No protective function found in Wistar rats submitted to long ischemia time and reperfusion after intermittent clamping of the total hepatic pedicle.

BACKGROUND: Although the intermittent Pringle maneuver is used for major transplant surgery, traumas, and hepatic protection, long ischemia time and reperfusion may limit some protection in Wistar rats. The aim of the study was to evaluate the protection effects of intermittent clamping in the total hepatic pedicle after a long period of ischemia and reperfusion in Wistar rats. METHODS: Forty-two male Wistar rats, weighing ± 327.7 g, were anesthetized intravenously with sodium thiopental and given a U-shaped incision in the abdomen. The total hepatic pedicle was isolated and subjected to clamping with a microvascular clamp. Groups included were the continuous group (CG, n = 14, 40 minutes of ischemia/40 minutes of reperfusion); the intermittent group (IG, n = 14, 4 cycles a 10 minute ischemia/reperfusion 10 minutes); and the sham group (SG, n = 14, 80 minutes of observation time). Blood collection for transaminase dosage was carried out, and hepatic biopsy specimens were taken for mitochondrial respiration and histological evaluation. RESULTS: In groups CG and IG, aspartate aminotransferase and alanine aminotransferase enzymes were elevated in comparison to group SG (P < .008); mitochondrias, when stimulated by use of adenosine diphosphate or carbonylcyanide p-trifluoromethoxyphenylhydrazone, had a significant decrease in mitochondrial respiration (P < .05), and the respiratory control ratio in the ischemic groups was lower (P < .03) when compared with the GS. On histological examination, 100% of the GC had lesions: 33% focal hemorrhagic necrosis, 17% sinuzoidal congestion and/or vacuolization, and 50% venous congestion; in the IG, 100% had lesions: 43% sinusoidal congestion and/or vacuolization and 57% venous congestion. CONCLUSIONS: The intermittent total hepatic pedicle clamping for a long period of time in the Wistar rats had no efficacy in protection of liver injury.

Red blood cell antigen alloimmunization in liver transplant recipients.

Orthotopic liver transplantation (OLT) is a life-saving procedure for patients with end-stage liver disease. Transfusion support is an important part of OLT. Intraoperative transfusion of large volumes of blood products is recognized to be a poor prognostic factor, probably due to the negative effects of blood transfusions, such as transfusion reactions, infectious contamination of blood products, or immune modulation of the transfused patient. The aim of this study was to evaluate the frequency of alloimmunization and its specificity to red blood cell (RBC) antigens among patients undergoing OLT. We identified 74 RBC alloantibodies in 70 (23%) patients when the indirect antiglobulin test (IAT) was performed. The most common RBC alloantibodies were against Rh system antigens. The majority (41.9%) were directed against the E antigen. Despite the ethnic heterogeneity of our population there were no cases of intravascular hemolysis. The incidence of alloimmunization (23%) was slightly higher among patients than in the literature, most probably as a consequence of our ethnic heterogeneity.

Prospective analysis between the therapy of immunosuppressive medication and allogeneic microchimerism after liver transplantation.

After liver transplantation, migration of donor-derived hematopoietic cells to recipient can be detected in peripheral blood. This state is termed microchimerism. The aim of this study was to investigate prospectively the presence of allogeneic microchimerism, the occurrence of acute cellular rejection and the level of immunosuppression in transplanted patients. Microchimerism occurrence between 10 days and 12 months after liver transplantation was analyzed in 47 patients aged between 15 and 65 by a two-stage nested PCR/SSP technique to detect donor MHC HLA-DR gene specifically. A pre-transplant blood sample was collected from each patient to serve as individual negative control. Microchimerism was demonstrated in 32 (68%) of the 47 patients; of these, only 10 patients (31.2%) presented rejection. Early microchimerism was observed in 25 patients (78.12%) and late microchimerism in 7 patients (21.8%). Among the patients with microchimerism, 14 were given CyA and 18 were given FK506. In the group without microchimerism, 12 patients were given CyA and 03 were given FK506. There was a significant association between the presence of microchimerism and the absence of rejection (p=0.02) and also between microchimerism and the type of immunosuppression used. Our data indicate that microchimerism and probably differentiation of donor-derived leukocytes can have relevant immunologic effects both in terms of sensitization of recipient and in terms of immunomodulation toward tolerance induction.

Extragastrointestinal stromal tumor and liver transplantation: case report and review.

The occurrence of de novo malignant neoplasias has been shown in postransplant patients under imunosuppression. It is the second leading cause of late death in liver transplant recipients. The greatest incidence is seen in cancers associated with chronic infection by human papilloma virus, skin cancers, oropharyngeal, and gastrointestinal (GI) malignancies. GI stromal tumors (GISTs) are the most common mesenchymal tumors of the GI tract. Rare cases are identified outside the GI tract are collectively known as extragastrointestinal stromal tumors (EGISTs). We present an EGIST case in a liver transplantation patient. A 64-year-old man underwent liver transplantation because of cirrhosis (hepatitis B virus and alcoholism) and hepatocellular carcinoma. Histopathologic findings revealed 2 trabecular hepatocellular carcinomas: a 3.5-cm-diameter lesion located at segment VIII and another 2-cm one at segment V. Seven months later, he noticed a hardened, mobile, painless, 3-cm subcutaneous nodule in the perineum localized in the right lateral quadrant 2 cm distant from the anus. A surgical resection with 1 cm margin yielded a histopathology report of a 5.0 x 3.0 cm spindle cell stromal tumor. The immunohistochemical profile was compatible with a GIST, with 5 mitosis per 50 high-powered fields. This tumor is extremely rare after liver transplantation but has shown a good outcome up to now.

Expanded Milan criteria on pathological examination after liver transplantation: analysis of preoperative data.

BACKGROUND: We sought to evaluate the accuracy of imaging techniques related to the Milan criteria (MC) compared with the explant histology and the survival of these patients. METHODS: Between 1997 and 2006, we selected 45 cirrhotic patients with hepatocellular carcinoma distributed into two groups according to explant histology: MC and Expanded Milan Criteria (EMC). Age, gender, preoperative imaging (ultrasound [US] and/or computed tomography [CT]), maximal tumor dimension, number of tumors, explanted histology, histology degree, alpha-fetoprotein (AFP) level and vascular invasion were compared among the patients to evaluate the value of these prognostic factors for survival after liver transplantation. RESULTS: By histology 42.2% explants were identified as EMC. The mean AFP level was 204.5 ng/mL. Vascular invasion was detected in 31.5% of explants and 68.4% showed incidental tumors. The survival rates after 10 years were 47.4% whereas MC patients showed 57.77%. The mean AFP level among MC patients was 150.2 ng/mL with vascular invasion detected in 7.7% of explants, and 47.4% with incidental tumors. The overall sensitivity of the imaging techniques was 83.3% for CT and 75% for US. The specificity was 96% for CT and 80.1% for US. CONCLUSION: Scan examinations in the preoperative evaluation underestimated about 42.2% of tumors. Those patients had vascular invasion but the survival after 10 years was similar between the ECM and MC groups.

Intraoperative massive transfusion decreases survival after liver transplantation.

Patients undergoing liver transplantation often experience coagulopathy and massive intraoperative blood loss that can lead to morbidity and reduced survival. The aim of this study was to verify the survival rate and discover predictive factors for death among liver transplant patients who received massive intraoperative blood transfusions. This cohort study was based on prospective data collected retrospectively from January 2004 to July 2006. The 232 patients were distributed according to their blood requirements, (namely, more or less than 6 units), including red blood cell saver. The statistical analyses were performed using Student t test, Cox hazard regression, and the Kaplan-Meier method (log-rank test). The massively transfused cohort displayed higher Child-Pugh classifications (10.2 vs 9.6; P = .03); model for end-stage liver disease (MELD) scores (19 vs 17; P = .02); recipient weights (75.4 vs 71 kg; P = .03); as well as warm ischemia times (70.7 vs 56.4 minutes; P < .001) and surgery times (584.6 vs 503.4 minutes; P < .05). The proportional hazard (Cox) regression analysis showed that the risk of death increased 2.1% for each unit of donor sodium and 1.6% for each additional year of donors age over 50. The survival rates at 6, 12, 60, and 120 months for > or = 6 vs <6 U of blood transfusion of 63.8% vs 83.3%; 53.9% vs 76.3%; 40% vs 60%; 34.5% vs 49.2%. In conclusion, we observed that patients receiving over 6 red blood cell units intraoperatively displayed reduced survival. Predictive factors for this risk factor were high donor level of sodium and of age.

Elderly donors for HCV(+) versus non-HCV recipients: patient survival following liver transplantation.

INTRODUCTION: Chronic liver failure due to hepatitis C virus (HCV)-related cirrhosis is the leading indication for liver transplantation. Inferior long-term results have been reported for liver transplantation in HCV(+) patients, especially when marginal donor livers are utilized. AIM: The aim of this study was to analyze retrospectively the outcome of liver transplantation patients from elderly donors in the case of HCV(+) versus non-HCV recipients. METHODS: Among 330 liver transplantations performed from January 1994 to December 2006, we selected 244 excluding acute hepatic failure, children, and retransplants. Among these patients we analyzed 232 subjects who underwent the piggyback technique. Donor risk index (DRI) as described by Feng et al was applied using 1.7 as a cutoff value. We used Kaplan-Meier survival and Cox hazard regression analyses. We studied 14 donor variables using descriptive statistical tests. RESULTS: There were 148 (63.8%) HCV(+) recipients and 84 (36.2%) non-HCV liver transplant recipients. Among HCV(+) recipients, 130/148 (87.8%) patients received livers, from donors less than 50 years old, and 18/148 (12.2%), over 50 years. The descriptive statistics of patient categorical variables are shown in Table 1, and continuous variables in Table 2. The cumulative proportional survival curves are shown in Figs 1 and 2. Mortality predictive factors in HCV(+) liver transplant recipients with donor age > 50 years old as determined by Cox hazard regression showed that death risk was increased with hazard ratios for warm ischemia = 1.01 (P = .001); for red blood cell intraoperative requirements = 2.63 (P = .003); for Child-Turcotte-Pugh classification points = 2.25 (P = .04), and for DRI > 1.7 = 2.19 (P = .03). In conclusion, advancing donor age, as well as the use of nonideal donors, intraoperative bleeding, and prolonged warm ischemia, had an adverse influence on patient survival for HCV(+) recipients.

Survival analysis of obese patients undergoing liver transplantation.

INTRODUCTION: The influence of preoperative obesity in liver transplanted patients remains undetermined. OBJECTIVE: To analyze the survival of obese patients undergoing liver transplantation. METHODS: We calculated the body mass index (BMI; kg/m2) of 244 liver transplantation patients. All transplantations were performed from September 1991 to December 2006. The patients were divided according to the BMI values: nonobese (NO) patients (BMI<30) and obese (O) patients (BMI>30). Pre- and postoperative data were used. The following statistical tests were employed: Student's t test, Kaplan-Meier survival, and Cox-Mantel tests. RESULTS: Group O was composed of 38 individuals (15.3%) with BMI of 33.1, and the BMI of NO was 24. Group O showed an average age of 50.1 years and group NO, 45.5 years (P<.05). Group O postoperative creatinine was higher (P=.001). Both groups had similar MELD scores with an average of 17.5+/-5.9. According to the Child-Pugh classification, group NO included 140 (69.6%) B and 61 (30.3%) C patients; group O, 8 (21%) B and 30 (79%) C patients. There were no significant differences between the groups when comparing cold and warm ischemia times, surgical times, intensive care stay, or blood requirements. The actuarial survivals after 1 and 5 years were 61.3% and 51% for group O and 68% and 47% for NO group (P>.05). A Cox proportional hazard analysis showed that the survival time in this study was related to red blood cell transfusions, recipient sodium, MELD score, donor sodium, and age. Recipient age was a main factor in multiple regression analysis for obese patients in this study. CONCLUSION: There was no significant difference between O and NO for the 1-year and long-term survivals, but older patients displayed lower survival times.

De novo posttransplantation nonlymphoproliferative malignancies in liver transplant recipients.

The risk of developing de novo malignancies after liver transplantation is around 1% per year. The incidence varies from 3% to 15%; it is greater than that in the general population. The potential causes for cancer after solid organ grafting are: chronic immunosuppression and human herpes viral infection. The objective of this paper was to review the medical literature about the subject to verify the incidence of de novo malignancies in our service. We performed retrospective analysis of the medical files of 325 successive patients undergoing orthotopic liver transplantation from September 1991 to December 2006. We analyzed the type of tumor, the risk factors, the treatment modality, and the patient survivals. Recurrences of hepatocellular carcinoma were excluded. There were 5 (1.54%) men of average age 50.2 years, and an 80% mortality rate. Their survival time was affected by the nature of the tumor and by the late manifestations of intestinal obstruction allowing adequate surgical treatment. Four of the patients displayed heavy alcohol and tobacco consumption before transplantation. Screening for premalignant lesions must be strongly encouraged to achieve better postoperative results.

Molecular mechanisms associated with donor-specific microchimerism in peripheral blood of Brazilian patients after liver transplantation.

A large number of studies in liver transplantation have demonstrated allogeneic microchimerism. The clinical and immunologic implications of this finding remain inconclusive, just as the influence of HLA mismatch and donor alloreactivity also are controversial. The present study analyzed the presence of allogeneic microchimerism in liver transplant recipients in relation to donor leukocyte kinetics and rejection episodes. The study was extended to determining the influence of immunogenetic factors in patients after liver transplantation. The presence of allogeneic microchimerism was analyzed on peripheral blood of 50 recipients. DNA extracted from the samples was subjected to typing for HLA-DRB1 and -DQB1 alleles by polymerase chain reactions using sequence-specific primers (PCR/SSP). Microchimerism was identified by nested PCR/SSP. Microchimerism was detected in 72% of patients. There was significant effect of microchimerism on rejection episodes (P=.002), while HLA mismatches did not show significance for one or two mismatches (P=.98). Allogeneic microchimerism detected in the majority of liver transplant patients was observed to be significantly associated with rejection episodes.

Role of choledochojejunostomy in liver transplantation.

AIM: This study analyzes the efficacy and rate of complications related to Roux-en-Y choledochojejunostomy need either as the primary biliary reconstruction during orthotopic liver transplantation (OLT) or to treat biliary complications. METHODS: One hundred seventy-seven transplantation procedures were performed from September 1991 to December 2003 in recipients of mean age 51.9 years. Patients were reviewed for the type of biliary reconstruction, the prevalence of biliary complications, and the choice of treatment for these complications. Duct-to-duct anastomosis (group CDC) was performed in 153 patients (85.6%), and choledochojejunostomy (group CDJ) in 24 patients (14.4%). Biliary complications, including stenosis, bile leakage, calculosis, and extensive biliary necrosis, required hospitalization, surgical interventions or endoscopic approaches. Biliary complications in the CDC group first were addressed by endoscopic treatments. When endoscopic therapy failed, they were approached by surgical reintervention. All biliary complications in group CDJ were surgically treated, namely, revision of the Roux-en-Y choledochojejunostomy. The chi square test was used to compare frequencies, with Yates correction when necessary; P values were considered significant at <.05. The Mann-Whitney U test was used to evaluate survival. RESULTS: Fifty-eight (32.8%) biliary complications in 47 patients required endoscopic or surgical approaches. In group CDJ, 1 patient had bile leakage requiring surgical treatment. The prevalence of biliary complications was lower in the CDJ group than the CDC group (P < .05). Endoscopic treatment applied in 23 patients, failed in 11. Surgical approaches were performed in 11 patients after endoscopic failure, and in 13 patients as the first option to treat biliary complications. No failure was observed with surgical treatment. Cholangitis occurred in 3 patients who received surgical treatment and 4 patients who received endoscopic treatment. There was no statistically significant difference when comparing the mortality rates of the 3 types of treatment for biliary complications: endoscopy, surgery, and endoscopy followed by surgery. Survival rates were similar for the 3 types of treatment of biliary complications. CONCLUSION: Roux-en-Y choledochojejunostomy is a useful tool to treat biliary complications after OLT, especially when endoscopic treatment fails. In our experience, the rate of complications directly related to this technique is significantly lower than common duct anestomosis, whether used for biliary reconstruction during OLT or for posttransplantation biliary complications.

Liver transplant recipients mortality on the waiting list: long-term comparison to Child-Pugh classification and MELD.

We sought to evaluate our experience concerning the high waiting list mortality rate for orthotopic liver transplantation (OLT) using the MELD (Model for End-Stage Liver Disease), which has been shown to predict short-term survival better than Child-Turcotte-Pugh (CTP) classification. The predominant end-stage disease was cirrhosis due to hepatitis C virus (67%), patient mean age was 36.8 years, and 72.1% were men. When the patients were included on a waiting list, the MELD score was stratified into W: 0 to 10; X: 11 to 20, and Y: 21 to 40 and the CPT as A: 5 to 6, B: 7 to 9, and C: 10 to 15. It was also observed that 77.8% of patients were on the waiting list, 16.4% underwent OLT and 5.8% had been removed. The estimated survival rate after 1 year was W = 85.4%; X = 83.3%, Y = 46.8%; A = 81.3%, B = 84.2%, C = 45.9%. Child median score was 8 +/- 1.5 (5 to 15) and the MELD was 14.7 +/- 5.1 (8 to 43). The mortality rate was 20.2%. Severe patients classified as Y or C showed greater mortality than the other groups (P <.001), but no significant difference between Y and C strata. The mortality rate was the same as in previous years.

Development of donor-specific microchimerism in liver transplant recipient with HLA-DRB1 and -DQB1 mismatch related to rejection episodes.

Migration of donor-derived cells to recipient tissues after liver transplantation has been suggested as a mechanism to induce and maintain allograft tolerance, although important issues remain including acute rejection posttransplantation mortality, and complications related to immunosuppressive therapy. We therefore examined the relation of rejection to chimerism based upon recipient and donor mismatch of HLA-DRB1 and -DQB1 alleles. Laboratory analysis of peripheral blood was performed before and 10 days to 16 months after liver transplantation in 32 recipients, using ganglion or spleen cell samples of respective donors. DNA was extracted for HLA-DRB1 and DQB1 allele typing using polymerase chain reactions with sequence-specific primers (PCR-SSP). Microchimerism was analyzed through nested PCR. Our results confirmed that patients with one or two mismatched HLA-DRB1 and-DQB1 alleles showed microchimerism and no rejection (P <.05). Microchimerism was present in 71.88% of the patients, and a significant association of rejection P <.05 was found when microchimerism was correlated to graft rejection. These results suggest that the presence of microchimerism may be associated with acceptance, tolerance and survival of the allograft.

Late hepatic artery thrombosis after liver transplantation: clinical setting and risk factors.

The aim of this study was to assess the prevalence clinical presentation, and impact on outcome of late hepatic artery thrombosis (HAT) after OLT. We also sought risk factors other than technical problems that predispose to the pathogenesis of late HAT among 178 OLT performed from 1999 to 2002. Late HAT was diagnosed using Doppler ultrasonography and arteriography. Late HAT was observed in nine patients (3.8%), all of whom had experienced chronic HCV infection. Median time to HAT diagnosis was 4.88 months after OLT. Mean follow-up time was 40.25 months. Recipient age ranged from 30 to 61 years and median donor age, 28 years. Mean warm ischemia time was 63 minutes and mean cold ischemia time, 660 minutes. All of our study group were cigarette smokers. Postoperative CMV infection, presenting with hepatitis, had been treated in 55.6%. Before the diagnosis of HAT more than one episode of acute cellular rejection had been observed in six patients (55.6%) and 44.5% had chronic rejection. The diagnosis of CR was established after the diagnosis of HAT in all cases. Recurrence of HCV infection was histologically documented in 44.5%. Only one patient experienced graft loss (77 months after OLT). Six of nine patients had biliary complications, treated either by endoscopic stenting or by surgical drainage. Two patients were asymptomatic. In conclusion, late HAT shows a benign presentation that has no impact on graft survival. Possible risk factors have yet to be defined by multicenter trials.

[Indication and results of liver transplantation in adults]. / Indicação e resultados do transplante hepático em adultos.

Increase of survival of patients submitted to transplantation is much superior when compared to other treatments in patients suffering terminal chronic hepatic failure. This fact has been allowing earlier indication of hepatic transplantation in lower operative risk patients. Pre-operative cardiocirculatory evaluation is essential, because during surgery hemodynamic and cardiac output alterations shall occur. The actual survival above 75% suggests that it is easier nowadays to look for factors responsible for mortality than to those predictable by survival. Postoperative survival analysis shows better results in cholestatic diseases (primary biliary cirrhosis and sclerosing cholangitis). Regarding hepatocelular carcinoma over cirrhotic liver, the best results are detected in small lesions up to 3 cm.