Rapid identification of cytomegalovirus in liver allograft biopsies by in situ hybridization.

Identifying the etiology of hepatic dysfunction in liver transplant patients is critical to their clinical management and in maintaining graft survival. While cytomegalovirus (CMV) is a well-known cause of posttransplant hepatitis, the morphologic diagnosis of CMV hepatitis in liver biopsies can be difficult. Because conventional tissue culture for CMV requires days to weeks, the final results often arrive too late to be clinically useful. In this study, 44 liver allograft biopsies from 21 patients with hepatic dysfunction were evaluated for CMV by routine light microscopy, conventional tissue culture, and in situ DNA hybridization (IH) using commercially available biotinylated CMV-specific DNA probes. Whereas 38.6% of the biopsy specimens were positive by IH, 15.9% were culture-positive biopsies and 13.6% were positive by routine light microscopy. Assuming tissue culture to be the standard, IH demonstrated a sensitivity of 100% and a specificity of 73%. In comparison, routine light microscopy showed a sensitivity of 71.4% and specificity of 97.3%. In addition, three biopsy specimens positive only by IH were from three patients who had other liver biopsies positive for CMV by either light microscopy or viral culture. In situ DNA hybridization allows rapid detection (5-6 h) of CMV in paraffin-embedded liver allograft biopsies; it also has a sensitivity that surpasses routine histologic examination and perhaps even tissue culture.

Primary nonfunction. Is there a contribution from the back table bath?

A persistent problem in orthotopic liver transplantation (OLT) is primary nonfunction (PNF) of the hepatic allograft. In most instances the cause of the failure is unknown. In an attempt to minimize these graft failure, modifications in the procurement and operative procedure have been investigated. One change in the procedure at the University of Nebraska Medical Center has been the monitoring of the temperature of the fluid in the back table bath during preparation of the donor liver. Our initial procedure involved creating an ice slurry of lactated Ringer's solution and ice slush in which the donor liver was then prepared. The temperature of this ice slurry was retrospectively found to be from -3 degrees C to -1 degrees C (group I). In this group there was a higher-than-expected incidence of PNF. To investigate whether the temperature of the back table bath influenced the incidence of PNF, beginning with transplant No. 42 the preparation of the back table bath was modified. The bath was created by adding a small amount of PlasmaLyte slush to 2 L of PlasmaLyte (group II). The temperature of the bath was maintained at 2-4 degrees C. Data were collected on 100 consecutive liver transplants. All transplants were performed using standard techniques, the operation for the two groups differing only as described above. Transaminase levels were followed as an index of the allograft function and were expected to begin to normalize within 2-3 days after transplantation. While both groups display this trend, transaminase levels in group II were significantly lower postoperatively than group I levels (P less than 0.05). Preoperative values were similar. There were 7 PNFs in group I; 0 in group II (P less than 0.005). We feel that the change in the back table procedure has positively influenced the function of the hepatic allografts, and we conclude that transplant centers need to monitor the temperature at which all allografts are stored and prepared, and the cognizant that this may influence the postoperative function of the transplanted liver.

The spectrum of Pneumocystis carinii infection after liver transplantation in children.

We report the experience with Pneumocystis carinii lung infections in the 109 children undergoing liver transplantation at our hospital between August, 1985 and May, 1989. PCP developed in 9 of the 86 patients (10%) surviving > or = 6 weeks after transplantation and not receiving P carinii chemoprophylaxis. Of the 59 patients undergoing BAL 2 or more weeks after transplantation there were 16 specimens from 14 patients (24%) positive for P carinii. These patients had a spectrum of illness ranging from asymptomatic to severe pneumonia requiring mechanical ventilation. The mean interval from first transplantation to bronchoalveolar lavage positive for P carinii was 24.9 weeks and the mean interval to first PCP was 28.0 weeks. The earliest and latest occurrences of PCP were 7 weeks and 73 weeks, respectively, after transplantation. There were no complications attributed to BAL.

Procurement and preparation of human isolated small intestinal grafts for transplantation.

We have developed a donor operation that incorporates en bloc removal of the liver and intestine with a limited surgical resection in vivo. Over the past 18 months, we have used the following technique for the retrieval and preparation of seven isolated small intestinal allografts. The donor operation and bench preparation can be divided into three phases. During the first phase, the small intestine is removed with the liver, pancreas, and an aortic segment. In the second phase performed ex vivo, the donor liver can be separated from the specimen. The third phase involves additional bench dissection to yield an isolated intestinal allograft. The principle advantage of this technique is that it reduces potential liver injury by minimizing the surgical dissection required in vivo. Also, dividing the liver from the intestine ex vivo allows the organs to be separated in a bloodless field under controlled conditions that may be especially important when two different surgical teams are involved.

Clinical presentation of hepatic artery thrombosis after liver transplantation in the cyclosporine era.

Hepatic artery thrombosis is a dreadful complication of orthotopic liver transplantation. It should be suspected in cases of fulminant liver failure, delayed bile leak, or intermittent sepsis of unknown cause after liver transplantation. Accurate diagnosis is assisted by ultrasound and computerized tomography scans, but usually requires arteriography. Prompt retransplantation is required in most of the cases.

Pontine and extrapontine myelinolysis following liver transplantation. Relationship to serum sodium.

The relationship between central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) and serum sodium changes in the setting of orthotopic liver transplantation (OLT) is examined. Postmortem examination of 14 patients with end-stage liver disease who underwent liver transplantation revealed CPM in four, of which three also had EPM. A retrospective review of clinical and laboratory data was performed on all patients. There were marked perioperative rises (21-32 mEq/L) in the serum sodium concentration in all four patients who developed myelinolysis. In contrast, the largest increase in sodium in patients without demyelination was 16 mEq/L. We conclude that perioperative rises in the serum sodium concentration increase the risk of myelinolysis. CPM and EPM should be considered if the patient develops mental status changes or focal neurological deficits several days after OLT.

A new technique for combined liver/small intestinal transplantation.

The most common application of small bowel transplantation is for the patient with parenteral nutrition-induced liver failure. In this setting, the small intestine is transplanted simultaneously with the liver. We identified three technical problems that we believe contributed to complications in our first eight patients. First, pancreaticoduodenectomy was challenging in the infant donor. Second, the bowel graft was prone to volvulus around the skeletonized donor portal vein. Third, in the pediatric recipient, use of the donor bowel for Roux-en-Y biliary reconstruction was associated with biliary leaks in the early postoperative period. Our surgical technique of liver/small bowel (L/SB) transplantation has evolved since our early experience in 1990. Modifications in the L/SB operation, reported briefly in 1996 and 1997, have led to easier graft preparation and have reduced the incidence of technical complications.

Successful small bowel allotransplantation in dogs with cyclosporine and prednisone.

Twelve dogs had transplantation of almost the entire small intestine in the orthotopic location; immunosuppression was with cyclosporine and prednisone. Half the dogs had survival of at least one month, and a third lived for at least four months. Two of the animals are still living after 550 and 555 days. Maintenance of nutrition, and absorption of D-xylose and fat were better than in control animals with an iatrogenic short gut syndrome, but distinctly worse than that of normal dogs.

Frozen section evaluation of donor livers before transplantation.

Frozen section examination was performed on 385 donor livers before transplantation. Exclusion criteria were applied to the donor livers examined to exclude potentially dysfunctional livers. The exclusion criteria included the following: severe macrovesicular steatosis, ischemic necrosis, prominent chronic portal inflammation, prominent periductular fibrosis, granulomatous inflammation, bridging fibrosis, and malignancy. Twenty-seven of the 385 donor livers examined were excluded before transplantation. The following histologic features were present in the excluded livers: severe steatosis (22), ischemic necrosis (2), portal inflammation (1), and periductular fibrosis (2). Steatosis was present in 51 of the 385 (13.25%) organs examined, including 22 of the donor organs excluded before transplantation. Twenty-nine livers with mild to moderate steatosis were implanted into size and blood type-matched recipients. Indicators of allograft function (prothrombin time and bilirubin) and damage (aspartate aminotransferase and alanine aminotransferase) were measured daily for the first 10 days after transplant. There was no statistically significant difference between the group of nonfat livers and donor livers containing mild steatosis. Statistically significant higher posttransplant serum alanine aminotransferase and prothrombin time levels were present in the patients with livers implanted with mild versus moderate steatosis. The 1-year survival rate for patients receiving fatty versus nonfatty donor livers was not statistically different (Kaplan-Meier, P = 0.592). No significant differences were found in the clinical and laboratory characteristics of donors whose organs were implanted compared with the clinical and laboratory characteristics of donors whose organs were excluded. The primary nonfunction rate after applying the exclusion criteria was 1.4%, which is a significant decrease compared with our primary nonfunction rate of 8.5% before using frozen section examination. Frozen section examination is useful in excluding donor organs which may become dysfunctional after transplantation.

Long-term use of cyclosporine in liver recipients. Reduction of dosages in the first year to avoid nephrotoxicity.

Cyclosporine is a potent immunosuppressive drug, which has dose-related nephrotoxicity. In renal transplantation, the differentiation between rejection and toxicity is difficult and even with the aid of blood levels of the drug, it may be difficult to establish a chronic maintenance dose. Long-term survivors after liver transplantation can provide modes with which to establish maintenance doses, as these are dictated by nephrotoxicity in these patients. Twenty-nine liver transplant patients who survived one year or more were followed for changes in their cyclosporine doses. Daily oral cyclosporine dose, BUN, serum creatinine and bilirubin were monitored. The reductions in cyclosporine were dictated almost entirely by the findings of nephrotoxicity.

The impact of immunosuppressive regimens on the cost of liver transplantation--results from the U.S. FK506 multicenter trial.

In an effort to determine the total one-year cost of liver transplantation, the underlying drivers of that cost, and any cost differences between alternative immunosuppressive regimens, an analysis was performed comparing the average one-year posttransplant charges of 322 patients participating in the "U.S. Multi-center Prospective Randomized Trial Comparing FK-506 to Cyclosporine in Liver Transplantation." Total one-year inpatient charges including all readmissions were examined. Professional fees and outpatient charges were excluded. Costs for tacrolimus drug and blood assays were assumed to be equal to those in the CsA group. For patients completing the study, the tacrolimus group had an average length of stay and average one-year cost seven days (P = .06) and $19,290 (P = .05) lower than the CsA group. The difference in rejection profiles between the two arms seems to largely account for the lower costs. The tacrolimus arm consistently had fewer patients in the more severe rejection groups. Increased incidence and severity of rejection were directly related to higher average lengths of stay and costs of transplantation (P < .001). Tacrolimus immunosuppression during the first year after liver transplantation is more cost-effective than CsA in achieving similar patient and graft survival rates. Differing incidence and severity of rejection can dramatically affect the first-year cost of liver transplantation.

Hepatic allograft rescue following arterial thrombosis. Role of urgent revascularization.

Hepatic artery thrombosis is a continuing source of morbidity and mortality following orthotopic liver transplantation. The cornerstone of therapy has been urgent retransplantation that is limited by organ availability. For this reason we developed a policy of urgent revascularization for allograft rescue. Hepatic artery thrombosis developed following 15 transplants of which 11 underwent urgent rearterialization. The diagnosis was made a mean of 4.8 days (range 1-10) following transplantation. Duplex ultrasonography was diagnostic in all patients and confirmed by angiography in 4 (36%). Three patients with hepatic artery thrombosis were identified following screening ultrasonography and were clinically unsuspected. Upon reexploration, a specific technical reason for hepatic artery was found in 4 patients (36%). Twelve arterial revascularization procedures were performed in 11 patients including: thrombectomy alone (n = 4); revision of anastomosis with thrombectomy (n = 5); and thrombectomy with placement of vascular conduit (n = 3). Following revascularization, 8 patients maintained hepatic artery patency. Three patients eventually required retransplantation secondary to biliary sepsis. Biliary tract complications developed in 6 patients, at a mean of 23 days following revascularization and included: breakdown of the biliary anastomosis (n = 4); stricture (n = 1); and sludge formation (n = 1). The overall graft and patient survival are 74% and 82% respectively, with a mean follow-up of 6.8 months. Hepatic allograft rescue with the use of urgent revascularization following hepatic artery thrombosis appears to be an effective means of either avoiding retransplantation or providing a bridge until a suitable donor becomes available.

Transfusion-induced graft-versus-host disease after liver transplantation. Documentation using polymerase chain reaction with HLA-DR sequence-specific primers.

Graft-versus-host disease (GVHD) occurring after liver transplantation can pose a difficult diagnostic dilemma. Similar clinical and pathologic skin and gastrointestinal manifestations can result from other causes (i.e., drugs, infections). Treatment for each of these entities differs, and the high mortality associated with GVHD makes this distinction critical. GVHD has been assumed to result from the cotransplantation of donor lymphoid tissue along with the allograft. In most instances, the patient also receives blood products during the operation, and occasionally during the postoperative period, and the lymphoid cells in these products are also a potential source of concern. In this report, we describe a patient who developed GVHD after liver transplantation. Using molecular diagnostic techniques, we determined that the source for this GVHD was not the organ donor, but was most likely nonirradiated blood products received during the hospital course. Our results suggest that transplant recipients with concomitant hematopoietic dysfunction would benefit from irradiated blood products to reduce the likelihood of this complication.

Combined liver/small bowel transplantation using a blood group compatible but nonidentical donor.

A successful liver/small intestinal transplantation with a blood group O donor to a blood type A recipient is described. Mild graft versus host disease developed, manifested by hemolysis, but did not result in graft loss or patient mortality. This suggests that minor ABO incompatibility may be tolerated with intestinal transplantation, despite the transplantation of large amounts of lymphoid tissue.

The results of reduced-size liver transplantation, including split livers, in patients with end-stage liver disease.

We initiated a policy of using RSLT in critically ill patients in June of 1988. Since that time we have performed 30 RSLTs in 29 patients, including 28 children and 1 adult. The mean age of the children was 27 months (range 1 month to 10 years) with 14 (52%) being 1 year of age or less. The mean weight was 11.3 kg (range 2-50 kg) with 20 being 10 kg or less. A total of 22 patients were in the intensive care unit at the time of RSLT including 9 who were intubated. Of the 30 RSLTs, 23 were performed as a primary transplant while 7 were retransplants. Indications for primary transplantation included biliary atresia (n = 11), fulminant hepatic failure (n = 5), neonatal hepatitis (n = 4) and others (n = 3). The RSLT was used in retransplantation for primary nonfunction (n = 2), hepatic artery thrombosis (n = 2), chronic rejection (n = 2), and herpetic hepatitis (n = 1). The size reductions included 18 left lobes, 7 left lateral segments, and 5 right lobes. This group includes the use of the split-liver technique, which was applied to 10 patients (5 livers). The median donor/recipient weight ratio for left lobe transplants was 2:1; left lateral segments was 7.3:1; and right lobes 1.6:1. One year actuarial patient and graft survivals were 68 and 65%, respectively, with a mean follow-up of 10.6 months. The number of children dying awaiting transplantation has been significantly reduced following the introduction of RSLD (3 of 115, 2.6% vs. 12 of 95, 13%; P less than 0.02).

Extracorporeal liver perfusion using human and pig livers for acute liver failure.

BACKGROUND: Patients with fulminant hepatic failure (FHF) often die awaiting liver transplantation. Extracorporeal liver perfusion (ECLP) has been proposed as a method of "bridging" such patients to transplantation. We report the largest experience to date of ECLP using human and porcine livers in patients with acute liver failure. METHODS: Patients with FHF unlikely to survive without liver transplantation were identified. ECLP was performed with human or porcine livers. Patients underwent continuous perfusion until liver transplantation or withdrawal of support. Two perfusion circuits were used: direct perfusion of patient blood through the extracorporeal liver and indirect perfusion with a plasma filter between the patient and the liver. FINDINGS: Fourteen patients were treated with 16 livers in 18 perfusion circuits. Nine patients were successfully "bridged" to transplantation. ECLP stabilized intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Arterial ammonia levels fell from a median of 146 to 83 micromol/liter within 12 hr and this reduction was maintained at least 48 hr. Pig and human ECLP lowered ammonia levels equally. Serum bilirubin levels also fell from a median of 385 to 198 micromol/liter over the first 12 hr but the response was not sustained as well with porcine livers. There was no immunological benefit to using the the filtered perfusion circuit. INTERPRETATION: These data demonstrate that ECLP is safe and can provide metabolic support for comatose patients with fulminant hepatic failure for up to 5 days. While labor and resource intensive, this technology is available to centers caring for patients with acute liver failure and deserves wider evaluation and application.

Disaccharidase activities and fat assimilation in pediatric patients after intestinal transplantation.

BACKGROUND: Intestinal transplantation has become an accepted therapy for short bowel syndrome and other types of intestinal failure. In order to assess digestive capabilities and feeding practices in a group of 22 pediatric patients after intestinal transplantation, we assessed mucosal disaccharidase activities and assimilation of total dietary lipid and vitamin E. Twelve of the patients had undergone contemporaneous liver transplantation. METHODS: Mucosal biopsies were assayed for disaccharidase activities between 15 and 412 days after transplantation in 7 of the 22 when all were receiving some enteral nutrition and were free of rejection. Coefficients of lipid absorption were determined in those patients receiving total enteral feeding (two-thirds polymeric/one-third elemental) between 43 and 1032 days after transplantation; oral vitamin E tolerance tests were done at about the same time. RESULTS: Activities of lactase, sucrase, maltase, and palatinase consistently exceeded reference ranges (P<0.05). Mean coefficient of lipid absorption equaled 86+/-12% and was not influenced by duration of time after transplantation. No patient required dietary lipid restriction. No significant absorption of vitamin E was demonstrated until 160 days after transplantation. Vitamin E absorption did correlate with length of time elapsed after surgery (r=0.64, P<0.0011). CONCLUSIONS: The results of this investigation show that, in the absence of histologic or clinical indications of allograft rejection, pediatric intestinal transplant recipients do not have primary disaccharidase deficiencies. Similarly, absorption of usual dietary lipid content is adequate once weaning from parenteral nutrition is complete. In contrast, early assimilation of vitamin E is poor. Vitamin E absorption subsequently improves, but the mechanism is obscure.

Lack of utility of intestinal fatty acid binding protein levels in predicting intestinal allograft rejection.

INTRODUCTION: The enterocyte-specific protein, intestinal fatty acid binding protein (I-FABP), is detectable in serum only after intestinal injury. Previous studies in animals suggest that I-FABP might be a useful marker of intestinal allograft rejection. MATERIALS AND METHODS: I-FABP was repetitively measured in nine intestinal transplant recipients and correlated with findings of surveillance endoscopy. RESULTS: Average interval between I-FABP determination and biopsy was 3.4 days (SD=4.2 days). Average number of rejection episodes per patient totalled 1.6+/-1.2. General linear modeling demonstrated no tendency for increases in serum FABP to precede histologic graft rejection (P=0.263). Restriction of the analysis to I-FABP determinations 1 day before or on the day of biopsy failed to affect these results. Minor increases in I-FABP were often associated with histologically normal grafts, whereas rejection often occurred when I-FABP was not detectable. DISCUSSION: Serum I-FABP levels do not predict clinical intestinal allograft rejection.

Efficacy of tacrolimus as rescue therapy for chronic rejection in orthotopic liver transplantation: a report of the U.S. Multicenter Liver Study Group.

BACKGROUND: A study was performed by 17 different U.S. liver transplantation centers to determine the safety and efficacy of conversion from cyclosporine to tacrolimus for chronic allograft rejection. METHODS: Ninety-one patients were converted to tacrolimus a mean of 319 days after liver transplantation. The indication for conversion was ongoing chronic rejection confirmed by biochemical and histologic criteria. Patients were followed for a mean of 251 days until the end of the study. RESULTS: Sixty-four patients (70.3%) were alive with their initial hepatic allograft at the conclusion of the study period and were defined as the responder group. Twenty-seven patients (29.7%) failed to respond to treatment, and 20 of them required a second liver graft. The actuarial graft survival for the total patient group was 69.9% and 48.5% at 1 and 2 years, respectively. The actuarial patient survival at 1 and 2 years was 84.4% and 81.2%, respectively. Two significant positive prognostic factors were identified. Patients with a total bilirubin of < or = 10 mg/dl at the time of conversion had a significantly better graft and patient survival than patients converted with a total bilirubin > 10 mg/dl (P=0.00002 and P=0.00125, respectively). The time between liver transplantation and conversion also affected graft and patient survival. Patients converted to tacrolimus < or = 90 days after transplantation had a 1-year actuarial graft and patient survival of 51.9% and 65.9%, respectively, compared with 73.2% and 87.7% for those converted > 90 days after transplantation. The mean total bilirubin level for the responder group was 7.1 mg/dl at the time of conversion and decreased significantly to a mean of 3.4 mg/dl at the end of the study (P=0.0018). Thirteen patients (14.3%) died during the study. Sepsis was the major contributing cause of death in most of these patients. CONCLUSIONS: Our results suggest that conversion to tacrolimus for chronic rejection after orthotopic liver transplantation represents an effective therapeutic option. Conversion to tacrolimus before development of elevated total bilirubin levels showed a significant impact on long-term outcome.

Orthotopic liver transplantation in children: two-year experience with 47 patients.

During a 24-month period (May 1981 to May 1983), 47 pediatric patients (ranging in age from 7 months to 18 years) underwent orthotopic liver transplantation using cyclosporine and prednisone. Major indications were biliary atresia/hypoplasia, and metabolic liver disease. Thirty-two of 138 patients evaluated for the procedure died prior to transplantation. Thirty patients are alive from 6 to 29 months later including 7/15 patients who required retransplantation. Twenty-one of 32 patients are alive at 1 year following initial transplantation. All 30 survivors are clinically well and living at home; only one has an abnormal bilirubin level. Serious, life-threatening medical and surgical complications were common during the early months following transplantation. With one exception, deaths and major rejection episodes occurred early (before 120 days). All survivors are relieved of the stigmata of chronic liver disease, and many have demonstrated catch-up growth. Liver transplantation is an effective treatment for end-stage pediatric liver disease.