR and HGF-BTR classification. Mean recurrence-free survival times in ALB-GI (19.1 ± 2.4 months) and HGF-GIII (29.4 ± 3.8 months) were less than their mean overall survival times.

CONCLUSION

Cluster analysis is useful to find similar and different indicators. Even though liver function was well preserved, low BTR could identify early recurrence in hepatocellular carcinoma patients after resection.

Importance of low preoperative platelet count in selecting patients for resection of hepatocellular carcinoma: a multi-institutional analysis

BACKGROUND

Low platelet count is a marker of portal hypertension but is not routinely included in the standard preoperative evaluation of patients with hepatocellular carcinoma (HCC) because it pertains to liver function (Child/model for end-stage liver disease [MELD] score) and tumor burden (Milan criteria). We hypothesized that low platelet count would be independently associated with increased perioperative morbidity and mortality after resection.

STUDY DESIGN

Patients treated with liver resection for HCC between January 2000 and January 2010 at 3 institutions were eligible. Preoperative platelet count, Child/MELD score, and tumor extent were recorded. Low preoperative platelet count (LPPC) was defined as <150 × 10(3)/μL. Postoperative liver insufficiency (PLI) was defined as peak bilirubin >7 mg/dL or development of ascites. Univariate and multivariate regression was performed for predictors of major complications, PLI, and 60-day mortality.

RESULTS

A total of 231 patients underwent resection, of whom 196 (85%) were classified as Child A and 35 (15%) as Child B; median MELD score was 8. Overall, 168 (71%) had tumors that exceeded Milan criteria and 134 (58%) had major hepatectomy (≥3 Couinaud segments). Overall and major complication rates were 55% and 17%, respectively. PLI occurred in 25 patients (11%), and 21 (9%) died within 60 days of surgery. Patients with LPPC (n = 50) had a significantly increased number of major complications (28% versus 14%, p = 0.031), PLI (30% versus 6%, p = 0.001), and 60-day mortality (22% versus 6%, p = 0.001). When adjusted for Child/MELD score and tumor burden, LPPC remained independently associated with increased number of major complications (odds ratio [OR] 2.8, 95% confidence intervals [CI] 1.1 to 6.8, p = 0.026), PLI (OR 4.0, 95% CI 1.4 to 11.1, p = 0.008), and 60-day mortality (OR 4.6, 95% CI 1.5 to 14.6, p = 0.009).

CONCLUSIONS

LPPC is independently associated with increased major complications, PLI, and mortality after resection of HCC, even when accounting for standard criteria, such as Child/MELD score and tumor extent, used to select patients for resection. Patients with LPPC may be better served with transplantation or liver-directed therapy.

Prediction of indocyanine green retention rate at 15 minutes by correlated liver function parameters before hepatectomy

BACKGROUND

Indocyanine green retention rate at 15 min (ICGR15) is a useful marker of liver function in deciding on the extent of hepatectomy. To determine ICGR15 regardless of liver condition, we sought to establish a formula for converted ICGR15 based on conventional blood tests and technetium-99 m galactosyl human serum albumin ((99m)Tc-GSA) scintigraphy.

MATERIALS AND METHODS

We measured liver function parameters, including ICGR15, in 307 patients, including 265 liver cancer patients without biliary obstruction (no obstruction group) and 42 with biliary obstruction (obstruction group).

RESULTS

In the no obstruction group, multiple regression analysis identified blood pool clearance ratio (HH15), liver uptake ratio (LHL15) calculated by heart and liver activity between 3 and 15 min after injection of (99m)Tc-GSA, and serum hyaluronic acid as significant correlates (P < 0.05). The calculated converted ICGR15 was then equal to 0.02∗HA + 0.276∗(HH15∗100)-0.501∗(LHL15∗100) + 41.41. The mean difference between actual and converted ICGR15 was significantly lower in the obstruction than in the no obstruction group (P = 0.031). A significantly larger proportion of patients of the obstruction group had lower converted ICGR15 than those of the no obstruction group (P = 0.045).

CONCLUSION

The converted ICGR15 is useful for evaluating hepatic function in patients with biliary obstruction who plan to undergo major hepatectomy.

Hepatectomy preoperative planning

Hepatectomy can comprise excision of peripheral tumors as well as major surgeries like trisegmentectomies or central resections. Patients can be healthy, have localized liver disease or possess a cirrhotic liver with high operative risk. The preoperative evaluation of the risk of postoperative liver failure is critical in determining the appropriate surgical procedure. The nature of liver disease, its severity and the operation to be performed should be considered for correct preparation. Liver resection should be evaluated in relation to residual parenchyma, especially in cirrhotic patients, subjects with portal hypertension and when large resections are needed. The surgeon should assess the rationale for the use of hepatic volumetry. Child-Pugh, MELD and retention of indocyanine green are measures for assessing liver function that can be used prior to hepatectomy. Extreme care should be taken regarding the possibility of infectious complications with high morbidity and mortality in the postoperative period. Several centers are developing liver surgery in the world, reducing the number of complications. The development of surgical technique, anesthesia, infectious diseases, oncology, intensive care, possible resection in patients deemed inoperable in the past, will deliver improved results in the future.

Correlation of Kupffer cell function and hepatocyte function in chronic viral hepatitis evaluated with superparamagnetic iron oxide-enhanced magnetic resonance imaging and scintigraphy using technetium-99m-labelled galactosyl human serum albumin

Kupffer cells contribute to the pathogenesis of liver injury in chronic liver disease, yet it is difficult to assess Kupffer cell function either ex vivo or in vivo, since supporting data are limited. The aim of this study was to clarify the relation between Kupffer cell function and hepatocyte function by analyzing the correlation between conventional indices of hepatic functional reserve and both superparamagnetic iron oxide-enhanced MRI (SPIO-MRI) and technetium-99m-galactosyl human serum albumin scintigraphy (Tc-99m-GSA) in patients with chronic viral hepatitis. Consecutive 46 patients (16 patients with chronic hepatitis and 30 patients with cirrhosis) who underwent both SPIO-MRI and Tc-99m-GSA were examined. The patients were aged 46-83 years (median 70) and included 29 men and 17 women. Spearman correlation coefficient was used to analyze the correlations between functional reserve indices and both reduction percentages of liver-to-muscle signal intensity ratio (reduction-%LMR), as a surrogate parameter of Kupffer cell function and Tc-99m-GSA parameters. The usefulness of each parameter as a marker to differentiate Child-Pugh A from Child-Pugh B/C was evaluated using receiver operating characteristic (ROC) analysis. The reduction-%LMR correlated more closely with Child-Pugh score (r=0.77; P<0.001) than did Tc-99m-GSA parameters. For predicting Child-Pugh B/C, ROC analysis revealed that reduction-%LMR (AUC=0.91, P<0.001) was the most useful parameter and at a cutoff value of 50% or less, sensitivity, specificity, positive and negative predictive values were 0.79, 0.91, 0.94 and 0.71, respectively. SPIO-MRI may be a helpful non-invasive method for the evaluation of hepatic functional reserve, and this study suggests that Kupffer cell function is closely correlated with hepatocyte function in patients with chronic viral hepatitis.

Importance of low preoperative platelet count in selecting patients for resection of hepatocellular carcinoma: a multi-institutional analysis

BACKGROUND

Low platelet count is a marker of portal hypertension but is not routinely included in the standard preoperative evaluation of patients with hepatocellular carcinoma (HCC) because it pertains to liver function (Child/model for end-stage liver disease [MELD] score) and tumor burden (Milan criteria). We hypothesized that low platelet count would be independently associated with increased perioperative morbidity and mortality after resection.

STUDY DESIGN

Patients treated with liver resection for HCC between January 2000 and January 2010 at 3 institutions were eligible. Preoperative platelet count, Child/MELD score, and tumor extent were recorded. Low preoperative platelet count (LPPC) was defined as <150 × 10(3)/μL. Postoperative liver insufficiency (PLI) was defined as peak bilirubin >7 mg/dL or development of ascites. Univariate and multivariate regression was performed for predictors of major complications, PLI, and 60-day mortality.

RESULTS

A total of 231 patients underwent resection, of whom 196 (85%) were classified as Child A and 35 (15%) as Child B; median MELD score was 8. Overall, 168 (71%) had tumors that exceeded Milan criteria and 134 (58%) had major hepatectomy (≥3 Couinaud segments). Overall and major complication rates were 55% and 17%, respectively. PLI occurred in 25 patients (11%), and 21 (9%) died within 60 days of surgery. Patients with LPPC (n = 50) had a significantly increased number of major complications (28% versus 14%, p = 0.031), PLI (30% versus 6%, p = 0.001), and 60-day mortality (22% versus 6%, p = 0.001). When adjusted for Child/MELD score and tumor burden, LPPC remained independently associated with increased number of major complications (odds ratio [OR] 2.8, 95% confidence intervals [CI] 1.1 to 6.8, p = 0.026), PLI (OR 4.0, 95% CI 1.4 to 11.1, p = 0.008), and 60-day mortality (OR 4.6, 95% CI 1.5 to 14.6, p = 0.009).

CONCLUSIONS

LPPC is independently associated with increased major complications, PLI, and mortality after resection of HCC, even when accounting for standard criteria, such as Child/MELD score and tumor extent, used to select patients for resection. Patients with LPPC may be better served with transplantation or liver-directed therapy.

Virtual liver resection and volumetric analysis of the future liver remnant using open source image processing software

BACKGROUND

After extended liver resection, a remnant liver that is too small can lead to postresection liver failure. To reduce this risk, preoperative evaluation of the future liver remnant volume (FLRV) is critical. The open-source OsiriX PAC software system can be downloaded for free and used by nonradiologists to calculate liver volume using a stand-alone Apple computer. The purpose of this study was to assess the accuracy of OsiriX CT volumetry for predicting liver resection volume and FLVR in patients undergoing partial hepatectomy.

METHODS

Preoperative contrast-enhanced liver CT scans of patients who underwent partial hepatectomy were analyzed by three observers. Two surgical trainees measured the total liver volume, resection volume, and tumor volume using OsiriX, and a radiologist measured these volumes using CT scanner-linked Aquarius iNtuition software. Resection volume was correlated with prospectively determined resection weight, and differences in the measured liver volumes were analyzed. Interobserver variability was assessed using Bland-Altman plots.

RESULTS

25 patients (M/F ratio: 13/12) with a median age of 61 (range, 34-77) years were included. There were significant correlations between the weight and volume of the resected specimens (Pearson's correlation coefficient: R(2) = 0.95). There were no major differences in total liver volumes, resection volumes, or tumor volumes for observers 1, 2, and 3. Bland-Altman plots showed a small interobserver variability. The mean time to complete liver volumetry for one patient using OsiriX was 19 +/- 3 min.

CONCLUSIONS

OsiriX liver volumetry performed by surgeons is an accurate and time-efficient method for predicting resection volume and FLRV.

A fourth dimension in decision making in hepatology

Today, the assessment of liver function in patients suffering from acute or chronic liver disease is based on liver biopsy and blood tests including synthetic function, liver enzymes and viral load, most of which provide only circumstantial evidence as to the degree of hepatic impairment. Most of these tests lack the degree of sensitivity to be useful for follow-up of these patients at the frequency that is needed for decision making in clinical hepatology. Accurate assessment of liver function is essential to determine both short- and long-term prognosis, and for making decisions about liver and non-liver surgery, TIPS, chemoembolization or radiofrequency ablation in patients with chronic liver disease. Liver function tests can serve as the basis for accurate decision-making regarding the need for liver transplantation in the setting of acute failure or in patients with chronic liver disease. The liver metabolic breath test relies on measuring exhaled (13) C tagged methacetin, which is metabolized only by the liver. Measuring this liver-specific substrate by means of molecular correlation spectroscopy is a rapid, non-invasive method for assessing liver function at the point-of-care. The (13) C methacetin breath test (MBT) is a powerful tool to aid clinical hepatologists in bedside decision-making. Our recent findings regarding the ability of point-of-care (13) C MBT to assess the hepatic functional reserve in patients with acute and chronic liver disease are reviewed along with suggested treatment algorithms for common liver disorders.

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI

OBJECTIVES

Gd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified.

METHODS

Gd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (C(max) , T(max) and T(1/2) ), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM).

RESULTS

Although the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child-Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child-Pugh scores.

CONCLUSIONS

Dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels.

Serum markers of hepatocellular carcinoma

BACKGROUND

The hepatocellular carcinoma is one of the most common malignant tumors and carries a poor survival rate. The management of patients at risk for developing HCC remains intricate.

METHODS

A literature search identified potential markers for hepatocellular carcinoma. These markers were analysed and justification was provided for these factors' inclusion to (or exclusion from) the markers of hepatocellular carcinoma (HCC). A search of the literature was made using cancer literature and the PubMed database for the following keywords: "markers and HCC," "Lens culinaris agglutinin reactive AFP (AFP-L3) and HCC," "Des-γ-carboxy prothrombin (DCP) and HCC," "Glypican-3 and HCC," "Chromogranin A and HCC," "Transforming growth factor β1(TGF) and HCC," "α-l-fucosidase (AFU) and HCC," "Golgi protein-73 (GP73) and HCC," "Hepatocyte growth factor (HGF) and HCC," "Nervous growth factor (NGF) and HCC."

CONCLUSIONS

Despite the large number of studies devoted to the immunohistochemistry of HCC, at the present time, the absolute positive and negative markers for HCC are still lacking, and even those characterized by very high sensitivity and specificity do not have an universal diagnostic usefulness. Given the poor response to current therapies, a better understanding of the molecular pathways active in this disease could potentially provide new targets for therapy. However, AFP shows a low sensitivity, therefore other biomarkers have been developed to make an early diagnosis and improve patients' prognosis.

Can preoperative diffusion-weighted MRI predict postoperative hepatic insufficiency after curative resection of HBV-related hepatocellular carcinoma? A pilot study

Liver fibrosis determines the functional liver reserve. Several studies have reported that the apparent diffusion coefficient (ADC) values of diffusion-weighted magnetic resonance imaging (DW-MRI) can assess liver fibrosis. We investigated whether DW-MRI predicts postoperative hepatic insufficiency and liver fibrosis in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Twenty-six patients with HBV-related HCC who received preoperative DW-MRI on a 3-T MRI system were enrolled between July and December 2008. ADC values were measured twice by two observers. Three "b values" were used: 50, 400 and 800 s/mm(2). Postoperative hepatic insufficiency was defined as persistent hyperbilirubinemia (total bilirubin level >5 mg/dl for more than 5 days after surgery) or postoperative death without other causes. The mean age (21 men and 5 women) was 51.4 years. Three patients experienced postoperative hepatic insufficiency. liver stiffness measurement predicted postoperative hepatic insufficiency, advanced fibrosis (F3-4), and cirrhosis significantly [area under the receiving operator characteristic curve (AUROC)=0.942, 0.771 and 0.818, respectively, with P=.047, 0.048 and 0.006, respectively]; ADC values of DW-MRI, however, did not (AUROC=0.797, 0.648 and 0.491, respectively, with P=.100, 0.313 and 0.938, respectively). Reliability of ADC values between right and left hepatic lobes (rho=0.868 and rho=0.910 in the first and second measures of Observer A; rho=0.865 and rho=0.831 in the first and second measures of Observer B) was high and the intra- and interobserver reliability (rho=0.958 in observer A and rho=0.977 in observer B; rho=0.929 in the first measure and rho=0.978 in the second measure between the two observers) were high. All reliability was significant (P<.001). Our results suggest that DW-MRI on a 3-T MRI system is not suitable for predicting postoperative hepatic insufficiency, advanced liver fibrosis, and cirrhosis in patients with HBV-related HCC, despite significantly high reliability.

Preoperative estimation of remnant hepatic function using fusion images obtained by (99m)Tc-labelled galactosyl-human serum albumin liver scintigraphy and computed tomography

BACKGROUND

Assessment of hepatic functional reserve is important in hepatic resection. The aim of this study was to evaluate the role of hepatic asialoglycoprotein receptor (ASGP-R) analysis in the preoperative estimation of remnant liver function in liver surgery.

METHODS

One hundred and one patients undergoing hepatic resection for liver tumours were studied. Seventeen patients had preoperative percutaneous transhepatic portal vein embolization (PTPE). Function of the hepatic remnant was estimated before surgery using radioactivity in fusion images of both liver single-photon emission computed tomography and computed tomography scans using (99m)Tc-labelled diethylene triamine penta-acetate-galactosyl-human serum albumin.

RESULTS

All three patients with an ASGP-R concentration below 400 nmol/l and preoperative total amount of receptor in the future remnant liver (R0-remnant) of less than 53.0 nmol per liver died. Two patients with chronic hepatitis and R0-remnant values between 53.0 and 65.0 nmol per liver and a receptor concentration lower than 600 nmol/l developed liver dysfunction. The incidence of liver failure decreased inversely with increasing R0-remnant value.

CONCLUSION

A combination of receptor concentration and the amount of hepatic receptor in the future liver remnant as detected on fusion images is useful in evaluating the risk of postoperative liver failure.

Nuclear imaging techniques for the assessment of hepatic function in liver surgery and transplantation

This review describes the application of 2 nuclear imaging techniques for assessment of hepatic function in the setting of liver surgery and transplantation. The biochemical and technical background, as well as the clinical applications, of (99m)Tc-labeled diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) scintigraphy and hepatobiliary scintigraphy (HBS) with (99m)Tc-labeled iminodiacetic acid derivates is discussed. (99m)Tc-mebrofenin is considered the most suitable iminodiacetic acid agent for (99m)Tc-HBS. (99m)Tc-GSA scintigraphy and (99m)Tc-mebrofenin HBS are based on 2 different principles. (99m)Tc-GSA scintigraphy is a receptor-mediated technique whereas HBS represents hepatic uptake and excretion function. Both techniques are noninvasive and provide visual and quantitative information on both total and regional liver function. They can be used for preoperative assessment of future remnant liver function, follow-up after preoperative portal vein embolization, and evaluation of postoperative liver regeneration. In liver transplantation, these methods are used to assess graft function and biliary complications.

Natural course of the remnant hepatic functional reserve as estimated by technetium-99m-galactosyl human serum albumin scintigraphy after a hepatectomy

BACKGROUND

Technetium-99m-galactosyl human serum albumin (GSA) scintigraphy provides an accurate estimation of the hepatic functional reserve but is not applied after a hepatectomy. The aim of this study was to elucidate the natural course of the remnant hepatic functional reserve (RHFR) after hepatectomy by GSA scintigraphy.

METHODS

Eighty-six patients (partial hepatic resection, Hr0 = 46; sectionectomy, Hr1 = 21; bisectionectomy, Hr2 = 19) classified as Child-Pugh class A before the hepatectomy were enrolled, and GSA scintigraphy to detect HH15 (uptake ratio of the heart at 15 min to that at 3 min) and LHL15 (uptake ratio of the liver at 15 min to the liver plus the heart at 15 min) was performed periodically before and after the hepatectomy. HH15, LHL15, and the percentages of patients that recovered to the preoperative levels of these entities were estimated. In addition, hematobiochemical tests and the remnant liver volume were also periodically monitored.

RESULTS

HH15 and LHL15 levels deteriorated until 2 months postoperatively (PO) after the procedure and subsequently recovered to the preoperative levels at 6 months PO in Hr0 patients. In Hr1 patients, but not in Hr2 patients, these levels also deteriorated until 3 months PO and had improved by 6 months after the surgery. Only 40% of the patients showed recovery to the preoperative levels by 6 months PO in the Hr0 group; furthermore, the percentage of patients who showed recovery to the preoperative levels by 6 months PO was under 40% in the Hr1 group and around 10% in the Hr2 group. However, the results of hematobiochemical tests and the remnant liver volume in all types of hepatectomies were rapidly normalized after the hepatectomy.

CONCLUSIONS

Remnant hepatic functional reserve estimated by GSA scintigraphy revealed that a larger resected liver volume induced both more serious and continued remnant hepatic dysfunction in comparison to results shown by hematobiochemical tests, while the functional regeneration was also appreciably slower and more gradual in comparison to the volume regeneration.

The LiMAx test: a new liver function test for predicting postoperative outcome in liver surgery

BACKGROUND

Liver failure has remained a major cause of mortality after hepatectomy, but it is difficult to predict preoperatively. This study describes the introduction into clinical practice of the new LiMAx test and provides an algorithm for its use in the clinical management of hepatic tumours.

METHODS

Patients with hepatic tumours and indications for hepatectomy were investigated perioperatively with the LiMAx test. In one patient, analysis of liver volume was carried out with preoperative three-dimensional virtual resection.

RESULTS

A total of 329 patients with hepatic tumours were evaluated for hepatectomy. Blinded preoperative LiMAx values were significantly higher before resection (n= 139; mean 351 microg/kg/h, range 285-451 microg/kg/h) than before refusal (n= 29; mean 299 microg/kg/h, range 223-376 microg/kg/h; P= 0.009). In-hospital mortality rates were 38.1% (8/21 patients), 10.5% (2/19 patients) and 1.0% (1/99 patients) for postoperative LiMAx of <80 microg/kg/h, 80-100 microg/kg/h and >100 microg/kg/h, respectively (P < 0.0001). A decision tree was developed to avoid critical values and its prospective preoperative application revealed a reduction in mortality from 9.4% to 3.4% (P= 0.019).

DISCUSSION

The LiMAx test can validly determine liver function capacity and is feasible in every clinical situation. Combination with virtual resection could enable the calculation of residual liver function. The LiMAx decision tree algorithm for hepatectomy might significantly improve preoperative evaluation and postoperative outcome in liver surgery.

Two-step synthesis of galactosylated human serum albumin as a targeted optical imaging agent for peritoneal carcinomatosis

An optical probe, RG-(gal)(28)GSA, was synthesized to improve the detection of peritoneal implants by targeting the beta-d-galactose receptors highly expressed on the cell surface of a wide variety of cancers arising from the ovary, pancreas, colon, and stomach. Evaluation of RG-(gal)(28)GSA, RG-(gal)(20)GSA, glucose-analogue RG-(glu)(28)GSA, and control RG-HSA demonstrates specificity for the galactose, binding to several human adenocarcinoma cell lines, and cellular internalization. Studies using peritoneally disseminated SHIN3 xenografts in mice also confirmed a preference for galactose with the ability to detect submillimeter size lesions. Preliminary toxicity study for RG-(gal)(28)GSA using Balb/c mice reveal no toxic effects up to 100x of the standard imaging dose of 1 mg/kg administered either intraperitoneally or intravenously. These data indicate that RG-(gal)(28)GSA can selectively target a variety of human adenocarcinomas, can improve intraoperative or endoscopic tumor detection and resection, and may have little or no toxic in vivo effects; hence, it may be clinically translatable.

Liver parenchymal enhancement of hepatocyte-phase images in Gd-EOB-DTPA-enhanced MR imaging: which biological markers of the liver function affect the enhancement?

PURPOSE

To clarify the factors that predict enhancement of the liver parenchyma in hepatocyte-phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging.

MATERIALS AND METHODS

Gd-EOB-DTPA-enhanced hepatocyte-phase MR images of 198 patients with chronic liver diseases (Child-Pugh class A in 112 patients, class B in 74 patients, and class C in 12 patients) were retrospectively analyzed. The hepatocyte-phase images were obtained using fat-suppressed T1-weighted gradient-echo images with a 3D acquisition sequence 10 min and 20 min after IV administration of Gd-EOB-DTPA (0.025 mmol/kg body weight). The quantitative liver-spleen contrast ratio (Q-LSC) was calculated using the signal intensities of the liver and spleen. Serum albumin levels, total bilirubin levels, prothrombin activity, and the results of indocyanine green clearance tests (ICGs) were recorded and correlated with the Q-LSC. Logistic regression analysis was performed to analyze which factors predict sufficient liver enhancement using a Q-LSC of 1.5 as a cutoff value.

RESULTS

Only ICGs and Child-Pugh classifications showed a statistically significant correlation with the Q-LSC. Logistic regression analysis showed that ICGs were the only factors that accurately predicted liver enhancement on hepatocyte-phase images.

CONCLUSION

ICGs were found to be predictors of sufficient liver enhancement on hepatocyte-phase images.

Perioperative mortality for management of hepatic neoplasm: a simple risk score

OBJECTIVES

To develop a population-based risk score for stratifying patients by risk of in-hospital mortality following procedural intervention for hepatic neoplasm.

BACKGROUND

There has been growing support for the value of surgical management of hepatic neoplastic disease, both primary and metastatic. Advances in surgical and ablative technologies have contributed to a decrease in the mortality associated with these procedures. However, multiple patient-, disease- and treatment-related factors can contribute to perioperative morbidity and mortality.

METHODS

Using the Nationwide Inpatient Sample from 1998 to 2005, a retrospective cohort of patient-discharges for hepatic procedures with a concurrent diagnosis of hepatic primary or metastatic neoplasm to the liver was assembled. Procedures were categorized as lobectomy, wedge resection, or enucleation/ablation. Logistic regression and bootstrap methods were used to create an integer score for estimating the risk of in-hospital mortality using patient demographics, comorbidities, procedure type, tumor type, and hospital characteristics. A randomly selected sample of 80% of the cohort was used to create the risk score. Testing was conducted in the remaining 20% validation-set.

RESULTS

In total, 12,969 patient-discharges were identified. Overall in-hospital mortality was 3.45%. Predictive characteristics incorporated into the model included: age, sex, Charlson comorbidity score, procedure type, hospital type, and type of neoplasm. Integer values were assigned to these, and used to calculate an additive score. Five clinically relevant groups were assembled to stratify risk, with a 36-fold gradient in mortality. Rates in the groups were as follows: 0.9%, 2.5%, 6.8%, 17.6%, and 35.9%. In the derivation set, as well as in the validation set, the simple score discriminated well, with c-statistics of 0.76 and 0.70, respectively.

CONCLUSIONS

An integer-based risk score can be used to predict in-hospital mortality after hepatic procedure for neoplasm, and may be useful for preoperative risk stratification and patient counseling.

Surgery in the patient with liver disease

Liver dysfunction is a prominent entity in Western medicine that has historically affected patients suffering from chronic viral or alcoholic hepatitis. The incidence of these conditions has not changed dramatically in recent years but the overall number of patients with liver dysfunction has increased considerably with the emergence of the obesity epidemic. Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of chronic liver disease in the United States. Although the rate of progression of NAFLD to overt cirrhosis is low, the high prevalence of this condition, combined with the moderate degree of liver dysfunction it engenders, has resulted in a significant increase in the number of patients with liver disease that can be encountered by a surgical practice. Any degree of clinically evident liver disease in a prospective surgical patient should raise concern for the entire surgical team. This particularly applies to intraabdominal surgery whereby the presence of hepatomegaly, portal hypertension, variceal bleeding, and ascites can turn even the most routine operation into a morbid and life-threatening procedure. Nonabdominal surgery avoids some of the technical challenges presented by liver disease but the anesthetic management of a cirrhotic patient still makes any operation potentially more dangerous. In this article, approaches to minimize the risk when surgery becomes necessary in the presence of liver disease are discussed.

Surgery in the patient with liver disease

Liver dysfunction is a prominent entity in Western medicine that has historically affected patients suffering from chronic viral or alcoholic hepatitis. The incidence of these conditions has not changed dramatically in recent years but the overall number of patients with liver dysfunction has increased considerably with the emergence of the obesity epidemic. Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of chronic liver disease in the United States. Although the rate of progression of NAFLD to overt cirrhosis is low, the high prevalence of this condition, combined with the moderate degree of liver dysfunction it engenders, has resulted in a significant increase in the number of patients with liver disease that can be encountered by a surgical practice. Any degree of clinically evident liver disease in a prospective surgical patient should raise concern for the entire surgical team. This particularly applies to intraabdominal surgery whereby the presence of hepatomegaly, portal hypertension, variceal bleeding, and ascites can turn even the most routine operation into a morbid and life-threatening procedure. Nonabdominal surgery avoids some of the technical challenges presented by liver disease but the anesthetic management of a cirrhotic patient still makes any operation potentially more dangerous. In this article, approaches to minimize the risk when surgery becomes necessary in the presence of liver disease are discussed.

Prediction of postoperative outcome after hepatectomy with a new bedside test for maximal liver function capacity

OBJECTIVE

To validate the LiMAx test, a new bedside test for the determination of maximal liver function capacity based on C-methacetin kinetics. To investigate the diagnostic performance of different liver function tests and scores including the LiMAx test for the prediction of postoperative outcome after hepatectomy.

SUMMARY BACKGROUND DATA

Liver failure is a major cause of mortality after hepatectomy. Preoperative prediction of residual liver function has been limited so far.

METHODS

Sixty-four patients undergoing hepatectomy were analyzed in a prospective observational study. Volumetric analysis of the liver was carried out using preoperative computed tomography and intraoperative measurements. Perioperative factors associated with morbidity and mortality were analyzed. Cutoff values of the LiMAx test were evaluated by receiver operating characteristic.

RESULTS

Residual LiMAx demonstrated an excellent linear correlation with residual liver volume (r = 0.94, P < 0.001) after hepatectomy. The multivariate analysis revealed LiMAx on postoperative day 1 as the only predictor of liver failure (P = 0.003) and mortality (P = 0.004). AUROC for the prediction of liver failure and liver failure related death by the LiMAx test was both 0.99. Preoperative volume/function analysis combining CT volumetry and LiMAx allowed an accurate calculation of the remnant liver function capacity prior to surgery (r = 0.85, P < 0.001).

CONCLUSIONS

Residual liver function is the major factor influencing the outcome of patients after hepatectomy and can be predicted preoperatively by a combination of LiMAx and CT volumetry.

The costs of postoperative liver failure and the economic impact of liver function capacity after extended liver resection--a single-center experience

PURPOSE

Postoperative liver failure (PLF) is a relatively frequent and life-threatening complication after extended liver resection. This study describes the economic burden of PLF from the hospitals' perspective and explores the role of liver function capacity.

MATERIALS AND METHODS

Economic data of total costs and cost distribution were analyzed for 48 patients who had participated in a prospective study with the LiMAx test, a novel test for liver function capacity. For this population, detailed individual data were available. The economic data were analyzed and adjusted for relevant covariates. In addition, economic data of 916 patients who had undergone liver resection during 2005-2007 were retrieved from the hospitals' medical controlling office for comparison.

RESULTS

A significant difference between the costs of patients with regular recovery (25,980 Euro [95% confidence interval (95%CI) = 9,559 to 42,401]) versus patients developing PLF (82,199 Euro [95%CI = 42,812 to 121,586]; p = 0.013) was observed. The mean additional costs of PLF were 56,219 Euro. An equivalent cost difference of mortality was obtained from the analysis of 916 patients. Patients developing PLF had a decreased LiMAx of 61 microg/kg/h compared to the regular group 122 microg/kg/h (p < 0.001) after surgery. Initial postoperative LiMAx and total costs revealed a linear correlation coefficient of r = -0.340 (p = 0.018).

CONCLUSIONS

PLF is a very relevant medical and economic problem. Liver function capacity does not only predict PLF but also correlates with total costs in general.

Real-time intraoperative assessment of residual liver functional reserve using pulse dye densitometry

BACKGROUND

For a safe major hepatectomy, preoperative methods that can reliably estimate postoperative liver function are necessary. The aim of this study was to assess the utility of ICG-R15 measured by pulse dye densitometry to predict residual liver function prior to hepatectomy.

PATIENTS AND METHOD

In 29 patients who underwent various types of hepatectomies, indocyanine green (ICG)-R15 was measured by pulse dye densitometry at the time of opening the abdomen (laparotomy phase), clamping the Glisson's pedicles to cutting (clamping phase), and closing abdomen after hepatectomy (resection phase). The relationships among these measurements and postoperative liver function were examined.

RESULTS

The mean ICG-R15 was 12.3 +/- 6.0% preoperatively (+/-SD), 9.3 +/- 7.0% at laparotomy, 18.8 +/- 11.6% at clamping, and 20.1 +/- 10.9% at resection. The preoperative and laparotomy and the clamping and resection ICG-R15 values correlated significantly. Eleven (38%) patients developed postoperative hyperbilirubinemia [total bilirubin (T-Bil) >3.0 mg/dl]. The postoperative peak T-Bil correlated significantly with clamping ICG-R15 (r = 0.637, p = 0.0002), but not with preoperative ICG-R15 (r = 0.283, p = 0.137), total clamp time (r = 0.005, p = 0.975), and blood loss (r = 0.097, p = 0.615). Multivariate analysis identified ICG-R15 measured at clamping as the only determinant of postoperative peak T-Bil (r = 0.612). ICG-R15 measured at clamping correlated with the postoperative hospital stay (p = 0.046).

CONCLUSIONS

ICG-R15 can be measured in real time during surgery by pulse dye densitometry. ICG-R15 measured by this technique before hepatectomy provides a direct and reliable measure of postoperative residual liver function, thus helping in surgical decision making regarding the extent of hepatectomy.