Body mass index as a predictor of hepatic steatosis in living liver donors

The impact of diet-induced hepatic steatosis in a murine model of hepatic ischemia/reperfusion injury

The prevalence of obesity-associated nonalcoholic fatty liver disease has significantly increased over the past decade, and end-stage liver disease secondary to nonalcoholic steatohepatitis has become 1 of the most common indications for liver transplantation. This both increases the demand for organs and decreases the availability of donor livers deemed suitable for transplantation. Although in the past many steatotic livers were discarded due to concerns over enhanced susceptibility to ischemia/reperfusion injury (IRI) and organ failure, the discrepancy between supply and demand has resulted in increasing use of expanded criteria donor organs including steatotic livers. However, it remains controversial whether steatotic livers can be safely used for transplantation and how best to improve the performance of steatotic grafts. We aimed to evaluate the impact of diet-induced hepatic steatosis in a murine model of IRI. Using a diet of high trans-fat, fructose, and cholesterol (HTF-C) and a diet high in saturated fats, sucrose, and cholesterol (Western diet), we were able to establish models of mixed macrovesicular and microvesicular steatosis (HTF-C) and microvesicular steatosis (Western). We found that the presence of hepatic steatosis, whether it is predominantly macrovesicular or microvesicular, significantly worsens IRI as measured by plasma alanine aminotransferase levels and inflammatory cytokine concentration, and histological evaluation for necrosis. Additionally, we report on a novel finding in which hepatic IRI in the setting of steatosis results in the induction of the necroptosis factors, receptor interacting protein kinase (RIPK) 3, RIPK1, and mixed-lineage kinase domain-like. These data lay the groundwork for additional experimentation to test potential therapeutic approaches to limit IRI in steatotic livers by using a genetically tractable system. Liver Transplantation 24 908-921 2018 AASLD.

The weekend effect in liver transplantation

Background

The weekend effect describes a phenomenon whereby patients admitted to hospitals on weekends are at higher risk of complications compared to those admitted during weekdays. However, if a weekend effect exists in orthotopic liver transplantation (oLT).

Methods

We analyzed oLT between 2006 and 2016 and stratified patients into weekday (Monday to Friday) and weekend (Saturday, Sunday) groups. Primary outcome measures were one-year patient and graft survival.

Results

364 deceased donor livers were transplanted into 329 patients with 246 weekday (74.77%) and 83 weekend (25.23%) patients. Potential confounders (e.g. age, ischemia time, MELD score) were comparable. One-year patient and graft survival were similar. Frequencies of rejections, primary-non function or re-transplantation were not different. The day of transplantation was not associated with one-year patient and graft survival in multivariate analysis.

Conclusions

We provide the first data for the Eurotransplant region on oLT stratified for weekend and weekday procedures and our findings suggest there was no weekend effect on oLT. While we hypothesize that the absent weekend effect is due to standardized transplant procedures and specialized multidisciplinary transplant teams, our results are encouraging showing oLT is a safe and successful procedure, independent from the day of the week.

Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter

BACKGROUND

To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology.

METHODS

Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound systems. CAP was obtained with the FibroScan 502 Touch device (Echosens, Paris, France). Pearson's or Spearman's rank correlation coefficient were used to test the association between two study variables. Optimal cutoff of CAP for detecting steatosis was 249 dB/m. The diagnostic performance of dichotomized CAP, US, body mass indexes (BMI), fatty liver index (FLI) and hepatic steatosis index (HSI) was analyzed using the imperfect gold standard methodology.

RESULTS

Three hundred five pediatric patients were enrolled. The data of both US and CAP were available for 289 children. Steatosis was detected in 50/289 (17.3%) children by US and in 77/289 (26.6%) by CAP. A moderate to good correlation was detected between CAP and BMI (r = 0.53), FLI (r = 0.55) and HSI (r = 0.56). In obese children a moderate to good correlation between CAP and insulin levels (r = 0.54) and HOMA-IR (r = 0.54) was also found. Dichotomized CAP showed a performance of 0.70 (sensitivity, 0.72 [0.64-0.79]; specificity, 0.98 [0.97-0.98], which was better than that of US (performance, 0.37; sensitivity, 0.46 [0.42-0.50]; specificity, 0.91 [0.89-0.92]), BMI (performance, 0.22; sensitivity, 0.75 [0.73-0.77]; specificity, 0.57 [0.55-0.60]) and FLI or HSI.

CONCLUSIONS

For the evaluation of liver steatosis in children CAP performs better than US, which is the most widely used imaging technique for screening patients with a suspicion of liver steatosis. A cutoff value of CAP of 249 dB/m rules in liver steatosis with a very high specificity.

Donor BMI >30 Is Not a Contraindication for Live Liver Donation

The increased prevalence of obesity worldwide threatens the pool of living liver donors. Although the negative effects of graft steatosis on liver donation and transplantation are well known, the impact of obesity in the absence of hepatic steatosis on outcome of living donor liver transplantation (LDLT) is unknown. Consequently, we compared the outcome of LDLT using donors with BMI <30 versus donors with BMI ≥30. Between April 2000 and May 2014, 105 patients received a right-lobe liver graft from donors with BMI ≥30, whereas 364 recipients were transplanted with grafts from donors with BMI <30. Liver steatosis >10% was excluded in all donors with BMI >30 by imaging and liver biopsies. None of the donors had any other comorbidity. Donors with BMI <30 versus ≥30 had similar postoperative complication rates (Dindo-Clavien ≥3b: 2% vs. 3%; p = 0.71) and lengths of hospital stay (6 vs. 6 days; p = 0.13). Recipient graft function, assessed by posttransplant peak serum bilirubin and international normalized ratio was identical. Furthermore, no difference was observed in recipient complication rates (Dindo-Clavien ≥3b: 25% vs. 20%; p = 0.3) or lengths of hospital stay between groups. We concluded that donors with BMI ≥30, in the absence of graft steatosis, are not contraindicated for LDLT.

The clinical value of controlled attenuation parameter for the noninvasive assessment of liver steatosis

BACKGROUND & AIMS

Ultrasound is the imaging modality most widely utilized in the general population for diagnostic purposes. Controlled attenuation parameter is a novel noninvasive method for assessing steatosis. Our aim was to investigate whether the clinical value of controlled attenuation parameter in patients referred for abdominal ultrasound examinations is affected by liver fibrosis.

METHODS

Consecutive patients referred for abdominal ultrasound examinations were enrolled. Controlled attenuation parameter and liver stiffness were assessed with the FibroScan (Echosens, France). Liver fibrosis was staged according to published cutoffs of liver stiffness measurements. Pearson's or Spearman's rank correlation coefficient was used to test the association between two study variables. Optimal cutoff of controlled attenuation parameter for diagnosing liver steatosis (S≥2) was 256 dB/m. The diagnostic performance and accuracy of dichotomized controlled attenuation parameter, ultrasound and body mass index were analysed using the imperfect gold standard methodology.

RESULTS

A total of 726 subjects (464 males and 262 females) were studied. Five hundred and eight-nine (81.1%) patients were affected by chronic viral hepatitis. Correlation of controlled attenuation parameter with ultrasound score was 0.48 and 0.57 in patients with and without chronic viral hepatitis respectively. In patients with chronic viral hepatitis, ultrasound, dichotomized controlled attenuation parameter and body mass index showed performance of 58.2%, 82.3% and 46.7%, respectively, whereas in patients without chronic viral hepatitis, the performance was 86.4%, 68.6% and 48.6% respectively.

CONCLUSIONS

In patients with chronic viral hepatitis and advanced liver fibrosis, controlled attenuation parameter performs better than ultrasound for assessing liver steatosis, whereas in patients without viral hepatitis and with nonsignificant liver disease ultrasound shows the best performance.

Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46; p = 0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65; p < 0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93; p = 0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95; p = 0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00; p = 0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match.

Size mismatch in liver transplantation

Size mismatch is an unique and inevitable but critical issue in live donor liver transplantation. Unmatched metabolic demand of recipient as well as physiologic mismatch aggravates the damage to liver graft, inevitably leading to graft failure on recipient. Also, an excessive resection of liver graft for better recipient outcome in live donor liver transplant may jeopardize the healthy donor well-being and even put donor life in danger. There is a fine balance between resected graft volume required to meet the recipient's metabolic demand and residual graft volume required for donor safety. The obvious clinical necessity of finding that balance has prompted a clinical need and promoted the improvement of knowledge and development of management strategies for size-mismatched transplants. The development of the size-matching methodology has significantly improved graft outcome and recipient survival in live donor liver transplants. On the other hand, the effect of size mismatch in cadaveric transplants has never been observed as being so pronounced. The importance of matching of the donor recipient size has been unrecognized in cadaveric liver transplant. In this review, we attempt to summarize the current most updated knowledge on the subject, particularly addressing the definition and complications of size-mismatched cadaveric liver transplant, as well as management strategies.

Macrovesicular steatosis in living related liver donors: correlation of biopsy findings with CT liver attenuation index and body mass index

BACKGROUND

Hepatic steatosis threatens post-transplant graft survival; therefore, pre-operative quantification of steatosis is crucial. Gold standard for evaluation is donor liver biopsy but it is invasive. An alternative non-invasive method is a calculation of CT liver attenuation index. BMI can be an independent factor predicting grade of steatosis but it is necessary to re-define appropriate BMI cut-off points that are specific for Asians.

OBJECTIVE

To retrospectively analyze CT LAI and BMI for quantitative assessment of macrovesicular steatosis in living related liver donors, using histological analysis as gold standard.

MATERIALS AND METHODS

A radiologist blinded to histological grading calculated mean CT hepatic attenuation in 48 potential living related liver donors.

RESULTS

CT-derived LAI correctly predicted steatosis in all except 1 patient. Parametric analysis for CT LAI and BMI showed overall weak positive correlation. No significant association was found between BMI and biopsy findings.

CONCLUSION

Liver biopsy remains a gold standard for evaluation of steatosis. CT LAI of ≤0 correlates well with significant hepatic steatosis and biopsy may be avoided in such cases. Biopsy may be reserved for patients with CT LAI between 1 and 5. BMI alone is not a good predictor of hepatic steatosis in our study population.

Recipient Hyperbilirubinemia May Reduce Ischemia-Reperfusion Injury but Fails to Improve Outcome in Clinical Liver Transplantation

Background. Exogenous bilirubin may reduce experimental ischemia-reperfusion injury (IRI) due to its antioxidant properties. We studied if early graft exposure to high bilirubin levels in the recipient affects the early IRI and outcomes after liver transplantation (LTx). Methods. In 427 LTx patients, the AUROC curve based on bilirubin and AST at day 1 identified a cutoff of 2.04 mg/dL for the recipient pretransplant bilirubin. Recipients were grouped as having low (group L, n = 152) or high (group H, n = 275) bilirubin. Both groups had similar donor-related variables (age, preservation time, donor BMI > 28, and donor risk index (DRI)). Results. Alanine (ALT) and aspartate (AST) aminotransferase levels were higher in group L at day 1; ALT levels remained higher at day 2 in group L. LTx from high risk donors (DRI > 2) revealed a trend towards lower transaminases during the first two days after transplantation in group H. One month and 1-year patient survival were similar in groups L and H. High preoperative bilirubin did not affect the risk for early graft dysfunction (EGD), death, or graft loss during the first year after transplantation nor the incidence of acute rejection. LTx using donors with DRI > 2 resulted in similar rates of EGD in both groups. Conclusion. Increased bilirubin appears to reduce the early IRI after LTx yet this improvement was insufficient to improve the clinical outcome.

Postoperative coagulopathy after live related donor hepatectomy: Incidence, predictors and implications for safety of thoracic epidural catheter

Background:

Coagulopathy after living donor hepatectomy (LDH) may endanger donor safety during removal of thoracic epidural catheter (TEC). The present study was conducted to evaluate the extent and duration of immediate postoperative coagulopathy after LDH.

Materials and Methods:

A retrospective analysis of perioperative record of LDH over three years was conducted after IRB approval. Variables such as age, gender, BMI, ASA classification, liver volume on CT scan, preoperative and postoperative INR, platelet count (PC) and ALT of each donor for five days was noted. In addition, duration of surgery, remnant as percentage total liver volume (Remnant%), blood loss, day of peak in PC and INR were also noted. Coagulopathy was defined as being present if INR exceeded 1.5 or platelet count fell below 1 × 10⁵/mm³ on any day. Data was analyzed using SPSS 20 for Windows. Between group comparison was made using the Student ‘t’ test for continuous variables and chi square test for categorical variables. Univariate analysis was done. Multiple logistic regression analysis was used to find independent factor associated with coagulopathy.

Results:

Eighty four (84) donors had coagulopathy on second day (mean INR 1.9 ± 0.42). Low BMI, % of remnant liver and duration of surgery were independent predictors of coagulopathy. Right lobe hepatectomy had more coagulopathy than left lobe and low BMI was the only independent predictor. There was no correlation of coagulopathy with age, gender, blood loss, presence of epidural catheter, postoperative ALT or duration of hospital stay. High INR was the main contributor for coagulopathy.

Conclusions:

Coagulopathy is seen after donor hepatectomy. We recommend removal of the epidural catheter after the fifth postoperative day when INR falls below 1.5.

Brain death and marginal grafts in liver transplantation

It is well known that most organs for transplantation are currently procured from brain-dead donors; however, the presence of brain death is an important risk factor in liver transplantation. In addition, one of the mechanisms to avoid the shortage of liver grafts for transplant is the use of marginal livers, which may show higher risk of primary non-function or initial poor function. To our knowledge, very few reviews have focused in the field of liver transplantation using brain-dead donors; moreover, reviews that focused on both brain death and marginal grafts in liver transplantation, both being key risk factors in clinical practice, have not been published elsewhere. The present review aims to describe the recent findings and the state-of-the-art knowledge regarding the pathophysiological changes occurring during brain death, their effects on marginal liver grafts and summarize the more controversial topics of this pathology. We also review the therapeutic strategies designed to date to reduce the detrimental effects of brain death in both marginal and optimal livers, attempting to explain why such strategies have not solved the clinical problem of liver transplantation.

Major complications of adult right lobe living liver donors

BACKGROUND

The right lobe of the liver is generally preferred for living donor liver transplantation in adult patients with end-stage liver disease. It is important to know the preoperative factors relating to the major postoperative complications. We therefore evaluated the possible risk factors for predicting postoperative complications in right lobe liver donors.

METHODS

Data from 378 donors who had undergone right lobe hepatectomy at our center were evaluated retrospectively. The factors we evaluated included donor age, gender, body mass index (BMI), remnant liver volume, operation time, history of previous abdominal surgery, inclusion of the middle hepatic vein and variations in the portal and bile systems.

RESULTS

Of the 378 donors, 219 were male and 159 female. None of the donors died, but 124 (32.8%) donors experienced complications including major complications (Clavien scores III and IV) in 27 (7.1%). Univariate analysis showed that complications were significantly associated with male gender and higher BMI (P<0.05), but not with donor age, remnant liver volume, operation time, graft with middle hepatic vein, variations in the portal and bile systems and previous abdominal surgery (P<0.05). Multivariate logistic regression analysis showed that major complications were significantly associated with male gender (P=0.005) and higher BMI (P=0.029). Moreover, the Chi-square test showed that there were significant relationships between major complications and male gender (P=0.010, X2=6.614, df=1) and BMI >25 kg/m2 (P=0.031, X2=8.562, df=1). Of the 96 male donors with BMI >25 kg/m2, 14 (14.6%) with major complications had significantly smaller mean remnant liver volume than those (82, 85.4%) without major complications (32.50%+/-4.45% vs 34.63%+/-3.11%, P=0.029).

CONCLUSION

Male donors with BMI >25 kg/m2 and a remnant liver volume ≤32.50% had a significantly increased risk for major complications.

Segment 4 and the left lateral segment regeneration pattern after resection of the middle hepatic vein in a living donor right hepatectomy

BACKGROUND

Inclusion of the middle hepatic vein (MHV) with a right hepatectomy (RH) in live donor liver transplantation improves venous drainage of the anterior sector of the graft. Its long-term effects on donor left liver (LL) regeneration are not well described.

METHODS

Donors who underwent RH with MHV (MHV+, n = 12) were compared with donors who underwent RH with preservation of the MHV (MHV-, n = 24). Peri-operative complications and volume of the entire liver and individual segments were evaluated at 1 year post-donation.

RESULTS

There was a trend towards a higher complication rate in the MHV+ group (41% versus 25%), without reaching statistical significance (P = 0.3). Males, high body mass index (BMI) and a smaller residual liver volume (RLV) were predictors for greater LL regeneration. MHV+ donors had impaired regeneration of segment 4 (S4) at 1 year, and compensatory greater left lateral segment regeneration. The absence of venous drainage of S4 (V4) to left hepatic vein (LHV) was a predictor of impaired S4 regeneration.

CONCLUSIONS

Regeneration of S4 is impaired in MHV+ donors. Caution should be taken when considering MHV removal on donors with dominant S4, especially on those with potential increased demand for liver regeneration, such as males, higher BMI and a smaller RLV.

Data from a randomized and controlled trial of LCarnitine prescription for the treatment for Non- Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) consists of a range of complication. The disease describes clinical , para clinical and pathological conditions from simple steatosis in non-alcoholic steato hepatitis (NASH) to fibrosis, cirrhosis and hepato cellular carcinoma. Therefore, it is of interest to evaluate the grade of fatty liver and Liver Function Test in NAFLD patients. We collected samples and data from 80 patients referred to gastrointestinal clinic of Emam Reza hospital with sonography diagnosed NAFLD and were evaluated in two groups in a randomized clinical trial. The effects of L-Carnitine (500 mg) prescription twice a day on liver enzymes and echogenicity changes in case group was documented and compared with the control group. The mean age of the patients was 40.7±8 in the age range of 25 to 62 years old with 66 (82.5%) male and 14 (17.5%) female patients. Data show that fatty liver changes were not significantly different in the two groups (P=0.23). It is observed that the ALT was the only enzyme with significant changes (P=0.01) after a 24-week interval. It is also noted that the difference in fatty liver sonographic grading was also significant in the two groups (P=0.0001). Thus, proper therapeutic protocols can be adopted beside diet and weight loss to control the disease trend in consideration to the significant changes observed both in enzymatic levels and sonographic grading between the two groups of patients with NAFLD.

Intraoperative "no go" donor hepatectomy in living donor liver transplantation

BACKGROUND AND OBJECTIVE

Although there are many reports on donor safety, there are few concerning aborted donations. We sought to analyze the "no go" donor hepatectomies in our liver transplantation center over 10 years' experience.

METHODS

Among 290 living donors brought to the operating room for liver graft harvest from March 2002 to April 2012, we examined the reasons to abandon the procedure, comparing their data with those of successful donors.

RESULTS

The donor operation was aborted in 5 cases various for reasons. The main reason for the abandonment of the operation process was poor liver quality: in single cases there was: poor liver quality due to a massive cirrhotic nodule observed by laparoscopy; serious steatosis of the liver, indicated by an intraoperative biopsy; and an unsuitable biliary anatomy, including 4 branches with 2 small ones. In another case, a biliary duct variation in the intraoperative cholangiogram showed a narrow crotch of the left and right ducts. In the 5th case, the donor would have been left with only a small remaining left lobe (<30%) if the right lobe had been harvested. All 5 donors proceeded to accept a right lobe hepatectomy. Comparison with the 285 successful donors showed no significant differences in preoperative demographic data. All 5 donors recovered without complication and were in good condition over long-term follow-up.

CONCLUSIONS

A low rate of "no go" donor hepatectomy can be achieved. There was no short- or long-term harm to the living donor owing to abandonment of the procedure.

Clinical implications of preoperative and intraoperative liver biopsies for evaluating donor steatosis in living related liver transplantation

The role of liver biopsy in selecting optimal donors is an area of continuing controversy in living donor liver transplantation (LDLT). Our aim was to assess the potential implications of preoperative and intraoperative biopsies for evaluating donor liver fat content. Three thousand eight hundred fifty-nine consecutive subjects underwent predonation needle biopsy of the right lobe, and 1766 of these subjects actually donated their livers for LDLT and underwent intraoperative wedge biopsies of paired right and left lobes. The preoperative workup protocol also included abdominal ultrasonography (USG) and computed tomography (CT). Intersample agreement on steatosis grades (<5%, 5% to <15%, 15% to <30%, and ≥30%) was calculated, and clinicometabolic factors related to sampling variability were evaluated. For detecting ≥30% steatosis in the 3859 potential donors, USG and CT had sensitivities of 84.9% and 57.3%, specificities of 76.3% and 92.7%, positive predictive values of 29.6% and 48.0%, and negative predictive values of 97.7% and 94.8%, respectively. Analyses of the 1766 actual donors showed that with respect to the total steatosis grades of intraoperative right and left biopsies versus preoperative biopsy, 36.7% and 36.0% of the pairs, respectively, differed from the weighted κ values of 0.44 and 0.40. Similar agreement levels existed for macrovesicular and microvesicular steatosis subtypes. The per-subject agreement rate for the total steatosis grade between intraoperative right and left biopsies was 83.6%. According to a multivariate analysis, independent factors affecting the variability of the total steatosis results from preoperative and intraoperative biopsies (major features) were higher systolic blood pressure, body mass index, and alanine aminotransferase values and lower high-density lipoprotein cholesterol values. In conclusion, imaging may be insufficiently sensitive for evaluating donor hepatic steatosis. Preoperative and selective intraoperative liver biopsies are mandatory for assessing donor steatosis in LDLT unless preoperative imaging demonstrates no fat.

Overweight in liver transplant recipients

This review aims to describe the incidence and prevalence of overweight and obesity after liver transplantation and the consequences associated with it. Literature review consultation was conducted in Medline / PubMed, SciELO, EMBASE and LILACS, with the combination of the following keywords: liver transplantation, overweight, obesity, weight gain. Overweight is incident on more than 60% of patients undergoing liver transplantation and obesity rates exceed 20% in the first year after surgery, during which occurs the largest relative weight gain. Studies have shown that between 60% and 70% of patients undergoing liver transplantation are overweight after the third year, 90% with abdominal obesity. Associated factors are, among others, advanced age, family history of overweight and excess weight prior to liver disease. The contribution of immunosuppressive medication remains controversial. Some of the consequences of overweight are liver steatosis, steatohepatitis, diabetes mellitus, hypertension, dyslipidemia, cardiovascular disease and death.

Changing pattern of donor selection criteria in deceased donor liver transplant: a review of literature

During the last couple of decades, with standardization and progress in surgical techniques, immunosuppression and post liver transplantation patient care, the outcome of liver transplantation has been optimized. However, the principal limitation of transplantation remains access to an allograft. The number of patients who could derive benefit from liver transplantation markedly exceeds the number of available deceased donors. The large gap between the growing list of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donor pool and identify new avenues. This article reviews the changing pattern of donor for liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis), donation after cardiac death, use of partial grafts (split liver grafts) and other suboptimal donors (hypernatremia, infections, hypotension and inotropic support).

Safe use of highly steatotic livers by utilizing a donor/recipient clinical algorithm

The aim of this study was to assess the long-term safety and clinical outcomes associated with the utilization of highly steatotic donor livers utilizing a specific donor/recipient matching algorithm. This was a prospective, observational, single-center, 10-yr follow-up study. Highly steatotic livers were utilized according to a donor/recipient algorithm that guided the surgeon to use highly steatotic donor organs judiciously in low-risk recipients. This study initially compared fat assessment based on frozen-section Ehrlich's hematoxylin and eosin (H&E) to reperfusion biopsy fat assessment and demonstrated that H&E is an insensitive analysis to determine degree of steatosis. Patients were divided into three groups based on donor steatosis (group 1: <30% steatosis, group 2: 30-60% steatosis, group 3: >60% steatosis), and clinical outcomes were assessed. One hundred and sixteen patients were included in the analysis. Patients that received severely steatotic livers (>60% fat) showed increased reperfusion liver injury and delayed return of liver function in the early postoperative period, demonstrated by biochemical markers. However, there were no differences in primary non-function, postoperative complications, length of stay, and patient and graft survival. Using rigorous donor/recipient matching through a detailed algorithm, these data demonstrate that normal liver allograft outcomes are not superior to those in highly steatotic grafts.

Genetic variation at NCAN locus is associated with inflammation and fibrosis in non-alcoholic fatty liver disease in morbid obesity

OBJECTIVE

Obesity-associated non-alcoholic fatty liver disease (NAFLD) may cause liver dysfunction and failure. In a previously reported genome-wide association meta-analysis, single nucleotide polymorphisms (SNPs) near PNPLA3, NCAN, GCKR, LYPLAL1 and PPP1R3B were associated with NAFLD and with distinctive serum lipid profiles. The present study examined the relevance of these variants to NAFLD in extreme obesity.

METHODS

In 1,092 bariatric surgery patients, the candidate SNPs were genotyped and association analyses with liver histology and serum lipids were performed.

RESULTS

We replicated the association of hepatosteatosis with PNPLA3 rs738409[G] and with NCAN rs2228603[T]. We also replicated the association of rs2228603[T] with hepatic inflammation and fibrosis. rs2228603[T] was associated with lower serum low-density lipoprotein, total cholesterol and triglycerides. After stratification by the presence or absence of NAFLD, these associations were present predominantly in the subgroup with NAFLD.

CONCLUSION

NCAN rs2228603[T] is a risk factor for liver inflammation and fibrosis, suggesting that this locus is responsible for progression from steatosis to steatohepatitis. In this bariatric cohort, rs2228603[T] was associated with low serum lipids only in patients with NAFLD. This supports a NAFLD model in which the liver may sequester triglycerides as a result of either increased triglyceride uptake and/or decreased lipolysis.

The aggressive phenotype revisited: utilization of higher-risk liver allografts

Organ shortage has led to increased utilization of higher risk liver allografts. In kidneys, aggressive center-level use of one type of higher risk graft clustered with aggressive use of other types. In this study, we explored center-level behavior in liver utilization. We aggregated national liver transplant recipient data between 2005 and 2009 to the center-level, assigning each center an aggressiveness score based on relative utilization of higher risk livers. Aggressive centers had significantly more patients reaching high MELDs (RR 2.19, 2.33 and 2.28 for number of patients reaching MELD>20, MELD>25 and MELD>30, p<0.001), a higher organ shortage ratio (RR 1.51, 1.60 and 1.51 for number of patients reaching MELD>20, MELD>25 and MELD>30 divided by number of organs recovered at the OPO, p<0.04), and were clustered within various geographic regions, particularly regions 2, 3 and 9. Median MELD at transplant was similar between aggressive and nonaggressive centers, but average annual transplant volume was significantly higher at aggressive centers (RR 2.27, 95% CI 1.47-3.51, p<0.001). In cluster analysis, there were no obvious phenotypic patterns among centers with intermediate levels of aggressiveness. In conclusion, highwaitlist disease severity, geographic differences in organ availability, and transplant volume are the main factors associated with the aggressive utilization of higher risk livers.

"Small-for-flow" syndrome: shifting the "size" paradigm

The "small-for-size" syndrome and "post-hepatectomy liver failure" refers to the development of liver failure (hyperbilirubinemia, coagulopathy, encephalopathy and refractory ascites) resulting from the reduction of liver mass beyond a certain threshold. This complication is associated with a high mortality and is a major concern in liver transplantation involving reduced liver grafts from deceased and living donors as well as in hepatic surgeries involving extended resections of liver mass. The limiting threshold for liver resection or transplantation is currently predicted based on the mass of the remnant liver (or donor graft) in relation to the body weight of the patient, with a ratio above 0.8 being considered safe. This approach, however, has proved inaccurate, because some patients develop the "small-for-size" syndrome despite complying with the "safe" threshold while other patients who surpass the threshold do not develop it. We hypothesize that the development of the "small-for-size" syndrome is not exclusively determined by the ratio of the mass of the liver remnant (or graft) to the body weight, but it is instead strictly determined by the hemodynamic parameters of the hepatic circulation. This hypothesis is based in recent clinical and experimental reports showing that relative portal hyperperfusion is a critical factor in the development of the "small-for-size" syndrome and that maneuvers that manipulate the hepatic vascular inflow are able to prevent the development of the syndrome despite liver-to-body weight ratios well below the "limiting" threshold. Measurements of hepatic blood flow and pressure, however, are not routinely performed in hepatic surgeries. Focusing on the "flow" rather than in the "size" may improve our understanding of the pathophysiology of the "small-for-size" syndrome and "post-hepatectomy liver failure" and it would have important implications for the clinical management of patients at risk. First, hepatic hemodynamic parameters would have to be measured in hepatic surgeries. Second, these parameters (in addition to liver mass) would be the principal basis for deciding the "safe" threshold of viable liver parenchyma. Third, the hepatic hemodynamic parameters are amenable to manipulation and, consequently, the "safe" threshold may also be manipulated. Shifting the paradigm from "small-for-size" to "small-for-flow" syndrome would thus represent a major step for optimizing the use of donor livers, for expanding the indications of hepatic surgery, and for increasing the safety of these procedures.

Suramin decreases injury and improves regeneration of ethanol-induced steatotic partial liver grafts

Steatotic grafts are excluded for use in partial liver transplantation (LT) because of the increased risk of primary nonfunction. This study investigated the effects of suramin, a polysulfonated naphthylurea, on the outcome of steatotic partial LT. Rat livers were harvested after acute ethanol treatment (6 g/kg, intragastric administration), reduced in size to ≈ 1/3, and transplanted. Serum alanine aminotransferase (ALT) and total bilirubin levels as well as hepatic necrosis and apoptosis were significantly higher after transplantation of fatty partial grafts (FPG) than lean partial grafts (LPG). Suramin (5 mg/kg, i.p.) decreased ALT by ≈ 60%, hyperbilirubinemia by 75%, necrosis by 83%, and apoptosis by 70% after FPG transplantation. Hepatic cellular 5-bromo-2'-deoxyuridine (BrdU) incorporation increased to 28% in LPG but was only 2% in FPG at 48 hours, and the mitotic index increased to 7% in LPG but was only 0.2% in FPG, indicating suppressed regeneration in FPG. Suramin increased BrdU incorporation and the mitotic index to 43% and 9%, respectively, in FPG. All FPG recipients died within 5 days. Suramin recovered survival of FPG to 62%. Tumor necrosis factor-α (TNF-α) mRNA was 2.2-fold higher in FPG than in LPG and was associated with activation of caspase-8 and caspase-3 in FPG. Suramin decreased TNF-α and caspase activation in FPG. Transforming growth factor-β (TGF-β), phospho-Smad2/3 and p21Cip1 were significantly higher in FPG than in LPG and suramin blocked TGF-β formation and its down-stream signaling pathway. Taken together, suramin improves the outcome of FPG transplantation, most likely by inhibition of TNF-α and TGF-β formation.

Effects of donor steatosis on liver biochemistry and significance of body mass index in predicting steatosis

BACKGROUND

Hepatic steatosis is a major concern in living donor liver transplantation. Factors affecting hepatic functional status after a donor right hepatectomy (with the middle hepatic vein included in the graft) with a focus on changes owing to steatosis were retrospectively studied.

METHODS

Donors (n = 325) were categorized into three groups: G0 (no steatosis, n = 178), G1 (< = 10% steatosis, n = 128) and G2 (>10% steatosis, n = 19). Donors with >20% steatosis were excluded. Changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin levels and prothrombin time (PT) were assessed. Factors predicting steatosis were also assessed. A liver biopsy was performed on selected donors.

RESULTS

The ALT level rose until day 3 in G1 and day 6 in G2 (P < 0.05). The AST level rose until day 7 in G2 (P < 0.05) but stayed unchanged in G1. The bilirubin level was higher only on day 1 in G2 (P < 0.05). By day 30, no significant difference between any groups was noted. Receiver-operating characteristic (ROC) area under the curve for body mass index (BMI) on predicting steatosis was 0.75 [confidence interval (CI) = 69-80]. Among donors with a BMI > 23.5 kg/m(2), 75% had steatosis. Five donors had >20% steatosis and were not assessed.

CONCLUSION

Using a liver with up to 20% steatosis in right liver donation, even if the middle hepatic vein is included in the graft, is safe. For Asian donors, a BMI > 23.5 kg/m(2) is a guide in deciding whether to perform a liver biopsy for steatosis.

Safety and feasibility of diet-treated donors with steatotic livers at the initial consultation for living-donor liver transplantation

BACKGROUND

The purpose of this study was to evaluate both safety of diet-treated donors and the feasibility of their use for living-donor liver transplantation (LDLT).

METHODS

A total of 128 living donors were enrolled in this study between April 2003 and March 2010. Of them, 41 were diagnosed with hepatic steatosis at the initial consultation. Donor selection was based on the findings of liver biopsy accompanied with normalization of liver function tests after diet treatment consisting of an 800 to 1400 kcal/day diet and a 100 to 400 kcal/day exercise without drug treatment, targeting body mass index of 22 kg/m².

RESULTS

Body mass index of diet-treated donors was significantly reduced with diet from 23.3 ± 0.6 to 21.9 ± 0.4 kg/m² (P<0.0001). Liver function tests associated with fatty liver, including alanine aminotransferase, gamma-glutamyl transpeptidase, and total cholesterol levels, also improved with diet (P=0.0128, 0.0016, and 0.0004, respectively). The liver biopsy results of most of these donors showed stage 0/1 fibrosis and minimal/mild steatosis after the diet therapy. Surgical outcomes, including postoperative liver function tests, perioperative complications, and liver regeneration rates, did not significantly differ between nondiet-treated and diet-treated donors. Surgical outcomes and the overall survival did not significantly differ between recipients of grafts from nondiet-treated and diet-treated donors.

CONCLUSION

The use of diet-treated donors for living-donor liver transplantation is feasible with respect to donor safety and the outcome of the recipient when strict selection criteria are used.

Role of inducible nitric oxide synthase in mitochondrial depolarization and graft injury after transplantation of fatty livers

This study investigated the role of inducible nitric oxide synthase (iNOS) in failure of ethanol-induced fatty liver grafts. Rat livers were explanted 20 h after gavaging with ethanol (5 g/kg) and storing in UW solution for 24h before implantation. Hepatic oil red O staining-positive areas increased from ∼2 to ∼33% after ethanol treatment, indicating steatosis. iNOS expression increased ∼8-fold after transplantation of lean grafts (LG) and 25-fold in fatty grafts (FG). Alanine aminotransferase release, total bilirubin, hepatic necrosis, TUNEL-positive cells, and cleaved caspase-3 were higher in FG than LG. A specific iNOS inhibitor 1400W (5 μM in the cold-storage solution) blunted these alterations by >42% and increased survival of fatty grafts from 25 to 88%. Serum nitrite/nitrate and hepatic nitrotyrosine adducts increased to a greater extent after transplantation of FG than LG, indicating reactive nitrogen species (RNS) overproduction. Phospho-c-Jun and phospho-c-Jun N-terminal kinase-1/2 (JNK1/2) were higher in FG than in LG, indicating more JNK activation in fatty grafts. RNS formation and JNK activation were blunted by 1400W. Mitochondrial polarization and cell death were visualized by intravital multiphoton microscopy of rhodamine 123 and propidium iodide, respectively. After implantation, viable cells with depolarized mitochondria were 3-fold higher in FG than in LG and 1400W decreased mitochondrial depolarization in FG to the levels of LG. Taken together, iNOS is upregulated after transplantation of FG, leading to excessive RNS formation, JNK activation, mitochondrial dysfunction, and severe graft injury. The iNOS inhibitor 1400W could be an effective therapy for primary nonfunction of fatty liver grafts.

Visceral abdominal and subfascial femoral adipose tissue have opposite associations with liver fat in overweight and obese premenopausal caucasian women

Abdominal obesity has been associated with liver fat storage. However, the relationships between other body composition depots and metabolic syndrome features with hepatic fat are still unclear. We examined abdominal and thigh adipose tissue (AT) compartments associations with liver fat in 140 overweight and obese premenopausal Caucasian women. Blood lipids and, proinflammatory and atherothrombotic markers associations with hepatic fat were also analyzed. A larger visceral AT (VAT) was related with liver fat (P < 0.05). Contrarily, thigh subfascial AT was inversely related to liver fat (P < 0.05). Increased fasting insulin, triglycerides, PAI-1 concentrations, and a higher total-cholesterol/HDL-cholesterol ratio were also associated with hepatic fat, even after adjustment for VAT (P < 0.05). Thigh subfascial adiposity was inversely associated with liver fat, suggesting a potential preventive role against ectopic fat storage in overweight and obese women. These results reinforce the contribution of an abdominal obesity phenotype associated with a diabetogenic and atherothrombotic profile to liver lipotoxicity.

Body surface area index predicts outcome in orthotopic liver transplantation

BACKGROUND/PURPOSE

In living donor liver transplantation (LDLT), matching of liver volume between donor and recipient is critical to the success of the procedure; mismatch can result in 'small- or large-for-size syndrome'. In orthotopic liver transplantation (OLT), matching criteria are less stringent and non-uniform. We sought to determine whether a new parameter, the ratio of donor to recipient body surface area (BSAi), is predictive of size mismatch and/or post-transplant morbidity or mortality.

METHODS

We reviewed data on 1228 OLT recipients and stratified this data according to three categories: small-for-size (BSAi <0.6), control (BSAi = 0.6-1.4), and large-for-size (BSAi >1.4) donors.

RESULTS

We found that: (1) matching of grafts at the upper and lower extremes of BSAi had significantly reduced graft survival; (2) matches with lower BSAi sustained a less severe form of intraoperative post-reperfusion syndrome, and the incidence of hepatic artery thrombosis was high postoperatively in these grafts; (3) BSAi and donor age correlated well with the severity of intraoperative post-reperfusion hypotension; and (4) small-for-size (BSAi <0.6) and large-for-size (BSAi >1.4) grafts, as well as preoperative total bilirubin, were significant risk factors for decreased graft survival.

CONCLUSION

We conclude that the BSAi can predict clinically significant size mismatch and adverse outcomes in cadaveric whole OLT.

Factors associated with changes in coagulation profiles after living donor hepatectomy

BACKGROUND

Hepatic resection may be associated with postoperative coagulopathy. However, there is limited information about the predictors affecting coagulopathy after donor hepatectomy. We evaluated the contributors of maximal changes in prothrombin time (PT), activated thromboplastin time (aPTT), and platelet count in the development of postoperative coagulopathy.

METHODS

We retrospectively analyzed 864 living donors, all of whom received general anesthesia using desflurane, isoflurane, or sevoflurane. A coagulation derangement was defined as one or more of the following events postoperatively: peak PT >1.5 international normalized ratio (INR; highest quartile of PT), peak aPTT >46 seconds (highest quartile of aPTT), or nadir platelet count <100 × 10(9)/L. Factors were evaluated by univariate and multivariate logistic regression analysis to identify predictors of coagulopathy.

RESULTS

Mean postoperative peak PT, peak aPTT, and nadir platelet count were 1.4 ± 0.2 INR, 43.8 ± 23.7 seconds, and 155.9 ± 37.3 × 10(9)/L, respectively, with 39.4% of donors being at the risk for coagulation derangement. Multivariate logistic regression analysis revealed that predictors of such derangement included anesthesia duration, remnant liver volume, and body mass index (BMI). However, coagulation derangement was not independently associated with age, gender, volatile anesthetics, central venous pressure, fatty change in the liver, estimated blood loss, or intraoperative hypotensive episodes.

CONCLUSION

We found that long anesthesia duration, low BMI, and small remnant liver volume were predictors of coagulation derangement. These results provide a better understanding of risk factors affecting changes in coagulation profiles after living donor hepatectomy.

Standard formula for liver volume in Middle Eastern Arabic adults

OBJECTIVES

To determine a formula for estimating the standard liver volume (SLV) in Middle Eastern Arabic adults and to compare it with the 12 standard liver volume (SLV) formulas reported for eastern and western populations.

METHODS

Liver volume measured using computed tomography (CTLV) was determined in 351 Saudi Arabian adults older than 16 years without liver or body build abnormality. This measurement was correlated with body indices including age, sex, height, weight, body mass index, and body surface area to derive a new formula using multiple-step linear regression analysis. The CTLV was compared with the 12 SLV formulas using the t test, with error % as (SLV - CTLV)/CTLV × 100.

RESULTS

Body weight was the only significant factor that correlated with CTLV, that is, 12.26 × body weight (kg) + 555.65 (R(2) = .37; P = .000). Only the Vauthey formula (1267.28 × body surface area (m(2)) - 794.41) yielded an estimation of SLV that did not differ significantly from CTLV (P = .26), and had the least mean % error of +1% (underestimation by 15.7 mL) and the closest agreement, that is, 62.4% demonstrated less than ±16% error). Other formulas also yielded acceptable agreement with mean % error less than 12%, although the differences from actual measurements were statistically significant. The Chengdu and Chouker formulas were the exceptions, with more than 16% underestimation or overestimation.

CONCLUSIONS

Either the formulas derived in the present study and the Vauthey formula could be used to estimate SLV in Middle East Arabic adults. However, the moderate coefficient of determination (R(2) = .37) suggested wide interindividual variation. Caution must be exercised when using these formulas in preoperative planning.

The impact of nutrition on cirrhotic patients awaiting liver transplantation

PURPOSE OF REVIEW

To review the most recent aspects of nutrition therapy of cirrhotic patients on the waiting list for liver transplantation.

RECENT FINDINGS

Undernutrition has been widely reported among these patients, despite the lack of consensus on the best nutritional assessment tools in this population. Nutrition therapy has been marked by controversy. Nonetheless, recent findings have pointed out to the important role of the nutrition status and of some specific nutrients on the outcome of these patients.

SUMMARY

We report the latest findings on nutrition care of patients with end-stage liver disease on the waiting list for liver transplantation such as the impact of the nutritional status on outcome, probiotic and branched-chain amino acid supplementation, as well as the use of immunomodulating formula. Another important strategy that has been shown to improve these patients' nutritional care is the offering of nocturnal meals and micronutrient supplementation.

The diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis compared with liver biopsy: a meta-analysis

Objective

To meta-analyse the diagnostic accuracy of US, CT, MRI and ¹H-MRS for the evaluation of hepatic steatosis.

Methods

From a comprehensive literature search in MEDLINE, EMBASE, CINAHL and Cochrane (up to November 2009), articles were selected that investigated the diagnostic performance imaging techniques for evaluating hepatic steatosis with histopathology as the reference standard. Cut-off values for the presence of steatosis on liver biopsy were subdivided into four groups: (1) >0, >2 and >5% steatosis; (2) >10, >15 and >20%; (3) >25, >30 and >33%; (4) >50, >60 and >66%. Per group, summary estimates for sensitivity and specificity were calculated. The natural-logarithm of the diagnostic odds ratio (lnDOR) was used as a single indicator of test performance.

Results

46 articles were included. Mean sensitivity estimates for subgroups were 73.3–90.5% (US), 46.1–72.0% (CT), 82.0–97.4% (MRI) and 72.7–88.5% (¹H-MRS). Mean specificity ranges were 69.6–85.2% (US), 88.1–94.6% (CT), 76.1–95.3% (MRI) and 92.0–95.7% (¹H-MRS). Overall performance (lnDOR) of MRI and ¹H-MRS was better than that for US and CT for all subgroups, with significant differences in groups 1 and 2.

Conclusion

MRI and ¹H-MRS can be considered techniques of choice for accurate evaluation of hepatic steatosis.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-010-1905-5) contains supplementary material, which is available to authorized users.

Visceral adiposity and insulin resistance are independent predictors of the presence of non-cirrhotic NAFLD-related portal hypertension

INTRODUCTION

We previously demonstrated in an animal model that steatosis, in the absence of fibrosis, induces a significant rise in portal pressure, indicating substantial changes in liver hemodynamics. As assessment of portal pressure is an invasive procedure, non-invasive parameters are needed to identify patients at risk.

AIMS

To study the portal pressure in nonalcoholic fatty liver disease patients and to identify factors that are possibly related to steatosis-induced changes in liver hemodynamics.

MATERIALS AND METHODS

Patients presenting with a problem of overweight or obesity, and in whom non-invasive investigations showed signs of liver involvement, were proposed for transjugular hepatic vein catheterization and liver biopsy. The biopsy was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network Scoring System.

RESULTS

A total of 50 consecutive patients were studied. Their mean age was 47.9 ± 1.8 years; 31 (62%) were female. Hepatic venous pressure gradient was normal in 36 (72%) and elevated in 14 (28%) patients. The degree of steatosis was the only histological parameter that differed significantly between the two groups (P=0.016), and was a predictor of the presence of portal hypertension (PHT) in regression analysis (P=0.010). Comparing normal versus portal hypertensive patients, waist circumference (117 ± 2 versus 128 ± 4 cm, P=0.005), waist-hip ratio (0.96 ± 0.06 versus 1.04 ± 0.03, P=0.003), visceral fat (229 ± 15 versus 292 ± 35 cm(2), P=0.022), fasting insulin (15.4 ± 1.7 versus 21.8 ± 2.4 μU ml(-1), P=0.032), fasting c-peptide (1.22 ± 0.06 versus 1.49 ± 0.09 nmol l(-1), P=0.035) and homeostasis model assessment-insulin resistance (HOMA IR) (3.28 ± 0.29 versus 4.81 ± 0.57, P=0.019) were significantly higher. Age, gender, liver enzymes, ferritin and high-sensitive C-reactive protein were not significantly different. In regression analysis, waist circumference (P=0.008) and HOMA IR (P=0.043) were independent predictors of PHT.

CONCLUSIONS

Estimates of both visceral adiposity and IR are predictors for the presence of PHT, related to the degree of steatosis, and may help in identifying patients who are at risk of developing steatosis-related complications.

Recovery of liver function after the cessation of preoperative chemotherapy for colorectal liver metastasis

BACKGROUND

Preoperative chemotherapy containing oxaliplatin (FOLFOX) or irinotecan (FOLFIRI) causes histological liver injury and increases postoperative morbidity and mortality in patients with colorectal liver metastasis (CRLM). However, information on the aggravation of liver function and its reversibility is scarce.

METHODS

A total of 55 patients who underwent a hepatectomy after receiving FOLFOX and/or FOLFIRI were included in the present study. Indocyanine green tests were repeatedly performed before hepatectomy for monitoring the change of hepatic functional reserve.

RESULTS

A significant decrement in the ICG R15 value was observed at 2-4 weeks (12.9%, P = .04), 4-8 weeks (11.4%, P = .01), and 8 or more weeks (11.1%, P = .006) after the last chemotherapy, compared with results documented within 2 weeks (16.8%). However, no significant change was observed among the values obtained at 2-4 weeks, 4-8 weeks, and 8 or more weeks. The individual ICG R15 values at the beginning and end of the cessation period also improved from 17.7% to 11.6% (P = .001). Histological liver injury was associated with larger amounts of operative blood loss but not with morbidity. Neither liver failure nor mortality occurred in the present series.

CONCLUSIONS

The hepatic functional reserve, represented by the ICG R15 value, improves during the period after chemotherapy cessation. The present study suggests that chemotherapy cessation for at least 2-4 weeks enables an improvement in the hepatic functional reserve, especially among patients with an abnormal ICG R15 value (> 10%) who have received 6 or more cycles of FOLFOX and/or FOLFIRI.

Two-staged surgery for metastatic liver tumor in morbidly obese individual-left hemihepatectomy following placement of laparoscopic adjustable gastric band

A 47-year-old male with a body mass index (BMI) 37.12 kg/m(2) was diagnosed with an ill-demarcated tumor within IVB segment of left lobe of the liver. Sixteen months earlier, he underwent laparoscopic gastric banding for morbid obesity (BMI 51 kg/m(2)). One year after bariatric procedure, he was diagnosed with rectal adenocarcinoma. Following abdominoperineal resection of rectum with total mesorectal excision and 2 months course of adjuvant FOLFOX chemotherapy, he was scheduled for liver resection. Left hemihepatectomy was performed with no major complications; wound discharge was successfully treated in outpatient clinic. Twelve months following surgery, he remains disease free with no evidence of local recurrence, metachronic primary tumor, or distant metastases. This is first to our knowledge report providing data on the outcome of left hemihepatectomy performed in postbariatric patient. The role of bariatric surgery and utilization of the time necessary for neoadjuvant chemotherapy to reduce the excessive body mass and the degree of liver steatosis is discussed.

Inhibition of inducible nitric oxide synthase prevents mitochondrial damage and improves survival of steatotic partial liver grafts

BACKGROUND

Steatotic liver grafts are excluded for partial liver transplantation because of increased risk of primary nonfunction. Mechanisms underlying the failure of fatty partial liver grafts (FPG) remain unknown. This study investigated whether inducible nitric oxide synthase (iNOS) plays a role in failure of FPG.

METHODS

Fatty livers were induced by feeding rats a high-fat high-fructose diet for 2 weeks. Hepatic triglyceride was approximately 9-fold higher in rats fed the high-fat high-fructose diet than those fed a low-fat low-fructose diet. Lean and fatty liver explants were reduced in size ex vivo to approximately one third, stored in the University of Wisconsin cold storage solution for 2 hr, and implanted.

RESULTS

Posttransplantational hepatic iNOS expression and reactive nitrogen species (RNS) formation (nitrite and nitrate levels and 3-nitrotyrosine adducts) increased more profoundly in FPG than in lean partial grafts (LPG). Serum alanine aminotransferase and bilirubin were 2- and 5.5-fold higher after transplantation of FPG than LPG. 5-Bromo-2'-deoxyuridine incorporation was 25% in LPG but only 5% in FPG, and graft weight increased by 64% in LPG while remaining unchanged in FPG. All rats that received FPG died, whereas all those receiving LPG survived. N-(1-naphtyl)ethylendiamine dihydrochloride (5 microM), a specific iNOS inhibitor, largely blunted the production of RNS, prevented the increase of alanine aminotransferase and bilirubin, restored liver regeneration, and improved survival of FPG. Mitochondrial cytochrome c oxidase-IV, ATP synthase-beta, and NADH dehydrogenase-3 decreased markedly in FPG, and these effects were blocked by N-(1-naphtyl)ethylendiamine dihydrochloride.

CONCLUSION

Thus, hepatic steatosis causes failure of partial liver grafts, most likely by increasing RNS that leads to mitochondrial damage and dysfunction.

The role of marginal donors in liver transplantation. The Hungarian experience

A májátültetések számát korlátozza a beültetésre alkalmas donorszervek mennyisége. A szervhiány megoldására az egyik lehetőség az úgynevezett marginális donorok (extended donor criteria) elfogadása a májátültetési programban. Célkitűzés: A magyar májátültetési program szervdonációs jellemzőinek vizsgálata, különös tekintettel a marginális donorokra. Módszer: Donor- és recipiensadatok retrospektív feldolgozása 2003. január és 2008. december között. A marginálisdonor-kritériumrendszert nemzetközi ajánlások alapján állítottuk fel. Eredmények: A vizsgált periódus alatt összesen 1078 donort jelentettek a klinikán. Nyolcszázharmincöt esetben (77,4%) alkalmatlannak ítélték a donormájat a transzplantációra, 243 esetben (22,6%) volt beültetésre alkalmas a donormáj. A beültetett májgraftok közül 40 (16%) származott marginális, 203 (84%) nem marginális donorból. Marginális májgraftok beültetése esetén nem volt különbség a beteg- és grafttúlélésben, a posztoperatív graftfunkciót jelző paraméterekben és az általános szövődmények gyakoriságában. A korai hepatitis C-rekurrencia gyakoribb volt marginális graft beültetése esetén. Következtetések: A májátültetésre váró betegek száma hazánkban is folyamatosan növekszik. Marginális májgraftok alkalmazása esetén a betegek morbiditása és mortalitása nem különbözik számottevően a standard donorokból származó májgraftok beültetése után tapasztalt eredményektől. Hepatitis C-vírus esetén nem javasolt marginális májgraft beültetése. A donorok felső életkori határának kiterjesztése megfontolandó.

Quantitative estimation of the degree of hepatic macrovesicular steatosis in a disease-free population: a single-center experience in mainland China

The aim of this study was to derive a simple equation to enable the extent of hepatic macrovesicular steatosis (HMS) to be predicted quantitatively from data obtained noninvasively and hence avoid unnecessary liver biopsies. One hundred sixty-seven potential living liver donors and 45 subjects suspected of having nonalcoholic fatty liver disease (NAFLD) underwent percutaneous liver biopsy to evaluate HMS quantitatively. Their hepatic unenhanced computed tomography (CT) attenuation, body mass index (BMI), and indices of serum lipids were reviewed. Logistic regression analysis was undertaken to screen for independent predictors of HMS. Linear regression analysis was then used to plot the relationship between the severity of histologically confirmed HMS and identified independent predictors of HMS. For potential donors with HMS of severity > or = 5% by histological assessment, the following equation was derived: HMS = 47.7 + 1.48BMI - 1.14CT (R2 = 0.74)The calculated HMS for potential donors with histologically confirmed HMS of severity < 5% seemed to be unreliable (R(2) = = 0.230, P < 0.3). In addition, in subjects suspected of having NAFLD, there was a close agreement between values for histologically confirmed HMS and calculated values for HMS derived from the equation (intraclass correlation coefficient = 0.88). Hepatic CT imaging in conjunction with other noninvasive clinical data may enable the extent of HMS to be accurately predicted with the equation derived from potential donors with appreciable degrees of histologically confirmed HMS.

Metabolic syndrome and its components after liver transplantation: incidence, prevalence, risk factors, and implications

Metabolic syndrome is defined as the mutual existence of obesity, impaired fasting glucose levels, insulin resistance, hypertension, and dyslipidemia. After liver transplantation, patients typically develop these disorders, and even though there has been minimal research focused on the chronic impact of this syndrome on post-liver transplant patients, studies point to an association with major vascular events and fibrosis. The aim of the current work is to review data on the incidence, prevalence, risk factors, and implications of metabolic syndrome and its components in patients who have undergone liver transplantation.

Noninvasive estimation of hepatic steatosis in living liver donors: usefulness of visceral fat area measurement

BACKGROUND

Hepatic steatosis in the donor liver is associated with an increased risk of complications after liver transplantation. Mandatory liver biopsy for all potential donors, however, remains controversial. To define clinico-pathological correlation, we reviewed our criteria for liver biopsy and examined the use of visceral fat area (VFA) estimation by computed tomography image.

METHODS

Our criteria for biopsy are as follows: an aspartate aminotransferase/alanine aminotransferase ratio of less than 1, a body mass index more than or equal to 25 kg/m2, and a suspected fatty liver on ultrasonography. Dietary intervention is indicated for overweight donor candidates and for those with more than 10% hepatic steatosis. Clinical data of consecutive 78 potential donors who underwent percutaneous liver biopsy (biopsy group) and 70 donors whose biopsy were omitted (control group) were reviewed.

RESULTS

Donors in biopsy group were male dominant with a median age of 35 (20-63) years. Hepatic steatosis more than or equal to 10% was seen in nine of 78 donors; older age (P=0.012), ultrasonographic findings (P=0.002), VFA (P=0.008), and percent VFA (VFA/[VFA+subcutaneous fat area]; P=0.009) were associated with more than 10% hepatic steatosis. The area under the receiver operating characteristics curve of VFA and percent VFA for detecting hepatic steatosis more than or equal to 10% were 0.803 and 0.778, respectively. Hepatic steatosis was successfully reduced to less than 10% through dietary intervention in six of the nine donor candidates.

CONCLUSIONS

Our current biopsy criteria are acceptable to select donor candidates at risk for hepatic steatosis. Visceral fat measurement can be used as an additional factor to narrow donors at risk and to monitor visceral fat reduction during dietary intervention.