Liver transplantation: results, advances and problems

Hepatocellular carcinoma: Defining the place of surgery in an era of organ shortage

Liver resection (LR) and transplantation offer the only potential chance of cure for patients with hepatocellular carcinoma (HCC). Historically, all patients were treated by hepatic resection. With the advent of liver transplantation (LT) patients with HCC were preferentially placed on the waiting list for LT. However, early experience with LT was associated with a high rate of tumour recurrence and poor long-term survival. The increasing scarcity of donor livers resulted in restrictions being placed on tumour size, and an improvement in patient survival. To date there have been no randomised clinical trials comparing LR to LT. We review the evidence supporting LR and/or LT for HCC and discuss the role of neoadjuvant therapy. The decision of whether to resect or transplant remains debatable and is often determined by centre experience, availability of LT and donor organs.

Effect of extended cold ischemia time on glucose metabolism in liver grafts: experimental study in pigs

BACKGROUND/PURPOSE

Recovery of normal carbohydrate metabolism in the liver after transplantation is highly important. The aim of the present study was to evaluate how short and long cold ischemia (CI) time followed by warm ischemia (WI) impact intrahepatic glucose metabolism in a pig liver transplantation model.

METHODS

Twenty-six animals were divided into two transplantation groups: group I with a liver ischemia time of 5 h (n = 6), and group II with 15 h of liver ischemia (n = 7). Intrahepatic microdialysis samples were collected throughout the experiment at 20-min intervals, during the donor operation, cold preservation, liver implantation, and liver reperfusion in the recipient. Glucose, lactate, and pyruvate concentrations were analyzed and the lactate/pyruvate ratio (L/Pr) was calculated.

RESULT

There were no changes in glucose levels during CI. However, during WI, glucose and lactate increased and the increase was significantly higher in the group with longer CI (P < 0.01). The L/Pr increased at the beginning of CI but accelerated to increase during WI in both groups, with significantly prolonged and higher levels in the group with longer CI (P < 0.01).

CONCLUSIONS

Extended CI results in increased intrahepatic glycogenolysis, delayed restoration of aerobic glycolysis, and prolonged anaerobic glycolysis shortly after reperfusion. Improvements in glycogen protection and faster restoration of aerobic metabolism during preservation and reperfusion time seem to be necessary in order to improve liver preservation protocols per se.

Outcome from molecular adsorbent recycling system (MARS) liver dialysis following drug-induced liver failure

RATIONALE

Fulminant liver failure from drug ingestion is associated with a high mortality, and the introduction of liver transplantation has improved the mortality significantly if done in a timely fashion. Recently, molecular adsorbent recycling system (MARS) liver dialysis has been introduced as a support for liver failure with varying results. We review our experience with drug-induced liver failure and the impact of MARS liver dialysis on the outcome, in a setting where cadaveric liver transplantation is rarely available.

RESULTS

A total of 13 patients were treated, and 40 sessions of MARS liver dialysis were conducted in the intensive care unit. The majority of cases were because of herbal medicine toxicity. Total bilirubin, conjugated bilirubin, and delta bilirubin were significantly reduced, with no change in unconjugated bilirubin. All patients satisfied the criteria for urgent liver transplantation with an average Model End Stage Liver Disease (MELD) score of 35. Only one patient received a liver transplantation from a live donor (right lobe). Overall mortality was 85%. Median time-to-death from the start of MARS was 8 days.

CONCLUSIONS

MARS liver dialysis in a setting without timely liver transplantation is associated with a poor outcome. It does, however, provide a window of time for consideration of living donors in the setting of limited cadaveric donors.

Thrombocytopenia after liver transplantation

BACKGROUND

Thrombocytopenia after orthotopic liver transplantation (OLT) is a well recognized and prevalent early postoperative complication. The etiology, as well as the effect of this phenomenon on transplant outcome, however, are vague. The aims of this study are to identify factors contributing to thrombocytopenia and to ascertain whether there is any correlation with early rejection and ultimate survival.

METHODS

This study examines 541 OLTs (541 grafts in 494 patients) that were transplanted at the University of Miami during the 3-year period from June 1994 to September 1997. The patients with severe postoperative thrombocytopenia (nadir platelet count [PLT] < 20,000/mm3), as well as the whole group of patients, were analyzed. The preoperative PLT, intra-operative platelet transfusion requirements, cross-match, recipient and donor cytomegalovirus (CMV) status, infusion of donor bone marrow cells (DBMC), occurrence of early rejection episodes (in the first posttransplant month), and re-transplantation were factors examined for any association with thrombocytopenia. Total bilirubin (TB) and direct bilirubin (dB), hematocrit, white blood cell count (WBC), aspartate aminotransferase and alanine aminotransferase, determined on the day that platelets reached a nadir (nadir day), were also analyzed.

RESULTS

In 90.9% of the cases, there was a 56.5%+/-23.5% fall in platelets in the immediate posttransplant period (first 2 weeks), but the mean PLT exceeded preoperative levels during the 3rd and 4th postoperative weeks. The nadir of the drop in the PLT most commonly occurred on posttransplant day 4. For preoperative PLT, platelet transfusions during the operation, re-transplantation, early rejection, cross-match, and recipient CMV status, there was significant statistical correlation with any degree of postoperative thrombocytopenia. Four of these factors, preoperative PLT, intra-operative platelet transfusions, re-transplantation, and early rejection, were found to be independently associated with thrombocytopenia in general. None of them was found to be independently correlated with severe thrombocytopenia. A statistically significant correlation between bilirubin and WBC on the nadir day and the degree of thrombocytopenia was observed. No correlation was found between infusion of DBMC or donor CMV serology and thrombocytopenia. Both the nadir PLT and the percentage of the platelet fall were independent predictive factors (p<0.01 and 0.005, respectively) of patient and graft survival.

CONCLUSIONS

Thrombocytopenia in the immediate posttransplant period is correlated with low preoperative PLT, massive platelet transfusions, and re-transplantation. These factors reflect a poor preoperative condition. There is also a correlation with allograft dysfunction, rejection, and poorer patient and graft survival. A rise in the mean PLT after the 2nd postoperative week reflects proper graft function.

Persistent hypersplenism early after liver transplant: the role of splenectomy

BACKGROUND

Transient thrombocytopenia is common after liver transplantation, but persisting thrombocytopenia worsens the prognosis after transplant.

METHODS

Two patients underwent splenectomy for persistent thrombocytopenia early after liver transplantation. The first patient had a platelet count of 17,000/mm3 on postoperative day (POD) 6; her hemoglobin and white blood cell counts were normal. Work-ups including bone marrow aspiration, Coombs test, and antiplatelet antibody test were negative. On POD 9, she had abdominal bleeding with a platelet count of 17,000/mm3 despite repeated platelet transfusions, and splenectomy was done. The second patient had a platelet count of 3000/mm3 on POD 14, white blood cell was 1600/mm3, and hemoglobin was 7.7 g/dl. Bone marrow biopsy revealed hypercellular marrow. Because his platelet count remained at 2000/mm3 despite empiric treatment with intravenous immune globulin and methylprednisolone, splenectomy was performed.

RESULTS

The first patient's platelet count rose to 155,000/mm3 by POD 8. The second patient's platelet count reached 210,000/mm3 on POD 5. Neither patient has had an episode of thrombocytopenia at 36 and 32 months after splenectomy.

CONCLUSIONS

Splenectomy can be used after liver transplantation for severe, persistent thrombocytopenic states that cannot be attributed to sepsis, intravascular coagulation, immunological causes, or drug effects.

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.

Thrombocytopenia post liver transplantation. Correlations with pre-operative platelet count, blood transfusion requirements, allograft function and outcome

This study reports that thrombocytopenia is a universal phenomenon post hepatic transplantation. In 53 consecutive adult patients undergoing liver transplantation the platelet count fell by a mean of 63% (157 x 10(9)/l to 50 x 10(9)/l). The platelet count reached a nadir at Day 5 post-transplant but returned to pre-operative levels by Day 14. Non-parametric regression analysis found that pre-operative platelet count, blood transfusion requirements and maximum post-operative ALT values were independent predictors of the percentage fall in platelet count. No correlation was seen with length of graft cold ischaemic time or the use of University of Wisconsin (UW) solution. The nadir day correlated with maximum post-operative bilirubin and ALT, graft ischaemic time and use of UW solution. Maximum post-operative ALT was also an independent predictor of nadir platelet count. It was observed that patients who did not survive the hospital admission had lower post-operative platelet counts and these did not return to pre-operative levels by Day 14. The percentage fall in platelet count was an independent predictor of survival. Severe thrombocytopenia was associated with cerebral haemorrhage in 3 patients. This report provides evidence that allograft dysfunction (maximum post-operative bilirubin and/or AST/ALT) was the most consistent independent predictor of the nadir platelet count, nadir day and percentage fall in platelet count post liver transplantation although the exact mechanism(s) of the platelet changes remain uncertain.