Relationship between the diagnosis, preoperative evaluation, and prognosis after orthotopic liver transplantation

[Association between the use of blood components and the five-year mortality after liver transplant]

BACKGROUND AND OBJECTIVES

Liver transplant (LT) surgery is associated with significant bleeding in 20% of cases, and several authors have demonstrated the risks related to blood components. The objective of the present study was to evaluate the impact of using blood components during hospitalization in five-year survival of patients undergoing LT.

METHODS

One hundred and thirteen patients were evaluated retrospectively. Several variables, including the use of blood components intraoperatively and throughout hospitalization, were categorized and evaluated by univariate analysis using Fisher's test. A level of significance of 5% was adopted. Results with p < 0.2 underwent multivariate analysis using multinomial logistic regression.

RESULTS

Parenchymal diseases, preoperative renal dysfunction, and longer stay in hospital and ICU are associated with greater five-year mortality after LT (p < 0.05). Unlike the intraoperative use of blood components, the accumulated transfusion of packed red blood cell, frozen fresh plasma, and platelets during the entire hospitalization was associated with greater five-year mortality after liver transplantation (p < 0.01).

CONCLUSIONS

This study emphasizes the relationship between the use of blood components during hospitalization and increased mortality in five years after LT.

Long-term outcome of human leukocyte antigen mismatching in liver transplantation: results of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

A perfect or nearly perfect human leukocyte antigen (HLA) match has been associated with better immediate and long-term survival of diseased donor kidney transplants. However, the effect of HLA matching for hepatic allografts remains poorly defined. Using data from the National Institutes of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database, we investigated the association between HLA mismatches and hepatic allograft survival, disease recurrence, and immunosuppression interactions. A, B, and DR loci were used to calculate total mismatch scores of 0 (no mismatches in any loci) to 6 (mismatches in all loci). Seven hundred ninety-nine adults (male, 55%; female, 45%) underwent 883 liver transplants. The 10-year graft survival according to total mismatch score was as follows: 0-2, 60%; 3-4, 54%; and 5-6, 57%. There was a negative effect of mismatching at the A locus on patient survival, with shorter survival for patients with 1 or 2 mismatches compared with 0 mismatches [P = 0.05, hazard ratio (HR) = 1.6]. Patients on tacrolimus with 1 or 2 mismatches at B or DR loci appeared to have increased rates of patient and graft survival compared to patients with 0 mismatches, with the appearance of a protective effect of tacrolimus (HR = 0.67). The effect of HLA mismatching was more pronounced on certain disease recurrences. DR-locus mismatch increased recurrence of autoimmune hepatitis (P = 0.01, HR = 4.2) and primary biliary cirrhosis (P = 0.04, HR = 2). Mismatch in the A locus was associated with more recurrence of hepatitis C virus (P = 0.01, HR = 1.6) and primary sclerosing cholangitis (P = 0.03, HR = 2.9).

CONCLUSION

Mismatching at the A locus decreases patient survival in liver transplant recipients, and mismatching at the DR and A loci affects recurrence of autoimmune liver diseases and hepatitis C, respectively.

Aerobic capacity is associated with 100-day outcome after hepatic transplantation

The shortage of donor organs highlights the need to better identify patients most likely to benefit from hepatic transplantation. Reduced aerobic capacity (decreased peak oxygen consumption [VO(2)] during symptom-limited cardiopulmonary exercise testing) is frequently present in cirrhosis. Peak VO(2) during cardiopulmonary exercise testing may predict short-term outcome after hepatic transplantation. Symptom-limited testing was performed on a cycle ergometer (continuous ramp protocol) and VO(2) determined using a metabolic cart. One hundred fifty-six patients were tested; 59 subsequently underwent hepatic transplantation. Results showed that survivors and nonsurvivors were similar in age, duration of liver disease, Child-Pugh score, MELD score, resting cardiovascular function, pulmonary function, and gas exchange. The 6 (10.2%) patients dying within 100 days of transplantation were more likely to have reduced aerobic capacity (peak VO(2) <60% predicted and VO(2) at anaerobic threshold [VO(2)-AT] <50% predicted peak VO(2)) compared to survivors (4/6 vs. 7/53, P <.01). Using a multiple logistic regression model controlling for duration and severity of liver disease and time to transplantation, reduced aerobic capacity was independently associated with 100-day mortality. In conclusion, reduced aerobic capacity during cardiopulmonary exercise testing is associated with decreased short-term survival after hepatic transplantation. Further study is needed to determine if cardiopulmonary exercise testing can be used to improve allocation of donor organs. To ensure optimum allocation of donor organs, it is important to identify patients most likely to benefit from transplantation. Investigators have identified a number of preoperative, intraoperative, and postoperative factors that predict increased risk for postoperative mortality. Unfortunately, predictive accuracy has not been high, and the timing of factor identification does not optimize organ utilization. Identification of predictors of survival at the time of listing for transplantation might lead to better resource allocation.

Significance of cytomegalovirus for long-term survival after orthotopic liver transplantation: a prospective derivation and validation cohort analysis

BACKGROUND

Cytomegalovirus (CMV) infection and disease has been found to be associated with decreased graft and patient survival among heart transplant recipients. We sought to explore the effect of CMV infection and disease on long-term survival in orthotopic liver transplant (OLT) recipients using a derivation and validation cohort.

METHODS

For derivation-validation modeling, we used data collected from two prospectively followed cohorts as the basis for multivariate analyses: 167 OLT recipients from the Boston Center for Liver Transplantation (the derivation set; median follow-up: 5.5 years, mortality: 40%) and an independent cohort of 294 OLT recipients from the Mayo Clinic (the validation set; median follow-up: 4.8 years, mortality: 27%).

RESULTS

Underlying liver disease other than primary biliary cirrhosis or sclerosing cholangitis, number of units of red blood cells administered during transplantation, and donor CMV seropositivity were the pre- and intratransplant variables independently associated (P<0.01) with decreased long-term survival in the derivation cohort. For variables collected up to 1 year after transplantation, the need for retransplan. tation, CMV pneumonia, invasive fungal disease, and underlying liver disease other than primary biliary cirrhosis or sclerosing cholangitis were independently associated (P<0.01) with decreased long-term survival in the derivation cohort. The magnitude of the relationship of each pre-, intra-, and posttransplant factor with survival, as measured by the relative risk, did not significantly differ between the derivation and validation cohorts. The derivation model, incorporating pre-, intra-, and posttransplant factors, had receiver operating characteristic areas of 73% and 74% for 5-year mortality in the derivation and validation cohorts, respectively.

CONCLUSIONS

Data from a derivation and an independent validation cohort demonstrate that CMV factors (reflected by either donor CMV seropositivity at transplantation, CMV pneumonia, or CMV disease within the first posttransplant year) are independently associated with decreased long-term survival in OLT recipients.

Liver transplantation in patients with non-biliary cirrhosis: prognostic value of preoperative factors

BACKGROUND/AIM

The type of disease indicating liver transplantation is one of the most powerful predictors of postoperative survival. This may be an important problem in evaluating the prognostic significance of other factors when patients with liver diseases of very different nature are jointly studied. To minimize this bias, the present study aimed to investigate preoperative prognostic factors in liver transplantation only in patients with non-biliary cirrhosis.

METHODS

Twenty-three preoperative standard clinical and laboratory variables were analyzed as possible prognostic factors in 162 patients receiving liver transplantation for non-biliary cirrhosis. Data for seven splanchnic and systemic hemodynamic variables were also analyzed in 55 patients.

RESULTS

Using univariate analyses followed by a multivariate analysis, only preoperative blood urea nitrogen (BUN) reached statistical significance as an independent predictor of hospital survival; the survival rate at the end of hospitalization being 90% in patients with BUN< or =25 mg/dl and 65% in patients with BUN>25 mg/dl (p=0.0008). Similarly, preoperative BUN was the only variable independently predicting cumulative long-term survival, with an 87% survival probability at 1 year and 73% at 4 years in patients with BUN< or =25 mg/dl, and 61% and 49%, respectively, in patients with BUN>25 mg/dl (p=0.0014).

CONCLUSIONS

Renal function parameters are the most powerful preoperative predictors of survival after liver transplantation in patients with non-biliary cirrhosis. It is suggested that liver transplantation is indicated in these patients before marked renal dysfunction develops.

The potential role of dual-energy X-ray absorptiometry in the assessment of body composition in cirrhotic patients

Very little information is available on body composition in patients with cirrhosis. Difficulties arise in studying these patients because they tend to retain fluid and this results in changes in tissue density and in the hydration fraction of fat-free mass. As the classic body composition techniques rely on the assumption that these variables remain constant, use of these methods will result in either under- or overestimates of body composition variables. Use of multicomponent models, employing two or more measurement techniques, will obviate the need for some of the assumptions inherent in the use of single techniques, thereby increasing the accuracy of the assessments without loss of precision. Dual-energy x-ray absorptiometry can be used to measure total body bone mineral, fat, and fat-free soft tissue mass. In healthy individuals excellent agreement is observed between data obtained using this technique and data obtained from the more established reference methods. However, the degree to which the absorptiometry measurements of soft tissue are sensitive to the hydration is not known. Thus, in order to assess this method of body composition analysis in patients with chronic liver disease, a multicomponent model must be devised which incorporates the absorptiometry technique and allows cross-validation of the individual component measures.

Increased infections in liver transplant recipients with recurrent hepatitis C virus hepatitis

Infectious complications in patients with recurrent hepatitis C virus (HCV) hepatitis after liver transplantation were prospectively assessed and compared with those of all other liver transplant recipients without HCV hepatitis operated on during the same period. Major infections occurred in 64% (14/22) of the patients with recurrent HCV hepatitis versus 38% (30/78) of all other patients (P = 0.04). Patients with recurrent HCV hepatitis had significantly more episodes of major infections (mean 1.45 episodes/patient vs. 0.51 episodes/patients, P = .003) and were more likely to have recurrent episodes of major infections (45%, 10/22, vs. 10%, 8/78, P = 0.005) than all other patients, respectively. The incidence of major bacterial infections was not higher in patients with recurrent HCV hepatitis (41% vs. 28%, P = NS); however, incidence of fungal infections was higher (18% vs. 6%, P = 0.10) and incidence of cytomegalovirus disease was significantly higher (32% vs. 9%, P = 0.012) in patients with recurrent HCV hepatitis as compared with all other patients. Late infections, i.e., those occurring > 6 months after transplantation, were significantly higher in patients with recurrent HCV (27% vs. 6%, P = 0.011). Rejection episodes occurring within 6 months after transplantation were higher in patients with recurrent HCV hepatitis (P = 0.09); however, the intensity of immunosuppression as measured by corticosteroid boluses and cycles was not significantly different in these patients when compared with all other patients. Aminotransferase levels were significantly higher in patients with HCV recurrence than in other patients. We conclude that recurrent HCV hepatitis after liver transplantation is associated with a high incidence of infections due to pathogens associated with depressed cell-mediated immunity. Future studies should assess the exact nature of the suppressive effect on host defense in recurrent HCV hepatitis.

The assessment of body composition in patients with cirrhosis

Very little information is available on body composition in patients with cirrhosis. Difficulties arise in studying these patients because they tend to retain fluid and this results in changes in tissue density and in the hydration fraction of fat-free mass. As the classic body composition techniques rely on the assumption that these variables remain constant, use of these methods will result in either under- or overestimates of body composition variables. Use of multi-component models, employing two or more measurement techniques, will obviate the need for some of the assumptions inherent in the use of single techniques, thereby increasing the accuracy of the assessments, without loss of precision.

[Role of hepatocellular insufficiency and kidney failure on nutritional management]

Chronic liver disease as well as chronic renal failure are responsible for abnormal nutrient metabolism and high rates of undernutrition. Although surgery is frequently required in such patients, the perioperative nutritional management has not yet been extensively studied in these conditions. During chronic liver disease, preoperative nutritional status and postoperative outcome are correlated. However, nutritional status can only be considered as one out of several factors of the prognosis, including the grade of liver insufficiency and the type of surgical procedure. Thus, it is difficult to evaluate the real influence of undernutrition on postoperative outcome. Similarly, the usefulness of preoperative nutrition is not definitely demonstrated in this condition. The nutritional requirements of patients with liver cirrhosis are estimated to be protein 1g and 30-35 kcal.kg-1.d-1. The duration of nutritional supplementation before surgery may not exceed 10 days. Postoperative parenteral nutrition seems to be well tolerated during chronic liver disease. Although some data in the literature suggest that it may be of interest after liver transplantation, the efficacy of postoperative parenteral nutrition needs to be proven in larger series. In chronically uraemic patients, the effects of undernutrition on postoperative morbidity and mortality have been poorly studied. Infectious complications after renal transplantation are favoured by several factors, including immunosuppressive therapy and malnutrition. The efficacy as well as the tolerance of perioperative nutritional support in patients with chronic renal failure are poorly known. In haemodialysis patients, candidates for renal graft, the nutritional status is usually well preserved when the recommended nutritional needs are provided: proteins 1.2-1.4 g and 35-40 kcal.kg-1.d-1.

Evidence for involvement of oxygen free radicals in bile acid toxicity to isolated rat hepatocytes

The mechanisms by which hydrophobic bile acids are toxic to the liver are unknown. To determine whether the generation of free radicals is involved in the hepatotoxicity of bile acids, freshly isolated rat hepatocytes were incubated with individual bile acids (100 to 200 mumol/L) for 4 hr. Hepatocyte viability (trypan blue exclusion) declined to 40% to 50% in incubations with taurochenodeoxycholic acid and taurolithocholic acid, whereas taurocholic acid and tauroursodeoxycholic acid were not toxic. Lipid peroxidation was significantly associated with the loss of cell viability. Preincubation with different antioxidants-D-alpha-tocopheryl succinate, D-alpha-tocopherol, diphenyl-p-phenylenediamine, superoxide dismutase, catalase, superoxide dismutase + catalase, deferoxamine or apotransferrin-protected against the loss of viability and inhibited lipid peroxidation in cells incubated with 200 mumol/L taurolithocholic acid. alpha-Tocopheryl succinate added after 90 min of incubation with taurolithocholic acid ameliorated further hepatocyte toxicity and lipid peroxidation. Incubation of hepatocytes with 500 mumol/L of taurochenodeoxycholic acid or taurolithocholic acid under a low oxygen tension (9% O2) similarly caused lipid peroxidation and cell injury that was reversed by preincubation with D-alpha-tocopherol. These data suggest that oxygen free radicals may be involved in the pathogenesis of bile acid hepatotoxicity.

EEG in liver transplantation: visual and computerized analysis

We prospectively evaluated 40 liver transplant candidates (including 28 recipients) with visually scored or computerized EEG. As expected, EEG frequencies rose significantly after successful transplant (P < 0.01). For all subjects, but especially for the transplant recipients, higher frequencies on computerized EEG at baseline had a strong association with survival at 18 months (P < 0.001). A logistic regression model allowed estimation of the odds for survival and indicated less than 50% long-term survival with central-occipital mean frequencies below 7.6 c/sec. Visual EEG scores closely paralleled the quantitative results, but only the latter were amenable to formal statistical analysis. EEG had much stronger predictive value for survival than serum albumin, although albumin improved more significantly in the months after transplantation.

Liver transplantation (1)

Advances in the management of both chronic and acute hepatic disease have been made possible and even mandated by the development of liver transplantation. The clinical use of transplantation has proceeded at a rapid pace since a Consensus Development Conference of the National Institutes of Health concluded in June 1983 that liver transplantation had become a service and not simply an experimental procedure.1

The liver can be transplanted as an extra (auxiliary) organ at an ectopic site, or in the orthotopic location after the removal of the host liver (Fig. 1 ). This article will focus primarily on the orthotopic procedure. However, there has been renewed interest in the auxiliary operation, which will be discussed separately.

Liver transplantation

Liver transplantation has become an established form of therapy for patients with almost any type of irreversible and severe liver disease. The remarkable success of liver transplantation has resulted from recent advances in immunosuppressive therapy, surgical techniques, and patient selection. Additional progress has been made in the management of the complex postoperative medical complications that may occur. Indeed, liver transplantation has contributed significantly to an improved quantity and quality of life for many patients with liver disease.

Liver transplantation for primary biliary cirrhosis

Liver transplantation is an effective treatment for PBC. The Pittsburgh experience is reported, with 1- and 5-year survival of 75.62% and 70.71%, respectively. Recurrence of PBC, when it occurs, has not been of clinical significance. Transplantation markedly improves chances for survival, an advantage that is demonstrable in all of the risk groups. Rehabilitation is achieved after transplantation in approximately 90% of the patients. Some clinical variables are associated with a poorer outcome and indicate the need for earlier treatment.

[Liver transplantation in adults: postoperative management and development during the first months]

Recent improvements in the results of orthotopic liver transplantation (OLT) have made this a well-accepted treatment for patients with severe hepatic failure. Current problems encountered following OLT are discussed. Immediate complications comprise surgical bleeding, primary graft non-function, and graft failure due to hepatic artery occlusion. Secondary complications are frequent. Surgical ones include biliary and vascular (hepatic artery thrombosis most often) problems, as well as intra-abdominal abscesses associated with gastrointestinal perforation, biliary leak, graft ischaemia or an infected haematoma. 40% of patients having undergone OLT will be reoperated on, 2/3 of them within 3 months. Non-surgical complications are mostly pulmonary. The risk of pneumonitis is increased by prolonged mechanical ventilation; it is always potentially disastrous in the immunosuppressed, transplanted patient. Hypertension is also often seen in the early postoperative period; it requires prompt treatment. Early renal impairment after OLT is common, and of better prognosis than late onset renal failure, which is generally associated with shock, graft failure, sepsis or use of nephrotoxic agents. Seizures, usually only one, occur in about 10% of patients; recovery is complete. Encephalopathy with intracranial oedema related to fulminant hepatitis has a worse prognosis, but survival figures are quite encouraging. Three type of rejection are described after OLT: 1) severe accelerated rejection (very rare), 2) acute rejection encountered in about 70% of patients over the first 3 months, and 3) late rejection, which can lead to the vanishing bile duct syndrome (VBDS). Diagnosis of rejection is made by liver biopsy. Prophylactic immunosuppression includes cyclosporin, methylprednisolone and azathioprine. Cyclosporin toxicity and drug interactions are reviewed. Treatment of acute rejection episodes comprises an initial bolus of high doses of corticoid drugs; if there is no response, antilymphocyte globulin or monoclonal antibodies may have to be used. Infection is the main cause of death following OLT. Early infections, mostly intra-abdominal and pulmonary, are bacterial or fungal. Vital (especially CMV) and other opportunistic infections occur generally after the second week. Retransplantation, carried out in 10 to 25% of patients, may be urgent in case of primary graft failure, or hepatic artery thrombosis associated with graft failure, or hepatic artery thrombosis associated with graft failure. Other indications are early graft rejection with severe hepatic dysfunction, chronic rejection with severe VBDS, and recurrence of the initial disease.