Liver transplantation in the United States from 1987-1998: updated results from the Pitt-UNOS Liver Transplant Registry.

CENTERS: Between 1988-1997, the total number of liver transplantations performed in the US more than doubled from 1,713-4,158, and the number of centers performing liver transplantations increased from 59-107. In recent years, the yearly net gain in the number of operating centers has slowed, and the differences in LT volume across centers has remained stable. OUTCOMES: During the first year following transplantation, patient survival was approximately the same for adults and children, while retransplantation-free survival was poorest among children. Thereafter, survival declined more rapidly among adults than among children. SURVIVAL AMONG PEDIATRIC RECIPIENTS: The estimated cumulative probability of a pediatric recipient surviving for 10 years following transplantation was .80, and surviving for 10 years without retransplantation was .59. In general, few deaths or retransplantations were observed more than 4 years after the initial transplantation. Factors independently associated with patient and retransplantation-free survival among children were year of transplantation, recipient age, being on life support while awaiting transplantation, primary liver disease, serum creatinine, total bilirubin, donor age, donor race, and warm ischemic time. Recipient race, a multi-organ transplant procedure, and serum albumin level were significantly associated with patient survival only. The use of a reduced-size or split liver for transplantation in children was independently associated with retransplantation-free survival, but not with patient survival. SURVIVAL AMONG ADULT RECIPIENTS: The estimated cumulative probability of an adult recipient surviving for 10 years following transplantation was .61, and surviving for 10 years without retransplantation was .46 with the median retransplantation-free survival time estimated at 9.2 years. Factors independently associated with patient and retransplantation-free survival among adults were year of transplantation, recipient age, recipient race, recipient location awaiting transplantation, primary liver disease, serum creatinine and albumin levels, hepatitis B surface antigen status, donor age, donor anti-CMV status, warm ischemic time, sex match, pretransplant ventilator or inotrope use, and recipient anti-HCV status. Pre-transplant bilirubin level, a multi-organ transplant procedure, and the finding of an incidental tumor were significantly associated with patient survival; and donor race, ABO match, and uncontrolled variceal bleeding were associated with retransplantation-free survival.

Long-term patient and retransplantation-free survival by selected recipient and donor characteristics: an update from the Pitt-UNOS Liver Transplant Registry.

CENTERS: Between 1988 and 1996, the total number of liver transplantations performed in the United States more than doubled, and the number of centers performing liver transplantations increased from 58 to 106. The yearly net gain in number of centers has slowed substantially in recent years, and the reduced differences in volume per center reported previously has continued through 1996. SURVIVAL AMONG PEDIATRIC RECIPIENTS: The estimated cumulative probability of a pediatric recipient surviving for 9 years following transplantation was .71, and surviving for 9 years without retransplantation was .58. In general, few deaths or retransplantations were observed more than 5 years following the initial transplantation. Factors independently associated with patient and retransplantation-free survival among children were year of transplantation, recipient age, location awaiting transplantation, primary liver disease, pre-LT serum creatinine, pre-LT bilirubin, and donor age. Recipient race and multiorgan transplantation were significantly associated with patient survival. Interestingly, of the 23 multi-organ recipients who survived at least 3 years, none died or required retransplantation. SURVIVAL AMONG ADULT RECIPIENTS: The estimated cumulative probability of an adult recipient surviving for 9 years following transplantation was .55, and surviving for 9 years without retransplantation was .48. Though the one-year survival rate among adults was slightly better than among children, long-term survival was substantially worse. Factors independently associated with patient and retransplantation-free survival among adults were year of transplantation, recipient age, race, location awaiting transplantation, primary liver disease, pre-LT creatinine, pre-LT albumin, recipient HBsAg status, donor age, donor anti-CMV status, ABO match, and sex match. Pre-LT bilirubin was significantly associated with patient survival, and pre-LT prothrombin time was associated with retransplantation-free survival.

Recent findings concerning liver transplantation in the United States.

CENTERS: The growth in liver transplantation activity recorded by the Pitt-UNOS Liver Transplant Registry since October 1987 continued. However, for the first time since the establishment of the LTR, there was no net gain in the number of centers in 1995. The large differences in volume per center also diminished. PATIENTS: The age of pediatric recipients increased significantly in 1995, due to a decrease in the proportion of recipients under age one. For the first time, in 1995 fewer than half of transplantations in children were for biliary atresia. The addition of bone marrow transplantations, for which collection began in 1994, accounted for half of the multi-organ transplantations in 1995. Many of the characteristics examined for adult recipients changed between 1994 and 1995. The proportion of Hispanic recipients increased. The mean age of adult recipients continued to increase, but there was not a significant change in the prevalence of positive CMV serology. Reversing a trend, the proportion of adult recipients awaiting transplantation outside of the hospital decreased between 1994 and 1995. As with children, the proportion of adult multi-organ transplantations which included bone marrow increased. Hepatitis non-A, non-B, or C and alcoholic liver disease (ALD) were the most common reasons for LTX in 1995. While the proportion of recipients with ALD alone decreased slightly, the proportion with ALD and hepatitis C increased from 1994 to 1995. OUTCOME: The cumulative probability of surviving (without retransplantation) for 8 years after initial transplantation was .71 (.60) for pediatric recipients. The one-year survival for pediatric recipients changed significantly over time with the increase from 1994 to 1995 being similar to the increase between 1994 and prior years. Independent risk factors for survival among children included age, race, location awaiting transplantation, primary liver disease, and serum creatinine. Year of transplantation and bilirubin were independently associated with retransplantation-free survival, whereas multi-organ transplantation was associated with poorer patient survival. The cumulative probability of adults surviving (without retransplantation) for 7 years following LTX was .58 (.50). Independent risk factors were year of transplantation, age, location awaiting transplantation, primary liver disease, albumin, creatinine, and ABO match. Black recipients had poorer patient survival rates than other recipients whereas increased prothrombin time and CMV-positive donors were risk factors for retransplantation or death.

The relationship between outcome of liver transplantation and experience in new centers.

For several medical interventions, increasing experience results in improved outcome. This finding may result from better patient selection or increased skill levels. This report examines whether there is a relationship between center experience and patient outcome for liver transplantation, and if so, whether the relationship is explained by patient or donor selection or level of experience required to obtain optimal results. The United Network for Organ Sharing Scientific Liver Transplant Registry includes all procedures performed in the United States since October 1987. The date of the first transplantation and the number of operations performed were used to define 42 new and 27 experienced centers. Within new centers, experience was quantified by the sequence number of each transplantation. Characteristics of 6,180 recipients and donors were compared between new and experienced centers using the chi 2 test for association. A linear trend test identified whether these characteristics varied with experience within new centers. The independent association between experience in new centers and perioperative mortality was examined using logistic regression. Patient and donor selection criteria differ between experienced and new centers and change within new centers as experience is gained. Adjusting for calendar year and various patient and donor characteristics, perioperative mortality rates decrease in new centers as experience is gained. After 20 transplantations are performed, perioperative mortality in new centers is not significantly different than that in experienced centers. Criteria for recipient and donor selection change as centers gain experience. Despite these differences and improvements that have occurred over time, increasing experience in centers performing liver transplantations is associated with reduced perioperative mortality.

An update on liver transplantation in the United States: recipient characteristics and outcome.

The growth in liver transplantations recorded by the Pitt-UNOS Liver Transplant Registry since October 1987 continues as does the net growth of new centers. Characteristics of pediatric recipients in 1994 were compared to those of previous years and no significant differences were found for gender, race or age. The majority of pediatric recipients in 1994 awaited transplantation at home. The most common indication for liver transplantation in children was bilary atresia, though the proportion of recipients with this primary liver disease decreased significantly. Significant increases were noted in the proportions of pediatric recipients with autoimmune disease (though this remains a relatively uncommon indication) and fulminant liver failure. There was a significant decrease in the proportion of children who received ABO-incompatible livers. Many of the characteristics examined for adult recipients changed over time. The proportion of male recipients continued to increase. The mean age of adult recipients continued to increase, likely contributing to the increased prevalence of positive CMV-serology. The proportion of adult recipients awaiting transplantation outside the hospital increased over time. The increase in the proportion of multiorgan transplantations was in large part due to the increased reporting of bone marrow/liver transplants in 1994. Hepatitis non-A, non-B, or C and alcoholic liver disease were the most common reasons for LTX. The proportions of recipients with hepatitis B, fulminant liver failure and malignancies, indications with the poorest survival, all declined significantly. The cumulative probability of surviving (without retransplantation) for 7 years after initial transplantation was 0.70 (0.57) for pediatric recipients. Despite changes in recipient characteristics, the one-year survival for pediatric recipients did not change significantly over time. Significant differences in survival, unadjusted for other factors, were found by age (the youngest recipients had the worst survival), location awaiting transplantation (greater medical intervention just prior to transplantation led to poorer survival), multiorgan transplantation, primary liver disease (survival was worst for recipients transplanted due to malignancies, and best for patients with metabolic diseases), and donor/recipient ABO matching (survival was best for recipients of livers from donors with the same blood type). These results are similar to those previously reported for 4- and 5-year survivals. The cumulative probability of adults surviving (without retransplantation) for 7 years following LTX was 0.59 (0.52). Significant differences in survival, unadjusted for other factors, were found for year of transplantation (recipients in 1994 had better one-year survival than those transplanted in previous years), sex (males had worse survival than females), race (Blacks and Asians had the poorest survivals), age (recipients 50 years of age and older had the poorest survival), location awaiting transplantation (greater medical intervention just prior to transplantation led to poorer survival), multiorgan transplantation (recipients of organs in addition to the liver had worse patient survival than recipients of liver only), and primary liver disease (the best survival was for cirrhosis due to cryptogenic or cholestatic cirrhosis, the poorest survival was for malignancies and hepatitis B). Similar results were also reported previously for 4- and 5-year survivals.

Liver transplantation in the United States: results from the National Pitt-UNOS Liver Transplant Registry. United Network for Organ Sharing.

The growth in liver transplantations recorded by the Pitt-UNOS Liver Transplant Registry since October 1987 continues, and in 1993 the rate of increase was greater than it had been in recent years. This is in spite of the fact that the net growth of new centers was smaller in 1993 than in any previous year examined. Pediatric recipients in 1993 were compared with those in previous years, and no significant differences were found for sex, race, or age. In contrast to prior years, the majority of pediatric recipients in 1993 awaited transplantation at home. The most common indication for liver transplantation in children was biliary atresia, although the proportion of recipients with this primary liver disease decreased slightly in 1993. Significant increases were noted in the proportions of pediatric recipients with fulminant liver failure, and hepatoblastoma. Significantly fewer children received ABO-incompatible livers in 1993 compared with prior years, part of which may be a function of the increasing use of living-related donors. Many of the characteristics examined for adult recipients had different distributions in 1993 than in prior years. The proportion of White recipients declined in 1993, due to increases among Black and Hispanic recipients. The mean and median ages of adult recipients continued to increase because of the increasing proportion of recipients aged 60 and over. The proportion of adult recipients awaiting transplantation outside of the hospital continued to increase in 1993. The increase in the proportion of recipients with positive CMV serology is likely due to the increasing age of the recipients in 1993. A smaller proportion of multiorgan transplantations was performed in 1993, due to the elimination of procedures involving only the liver and pancreas. Alcoholic cirrhosis was replaced by hepatitis non-A, non-B, or C as the most common reason for LTX. The proportions of recipients with fulminant liver failure and malignancies, indications for poorest survival, declined significantly in 1993. The cumulative probability of surviving for 6 years after initial transplantation was 0.70 (without retransplantation = 0.58) for pediatric recipients.(ABSTRACT TRUNCATED AT 400 WORDS)

Trends in liver transplantation in the United States.

Although the growth in liver transplantations (LTX) recorded by the Pitt-UNOS Liver Transplant Registry since October 1987 continues, the rate of increase has been declining in recent years. Among children, the number of procedures reached a peak in 1990 and declined each year thereafter. The number of centers performing LTX continued to increase. However, in 1992, compared with previous years, the greatest proportion of centers had a decreased volume of procedures, and the fewest number of new centers were opened. Upon examining characteristics of pediatric recipients from 1987 through 1992, no significant trends were noted for sex, race, age, or nationality. The distribution of functional status in 1992 was similar to that prior to 1991. Compared with recipients in the other 2 time periods, recipients in 1991 were more likely to be in the best functional status and least likely to be in the ICU. The most common indication for LTX in children was biliary atresia, though the proportion of recipients with this primary liver disease decreased significantly over the study period. Significant increases were noted in the proportions of pediatric recipients with autoimmune disease (though this remains a relatively uncommon indication) and fulminant liver failure. There have been trends in many of the characteristics examined for adult recipients. The proportion of male recipients grew significantly between 1987 and 1992. Decreasing proportions of White recipients and increases among Hispanics and Asians were found. The mean and median ages of adult recipients peaked in 1990, with a slight decrease in 1992 reflecting a slight rise in the proportion of the youngest age group and a slight decline for the oldest age group. Adult recipients had better functional status in 1991 than earlier recipients, and the distribution in 1992 was very similar to that in 1991. The trend in the proportion of recipients with positive CMV serology followed very closely the pattern in age distribution, peaking in 1991 and dropping slightly in 1992. The proportions of multiorgan recipients were similar in all 3 time periods. However, in 1992, contrasting with previous years, most multiorgan procedures involved only a kidney. Alcoholic cirrhosis continued to be the most common reason for LTX, though the combination of non-A, non-B hepatitis and hepatitis C accounted for only 20 fewer recipients. The proportions of recipients with hepatitis B and malignancies (the indications with the poorest survival) declined significantly. The cumulative probability of patient (retransplantation-free) survival 5 years after initial transplantation was 0.7 (0.58) for pediatric recipients.(ABSTRACT TRUNCATED AT 400 WORDS)

The Pitt-UNOS Liver Transplant Registry.

Since the establishment of the scientific LTR, the frequency of OLTX has been increasing. Between 1988 and 1991, the number of procedures performed on pediatric patients increased by 28.2%, and among adult patients OLTX increased 84.8%. During this same period, the number of transplant centers performing OLTX rose 62.5% for children, and 54.7% for adult recipients. In 1991 there was a larger proportion of recipients under 1 year of age than in previous years. The effect was to lower the median age at transplantation from over 2 to between 1 and 2. In pediatric recipients of initial transplantation in 1991, compared with earlier recipients, the functional status at time of liver transplantation was improved. Fewer children were in the ICU while awaiting transplantation, and more were able to wait at home. Multiorgan transplantations in pediatric patients remained relatively rare, but a larger portion of these procedures in 1991 than was seen previously included the small intestine. Biliary atresia remained the most common indication for liver transplantation among children, accounting for over 55% of all OLTX procedures in 1991. There was a significant change in the racial distribution among adult recipients. Compared with previous years, there were greater proportions of Hispanic and Asian recipients in 1991. Adult recipients were older in 1991 than previously, and the median age increased from 46 to 49. As with pediatric recipients, adult recipients had better functional status in 1991 than earlier recipients. The increase in positive CMV serology was likely to be a function of older age. Among multiorgan recipients, the combination of liver and pancreas only was much less common in 1991 than previously. As was found previously (1), alcoholic cirrhosis continued to be the most common reason for OLTX, with the proportion of patients diagnosed with this condition increasing in 1991. Twice as many patients with cystic fibrosis were recipients in 1991 as in the prior 3 years. There were decreases in the proportion of patients receiving OLTX due to fulminant liver failure, metabolic disease, and malignant neoplasms. The cumulative probability of surviving (without retransplantation) 4 years after initial transplantation was 0.74 (0.61) for pediatric recipients. Univariate (unadjusted) analyses detected significant differences in survival for age (the youngest recipients had the worst survival), UNOS description (poorer functional status just prior to transplantation led to poorer survival), and primary liver disease (survival was worst for recipients transplanted due to fulminant liver failure, and best for patients with alpha-1 antitrypsin deficiency).(ABSTRACT TRUNCATED AT 400 WORDS)

Liver transplantation in the United States: 1988 to 1990.

Between 1988 and 1990, the frequency of liver transplantation in the United States increased by 57%. During this same period, the number of transplant centers performing this procedure increased from 58 to 80. Despite this increase, only 15 centers reported a total of at least 100 procedures during these 3 years, compared to 25 centers that performed 12 or less liver transplantations. Recipient characteristics have been changing over time: a larger proportion of recipients were males in 1990 than in 1988 or 1989. The distribution of recipients changed dramatically; the median age increased by 4 years, due to an increased proportion of transplantations among those age 40 and older and a decrease in children younger then age 10. Another major change was in functional status; in 1988 and 1989, over half of the recipients were hospitalized while awaiting transplantation, but this was reversed in 1990, when the majority of patients was at home awaiting transplantation. Furthermore, the proportion of patients in the highest functional class more than tripled. Alcoholic liver disease, which in 1989 became the most common primary liver disease of patients undergoing liver transplantation, continues to be the indication for an increasing number of recipients. The proportion of recipients with biliary atresia and primary biliary cirrhosis, the most common diagnoses in 1988, continues to decrease. Most of the mortality was noted in the first 6 months, when overall cumulative patient mortality was about 20%, half of which occurred in the first 4 weeks after OLTX. The cumulative 3-year posttransplant survival rate was 67%. Similarly, cumulative retransplant-free survival rates were 84% at 1 month and 58% at 3 years. As previously described (1), recipient factors associated with survival included age, UNOS description, diagnosis, and ABO matching. Older recipients, those with poorer functional status at time of transplantation, recipients with either fulminant liver failure or malignancies, and those who received a graft from an ABO-compatible or -incompatible donor, had the worst survival rates. Furthermore, in the current analysis we found that the outcome of recipients was affected adversely by grafts from female donors. Racial differences were noted, but the large quantity of missing data precluded definitive statements regarding any association with survival. Both recipient and donor ages were significant prognostic factors. For adults in the multivariate model, increasing recipient age was associated with higher mortality. Among children, however, younger donor age seemed to have an adverse effect on recipient survival. Donor characteristics also changed during this period.(ABSTRACT TRUNCATED AT 400 WORDS)

Liver transplantation in the United States: 1988 to 1989.

Orthotopic liver transplantation was performed more often in 1989 than in 1988. This procedure was performed at 57 institutions in 1988 and at 64 in 1989. Among the 53 institutions in which OLTX was performed in both years, the tendency was to increase volume. Volume in 1988 was not an indicator for volume increase or decrease in the next year. For example, about 60% of the centers which performed 5-9 OLTXs in 1988 had a greater volume in 1989. This was similar to the percentage among centers which performed 30-49 OLTXs in 1988. Only centers which performed at least 100 OLTXs in 1988 increased in volume uniformly (3 centers). There was about a 25% increase in the number of OLTX recipients, and the characteristics of the recipient population changed. In 1989, as compared to 1988, there was a larger proportion of recipients over age 40 with a concomitant proportionate decrease in pediatric recipients. Indications for OLTX were also different. In 1988, biliary atresia and primary biliary cirrhosis were the major diagnoses for which OLTX was performed. In 1989, however, alcoholic cirrhosis was the most prevalent diagnosis among OLTX recipients, accounting for more than 1 of every 7 procedures. We also found that the distribution of UNOS description changed. Significantly more recipients were classified in the best functional group, and significantly more recipients were on life support in 1989 compared to 1988. Whether this reflects a change in the actual functional status of recipients, or change in the management of these patients, is a topic for further research.(ABSTRACT TRUNCATED AT 250 WORDS)

Pitt-UNOS Liver Transplant Registry.

The Pitt-UNOS Liver Transplant Registry maintains a computerized database of all orthotopic liver transplantations (OLTX) performed in the United States since October 1, 1987. Recipient data, which are collected at the time of transplantation and at specified follow-up time periods, are reported to the Registry directly, while donor data are transmitted through UNOS Central. During the first year of registration (October 1, 1987 through September 30, 1988), 1,561 liver transplantations were performed on 1,377 patients; 146 patients received 2 livers and another 19 patients received 3 livers. There were 29 multiorgan transplants, including 18 liver/kidney, 7 liver/pancreas, 1 liver/small bowel, 2 liver/kidney/heart, and 1 liver/kidney/pancreas. Among the 52 centers reporting at least 1 liver transplant during this time period, 34 (65%) performed less than 20 procedures and only 7 (13%) performed at least 50 transplantations. Sixty-three percent of the donors were male; 63% were less than 25 years of age and in 72% the cause of death was motor vehicle accidents, gunshot wounds, or cerebrovascular accidents. Recipients were older than donors, 37% above age 45. About 25% of the recipients required intensive care or life support. The majority suffered from cirrhosis of cholestatic, autoimmune, viral, alcoholic, or unspecified etiology. The 6-month cumulative survival following OLTX was 76%, and the 6-month retransplant-free survival rate was 69%. Survival rates at 1 year were 72% and 64%, respectively. Factors associated with patient survival were diagnosis of liver disease and work (UNOS) status. Patients with fulminant liver failure or malignancies had the poorest survival, and patients with cholestatic cirrhosis or other cirrhosis had the best.(ABSTRACT TRUNCATED AT 250 WORDS)