Liver transplantation

Ischemic pre-conditioning in deceased donor liver transplantation: a prospective randomized clinical trial

To assess the immediate and long-term effects of ischemic preconditioning (IPC) in deceased donor. liver transplantation (LT), we designed a prospective, randomized controlled trial involving 60 donors: control group (CTL, n = 30) or study group (IPC, n = 30). IPC was induced by 10-min hiliar clamping immediately before recovery of organs. Clinical data and blood and liver samples were obtained in the donor and in the recipient for measurements. IPC significantly improved biochemical markers of liver cell function such as uric acid, hyaluronic acid and Hypoxia-Induced Factor-1 alpha (HIF-1 alpha) levels. Moreover, the degree of apoptosis was significantly lower in the IPC group. On clinical basis, IPC significantly improved the serum aspartate aminotransferase (AST) levels and reduced the need for reoperation in the postoperative period. Moreover, the incidence of primary nonfunction (PNF) was lower in the IPC group, but did not achieve statistical significance. We conclude that 10-min IPC protects against I/R injury in deceased donor LT.

Inducible left ventricular outflow tract gradient during dobutamine stress echocardiography: an association with intraoperative hypotension but not a contraindication to liver transplantation

BACKGROUND

Dobutamine stress echocardiography (DSE) is frequently used in the evaluation of cardiac risk prior to orthotopic liver transplantation (OLT). In the general cardiac population, an inducible left ventricular outflow tract gradient (LVOT Delta) during DSE has variable prognostic importance. The purpose of this study was to determine the prevalence and clinical significance of LVOT Delta in patients undergoing OLT during DSE.

METHODS

Consecutive medical records of 106 patients who had undergone OLT at our institution from January 1997 until January 2002 were retrospectively analyzed and divided into two groups based on the presence (Group I, LVOT Delta >36 mmHg) or absence (Group II, LVOT Delta< or = 36 mmHg) of a significant LVOT Delta measured during DSE. We determined any outcome differences between these two groups with regard to intraoperative hypotension, cardiac mortality, length of hospital stay, graft function, and renal function post-OLT.

RESULTS

Forty-six patients had an LVOT Delta > 36 mmHg (Group I) and 60 patients had LVOT Delta< or = 36 mmHg (Group II). Baseline demographics were similar in both groups. There was no significant overall difference in cardiac mortality between Group I versus Group II patients (0 versus 1 patient, respectively, P=0.57). Intraoperative hypotension occurred in 4 patients in Group I versus 0 patient in Group II (P=0.03). Length of stay, graft function, and postoperative renal function were similar in both groups.

CONCLUSION

A significant LVOT Delta >36 mmHg is a frequent finding occurring in 46/106 (43%) of patients who have DSE pre-OLT. Intraoperative hypotension is associated with patients having an LVOT Delta. However, post-OLT patients with significant LVOT Delta have a similar in-hospital outcome compared to patients without significant LVOT Delta.

Immature granulocyte count after liver transplantation

We evaluated the significance of immature granulocyte (IG) count during the clinical course after liver transplantation. We counted IG using the flow cytometric method with CD16, CD11b, and CD45 antibodies. Samples were obtained from 31 patients in the Department of Transplantation and Immunology, and we determined (i) the distribution of IG peak value, (ii) the distribution of IG peak time-points, (iii) the clinical background of patients with high IG, and (iv) the clinical course of high IG cases. We observed the appearance of IG (100/microl or higher) in the majority of the patients (23 out of 31 patients; 74.2%). The IG peak was detected on the 19th day after transplantation. We observed serious complications, such as melena, rejection, or severe infection, in high IG (500/microl or higher) cases. We observed instances of inflammation with low C-reactive protein (CRP) value in the presence of IG. We believe that IG is a useful marker to monitor inflammation.

Copper metabolism and biliary secretion in patients receiving orthotopic liver transplantation

BACKGROUND

The quantitative aspects of biliary copper excretion in health and disease have not been fully defined yet. The aim of the study was to evaluate copper metabolism and biliary excretion of patients who have received an orthotopic liver transplant (OLT) during the immediate postoperative period.

METHODS

We have studied retrospectively 16 patients undergoing primary OLT and eight undergoing cholecystectomy, and measured serum concentration of copper and its secretion in bile and urine by flame atomic absorption spectrometry (FAAS).

RESULTS

We found a progressive increase of biliary copper secretion rates and a corresponding lowering of urinary copper during the postoperative period. Thus, in OLT patients, the mean of biliary copper secretion on day 1 is 0.7+/-0.2 micromol/day compared with 2.3+/-1.1 micromol/day on day 7 (p<0.01) and 6.1+/-2.5 micromol/day on day 15 (p<0.0001). The rate of copper output on day 5 after surgery is about one sixth of the value reported for patients who had undergone cholecystectomy. In patients suffering an acute rejection episode, there was an abrupt fall in bile flow (<15 ml/day) and excretion of biliary copper (<1 micromol/day), accompanied by an increase of urine copper excretion (>3 micromol/day), and both were recovered when the rejection episode was solved. We found an inverse relationship between the serum bilirubin (Bt), alkaline phosphatase (ALP) and the biliary copper excretion (p<0.01), and a direct relationship with urinary copper excretion (p<0.01).

CONCLUSIONS

The copper measurements in urine and bile are non-invasive techniques, of low cost, rapid and easy to accomplish, and available in hospitals accredited for hepatic transplantation. These characteristics make these methods helpful in the monitoring of patients submitted to OLT for assessment of graft quality and subsequent outcome.

Serum bile acids in liver transplantation--early indicator for acute rejection and monitor for antirejection therapy

We studied the course of serum bile acids to investigate its reliability in the diagnosis of acute rejection after liver transplantation in relation to pathohistological findings. Serum bile acid concentration, bilirubin and transaminases were measured in 41 patients who underwent liver transplantation. Their course was correlated to liver biopsy. Group I (n = 19) patients were without acute rejection, whereas group II (n = 22) patients showed acute rejection. Bile acid concentrations in group II showed a statistically highly significant (P < or = 0.001) threefold increase 3 days prior to biopsy. Successful antirejection treatment was correlated with a statistically significant (P = 0.008) decrease of serum bile acid 1 day after initiation of therapy. Patients without acute rejection showed a baseline bile acid concentration at the time of biopsy. Bilirubin and transaminases did not show any statistically significant correlation to acute rejection. Infection did not lead to a significant bile acid increase. Our study shows that serum bile acids monitored after liver transplantation can easily be used to detect acute rejection and at the same time they reflect the success of antirejection therapy.

Liver transplantation of patients in end-stage cirrhosis

The success of liver transplantation has resulted in its widespread use for end-stage liver disease; 1- and 5-year survival rates of 70-90% and 60-80% respectively have been reported. Indications for assessment for liver transplantation are now evidence-based and early referral is recommended, correlating with improved patient survival. The management of patients on the waiting list for liver transplantation is designed to prevent complications of liver disease and to avoid therapeutic misadventures. Following transplantation, rejection and infection dominate post-operative complications, and improvements in their prevention and treatment have also correlated with improved patient survival. The development and introduction into clinical practice of a variety of immunosuppressive agents has offered a bewildering array of therapeutic options but with a lack of evidence on which to select optimal immunosuppression. Similarly, difficulties remain in the treatment of some of the complications arising from liver transplantation such as recurrence of disease and complications of immunosuppression.

Indications for and timing of liver transplantation

The tremendous success of OLT as a highly effective treatment for patients with end-stage liver disease has resulted in a rapid increase in the number of candidates for the procedure. Refinements in organ preservation, improvements in surgical technique and immunosuppression, and better postoperative management have contributed to improved survival rates. The discrepancy between the paucity of organs and the increasing numbers of potential recipients will continue to worsen until there are extraordinary breakthroughs in providing alternatives to human whole-organ livers, such as xenografts or cultured hepatocyte infusions. For now, the vast majority of patients with life-threatening liver disease are not likely to receive a liver graft. Thus, the issues of patient selection and timing of OLT have become even more relevant. Prompt referral to a transplant center is not only in the patient's best interest, but also it has been shown to be cost-effective. Over the last 30 years, it has become clear that hepatic malignancy, initially a common reason for OLT, should be an indication for transplantation only in highly selected individuals. The role of adjuvant chemotherapy needs to be defined, and proven treatment alternatives need to be developed. New antiviral agents may enable a large group of patients with chronic hepatitis B to be successfully transplanted, placing even greater demands on the already limited supply of donor livers. Hepatitis B appears to be species specific, and it is conceivable that xenotransplantation from a nonsusceptible donor species may confer protection to HBV reinfection, eliminating the problems of an inadequate donor supply. Until novel approaches, including xenotransplantation, gene therapy, or replacement of hepatic function by cultured hepatocyte infusions, become a widespread reality, future allocation policies may highlight outcome as well as urgency as a fundamental variable to determine if transplantation is reasonable. Survival rates have been shown to fall with advancing levels of urgency, resulting in a conflict between equity and efficacy in organ allocation. As waiting lists for liver transplantation continue to grow, it is becoming increasingly apparent that patients must be referred to a transplant center earlier in the course of liver disease.

Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.

The need for liver transplantation: a nationwide estimate based on consensus review

Orthotopic liver transplantation (OLT) is widely practised in developed countries. The procedure is costly, the supply of donor organs limited, and it is not known how many patients need transplantation. A community-wide estimate of the needs for OLT was performed over two years in all general hospitals in Israel. Records of 1851 patients with liver disease were screened to identify those who might eventually need OLT. The annual estimate of transplantation needs in the country was 10-15.5 per million population, with equal numbers of males and females. The addition of patients with nonreformed alcoholism and end-stage liver disease, originally set as an exclusion criteria, would have added 20% to this estimate. 37% of potential candidates were under 40 years of age at diagnosis, and about 50% were 55-64 years old. Almost 80% of patients had cirrhosis of the liver and 13.6% had fulminant hepatitis. These findings provide a basis for a national plan of OLT in Israel, and similar studies might be useful in other countries.

Role of nuclear medicine in liver transplantation

Orthotopic liver transplantation is now a very well-established technique for treating patients with end-stage liver disease. Since 1967, more than 26,000 liver transplants have been performed, including 15,000 in the United States. The overall 1-year survival rate is approximately 80% and 5-year survival is 70%. Nuclear imaging plays an important role in the management of liver transplant recipients before and after liver transplantation. The evaluation of candidates potentially includes liver-spleen scan for liver volume, multiple gated acquisition scan, adenosine or stress thallium study, bone scan, and quantitative ventilation perfusion scan for hepatopulmonary syndrome. In the post-transplant phase, the deconvolution analysis (which corrects for the problem of recirculation) is a promising tool for diagnosing rejection, although its role in the transplant population has to be established. A variety of nuclear medicine techniques are helpful in the postoperative diagnosis of biliary complications. By performing a semiquantitative analysis to discriminate hepatocyte dysfunction from biliary disease and measuring hepatocyte extraction fraction by deconvolution analysis and excretion, (T1/2 values measured by the nonlinear list squares technique) have been very promising.

[Liver transplantation and pregnancy: 1994 perspectives]

The authors report a case of pregnancy in a 24-year-old, gravida-3, para-1 patient who had previously undergone liver transplantation for alveolar echinococcosis. Pregnancy and delivery were uneventful with no obstetrical or liver complications. Pregnancy seems to have little effect on liver transplants and rejection is seldom observed. Primary maternal complications are hypertension, preeclampsia, anemia and hyperbilirubinemia. Primary fetal complications include premature delivery and growth retardation. The mode of delivery depends on the obstetrical situation. Cyclosporin may be used during pregnancy. The risk of breastfeeding has not been clearly established. Pregnancy after liver transplantation is possible after 9 to 12 months but requires strict multidisciplinary surveillance. Barrier methods remain the preferred method of contraception for liver transplant patients.

Daily determination of individual serum bile acids allows early detection of hepatic allograft dysfunction

Acute graft rejection is still a major cause of morbidity after orthotopic liver transplantation, and its diagnosis necessitates an invasive liver biopsy. Our aim has been to determine whether changes in individual serum bile acid levels after engraftment are sensitive, specific and reliable indicators of graft function and whether these changes can antedate other biochemical indicators of hepatic allograft rejection. Individual bile acids in 200 serum samples taken serially from eight adult liver transplant patients were measured. Patients with biopsy-confirmed graft dysfunction due to rejection or nonrejection causes (n = 6 episodes) had significantly higher serum concentrations of glycocholate plus glycochenodeoxycholate and taurocholate/taurochenodeoxycholate ratios than did noncomplicated grafts (n = 3). These changes antedated any other conventional biochemical parameters by at least 48 hr and were 100% sensitive and specific. None of the conventional liver function tests could match this. Acute rejection episodes (n = 3) were then compared with nonrejection causes of graft dysfunction (n = 3). In acute rejection we noted a significant increase in the concentration of glycodeoxycholate plus deoxycholate and a significant decrease in the cholate/chenodeoxycholate ratio compared with that in nonrejection graft malfunction. Both of these changes antedated any other biochemical parameters by 24 hr. In conclusion, individual serum bile acid assays, after orthotopic liver transplantation, can detect graft dysfunction resulting from any cause at an earlier time than routine biochemical tests, and they are sensitive, specific and reliable for early detection of graft dysfunction. In addition, acute rejection can be distinguished from other causes of graft dysfunction.

Chronic rejection of liver transplants revisited

We examined 27 hepatectomy specimens to assess the frequency of foam cell endovasculitis and bile duct loss in chronic rejection. Arterial lesions, defined as total occlusion by subintimal foam cells and/or fibromuscular proliferation, were found mainly in hilar and septal arteries, whereas bile duct loss, defined as the absence of bile ducts in more than 50% of portal tracts, affected mainly small tracts. Both were found in 20 livers (74%). In two livers (7%) there was significant bile duct loss but no arterial lesions, whilst in five cases (19%) there were occlusive arterial lesions but no bile duct loss. Small arteries were involved in only 10% of the cases. These results indicate that in one-third of the cases arterial and bile duct lesions develop independently of each other, suggesting different pathogenetic pathways. In addition, liver biopsy may not be pathognomonic since small arteries are involved in only 10% of cases and bile duct loss may not be extensive. In such cases the diagnosis of chronic rejection should only be made in the presence of progressive clinical deterioration.

Changing indications in liver transplantation

During the last decade orthotopic liver transplantation has become virtually a routine procedure and most centres are reporting, in elective cases, survival rates at 1 year in excess of 90%. As experience with liver transplantation has grown, attention has focused more on refining the indications for transplantation and determining the optimal time for the procedure. In patients with fulminant hepatic failure, it may still be difficult to select those patients who require liver replacement early enough in their illness so that a suitable organ can be found and the procedure carried out before the onset of irreversible complications. Alternatives to orthotopic liver transplantation, including liver support, heterotopic transplantation, partial orthotopic liver transplantation and xenografting, are being assessed. Progress too has been made in improving indications in patients undergoing transplantation for viral hepatitis and alcoholic liver disease. Nonetheless, liver replacement remains a poor substitute for prevention of end-stage liver disease. Even with advances made in immunosuppression, there are long-term sequelae as a consequence of liver transplantation, and now more recently attention is being paid to reducing the toll of immunosuppressive drugs.

Abdominal CT following liver transplantation

Computed tomography (CT) is one of several imaging modalities employed in the evaluation of complications following orthotopic liver transplantation. Abdominal CT scans were performed in 92 (48%) of the first 190 liver transplant patients at our institution. These studies were retrospectively reviewed to determine the indications for CT in this population and to determine the incidences of the various CT findings. The major indication (70%) was detection of bile leakage, hemorrhage, or abscess. The role of CT was primarily to discover such abnormal fluid collections and guide their percutaneous drainage. This article describes a wide spectrum of common and uncommon findings following liver transplantation and illustrates their CT features.